Search

The tumor microenvironment (TME) and limited immune surveillance play important roles in lymphoma pathogenesis. Here we aimed to characterize immunological profiles of diffuse large B-cell lymphoma (DLBCL) and predict the outcome in response to immunochemotherapy. We profiled the expression of 730 immune-related genes in tumor tissues of 81 patients with DLBCL utilizing the Nanostring platform, and used multiplex immunohistochemistry to characterize T-cell phenotypes, including cytotoxic T cells (CD8, Granzyme B, OX40, Ki67), T-cell immune checkpoint (CD3, CD4, CD8, PD1, TIM3, LAG3), as well as regulatory T-cells and Th1 effector cells (CD3, CD4, FOXP3, TBET) in 188 patients. We observed a high degree of heterogeneity at the transcriptome level. Correlation matrix analysis identified gene expression signatures with highly correlating genes, the main cluster containing genes for cytolytic factors, immune checkpoint molecules, T cells and macrophages, together named a TME immune cell signature. Immunophenotyping of the distinct cell subsets revealed that a high proportion of immune checkpoint positive T cells translated to unfavorable survival. Together, our results demonstrate that the immunological profile of DLBCL TME is heterogeneous and clinically meaningful. This highlights the potential impact of T-cell immune checkpoint in regulating survival and resistance to immunochemotherapy. (Registered at clinicaltrials.gov identifiers: NCT01502982 and NCT01325194.)

Background/aim The chromosome translocation t(14;21)(q11;q22) was reported in four pediatric T-cell lymphoblastic leukemias and was shown to activate the OLIG2 gene. Materials and methods A pediatric T-cell lymphoblastic lymphoma was investigated using G-banding chromosome analysis, fluorescence in situ hybridization (FISH), and immunocytochemistry. Results The malignant cells carried a t(14;21)(q11;q22) aberration. The translocation moves the enhancer elements of TRA/TRD from band 14q11 to 21q22, a few thousands kbp downstream of OLIG1 and OLIG2, resulting in the production of both OLIG1 and OLIG2 proteins. Conclusion The translocation t(14;21)(q11;q22) occurs in some pediatric T-cell lymphoblastic malignancies. Activation of both OLIG1 and OLIG2 by t(14;21)(q11;q22) in T-lymphoblasts and the ensuing deregulation of thousands of genes could explain the highly malignant disease and resistance to treatment that has characterized this small group of patients.

T cells modified to express chimeric antigen receptor (CAR) targeting CD19 (CD19CAR) have produced remarkable clinical responses in patients with relapsed/refractory B-cell acute lymphoblastic leukemia. CD19CAR T-cell therapy has also demonstrated prominent effects in B-cell non-Hodgkin lymphoma (B-NHL) patients. However, a subset of patients who relapse after CD19CAR T-cell therapy have outgrowth of CD19− tumor cells. Hence, development of alternative CARs targeting other B-cell markers represents an unmet medical need for B-cell acute lymphoblastic leukemia and B-NHL. Here, we confirmed previous data by showing that, overall, B-NHL has high expression of CD37. A second-generation CD37CAR was designed, and its efficacy in T cells was compared with that of CD19CAR. In vitro assessment of cytotoxicity and T-cell function upon coculture of the CAR T cells with different target B-cell lymphoma cell lines demonstrated comparable efficacy between the 2 CARs. In an aggressive B-cell lymphoma xenograft model, CD37CAR T cells were as potent as CD19CAR T cells in controlling tumor growth. In a second xenograft model, using U2932 lymphoma cells containing a CD19− subpopulation, CD37CAR T cells efficiently controlled tumor growth and prolonged survival, whereas CD19CAR T cells had limited effect. We further show that, unlike CD19CAR, CD37CAR was not sensitive to antigen masking. Finally, CD37CAR reactivity was restricted to B-lineage cells. Collectively, our results demonstrated that CD37CAR T cells also can effectively eradicate B-cell lymphoma tumors when CD19 antigen expression is lost and support further clinical testing for patients with relapsed/refractory B-NHL.

Checkpoint blockade can reverse T-cell exhaustion and promote antitumor responses. Although blocking the PD-1 pathway has been successful in Hodgkin lymphoma, response rates have been modest in B-cell non-Hodgkin lymphoma (NHL). Coblockade of checkpoint receptors may therefore be necessary to optimize antitumor T-cell responses. Here, characterization of coinhibitory receptor expression in intratumoral T cells from different NHL types identified TIGIT and PD-1 as frequently expressed coinhibitory receptors. Tumors from NHL patients were enriched in CD8+ and CD4+ T effector memory cells that displayed high coexpression of TIGIT and PD-1, and coexpression of these checkpoint receptors identified T cells with reduced production of IFNγ, TNFα, and IL2. The suppressed cytokine production could be improved upon in vitro culture in the absence of ligands. Whereas PD-L1 was expressed by macrophages, the TIGIT ligands CD155 and CD112 were expressed by lymphoma cells in 39% and 50% of DLBCL cases and in some mantle cell lymphoma cases, as well as by endothelium and follicular dendritic cells in all NHLs investigated. Collectively, our results show that TIGIT and PD-1 mark dysfunctional T cells and suggest that TIGIT and PD-1 coblockade should be further explored to elicit potent antitumor responses in patients with NHL.

Background: To compare the Nordic and the Memorial Sloan-Kettering Cancer Center (MSKCC) chemotherapy protocols for Overall Survival (OS) and Progression-Free Survival (PFS) for intracranial primary CNS lymphoma (PCNSL). Methods: A prospective database at Oslo University Hospital of PCNSL was reviewed over a 12-year period (2003–2014). Results: Overall, 79 patients with PCNSL were identified, of whom 57 received chemotherapy. MSKCC with Rituximab (RTX) was used in 18 patients (32%) who had median OS of 46.3 months [9.8–131.9] and median PFS of 34.6 months [6.4–131.9]. The Nordic protocol was used in 14 patients (25%) who had median OS of 30.9 months [2.7–106.3] and PFS of 14.3 months [0.0–106.3]. The MSKCC was used without RTX in 25 patients (44%) who had OS of 15.2 months [0.7–136.5] and PFS of 12.0 months [0.0–117.0]. MSKCC with RTX had a significantly longer median OS (p

Purpose: In neuroblastoma (NB), the ALK receptor tyrosine kinase can be constitutively activated through activating point mutations or genomic amplification. We studied ALK genetic alterations in high-risk (HR) patients on the HR-NBL1/SIOPEN trial to determine their frequency, correlation with clinical parameters, and prognostic impact. Materials and methods: Diagnostic tumor samples were available from 1,092 HR-NBL1/SIOPEN patients to determine ALK amplification status (n = 330), ALK mutational profile (n = 191), or both (n = 571). Results: Genomic ALK amplification (ALKa) was detected in 4.5% of cases (41 out of 901), all except one with MYCN amplification (MNA). ALKa was associated with a significantly poorer overall survival (OS) (5-year OS: ALKa [n = 41] 28% [95% CI, 15 to 42]; no-ALKa [n = 860] 51% [95% CI, 47 to 54], [P < .001]), particularly in cases with metastatic disease. ALK mutations (ALKm) were detected at a clonal level (> 20% mutated allele fraction) in 10% of cases (76 out of 762) and at a subclonal level (mutated allele fraction 0.1%-20%) in 3.9% of patients (30 out of 762), with a strong correlation between the presence of ALKm and MNA (P < .001). Among 571 cases with known ALKa and ALKm status, a statistically significant difference in OS was observed between cases with ALKa or clonal ALKm versus subclonal ALKm or no ALK alterations (5-year OS: ALKa [n = 19], 26% [95% CI, 10 to 47], clonal ALKm [n = 65] 33% [95% CI, 21 to 44], subclonal ALKm (n = 22) 48% [95% CI, 26 to 67], and no alteration [n = 465], 51% [95% CI, 46 to 55], respectively; P = .001). Importantly, in a multivariate model, involvement of more than one metastatic compartment (hazard ratio [HR], 2.87; P < .001), ALKa (HR, 2.38; P = .004), and clonal ALKm (HR, 1.77; P = .001) were independent predictors of poor outcome. Conclusion: Genetic alterations of ALK (clonal mutations and amplifications) in HR-NB are independent predictors of poorer survival. These data provide a rationale for integration of ALK inhibitors in upfront treatment of HR-NB with ALK alterations. Key Objective: High risk neuroblastoma (HR-NB) is one of the most difficult childhood cancers to cure. This study examined whether the presence of an ALK alteration (amplification or mutation) was associated with a poor prognosis in a large patient series treated on the prospective European high-risk neuroblastoma trial (HR-NBL1). Knowledge Generated: We found that ALK amplification or clonal mutation was associated with inferior prognosis in patients with HR-NB and both are independent prognostic variables on multivariate analysis. To our knowledge, this is the first study to report the highly prognostic significance of ALK amplification in HR-NB. Relevance: As ALK can be targeted therapeutically, this study convincingly argues for the introduction of ALK inhibitors for upfront management of patients with HR-NB with ALK aberrations. Importantly, the prognostic significance of ALK alterations included a subgroup of trial patients treated with the current standard of care for HR-NB including anti-GD2 immunotherapy. info:eu-repo/semantics/publishedVersion

