High-grade B-cell lymphomas with MYC and BCL2 translocations lack tumor-associated macrophages and PD-L1 expression: A possible noninflamed subgroup.

We investigated the intratumoral source of PD-L1 expression and the infiltration of tumor-associated macrophages (TAMs) in large B-cell lymphomas (LBCLs) with or without MYC-translocation, as well as possible correlations to BCL2-and BCL6-translocations and cell of origin (COO). One-hundred and twenty-six patient samples were studied in a cohort enriched for MYC-translocated tumors with 34 samples carrying this translocation. Demonstration of intratumoral distribution and cellular source of PD-L1 was enabled by immunohistochemical (IHC) dual staining specifically highlighting PD-L1 expression in lymphoma B-cells with antibodies against PD-L1 and PAX5. Additional IHC with antibodies against CD68 and CD163 identified TAMs. We found that CD68-positive TAMs were the main source of PD-L1 protein expression in contrast to lymphoma B cells which rarely expressed PD-L1. Semiquantitative IHC demonstrated a significant correlation between CD68 and PD-L1 protein expression. Unsupervised hierarchical analysis of PD-L1, CD68, and CD163 IHC data subsequently demonstrated three potential clusters defined by expression of the three biomarkers. Cluster A consisted of patient samples with significantly lower expression of PD-L1, CD68, and CD163, but also significantly higher prevalence of BCL2-translocation and MYC-BCL2-double-hit (DH) compared to the other two clusters. In cluster C we found a significant accumulation of BCL6 translocated tumors. This cluster in contrast had the highest protein expression of PD-L1, CD68, and CD163. Cluster B tumors had an intermediate expression of the three biomarkers, but no accumulation of the specific genetic translocations. Our data, which were based on morphological analysis, immunophenotyping and genotyping by fluorescence in situ hybridization were in line with new concepts of LBCL taxonomy integrating genetic, phenotypical, and immunological characteristics with identification of new subgroups where MYC translocation and MYC-BCL2 DH may identify a noninflamed subtype. These findings may furthermore hold significant predictive value especially regarding immune checkpoint blockade therapy, but further molecular characterization should be done to substantiate this hypothesis.

Genetic and Functional Drivers of Diffuse Large B Cell Lymphoma.

Diffuse large B cell lymphoma (DLBCL) is the most common form of blood cancer and is characterized by a striking degree of genetic and clinical heterogeneity. This heterogeneity poses a major barrier to understanding the genetic basis of the disease and its response to therapy. Here, we performed an integrative analysis of whole-exome sequencing and transcriptome sequencing in a cohort of 1,001 DLBCL patients to comprehensively define the landscape of 150 genetic drivers of the disease. We characterized the functional impact of these genes using an unbiased CRISPR screen of DLBCL cell lines to define oncogenes that promote cell growth. A prognostic model comprising these genetic alterations outperformed current established methods: cell of origin, the International Prognostic Index comprising clinical variables, and dual MYC and BCL2 expression. These results comprehensively define the genetic drivers and their functional roles in DLBCL to identify new therapeutic opportunities in the disease.

Lack of topoisomerase copy number changes in patients with de novo and relapsed diffuse large B-cell lymphoma.

Topoisomerase (TOP) gene copy number changes may predict response to treatment with TOP-targeting drugs in cancer treatment. This was first described in patients with breast cancer and is currently being investigated in other malignant diseases. TOP-targeting drugs may induce TOP gene copy number changes at relapse, with possible implications for relapse therapy efficacy. TOP gene alterations in lymphoma are poorly investigated. In this study, TOP1 and TOP2A gene alterations were investigated in patients with de novo diffuse large B-cell lymphoma (DLBCL) (n = 33) and relapsed DLBCL treated with chemotherapy regimens including TOP2-targeting drugs (n = 16). No TOP1 or TOP2A copy number changes were found. Polysomy of chromosomes 20 and 17 was seen in 3 of 25 patients (12%) and 2 of 32 patients (6%) with de novo DLBCL. Among relapsed patients, chromosome polysomy was more frequently observed in 5 of 13 patients (38%) and 4 of 16 patients (25%) harboring chromosome 20 and 17 polysomy, respectively; however, these differences only tended to be significant (p = 0.09 and p = 0.09, respectively). The results suggest that TOP gene copy number changes are very infrequent in DLBCL and not likely induced by TOP2-targeting drugs. Increased polyploidy of chromosomes 17 and 20 among patients with relapsed DLBCL may reflect genetic compensation in the tumor cells after TOP2 inhibition, but is more likely due to the increased genetic instability often seen in progressed cancers. Therefore, it is unlikely that TOP1 and TOP2A gene alterations can be used as predictive markers for response to treatment with TOP2-targeting drugs in patients with DLBCL.

