Search

Key Points Comparison of the mutation frequencies and numbers of 122 genes in 3096 cases enables identification of “mutation-driven” entities.Differences in mutation patterns in cases with or without CHIP-associated mutations across entities suggest differences in pathophysiology., Visual Abstract, Acquired somatic mutations are crucial for the development of most cancers. We performed a comprehensive comparative analysis of the mutational landscapes and their correlation with CHIP-related (clonal hematopoiesis of indeterminate potential) mutations and patient age of 122 genes in 3096 cases of 28 different hematological malignancies. Differences were observed regarding (1) the median number of mutations (highest, median n = 4; lowest, n = 0); (2) specificity of certain mutations (high frequencies in atypical chronic myeloid leukemia [aCML; ASXL1, 86%], follicular lymphoma [FL; KMT2D, 87%; CREBBP, 73%], hairy cell lymphoma [BRAF, 100%], lymphoplasmacytic lymphoma [MYD88, 98%; CXCR4, 51%], myeloproliferative neoplasm [MPN; AK2, 68%]); (3) distribution of mutations (broad distribution within/across the myeloid/lymphoid lineage for TET2, ASXL1, DNMT3A, TP53, BCOR, and ETV6); (4) correlation of mutations with patient’s age (correlated with older age across entities: TET2, DNMT3A, ASXL1, TP53, EZH2, BCOR, GATA2, and IDH2; younger age: KIT, POT1, RAD21, U2AF2, and WT1); (5) correlation of mutation number per patient with age. Moreover, we observed high frequencies of mutations in RUNX1, SRSF2, IDH2, NRAS, and EZH2 in cases comprising at least 1 DTA (DNMT3A, TET2, ASXL1) mutation, whereas in cases without DTA mutations, TP53, KRAS, WT1, and SF3B1 were more frequent across entities, suggesting differences in pathophysiology. These results give further insight into the complex genetic landscape and the role of DTA mutations in hematological neoplasms and define mutation-driven entities (myelodysplastic syndrome/MPN overlap; secondary acute myeloid) in comparison with entities defined by chromosomal fusions (chronic myeloid leukemia; myeloid/lymphoid neoplasm with eosinophilia).

BACKGROUND: Social determinants and demographics exert an overwhelming influence on the health of the individual and overall population health (J Am Geriatr Soc. PMID: 28369694).The Hispanic paradox has been well characterized, demonstrating that although Hispanic patients (HisP) have higher disability, depressive, metabolic, and inflammatory risk when compared to non-Hispanic (nHisP), they continue to live long lives (J Health Soc Behav. PMID: 31771347). The characterization of these differences in hematology has not been well documented. This study seeks to characterize Lymphoplasmacytic lymphoma (LPL). LPL is a rare lymphoma of B-cell origin demonstrating an incidence of 1000 to 1500 new cases per year in the United States (Hematol Oncol Clin North Am, PMID: 31229160). Epidemiological research is not well documented in this lymphoma subtype, especially regarding the HisP. Given that Texas has the second highest state with HisP in the country (US Census Bureau), we studied the demographics of this disease and specifically researched the demographics, treatment patterns and survival between HisP and nHisP in Texas. METHODS: This is a retrospective study of a cohort of patients diagnosed with lymphoma (Hodgkin and Non-Hodgkin) from the Texas Cancer Registry (TCR) database. Patient's included were those >18 years of age during 2006-2016 and this study focused on the LPL subset. Standard demographic variables collected include gender, race, ethnicity, birthplace, occupation, dates at diagnosis and death, primary payer at diagnosis, subtype of lymphoma, stage, type of treatment, poverty index, and vitality status among others. The significance of variation in the distribution of categorical outcomes with ethnicity (HisP, nHisP) was assessed with Fisher's Exact tests or Pearson's Chi-square tests as appropriate; age was assessed with T-tests or Wilcoxon tests as appropriate. Survival time was measured in years from date of primary diagnosis to date of death. Survival distributions were described with Kaplan-Meier curves and significance of variation in median survival with ethnicity was assessed with log rank testing. All statistical testing was two-sided with a significance level of 5%. RESULTS AND DISCUSSION: Out of 490 patients diagnosed with LPL, 64 were HisP and 426 nHisP. Of this population, the HisP had a higher percentage of patients at the higher end of the poverty index (42.4% to 20% with p value CONCLUSION: In this study we show that in Texas, for those diagnosed with LPL, there is a statistically significant difference in the rates of poverty and insurance when comparing Hisp to nHisP. While this is true, there is no clear statistically significant difference in overall treatment or survival probability, which is consistent with the Hispanic paradox. Due to the rarity of this disease, the population size is limited which may skew the data. More research is needed in order to further characterize the differences between these two populations and determine what can be done to narrow these differences. Disclosures Diaz Duque: ADCT Therapeutics: Research Funding; Molecular Templates: Research Funding; AstraZeneca: Research Funding; Hutchinson Pharmaceuticals: Research Funding; Seattle Genetics: Speakers Bureau; Verastem: Speakers Bureau; AbbVie: Speakers Bureau.

MYD88 L265P is the most common mutation in lymphoplasmacytic lymphoma/Waldenström macroglobulinemia (LPL/WM) and one of the most frequent in poor-prognosis subtypes of diffuse large B-cell lymphoma (DLBCL). Although inhibition of the mutated MYD88 pathway has an adverse impact on LPL/WM and DLBCL cell survival, its role in lymphoma initiation remains to be clarified. We show that in mice, human MYD88L265P promotes development of a non-clonal, low-grade B-cell lymphoproliferative disorder with several clinicopathologic features that resemble human LPL/WM, including expansion of lymphoplasmacytoid cells, increased serum immunoglobulin M (IgM) concentration, rouleaux formation, increased number of mast cells in the bone marrow, and proinflammatory signaling that progresses sporadically to clonal, high-grade DLBCL. Murine findings regarding differences in the pattern of MYD88 staining and immune infiltrates in the bone marrows of MYD88 wild-type (MYD88WT) and MYD88L265P mice are recapitulated in the human setting, which provides insight into LPL/WM pathogenesis. Furthermore, histologic transformation to DLBCL is associated with acquisition of secondary genetic lesions frequently seen in de novo human DLBCL as well as LPL/WM-transformed cases. These findings indicate that, although the MYD88L265P mutation might be indispensable for the LPL/WM phenotype, it is insufficient by itself to drive malignant transformation in B cells and relies on other, potentially targetable cooperating genetic events for full development of lymphoma.

TO THE EDITOR: Waldenstrom macroglobulinemia (WM) is a rare lymphoplasmacytic lymphoma associated with immunoglobulin M monoclonal gammopathy.[1][1] The majority of patients carry the L265P mutation in MYD88,[2][2] whereas 40% of patients carry mutations in CXCR4.[3][3] Mutation status has an

The management of Waldenström macroglobulinemia (WM) has evolved tremendously with recent genomic discoveries that correlate with clinical presentation and could help to tailor treatment approaches. The current diagnosis of WM requires clinicopathological criteria, including bone marrow involvement by lymphoplasmacytic lymphoma cells, a serum immunoglobulin M (IgM) monoclonal paraprotein, and presence of the MYD88 L265P mutation. Once the diagnosis is established, the relationship between the patient’s symptoms and WM should be carefully investigated, because therapy should be reserved for symptomatic patients. Bone marrow involvement and serum levels of IgM, albumin, and β2-microglobulin can be used to estimate the time until treatment initiation. The treatment of WM patients should be highly personalized, and the patient’s clinical presentation, comorbidities, genomic profile, and preferences, as well as toxicity of the treatment regimens, should be taken into account. Alkylating agents (bendamustine, cyclophosphamide), proteasome inhibitors (bortezomib, carfilzomib, ixazomib), anti-CD20 monoclonal antibodies (rituximab, ofatumumab), and Bruton tyrosine kinase (BTK) inhibitors (ibrutinib, acalabrutinib, zanubrutinib) are safe and highly effective treatment options in patients with WM. Because novel covalent and noncovalent BTK inhibitors (tirabrutinib, vecabrutinib, LOXO-305, ARQ-531), BCL2 antagonists (venetoclax), and CXCR4-targeting agents (ulocuplumab, mavorixafor) are undergoing clinical development in WM, the future of WM therapy certainly appears bright and hopeful.

Introduction Immunoglobulin heavy-chain variable genes (IGHV) is critical for the defining epitope binding affinityand B cell differentiation. Lymphoplasmacytic lymphoma/Waldenström macroglobulinemia (LPL/WM) is a heterogeneous diseasewhose role of IGHV usage remains unknown. Besides, the clinical relevance of IGHV repertoire for LPL/WM remain largely unexplored. The aim of our study is to explore the IGH repertoire of LPL/WM in by far the largest series, and to evaluate the correlation between IGH rearrangements and genetic aberrations and clinical characteristics of LPL/WM patients. Methods A total of 162 patients with a diagnosis of LPL/WM were included in this study. Polymerase chain reaction (PCR)amplification of IGHV-IGHD-IGHJ was performed on genomic DNA or cDNA samples using the IGH Somatic Hypermutation Assay v2.0 (Invivoscribe, Technologies, San Diego, US). Sequences were aligned to IMGT (http://www.imgt.org/IMGT_vquest/vquest) and IGBLAST (https://www.ncbi.nlm.nih.gov/igblast/) databases. IGH gene repertoires, mutation status, IGHV CDR3 characteristics, genetic aberrations, MYD88 mutation status and clinical characteristics were collected to evaluate the relevance. Results Productive IGHV-D-J rearrangements were obtained in 136 out of 162 patients (84.0%). The IGHV gene repertoire was remarkably biased in LPL/WM. IGHV3-23 (15.4%), IGHV4-34 (10.3%), IGHV3-7 (8.1%), IGHV3-30 (7.4%) and IGHV3-74 (7.4%) were significantly overrepresented in LPL/WM(Figure 1). Among the 134 IGHD data, the most frequent segment was IGHD3-10 (21/134, 15.7%), followed by IGHD6-13 (18/134, 13.4%) (Figure 2). Among the 134 IGHJ data, IGHJ4 segment was selected in more than half of these rearrangements (70/136; 51.5%), followed by IGHJ6 (23/136; 16.9%) and IGHJ5 (21/136; 15.4%) (Figure 3). Most of the cases were mutated (97.0%) using a 98% IGHV germline homology cutoff. IGHV3-30 was associated with long heavy chain CDR3, indicating the specific antigen selection in LPL/WM. Patients with IGHV3-7 were significantly more likely to harbor 6q deletion (p Conclusion LPL/WM appears to be composed ofdifferent subgroups based on the IGHV repertoire. The mutational status and the IGHV CDR3 length indicated the role for antigenselection in LPL/WM development. The presence of IGHV4 genes proved to be a potential risk factor associated with outcome which deserved further study.These results showed for the first time that IGHV repertoire had clinical relevance in LPL/WM. Figure 1 Figure 1. Disclosures Wang: AbbVie: Consultancy; Astellas Pharma, Inc.: Research Funding.

Despite recent advances in treatment, human precursor B-cell acute lymphoblastic leukemia (B-ALL) remains a challenging clinical entity. Recent genome-wide studies have uncovered frequent genetic alterations involving RAS pathway mutations and loss of the INK4A/ARF locus, suggesting their important role in the pathogenesis, relapse, and chemotherapy resistance of B-ALL. To better understand the oncogenic mechanisms by which these alterations might promote B-ALL and to develop an in vivo preclinical model of relapsed B-ALL, we engineered mouse strains with induced somatic KrasG12D pathway activation and/or loss of Ink4a/Arf during early stages of B-cell development. Although constitutive activation of KrasG12D in B cells induced prominent transcriptional changes that resulted in enhanced proliferation, it was not sufficient by itself to induce development of a high-grade leukemia/lymphoma. Instead, in 40% of mice, these engineered mutations promoted development of a clonal low-grade lymphoproliferative disorder resembling human extranodal marginal-zone lymphoma of mucosa-associated lymphoid tissue or lymphoplasmacytic lymphoma. Interestingly, loss of the Ink4a/Arf locus, apart from reducing the number of apoptotic B cells broadly attenuated KrasG12D-induced transcriptional signatures. However, combined Kras activation and Ink4a/Arf inactivation cooperated functionally to induce a fully penetrant, highly aggressive B-ALL phenotype resembling high-risk subtypes of human B-ALL such as BCR-ABL and CRFL2-rearranged. Ninety percent of examined murine B-ALL tumors showed loss of the wild-type Ink4a/Arf locus without acquisition of highly recurrent cooperating events, underscoring the role of Ink4a/Arf in restraining Kras-driven oncogenesis in the lymphoid compartment. These data highlight the importance of functional cooperation between mutated Kras and Ink4a/Arf loss on B-ALL.

Object:Lymphoplasmacytic lymphoma/ Waldenström's macroglobulinemia (LPL/WM) is a rare B-cell proliferative malignancy characterized by immunoglobulin M monoclonal gammopathy and /or bone marrow infiltration by lymphoplasmacytic cells. Recently, there are no large-scale studies to detect the clinical features, genetic background in patients with LPL/WM in China even Asia. The aim of this study is to explore the clinical and genetic differences, observe the impact of cytogenetic abnormalities on survival and prognosis in Chinese patients. Methods:305 patients with LPL/WM admitted in our hospital from June 1998 to December 2018 were retrospectively analyzed. Baseline characteristics, laboratory detection and therapy were compared using Chi-square test and Kaplan-Meier methodology was undertaken for survival analysis. Results:The median age of 305 patients in the study was 62 years (range 32-87) and male to female ratio was 2.45:1(216/89). The most common symptoms at diagnosis were fatigue (64.9%) and bleeding (14.1%).The patients in low, intermediate and high risk group of the international prognostic scoring system for WM (ISSWM) was 17.6%, 36.5% and 45.9%,respectively.The median hemoglobin was 8.5g/dl(range 2.4-18.7). About 41.3% patients had IgM higher than 4000mg/dl. The cytogenetic abnormalities were uncommon in LPL/WM patients. The chromosomal karyotypes were successful in 194 cases, of which 20 patients showed clonal abnormalities. 12 patients had two or more chromosome abnormalities. The most common chromosome abnormalities were deletion 6/6q(25%) and Y chromosome loss (20%). The median progression-free survival (PFS) and overall survival (OS) in patients with normal and abnormal chromosome karyotypes were similar. 194 patients had FISH detection, of which 33 patients (17%) had FISH abnormalities, 9 (4.6%) patients had two kind of abnormalities. The patients with more than one cytogenetic abnormality had lower survival than just had one abnormality or normal patients. The most common aberrations were 6q deletion and trisomy 12. 17p deletion was detected in 11 patients (11/184,6.0%) and it was a poor prognostic marker of PFS and OS. Single 13q14 deletion had not impact on PFS or OS, but when companied with other cytogenetic aberration, it could worsen the PFS and OS . Besides related to survival, cytogenetic abnormal was also related to the clinical features. Conclusions:Despite the low incidence and abnormal cytogenetic detection rate of LPL/WM, the clinical and genetic features are unique in Chinese patients. The cytogenetic aberrations play an important role in predicting prognosis. Disclosures No relevant conflicts of interest to declare.

BACKGROUND Waldenström Macroglobulinaemia (WM) is an indolent, IgM-producing lymphoplasmacytic lymphoma (LPL) that infiltrates bone marrow (BM) and other tissues. Only symptomatic patients (with IgM-related complications, cytopenias, constitutional symptoms, bulky extramedullary disease) require treatment. Symptomatic BM lesions are not a recognised manifestation of WM and, if present, may raise the possibility of high-grade transformation. AIMS To characterise the clinical, radiological and histological features of focal bone marrow lesions (FBML) identified in WM patients with unrelenting pain in bones and/or joints, and outline implications for treatment. METHODS This study retrospectively reviewed investigations performed at the time of FBMLpresentation, including MRI of the site of pain, total body FDG-PET/CT, review of histology from BM trephine biopsy of the posterior superior iliac spine (PSIS) and CT-guided core biopsy of the identified FBML, and routine blood panels. RESULTS The 6 patients identified (Table 1) presented with localised skeletal pain at different stages of their WM disease course: 1 at initial WM diagnosis, 1 after 10 years of observation, 3 in remission following R-chemotherapy, and 1 during active treatment with R-chemotherapy. Median age at diagnosis of WM was 57 years (41-64 years). Median time from diagnosis to presentation with FBML was 28 months (0-120 months). MRI demonstrated well-defined areas of abnormal signal within the medullae of symptomatic bones and no evidence of cortical or trabecular bone involvement (Fig. 1A), with T1 hypointensity, diffusion restriction and mild STIR hyperintensity in excess of background BM changes. The FBML showed a predilection for the lower limbs (knees, ankles and/or feet involvement in 3 patients, 50%) and periarticular spaces (5 patients, 83%). They were CT-occult and only mildly FDG-avid. In all cases, core biopsies of the FBML showed heavy BM infiltration with diffuse interstitial infiltrate of small, mature lymphocytes (Fig. 1B, 1C) expressing CD20, CD79a and IgM; CD138 staining highlighted scattered interstitial plasma cells ( On blood panels, LDH, ALP and platelet count were normal and Hb was >100g/L in all but the 1 patient with active WM (who had Hb 79g/L and ALP 149IU/L). There was no corresponding rise in paraprotein at the time of FBML presentation. In all cases, the detection of FBML prompted initiation/escalation of systemic treatment despite no evidence of progression using conventional criteria; this resulted in resolution of pain and disappearance of the T1 hypointense lesions on MRI in all cases. CONCLUSION Painful, LPL-dense, infiltrative lesions confined to the BM of affected appendicular bones are an unreported manifestation in WM. They are clinicopathologically different from the osteolytic lesions seen in myeloma and the painless, diffuse BM infiltration seen in low-grade lymphomas and can induce unrelenting focal skeletal pain. Based on our findings, such cases should be evaluated for focal bone marrow lesions; MRI is the preferred modality as lesions are CT-occult. They do not necessarily represent high-grade transformation. This small yet comprehensive series suggests they constitute a hitherto undescribed novel indication for systemic therapy irrespective of the general disease status. Disclosures D'Sa: Janssen:Honoraria, Research Funding;BeiGene:Honoraria, Research Funding;Sanofi:Honoraria.