Survival of patients with high-risk diffuse large B-cell lymphoma (DLBCL) is suboptimal, and the risk of central nervous system (CNS) progression is relatively high. We conducted a phase 2 trial in 139 patients aged 18 to 64 years who had primary DLBCL with an age-adjusted International Prognostic Index (aaIPI) score of 2 to 3 or site-specific risk factors for CNS recurrence. The goal was to assess whether a dose-dense immunochemotherapy with early systemic CNS prophylaxis improves the outcome and reduces the incidence of CNS events. Treatment consisted of 2 courses of high-dose methotrexate in combination with biweekly rituximab (R), cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP-14), followed by 4 courses of R-CHOP-14 with etoposide (R-CHOEP) and 1 course of high-dose cytarabine with R. In addition, liposomal cytarabine was administered intrathecally at courses 1, 3, and 5. Coprimary endpoints were failure-free survival and CNS progression rates. Thirty-six (26%) patients experienced treatment failure. Progression occurred in 23 (16%) patients, including three (2.2%) CNS events. At 5 years of median follow-up, failure-free survival, overall survival, and CNS progression rates were 74%, 83%, and 2.3%, respectively. Treatment reduced the risk of progression compared with our previous trial, in which systemic CNS prophylaxis was given after 6 courses of biweekly R-CHOEP (hazard ratio, 0.49; 95% CI, 0.31-0.77; P = .002) and overcame the adverse impact of an aaIPI score of 3 on survival. In addition, outcome of the patients with BCL2/MYC double-hit lymphomas was comparable to the patients without the rearrangements. The results are encouraging, with a low toxic death rate, low number of CNS events, and favorable survival rates. This trial was registered at www.clinicaltrials.gov as #NCT01325194.

Background: In precision cancer medicine, the challenge is to prioritize DNA driver events, account for resistance markers, and procure sufficient information for treatment that maintains patient safety. The MetAction project, exploring how tumor molecular vulnerabilities predict therapy response, first established the required workflow for DNA sequencing and data interpretation (2014–2015). Here, we employed it to identify molecularly matched therapy and recorded outcome in end-stage cancer (2016–2019). Material and methods: Metastatic tissue from 26 patients (16 colorectal cancer cases) was sequenced by the Oncomine assay. The study tumor boards interpreted called variants with respect to sensitivity or resistance to matched therapy and recommended single-agent or combination treatment if considered tolerable. The primary endpoint was the rate of progression-free survival 1.3-fold longer than for the most recent systemic therapy. The objective response rate and overall survival were secondary endpoints. Results: Both common and rare actionable alterations were identified. Thirteen patients were found eligible for therapy following review of tumor sensitivity and resistance variants and patient tolerability. The interventions were inhibitors of ALK/ROS1-, BRAF-, EGFR-, FGFR-, mTOR-, PARP-, or PD-1-mediated signaling for 2–3 cases each. Among 10 patients who received treatment until radiologic evaluation, 6 (46% of the eligible cases) met the primary endpoint. Four colorectal cancer patients (15% of the total study cohort) had objective response. The only serious adverse event was a transient colitis, which appeared in 1 of the 2 patients given PD-1 inhibitor with complete response. Apart from those two, overall survival was similar for patients who did and did not receive study treatment. Conclusions: The systematic MetAction approach may point forward to a refined framework for how to interpret the complexity of sensitivity versus resistance and patient safety that resides in tumor sequence data, for the possibly improved outcome of precision cancer medicine in future studies.

High-risk 11q deleted neuroblastomas typically display undifferentiated/poorly differentiated morphology. Neuroblastoma is thought to develop from Schwann cell precursors and undifferentiated neural crest (NC) derived cells. It is therefore vital to understand mechanisms involved in the block of differentiation. We identify an important role for oncogenic ALK-ERK1/2-SP1 signaling in maintenance of undifferentiated NC-derived progenitors via repression of DLG2, a tumor suppressor in neuroblastoma. DLG2 is expressed in the ‘bridge signature’ that represents the transcriptional transition state when neural crest cells or Schwann Cell Precursors become chromaffin cells of the adrenal gland. We show that restoration of DLG2 expression spontaneously drives neuroblastoma differentiation highlighting the importance of DLG2 in this process. Further, genetic analysis of high-risk 11q-deletion neuroblastomas identified genetic lesions in the DLG2 gene. Our data also suggest that further exploration of other ‘bridge genes’ may help elucidate the mechanisms underlying the differentiation of NC-derived progenitors and their contribution to neuroblastoma.

Key Points Diagnostic and relapse diffuse large B-cell lymphoma (DLBCL) biopsies reveal increased mutational burden/loss of heterozygosity in HLA-A. Serially sampled tumor biopsies provide insight into therapeutic targets and evolutionary divergence in relapsed/refractory DLBCL.

Patients with mantle cell lymphoma (MCL) generally have a dismal prognosis. Intensified induction treatment with rituximab and high dose cytarabine (R_HDAC), and consolidation with high-dose therapy with autologous stem cell support has resulted in 10-year overall survival (OS) higher than 60%. However, the clinical course varies. Diagnostic tools capable of stratifying patients include the MCL International Prognostic Index (MIPI), gene expression-based proliferation signature, Ki-67 proliferation index or tumour cell morphology. Here, we tested the performance of a newly developed Nanostring-based RNA expression-based proliferation assay (MCL35) on formalin-fixed paraffin-embedded tumour tissue from younger patients recruited in or treated according to Nordic MCL protocols compared to the prognosticators listed above. Seventy-four patients were included and the assay performed well in all cases except four, which had inadequate RNA quality. The patients were evenly distributed in the MCL35 low-, intermediate- and high-risk categories. MCL35 low- and intermediate- risk groups had overlapping progression-free survival (PFS), while patients in the high-risk category had significantly inferior PFS. Combining MCL35 with MIPI or the MIPI-C (MIPI with the addition of binary Ki67 score +/-30%) showed a better discrimination than either assessment alone. In conclusion, the MCL35 assay alone or combined with MIPI or MIPI-C scores can identify patients who still have a dismal outcome despite intensified treatment.

The purposes of this study are to study the impact of deep brain involvement on overall survival (OS) and progression-free survival (PFS) in intracranial primary CNS lymphoma (PCNSL), and to explore possible mechanisms for this impact using advanced MRI techniques. Seventy-nine patients with histologically verified PCNSL were identified from a prospective clinical database of patients treated at Oslo University Hospital between 2003 and 2014. Patients were treated per standard chemotherapeutic regimens (N = 57) or no chemotherapy (N = 22). Anatomical MRIs were available in all patients to assess tumor load and location based on contrast agent enhancement visible on T1-weighted images. Diffusion MRIs were available in 33 (42%) patients and perfusion MRI in 13 (16%) patients that received active treatment. Across all patients, OS and PFS were 16.4 and 9.8 months, respectively. In multivariate analysis, MRI-based deep brain involvement (80%) was the only negative significant factor of OS (OR = 14.2; P

Diffuse large B-cell lymphoma (DLBCL) is a heterogeneous disease. Several genetic drivers have been suggested based on gene-expression and RNA sequencing. However, clinical trials based on these molecular subclassifications have failed to improve treatment results and standard of care in DLBCL is still R-CHOP (rituximab, cyclophosphamide, doxorubicin, prednisone) based therapy, which results in approximately an 70% 5-year overall survival rate. Nordic Lymphoma Group (NLG) has conducted two large phase II trials (NLG-LBC-04; NCT 01502982 and NLG-LBC-05; NCT 01325194) during the last decade with the aim of improving the treatment outcome for young ( The aim of our study was to search for prognostic markers and possible therapeutic targets at the protein level in a uniformly treated patient cohort from the two Nordic trials (n=64) with available tumor-tissue. Thus, in this study, we investigated the protein expression pattern in the pre-therapeutic formalin-fixed paraffin embedded tumor samples by nano liquid-chromatography coupled to a mass spectrometer (Orbitrap Fusion) through an EASY-Spray nano-electrospray ion source (nLC-MS/MS). We identified 4,622 proteins with at least two unique peptides across all samples. In the combined cohort, we were able to, based on differential protein expression of 190 proteins between patients (p Disclosures Holte: Gilead: Membership on an entity's Board of Directors or advisory committees; Roche: Membership on an entity's Board of Directors or advisory committees; Nordic: Membership on an entity's Board of Directors or advisory committees; Nanovector: Membership on an entity's Board of Directors or advisory committees, Other: lectures honorarias; Novartis: Membership on an entity's Board of Directors or advisory committees; Takeda: Membership on an entity's Board of Directors or advisory committees. Jørgensen: Gilead/Kite: Consultancy; Novartis: Consultancy; Celgene/BMS: Consultancy; Roche: Consultancy.

