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Among the different biomarkers predicting response in chronic lymphocytic leukemia (CLL), the most influential parameters are the mutational status of the IGHV genes and the presence of TP53 gene disruptions. Nevertheless, these important assessments are not readily available in most centers dealing with CLL patients. To provide this molecular testing across the country, the Spanish Cooperative Group on CLL (GELLC) established a network of four analytical reference centers. A total of 2153 samples from 256 centers were analyzed over a period of 30 months. In 9% of the patients, we found pathological mutations in the TP53 gene, whereas 48.96% were classified as IGHV unmutated. Results of the satisfaction survey of the program showed a Net Promoter Score of 85.15. Building a national network for molecular testing in CLL allowed the CLL population a broad access to complex biomarkers analysis that should translate into a more accurate and informed therapeutic decision-making.

Burkitt's monomorphic posttransplant lymphoproliferative disorder (B-PTLD) is an uncommon subtype of PTLD. Owing to the paucity of this complication, clinical characteristics and outcome has not been fully described. Clinical characteristics and outcomes of 20 patients diagnosed with B-PTLD from 10 transplant centers belonging to the GEL/TAMO group were reviewed. Median time from transplant to B-PTLD was 7.2 years. All the cases fulfill the morphologic and genetic criteria of B-PTLD, whereas Epstein-Barr virus (EBV) was detected in 70% of cases. Patients were treated with different chemotherapy combinations, and three patients received upfront rituximab monotherapy. The great majority of patients receiving CHOP-like regimens attained a complete response (CR) (73%), similar to that obtained with dose-intensive chemotherapy (83% CR). In contrast, patients receiving upfront rituximab monotherapy required subsequent chemotherapy. Two patients (10%) died during treatment due to infection. The median progression-free survival and overall survival (OS) were 16 months and 139 months, respectively. When analyzing variables predicting for OS, we found that patients with bone marrow involvement had an adverse prognosis, with a median OS of 6 months (p = 0.008). In conclusion, B-PTLD is an uncommon complication usually associated with EBV infection and with an aggressive clinical course, particularly in patients with bone marrow involvement. High-dose chemoimmunotherapy obtained similar responses to R-CHOP, suggesting that R-CHOP could be an adequate alternative for these patients. In contrast, rituximab monotherapy does not seem to be effective enough to control the disease.

Immunoglobulin M (IgM) monoclonal gammopathies show considerable variability, involving three different stages of presentation: IgM monoclonal gammopathy of undetermined significance (IgM-MGUS), asymptomatic Waldenström's macroglobulinemia (AWM), and symptomatic WM (SWM). Despite recent findings about the genomic and transcriptomic characteristics of such disorders, we know little about the causes of this clinical heterogeneity or the mechanisms involved in the progression from indolent to symptomatic forms. To clarify these matters, we have performed a gene expression and mutational study in a well-characterized cohort of 69 patients, distinguishing between the three disease presentations in an attempt to establish the relationship with the clinical and biological features of the patients. Results showed that the frequency of genetic alterations progressively increased from IgM-MGUS to AWM and SWM. This means that, in contrast to MYD88 p.L265P and CXCR4 WHIM mutations, present from the beginning of the pathogenesis, most of them would be acquired during the course of the disease. Moreover, the expression study revealed a higher level of expression of genes belonging to the Toll-like receptor (TLR) signaling pathway in symptomatic versus indolent forms, which was also reflected in the disease presentation and prognosis. In conclusion, our findings showed that IgM monoclonal gammopathies present higher mutational burden as the disease progresses, in parallel to the upregulation of relevant pathogenic pathways. This study provides a translational view of the genomic basis of WM pathogenesis.

Chromosome 1q gains and 13q deletions are common cytogenetic aberrations in multiple myeloma (MM) that confer a poor prognosis. There are several techniques for the targeted study of these alterations, but interphase fluorescence in situ hybridization (FISH) is the current gold standard. The aim of the present study was to validate quantitative PCR (qPCR) as an alternative to FISH studies in CD138+-enriched plasma cells (PCs) from MM patients at diagnosis. We analyzed 1q gains and 13q deletions by qPCR in 57 and 60 MM patients, respectively. qPCR applicability was 84 and 88% for 1q and 13q, respectively. The qPCR and FISH methods had a sensitivity and specificity of 88 and 71% for 1q gains, and 79 and 100% for 13q deletions. A second qPCR assay for each region was carried out to confirm the previous results. Paired qPCR (two assays) and FISH results were available from 53 MM patients: 26 for 1q amplification and 27 for 13q deletion. qPCR assays gave concordant results (qPCR-consistent) in 20 of the 26 (77%) 1q gains and 25 of the 27 (93%) 13q deletions. Considering only the consistent data, the overall concordance among qPCR and FISH was 85 and 100% for 1q gains and 13q deletions, respectively. Our results show a substantial agreement between qPCR and the gold standard FISH technique, indicating the potential of qPCR as an alternative approach, particularly when the starting material is too scarce or cells are too damaged to obtain accurate results from FISH studies.