Primary cold agglutinin disease (CAD) is a rare autoimmune hemolytic anemia mediated by monoclonal IgM autoantibodies directed against the I antigen on erythrocytes. CAD is due to a B-cell lymphoproliferative disorder of the bone marrow. We have previously reported recurrentKMT2DandCARD11mutations and trisomy 3 and 12 or 18 in CAD patients (Malecka et al., 2018 & 2020). In addition, we have revealed that the cold-reactive antibody is highly stereotyped (Malecka et al., 2016). In this study, we present new and detailed data on the mutation landscape of CAD patients. We have analyzed the bone marrow from 14 patients with CAD, included in a recent clinical trial (Berentsen et al., 2017), by whole exome sequencing. Clonal B cells and normal T cells (normal control) were acquired using fluorescence-activated cell sorting. The data from whole exome sequencing were aligned to the human genome hg38 and analyzed as described before (Malecka et al., 2020). Variant discovery and functional annotation were performed with the use of GATK4 tools: Mutect2 and Funcotator. Detected mutations were validated manually using IGV browser. The total amount of non-synonymous mutations detected in each CAD sample ranged from 13 to 62, while the total amount of all mutations in the exome regions ranged from 36 to 163 (Figure 1A). Four genes showed non-synonymous mutations in 3 or more cases, these are:KMT2D(8/14; 57%),IGLL5(5/14; 36%),CARD11(3/14; 21%),CXCR4(3/14; 21%) (Figure 1B and Table 1). Additionally, several genes showed non-synonymous mutations in 2 of the 14 cases (14%):PHLDB1, HIST1H1E, LPIN3, LTB, MACF1, NBEA, NEFH, PCNX2, RRAGC, TMPRSS7, ZNF618(Figure 1B). A majority of these genes are also found mutated in lymphoma. All patients with eitherCARD11orCXCR4mutations have concurrentKMT2Dmutations. One patient has bothCARD11andCXCR4mutations together withKMT2Dmutation. Recurrent mutations seem to cluster in some of the cases (Figure 1C). Almost all patients with aKMT2Dmutation (7/8, 87%) have at least 3 other recurrent mutations. Patients with aCARD11(3 cases) or aCXCR4(3 cases) mutation have at least 3 other recurrent mutations. KMT2Dmutations are found in many lymphomas and are associated with Kabuki syndrome. It is suggested thatKMT2Dis a tumor suppressor gene, andKMT2Dmutations might act as driver mutations in many lymphomas. In addition,CARD11mutations in our cases are located in coiled-coil domain in exon 6, and therefore it is expected to result in NF-kB activation (Malecka et al. 2018).IGLL5is located in the IG lambda locus. The function of theIGLL5gene is unknown, but it is homologues to theIGLL1gene known to be important in B cell development.IGLL5mutations are seen in lymphoma as well as other malignancies and might have some prognostic value in diseases like multiple myeloma.CXCR4has been implicated in the migration and trafficking of malignant B cells in several hematological malignancies.CXCR4mutations are frequently seen in lymphoplasmacytic lymphoma, and almost always in combination with aMYD88mutation. In our series, aCXCR4mutation always occurs in combination with aKMT2Dmutation.MYD88was not found to be mutated. Detected mutations in theCXCR4gene are of potential therapeutic interest, sinceCXCR4inhibitors exist. CAD patients with aKMT2Dmutation associated with other recurrent mutations (Figure 1C), show a trend to lower hemoglobin levels at diagnosis compared to patients with noKMT2Dmutation or patients withKMT2Dmutation without other recurrent mutations. We are currently working on sequencing clonal B cells from additional patients in order to confirm these findings. In conclusion, CAD-associated lymphoproliferative disease shows a relatively low mutation burden. but with recurrent gene mutations. The most common recurrent mutations are in genes known to be involved in lymphoma development. Our preliminary data suggest thatKMT2Dmutation associated with other recurrent mutations might determine severity of hemolysis. Disclosures Tierens: Amgen:Membership on an entity's Board of Directors or advisory committees;Jazz Pharmaceuticals:Membership on an entity's Board of Directors or advisory committees;Astellas Pharma:Membership on an entity's Board of Directors or advisory committees.Berentsen:Mundipharma:Research Funding;Apellis Pharmaceuticals:Consultancy, Other: lecture honoraria;Bioverativ:Consultancy, Other: lecture honoraria;Janssen-Cilag:Other: lecture honoraria;Momenta Pharmaceuticals:Consultancy;True North Therapeutics:Other: lecture honoraria;Alexion Pharmaceuticals, Inc,:Other: lecture honoraria.Tjønnfjord:Mundipharma:Other: A grant from Mundipharma to cover the expenses of bendamustine for the CAD5 study.

Background: Indolent B-cell lymphomas are a group of neoplastic disorders that account for approximately one-third of non-Hodgkin lymphomas in the Western world. They are clinically indolent but pathologically diverse and generally composed of follicular lymphoma (FL), extranodal marginal zone lymphoma (EMZL), lymphoplasmacytic lymphoma (LPL), nodal marginal zone lymphoma (NMZL), splenic marginal zone lymphoma (SMZL), and small lymphocytic lymphoma. The overall prognosis is favorable in most patients, but others can have a more aggressive disease with associated progression, relapse, or histologic transformation. We have previously reported that the most common cause of death in FL was lymphoma. Here we report on the cause of death (COD), in other non-follicular indolent B-cell lymphomas (NFIBL) during the first decade of the rituximab era. Methods: Participants were from the Molecular Epidemiology Resource (MER) of the University of Iowa/Mayo Clinic Lymphoma Specialized Program of Research Excellence (SPORE). From 2002 -2015, MER offered enrollment to all patients with newly diagnosed lymphoma who were US residents and age >18 years. Patients were treated per physician choice and followed prospectively. An event was defined as progression or relapse, initiation of 2nd line therapy, or death from any cause. EFS24 was defined using event-free survival at 24 months from diagnosis. Overall survival was defined as the time from diagnosis until death due to any cause. Overall survival from EFS24 was defined as time from event defining date (achieving EFS24 or early event). For decendents, copies of the death certificate or medical records associated with death were reviewed. Cumulative incidence estimates of the cause of death in NFIBL were calculated as competing risks utilizing the cuminc function from the cmprsk package in R version 3.6.2. COD was categorized as a result of lymphoma (progression or therapy-related) vs. other causes vs. unknown/missing. Results: 820 patients with newly diagnosed NFIBL were enrolled in this study. The subtypes included extranodal marginal zone (EMZL, N = 362), unclassifiable low-grade B-cell lymphoma (LGBCL-U, N = 202), lymphoplasmacytic lymphoma (LPL, N = 92), nodal marginal zone lymphoma (NMZL, N = 80), and splenic marginal zone lymphoma (SMZL, N = 84). The median age at diagnosis was 63 years (range 18-92), and 50.5% were male. Baseline clinicopathologic characteristics showed that the LDH was abnormal in 19.3%, hemoglobin was abnormal in 33.8%, and 62.8% had stage III-IV disease. The IPI score was 0-1 in 51%, 2 in 36.6%, 3 in 10.6%, and 4-5 in 1.8%. At a median follow-up of 83 months (range 0-193), 172 (21%) patients had died, and the primary cause of death was non-lymphoma related in 87 (50.6%), lymphoma related 48 (27.9%), and unknown in 37 (21.5%). When examining all subtypes combined, the 10-year estimate for lymphoma related death was 7% (95% CI: 5.2-9.5) which was lower than the rate of non-lymphoma related death (10 years estimate 14%, 95% CI: 11.3-17.4), Figure 1A, Table 1. The 10-year estimate of lymphoma related death varied by subtype, ranging from 2.7% in EMZL to 16.3% in LPL (table 1), while non-lymphoma related death at 10 years ranged from 10.2% in EMZL to 22.5% in SMZL; only in LPL was the lymphoma related rate higher than the non-lymphoma. Patients who failed to achieve EFS24 from diagnosis had significantly higher rates of lymphoma related death (18% at 10 years from failure, 95% CI: 11.7-29.1, Figure 1B) compared to patients who achieved EFS24 (3.9% at 10 years from achieving EFS24, 95% CI: 2.3-6.8, Figure 1C). Rates were similar by EFS24 for non-lymphoma related death (14.5%, 95% CI: 11.0-19.0 vs. 11.2, 95% CI: 6.3-19.7). Figure 1B-C. Conclusion: The most common cause of death in NFIBL at 10 years was unrelated to lymphoma, in contrast to our previous data in follicular lymphoma which showed lymphoma as the most common cause of death at 10 years. However, similar to follicular lymphoma, patients with NFIBL who failed to achieve EFS24 to frontline therapy had significantly increased risk of lymphoma related death. Further research into the cause of death in NFIBL is warranted. Disclosures Maurer: Celgene / BMS: Research Funding; Morphosys: Membership on an entity's Board of Directors or advisory committees; Kite: Membership on an entity's Board of Directors or advisory committees; Pfizer: Membership on an entity's Board of Directors or advisory committees; Nanostring: Research Funding. Witzig:Celgene: Consultancy, Research Funding; MorphSys: Consultancy; AbbVie: Consultancy; Incyte: Consultancy; Acerta: Research Funding; Karyopharm Therapeutics: Research Funding; Immune Design: Research Funding; Spectrum: Consultancy. Novak:Celgene/BMS: Research Funding. Farooq:Kite, a Gilead Company: Honoraria. Cerhan:BMS/Celgene: Research Funding; NanoString: Research Funding.

Histologic transformation (HT) is a frequent event in the clinical course of patients with indolent lymphoma. Most of the available data in the literature comes from studies on transformation of follicular lymphoma (FL), as this is the most common indolent lymphoma; however, HT is also well documented following small lymphocytic lymphoma/chronic lymphocytic leukaemia (SLL/CLL), lymphoplasmacytic lymphoma (LPL), or marginal zone lymphoma (MZL), amongst other types of lymphoma, albeit most of the studies on transformation in these subtypes are case reports or short series. The outcome of patients with HT has traditionally been considered dismal with a median overall survival (OS) of around 1 year in most of the published studies. This prompted many authors to include stem cell transplant (SCT) as part of the treatment strategy for young and fit patients with HT. However, recent articles suggest that the outcome of patients with transformed lymphoma might be improving, questioning the need for such intensive therapies. The management of patients with HT is challenged by the heterogeneity of the population in terms of previous number and type of therapy lines and from their exclusion from prospective clinical trials. This review will examine whether the advent of new therapies has impacted on the prognosis of HT and on current treatment strategies.

Chronic lymphocytic leukemia (CLL) and lymphoplasmacytic lymphoma (LPL) are malignancies of mature B cells. In LPL, mutations of the adaptor protein MYD88 (L265P) in the Toll-like receptor pathway have been recognized recently as being a hallmark of the disease and indicate a dependence of the tumor on this pathway. In CLL, functional studies have implicated BCR activation in the tissue microenvironment as a pivotal pathway in the pathogenesis. Bruton's tyrosine kinase (BTK) and the PI3Kδ isoform are essential for BCR signaling and also seem to be required for signal transduction in LPL cells, even if the role of BCR signaling in this disease remains less well defined. Ibrutinib, a covalent inhibitor of BTK approved by the Food and Drug Administration as a second-line treatment for CLL, and idelalisib, a selective inhibitor of PI3Kδ, achieve excellent clinical responses in both diseases irrespective of classic markers indicating high-risk disease. Several additional inhibitors targeting BTK and PI3Kδ, as well as the spleen tyrosine kinase, have entered clinical trials. This review discusses the biologic basis for kinase inhibitors as targeted therapy for CLL and LPL and summarizes the clinical experience with these agents.

Lymphoplasmacytic lymphoma (LPL) is a distinct B-cell lymphoproliferative disorder primarily characterized by bone marrow infiltration of lymphoplasmacytic cells. When LPL produces a serum monoclonal immunoglobulin of the IgM class, it is termed Waldenström macroglobulinemia (WM). The differential diagnosis between LPL and other types of morphologically similar B-cell tumors that may also have plasmacytic differentiation and/or secretion of IgM paraproteins is not always clear-cut based solely on the pathologic and phenotypic features of the tumor. Although the current treatments for LPL/WM are initially effective in inducing responses in most patients, they are not curative and show decreasing efficacy with repeated administrations, ultimately resulting in the selection of a chemoresistant clone. Next-generation sequencing studies have identified somatic mutations of MYD88, a key component of the Toll-like receptor signaling machinery, in ∼90% of LPL/WM. Deregulated MYD88 signaling promoted by mutations sustains tumor cell survival in LPL/WM, demonstrating that they are gain-of-function driver events in this lymphoma. This review discusses the molecular and biological mechanisms underlying MYD88 mutations in LPL/WM, the role of MYD88 mutations as molecular biomarker for the refinement of diagnosis and the improvement classification of LPL/WM, and novel targeted therapeutic strategies for LPL/WM based on the pharmacological manipulation of MYD88 signaling to which this lymphoma is addicted.

The C-X-C chemokine receptor type 4 (CXCR4) plays a crucial role in modulating cell trafficking in hematopoietic stem cells and clonal B cells. We screened 418 patients with B-cell lymphoproliferative disorders and described the presence of the C1013G/CXCR4 warts, hypogammaglobulinemia, infections, and myelokathexis-associated mutation in 28.2% (37/131) of patients with lymphoplasmacytic lymphoma (Waldenström macroglobulinemia [WM]), being either absent or present in only 7% of other B-cell lymphomas. In vivo functional characterization demonstrates its activating role in WM cells, as demonstrated by significant tumor proliferation and dissemination to extramedullary organs, leading to disease progression and decreased survival. The use of a monoclonal antibody anti-CXCR4 led to significant tumor reduction in a C1013G/CXCR4 WM model, whereas drug resistance was observed in mutated WM cells exposed to Bruton's tyrosine kinase, mammalian target of rapamycin, and phosphatidylinositol 3-kinase inhibitors, but not proteasome inhibitors. These findings demonstrate that C1013G/CXCR4 is an activating mutation in WM and support its role as a critical regulator of WM molecular pathogenesis and as an important therapeutic target.

Background:The isolation of cell-free DNA (cfDNA) evolved the concept of liquid biopsy. Several works have analyzed the presence of cfDNA in lymphomas, especially in diffuse large B-cell lymphoma (DLBCL) and Hodgkin lymphoma (HL), however there is limited information regarding the detection of cfDNA in other types of lymphomas or the role of cfDNA detection to monitor disease outcome. Objectives:1.- To analyze the presence of cfDNA at diagnosis of patients with lymphoproliferative malignancies. 2.- To evaluate the change in concentration of cfDNA ([cfDNA]) after treatment in DLBCL patients. Material and Methods:A retrospective study in a single center was performed including 221 adult patients since January 2015 to February 2019 with: DLBCL, HL, marginal zone lymphoma (MZL), follicular lymphoma (FL), chronic lymphocytic leukemia (CLL), mantle cell lymphoma (MCL), lymphoplasmacytic lymphoma (LPL) and peripheral T-cell lymphomas (TCL). All patients had plasma samples collected at diagnosis that were stored in the institutional biobank (MarBiobank). The cfDNA were obtained from 1 mL of -80°C frozen stored plasma using the MagMax Cell Free DNA isolation kit (Thermo Fisher Scientific). The cfDNA quantification was performed using the Qubit system with the dsDNA high sensitivitykit (Thermo Fisher) and is expressed as ng/mL of plasma. In addition, patients with DLBCL who were treated with rituximab-CHOP/CHOP-like regimens were evaluated for [cfDNA] analysis, pre and post-treatment, and results were compared with PET-CT scan findings. Results: Stored plasma samples at diagnosis were available in 221 patients: DLBCL 82, HL 22, CLL/LPL 13, FL 36, MZL 37, MCL: 11, TCL 10 and others 10 (B-cell lymphoma unclassified, hairy cell leukemia, Burkitt lymphoma). Successful identification of cfDNA was obtained in 95.9% (212/221) of samples. DLBCL patients showed higher [cfDNA] globally and, DLBCL, HL and FL patients showed a higher concentration than MZL who exhibited the lower concentration of all groups (p=0.009; p=0.013 and p=0.002); see table 1. 50 DLBCL patients with a median follow-up since diagnosis of 25.5 (5-51) months were analyzed. Median age was 67 (19-79) years, males 56% (28). IPI distribution: low-risk 28% (14), low-intermediate 26% (13), high-intermediate 24% (12) and high risk 22% (11) cases. Detection of cfDNA was successful in 100% at diagnosis and in 98% (49) cases post-therapy. The mean [cfDNA] at diagnosis was 2.21 (standard deviation- SD: 1.60) ng/mL with a correlation with LDH concentration (p After therapy 86% (43) of patients achieved at least PR (41 complete response), and the mean [cfDNA] for these patients was 1.58 (SD 1.96); patients who showed no response or progressive disease after therapy exhibited higher [cfDNA] 21.25 ng/mL (SD 41.91)(p Conclusions:Isolation of cfDNA was feasible in >95% of lymphoma patients independently of histology or disease stage. Patients with DLBCL exhibited the higher cfDNA concentration which were also correlated with LDH concentrations and high-risk IPI. Kinetics of [cfDNA] is related to response to therapy in DLBCL and also might detect relapse. Even though additional studies are necessary, monitoring of cfDNA may help in management of patients with DLBCL. Disclosures Salar: Roche: Research Funding, Speakers Bureau; Janssen Pharmaceuticals: Consultancy, Speakers Bureau; Gilead: Consultancy, Speakers Bureau; Celgene: Consultancy. Sanchez-Gonzalez:Takeda: Consultancy, Speakers Bureau; Alexion: Speakers Bureau; Gilead: Speakers Bureau; Shire: Speakers Bureau; Novartis: Consultancy, Speakers Bureau; Amgen: Consultancy, Speakers Bureau. Gimeno:JANSSEN: Consultancy, Speakers Bureau; Abbvie: Speakers Bureau. Bellosillo:Qiagen: Consultancy, Speakers Bureau; TermoFisher Scientific: Consultancy, Speakers Bureau.