Introduction: Plasmablastic lymphoma (PBL) is an aggressive B-cell lymphoma that predominantly occurs in patients with HIV or other causes of immunodeficiency. Frequent infection by the Epstein-Barr virus (EBV) and MYC translocations have been described as major features contributing to the pathogenesis of PBL. Prior studies examining the genetic landscape of PBL have largely relied on targeted capture-based sequencing approaches. As such, the molecular features of PBL remain to be fully explored. Here, we provide a comprehensive description of the genomic landscape of PBL using whole-genome and whole-exome sequencing to identify commonly perturbed pathways. Method: Archival diagnostic fresh frozen and formalin fixed paraffin embedded tissue biopsies from 58 PBL tumours were accrued from Lymphoma/Leukemia Molecular Profiling Project (LLMPP) sites, including 15 tumours from Ramis-Zaldivar et al., Haematolgica 2021. MYC rearrangements were identified by break-apart fluorescent in situ hybridization (FISH) and rearrangement partner was determined in a subset of tumours from capture or genome sequencing data using structural variant callers Manta, GRIDSS, and Delly. High confidence somatic mutations (SNVs/Indels) were identified in data from whole-genome (n=5) or whole-exome (n=53) sequencing through an ensemble voting approach utilizing four variant callers (Strelka2, Lofreq, Mutect2, SAGE). Mutation frequencies in known lymphoma-related genes were compared to activated B-cell (ABC)-DLBCL (Schmitz et al., NEJM 2018), as the closest tumour entity in terms of putative cell-of-origin differentiation stage, to identify differences in genetic aberrations. Candidate somatic copy number alterations (CNAs) were identified from exome and genome sequencing data, using CopywriteR and ControlFREEC, respectively, and high-confidence CNAs were determined using GISTIC2.0. Results: Within the study cohort, 81% of patients were male with a median age of 59 years (range 11-88). HIV and EBV statuses were available for 47% of patients and 95% of tumours, respectively, with 49% (13/27) of the patients being HIV+ and 69% (38/55) of tumours being EBV+. MYC rearrangement was observed in 60% (35/58) of PBLs, with IGH as the partner gene in 88% (21/24) of tumours. The most frequently mutated genes were STAT3 (38%), TP53 (22%), NRAS (21%), and TET2 (16%), consistent with previous studies, however novel mutations were seen in DUSP2 (21%), KLHL6 (16%), and BHLHE41 (16%). Recurrent CNAs included amplifications in 1q, whole gains of 7, 8q24, 11p12 and deletions affecting 4p16, 5p15, 10q11.22. While the mutational landscapes were similar between samples with and without a MYC translocation, the MYC-translocated PBLs showed more frequent amplification of 1q32.1. When stratifying by EBV status, STAT3 and SOCS1 mutations were more frequent in EBV-positive tumours, whereas TP53, TET2, KRAS, and MMRN2 mutations were associated with EBV-negativity. In comparison to ABC-DLBCL, PBLs were significantly enriched in STAT3 and NRAS mutations, and lacked common mutations affecting the NF-κB pathway (eg. MYD88, CD79B, and NFKBIZ 3' UTR mutations). Mutations in genes that are frequently mutated in ABC-DLBCLs, such as those associated with plasma cell differentiation (eg. PRDM1) or a memory B-cell fate (eg. TBL1XR1), were also not mutated in PBLs. Finally, genetic alterations associated with immune evasion, such as deletion of MHC I and II and mutations in B2M, CIITA, and CD58, were rarely observed. Conclusion: These data present a comprehensive overview of the genomic landscape of PBLs in a large cohort. We show frequent mutations involving the JAK-STAT and MAPK pathways, wherein the genetic landscape can be differentially characterized by EBV status and MYC rearrangement status. We show that PBLs are genetically distinct from ABC-DLBCLs, with absence of mutations in genes affecting the NF-κB pathway, immune evasion, and driving a memory B-cell fate. Disclosures Slack: Seagen: Consultancy, Honoraria. Raess: Scopio Labs: Research Funding. Holte: Gilead: Membership on an entity's Board of Directors or advisory committees; Roche: Membership on an entity's Board of Directors or advisory committees; Nordic: Membership on an entity's Board of Directors or advisory committees; Nanovector: Membership on an entity's Board of Directors or advisory committees, Other: lectures honorarias; Novartis: Membership on an entity's Board of Directors or advisory committees; Takeda: Membership on an entity's Board of Directors or advisory committees. Savage: Servier: Consultancy, Honoraria; Roche: Research Funding; BMS: Consultancy, Honoraria, Other: Institutional clinical trial funding; Astra-Zeneca: Consultancy, Honoraria; Merck: Consultancy, Honoraria, Other: Institutional clinical trial funding; AbbVie: Consultancy, Honoraria; Seattle Genetics: Consultancy, Honoraria; Takeda: Other: Institutional clinical trial funding; Beigene: Other: Institutional clinical trial funding; Genentech: Research Funding. Steidl: Seattle Genetics: Consultancy; Curis Inc.: Consultancy; Bayer: Consultancy; Epizyme: Research Funding; Trillium Therapeutics: Research Funding; AbbVie: Consultancy; Bristol-Myers Squibb: Research Funding. Rimsza: NanoString Technologies: Other: Fee-for-service contract. Morin: Foundation for Burkitt Lymphoma Research: Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy; Epizyme: Patents & Royalties. Scott: Abbvie: Consultancy; AstraZeneca: Consultancy; Rich/Genentech: Research Funding; BC Cancer: Patents & Royalties: Patent describing assigning DLBCL COO by gene expression profiling--licensed to NanoString Technologies. Patent describing measuring the proliferation signature in MCL using gene expression profiling. ; Incyte: Consultancy; Janssen: Consultancy, Research Funding; Celgene: Consultancy; NanoString Technologies: Patents & Royalties: Patent describing measuring the proliferation signature in MCL using gene expression profiling..