A population-based study of prognosis in advanced stage follicular lymphoma managed by watch and wait.

Watch and wait (WAW) is a common approach for asymptomatic, advanced stage follicular lymphoma (FL), but single-agent rituximab is an alternative for these patients. In this nationwide study we describe the outcome of patients selected for WAW. A cohort of 286 out of 849 (34%) stage III-IVA FL patients seen between 2000 and 2011, were managed expectantly and included. The 5-year progression-free survival (PFS) was 35% [95% confidence interval (CI) 29-42]. The 10-year overall survival (OS) was 65% (95%CI 54-78), and the cumulative risk of dying from lymphoma within 10 years of diagnosis was 13% (95%CI 7-20). Elevated lactate dehydrogenase and > four nodal regions involved were associated with a higher risk of lymphoma treatment and death from lymphoma. The WAW patients and a matched background population had similar OS during the first 50 months after diagnosis (P = 0·7), but WAW patients had increased risk of death after 50 months (P < 0·001). The estimated loss of residual life after 10 years was 6·8 months. The 10-year cumulative risk of histological transformation was 22% (95%CI 15-29) and the 3-year OS after transformation was 71% (95%CI 58-87%). In conclusion, advanced stage FL managed by WAW had a favourable outcome and abandoning this strategy could lead to overtreatment in some patients.

A clinically based prognostic index for diffuse large B-cell lymphoma with a cut-off at 70 years of age significantly improves prognostic stratification: population-based analysis from the Danish Lymphoma Registry.

The introduction of rituximab and generally improved health among elderly patients have increased the survival of patients with diffuse large B-cell lymphoma (DLBCL). The International Prognostic Index (IPI) from 1992 is based on pre-rituximab data from clinical trials including several lymphoma subtypes. We applied IPI factors to a population-based rituximab-treated cohort of 1990 patients diagnosed 2000-2010 and explored new factors and the optimal prognostic age cut-off for DLBCL. Multivariate-analyses (MVA) confirmed the prognostic value of all IPI factors except the presence of > 1 extranodal lesion. The optimal age cut-off was 70 years. In a MVA of albumin, lymphocyte count, sex, immunoglobulin G, bulky disease, hemoglobin and B-symptoms, only albumin was prognostic. We propose: (1) a modified DLBCL prognostic index (DLBCL-PI) including: age (70 years), performance status (PS), lactate dehydrogenase (LDH), stage and albumin level, and (2) a separate age-adjusted DLBCL-PI for patients ≤ 70 years including PS, LDH, albumin level and > 1 extranodal lesion, however excluding stage.

Cell of origin predicts outcome to treatment with etoposide-containing chemotherapy in young patients with high-risk diffuse large B-cell lymphoma.

Addition of etoposide to the R-CHOP chemotherapy regimen with cyclophosphamide, doxorubicin, vincristine, prednisone and rituximab (R-CHOEP) has resulted in improved survival in young patients with high-risk diffuse large B-cell lymphoma (DLBCL). It is not known whether biological factors can predict this effect. In this study, 245 patients representing all young patients with high-risk DLBCL treated with R-CHOP or R-CHOEP in 2004-2012 in Denmark were extracted from the Danish lymphoma database. Patients were stratified according to cell of origin (COO) into germinal-center B-cell-like (GCB) or non-GCB by Hans' algorithm. Only in patients with the GCB phenotype was treatment with R-CHOEP associated with improved progression-free survival (PFS) and overall survival (OS) compared with R-CHOP. Patients with GCB phenotype treated with R-CHOEP also had superior OS compared with patients with non-GCB phenotype treated with R-CHOEP. This was not seen in R-CHOP treated patients. This could suggest that R-CHOEP should be restricted to patients with GCB phenotype.

MYC translocation partner gene determines survival of patients with large B-cell lymphoma with MYC- or double-hit MYC/BCL2 translocations.

