Patients aged <65 years with peripheral T-cell lymphoma (PTCL) are treated with cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP). Although the addition of etoposide (CHOEP) and consolidation with autologous stem cell transplantation (ASCT) are preferred in some countries, randomized trials are lacking. This nationwide population-based study assessed the impact of etoposide and ASCT on overall survival (OS) among patients aged 18 to 64 years with stage II to IV anaplastic large-cell lymphoma (ALCL), angioimmunoblastic T-cell lymphoma (AITL), or PTCL not otherwise specified (NOS) diagnosed between 1989 and 2018 using the Netherlands Cancer Registry. Patients were categorized into 2 calendar periods, representing pre- and post-eras of etoposide and ASCT, respectively. A total of 1427 patients were identified (ALCL, 35%; AITL, 21%; and PTCL NOS, 44%). OS increased from 39% in the period from 1989 to 2009 to 49% in the period of 2009 to 2018 (P < .01). Five-year OS was superior for patients treated with CHOEP vs CHOP (64% and 44%, respectively; P < .01). When adjusted for subtype, International Prognostic Index score, and ASCT, the risk of mortality was similar between the 2 groups, except for patients with ALK+ ALCL, for whom the risk of mortality was 6.3 times higher when treated with CHOP vs CHOEP. Patients undergoing consolidation with ASCT had superior 5-year OS of 81% compared with 39% for patients not undergoing ASCT (P < .01), regardless of whether complete remission was achieved. In patients aged <65 years with advanced-stage ALK− ALCL, AITL, or PTCL, the use of ASCT consolidation, but not the addition of etoposide, was associated with improved OS.

Primary bone diffuse large B-cell lymphoma (PB-DLBCL) is a rare extranodal lymphoma subtype. This retrospective study elucidates the currently unknown genetic background of a large clinically well-annotated cohort of DLBCL with osseous localizations (O-DLBCL), including PB-DLBCL. 103 O-DLBCL patients were included and compared with 63 (extra)nodal non-osseous (NO)-DLBCLs with germinal center B-cell phenotype (NO-DLBCL-GCB). Cell-of-origin (COO) was determined by immunohistochemistry and gene-expression-profiling (GEP) using (extended)-NanoString/Lymph2Cx. Mutational profiles were identified with targeted next-generation deep-sequencing, including 52 B-cell lymphoma-relevant genes. O-DLBCLs, including 34 PB-DLBCL, were predominantly classified as GCB-phenotype based on immunohistochemistry (74%) and NanoString analysis (88%). Unsupervised hierarchical clustering of an extended-NanoString/Lymph2Cx demonstrated significantly different GEP-clusters for PB-DLBCL as opposed to NO-DLBCL-GCB (P<0.001). Expression levels of 23 genes of two different targeted GEP-panels, indicated a centrocyte-like phenotype for PB-DLBCL, whereas NO-DLBCL-GCB showed a centroblast-like constitution. PB-DLBCL had significantly more frequent mutations in four GCB-associated genes, i.e. B2M, EZH2, IRF8, and TNFRSF14, compared to NO-DLBCL-GCB (P=0.031, P=0.010, P=0.047, and P=0.003). PB-DLBCL with its corresponding specific mutational profile were significantly associated with a superior overall survival compared to equivalent Ann Arbor limited-stage I/II NO-DLBCL-GCB (P=0.011). This study is the first to demonstrate that PB-DLBCL is characterized by a GCB-phenotype, with a centrocyte-like GEP-pattern and a GCB-associated mutational profile (both involved in immune surveillance) and a favorable prognosis. These novel biology-associated features provide evidence that PB-DLBCL represents a distinct extranodal DLBCL entity and its specific mutational landscape holds potential for targeted therapies (e.g. EZH2-inhibitors).