Introduction: Regulatory T cells (Tregs), a highly immunosuppressive subset of CD4 T cells, are enriched in B-cell non-Hodgkin lymphoma (NHL) and constitute a barrier to potent antitumor immune responses. Despite extensive studies, the significance of tumor-infiltrating Tregs on disease outcome is unclear and while Tregs may express co-inhibitory and co-stimulatory receptors, the role of intratumoral Tregs in the context of immune checkpoint therapy remains elusive. Emerging evidence suggests heterogeneity among Tregs and their suppressive capacities in cancer, emphasizing the need for additional markers to identify highly suppressive Tregs. Therefore, an in-depth characterization of Treg heterogeneity in NHL could provide important insight into the disease pathogenesis and have implications for rational drug design. Methods: Expression of checkpoint receptors in Tregs was characterized by fluorescence flow cytometry and mass cytometry analysis of single-cell suspensions from diffuse large B-cell lymphoma (DLBCL; n = 16), follicular lymphoma (FL; n = 8), mantle cell lymphoma (MCL; n = 10), marginal zone lymphoma (MZL; n = 2), chronic lymphocytic lymphoma (CLL; n = 7), as well as tonsils (n = 8) and peripheral blood (n = 4) from healthy donors. Functional characterization of intratumoral Tregs was performed by a proliferation assay using FACS-sorted Tregs as suppressor cells and autologous CellTrace Violet-labelled T effector cells as responder cells. Single-cell RNA sequencing (scRNA-seq) was performed on FACS-sorted CD4 T cells from 3 DLBCL, 3 FL and 3 healthy donor tonsils using the 10X Genomics single cell 5' based library construction and VDJ libraries for TCR-sequencing. Additionally, for simultaneous profiling of phenotypic features with the mRNA expression in single cells, Cellular Indexing of Transcriptomes and Epitopes by Sequencing (CITEseq) was applied. The Treg compartment was characterized by clustering into distinct transcriptional Treg states and differential expression of marker genes. Results: TIGIT and CTLA-4 were identified as common markers of intratumoral Tregs, in addition to FOXP3 and CD25. Unsupervised computational analysis revealed two distinct Treg subsets, based on contrasting expression of PD-1, OX40, CD226 and ICOS (Figure 1A). One subset displayed a checkpoint receptorlow phenotype that corresponded to peripheral blood Tregs. The second subset had a checkpoint receptorhigh phenotype with elevated levels of PD-1, OX40, ICOS, TIGIT, CTLA-4 and increased levels of activation markers CD28, CD69 and CD95/Fas. The frequency of checkpoint receptorhigh Tregs was significantly increased in NHL tumors, compared to PBMCs and tonsils from healthy donors. FL tumors had the highest frequency of Tregs with receptorhigh phenotype among the NHL entities (median frequency of 86%, range 71-92%) and DLBCL had the highest donor-to-donor variation (median frequency of 77%, range 35-98%) (Figure 1B). This phenotypic heterogeneity of the Treg compartment reflected different suppressive capacities of the two subsets. Checkpoint receptorhigh Tregs were more potent mediators of immunosuppression in terms of suppressing the proliferation of autologous effector CD4 and CD8 T cells (Figure 1C). Furthermore, transcriptomic analysis of CD4 T cells by scRNA-seq and CITEseq revealed distinct transcriptomic signatures of the checkpoint receptorhigh and -receptorlow subsets. In addition, a third subset of Tregs, characterized by increased expression of LAG3 and immunosuppression-associated genes (CTLA-4, IL10, CD38, KLRB1) but lack of FOXP3, was identified (Figure 1D-E). Analysis of scTCR-sequences to compare TCR repertoires and to identify developmental trajectories will further add to our knowledge of intratumoral Tregs. Conclusions: These results reveal heterogeneity within the Treg compartment in NHL based on expression of checkpoint receptors, transcriptional profiles and suppressive capacities. As intratumoral Treg phenotypes differ from peripheral blood Tregs, this presents new therapeutic opportunities. Specific targeting of intratumoral Tregs would lead to stronger antitumor effects while limiting immune-related adverse events. A deeper understanding of Treg heterogeneity within the tumor microenvironment could therefore open new paths for rational design of immune checkpoint therapy. Disclosures Kolstad: Merck: Research Funding; Nordic Nanovector: Membership on an entity's Board of Directors or advisory committees, Research Funding. Alizadeh:Janssen: Consultancy; Genentech: Consultancy; Pharmacyclics: Consultancy; Chugai: Consultancy; Celgene: Consultancy; Gilead: Consultancy; Roche: Consultancy; Pfizer: Research Funding.

Acquired mutations were recently described in cutaneous T-cell lymphomas for the JAK1, JAK3, STAT3, and STAT5B genes of the JAK-STAT pathway. In the present study, RNA-sequencing of a primary cutaneous CD4 positive T-cell lymphoma carrying a three-way t(9;13;16)(p24;q34;p11) chromosome translocation showed that JAK2 from chromosome band 9p24 was rearranged and fused to a novel partner gene, ATXN2L, from 16p11. RT-PCR together with Sanger sequencing verified the presence of the ATXN2L-JAK2 fusion transcript. The ATXN2L-JAK2 fusion gene would code for a chimeric protein containing all domains of ATXN2L and the catalytic domain of the JAK2 tyrosine kinase. The ATXN2L-JAK2 chimeric protein could lead to constitutive activation of the downstream JAK-STAT signaling pathway in a manner similar to that seen for other JAK2 fusion proteins.

Folliculotropic mycosis fungoides (FMF), a variant of mycosis fungoides (MF) with distinct clinical features, is characterized by infiltration of malignant T cells in hair follicles. This raises the hypothesis that antigens in the hair follicle may contribute to the pathogenesis of FMF. T-cell receptor β gene (TRB) sequences as well as dendritic cell subsets in patients with FMF (n = 21) and control patients with MF (n = 20) were studied to explore this hypothesis. A recurrent usage of the TRB junctional genes TRBJ2-1 and TRBJ2-7 was found in patients with FMF compared with those with MF. These genes contribute to an amino acid motif in the complementarity-determining region 3 (CDR3) of the T-cell receptor. This motif was previously found in T cells stimulated by lipids bound to CD1 on antigen-presenting cells. Additional immunohistochemical analysis revealed abundant CD1c- and CD1a- expressing dendritic cells in FMF. The combined findings support a role for lipid-antigen stimulation in FMF.

BACKGROUND: The current study was conducted to expedite international standardized reporting of bone marrow disease in children with neuroblastoma and to improve equivalence of care. METHODS: A multidisciplinary International Neuroblastoma Response Criteria Bone Marrow Working Group was convened by the US National Cancer Institute in January 2012 with representation from Europe, North America, and Australia. Practical transferable recommendations to standardize the reporting of bone marrow disease were developed. RESULTS: To the authors' knowledge, the current study is the first to comprehensively present consensus criteria for the collection, analysis, and reporting of the percentage area of bone marrow parenchyma occupied by tumor cells in trephine-biopsies. The quantitative analysis of neuroblastoma content in bone marrow aspirates by immunocytology and reverse transcriptase-quantitative polymerase chain reaction are revised. The inclusion of paired-like homeobox 2b (PHOX2B) for immunohistochemistry and reverse transcriptase-quantitative polymerase chain reaction is recommended. Recommendations for recording bone marrow response are provided. The authors endorse the quantitative assessment of neuroblastoma cell content in bilateral core needle biopsies-trephines and aspirates in all children with neuroblastoma, with the exception of infants, in whom the evaluation of aspirates alone is advised. It is interesting to note that 5% disease is accepted as an internationally achievable level for disease assessment. CONCLUSIONS: The quantitative assessment of neuroblastoma cells is recommended to provide data from which evidence-based numerical criteria for the reporting of bone marrow response can be realized. This is particularly important in the minimal disease setting and when neuroblastoma detection in bone marrow is intermittent, where clinical impact has yet to be validated. The wide adoption of these harmonized criteria will enhance the ability to compare outcomes from different trials and facilitate collaborative trial design.

Follicular lymphoma (FL) constitutes a significant proportion of lymphomas and shows frequent relapses. Beyond conventional chemotherapy, new therapeutic approaches have emerged, focussing on the interplay between lymphoma cells and the microenvironment. Here we report the immunophenotypic investigation of the microenvironment of a clinically well-characterized prospective cohort (study SAKK35/10, NCT01307605) of 154 treatment-naive FL patients in need of therapy, who have been treated with rituximab only or a combination of rituximab and the immunomodulatory drug lenalidomide/Revlimid® A high ratio of CD4- to CD8-positive T cells (P = 0·009) and increased amounts of PD1+ tumour-infiltrating T cells (P = 0·007) were associated with inferior progression-free survival in the whole cohort. Interestingly, the prognostic impact of PD1+ T cells and the CD4/CD8 ratio lost its significance in the subgroup treated with R2 . In the latter group, high amounts of GATA3+ T helper (Th2) equivalents were associated with better progression-free survival (P < 0·001). We identified tumour microenvironmental features that allow prognostic stratification with respect to immuno- and combined immuno- and immunomodulatory therapy. Our analysis indicates that lenalidomide may compensate the adverse prognostic implication of higher amounts of CD4+ and, particularly, PD1+ T cells and that it has favourable effects mainly in cases with higher amounts of Th2 equivalents. [Correction added on 11 February 2020, after online publication: The NCT-trial number was previously incorrect and has been updated in this version].

Most patients whose large bowel cancer has spread to other organs do not respond to immune therapy. We detected a rare gene mutation, termed 9p24.1 copy-number gain (CNG), in an otherwise incurable colorectal cancer that provoked an immune therapy response. We identified this gene mutation by gene-panel sequencing of DNA from a liver metastasis biopsy from a patient who had disease refractory to standard therapies. Following immune checkpoint blockade (ICB) with pembrolizumab (anti–PD-1), the patient experienced conversion of the tumor phenotype from one with epithelial features to that of an inflamed microenvironment, detected by high-resolution RNA sequencing. Circulating tumor DNA disappeared over the first weeks of therapy. As assessed by standard radiographic measurement, the patient had a partial response that was durable. This patient's response may support the use of histology-agnostic ICB in solid tumors that carry the rare 9p24.1 CNG.