Introduction: Flow cytometric (FC) immunophenotyping is an essential tool for the diagnosis of mature B cell lympho-proliferative disorders (B-LPDs). The most common CD5-negative/CD10-negative B-LPDs are hairy cell leukemia, lymphoplasmacytic lymphoma and marginal zone lymphoma. Although HCL has unique clinicopathologic characteristics, LPL and MZL are often difficult to distinguish by standard diagnostic methods. MYD88 L265P mutations are found in 90% of LPL and 8-10% of MZL, although the finding of this mutation may increase the suspicion of LPL, it is by no means definitive since they are also found in MZL. The distinction between LPL and MZL is of increasing clinical importance given treatment options and prognosis may differ. The Euroflow eight color B-LPD panel provides detailed information on the phenotype of clonal B-cells and has not previously been evaluated as a tool to distinguish these subtypes of B-LPD. Methods: A retrospective study of patients who were diagnosed with CD5-negative/CD10-negative B-LPD from January 2011 to October 2017 was conducted. Patients with HCL and diffuse large B cell lymphoma were excluded. Data collected included the FC immunophenotype, clinical findings, MYD88 mutational status, treatment and outcome. Data were obtained from the FC lab database at the National University Health System (NUHS) Hematology laboratory. Clinical data were obtained from the electronic patient medical records. A clinicopathologic diagnosis of either LPL, MZL or "indeterminate between LPL/MZL" was assigned to the patients based on consensus at the multidisciplinary tumor board. The FC phenotype (based on raw median fluorescence intensity values) of patients assigned to each diagnostic category were then compared. Hierarchical clustering using Gower's distance of variables and Ward's D linkage method were used to determine if the FC immunophenotyping patterns can distinguish LPL and MZL. Results: A total of 22 patients' data was included in the analysis. We found that the LPL cases formed a discrete cluster, while MZL cases were more widely dispersed (figure 1). LPL cases showed negative expression of CD 39, CD 43 and CD 95, while these markers are expressed in a significant proportion of MZL cases. In contrast, CD31 was expressed in the majority of LPL but not the MZL cases. CD 200 and CD38 were found to be variably expressed in both LPL and MZL cases. It is noteworthy that CD 27 was also not consistently expressed across all the cases in our study. There were also no significant differences in terms of surface IgM expression. Conclusions: Our study showed that the eight color flow cytometry has potential as a tool to differentiate LPL and MZL. The lack of a discrete clustering of the MZL cases in our analysis may be explained by the fact that MZL is a more heterogeneous entity compared to LPL. Positivity for CD31 and negativity for CD39, CD95 and CD43 appear to be features of LPL. MZL in contrast show positive expression of CD39, CD95 and CD43 and are negative for CD31. Earlier studies using four color FC suggested that CD200 may have value as a discriminative marker between LPL and MZL. Our data using eight color FC does not show the same discriminative power for CD200. The absence of consistent CD39 and CD27 expression is unusual as LPL and MZL are both post germinal centre B cell neoplasms in which the expression of these antigens is expected. We propose that FC immunophenotyping should be evaluated prospectively as an adjunct to standard clinicopathologic evaluation to distinguish LPL and MZL. Figure 1 Disclosures No relevant conflicts of interest to declare.

Background: Waldenström Macroglobulinemia (WM) or Lymphoplasmacytic Lymphoma (LPL) is an indolent B-cell neoplasm accounting for only 1-2% of all hematological malignancies. More than 90% of patients with WM carry a point mutation L265P in the MYD88 gene which promotes tumor survival and is shown to be significant for diagnostic and risk stratification. Criteria for diagnosis requires presence of serum monoclonal IgM protein and > 10% bone marrow lymphocytes with plasmacytoid differentiation. We aimed to present the patients characteristics and survival outcomes of WM/LPL patients treated at our center, according to their MYD88 gene status. Methods: We reviewed medical records of all patients diagnosed with WM/LPL between May 2002 and May 2018 for whom MYD88 status was known. Baseline demographic characteristics, ECOG PS, pertinent laboratory values including IgM level at diagnosis, initial therapy, mutation status and cytogenetics was obtained. Kaplan-Meier survival estimation curves were used to illustrate the probability of survival over time stratified by MYD88 status and compared by the log rank test. Results: A total of 99 patients diagnosed with WM/LPL were included, 91 Caucasians (92%), 54 (55%) male, median age 67 years (range, 43-89) and with 63 (64%) patients having ECOG PS 0 or 1. IgM level at diagnosis was available for 88 patients, with a median of 2055 mg/dL (range, 10-11,700) and serum free light chain ratio was estimated at a median of 2.13 (range, 0.01- 37331). Other pertinent laboratory data were: median hemoglobin 11.4 g/dL (range, 6.2- 16.4), median serum viscosity 2.4 CP (range, 1.5- 6.7), median serum M protein 1.4 g/L (range, 0- 5.84), median 24 hour urine protein 11mg (range, 4- 1344) and median serum LDH 173 U/L (range, 71-476). The median international prognostic score (ISSWM) for our cohort was 3. A mutant MYD88 was positive in 85 (86%) patients, while 14 (14%) patients had wild- type MYD88. Complex karyotype was present in 24 (25%) patients. Rituximab monotherapy was the initial treatment in 48 (49%) patients. Twenty-two [22%] patients each received bortezomib-based and bendamustine-rituximab regimen as initial therapy and 7 (7%) patients received frontline rituximab- chemotherapy. Median follow-up of the cohort was 2.8 years (0.08-15.5). At last follow-up, 25 (25%) patients had died. Median OS from diagnosis for the entire cohort was 7.9 years (95% CI, 6.6 to N.R.). OS rate at 5 years was 0.73 (95% CI, 0.61 to 0.87). Patients with mutant MYD88 had significantly longer median OS as compared to those with wild-type MYD88 - 16.3 years (95% CI, 6.7 to N.R.) vs 6.6 years (95% CI, 1.9 to N.R.) [P=0.01] (Figure 1). Conclusion: Within the limitations of a retrospective study with a heterogeneously treated cohort, these data add to the body of literature supporting that outcomes of patients wild-type for MYD88 are worse than those with the L265P mutation when treated with rituximab alone, a proteasome inhibitor or conventional rituximab- chemotherapy. Also, despite an expansion on the therapeutic landscape, the treatment of choice in Waldenström Macroglobulinemia is still lead by rituximab monotherapy in newly diagnosed patients. Further studies should investigate the prognostic impact of MYD88 mutation in the context of BTK inhibitors. Disclosures Hill: Celegene: Consultancy, Honoraria, Research Funding; Seattle Genetics: Consultancy, Honoraria; Takeda: Research Funding; Amgen: Research Funding; TG therapeutics: Research Funding; Pharmacyclics: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Abbvie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Genentech: Consultancy, Research Funding; Kite: Consultancy, Honoraria; Gilead: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; AstraZeneca: Consultancy, Honoraria.

Introduction: Marginal zone lymphoma (MZL) and lymphoplasmacytic lymphoma (LPL)/Waldenstrom's macroglobulinemia (WM) comprise approximately 7% and 2%, respectively, of non-Hodgkin's lymphomas (NHL) (Teras 2016). MZL is further subclassified as splenic MZL (sMZL), nodal MZL (nMZL), or extranodal MZL (eMZL). Standard first-line therapies for LPL/WM include rituximab plus an alkylating agent and/or proteasome inhibitor or ibrutinib (Castillo 2017), while standard first-line treatment for MZL varies by subtype (Rosand 2017). There are limited treatment options for patients who have relapsed after first-line therapy. Idelalisib, a selective oral inhibitor of PI3Kδ, demonstrated efficacy in indolent NHL (iNHL), including MZL and LPL/WM, at a median follow-up of 9.7 months (mos) in a phase 2 study (NCT01282424; 101-09; Gopal 2014). Here, we present the final, long-term results for patients with double-refractory MZL and LPL/WM from the 101-09 study. Methods: Eligible iNHL patients had measurable disease and were refractory to both rituximab and an alkylating agent. Refractory status was defined as lack of response to or progression of lymphoma within 6 mos of completion of preceding therapy, documented by imaging. Oral idelalisib 150 mg twice daily was administered continuously until disease progression or intolerance. Responses were evaluated by an independent review committee using standard criteria (Cheson 2007; Owen 2013). Endpoints included overall response rate (ORR), time to response, duration of response (DOR), lymph node response, progression-free survival (PFS), overall survival, and safety. The final data cutoff date was 22 Oct 2018. Results: Of 125 patients enrolled, 15 (12%) had MZL (sMZL, n = 1; nMZL, n = 5; eMZL, n = 9) and 10 (8.0%) had LPL/WM. Median age was 65 years and most were non-Hispanic (n = 24; 96%) and White (n = 23; 92%). At diagnosis, 80% of MZL and 100% of LPL/WM patients had stage IV disease. The largest lesion at baseline was ≥5 cm for 5 (33%) MZL and 3 (30%) LPL/WM patients. Baseline median IgM level was elevated for 80% of LPL/WM patients (median 1.9, IQR 1.0-2.7 g/dL). Baseline beta2-microglobulin level was >3 µg/mL for 1 of 9 LPL/WM patients with values recorded (median 2.5 [range 1.7-3.1] µg/mL). For MZL and LPL/WM patients, 7 (47%) and 7 (70%) had ≥3 prior therapies, respectively. Common regimens for all 25 patients included rituximab-cyclophosphamide-doxorubicin-vincristine-prednisone (44%), rituximab-cyclophosphamide-vincristine-prednisone (40%), rituximab only (28%), bendamustine only (24%), and bendamustine-rituximab (20%). For MZL, the ORR (95% confidence interval [CI]) was 47% (21%, 73%), with median duration of therapy of 6.4 (range 1.8-37) mos. Of 7 responders, 1 had a complete response and 6 had partial responses (PR). Seven had stable disease (SD) and 1 had progressive disease (PD). Fourteen (93%) patients had reduction in lymph nodes, with 8 (53%) having ≥50% reduction in the sum of the products of the greatest perpendicular diameters (SPD). Median PFS was 6.6 (95% CI 3.5, 22) mos and median DOR was 18 (range 0-18) mos (Table). For LPL/WM, the ORR (95% CI) was 80% (44%, 98%), with a median duration of therapy of 29 (range 6.4-51) mos. Of 8 responders, 7 had PR and 1 had a minor response. There was 1 SD and 1 PD. Nine (90%) patients had lymph node reduction, with 5 (50%) having ≥50% reduction in SPD. Median PFS was 22 (95% CI 1.4, 56) mos and median DOR was 20 (range 1.7-50) mos (Table). All 25 patients had ≥1 treatment-emergent adverse event (TEAE), 16 (64%) had a serious AE, and 11 (44%) had dose reduced due to a TEAE. Grade ≥3 TEAEs occurred for 22 (88%) patients; neutropenia (n = 7, 28%), diarrhea (7, 28%), alanine aminotransferase increased (4, 16%), asthenia (3, 12%), and pneumonia (3, 12%) were the most frequent. All patients eventually discontinued treatment due to disease progression (14, 56%), AE (6, 24%), death (3, 12%), investigator request (1, 4%), or other (1, 4%). Ten patients have died, 3 during the study and 7 during the long-term follow-up. Conclusions: Monotherapy with idelalisib showed high rates of antitumor activity in this small subset of patients with MZL and LPL/WM refractory to prior therapy with rituximab and an alkylating agent; prolonged disease control was achieved for LPL/WM patients. No new safety signals were identified despite longer follow-up. Disclosures Wagner-Johnston: Bayer: Membership on an entity's Board of Directors or advisory committees; Jannsen: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees; ADC Therapeutics: Membership on an entity's Board of Directors or advisory committees. Schuster:Genentech: Honoraria, Research Funding; Celgene: Honoraria, Research Funding; Novartis: Honoraria, Patents & Royalties: Combination Therapies of CAR and PD-1 Inhibitors with royalties paid to Novartis, Research Funding; AstraZeneca: Honoraria; Pharmacyclics: Honoraria, Research Funding; Merck: Honoraria, Research Funding; Acerta: Honoraria, Research Funding; Loxo Oncology: Honoraria; Nordic Nanovector: Honoraria; Pfizer: Honoraria; AbbVie: Honoraria, Research Funding; Gilead: Honoraria, Research Funding. de Vos:Verastem: Consultancy; Portola Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees; Bayer: Consultancy. Salles:Epizyme: Consultancy, Honoraria; Roche, Janssen, Gilead, Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Educational events; Amgen: Honoraria, Other: Educational events; BMS: Honoraria; Merck: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Educational events; Novartis, Servier, AbbVie, Karyopharm, Kite, MorphoSys: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Educational events; Autolus: Consultancy, Membership on an entity's Board of Directors or advisory committees. Jurczak:Bayer: Research Funding; AstraZeneca: Membership on an entity's Board of Directors or advisory committees, Research Funding; Incyte: Research Funding; Sandoz: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novo Nordisk: Research Funding; Celtrion: Research Funding; MorphoSys: Research Funding; Gilead: Research Funding; Roche: Research Funding; Servier: Research Funding; Takeda: Research Funding; TG Therapeutics: Research Funding; Loxo: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding. Rajakumaraswamy:Gilead Sciences, Inc.: Employment. Xing:Gilead Sciences, Inc.: Employment. Gopal:Seattle Genetics, Pfizer, Janssen, Gilead, Sanofi, Spectrum, Amgen, Aptevo, BRIM bio, Acerta, I-Mab-pharma, Takeda, Compliment, Asana Bio, and Incyte.: Consultancy; Teva, Bristol-Myers Squibb, Merck, Takeda, Seattle Genetics, Pfizer, Janssen, Takeda, and Effector: Research Funding; Seattle Genetics, Pfizer, Janssen, Gilead, Sanofi, Spectrum, Amgen, Aptevo, BRIM bio, Acerta, I-Mab-pharma, Takeda, Compliment, Asana Bio, and Incyte: Honoraria. OffLabel Disclosure: Idelalisib is a selective oral inhibitor of PI3K-delta that has shown antitumor activity in previously treated indolent non-Hodgkins lymphomas in phase 1 and 2 studies. It is approved for treatment of relapsed follicular lymphoma that has progressed on 2 prior systemic therapies, relapsed chronic lymphocytic leukemia in combination with rituximab when rituximab alone would be considered appropriate due to other comorbidities, and relapsed small lymphocytic lymphoma that has progressed on 2 prior systemic therapies. In this presentation, we provide results of 2 less common subgroups of indolent non-Hodgkins lymphoma, Âmarginal zone lymphoma and lymphoplasmacytic lymphoma/Waldenstrom's Macroglobulinemia, Âfrom the completed phase 2 trial with long-term follow-up.

Background: Lymphoplasmacytic lymphoma (LPL) secreting immunoglobulins other than IgM is rare. Therefore, there are very few case series on non-IgM LPL and little is known about the clinical features and outcomes of patients with this disease. Aim: To describe disease characteristics and clinical outcomes of patients with non-IgM LPL. Methods: We identified cases of non-IgM LPL in the records of the Waldenström Macroglobulinemia (WM) clinic at our institute, between the years of 2000-2018. All patients were part of the clinic's registry. We extracted data from their electronic records and included only cases with centrally-confirmed diagnosis. Response assessment was based on 6th IWWM criteria. Time to events was estimated using the Kaplan-Meier method. Results: We found 31 patients with non-IgM LPL. Median age at diagnosis was 63 years (range, 37-83 years), 45% were over the age of 65, and 65% were women. The paraprotein secreted by these tumors was IgG in 20 cases (65%); IgA in 5 (16%), light-chain (LC) in 2 (6%) and was non-secretory (NS) in 4 (13%). Median level of IgG and IgA at diagnosis was 3,967 mg/dl (range, 804-8,006 mh/dl) and 1,980 mg/dl (range, 1,020-6,210 mg/dl), respectively. We included 5 cases with concurrent IgM paraproteinemia, when it was clearly secreted to a lesser extent than dominant immunoglobulin and had similar LC restriction. Five patients had MGUS preceding diagnosis of LPL. Presenting symptoms were anemia-related (n=13), asymptomatic (n=7), neuropathy, autoimmune phenomena, elevated creatinine, bleeding diathesis and recurrent infections (n=3, each). Only 1 patient had B-symptoms. One patient with IgA LPL and serum IgA level of 4,000 mg/dl presented with retinal vein occlusion due to hyperviscosity. Non-bulky (3 mg/L in 48% of available patients (n=12/24). All bone marrow biopsies showed that malignant cells were positive for CD20 and CD19 by flow cytometry; 14% were CD5 positive (subset/dim); 29% CD23 partially-positive; and all were CD10 negative. Five of 19 cases (26%) had cytogenetic abnormalities, but apart from del6q (n=1), none were of commonly known aberrations in hematological malignancies. Only 1 patient with kidney disease underwent renal biopsy that revealed light-chain deposition disease. Amyloidosis was detected in 2 patients, one with neuropathy and the other patient was asymptomatic. The MYD88 L265P mutation was detected in 10 of 14 patients (71%) tested, and CXCR4 mutations in 2 of 8 patients (25%) tested. Both patients with a CXCR4 mutation needed treatment immediately at diagnosis and subsequently had 4 or more lines of therapy. With a median follow up of 4.6 years (95% CI 2.5-7.6 years), 68% of the patients had been treated (n=21), 90% of whom within the first year from diagnosis. As such, the median time to first treatment was 2.3 months. However, time to next therapy was significantly longer, with a median of 4.7 years. Patients had a median of 3 lines of therapy (range, 1-8), including purine analogues in 33% of patients, alkylating agents in 48%, bendamustine in 38%, anti-CD20 monoclonal antibodies in 90%, proteasome inhibitor in 24%, and immunomodulating drugs in 14%. Two patients received ibrutinib: one achieved VGPR with over 3 years remission duration, after prior 7 lines of therapy; and the other, who had only a brief response, was found to carry the CXCR4 mutation. There were 4 (13%) deaths: 1 patient developed Bing-Neel syndrome at first relapse that ultimately lead to his demise; 1 died from treatment complications; and 2 of unknown cause. The 5-year and 10- year OS are 90% (95% CI 64-98%) and 81% (95% CI 49-94%), respectively (Figure 1). Conclusion: To our knowledge, this is the largest reported series of non-IgM LPL and the first to demonstrate excellent long-term outcomes in these patients. Figure 1. Figure 1. Disclosures Hunter: Pharmacyclics: Consultancy. Treon:Janssen: Consultancy, Other: Travel, Accommodations, Expenses; BMS: Research Funding; Johnson & Johnson: Consultancy; Pharmacyclics: Consultancy, Other: Travel, Accommodations, Expenses, Research Funding. Castillo:Beigene: Consultancy, Research Funding; Abbvie: Consultancy, Research Funding; Janssen: Consultancy, Research Funding; Pharmacyclics: Consultancy, Research Funding; Genentech: Consultancy; Millennium: Research Funding.

