PurposeTo explore the prognostic impact and interdependence of the cell-of-origin (COO) classification, dual expression (DE) of MYC and BCL2 proteins, and MYC, BCL2, and BCL6 translocations in two prospectively randomized clinical trials of patients with diffuse large B-cell lymphoma (DLBCL).Patients and MethodsOverall, 452 formalin-fixed paraffin-embedded samples from two prospective, randomized DLBCL trials (RICOVER-60, prospective, randomized study for patients > 60 years, all IPI groups; and R-MegaCHOEP, prospective, randomized study for patients ≤ 60 years with age-adjusted IPI 2,3) of the German High-Grade Non-Hodgkin Lymphoma Study Group were analyzed with the Lymph2Cx assay for COO classification, with immunohistochemistry for MYC and BCL2, and with fluorescent in situ hybridization for MYC, BCL2, and BCL6 rearrangements.ResultsCOO classification was successful in 414 of 452 samples. No significant differences with respect to COO (activated B-cell [ABC]–like DLBCL v germinal center B-cell [GCB]–li...

https://ascopubs.org/doi/pdfdirect/10.1200/JCO.2016.70.3660

Clinical Impact of the Cell-of-Origin Classification and the MYC/BCL2 Dual Expresser Status in Diffuse Large B-Cell Lymphoma Treated Within Prospective Clinical Trials of the German High-Grade Non-Hodgkin's Lymphoma Study Group

High-grade B-cell lymphoma with MYC and BCL2 and/or BCL6 rearrangements with diffuse large B-cell lymphoma morphology

[Histopathology of non-Hodgkin's lymphomas].

Double-hit lymphoma (DHL) is a subgroup of aggressive lymphomas with both MYC and BCL2 gene rearrangements, characterised by a rapidly progressing clinical course that is refractory to aggressive treatment and short survival. Over time, the definition was modified and now includes diffuse large B-cell lymphoma (DLBCL) with MYC translocation combined with an additional translocation involving BCL2 or BCL6. Some cases that have a similar clinical course with concomitant overexpression of MYC or BCL2 proteins were recently characterised as immunohistochemical double-hit lymphomas (ie, double-protein-expression lymphomas [DPLs]). The clinical course of these DPLs is worse than so-called standard DLBCL but suggested by some studies to be slightly better than DHL, although there is overlap between the two categories. Present treatment does not allow cure or long-term survival in patients with genetic or immunohistochemical double-hit lymphomas, but several new drugs are being developed.

https://www.thelancet.com/pdfs/journals/lanonc/PIIS1470-2045(15)00005-4.pdf

Double-hit and double-protein-expression lymphomas: aggressive and refractory lymphomas

How I treat double-hit lymphoma

Prognostically relevant risk factors in patients with diffuse large B-cell lymphoma (DLBCL) have predominantly been evaluated in elderly populations. We tested whether previously described risk factors are also valid in younger, poor-prognosis DLBCL patients. Paraffin-embedded samples from 112 patients with de novo DLBCL, enrolled in the R-MegaCHOEP trial of the German High Grade Non-Hodgkin Lymphoma Study Group (DSHNHL) were investigated using immunohistochemistry (MYC, FOXP1, LMO2, GCET1, CD5, CD10, BCL2, BCL6, IRF4/MUM1) and fluorescence in situ hybridization (MYC, BCL2, BCL6). MYC, BCL2 and BCL6 breaks occurred in 14, 21 and 31%, respectively. In the majority of cases, MYC was simultaneously rearranged with BCL2 and/or BCL6. The adverse impact of MYC rearrangements was confirmed, but the sole presence of BCL2 breaks emerged as a novel prognostic marker associated with inferior overall survival (OS) (P=0.002). Combined overexpression of MYC and BCL2 showed only limited association with inferior OS. All immunohistochemical cell of origin classifiers applied failed to predict survival time. DLBCL tumors with significant proportion of immunoblastic and/or immunoblastic-plasmacytoid cells had inferior OS, independently from from BCL2 break. Younger, poor-prognosis DLBCL patients, therefore, display different biological risk factors compared with an elderly population, with BCL2 translocations emerging as a powerful negative prognostic marker.

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Different biological risk factors in young poor-prognosis and elderly patients with diffuse large B-cell lymphoma

Hintergrund
Die Detektion charakteristischer genomischer Aberrationen mittels nicht radioaktiver In-situ-Hybridisierung (ISH) hat nach den Vorschlagen der World Health Organization (WHO) eine wichtige Rolle in der Lymphomdiagnostik. Um die Reproduzierbarkeit entsprechender Analysen zu untersuchen, wurde ein Ringversuch mit acht Instituten fur Hamatopathologie durchgefuhrt.

H-W Bernd

Papers

Different biological risk factors in young poor-prognosis and elderly patients with diffuse large B-cell lymphoma

Ringversuch zum Nachweis genomischer Veränderungen bei Non-Hodgkin-Lymphomen mittels In-situ-Hybridisierung