In large B-cell lymphoma (LBCL) MYC- and MYC/BCL2 double-hit (DH) translocations have been associated with inferior survival. We hypothesised that the negative prognostic impact of MYC translocation was determined by an immunoglobulin MYC translocation partner gene (IG-MYC), as opposed to a non-immunoglobulin partner gene (nonIG-MYC). In a prospective, unselected cohort of 237 LBCL patients MYC and BCL2 translocations were identified by fluorescent in situ hybridisation (FISH) with split probes. MYC translocation partner gene was identified by IGH/MYC fusion probes and/or kappa/lambda split probes. Clinical data were collected from patient files. MYC translocation was identified in 28/225 patients. IG-MYC translocation partner gene was identified in 12/24 patients. DH translocation was identified in 23/228 patients. IG-MYC translocation partner gene was identified in 9/19 DH patients. Neither MYC-nor DH translocation showed correlation with survival. However, MYC translocation with IG-MYC translocation partner gene was associated with worse OS compared with both MYC translocation with nonIG-MYC translocation partner gene (P = 0.02) as well as absence of MYC translocation (P = 0.03). In patients with DH a similar, however, stronger correlation was seen (P = 0.003 and P = 0.0004 respectively). MYC - or DH translocation with nonIG-MYC translocation partner gene was not associated with worse overall survival (P = 0.2 and P = 0.3 respectively). Most patients received Rituximab (86%) and CHOP/CHOP-like chemotherapy regimes (81%). We suggest that prognostic stratification of LBCL patients by MYC and/or DH translocations should include identification of MYC translocation partner gene because approximately half of the cases harbour nonIG-MYC translocation partner genes with no or minor influence on survival.

Double-hit BCL2/MYC translocations in a consecutive cohort of patients with large B-cell lymphoma - a single centre's experience.

Concurrent BCL2 and MYC translocations, so called double hit (DH), are a rare finding in large B-cell lymphoma (LBCL). Based on data from retrospective series, DH has been correlated with aggressive clinical behaviour and poor outcome. We conducted a consecutive study of DH incidence and correlation with pathologic and clinical characteristics, including response to Rituximab-containing chemotherapy and survival, in an unselected cohort of patients with LBCL. Translocations involving BCL2 and MYC loci were examined with fluorescent in situ hybridization (FISH) in 157 patients with diffuse large B-cell lymphoma (DLBCL) or B-cell lymphoma, unclassifiable, with features intermediate between diffuse large B-cell lymphoma and Burkitt lymphoma (BCLU). The incidence of DH was 11% in the total cohort, 7% of primary LBCL and 21% of transformed LBCL. DH lymphomas were all GCB immunophenotype and were more often BCLU. No clinical characteristics were correlated with the presence of DH, which also had no impact on overall response rate (ORR), relapse rate or overall survival (OS). However, sub-stratification of DH lymphomas by FISH indicated a possible inferior survival related to immunoglobulin MYC translocation partner gene. Screening of patients with BCLU and DLBCL of GCB type for DH BCL2/MYC translocation including MYC translocation partner gene may provide important prognostic information.

Improved survival of multiple myeloma patients with late relapse after high-dose treatment and stem cell support, a population-based study of 348 patients in Denmark in 1994-2004.

OBJECTIVE: To analyse if patients with early relapse after high-dose chemotherapy with stem cell support (HDT) benefit from new treatment strategies in a population-based setting. METHODS: We conducted a retrospective study of relapse treatment and survival in 348 patients undergoing HDT in Denmark in 1994-2004. Patients were divided into two groups according to time-to-treatment failure (i) within 18 months after HDT and (ii) later than 18 months after HDT. The fraction of patients surviving 3 yr after first relapse was evaluated in relation to calendar periods for introduction of new drugs: before the introduction of thalidomide (1995-1999), before the introduction of bortezomib and lenalidomide (2000-2002) and when patients had access to all treatment modalities (2003-2008). RESULTS: Two hundred and forty-three patients suffered from relapse which required treatment. The median follow-up time was 91.4 months (60-158.8 months) and overall survival was 56.3 months after HDT. The fraction of patients alive 3 yr after first relapse increased in the periods after the year 2000 for patients with late relapse: 1995-1999, 36%; 2000-2002, 57%; and 2003-2008, 72% (P = 0.03), in contrast to patients with early relapse: 1995-1999, 25%; 2000-2002, 33%; and 2003-2008, 31% (P = 0.7). CONCLUSION: Improved survival was only observed among patients with late relapse after HDT and this may be because of increased use of salvage HDT, improved supportive care and introduction of new drugs.