Introduction: The addition of Rituximab to chemotherapy has significantly improved the outcome of patients with newly diagnosed diffuse large B-cell lymphoma (DLBCL). Patients treated with immunochemotherapy for DLBCL who achieve EFS24 (event-free for 2 years after diagnosis) have an overall survival equivalent to that of the age- and sex-matched general population. Relapses after achieving EFS24 have been considered to be unusual but have been understudied. We sought to define the rate, clinical characteristics, treatment pattern, and outcomes of such relapses. Methods: 1448 patients with newly diagnosed DLBCL from March 2002 to June 2015 were included. Patients were enrolled in the Molecular Epidemiology Resource (MER) of the University of Iowa/Mayo Clinic Lymphoma SPORE, treated per physician choice (predominantly R-CHOP immunochemotherapy) and followed prospectively. An event was defined as progression or relapse, unplanned re-treatment after initial therapy, or death from any cause. Cumulative incidence of relapse and non-relapse mortality after achieving EFS24 were analyzed as competing events using Gray's test in the EZR software. Post-relapse survival was defined as time from relapse to death from any cause and analyzed using Kaplan-Meier method in SPSS (V22). Results: Among the 1448 patients, 1260 (87%) had DLBCL alone at diagnosis, and 188 (13%) had concurrent indolent lymphoma (follicular lymphoma 115, marginal zone lymphoma 18, chronic lymphocytic leukemia 14, lymphoplasmacytic lymphoma 4, unspecified 37) at diagnosis. After a median follow-up of 83.9 months, 896 patients achieved EFS24. For all 896 patients who achieved EFS24, the cumulative incidence of relapse (CIR) was 5.7%, 9.3% and 13.2%, respectively, at 2, 5 and 10 years after achieving EFS24. Patients with concurrent indolent lymphoma at diagnosis had a higher CIR compared to those with DLBCL alone at diagnosis (10.2 vs 4.8% at 2 years, 15.7 vs 8.0% at 5 years, 28.8 vs 9.7% at 10 years, P There were a total of 84 patients who relapsed after achieving EFS24. The median age at initial diagnosis was 66 years (range 35-92), and 48 (57%) were male. At diagnosis, 11 (13%) had ECOG PS >1, 37 (50%) had LDH elevation, 62 (74%) were stage III-IV, 14 (17%) had more than 1 extranodal site, and 26 (31%) were poor risk by R-IPI score. There were 58 patients with DLBCL alone at diagnosis who relapsed after achieving EFS24, and 38 (75%) relapsed with DLBCL, 13 (25%) relapsed with indolent lymphoma (predominantly follicular lymphoma), and pathology was unknown in 7 patients. In contrast, there were 26 patients with concurrent indolent lymphoma at diagnosis who relapsed after achieving EFS24, and 9 (41%) relapsed with DLBCL, 13 (59%) relapsed with indolent lymphoma, and pathology was unknown in 4 patients. In the 47 patients who relapsed with DLBCL after achieving EFS24, 45% received intensive salvage chemotherapy, 19% received regular intensity chemotherapy, 9% received CNS directed chemotherapy, and 36% went on to receive autologous stem cell transplant (ASCT). In the 26 patients who relapsed with indolent lymphoma after achieving EFS24, 27% were initially observed, 54% received regular intensity chemotherapy, 4% received intensive salvage chemotherapy, and 19% received ASCT after subsequent progression. The median post-relapse survival (PRS) for all patients with a relapse after achieving EFS24 was 38.0 months (95% CI 27.5-48.5). The median PRS for patients who relapsed with DLBCL and indolent lymphoma after achieving EFS24 were 29.9 (19.9-39.9) and 89.9 (NR-NR) months, respectively (P=0.002; Figure 2). Conclusions: Relapses after achieving EFS24 in patients with DLBCL were uncommon in the rituximab era. Patient with DLBCL alone at diagnosis can relapse with either DLBCL or indolent lymphoma (3:1 ratio). Patients with concurrent DLBCL and indolent lymphoma at diagnosis had a significantly higher CIR, and relapses with DLBCL and indolent lymphoma were similar (2:3 ratio). Even with high intensity salvage chemotherapy and consolidative ASCT, patients who relapsed with DLBCL had a significantly worse survival compared to those who relapsed with indolent lymphoma. Late relapses with DLBCL remain clinically challenging, with a median survival of 2.5 years after relapse. Figure 1. Figure 1. Disclosures Maurer: Celgene: Research Funding; Nanostring: Research Funding; Morphosys: Research Funding. Witzig:Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding. Ansell:Takeda: Research Funding; Pfizer: Research Funding; Affimed: Research Funding; Regeneron: Research Funding; Seattle Genetics: Research Funding; Celldex: Research Funding; LAM Therapeutics: Research Funding; Trillium: Research Funding; Merck & Co: Research Funding; Bristol-Myers Squibb: Research Funding. Cerhan:Celgene: Research Funding; Jannsen: Other: Scientific Advisory Board; Nanostring: Research Funding.

Background. Waldenström macroglobulinemia (WM) is a low-grade non-Hodgkin's lymphoplasmacytic lymphoma associated with overproduction of monoclonal IgM protein. It is preceded by an asymptomatic stage, called Smoldering Waldenström Macroglobulinemia (SWM), associated with a high risk of progression to overt disease. Current understanding of progression risk in SWM is based on a few small studies, and it is still unclear how to distinguish the asymptomatic patients who will progress from those who will not. Patients and Methods. We obtained clinical data of all WM patients who had been diagnosed and followed up at Dana-Farber Cancer Institute from 1982 to the end of 2014. Only patients with asymptomatic disease at the time of diagnosis were included in this study to identify risk factors for disease progression. Patients who received chemotherapy for a second cancer, before or after asymptomatic WM diagnosis (n =24), were excluded as chemotherapy might have affected the natural course of disease. Patients who progressed to or were diagnosed later with other types of B-cell lymphoproliferative disorders or Amyloidosis (n =71) and patients with myeloproliferative disorders or thalassemia (n = 4) were all excluded from our cohort. Furthermore, we excluded patients with no morphologic evidence of lymphoplasmacytic infiltration in the bone marrow biopsy (n =37), those without a bone marrow biopsy done at time of diagnosis (n =21), and those who were treated for peripheral neuropathy alone (n =13). Progression was defined based on the Consensus Panel recommendations of the Second International Workshop on WM. Survival analysis was performed using the Kaplan-Meier method and differences between the curves were tested by log-rank test. Effects of potential risk factors on progression rates was examined using Cox proportional-hazards models, with hazard ratios (HRs) and associated 95% confidence intervals (CIs). Results. A total of 439 patients were included in the study. During the 35-year study period and a median follow up of 7.8 years, 317 patients (72.2%) progressed to symptomatic WM. The median time to progression was 3.9 (95% CI 3.2-4.6) years. In the multivariate analysis, IgM ≥ 4,500 mg/dL (adjusted HR 4.65; 95% CI 2.52-8.58; p < 0.001), BM lymphoplasmacytic infiltration ≥ 70% (adjusted HR 2.56; 95% CI 1.69-3.87; p < 0.001), β2-microglobulin ≥ 4.0 mg/dL (adjusted HR 2.31; 95% CI 1.19-4.49; p = 0.014), and albumin < 3.5 g/dL (adjusted HR 2.78; 95% CI 1.52-5.09; p = 0.001) were all identified as independent predictors of disease progression, suggesting those thresholds could be clinically useful for determining high-risk patients. On the other hand, given the continuous nature of these variables, we built a proportional hazards model based on four variables (Bone marrow infiltration percentage, serum IgM, albumin, β2-microglobulin). The model divided the cohort into 3 distinct risk groups: a high-risk group with a median time to progression (TTP) of 1.9 years (95% CI 1.64-2.13), an intermediate-risk group with median TTP of 4.6 years (95% CI 4.31-5.15), and a low-risk group with a median TTP of 8.1 years (95% CI 7.33-8.13)(See Figure). To enhance its clinical applicability, we made the model available as user interface through a webpage and mobile application, where clinicians can enter an individual SWM patient's lab values and get information regarding their risk group and estimated individual risk of progression to symptomatic WM. Conclusion. We have assembled the largest cohort of SWM patients to date, which allowed us to identify four independent predictors of progression to overt disease: BM infiltration ≥ 70%, IgM ≥ 4,500 mg/dL, b2m ≥ 4.0 mg/dL and albumin < 3.5 g/dL. Using those variables in a proportional hazards model, we developed a robust, flexible classification system based on risk of progression to symptomatic WM. This system stratifies SWM patients into low-, intermediate- and high-risk groups and thus has the potential to inform patient monitoring and care. Most importantly, it can help identify high-risk patients who might benefit from early intervention in this rare malignancy. Figure 1. Figure 1. Disclosures Bustoros: Dava Oncology: Honoraria. Kastritis:Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Prothena: Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees. Soiffer:Jazz Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees. Treon:Johnson & Johnson: Consultancy; Janssen: Consultancy, Other: Travel, Accommodations, Expenses; BMS: Research Funding; Pharmacyclics: Consultancy, Other: Travel, Accommodations, Expenses, Research Funding. Castillo:Genentech: Consultancy; Millennium: Research Funding; Abbvie: Consultancy, Research Funding; Janssen: Consultancy, Research Funding; Beigene: Consultancy, Research Funding; Pharmacyclics: Consultancy, Research Funding. Dimopoulos:Amgen: Honoraria; Janssen: Honoraria; Takeda: Honoraria; Celgene: Honoraria; Bristol-Myers Squibb: Honoraria. Ghobrial:BMS: Consultancy; Janssen: Consultancy; Takeda: Consultancy; Celgene: Consultancy.

Background Waldenström's macroglobulinemia (WM) is a rare B-cell neoplasm defined as lymphoplasmacytic lymphoma with bone marrow infiltration and monoclonal IgM in the serum. More than 90% of WM patients carry a point mutation L265P in the MYD88 gene and concurrently, almost one third of MYD88L265P-positive patients harbor frameshift (WHIM-FS) or non-sense (WHIM-NS) mutation in gene CXCR4. The mutations in CXCR4 result in premature stop codons and in shortening of CXCR4 protein product. Incomplete C-terminal domain of CXCR4 chemokine receptor is known to hyperactivate CXCR4-mediated signalization. The presence and type of mutation in genes MYD88 and CXCR4 appears to be significant in diagnostics and prognostic stratification of WM patients and it also influences the clinical manifestation of the disease. Aims To analyze mutational status of MYD88 and CXCR4 genes in patients with WM, to compare our results with laboratory parameters and to evaluate the prognostic stratification of the patients according to MYD88 and CXCR4 mutational status. Methods Analyzed DNA was isolated from mononuclear fraction of bone marrow or peripheral blood cells at the time of diagnosis. Mutational status of analyzed genes was determined using allele-specific PCR (in the case of MYD88) and using direct Sanger sequencing (in the case of CXCR4). All found mutations were confirmed by specific cleavage with restriction endonucleases at defined conditions. Results We analyzed 23 patients with WM. All patients were MYD88L265P-positive (100 %), and 7 of them (30,4%) were also CXCR4 mutants (1 patient harbored WHIM-FS mutation and 6 harbored WHIM-NS mutation). CXCR4 mutations were associated with more aggressive disease: higher ISSWM score (low 0/intermediate 1/ high 6 risk), anemia (7/7), hyperviscosity syndrome (2/7) at time of diagnosis. CXCR4WHIM-WT patients were often asymptomatic (5/16) with lower ISSWM score (low 5/intermediate 5/ high 6 risk) but with common adenopathy (11/16). CXCR4 mutations were also associated with worse treatment response (2 CXCR4WHIM-MUT patients were refractory to initial therapy and needed 2nd line treatment, 3 patients had only partial response to first-line therapy, one patient died after 2nd cycle due to abdominal septic complication and only one patient reached VGPR). Progression-free survival in treated patients was 32 vs. 8 months in CXCR4 mutants. Conclusion/summary The mutational analysis of MYD88 and CXCR4 genes is essential for the diagnostics and prognostic stratification of patients with WM and it allows a deeper understanding of the molecular pathogenesis of the diseases. CXCR4 mutations were found in nearly one third of WM patients. In accordance with published data, we confirmed that CXCR4 mutations are associated with more aggressive disease presentation and thus affect treatment outcome. On the contrary CXCR4WHIM-WT patients have more indolent course of the disease. This work was supported by grant IGA-LF-2018-004 and MH CR - RVO (FNOL, 00098892). Disclosures No relevant conflicts of interest to declare.

Bakground. The association of light chain (AL) amyloidosis with lymphoplasmacytic lymphoma/Waldenström's Macroglobulinemia is well established. However, both localized and systemic AL amyloidosis have been also reported in other types of lymphoma, but a detailed description of these cases is still lacking. Methods. We systematically searched the database of 1,415 newly diagnosed consecutive patients (pts) with AL amyloidosis of the Pavia Amyloidosis Research and Treatment Center for pts with non-lymphoplasmacytic lymphoma and AL amyloidosis, and identified 34 pts diagnosed between 2004 and 2018. Results. Seventeen pts (50%) had a diagnosis of marginal zone lymphoma (MZL), mainly extranodal MZL (EMZL). Median age at the time of lymphoma diagnosis was 65 years (45-81) and 23 pts (68%) were males. An autoimmune disease was documented in 8 pts (24%), with Sjögren Syndrome as the commonest type. Clinical characteristics of pts according to type of lymphoma (MZL vs non-MZL) and type of AL (systemic vs localized) are presented in Tables 1 and 2. The amyloid deposits were characterized as AL-type by immunoelectron microscopy or mass spectrometry in all cases. Twelve pts (35%) had a concomitant diagnosis of AL (within 12 months before or after the diagnosis of lymphoma). In 2 cases the diagnosis of lymphoma occurred after 16 and 45 months from diagnosis of AL, respectively. In 20 pts (10 MZLs), the lymphoma was diagnosed a median time of 58.6 months (range: 13.6-320.8 months) before AL diagnosis: all but 1 of these cases were treated for the underlying lymphoma and 16 of them had a complete remission at the time of AL diagnosis. Twenty-nine pts (85%) had positive serum and/or urine immunofixation and/or an abnormal free light chains ratio (FLCR), while 5 pts had no detectable monoclonal component (MC) and normal FLCR: these pts developed only localized AL amyloidosis. Localized AL was documented in 10 pts (29%), 7 of them had a MZL. Involved organs were represented by MALT sites (6 nodular pulmonary, 1 tracheobronchial, 2 skin, 1 bladder). Eleven pts with systemic AL amyloidosis died for progression of amyloidosis and 1 because of gastric cancer, while no patient with localized AL died during follow-up. The median overall survival (OS) from the diagnosis of AL amyloidosis was 42.5 months (Fig.1). Conclusions. In our series collected in a referral center, MZL is the most common non-lymphoplasmacytic lymphoma that associates with AL amyloidosis. Hematologists should be aware that MZL is associated not only with localized light chain deposition at the lymphoma site, but also with systemic AL amyloidosis. Systemic AL amyloidosis could be itself an indication to start a specific treatment for the lymphoproliferative disease, even in otherwise asymptomatic lymphomas. The presence of a MC and elevated FLC are clues for systemic AL amyloidosis. Figure 1. Figure 1. Disclosures Merlini: Prothena: Consultancy; Janssen: Consultancy; Ionis: Consultancy; Millenium: Consultancy; Akcea: Consultancy; Pfizer: Consultancy. Palladini:Janssen: Membership on an entity's Board of Directors or advisory committees; Celgene: Other: Travel support; Prothena: Honoraria.

Introduction and aims:Bing Neel syndrome (BNS) is a rare complication of Waldenström Macroglobulinaemia (WM)/ Lymphoplasmacytic Lymphoma (LPL). It is a clinicopathological entity characterised by central nervous system involvement with malignant cells. It presents with diverse symptoms and can be difficult to recognise. However, it is a treatable condition amenable to systemic and intrathecal treatment. We present the Australasian experience of this rare entity. Methods:Inclusion in the study was based on cytologically or histologically confirmed presence of lymphoplasmacytic cells in the CSF or brain biopsy. Ten patients were included from 9 sites in Australia and New Zealand. Relevant retrospective data was extracted after obtaining consent from patients or next of kin. Results: Seven of the 10 patients were males with overall mean age of 63.5 years (range: 49-78 years); 4 patients were < 60 years old. Four patients (40%) did not have a prior diagnosis of WM; the remaining 6 patients were diagnosed ~ 11 years post diagnosis of WM (range: 3 -26 years) and received 1 line of treatment (except for 2 patients who received 2 lines of treatment). Treatment regimens received included R-CVP, chlorambucil-prednisolone, DRC, FCR, oral fludarabine, and RFM. At diagnosis of BNS, IgM and/or PP levels ranged between 3 - 70 g/L with 6 (60%) patients having levels < 10 g/L. One patient had a diagnosis of lymphoplasmacytic lymphoma with IgG paraprotein. Symptoms at presentation of BNS varied from headache, ptosis/ophthalmoplegia, memory loss, subacute hemiplegia, cognitive defects, hearing loss, and sensory or motor neuropathy. None of the patients had B symptoms. Lymphadenopathy was noted in 4 (40%) cases, splenomegaly in 1 (10%) and ECOG performance status ranged from 0-4 with 3 (30%) patients having an ECOG of > 2. Brain +/- spine MRI was done in all cases with 5 (50%) showing leptomeningeal involvement. Orbital infiltration or enhancement of optic or ophthalmic nerves was noted in 3 cases (30%), and 3 patients (30%) had focal signs/masses. 1 had cortical atrophy, and 3 had normal MRI. CSF analysis was abnormal in all cases on cytology with demonstration of abnormal lymphocytes. Where immunophenotyping was performed, it showed presence of CD5, CD10 negative B cells. MYD88 L265P was detected in 3 patients (30%). Treatment of BNS included systemic chemoimmunotherapy in 30%, CNS penetrating intravenous agents in 40%, Ibrutinib in 50%, intrathecal chemotherapy in 30%, and radiotherapy in 10%. More than 1 modality of treatment was used in 40% of patients. Ibrutinib was administered as frontline treatment in combination with high dose MTX or IT chemotherapy in 3 patients, and as single agent monotherapy in 1 patient. Ibrutinib was used as second line treatment in 2 patients with both achieving CR. The number of cycles administered were 2.6 (range 1-9). Response data was available in 9 patients with ORR in 6 (1 CR, 5 PR) and non-response in 3. All patients except the one treated with Ibrutinib monotherapy had at least PR. With a median follow-up time of 20 months, 3 patients have died. The median overall survival of patients was not reached. The 1-year and 3-year OS rates were 80% (95% CI 41-95%) and 60% (16-87%), respectively (Figure 1). Conclusion:BNS should be suspected in WM patients who develop focal or nonspecific neurological symptoms. It can be readily diagnosed on radiological scans i.e. brain and spinal MRI, and/or on CSF analysis. It can be treated with a number of systemic and intrathecal drugs including Ibrutinib, which crosses the blood brain barrier. Fig 1 legend:Kaplan Meir curve demonstrating median overall survival of patients (not reached) and 1-year and 3-year OS rates of 80% (95% CI 41-95%) and 60% (16-87%), respectively. Disclosures Talaulikar: Takeda: Research Funding; Novartis: Honoraria, Speakers Bureau; Amgen: Consultancy, Honoraria; Janssen: Honoraria, Speakers Bureau; Roche: Honoraria, Speakers Bureau. Ho:Celgene: Other: Travel to meeting ; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel to meeting; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees. Simpson:Roche: Honoraria, Research Funding; Pharmacyclics LLC, an AbbVie Company: Research Funding; Acerta: Research Funding; Merck: Honoraria, Research Funding; BeiGene: Research Funding; Sanofi: Research Funding; Bristol-Myers Squibb: Other: TRAVEL, ACCOMMODATIONS, EXPENSES; Celgene: Honoraria, Other: TRAVEL, ACCOMMODATIONS, EXPENSES; Novartis: Other: TRAVEL, ACCOMMODATIONS, EXPENSES; MSD: Honoraria; Abbvie: Honoraria, Research Funding; Amgen: Research Funding, TRAVEL, ACCOMMODATIONS, EXPENSES; Janssen: Honoraria, Research Funding. Tam:AbbVie: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; Beigene: Honoraria. Castillo:Pharmacyclics: Consultancy, Research Funding; Millennium: Research Funding; Janssen: Consultancy, Research Funding; Genentech: Consultancy; Beigene: Consultancy, Research Funding; Abbvie: Consultancy, Research Funding.