Copy number analysis can be useful for assessing prognosis in diffuse large B cell lymphoma (DLBCL). We analyzed copy number data from tumor samples of 60 patients diagnosed with DLBCL de novo and their matched normal samples. We detected 63 recurrent copy number alterations (CNAs), including 33 gains, 30 losses, and nine recurrent acquired copy number neutral loss of heterozygosity (CNN-LOH). Interestingly, 20 % of cases acquired CNN-LOH of 6p21 locus, which involves the HLA region. In normal cells, there were no CNAs but we observed CNN-LOH involving some key lymphoma regions such as 6p21 and 9p24.1 (5 %) and 17p13.1 (2.5 %) in DLBCL patients. Furthermore, a model with some specific CNA was able to predict the subtype of DLBCL, 1p36.32 and 10q23.31 losses being restricted to germinal center B cell-like (GCB) DLBCL. In contrast, 8p23.3 losses and 11q24.3 gains were strongly associated with the non-GCB subtype. A poor prognosis was associated with biallelic inactivation of TP53 or 18p11.32 losses, while prognosis was better in cases carrying 11q24.3 gains. In summary, CNA abnormalities identify specific DLBCL groups, and we describe CNN-LOH in germline cells from DLBCL patients that are associated with genes that probably play a key role in DLBCL development.

This study analyzes patients with head and neck diffuse large B cell lymphoma (HN-DLBCL), focusing on the differences in the biological characteristics and prognosis of lymphomas of nodal and extranodal origin. We have included 72 patients with stage I-II HN-DLBCL who had updated survival information and diagnostic paraffin-embedded tissue blocks available for review. Non-germinal center phenotype (73.7 vs. 32.4 %, P = 0.001) and high level of Bcl-2 expression (78.9 vs. 52.9 %, P = 0.025) were more frequent in nodal than extranodal lymphomas. Univariate analyses indicated that bulky disease, Ann Arbor stage II, high level of Ki-67 expression, and primary nodal disease had adverse effects on complete remission (CR), but these effects were confirmed in a multivariate analysis for primary nodal disease and bulky disease. Patients with primary extranodal lymphoma also had better overall survival (OS) (87.7 vs. 72.5 %, P = 0.04) and event-free survival (EFS) (84 vs. 58.5 %, P = 0.046) than patients with nodal disease, although in the multivariate analysis, only Ann Arbor stage II continued to predict worse OS and EFS, whereas bulky disease was an independent prognostic factor only for EFS. We found significant differences in the biological characteristics and prognosis between primary nodal and extranodal HN-DLBCL.

We have evaluated the use of CD138+ positively selected bone marrow samples to identify a molecular target for minimal residual disease assessment by polymerase chain reaction (PCR) in 25 untreated patients with multiple myeloma. A fraction of each sample was used for CD138+ selection, and the rest served as a reference control. VDJH, DJH, and Kde gene rearrangements were tested for amplification according to the BIOMED-2 Concerted Action. PCR products were directly sequenced in an automated ABI 3130 DNA sequencer using Big-Dye terminators. Within the CD138+ selected group, VDJH rearrangements were detected in all cases (100 %), DJH in 16 (64 %), and Kde in 18 (72 %) cases; whereas in the control samples, VDJH, DJH, and Kde rearrangements were detected in 19 (76 %), 11 (44 %), and 12 (48 %) cases, respectively. After sequencing, 24 (96 %) cases within the CD138+ group had a PCR target for MRD detection compared with 15 (60 %) cases in the control group. We conclude that the use of CD138+ positively selected bone marrow samples increases the applicability of minimal residual disease studies by PCR in patients with multiple myeloma.

We have analyzed brain and acute leukemia, cytoplasmic (BAALC) gene expression and other genetic markers (ERG, EVI1, MN1, PRAME, WT1, FLT3, and NPM1 mutations) in 127 intermediate-risk acute myeloid leukemia (AML) patients: 98 cytogenetically normal and 29 with intermediate-risk cytogenetic alterations. High versus low BAALC expressers showed a higher refractoriness to induction treatment (31% vs 10%; p = .005), lower complete remission rate after salvage therapy (82% vs 97%; p = .010), and lower 3-year overall (23% vs 58%, p < .001) and relapse-free survival (26% vs 52%, p = .006). Similar results were found when cytogenetic subgroups were analyzed separately. Multivariate models confirmed the unfavorable prognosis of this marker. In conclusion, BAALC is a relevant prognostic marker in intermediate-risk AML.