Introduction Relapses of diffuse large B-cell lymphoma typically occur within 2-3 years and only 10% of these patients reach a 3-year progression-free survival compared to 65% at diagnosis. Our ability to distinguish patients at risk for relapse remains based on clinical staging. We hypothesized that identifying genetic alterations in serial tumour biopsies at diagnosis and relapse would improve our ability to identify high-risk patients, make therapeutic selections and reveal molecular markers for chemo-immunotherapy resistant tumours. However, relatively few relapsed/refractory biopsies have been sequenced. A unique, clinically annotated, Nordic DLBCL cohort was used to identify significantly mutated genes, assess potential driver genes, comprehensively examine clonal evolution, and gauge the importance of clinical relapsed sampling. Methods To address the lack of information on the molecular foundations of relapsed/refractory DLBCL, we performed whole exome sequencing (WES) on 42 DLBCL cases, with 34% representing relapsed/refractory biopsies and 13 serially sample cases. Enriched with relapsed/refractory diffuse large B-cell lymphoma cases, we performed multiple computational analyses to identify significantly mutated genes (MutSig2CV), mutational signatures (NMF and DeConstructsSig), driver genes (IntOgen and CADD), clonal evolution architecture (SciClone and ClonEvol), druggable gene analysis (DGIdb), and HLA-inference and mutation calling (Polysolver). Results Clonal evolution analysis of 13 paired diagnostic and relapsed biopsies revealed that relapsed/refractory biopsies have remarkable similarities to diagnostic biopsies and often present with late divergent clonal evolution of the tumor. Mutational analysis of 18 serially sampled tumors determined that in the majority of cases druggable oncogenic variants do arise at relapse. In addition, time to relapse correlated with divergence of mutations from the diagnostic biopsy. In addition to being identified as a significantly mutated gene, mutations in HLA-A had an increased incidence in cases that ultimately relapsed. This result led to an in-depth investigation into the mutational prevalence, timing, impact on prognosis, and loss of heterozygosity in the human leukocyte antigen (HLA) haplotypes of relapsed/refractory DLBCL. HLA-A mutagenesis and loss of heterozygosity was discovered as mechanisms of immune evasion in cases that go on to relapse from R-CHOP like therapies (Figure 1). Conclusions Our results yield insight into the development of chemo-immunotherapy resistant diffuse large B-cell lymphoma, and highlight the clinical importance of sampling relapsed biopsies. Analysis of immune evasion through MHC Class I/II, specifically HLA-A, may provide better characterization of patients for relapse prediction. In the age of personalized medicine it will be instrumental to determine if relapsed biopsies offer additional insight for salvage therapy treatment. Divergence of biopsies, as characterized by shared genomic mutations, increase with time and the majority of cases present with new alterations in druggable genes post-therapy. Disclosures Leppa: Roche: Consultancy, Honoraria, Research Funding; Takeda: Consultancy, Research Funding; Janssen: Consultancy, Research Funding; Celgene: Consultancy; Bayer: Research Funding. Holte:Novartis: Honoraria, Other: Advisory board.

Background: High-grade B-cell lymphoma with MYC and BCL2 and/or BCL6 rearrangements (HGBL-DH/TH) occurs in approximately 8% of de novo diffuse large B-cell lymphoma (DLBCL) cases, with BCL2 translocations (HGBL-DH/TH-BCL2) being a germinal center B-cell like (GCB) phenomenon (Scott et al. Blood 2018). HGBL-DH/TH is associated with poor outcome when treated with standard R-CHOP-therapy, but retrospective studies suggest that more aggressive treatment may improve outcome (Petrich et al. Blood 2014; Oki et al. BJH 2014). To overcome limitations with identification of HGBL-DH/TH by fluorescence in situ hybridization (FISH), Ennishi et al. developed a gene expression signature (DHITsig) that identified tumors with a HGBL-DH/TH-BCL2 gene expression phenotype. This DHITsig was translated into a new assay (DLBCL90) for application on formalin-fixed paraffin-embedded (FFPE) biopsies (Ennishi et al. J Clin Oncol 2019), and included identification of cell-of-origin (COO) and primary mediastinal B-cell lymphoma (Scott et al. Blood 2014; Mottok et al. Blood 2018). The DHITsig roughly doubled the number of cases in the HGBL-DH/TH-group compared with FISH, and was associated with a poor prognosis in patients treated with R-CHOP. In our study we aimed to validate the DLBCL90 assay in an independent cohort of young high-risk patients treated with dose-intensive immunochemotherapy within two Nordic trials. Patients and methods: RNA was extracted from pretreatment FFPE biopsies from 88 high-risk de novo DLBCL patients treated with dose-dense immunochemotherapy with systemic CNS prophylaxis in two Nordic trials (Holte et al. Ann. Oncol. 2013; Leppä et al. 15-ICML 2019). In the first trial patients received 6 courses of R-CHOEP-14 followed by 1 course of HD-Mtx and HD-Ara-C. In the second trial 2 courses of HD-Mtx were given in combination with R-CHOP-14 at the start of treatment, followed by 4 courses of R-CHOEP-14 and 1 course of R-HD-Ara-C at the end. Liposomal Ara-C was also administered intrathecally at courses 1, 3 and 5. Digital gene expression was performed, applying the DLBCL90 assay on the NanoString platform (NanoString Technologies, Seattle, WA) and FISH break-apart probes for MYC, BCL2 and BCL6 were used for identification of HGBL-DH/TH. Results: The COO assay assigned 54%, 31% and 15% of the tumors to the GCB, activated B-cell like (ABC) and unclassified group, respectively. The ABC- and unclassified DLBCLs showed a trend towards inferior outcome when compared to the GCB-group (OS: 59%, 66%, 91%, p=0.076, PFS: 74%, 59%, 85%, p=0.122, FFS: 63%, 51%, 83%, p=0.052, respectively). The DHITsig was only seen in the GCB subtype. Of the patients with the GCB subtype, 5 (10%) and 11 patients (23%) were assigned to the DHITsig-positive and DHITsig-indeterminate group, respectively. FISH results were available for 71 samples, and 6 were identified as HGBL-DH/TH-BCL2. Four of them were assigned to the DHITsig-positive group, while 1 case was assigned to the DHITsig-indeterminate group with a 79% probability of belonging to the DHITsig-positive group (cut-off 80%). The last case was a triple-hit tumor that was assigned to the DHITsig-negative group. This patient had a favorable outcome with a complete remission after first line therapy, and was still in remission at the last follow-up 45 months after diagnosis. Overall, after a median follow-up of 64 months, 17 patients (19%) experienced relapse and 13 patients (15%) had died. Within the GCB subgroup, there were no significant differences in clinical outcome (OS, PFS, FFS) between the DHITsig positive, negative and indeterminate groups when analyzed as separate groups, or when the positive/indeterminate groups were merged (figure). Conclusion: We confirm that the DLBCL90 gene expression assay identifies HGBL-DH/TH-BCL2 in FFPE biopsies. This, together with a rapid turnaround time, makes it an attractive alternative to FISH for double-hit assignment in the clinical setting. In our cohort of young-high risk patients treated with dose-dense immunochemotherapy, the DHITsig was not associated with inferior survival. Of note, neither was the HGBL-DH/TH defined by FISH. This may be due to the intensified treatment, overcoming the poor prognostic impact of the double-hit biology. Disclosures Jørgensen: Gilead: Membership on an entity's Board of Directors or advisory committees; Roche: Membership on an entity's Board of Directors or advisory committees. Jerkeman:Roche: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; Gilead: Honoraria, Research Funding; Acerta: Honoraria, Research Funding; Celgene: Honoraria, Research Funding. Scott:Roche/Genentech: Research Funding; Celgene: Consultancy; Janssen: Consultancy, Research Funding; NanoString: Patents & Royalties: Named inventor on a patent licensed to NanoSting [Institution], Research Funding. Holte:Novartis: Honoraria, Other: Advisory board.