Familial clustering of the precursor condition, monoclonal gammopathy of undetermined significance (MGUS) has been observed in case reports and in smaller studies. Using population-based data from Sweden, we identified 4458 MGUS patients, 17505 population-based controls, and first-degree relatives of patients (n = 14621) and controls (n = 58387) with the aim to assess risk of MGUS and lymphoproliferative malignancies among first-degree relatives of MGUS patients. Compared with relatives of controls, relatives of MGUS patients had increased risk of MGUS (relative risk [RR] = 2.8; 1.4-5.6), multiple myeloma (MM; RR = 2.9; 1.9-4.3), lymphoplasmacytic lymphoma/Waldenström macroglobulinemia (LPL/WM; RR = 4.0; 1.5-11), and chronic lymphocytic leukemia (CLL; RR = 2.0; 1.2-2.3). Relatives of patients with IgG/IgA MGUS had a 4.0-fold (1.7-9.2), 2.9-fold (1.7-4.9), and 20-fold (2.3-170) elevated risk of developing MGUS, MM, and LPL/WM, respectively. Relatives of IgM MGUS patients had 5.0-fold (1.1-23) increased CLL risk and nonsignificant excess MM and LPL/WM risks. The results were very similar when we assessed risk by type of first-degree relative, age at MGUS (above/below 65 years), or sex. Risk of non-Hodgkin lymphoma or Hodgkin lymphoma was not increased among MGUS relatives. Among first-degree relatives of a nationwide MGUS cohort, we found elevated risks of MGUS, MM, LPL/WM, and CLL, supporting a role for germline susceptibility genes, shared environmental influences, or an interaction between both.

To the editor: Waldenstrom macroglobulinemia (WM) is a chronic lymphoproliferative disorder (LP) characterized by an immunoglobulin M monoclonal gammopathy in the presence of lymphoplasmacytic lymphoma (LPL) in the bone marrow.[1][1] We have previously shown in a large population-based study that

Immunoproliferative small intestinal disease (IPSID) was recently added to the growing list of infectious pathogen-associated human lymphomas. Molecular and immunohistochemical studies demonstrated an association with Campylobacter jejuni. IPSID is a variant of the B-cell lymphoma of mucosa-associated lymphoid tissue (MALT), which involves mainly the proximal small intestine resulting in malabsorption, diarrhea, and abdominal pain. Geographically, IPSID is most prevalent in the Middle East and Africa. IPSID lymphomas reveal excessive plasma cell differentiation and produce truncated α heavy chain proteins lacking the light chains as well as the first constant domain. The corresponding mRNA lacks the variable heavy chain (VH) and the constant heavy chain 1 (CH1) sequences and contains deletions as well as insertions of unknown origin. The encoding gene sequence reveals a deletion of V region and parts of CH1 domain. Cytogenetic studies demonstrated clonal rearrangements involving predominantly the heavy and light chain genes, including t(9;14) translocation involving the PAX5 gene. Early-stage IPSID responds to antibiotics (30%-70% complete remission). Most untreated IPSID patients progress to lymphoplasmacytic and immunoblastic lymphoma invading the intestinal wall and mesenteric lymph nodes, and may metastasize to a distant organ. IPSID lymphoma shares clinical, morphologic, and molecular features with MALT lymphoma, lymphoplasmacytic lymphoma, and plasma cell neoplasms.

[Figure][1] Bone marrow core biopsy performed in a 74-year-old man with untreated lymphoplasmacytic lymphoma showed persistent lymphoma and a large area of loosely aggregated adipose cells containing multiple cytoplasmic vacuoles, suggestive of brown adipocytes (panels A and B; hematoxylin

Introduction : Histologic transformation (HT) to an aggressive non-Hodgkin lymphoma is a well-described event in the natural history of patients with indolent lymphomas, mainly follicular lymphomas and chronic lymphocytic leukemia/small lymphocytic lymphoma. HT has been reported also in lymphoplasmacytic lymphoma (LPL)/Waldenström macroglobulinemia (WM) but only case reports or small patients series are available. Material and methods : We retrospectively searched the databases of 14 French and Belgian centers for patients with sequential or simultaneous diagnosis of LPL/WM and diffuse large B-cell lymphoma (DLBCL). Fifty-six patients (39 men and 17 women) were analyzed of whom 8 had simultaneous diagnosis of LPL/WM and DLBCL. At the time of diagnosis of LPL/WM, the median age was 65 years (range, 33-85 years). Thirty-one percent of patients presented lymphadenopathy and 27% splenomegaly. The median level of serum monoclonal IgM was 17.7 g/L (range, 2.3-66.7 g/L). The IPSSWM was available for 32 patients : 12 (38%) were low, 13 (40%) were intermediate and 7 (22%) were high-risk. At time of HT, 3 patients were previously untreated for WM. The median number of therapies for WM was 2 (range, 0-5), including chlorambucil (60%) and fludarabine-based regimens (48%). Only half of the patients were exposed to rituximab. The median time from LPL/WM diagnosis to HT for patients with sequential diagnosis (n = 48) was 59 months (range, 4-300 months). At time of transformation, 32 patients (57%) presented altered ECOG performance status (≥ 2) and B symptoms were found in about half of the patients. Tumor mass higher than 5 cm and extranodal involvement were found in 54% and 95% of patients respectively. The median serum IgM level was 6.7 g/L (range, 0-40 g/L). Serum lactate deshydrogenase levels were elevated in 72% of cases. Histology was mainly represented by DLBCL, with only 2 cases described as B-cell lymphoma, intermediate between DLBCL and Burkitt lymphoma. In situ hybridization for EBER was negative in 17 of 18 informative cases. The median number of lines of therapy given for HT was 1 (range, 0-5). First-line treatment for HT consisted of CHOP-like regimen +/- rituximab in 47 patients (85%). Five patients (9%) received DHAP association and 3 (5%) GEMOX due to cerebral involvement and/or previous CHOP-exposure. Rituximab was part of the first-line treatment for HT in 49 patients (89%). Six patients underwent autologous stem cell transplantation (SCT) and 3 allogeneic SCT. The overall response rate after first-line treatment for HT was 55% (complete response, 45%) and the median progression-free survival and overall survival after HT were 18 and 25 months respectively. The majority of deaths were attributed to disease progression (75%) or infections (18%). Conclusion : HT appears to be a critical event in the clinical course of patients with LPL/WM, associated with poor outcome. Risk factors for developing DLBCL and molecular pathogenesis of transformation in patients with LPL/WM remain to be studied. Disclosures Dupuis: janssen: Honoraria; ABBVIE: Membership on an entity's Board of Directors or advisory committees. Leblond:Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees; BMS: Honoraria; Roche: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Gilead: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau.

Background: Lymphoplasmacytic Lymphoma/Waldenströmmacroglobulinemia (LPL/WM) is a rare B-cell proliferative malignancy characterized by immunoglobulin M monoclonal gammopathy and /or bone marrow infiltration by lymphocyte, lymphoplasmacytic and/or plasma cells. The clinical features and prognosis of WM/LPL have less been investigated in Chinese patients. Moreover, few studies had reported the prognostic value of cytogenetic aberrations in Chinese WM/LPL patients. Methods: We systematically reviewed the records of 233 LPL/WM patients, who had been diagnosed at institute of Hematology&Blood Disease Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College. Results: The median age of 233 patients was 62 years (range 32-87) and the male to female ratio was 2.76 (171/62). The most common symptoms at diagnosis were fatigue (59.1%) and bleeding (11.2%). The patients in low, intermediate and higher risk group of the international prognostic scoring system for WM (ISSWM) occupied 14.9%, 32.6% and 52.6%, respectively. 90.4% and 16% patients showed an elevated serum β2-microglobulinand LDH. The percentages of hepatomegaly, splenomegaly, peripheral lymphadenopathy, B symptom were 14.9%, 34.5%, 43% and 29.3%, respectively. The degree of splenomegaly was always mild or moderate, only 19.1% patients with giant spleen. The karyotypes abnormalities were not common in LPL/WM patients. Only 8.9% (14/157) patients had abnormal chromosome karyotypes. The most common cytogenetic aberration detected by fluorescence in situ hybridization (FISH) were deletion of 17q13 (9/120, 7.5%), trisomy 12(5/58, 8.6%). Other aberrations include 13q14 deletion in 3 of 128 patients (2.3%), 11q22 deletion in2 of 90 patients (2.2%). Univariate analysis showed that age>62 years, leukocytopenia, thrombocytopenia, anemia, cytopenias ≥ 2, elevated LDH, abnormal chromosome karyotypes, P53 deletion and high risk of ISSWM were adverse risk factors for OS. But only clinical effect not reaching partial response (p=0.006), elevated LDH (p=0.049) and leukocytopenia (p=0.048) were the independent prognostic factors at multivariate analysis. Conclusion: Distinct characteristics exist in WM in China compared with the Western country. Elevated LDH and leukocytopenia were the independent adviser factors for OS in this series patient. Disclosures No relevant conflicts of interest to declare.

Introduction. Advances in treatment have improved prognosis after diagnosis with non-Hodgkin lymphoma (NHL) and chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL). Understanding factors that impact long-term morbidity and mortality of lymphoma survivors is therefore of increasing clinical importance. Elevated risk for developing cutaneous melanoma after lymphoma is well-established, but the potential extension of this association for rarer NHL subtypes and other types of cutaneous malignancies is unknown. Methods. We identified a cohort of 129,850 non-HIV infected adults (age ³20 years) who were initially diagnosed with one of the seven most common types of lymphoma (Table 1) during 2000-2013 and who survived ³1 year, as reported to 17 United States population-based cancer registries from the Surveillance, Epidemiology, and End Results program. Standardized incidence ratios (SIRs) and corresponding 95% confidence intervals (95% CI) quantified risks for second primary melanoma, Merkel cell carcinoma, and sebaceous carcinoma, comparing the observed number of cases to that expected in the general population based on age-, race-, sex- and calendar period-specific incidence rates. Results. Melanoma occurred in 258 survivors of CLL/SLL, nearly two-fold more often than expected in the general population (SIR=1.94, 95% CI=1.71-2.20). Risk also was significantly elevated among survivors of follicular lymphoma (N=108, SIR=1.32, 95% CI=1.08-1.32) and peripheral T-cell lymphoma (N=22, SIR=1.68, 95% CI=1.05-2.54), whereas SIRs were non-significantly greater than unity after other NHL subtypes except marginal zone lymphoma (N=37, SIR=1.06, 95% CI=0.74-1.46). Merkel cell carcinoma and sebaceous carcinomas were much rarer but were associated with substantially higher risks compared with melanoma. Merkel cell carcinoma also occurred most commonly after CLL/SLL (N=20, SIR=3.90, 95%CI=2.38-6.02) with significantly elevated SIRs after follicular lymphoma (N=8, SIR=2.99, 95%CI=1.29-5.89) and mantle cell lymphoma (N=7, SIR=16.04, 95% CI=6.45-33.04). In contrast, the risk patterns differed for sebaceous carcinoma, with elevated risks after CLL/SLL (N=10, SIR=5.04, 95% CI=2.42-9.27), DLBCL (N=7, SIR=5.13, 95% CI=2.06-10.57), marginal zone lymphoma (N=4, SIR=7.67, 95% CI=2.09-19.63), and lymphoplasmacytic lymphoma/Waldenstršm macroglobulinemia (N=3, SIR=14.15, 95% CI=2.92-41.35). Conclusions. Survivors of specific lymphoma subtypes have differential risks of developing a range of subsequent cutaneous malignancies. CLL/SLL is the lymphoma subtype most closely associated with cutaneous malignancy risk, whereas DLBCL survivors only have strongly elevated risk for sebaceous carcinoma. Further studies should investigate potential roles for immune dysfunction, infection, and genetic susceptibility in the etiology of cutaneous malignancies developing after NHL. Survivors and clinicians should consider the importance of regular full skin examinations to maximize opportunities for early detection of cutaneous malignancies to reduce morbidity. Disclosures No relevant conflicts of interest to declare.

Background: Population level survival has improved for myeloma in the early 21st century, but it is unknown whether a similar improvement has occurred in other plasma cell or lymphoplasmacytoid conditions. Methods: Data were extracted from 12 population-based cancer registries in Germany and the Surveillance, Epidemiology, and End Results database in the United States (US). Cases of Waldenström macroglobulinemia (WM), lymphoplasmacytic lymphoma (LPL), and plasmacytoma diagnosed in 1998-2012 were included. Myeloma survival was analyzed for comparison. Plasma cell leukemia was not included due to case numbers being too small to produce reliable estimates. Period analysis was used to determine 5-year relative survival for patients with the above malignancies in 2003-12. Trends in survival in the early 21st century were analyzed using modeled period analysis, comparing survival for 2003-07 to 2008-12. Results: In Germany, 5-year age adjusted relative survival in 2003-12 was 72.1% overall and 56.5% for patients with plasmacytoma, 74.9% for LPL not otherwise specified and 80.8% for WM. In the US, survival was higher overall at 75.1%, with survival for individual entities of 81.9% for WM, 77.2% for LPL, and 62.3% for plasmacytoma. Five year relative survival estimates for myeloma in 2003-12 were 45.2% and 43.1% in Germany and the US, respectively. Trend analysis for the years 2003-07 and 2008-12 revealed an increase in survival overall in Germany and the US, with survival for all malignancies going from 69.2% to 74.2% in Germany and 73.3% to 76.8% in the US (see table). A small, borderline significant increase in survival was observed for WM in Germany, with survival going from 74.8% to 84.3% (p=0.05) and a significant increase was observed for LPL, going from 71.7% to 77.4% (p=0.01). A pattern of small increases in survival was observed for plasmacytoma in Germany and each individual malignancy in the US. A strong and significant increase was observed in both countries for myeloma, with 5-year survival going from 41.4% to 47.9% in Germany and 38.8% to 47.0% in the US (p Conclusions: Five year survival for patients with plasma cell and plasmacytoid conditions other than myeloma varies depending on the morphology. Some evidence of increased survival was observed in rare plasma cell and plasmacytoid malignancies, but small case numbers make determination of statistical significance difficult and magnitude of the differences are less than for myeloma in most cases, with the exceptions of WM in Germany. Increased research focusing specifically on rare plasma cell malignancies and implementation of findings into cancer care may improve survival further. Table Trends in 5-year relative survival for 2003-07 to 2008-12 for rare plasma cell and plasmacytoid malignancies, with comparison to myeloma. Table. Trends in 5-year relative survival for 2003-07 to 2008-12 for rare plasma cell and plasmacytoid malignancies, with comparison to myeloma. Disclosures Pulte: EBSCO: Other: Review of content for Dynamed medical reference product; Selexys Pharmaceuticals: Research Funding; ApoPharma: Research Funding.