Studies on the efficacy of rituximab in primary CNS lymphoma (PCNSL) reported conflicting results. Our international randomized phase 3 study showed that the addition of rituximab to high-dose methotrexate, BCNU, teniposide, and prednisolone (MBVP) in PCNSL was not efficacious in the short term. Here we present long-term results after a median follow-up of 82.3 months. One hundred and ninety-nine eligible newly diagnosed, nonimmunocompromised patients with PCNSL aged 18–70 years with WHO performance status 0–3 was randomized between treatment with MBVP chemotherapy with or without rituximab, followed by high-dose cytarabine consolidation in responding patients, and reduced-dose WBRT in patients aged ≤ 60 years. Event-free survival was the primary endpoint. Overall survival rate, neurocognitive functioning (NCF), and health-related quality of life (HRQoL) were additionally assessed, with the IPCG test battery, EORTC QLQ-C30 and QLQ-BN20 questionnaires, respectively. For event-free survival, the hazard ratio was 0.85, 95% CI 0.61–1.18, P = .33. Overall survival rate at 5 years for MBVP and R-MBVP was 49% (39–59) and 53% (43–63) respectively. In total, 64 patients died in the MBVP arm and 55 in the R-MBVP arm, of which 69% were due to PCNSL. At the group level, all domains of NCF and HRQoL improved to a clinically relevant extent after treatment initiation, and remained stable thereafter up to 60 months of follow-up, except for motor speed which deteriorated between 24 and 60 months. Although fatigue improved initially, high levels persisted in the long term. Long-term follow-up confirms the lack of added value of rituximab in addition to MBVP and HD-cytarabine for PCNSL.

Central nervous system (CNS) involvement in systemic B-cell non-Hodgkin lymphoma (B-NHL) at diagnosis (sysCNS) is rare. We investigated the outcome of 21 patients with sysCNS, most commonly diffuse large B-cell lymphoma, treated with high dose methotrexate (HD-MTX) and R-CHOP. The median number of cycles of HD-MTX and R-CHOP was 4 (range 1–8) and 6 (range 0–8), respectively. Consolidative whole brain radiotherapy (WBRT) was given to 33% (7/21) patients. With a median follow-up of 44 months the 3-year progression free survival (PFS) and overall survival (OS) were 45% (95%CI 34–56%) and 49% (95%CI 38–60%), respectively. Over 90% of patients had an unfavorable international prognostic index score, reflected by treatment-related mortality of 19% (4/21) and relapse-related mortality of 28% (6/21). The outcome of these patients was, however, unexpectedly good when compared to secondary CNS relapses. Prospective studies are needed to define the optimal treatment for patients with sysCNS, but its rarity might be challenging.

Genomically unstable cancers are dependent on specific cell cycle checkpoints to maintain viability and prevent apoptosis. The cell cycle checkpoint protein WEE1 is highly expressed in genomically unstable cancers, including diffuse large B-cell lymphoma (DLBCL). Although WEE1 inhibition effectively induces apoptosis in cancer cells, the effect of WEE1 inhibition on anti-apoptotic dependency is not well understood. We show that inhibition of WEE1 by AZD1775 induces DNA damage and pre-mitotic entry in DLBCL, thereby enhancing dependency on BCL-2 and/or MCL-1. Combining AZD1775 with anti-apoptotic inhibitors such as venetoclax (BCL-2i) or S63845 (MCL-1i) enhanced sensitivity in a cell-specific manner. In addition, we demonstrate that both G2/M cell cycle arrest and DNA damage induction put a similar stress on DLBCL cells, thereby enhancing anti-apoptotic dependency. Therefore, genotoxic or cell cycle disrupting agents combined with specific anti-apoptotic inhibitors may be very effective in genomic unstable cancers such as DLBCL and therefore warrants further clinical evaluation.

Current genomic models in diffuse large B-cell lymphoma (DLBCL) are based on single tumor biopsies, which might underestimate heterogeneity. Data on mutational evolution largely remains unknown. An exploratory study using whole exome sequencing on paired (primary and relapse) formalin fixed paraffin embedded DLBCL biopsies (n = 14) of 6 patients was performed to globally assess the mutational evolution and to identify gene mutations specific for relapse samples from patients treated with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone. A minority of the mutations detected in the primary sample (median 7.6%, range 4.8–66.2%) could not be detected in the matching relapse sample. Relapsed DLBCL samples showed a mild increase of mutations (median 12.5%, range 9.4–87.6%) as compared to primary tumor biopsies. We identified 264 genes possibly related to therapy resistance, including tyrosine kinases (n = 18), (transmembrane) glycoproteins (n = 73), and genes involved in the JAK-STAT pathway (n = 7). Among the potentially resistance related genes were PIM1, SOCS1, and MYC, which have been reported to convey a risk for treatment failure. In conclusion, we show modest temporal heterogeneity between paired tumor samples with the acquisition of new mutations and identification of genes possibly related to therapy resistance. The mutational evolution could have implications for treatment decisions and development of novel targeted drugs.