Background In neuroblastoma (NB), the most powerful prognostic marker, the MYCN amplification (MNA), occasionally shows intratumoural heterogeneity (ITH), i.e. coexistence of MYCN-amplified and non-MYCN-amplified tumour cell clones, called heterogeneous MNA (hetMNA). Prognostication and therapy allocation are still unsolved issues. Methods The SIOPEN Biology group analysed 99 hetMNA NBs focussing on the prognostic significance of MYCN ITH. Results Patients 18 m: 0.67 ± 0.14, p = 0.011; metastatic: 18 m: 0.28 ± 0.09, p = 0.084). The genomic 'background’, but not MNA clone sizes, correlated significantly with relapse frequency and OS. No relapses occurred in cases of only numerical chromosomal aberrations. Infiltrated bone marrows and relapse tumour cells mostly displayed no MNA. However, one stage 4s tumour with segmental chromosomal aberrations showed a homogeneous MNA in the relapse. Conclusions This study provides a rationale for the necessary distinction between heterogeneous and homogeneous MNA. HetMNA tumours have to be evaluated individually, taking age, stage and, most importantly, genomic background into account to avoid unnecessary upgrading of risk/overtreatment, especially in infants, as well as in order to identify tumours prone to developing homogeneous MNA.

Purpose To report a bilateral uveal melanoma detected in a micrometastasis study. Method Case report. Results At enucleation of a circumpapillary amelanotic mixed melanoma in a patient with ocular melanocytosis, a pigmented lesion in the other eye was detected, thought to be a naevus. BAP1 was positive showing nuclear staining of the tumour cells. Seven years later the naevus showed growth and development of a retinal detachment. FNAB disclosed monosomy 3 in the spindle tumour cells. Conclusion A case of bilateral melanoma with long-term survival without metastatic diseases is reported. Different gene expressions in the two eyes were revealed. The case is a reminder that follow-up over years is essential in patients with a uveal melanoma, especially with ocular melanocytosis.

Background: The prognostic impact of segmental chromosome alterations (SCAs) in children older than 1 year, diagnosed with localised unresectable neuroblastoma (NB) without MYCN amplification enrolled in the European Unresectable Neuroblastoma (EUNB) protocol is still to be clarified, while, for other group of patients, the presence of SCAs is associated with poor prognosis. Methods: To understand the role of SCAs we performed multilocus/pangenomic analysis of 98 tumour samples from patients enrolled in the EUNB protocol. Results: Age at diagnosis was categorised into two groups using 18 months as the age cutoff. Significant difference in the presence of SCAs was seen in tumours of patients between 12 and 18 months and over 18 months of age at diagnosis, respectively (P = 0.04). A significant correlation (P = 0.03) was observed between number of SCAs per tumour and age. Event-free (EFS) and overall survival (OS) were calculated in both age groups, according to both the presence and number of SCAs. In older patients, a poorer survival was associated with the presence of SCAs (EFS = 46% vs 75%, P = 0.023; OS = 66.8% vs 100%, P = 0.003). Moreover, OS of older patients inversely correlated with number of SCAs (P = 0.002). Finally, SCAs provided additional prognostic information beyond histoprognosis, as their presence was associated with poorer OS in patients over 18 months with unfavourable International Neuroblastoma Pathology Classification (INPC) histopathology (P = 0.018). Conclusions: The presence of SCAs is a negative prognostic marker that impairs outcome of patients over the age of 18 months with localised unresectable NB without MYCN amplification, especially when more than one SCA is present. Moreover, in older patients with unfavourable INPC tumour histoprognosis, the presence of SCAs significantly affects OS.

T cells modified to express chimeric antigen receptor (CAR) targeting CD19 have produced remarkable clinical responses in patients with relapsed/refractory B-cell acute lymphoblastic leukemia (B-ALL). CD19CAR T-cell therapy has also demonstrated prominent effects in B-cell non-Hodgkin lymphoma (B-NHL) patients. However, a subset of patients who relapse after CD19CAR T-cell therapy have outgrowth of CD19-negative tumor cells. Hence, development of alternative CARs targeting other B-cell markers represents an unmet medical need for B-ALL and B-NHL. Here, we confirmed previous data by showing that B-NHL overall have high expression of CD37. A second generation CD37CAR was designed and its efficacy in T cells was compared to that of CD19CAR. In vitro assessment of cytotoxicity and T-cell function upon co-culture of the CAR T cells with different target B-cell lymphoma cell lines demonstrated comparable efficacy between the two CARs. In an aggressive B-cell lymphoma xenograft model, CD37CAR T cells were as potent as CD19CAR T cells in controlling tumor growth. In a second xenograft model, using U2932 lymphoma cells containing a CD19-negative subpopulation, CD37CAR T cells efficiently controlled tumors and cured the mice while CD19CAR T cells had limited effect. We further show that, unlike CD19CAR, CD37CAR was not sensitive to antigen masking. Finally, CD37CAR reactivity was restricted to B-lineage cells. Collectively, our results demonstrated that CD37CAR T cells effectively can eradicate B-cell lymphoma tumors also when CD19 antigen expression is lost, and support further clinical testing for patients with relapsed/refractory B-NHL. Citation Format: Pierre Dillard, Hakan Köksal, Sarah Josefsson, Solrun Melkorka Maggadottir, Sylvie Pollmann, Anne Fåne, Yngvild Nuvin Blaker, Klaus Beiske, Kanutte Huse, Ane Kolstad, Harald Holte, Gunnar Kvalheim, Erlend Bremertun Smeland, June Myklebust, Else Marit Inderberg, Sebastien Wälchli. Preclinical development of CD37CAR T-cell therapy for treatment of B-cell lymphoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1422.

Background. Survival of patients with high-risk diffuse large B-cell lymphoma (DLBCL) is suboptimal, and the risk of central nervous system (CNS) progression is relatively high. We investigated the efficacy of dose-dense chemoimmunotherapy and systemic CNS prophylaxis in two Nordic trials including patients less than 65 years with high-risk DLBCL. We combined individual patient data from these trials to compare clinical outcome and biological prognostic factors in patients treated with CNS prophylaxis given in the beginning (CHIC) versus at the end (CRY-04) of therapy. Patients and methods. In CRY-04 study, patients were treated with six courses of R-CHOEP14 followed by HD-Mtx and HD-Ara-C. In CHIC trial, treatment started with two courses of HD-Mtx in combination with R-CHOP14, followed by four courses of R-CHOEP-14 and one course of R-HD-AraC. In addition, liposomal AraC was administered intrathecally at courses 1, 3 and 5. For the correlative studies, formalin fixed paraffin embedded pretreatment tumor samples were analyzed by fluorescent in situ hybridization for BCL2 and c-MYC breakpoints and by immunochemistry for CD10, BCL6, MUM1, MYC and BCL2 expression. Germinal center B-cell-like (GCB)/non-GCB) subclassification was performed according to Hans algorithm. Results. Among 303 patients enrolled in the trials (CRY-04, n=160 and CHIC, n=143), 295 (CRY-04, n=154 and CHIC, n=139) were evaluable for baseline characteristics and outcome. Median age (54 and 56 years, p=0.222), male/female ratio, stage, and aaIPI scores were comparable in the two cohorts. CHIC regimen improved outcome over CRY-04; the findings included 4-year estimates of PFS (81% vs 66%, p=0.003), OS (83% and 79%, p=ns) and cumulative incidence rates of CNS progression (2.4% and 5.0%, p=ns). Treatment with the CHIC regimen reduced the risk of systemic progression (aaIPI adjusted RR=0.489, 95%CI 0.308-0.777, p=0.002). PFS benefit with CHIC over CRY-04 was observed across pre-specified subgroups, and particularly in patients less than 60 years old (p=0.008). In the entire study population, dual protein expression (DPE) of BCL2 and MYC was the only parameter to be significantly correlated with a worse PFS (4-y PFS 77% vs 50%, p=0.024; RR=2.300, 95% CI 1.088-4.860, p=0.029). Neither any single immunohistochemical marker nor the GCB/non-GCB subtype or MYC/BCL2-translocations significantly affected outcome. However, when treatment interaction was tested, MYC/BCL2 double hit status (DHL; 13%) predicted poor outcome among patients treated with CRY-04 regimen compared with patients who received CHIC regimen (4-y PFS; 38% vs 78%, p=0.086). GCB subtype and BCL2 positivity were also associated with better outcome in the CHIC cohort (4 y PFS; 63% vs 84%, p=0.011 and 61% vs 80%, p=0.007, respectively), whereas there were no significant survival differences between these regimens among the patients with non-GCB subtype, BCL2 negative DLBCL or DPE lymphomas. Conclusions. Our results derived from trial data with homogenous treatment support the use of HD-Mtx in the beginning rather than at the end of therapy. The survival benefit related to CHIC regimen over CRY-04 is due to better systemic control of the disease, and at least partly linked to improved survival among patients with GCB subtype, BCL2 positivity and DHL. Disclosures Leppa: Takeda: Consultancy, Research Funding; Janssen: Consultancy, Research Funding; Bayer: Research Funding; Roche: Consultancy, Honoraria, Research Funding; Celgene: Consultancy. Holte:Novartis Pharmaceuticals Corporation: Membership on an entity's Board of Directors or advisory committees; Roche, Norway: Research Funding.