Introduction: MYD88 (Myeloid Differentiation Primary Response 88) mutations are the most common genetic aberration in Waldenström's macroglobulinemia/lymphoplasmacytic lymphoma (LPL). Since the initial description of MYD88 mutations in LPL, the detection has gained great importance in diagnosing the disease. However, in some patients with other B cell malignancies, including chronic lymphocytic leukemia (CLL), MYD88 mutations are detectable. Aim: We describe the molecular and cytogenetic profile of MYD88 mutated LPL in comparison to CLL, in order to identify aberration patterns potentially useful for diagnostic purposes. Patients and Methods: We analyzed bone marrow samples of 78 LPL patients for MYD88 by highly sensitive allele specific PCR (ASP) for the L265P mutation and by next-generation sequencing (NGS) for MYD88 and CXCR4 (Chemokine (C-X-C Motif) Receptor 4) mutations. For CLL, 784 blood or bone marrow samples were sequenced for MYD88 (by NGS), IGHV, TP53, NOTCH1 and SF3B1 by Sanger or NGS as well as the MYD88 mutated CLL cases for CXCR4. For all samples, cytogenetic and multiparameter flow cytometry data was available. Results: In LPL, 68/78 patients (87%) harbored a MYD88 mutation. In 13 cases with low bone marrow infiltration (median: 3%; range: 1-6%), the MYD88 mutation was detected by ASP only and not by NGS. However, one case was identified by NGS only because of a non-L265P mutation, which cannot be detected by ASP (1/68; 1%). In contrast, in CLL only 17/784 (2%) carried a MYD88 mutation. Interestingly, 5/17 (29%) were non-L265P mutations. Of the MYD88 mutated LPL, 17/68 (25%) carried a genetic lesion in the C-terminal domain of CXCR4. In contrast to MYD88, the mutation spectrum of CXCR4 was much broader including non-sense mutations at amino acid S338 (10/18) but also frame shifts resulting in loss of regulatory serine residues. One patient had two independent CXCR4 mutations (S338* and S341Pfs*25). The mean bone marrow infiltration by flow cytometry was 14% and 9% in the CXCR4 mutated and unmuted subsets, respectively (p=0.17). Besides molecular genetic aberrations, 25% (17/68) of MYD88 mutated LPL cases carried cytogenetic aberration. The most frequent cytogenetic aberration in the MYD88 positive LPL was the deletion of 6q (10/68; 15%). Other recurrent cytogenetic abnormalities were gains of 4q (n=3), 8q (n=2), and 12q (n=4), as well as loss of 11q (n=4), 13q (n=2) and 17p (n=3). In the MYD88 unmutated group, we did neither identify any CXCR4 mutation nor any del(6q), suggesting different genetic driver events in this LPL subcohort. Importantly, in the MYD88 positive CLL cohort, cytogenetic analysis did not reveal any patient with del(6q). Instead, del(13q)(q14) was the most prevalent cytogenetic aberration (12/17; 71%). Neither 11q deletions nor 17p deletions were detected. All MYD88 positive CLL had a mutated IGHV status (MYD88 unmutated CLL: 453/767; 59%; P Conclusion: Besides multiparameter flow cytometry, MYD88 mutations are the most powerful tool in the diagnosis of LPL. MYD88 mutated LPL are characterized by a high frequency of CXCR4 mutations and del(6q), while MYD88 unmutated LPLs are associated with a different pattern of genetic abnormalities. MYD88 mutated CLL is a distinct CLL subset associated with mutated IGHV status, a high frequency of 13q deletions and low frequencies of 11q and 17p deletions. MYD88 mutated CLL differs from MYD88 mutated LPL with respect to the pattern of MYD88 mutations, cytogenetic aberrations and the absence of CXCR4 mutations. Highly sensitive ASP allows the L265P mutation detection even in LPL cases with very low bone marrow infiltration; whereas highly sensitive NGS assay are best applicable for detection of more heterogenic MYD88 mutations in CLL or CXCR mutations in LPL. Thus, an integrated molecular and cytogenetic approach allows the characterization of disease specific genetic patterns and should be analyzed for its clinical impact. Disclosures Baer: MLL Munich Leukemia Laboratory: Employment. Dicker:MLL Munich Leukemia Laboratory: Employment. Kern:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Haferlach:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Haferlach:MLL Munich Leukemia Laboratory: Employment, Equity Ownership.

Background. Recently, the somatic MYD88L265P mutation has been found as the hallmark of Waldenström Macroglobulinemia (WM), being detectable in nearly 90% of cases, as well as in up to 50% of IgM MGUS, rarely in other non-Hodgkin lymphomas and never in multiple myeloma (MM). Beyond its potential diagnostic role, this mutation has been associated with tumor growth and therapy resistance. Moreover, MYD88L265P might represent an ideal marker for minimal residual disease (MRD) monitoring in a disease whose therapeutic scenario has been rapidly changing, with many new available and highly effective drugs (nucleoside analogues, proteasome and BTK-inhibitors). However, the current MYD88L265P allele-specific quantitative PCR (ASqPCR) diagnostic tool lacks sensitivity (1.00E-03) and thus is not suitable for MRD. Moreover, is not useful to test peripheral blood (PB), that harbors low concentrations of circulating tumor cells (especially after immunochemotherapy), neither to assess cell-free DNA (cfDNA), usually present at very low amount in plasma. Therefore, our study aims: 1) to assess whether a highly sensitive tool as droplet digital PCR (ddPCR) might be helpful in MYD88L265P screening; 2) to evaluate whether MYD88L265P might be a suitable marker for MRD monitoring in WM. Methods. Bone marrow (BM) and PB samples were collected at diagnosis and during follow-up from a local series of patients affected by WM, IgM MGUS and IgG-secreting lymphoplasmacytic lymphoma (LPL), as well as samples from healthy subjects and MM were used as negative controls. Genomic (gDNA) and cell-free DNA (cfDNA) were extracted as recommended (Qiagen). MYD88L265P was assessed on 100 ng of gDNA by ASqPCR as previously described [Xu 2013] and by ddPCR, using a custom dual labelled probe assay (Bio-Rad). When available, 50 ng of cfDNA were tested for MYD88L265P, only by ddPCR. ddPCR was performed on 20 µl of reaction at 55°C for 40 cycles, run on QX100 droplet reader and analyzed by QuantaSoft v1.6.6 (Bio-Rad). MYD88L265P ASqPCR level was estimated as described [Treon 2012]. ΔCT Results. Once the ddPCR assay was optimized, the sensitivity of MYD88L265P ddPCR was compared to ASqPCR on a ten-fold serial dilution standard curves built with a 70% MYD88L265P mutated WM sample, previously identified by Sanger sequencing [Treon 2012]. Whereas ASqPCR confirmed the reported sensitivity of 1.00E−03, ddPCR reached a sensitivity of 5.00E−05. Thereafter, overall 105 samples (48 BM, 57 PB, 52 diagnosis and 53 follow up) from 58 patients (49 WM, 5 IgM MGUS and 4 LPL) as well as 20 controls (15 healthy subjects and 5 MM) were tested by both methods. 32/33 (97%) diagnostic BM scored positive for MYD88L265P by both ddPCR and ASqPCR (being the only one negative a WM), while ddPCR, was able to detect more mutated cases, than ASqPCR, among diagnostic PB samples: 15/19 (79%) vs 9/19 (47%) (Table1). Moreover, to investigate whether the MYD88L265P ddPCR tool could be used for MRD detection we compared it to the standardized IGH-based MRD. An IGH-based MRD marker was found in 40/53 (75%) patients (37 WM and 3 LPL). Five Patients, so far analyzed, with baseline and follow up samples (18 BM, 5 PB) showed highly superimposable results between the two methods. Finally, pivotal results on cfDNA from 10 patients showed higher median levels of MYD88L265P mutation in plasma if compared to PB. Conclusions. We developed a new tool for diagnosis and MRD monitoring in WM, showing that: 1) ddPCR is a highly sensitive tool for MYD88L265P detection, especially useful in low infiltrated samples, like PB; 2) MYD88L265P can be effectively and easily used for MRD monitoring in WM, achieving similar results to standardized IGH-based MRD; 3) cfDNA recovered from plasma might be an attractive alternative for MYD88L265P detection, deserving further investigation. Methodological validation against IgH-based MRD detection and Flow cytometry and correlations with clinical impact are currently ongoing on external samples series. Table 1.PATIENTSWM (45)LPL (2)IgM MGUS (5)TISSUEBMPBBMPBBMPBSAMPLES31141114MYD88L265P ddPCR/ASqPCR30/3011/71/10/01/14/2 TABLE 1. MYD88L265P mutation detection in diagnostic samples: ddPCR vs ASqPCR Disclosures Boccadoro: Sanofi: Consultancy, Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees; Onyx Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees; Janssen-Cilag: Consultancy, Membership on an entity's Board of Directors or advisory committees.

Introduction: Non- Hodgkins lymphomas (NHL) are a heterogeneous group of clonal malignant diseases arising from the lymphoid system with many subtypes showing both biological and clinical heterogeneity. However, the diagnosis and treatment outcomes of NHL in resource poor countries still remain a challenge in the absence of routine immunohistochemistry and molecular studies. In Ghana, a low middle-income West African country, there has been no previous systematic study of the distribution of the major subtypes of NHL. Methods: A retrospective review of case folders of all patients age 13 years and above, diagnosed with NHL between January 1, 2008 and October 31, 2013, at Korle Bu Teaching Hospital (KBTH), Accra, the largest hospital in Ghana, and one of only two hospitals in the country with a cancer unit. Information obtained from the case folders included age, sex, histological subtype, subtypes using the Working Formulation and WHO classifications. Treatment given and follow up information were also evaluated. Results: A total of 279 cases of NHL were identified within the study period. The mean overall age of the patients was 48.8 ± 17.0 years with a minimum age of 13 years and maximum 87 years. There were 156 males (55.7 %) and 123 females (43.9 %) with a male to female ratio of approximately 1.5:1. The majority of cases seen (53%) were diffuse large B-cell lymphoma. Chronic lymphocytic leukaemia/small lymphocytic lymphoma (22.2%) was the next commonest subtype. Other sub types seen, in order of frequency, included diffuse mixed cell lymphoma (6.4%), gastric lymphomas (3.9%), mediastinal B-cell lymphoma (2.9%), Burkitts lymphoma (1.8%), splenic marginal zone B-cell lymphoma (1.1%), lymphoblastic lymphoma (1.1%), mucosa-associated lymphoid tissue (MALT) type B- cell lymphoma (0.7%) and follicular lymphoma (0.7%). Others, which included anaplastic large cell lymphoma, mantle cell lymphoma, lymphoplasmacytic lymphoma and mycosis fungoides, collectively accounted for 3.6% of the NHL cases reviewed. Based on the Working Formulation classification with broad histologic categories of low-, intermediate-, and high-grade lymphomas, 83 out of 279 (29.7%) had low grade NHL, 170 (60.7%) intermediate and 26(9.4%) had aggressive/high grade NHL. Table 1 shows chemotherapy regimens administered and first year treatment outcomes. One-year survival for cases of NHL in the study was found to be high (98.6%). However, only 115/279(41.2%) of patients were seen for follow up in the second year post-treatment, with 85 of these (73.9%) still in clinical remission. In the third year only 37/279(13.3%) reported for follow up. Conclusions: This study provides a baseline overview of the distribution of NHL subtypes and their outcomes in adolescent and adult patients in a resource constrained setting. Patient loss to follow up in the 2nd and 3rd year post treatment was very high and the reasons for this should be explored in a future study. Immunohistochemistry, cytogenetics and specific molecular studies, which are important in characterization of NHL, should be made affordable and accessible in low-income countries. Table 1. FIRST YEAR OUTCOME FOR ALL NHL SUBTYPES AND TREATMENT GIVEN TYPE OF CHEMOTHERAPY GIVEN CHOP CVP R-CHOP CHLORAMBUCIL + PREDNISOLONE CODOX-M/ IVAC TOTAL INDOLENT TYPE NHL CR 37 34 2 2 0 75 (26.9%) PR 3 1 0 0 0 4 (1.4%) NR 1 0 0 0 0 1 (0.4%) LTF 2 0 0 0 0 2 (0.7%) TOTAL 43 (15.5%) 35 (12.5%) 2 (0.7%) 2 (0.7%) 0 (0.0%) 82(29.4%) INTERMEDIATE TYPE NHL CR 120 3 9 0 0 132 (47.3%) PR 32 4 0 0 0 36 (12.9%) NR 1 0 0 0 0 1 (0.4%) LTF 2 0 0 0 0 2 (0.7%) TOTAL 155 (55.6%) 7 (2.5%) 9 (3.2%) 0 (0.0%) 0 (0.0%) 171 (61.3%) AGGRESSIVE TYPE NHL CR 9 0 3 0 1 13 (4.65%) PR 12 0 0 0 1 13 (4.65%) NR 0 0 0 0 0 0 (0.0%) LTF 0 0 0 0 0 0 (0.0%) TOTAL 21 (7.5%) 0 (0.0%) 3 (1.1%) 0 (0.0%) 2 (0.7%) 26 (9.3%) GRAND TOTAL 219 (78.5%) 42 (15.1%) 14 (5.0%) 2 (0.7%) 2 (0.7%) 279 (100%) CR: CLINICAL REMISSION, PR: POOR RESPONSE, NR: NO RESPONSE, LTF: LOST TO FOLLOW-UP Disclosures No relevant conflicts of interest to declare.

Cytogenetic analysis is invaluable for the detection of chromosome abnormalities in tumor samples and is the "gold standard" technique (unique in providing a complete overview of the chromosome complement). Cytogenetic studies of lymph node specimens (LN) can be challenging due to progressively smaller biopsies being procured, low viability, and low proliferative rates. Typically, the initial laboratory evaluation of LN includes flow cytometry and/or immunohistochemistry. Due to overlapping immunophenotypic and morphologic features of some lymphomas, these studies can be insufficient to properly classify a lymphoid neoplasm. Interphase FISH is the test most frequently utilized for LN genetic evaluation. Although FISH has higher sensitivity than conventional cytogenetics, there is vast literature on the existence of cytogenetic abnormalities that are not targeted by the FISH probe(s) used in most laboratories. This is predominantly true for CLL/SLL, but it is also seen in other lymphomas, particularly those characterized by variant translocations involving closely related genes, such as mantle cell lymphoma with alternate translocations involving the CCND2 or CCND3 genes, or lymphomas carrying MYC rearrangements where the partner is not IGH (translocation partners other than Ig genes might merit less aggressive therapy). To achieve the same information obtained from an abnormal karyotype, it is usually necessary to perform multiple FISH tests with significantly increased costs. Genomic microarray and sequencing also have limitations. Microarray can only detect DNA unbalances (missing the balanced translocations that characterize most lymphomas). These whole genomic tests cannot detect multiple related clones indicative of clonal evolution, or unrelated clonal populations indicative of distinct lymphoid neoplasms in the same specimen. Successful cytogenetics offers the best visual representation of the whole chromosome complement and often yields information making it unnecessary to perform additional genetic tests. It should be noted that alternative genetic tests are extremely useful for cases with normal chromosome results or those that lack metaphase cells for analysis, as well as those with cytogenetically cryptic rearrangements or mutations. Recent studies indicate that complex karyotypes in lymphomas are, in general, indicative of transformation and/or worse prognosis. In the present study, for example, several follicular lymphoma cases displayed other abnormalities in addition to the typical t(14;18), some of which are known to be associated with transformation, i.e., deletions 1p, 6q, and 10q. We present our experience with 362 LN received over a 15 month period during 2014 and 2015. See Table below. Through correlation with all diagnostic test results from our laboratory, we demonstrate the unique value of cytogenetic evaluation of lymphoid tissues, optimizing diagnostic/prognostic assessment and, thereby, improving patient management/therapeutic decisions, while achieving cost reduction. Table. A) Summary of cases and subdivision based on successful cytogenetics and normal or abnormal flow/morphology versus normal or abnormal cytogenetics; B) Detailed information on the number of the various lymphoid neoplasms included in our study. Total Cases: 362 No metaphases: 67 (19%) With metaphases: 295 (81%) Normal flow/morphology and normal cytogenetics 74 (25%) Abnormal flow and/or morphology 221 (75%) Normal cytogenetics: 59 (27%) Abnormal Cytogenetics: 162 (73%) Table. Final Diagnosis (Abnormal cytogenetic cases) # cases Sex (M/F) # FISH FISH Abnormal/normal FL 56 25/31 43 43/0 SLL/CLL 32 20/12 21 20/1 HGL 14 7/7 0 0 TCL 14 7/7 5 3/2 MZBCL 13 8/5 8 5/3 DH/THL 10 6/4 10 10/0 DLBCL 8 4/4 8 7/1 MCL 7 4/3 5 4/1 CD30+ 2 0/2 2 1/1 NGCL 2 0/2 2 1/1 BL 1 1/0 1 1/0 LPL 1 1/0 0 0 B-ALL/LBL 1 0/1 1 1/0 HL 1 1/0 1 1/0 Totals 162 84/78 107 (66%) 97/10 Abbreviations: FL, follicular lymphoma; SLL/CLL, small lymphocytic lymphoma/chronic lymphocytic leukemia; HGL, high-grade lymphoma; TCL, T-cell lymphoma; MZBCL, marginal zone B-cell lymphoma; DH/THL, double hit/triple-hit lymphoma; DLBCL, diffuse large B-cell lymphoma; MCL, mantle cell lymphoma,; CD30+, CD30-positive large B-cell lymphoma; NGCL, non-germinal center lymphoma; BL, Burkitt lymphoma; LPL, lymphoplasmacytic lymphoma; B-ALL/LBL, B-cell acute lymphoblastic leukemia/lymphoblastic lymphoma; HL, Hodgkin lymphoma. Disclosures No relevant conflicts of interest to declare.

