Cell of origin is not associated with outcomes of relapsed or refractory diffuse large B cell lymphoma.

Activated B cell (ABC) type diffuse large B cell lymphoma (DLBCL), double hit lymphoma (DHL) and double expressor lymphoma (DEL) have poor outcomes to frontline R‐CHOP but impact of these molecular features on outcomes of relapsed/refractory (R/R) disease is not well‐characterized. We evaluated the association of diagnostic cell of origin (COO), double hit and double expressor status with overall survival after first relapse in DLBCL patients who were enrolled into the Molecular Epidemiology Resource (MER) cohort. COO was available from immunohistochemistry (IHC) using Hans criteria or gene expression profiling (GEP) (Nanostring) on the diagnostic FFPE biopsy. Of 373 pts with R/R DLBCL, 278 had COO by IHC: 152 were GCB, 107 were non‐GCB. One hundred and fourty had COO by GEP: 44 were ABC, 65 were GCB and 13 were unclassifiable. Nineteen out of 163 (12%) were DHL; 30 out of 135 (22%) had DEL. COO, either by IHC (2 years OS GCB: 45% [CI95: 38–54] vs. non‐GCB: 44% [CI95:36–55], p > 0.05) or GEP (2 years OS ABC: 42% [CI95: 29–59] vs. GCB: 40% [CI95: 30–54], p > 0.05), was not associated with difference in OS. DHL (2 years OS 16 [CI95:6–45] vs. 45% [CI95: 34–59], p < 0.01) and DEL (2 years OS 33% [CI95: 20–56], vs. 50% [CI95: 41–60], p < 0.05) had lower OS than non‐DHL and non‐DEL/non‐DHL counterparts, respectively. COO by IHC or GEP was not associated with OS in R/R DLBCL while DHL and DEL were adverse prognostic markers in DLBCL at first relapse. [ABSTRACT FROM AUTHOR]