A 15-month-old boy was diagnosed with malignant hypertension caused by a catecholamine excreting retroperitoneal paraganglioma consisting of a composite phaeochromocytoma/differentiating neuroblastoma. After alpha-blockade the tumor was excised. No adjuvant treatment was given, and he is doing well eight years after the diagnosis. The patient is the first child known to have an extra-adrenal retroperitoneal composite tumor, and also the youngest child with a composite phaeochromocytoma/neuroblastoma reported in the English literature.

The tumour microenvironment influences outcome in patients with follicular lymphoma (FL), but its impact on transformation is less studied. We investigated the prognostic significance of the tumour microenvironment on transformation and survival in FL patients treated in the rituximab era. We examined diagnostic and transformed biopsies from 52 FL patients using antibodies against CD3, CD4, CD8, CD21 (CR2), CD57 (B3GAT1), CD68, FOXP3, TIA1, PD-1 (PDCD1), PD-L1 (CD274) and PAX5. Results were compared with a second cohort of 40 FL patients without signs of transformation during a minimum of five years observation time. Cell numbers and localization were semi-quantitatively assessed. Better developed CD21+ follicular dendritic cell (FDC) meshworks at diagnosis was a negative prognostic factor for overall survival (OS), progression-free survival (PFS) and time to transformation (TTT) in patients with subsequently transformed FL. Remnants of FDC meshworks at transformation were associated with shorter OS and PFS from transformation. High degrees of intrafollicular CD68+ and PD-L1+ macrophage infiltration, high total area scores and an extrafollicular/diffuse pattern of FOXP3+ T cells and high intrafollicular scores of CD4+ T cells at diagnosis were associated with shorter TTT. Scores of several T-cell subset markers from the combined patient cohorts were predictive for transformation, especially CD4 and CD57.

Background Of 4,706 peripheral neuroblastic tumors (pNTs) registered on the Children’s Cancer Group and Children’s Oncology Group Neuroblastoma Study between 1989 and 2010, 51 cases (1.1%) had genotype-phenotype discordance characterized by MYCN amplification (indicating poor prognosis) and Favorable Histology (indicating better prognosis).

BACKGROUND The clinical courses of chronic lymphocytic leukaemia (CLL) are very heterogeneous. Biological markers that provide good prognostic information at the time of diagnosis are available. The aim of the study was to determine the prevalence of these markers in a population-based material. MATERIAL AND METHOD Biological markers were examined using standard laboratory methods after obtaining an informed consent statement from patients diagnosed with chronic lymphocytic leukaemia in the period 1.10.2007-31.12.2009. RESULTS There were 388 new cases of chronic lymphocytic leukaemia during the study period, and 236 patients (61%) were included in the study. Of 222 patients, 178 (80%) were in Binet's stage A, 26 (12%) in stage B and 18 (8%) in stage C. The V(H) gene was mutated in 69% and unmutated in 31% of cases. Cytogenetic aberrations were found in 68%: del(13q14) in 48%, trisomy 12 in 13%, del(11q22) in 10% and del(17p13) in 7%. CD38-positive disease was found in 28% of the patients. The V(H) gene was mutated in 67% of the patients in Binet's stage A, and in the majority of these a mutated V(H) gene was associated with non-expression of CD38 and del(13q14). INTERPRETATION At the time of diagnosis, most patients are asymptomatic and do not need treatment. The biological markers that indicate a favourable prognosis occur most frequently in this group. Markers that indicate a poor prognosis occur more frequently in the group that has symptoms at the time of diagnosis.

BACKGROUND: In neuroblastoma (NB), the presence of segmental chromosome alterations (SCAs) is associated with a higher risk of relapse. METHODS: In order to analyse the role of SCAs in infants with localised unresectable/disseminated NB without MYCN amplification, we have performed an array CGH analysis of tumours from infants enrolled in the prospective European INES trials. RESULTS: Tumour samples from 218 out of 300 enroled patients could be analysed. Segmental chromosome alterations were observed in 11%, 20% and 59% of infants enroled in trials INES99.1 (localised unresectable NB), INES99.2 (stage 4s) and INES99.3 (stage 4) (P

We present seven cases of mantle cell lymphoma with morphological features of marginal-zone lymphoma. Of particular interest, four of the patients had predominant involvement of the gastrointestinal tract. All cases displayed the translocation t(11;14)(q13;q32) and expressed cyclin D1. Cytogenetic analysis revealed trisomy 3 in one case and somatic hypermutation of immunoglobulin heavy genes could be demonstrated in two out of four cases. The latter features are reminiscent of marginal-zone lymphoma. The localization of these lymphomas mainly in the gastrointestinal tract and the higher exposure to antigens in this area may explain why this variant of mantle cell lymphoma harbours features of marginal-zone lymphoma.

Objectives Targeted therapies in non-small cell lung cancer (NSCLC) now also include inhibitors against mutated BRAF. We present clinicopathological characteristics of nearly one thousand unselected NSCLC patients tested for the targetable V600E/K BRAF-mutation. Material and methods NSCLC routinely tested for EGFR-mutations at Oslo University Hospital in the period February 2011–July 2013 were tested for V600E/K BRAF-mutations using a PCR-based method. Results We found a BRAF-mutation frequency of 1.7% in the total cohort of 979 patients, and 2.3% among 646 adenocarcinomas. One of the BRAF-positive samples was also KRAS-mutated, and one had an ALK-translocation. None of 231 squamous cell carcinomas were BRAF-mutated. The proportion of never-smokers among BRAF-positives was high (29%). Conclusion BRAF-mutation analysis should be part of the subtyping of non-squamous NSCLC.

Background: The first phase of the MetAction trial established the required diagnostic infrastructure, implemented security-approved systems for handling of sensitive information, educated the Trial Team within the context of tumor boards, and estimated costs of the initiative within public health services. The endeavor enabled expedited and safe mutation profiling of metastatic tumors in order to offer molecularly matched medication for end-stage cancer (Ree et al., ESMO Open 2017;2:e000158). The aim of the second trial phase was to investigate the utility of the MetAction pipeline in clinical practice. Procedures: An eligible patient with end-stage metastatic disease from any origin had been on the previous line of systemic therapy for 6 or more weeks with radiologic evaluation intervals of 6-12 weeks and disease progression according to the Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1. Biopsy-sampled metastatic tissue was analyzed by DNA sequencing (Ion Oncomine™ Comprehensive Panel), where called variants were filtered prior to assessment and prioritization, supplemented with fluorescence in situ hybridization to cover relevant biomarkers. The Molecular Tumor Board interpreted the findings within the likelihood of signaling pathway activity, for the sequential Clinical Tumor Board to conclude on potential systemic tumor-directed medication. On study therapy, radiologic work-up was performed every 8 weeks. The primary objective was to compare progression-free survival (PFS) on study treatment, termed Period-B, with PFS for the most recent therapy, termed Period-A. If Period-B/Period-A was ≥1.3, the study therapy was deemed to be of benefit. The incidence of diagnostic adverse events and treatment-related grade 3-5 Common Terminology Criteria for Adverse Events (CTCAE) toxicities was secondary end points. Results: 26 patients were enrolled. Biopsy procedures were undertaken at lung or pleural sites (6 cases), liver or peritoneal sites (19 cases), and an inguinal lymph node (1 case), and did not cause adverse events. Histologic entities were 18 adenocarcinomas (AC), 2 undifferentiated carcinomas, 1 case each of cholangiocarcinoma and squamous cell carcinoma, and 4 different sarcoma entities. 13 patients were found eligible for off-label use of molecularly matched therapy (inhibitor of ALK-, BRAF-, EGFR-, FGFR-, mTOR-, PARP-, ROS1-, or PD-1-mediated signaling). Among the 10 individuals who received study treatment until radiologic evaluation, 5 met the primary end point. The patient with cholangiocarcinoma and a patient with rectal AC primaries, both given crizotinib, obtained Period-B/Period-A outcome slightly better than 1.3. Notably, 3 patients with colon AC primaries, receiving either a combination of panitumumab with vemurafenib or chemotherapy or single-agent pembrolizumab, obtained long-lasting responses. In addition, 1 colon AC patient receiving pembrolizumab with RECIST progression (i.e., primary end point failure) before a long-lasting response to off-protocol continuation, reported CTCAE grade 3 toxicity (a colitis event that immediately resolved on high-dose prednisolone). Conclusion: MetAction procedures and treatments were safe. 15% (4/26) of patients with progressing end-stage cancer had the disease course substantially reversed by this biomarker-directed therapy approach. Citation Format: Anne Hansen Ree, Kjersti Flatmark, Vigdis Nygaard, Daniel Heinrich, Kjetil Boye, Svein Dueland, Vegard Nygaard, Eivind Hovig, Klaus Beiske, Marius Lund-Iversen, Vivi A. Flørenes, Christin Johansen, Inger Riise Bergheim, Menaka Sathermugathevan, Sigve Nakken, Gry A. Geitvik, Ole C. Lingjærde, Anne-Lise Børresen-Dale, Hege G. Russnes, Gunhild M. Mælandsmo. The MetAction trial: long-lasting responses to molecularly matched therapy in end-stage cancer [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2017 Oct 26-30; Philadelphia, PA. Philadelphia (PA): AACR; Mol Cancer Ther 2018;17(1 Suppl):Abstract nr A101.