Background: The regression of hepatitis C virus (HCV)-associated lymphoma with antiviral treatment (AT) is the strongest argument in favour of an etiological link between lymphoma, especially marginal zone lymphoma (MZL), and HCV infection. In addition, the favourable impact of AT on overall survival of these patients has been reported (Arcaini 2014, Michot 2015). Although there is a clear association across the studies between the lymphoma regression and the clearance of HCV, the direct anti-lymphoma activity of interferon (IFN) cannot be ruled out. AT is undergoing a revolution: new antiviral drugs, including direct-acting antiviral (DAA) like sofosbuvir (SOF) cure more than 90% of infections. However, data on new IFN-free regimens in HCV-associated lymphoproliferative disorders are scanty and based on clinical reports (Rossotti 2015; Sultanik 2015; Carrier 2015). Patients and Methods: We analyzed virological and hematological response of 26 patients (pts) with indolent B-cell non-Hodgkin lymphomas (NHL) or chronic lymphocytic leukemia (CLL) and HCV infection treated with an IFN-free AT. We included the 5 cases reported in literature (Rossotti 2015; Sultanik 2015; Carrier 2015) with updated follow up. Results: Histological, virological and hematological features are summarized in Table 1. Histology distribution was as follows: 12 splenic MZL, 6 extranodal MZL of MALT, 2 leukemic MZL, 2 nodal MZL, 2 CLL/SLL, 1 lymphoplasmacytic lymphoma (LPL) and 1 low grade NHL NOS. Cryoglobulins were present in 13 (symptomatic cryoglobulinemia in 5). HCV genotype was 1 in 15 pts, 2 in 4 pts, 3 in 3 pts and 4 in 2 pts, NA in 2 pts. Three pts previously received chemotherapy and 4 underwent IFN-based therapy before. Twenty-four pts received a SOF-based regimens (SOF + simeprevir in 10, SOF + ribavirin in 5, SOF + daclatasvir in 8, SOF + ledipasvir in 1) and 2 pts other regimens (ombitasvir + paritaprevir + ritonavir + ribavirin and faldaprevir + deleobuvir + ribavirin). In one pt with renal MZL 4 rituximab (R) doses have been added to SOF + simeprevir. Median AT duration was 12 weeks (range: 6-24). At time of present analysis, virological response is available in 21 pts while hematological response has been assessed in 20 pts. A sustained virological response has been obtained in 20 pts; hematological response has been observed only in pts with HCV clearance: in particular 8 pts (all MZL) achieved a complete response and 4 (all MZL) a partial response (comprising one treated also with R) while 5 had stable disease (response by histology is summarized in Table 1). In 7 pts response duration is +1 mo (in 2 pts), +2 mo (in 1 pt), +6 mo (in 3 pts), and +22 mo (in 1 pt); 6 pts (60%) cleared cryoglobulins after AT. After a median follow-up of 6 mo (range: 1-28), 2 pts progressed: one pt shifted to DLBCL and one pt without virological response progressed and died of lymphoma; another pt with hematological CR died of metastatic hepatocellular carcinoma 8 mo after AT. Complete data for all pts will be presented at the meeting. Conclusions: Our study shows that a significant rate of hematological response can be achieved in HCV-associated MZL also with IFN-free AT. These data are a strong rationale for planning prospective trials with DAA in this setting. Table 1. Features of 26 pts with NHL associated with HCV infection treated with IFN-free regimen and lymphoma response by histology N % Age, median (range) 26 57 (40-78) M/F 11/15 42/58 - Marginal-zone lymphoma SplenicNodalExtranodal of MALTLeukemic MZL- CLL - Lymphoplasmacytic lymphoma - Low-grade B-cell NHL NOS 22 12 2 6 2 2 1 1 84.7 46.2 7.7 23.1 7.7 7.7 3.8 3.8 Ann Arbor stage III-IV 19 73 B symptoms 4 15 ECOG 0 1 2 3 11 10 0 1 50 45 0 5 BM involvement 14 54 Extranodal disease 17 65 Splenic involvement 13 50 Liver involvement 5 19 Nodal disease 15 58 Bulky disease 7 27 Leukemic disease 9 35 Elevated LDH 8/22 36 Elevated b2-microglobulin 8/10 80 Albumin Disclosures No relevant conflicts of interest to declare.

Leukemic B-cell chronic lymphoproliferative disorders (B-CLPD) encompass a heterogeneous group of defined disease entities. However, around 10% of the cases cannot be reliably classified based on the current criteria and are considered B-CLPD not otherwise specified (B-CLPD NOS). Few recurrent mutations and genetic alterations have been reported in some entities, but none is specific. We performed gene expression profiling (GEP) to develop a robust GEP-molecular classifier for leukemic B-CLPD. We analyzed purified blood of 189 B-CLPD, including 54 chronic lymphocytic leukemia (CLL), 54 mantle cell lymphoma (MCL), 12 follicular lymphoma (FL), 23 splenic marginal zone lymphoma (SMZL), 4 splenic diffuse red pulp lymphoma (SDRPL), 4 hairy cell leukemia (HCL), 4 HCL-variant (HCL-v), 6 lymphoplasmacytic lymphoma (LPL) and 28 B-CLPD NOS. We used a multiple step approach to build a GEP-array classifier and then analyzed an additional series as a validation cohort by quantitative PCR (qPCR). Mutational analysis of BRAF, MAP2K1, MYD88, NOTCH1, NOTCH2, SF3B1 and TP53 and copy number alterations were studied. In the training set, a supervised analysis clustering revealed that each B-CLPD entity has a specific expression profile. By a multi-step GEP classifier using 43 genes ( Table 1 ) we could classify CLL, SOX11-positive MCL (MCLc), HCL, FL, SOX11-negative MCL (MCLi) and HCL-v cases in six successive stages. However, we were not able to clearly identify distinct signatures for LPL, SMZL and SDRPL. Furthermore, we could classify 36% of B-CLPD NOS cases. Interestingly, the 43-gene signature identified in leukemic samples could also classify the 28 tumor splenic biopsies. Finally, we built a simple 8-gene predictive model using qPCR data ( including: FMOD, KSR2, SOX11, MYOF, MME, CCND1, CXCR4, and CAMSAP2 ) that was used in an independent validation cohort and classified 14% B-CLPD NOS cases. The classification yield increased to 61% and 50%, for GEP-array and qPCR, respectively, when additional morphological, molecular and genetic features were considered. Our findings support the use in a routine base of a simple test as a diagnostic tool that can be applied to help multiparameter interpretation in the classification of leukemic B-CLPD and specially B-CLPD NOS. | Step model | B-CLPD | Specific signatures | | ---------- | ----------------------------------- | ------------------------------------------------------------------------------------------------------------------ | | 1 | CLL | FMOD, KSR2 , ADTRP, CLNK, LEF1, FILIP1L, CTLA4, IGSF3, EBF1 | | 2 | MCLc | SOX11 , PLEKHG4B, HDGFRP3, CNN3, PON2, SH3BP4, FCGBP, STMN1, FARP1, DBN1, NREP, NINL, MARCKSL1, MEX3D, CRIM1, KAZN | | 3 | HCL | HPGDS, IL1R2, TJP1, PLOD2, EMP1, NOVA1 | | 4 | FL | MME , SLC2A5, SMAD1, PRDM15 | | 5 | MCLi | CCND1 | | 6 | HCL-v | TUSC1, LRP1B, KCNJ3, NRCAM, MS4A14, FAM129C, CXCR4 | | 7 | Miscellaneous LPL-SDRPL-SMZL | No specific genes | Table 1. Gene signatures (43 genes) and steps used for the GEP-array model. CLL: chronic lymphocytic leukemia; FL: follicular lymphoma, HCL: hairy cell leukemia; HCL-v: hairy cell leukemia variant; LPL, lymphoplasmacytic lymphoma; MCLc: conventional SOX11-positive mantle cell lymphoma; MCLi: indolent SOX11-negative mantle cell lymphoma; SDRPL, splenic diffuse red pulp lymphoma; SMZL, splenic marginal zone lymphoma. Bold letters indicate some of the genes included in the simple qPCR model. Disclosures Lopez-Guillermo: Roche, Celgene, Mundipharma, Gilead, Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding.

Background: Waldenström's macroglobulinemia (WM) is an incurable B-cell lymphoplasmacytic lymphoma. B-cell maturation antigen (BCMA) serves as one of the receptors for B-cell activating factor (BAFF) or a proliferation-inducing ligand (APRIL), which are members of the tumor necrosis factor (TNF) family that can induce activation of NF-κB and promote survival of B cells, including neoplastic B cells. We previously showed that serum BCMA levels are elevated in multiple myeloma (MM) patients, and correlated with disease status and overall survival (OS). In this study, we sought to determine whether BCMA levels are elevated in the serum of WM patients, track with conventional WM tumor markers, and correlate with disease status and OS. Methods: Data was obtained on a total of 67 WM patients who received treatment in one of two clinics that specialize in the treatment of WM. Serum BCMA levels were determined with a polyclonal anti-BCMA antibody using an ELISA (R&D Systems, Minneapolis, MN). Mann-Whitney analysis was used to measure differences in serum BCMA levels between WM patients and healthy subjects as well as the clinical status of WM patients. Using Kaplan-Meier analysis, OS (median follow up 5.1 years) in WM patients was measured from the time of the first assessment of serum BCMA levels in each patient. In addition, serum BCMA levels were compared to serum M-protein and IgM levels in 12 patients, serially, during their individual courses of treatment. Results: We compared serum BCMA levels for all 67 patients, including 27 untreated WM patients to healthy subjects (n = 76). Serum BCMA levels were markedly elevated in all WM patients (median 79.53 ng/mL), including those who were untreated (median 82.72 ng/mL) versus healthy subjects (median 6.32 ng/mL, p < 0.0001 for both comparisons). Serum BCMA values were compared to both serum M-protein and IgM levels in 12 WM patients during their disease course. Serum BCMA levels consistently correlated with changes in both of these established WM serum markers during their course of disease. Serum BCMA levels of WM patients also correlated with patient disease status at the time of sample collection. Specifically, serum from patients achieving > partial response (PR, n = 12) showed significantly lower levels of BCMA than samples from patients with either stable disease (SD, n = 8, p = 0.030) or progressive disease (PD, n = 21, p = 0.0004). OS (median 12.5 years) was determined among patients in the highest serum BCMA quartile (n=16; quartile range 128.91-812.48 ng/mL) and compared to levels in the lower three quartiles (n = 48; range 20.13-128.85 ng/mL). Notably, OS was shorter among patients in the top quartile compared to those in the other three quartiles (p = 0.02). Conclusions: This is the first study to demonstrate that serum BCMA levels are elevated in Waldenström's macroglobulinemia patients. Importantly, serum BCMA levels correlated with both serum IgM and M-protein levels, as well as tracked with these established WM biomarkers for individual patients during their course of disease. Additionally, patients with levels of BCMA in the highest quartile exhibited shorter OS. Thus, serum BCMA represents a new serum biomarker to predict outcome and monitor patients with Waldenström's macroglobulinemia. Disclosures No relevant conflicts of interest to declare.

Background: B-cell chronic lymphoproliferative disorders (B-CLPD) comprise several entities with similar clinical manifestations, within which chronic lymphocytic leukemia (CLL) account for the majority, others including follicular lymphoma (FL), hairy cell leukemia (HCL), splenic marginal zone lymphoma (SMZL),nodal marginal zone lymphoma (NMZL), gastric mucosa-associated lymphoid tissue (MALT) lymphoma, lymphoplasmacytic lymphoma/Waldenström's macroglobulinemia (LPL/WM), and other unclassified subtypes. Cytogenetic aberrations are now the main prognostic predicators in CLL, with deletion of TP53 or ATM as the adverse predicators, while sole deletion of 13q14 as the favorable one, trisomy 12 and IGH translocation as the neutral factors. The prognostic role of this cytogenetic aberrations panel has not been well established in other B-CLPD excluding CLL. Patients and methods: A panel of DNA probes were used to detect cytogenetic aberrations by fluorescence in situ hybridization (FISH), including RB1/D13S25 at 13q14, ATM at 11q22, TP 53 at 17p13, CEP12 and IGH translocation at 14q32. Totally, 870 patients were enrolled in this study, including 459 CLL patients, 41 SMZL patients, 24 HCL patients, 96 LPL/WM patients, 24 NMZL patients with bone marrows involvement (BMI) ,59 FL patients with BMI and 161 patients without definite subtype classification. Results: The incidence of each cytogenetic aberration in CLL is as follow: 38.0%(169/445) for del 13q14, 11.5% (46/400) for del 11q22, 14.5% (66/455) for del 17p13 , 23.8% (68/286) for +12, and 21.9% (97/443) for t(14q32). While in other B-CLPD excluding CLL is as follow: 10.3% (36/351) for del 13q14, 3.6% (11/305) for del 11q22, 7.9% (30/380) for del 17p13, 12.3% (23/ 187) for +12 and 24.1% (93/386) for t(14q32). The incidence of del 13q14 (p=.000), del 11q22 (p=.000), del17p13 (p=.003) and +12 (p=.002) were higher in CLL than in other B-CLPD. With a median follow-up of 46.0 months (2.0-288.0) in CLL and 39 months (3.0-239.0) in other B-CLPD, the median estimated progress-free survival (PFS) and overall survival (OS) in CLL were 80.0 months (95% CI 67.2-92.7) and 129 months (95% CI 111.5-146.5) respectively, while in other B-CLPD were 84 months (95% CI 71.8-96.1) and 135 months respectively. In CLL, the del 13q (p=.046), del 11q (p=.002) and del 17p (p In other B-CLPD except CLL, the del 13q, del 17p and t (14q32) had no impact on both PFS (p=.983, p=.910 and p=.675 respectively) and OS (p=.171, p=.401 and p=.453 respectively). But patients with trisomy 12 had poor PFS (69.0 vs.86.0months, p=.094) and OS (69.0 vs.135.0months, p=.006) compared with those without. Del 11q also adversely impacted the OS (75.0 months vs. not reached, p=.059) but not PFS (62.0 vs. 84.0 months, p=.735). Conclusions: Del 11q and del 17p had the adverse prognostic impact in CLL. However, trisomy 12 was the predictor of poor survival in other B-CLPD which indicated neutral prognostic role in CLL. These results may imply different role of the same cytogenetic aberration in the pathology between CLL and other B-CLPD. Disclosures No relevant conflicts of interest to declare.

CD52 is expressed on malignant cells in lymphoplasmacytic lymphoma (LPL), including IgM-secreting Waldenström macroglobulinemia (WM). We examined the activity of alemtuzumab in 28 symptomatic LPL (27 IgM and 1 IgA) patients. The median prior number of therapies for these patients was 2 (range, 0-5) and 43% had refractory disease. Patients received alemtuzumab at 30 mg IV 3 times weekly for up to 12 weeks after test dosing, and also received hydrocortisone, acyclovir, and Bactrim or equivalent prophylaxis. Patients had a complete response (n = 1), a partial response (n = 9), or a MR (n = 11) for an overall and major response rate of 75% and 36%, respectively. Median serum Ig decreased from 3510 to 1460 mg/dL (P < .001 at best response). With a median follow-up of 64 months, the median time to progression was 14.5 months. Hematologic and infectious complications, including CMV reactivation, were more common in previously treated patients and were indirectly associated with 3 deaths. Long-term follow-up revealed late-onset autoimmune thrombocytopenia (AITP) in 4 patients at a median of 13.6 months after therapy, which contributed to 1 death. Alemtuzumab is an active therapy in patients with LPL, but short- and long-term toxicities need to be carefully weighed against other available treatment options. Late AITP is a newly recognized complication of alemtuzumab in this patient population. This study is registered at www.clinicaltrials.gov as NCT00142181.

Trabajo presentado al "13th Congress of the European Hematology Association" celebrado en Copenhague en Junio del 2008.-- et al., Limited knowledge exists about the impact of specific genetic abnormalities on the proliferation of neoplastic B cells from chronic lymphoproliferative disorders (B- CLPDs). Here we analyze the impact of cytogenetic abnormalities on the proliferation of neoplastic B cells in 432 B-CLPD patients, grouped according to diagnosis and site of sampling, versus their normal counterparts. Overall, proliferation of neoplastic B cells highly varied among the different B-CLPD subtypes, the greatest numbers of proliferating cells being identified in diffuse large B-cell lymphoma (DLBCL) and Burkitt lymphoma (BL). Compared with normal B cells, neoplastic B-CLPD cells showed significantly increased S + G2/M-phase values in mantle cell lymphoma (MCL), B-chronic lymphocytic leukemia (B-CLL), BL, and some DLBCL cases. Conversely, decreased proliferation was observed in follicular lymphoma, lymphoplasmacytic lymphoma/ Waldenstrom macroglobulinemia (LPL/ WM), and some DLBCL patients; hairy cell leukemia, splenic marginal zone, and MALT-lymphoma patients showed S + G 2/ M phase values similar to normal mature B lymphocytes from LN. Interestingly, in B-CLL and MCL significantly higher percentages of S + G 2/M cells were detected in BM versus PB and in LN versus BM and PB samples, respectively. In turn, presence of 14q32.3 gene rearrangements and DNA aneuploidy, was associated with a higher percentage of S + G2/M-phase cells among LPL/WM and B-CLL cases, respectively. © 2008 by The American Society of Hematology., This work has been partially supported by the following grants: FIS 06/0824, from the Ministerio de Sanidad y Consumo (Madrid, Spain) and RETICC RD06/0020/0035 from the Instituto de Salud Carlos III, Ministerio de Sanidad y Consumo (Madrid, Spain). S.Q. is supported by a grant from COLCIENCIAS (Bogotá, Colombia), J.M.S. is supported by a grant from the Ministerio de Sanidad y Consumo (Madrid, Spain; CP05/ 00321), A.R. is supported by a grant from the Ministerio de Ciencia y Tecnología (Madrid, Spain) y Fondo Social Europeo, and C.F. is supported by a grant from the Instituto de Salud Carlos III (Madrid, Spain; CM05/00250).

Background: Rituximab has demonstrated significant clinical efficacy in the treatment of NHL, particularly in combination with chemotherapy, and its use has dramatically changed the treatment and outcome of both indolent and aggressive B-cell NHL over the past decade. Furthermore, consistent toxicity data have been obtained with a safe and tolerable profile in a large majority of patients. Aim: The objective of this retrospective study is to evaluate the long-term efficacy of rituximab monotherapy (4 weekly infusion at induction followed by 4 infusion every 2 months as consolidation) used for patients with relapsed indolent NHL. Results: From May 1998 through January 2011, Among 919 patients with indolent NHL treated in our department, 488 (53%) relapsed and were treated with rituximab alone (first and later relapse). 126 (26%) responded and were still in response 2 years later. These 126 patients (68 (54%) males and 58 (46%) females with a median age of 61 y; range: 17-94) are the subject of our analysis. 24% were over 70 years old, 45% were in first relapsed and 25% in later relapsed. Only 16% of the population have more than one co-morbidities (cardiac and or renal respectively); 79% a normal PS (0-1) with only 4 patients having a PS >2; 80% no bulky disease but 72% a disseminated disease (73% stage III and IV). In this study, 60 (48%) patients had a follicular lymphoma with 50% at an intermediate risk group according to the FLIPI score ; 20 (16%) a marginal zone lymphoma, and 43 (34%) a small lymphocytic or lymphoplasmacytic lymphoma and 3 patients other characteristics of lymphoproliferative disorders. After rituximab monotherapy, 55% of the entire cohort was in complete response (CR) and 31% in CRu or partial response and 5% in stable disease. Among these 126 patients, 74% progressed later than 3 years (38% later than 5 years). With a median follow-up of 6.5 years, 4-year and 8-year PFS were 70% and 30%, respectively. 18% had transformation into Richter syndrome and 12 patients have died. Conclusion: Rituximab monotherapy is an effective therapy in selected relapsed indolent NHL and allows long-term response. This strategy could be used as “spare of chemotherapy” which is an important question today, especially in indolent not curable disease. Disclosures No relevant conflicts of interest to declare.

There are a number of small B-cell proliferations that do not fall into any of the types of B-cell neoplasms recognized in the WHO classification using classical immunophenotypic markers. This situation is notably encountered in the case of the differential diagnosis of marginal zone lymphoma (MZL), atypical chronic lymphocytic leukemia (aCLL) mantle cell lymphoma (MCL) or lymphoplasmacytic lymphoma (LPL). This is mostly due to the lack of immunological specific markers especially when histological samples are not available or during leukemic phases of atypical B-cell neoplasms. In order to find new markers to discriminate between these different malignancies, we have previously developed a proteomic strategy based on the analyses of plasma membrane microparticles and proposed two new specific markers: CD148 and CD1801, 2 for MCL and MZL respectively. The simultaneous use of these two markers, together with the CD200 that is positive in most cases of CLL and negative in MCL3 could be of great interest to better assess the differential diagnosis. In the present study, we report the results obtained by the combination of the three markers studied in addition to the routine flow cytometry panel: CD148 (Clone 143-41 FITC); CD180 (Clone G28.8 PE) and CD200 (Clone OX104 APC). An expression profile of these proteins have been established on a well characterized set of patients: CLL with a Matutes score > 3 (N=28); MCL harboring t(11;14) translocation or CCND1 overexpression (N=20); LPL (N=16) classified following cytological morphology, IgM peak and positivity of CD38, and MZL (N=27), displaying a CD5- CD23-immunophenotype associated to a splenomegaly. For each group the mean of fluorescence intensity and Standard Error have been determined. MCL patients exhibited a strong expression of CD148 (MFI = 1480) combined with a weak expression of CD180 and CD200 (MFI = 888 and 426 respectively). A weak expression of CD148 and CD180 (MFI = 495 and 754) coupled to a strong expression of CD200 (MFI = 3750) was typical of the CLL group and a weak expression of CD148 and CD200 (MFI = 640 and 1200) coupled to a strong expression of CD180 (MFI = 5300) was observed in the MZL group. A moderate expression of these three markers was observed in the LPL group. A threshold corresponding to MFI +/- 4 standard error was then calculated for each group (see table 1), and patients were categorized following the expression profile of these 3 markers. Table 1: threshold calculated from the average MFI and the associated standard error for each studied pathologies. CD148 CD180 CD200 MCL >980 500 MZL 2700 In this cohort, the above described profiles correctly identified MCL cases with a specificity of 96% and a sensitivity of 65%, CLL cases with a specificity of 95% and a sensitivity of 79%, LPL cases with a specificity of 95% and a sensitivity of 31% and MZL cases with a specificity of 99% and a sensitivity of 52%. These results strongly suggest that the incorporation of these three markers CD148 CD180 and CD200 in addition of the routinely used flow cytometry panel can be helpful in a number of cases for which the diagnosis remains difficult. References: 1) Miguet et al. Leukemia 2013 2) Miguet et al. Journal of Proteome Research 2009 3) Palumbo et al. Leukemia Research 2009 Disclosures No relevant conflicts of interest to declare.

CD180 is a Toll-Like Receptor homolog strongly expressed on normal human B-cells and involved in innate immune responses. Previous proteomic analyses on microparticles derived from mature B-cell neoplasms allowed us to identify CD180 as a marker of marginal zone lymphomas (MZL)(Miguet, Leukemia, 2013). Using flow cytometry on blood samples we showed that this protein is lost or underexpressed at the plasma membrane for almost all B-cell lymphomas except MZL. In order to confirm its clinical relevance, we conducted a prospective multicenter flow cytometry study in 5 French University Hospital laboratories, on behalf of the GEIL. Blood or bone marrow samples from 236 patients were studied (20 normal controls ; 74 chronic lymphocytic leukemia (CLL); 21 mantle cell lymphoma (MCL); 42 lymphoplasmacytic lymphoma (LPL); 13 follicular lymphoma (FL) ; 58 MZL, 14 of which with numerous villous lymphocytes; 8 hairy cell leukemia (HCL)). Analyses were performed either on FACSCanto II (BD Biosciences, 3 centers) or on Navios (Beckman Coulter, 2 centers) instruments. Harmonization process was performed using Rainbow beads (Spherotech). For the CLL group, CD180 Median fluorescence (MdFI) in each center was not significantly different (Anova test, p>0.05). Instruments’ harmonization was therefore effective enough to obtain similar data from all centres. In the whole cohort, CD180 was significantly less expressed in the group of lymphomas -including CLL, MCL, LPL and FL- than in controls (Mann-Whitney test, p0.05) but significantly higher than in CLL, MCL, LPL and FL (Mann-Whitney test, p These results underline the efficiency of CD180 as a single positive and robust marker for MZL diagnosis, and confirm that between centers and between instruments harmonization is largely feasible in routine practice as published recently (Solly F et al. Cytomery part A, 2013). It should be emphasized that among the group of lymphomas with intense expression of CD180, all interestingly originating from the spleen, those with numerous villous lymphocytes display the highest expression. We described for the first time in this study the strong positivity of CD180 in HCL. Anti-CD180 antibody may be included in diagnosis combination markers in order to improve the diagnosis of chronic B-cell malignancies Disclosures No relevant conflicts of interest to declare.

Background: Waldenström's macroglobulinemia (WM) and lymphoplasmacytic lymphoma (LPL) are lymphoproliferative disorders with bone marrow infiltration by clonal lymphoplasmacytic cells (Treon et al., 2003, 2005). The somatic point mutation L265P in the myeloid differentiation primary response gene 88 (MYD88) has been reported in more than 90% of WM patients (Treon et al., 2012). Therefore MYD88 mutation analysis has been implemented in clinical practice to support the diagnosis of LPL/WM. After the implementation of MYD88 L265P assays with increased detection sensitivity, a substantial portion of patients with IgM monoclonal gammopathy of undetermined significance (IgM-MGUS) was also reported MYD88 L265P positive. Splenic marginal zone lymphoma (SMZL), B-cell chronic lymphoproliferative disorders (B-CLPD) and diffused large B-cell lymphoma (DLBCL) have been found positive with much lower incidence rates (Varettoni et al., 2013; Xu et al., 2013). Hence the remaining need to differentiate WM/LPL from other lymphoproliferative disorders with co-occurring plasma cells with high confidence. Patients and Methods: In this study, flow cytometric cell sorting was utilized to isolate clonal plasma and B lymphoid cell fractions as previously described (Zehentner et al., 2011). 69 patient specimen fractions with a clinical history of WM /LPL, multiple myeloma, CLL and lymphoma were analyzed for MYD88 L265P mutation using Sanger sequencing. Furthermore, the Biomed-2 primer sets for the immunoglobulin heavy (IgH) and/or the immunoglobulin kappa light chain region (IgK) were used to compare B cell clonality profiles in the lymphoid versus plasma cell compartments. Results: MYD88 L265P mutation was detected in all specimens with confirmed Waldenström's macroglobulinemia (17/17, 100%). Of these 16/17 (94%) revealed MYD88 L265P as well as identical monoclonality profile by gene rearrangement analysis in both the plasma and the B lymphoid cell collections. In 47% (8/17), the mutation was only detected in the plasma and B cell fractions, but not in the whole bone marrow specimens. 21 patient specimens with a known clinical history of LPL and co-occurring clonal plasma cells were tested. 9 of 21 (43%) were categorized with identical B cell clonality profile when comparing plasma and B lymphoid cells; whereas 12 (57%) had unrelated clonality profiles. 7 of the 9 (78%) specimens in the identical clonality group tested positive for MYD88 L265P in both the plasma and B lymphoid clone. None of the unrelated clonality group specimens carried the mutation in both cell fractions; for 7/12 (58%) MYD88 L265P was found in either the plasma (2) or the B-cell fraction (5) whereas 5/12 (42%) tested negative. 11 bone marrow aspirate specimen with known presence of lymphoma (including splenic marginal zone (SMZL), mantle cell and marginal zone) were analyzed. 10/11 (90%) tested negative for MYD88 L265P, with the exception of one SMZL specimen. Furthermore, 12 known myeloma, 5 CLL and 3 healthy donor specimens were analyzed, all tested negative. Conclusions: In this study, we developed and tested a novel approach to assess MYD88 L265P mutation status in order to assist WM/LPL diagnosis. Flow cytometric cell sorting for clonal plasma and B cell populations was combined with molecular analysis. Subsequently, MYD88 L265P mutation as well as B-cell clonality profile was compared in both cell fractions. Our study postulates a significant improvement in sensitivity and most importantly specificity when applying MYD88 L265P mutation status in combination with cell sorting for WM/LPL diagnostic decisions. 47% WM patients (8/17) and 44% LPL patients (4/9) were positive for the MYD88 mutation exclusively in both flow cytometry sorted cell fractions but not in whole bone marrow specimens. 94% (16/17) WM as well as 78% (7/9) LPL specimens with identical plasma and B-cell clonality profile revealed the presence of the MYD88 L265P mutation in both the plasma cell and the B lymphoid cell clones. Whereas LPL specimens with unrelated clonality profile of the plasma and lymphoid cell fractions as well as other control specimens (lymphoma, myeloma, CLL and healthy) either tested negative or positive only in one of the sorted cell fractions. We therefore conclude that confirming the presence of MYD88 L265P in both B-lymphoid and plasma cell fraction is an important prerequisite to distinguish LPL/WM from related disorders with high confidence. Disclosures Wang: HematoLogics Inc.: Employment. Fritschle:HematoLogics Inc.: Employment. Bennington:HematoLogics Inc.: Employment. Burnworth:HematoLogics Inc.: Employment. Bennington:HematoLogics Inc.: Employment. Wentzel:HematoLogics Inc.: Employment. Verkamp:HematoLogics Inc.: Employment. Nguyen:HematoLogics Inc.: Employment. Ghirardelli:HematoLogics Inc.: Employment. Broderson:HematoLogics Inc.: Employment. Wells:HematoLogics Inc.: Employment, Equity Ownership. Loken:HematoLogics Inc.: Employment, Equity Ownership. Zehentner:HematoLogics Inc.: Employment, Equity Ownership.

Introduction Fluorine 18 Fluorodeoxyglucose (FDG) Positron emission tomography-computed tomography (PET-CT) scan was highly sensitive modality for evaluating the staging or response of malignant lymphoma. The role of PET to detect early relapse in complete remission was still uncertain. We evaluated the clinical implication of surveillance PET-CT scan in lymphoma patients according to histologic subtype of lymphoma. Patients and methods A total 1009 patients of 1553 treated lymphoma patients, who achieved complete response following primary treatment, were retrospectively reviewed. Among these patients, we analyzed 202 patients who showed positive results of PET-CT and performed tissue biopsy of FDG uptake sites. Results Total 202 surveillance PET-CT positive patients, 120 (59.4%) patients were confirmed lymphoma relapse, 82 (40.6%) patients were histologically negative. Histologically negative results of 82 patients as follows: most (59.7%) patients were inflammation, 10 (2.1%) patients were solid tumor and 3 patients were tuberculosis. According to histologic subtype, PPV of Hodgkin's lymphoma was 25.0% (4/16), diffuse large B-cell lymphoma patients was 51.0% (47/92), mantle cell lymphoma (MCL) was 86.6% (13/15) and extranodal NK/T cell lymphoma (ENKL) was 85.7% (12/14) (Table 1). There was significant difference between PPV of aggressive B-cell non-Hodgkin lymphoma (NHL) except MCL and aggressive T-cell NHL (51.0% vs 78.5%, P=0.040). Indolent NHL was related with high PPV compared to aggressive B-cell NHL (70.2% vs 51.0%, P=0.032). Six (12.7%) patients of 47 indolent lymphoma were transformed to DLBCL at relapse. Four (8.5%) patients of 47 DLBCL patients showed histologic change to indolent lymphoma. There was no difference of predictive value according to stage, the number of extranodal involvement, lactic dehydrogenase and international prognostic index. PPV of FDG uptake in lymph node was 58.3% (63/108) and other sites except lymph node were 60.6% (57/94). Biopsy of stomach was 53.3% (8/15), small or large bowel was 55.5% (7/12). True positive patients of core biopsy was 61 (65.5%) of 93 patients, operation or excisional biopsy was 59 (67.0%) of 88 patients and aspiration cytology was 4 (19.0%) of 21 patients. Conclusion PPV of surveillance PET-CT in aggressive B-cell lymphoma was lower than indolent lymphoma or aggressive T-cell lymphoma. Surveillance PET-CT had clinical limitations according to histologic subtype of lymphoma. Histologic confirm by re-biospy should be recommended to exclude the false positive in aggressive B-cell lymphoma and distinguish the histologic transformation in indolent lymphoma. Table 1. Positive predictive value according to lymphoma subtype Pathology Lymphoma subtype positive negative Positive predictive value DLBCL (n=92) 47 45 51.0 MZBCL (n=26) 17 9 65.3 Follicular lymphoma (n=20) 16 4 80.0 Mantle cell lymphoma (n=15) 13 2 86.6 Burkitt lymphoma (n=3) 1 2 33.3 Plasmablastic lymphoma (n=1) 1 0 100 Lymphoplasmacytic lymphoma (n=1) 0 1 0 ENKL (n=14) 12 2 85.7 PTCL (n=11) 7 4 63.6 Mycosis fungoides (n=3) 2 1 66.6 Hodgkin's lymphoma (n=16) 4 12 25.0 Total (n=202) 120 82 59.4 Disclosures No relevant conflicts of interest to declare.

Lymphoplasmacytic lymphoma and marginal zone lymphoma in the bone marrow: paratrabecular involvement as an important distinguishing feature Assia Bassarova, Gunhild Tr¿en, Signe Spetalen, Francesca Micci, Anne Tierens, Delabie Abstract Lymphoplasmacytic lymphoma (LPL) is a neoplasm of small B-lymphocytes, lymphoplasmacytoid and plasma cells involving bone marrow and sometimes lymph nodes and spleen. Lymphoplasmacytic lymphoma is often accompanied by Waldenström macroglobulinemia. Since the original description, Waldenström macroglobulinemia has become recognized as a distinct clinicopathological entity defined by serum IgM paraprotein and bone marrow involvement by lymphoplasmacytic lymphoma. Since serum IgM paraprotein in itself is not specific and can be seen in a variety of small B-cell lymphoproliferative disorders, notable chronic lymphatic leukemia and marginal zone lymphoma, as well as in rare cases of myeloma, the diagnosis of Waldenström macroglobulinemia rests largely upon the proper diagnosis of LPL in the bone marrow. The differential diagnosis between bone marrow involvement by lymphoplasmacytic lymphoma (LPL) and marginal zone lymphoma (MZL) is challenging because histology and immunophenotype of both diseases overlap. The diagnosis may be helped by demonstrating the MYD88 L265P mutation, seen in most LPL. However, the mutation is also present in MZL, although at a lower frequency. To better define the distinguishing features of LPL we studied a series of bone marrow trephine biopsies of 59 patients with Waldenström's macroglobulinemia (WM) without extramedullary involvement and compared the findings with bone marrow biopsies from 23 patients with well-characterized MZL who also had bone marrow involvement. H&E and immunoperoxidase-stained sections of bone marrow trephine biopsies as well as flow cytometry and classical cytogenetics performed on aspirations were reviewed. The study was complemented with MYD88L265P mutation analysis on the bone marrow trephine biopsies of all patients. The features are summarized in Table 1. The most distinguishing features of LPL with respect to MZL were focal paratrabecular involvement (p Table 1. Summary of the pathology features of lymphoplasmacytic and marginal zone lymphoma in bone marrow trephine biopsies Lymphoplasmacytic lymphoma Marginal zone lymphoma p Infiltration pattern* Paratrabecular Nodular non-paratrabecular Paratrabecular and non-paratrabecular Intrasinusoidal Diffuse 37% (10/27) 0% (0/27) 56% (15/27) 37% (10/27) 0% (0/27) 0% (0/16) 75% (12/16) 0% (0/16) 37% (6/16) 25% (4/16) *the analysis was only performed on bone marrow trephine biopsies showing less than 66% lymphoma infiltration In conclusion, LPL can reliably be distinguished from MZL in the bone marrow by using a combination of pathology characteristics. In contrast to other studies, our findings stress the diagnostic importance of paratrabecular infiltration in LPL. Disclosures No relevant conflicts of interest to declare.

Background: Morphological examination of bone marrow trephine biopsy represents a standard method for non-Hodgkin’s lymphomas (NHL) staging. Immunohistochemistry staining of bone marrow trephine specimens has been widely used in haematological malignancies due to its high applicability and sensitivity at diagnosis. However, the routine use of immunohistochemistry in the clinical settings when there is no obvious morphological (light microscopic) evidence of lymphoma in the bone marrow trephine, is not yet well established universally. We assessed the value of immunohistochemistry (by using a standard basic panel of anti-CD20 and anti-CD3 staining) in detecting involvement by NHL in routinely processed bone marrow trephine specimens with no obvious morphological involvement with lymphoma. Methods: This study involved 56 randomly selected paraffin wax embedded, formalin fixed bone marrow trephine specimens between February 2011 and September 2013 from three teaching hospitals in Northeast, UK. 49 patients (87%) had B-cell NHL: diffuse large B cell lymphoma (DLBCL) 43% (n=24), follicular lymphoma (FL) 18% (n=10), marginal zone lymphoma (MZL) 9% (n=5), mantle cell lymphoma (MCL) 7% (n=4), lymphoplasmacytic lymphoma (LPL) 6% (n=3) and Burkitt’s lymphoma (BL) 6% (n=3). 7 cases (12%) had T/NK lymphomas. There was no obvious morphological evidence of bone marrow infiltration as all samples were reviewed by two examiners. All specimens were stained with the anti-CD20 and anti-CD3 antibodies. Results: Concordant results were found in 50 samples (89%), as both investigations were reported negative. 6 of the 56 cases (11%) with no morphological evidence of involvement by NHL on routine stains, were positive on immunohistochemistry. Considering histology, discrepant results were noted more frequently in T/NK lymphomas (42%; 3 of 7 cases) comparing to B-cell NHLs (6%; 2 cases of DLBCL and 1 case of FL). In all six cases the lymphoid infiltrates had diffuse pattern. Conclusions: Our results indicate that immunohistochemistry can detect a subgroup of NHL patients with bone marrow involvement beyond discriminatory level of conventional stains (Haematoxylin & Eosin and Giemsa), thereby contributing to accuracy of staging and treatment planning. Rational application of immunohistochemistry is a cost-effective & valuable method in routine investigation of staging bone marrow trephine biopsies. Disclosures No relevant conflicts of interest to declare.