Summary Common variable immunodeficiency (CVID) is a heterogeneous syndrome characterized by defective immunoglobulin production and high frequency of bacterial infections, autoimmunity and manifestations of chronic inflammation. The homeostatic chemokines CCL19 and CCL21 and their receptor CCR7 are associated with modulation of inflammatory responses. CVID patients have decreased proportions of CCR7+ T cells in peripheral blood and we hypothesized a further dysregulation of CCL19/CCL21/CCR7 in CVID. Serum levels of CCL19 and CCL21 were compared in CVID patients and controls. T cell expression of CCR7 was related to clinical characteristics in CVID patients. Spleens extirpated from CVID patients were analysed for expression of CCL19, CCL21 and CCR7. Peripheral blood mononuclear cells (PBMC) from CVID patients and controls were analysed for cytokine response on stimulation with CCL19 and CCL21. The main findings were: (i) CVID patients have raised serum levels of CCL19 and CCL21 independently of features of chronic inflammation; (ii) CCL19 and CCR7 have similar expression in spleens from CVID patients and controls, while CCL21 is variably down-regulated in spleens from patients; (iii) T cell expression of CCR7 is particularly low in patients characterized by chronic inflammation in vivo; and (iv) PBMC from CVID patients had attenuated cytokine response to stimulation with CCL19 and CCL21. CVID patients have raised circulatory levels of CCL19 and CCL21, and an attenuated cytokine response to stimulation with these chemokines. Because CCR7, CCL19 and CCL21 are key mediators balancing immunity and tolerance in the immune system, the abnormalities of these mediators might contribute to the profound immune dysregulation seen in CVID.

Summary Background More accurate prognostic assessment of patients with neuroblastoma is required to better inform the choice of risk-related therapy. The aim of this study is to develop and validate a gene-expression signature to improve outcome prediction. Methods 59 genes were selected using an innovative data-mining strategy, and were profiled in the largest neuroblastoma patient series (n=579) to date using real-time quantitative PCR starting from only 20 ng of RNA. A multigene-expression signature was built using 30 training samples, tested on 313 test samples, and subsequently validated in a blind study on an independent set of 236 tumours. Findings The signature has a performance, sensitivity, and specificity of 85·4% (95% CI 77·7–93·2), 84·4% (66·5–94·1), and 86·5% (81·1–90·6), respectively, to predict patient outcome. Multivariate analysis indicates that the signature is a significant independent predictor of overall survival and progression-free survival after controlling for currently used risk factors: patients with high molecular risk have a higher risk of death from disease and higher risk of relapse or progression than patients with low molecular risk (odds ratio 19·32 [95% CI 6·50–57·43] and 3·96 [1·97–7·97] for overall survival and progression-free survival, respectively, both p MYCN status, age, International Neuroblastoma Staging System stage, ploidy, International Neuroblastoma Pathology Classification grade of differentiation, and mitosis karyorrhexis index (odds ratios between 4·81 and 10·53 depending on the model for overall survival and 3·68 [95% CI 2·01–6·71] for progression-free survival). Interpretation The 59-gene expression signature is an accurate predictor of outcome in patients with neuroblastoma. The signature is an independent risk predictor, identifying patients with an increased risk of poor outcome in the current clinical-risk groups. The method and signature is suitable for routine laboratory testing, and should be evaluated in prospective studies. Funding The Belgian Foundation Against Cancer, the Children Cancer Fund Ghent, the Belgian Society of Paediatric Haematology and Oncology, the Belgian Kid's Fund and the Fondation Nuovo-Soldati (JV), the Fund for Scientific Research Flanders (KDP, JH), the Fund for Scientific Research Flanders, the Institute for the Promotion of Innovation by Science and Technology in Flanders, Strategisch basisonderzoek, the Fondation Fournier Majoie pour l'Innovation, the Instituto Carlos III, the Italian Neuroblastoma Foundation, the European Community under the FP6, and the Belgian programme of Interuniversity Poles of Attraction.

The analysis of a small number of patients with atypical chronic myeloid leukemia showing balanced chromosomal translocations has revealed diverse tyrosine kinase fusion genes, most commonly involving FGFR1, PDGFRA, PDGFRB, JAK2, and ABL. We present a case of aCML with a 3q22;21q22-translocation that led to truncation of the receptor-like tyrosine kinase (RYK) gene and its juxtaposition with sequences from chromosome 21 including the ATP5O gene coding for a mitochondrial ATP synthase. The resulting fusion was not in frame, however, which is why we speculate that an abrogated RYK gene product rather than a chimeric protein might be the leukemogenic result.

Transdifferentiation of B cell lymphoma of germinal center cell origin to histiocytic sarcoma has recently been described but is a rare occurrence. The cause for loss of B cell differentiation in these lymphomas is unknown. We investigated whether somatic hypermutation of the PAX-5 gene, a transcription factor that is important for maintaining B cell identity and is frequently mutated in B cell lymphomas of germinal center cell origin, might be a cause for loss of PAX-5 expression and thus B cell phenotype. However, no somatic hypermutation of the PAX-5 gene was detected in the two cases we studied. The molecular basis for transdifferentiation of B cell lymphoma to histiocytic sarcoma remains therefore unresolved.

BACKGROUND: Large granular lymphocytic leukaemia (LGL-leukaemia) is considered a rare disease. LGL-leukaemia is usually of the T-cell type, but a minority displays an NK-cell phenotype. Incidence and prevalence are unknown. MATERIAL AND METHODS: We identified patients with LGL-leukaemia (with well-defined diagnostic criteria) diagnosed at Rikshospitalet University Hospital between 01.10.2001 and 31.12.2007. Their medical records were assessed retrospectively. RESULTS: LGL-leukaemia was diagnosed in 52 patients, 26 women and 26 men, median age of 59 (26 - 86) years, during the study period. The leukaemia displayed NK-cell phenotype in one patient and T-cell phenotype in the remaining 51 patients. Slightly more than one third of the patients were asymptomatic. Cytopenia, mostly neutropenia, was usually the cause of the clinical phenotype in symptomatic patients. Co-morbidity with autoimmune disease was common, and we also found a high prevalence of clonal B-cell disease (17 %). INTERPRETATION: Our data support the notion that LGL-leukaemia is under-diagnosed. Unexplained cytopenias should suggest the possibility of LGL-leukaemia, and appropriate diagnostic measures should be undertaken. An early diagnosis may save patients an extensive and unnecessary diagnostic work-up and ensure that a simple and effective treatment is offered.

Aims: To investigate the relationship between phenotype and genotype in oligodendroglial tumours and evaluate whether 1p/19q status can be reliably predicted from histological findings. Methods and results: Three neuropathologists reviewed the association between 10 histological variables, location and genetic losses at 1p, 19q and 17p13 in 63 oligodendroglial tumours (cohort 1). Based on these findings, a multiple logistic regression model for prediction of 1p/19q status was constructed. The ability of this model to predict 1p/19q status was tested on cohort 2, comprising 20 oligodendroglial tumours. Loss of heterozygosity at 1p, 19q and 17p13 was analysed using polymerase chain reaction. Combined 1p/19q loss and losses at 17p13 were mutually exclusive (P