Clinicopathological Features and Outcomes of EBV Positive and Negative DLBCL: A Study from the Grupo De Estudio Latinoamericano De Linfoproliferativos (GELL)

Introduction: Studies conducted in the pre-rituximab era found EBV positive diffuse large B-cell lymphoma (EBV+ DLBCL) as a disctinct entity carrying a dismal prognosis when compared with EBV negative (EBV-) DLBCL cases. However, studies evaluating this disparity in the rituximab era are lacking. Therefore, we aim to investigate the clinicopathological features and outcomes patterns among EBV+ and EBV- DLBCL managed in the modern era. Methods: We retrospectively analyzed patients 18 years and older diagnosed with DLBCL between 2006 to 2020. Seven centers from the Grupo de Estudio Latinoamericano de Linfoproliferativos (GELL) participated in the study. Hematopathologists at each participating institution reviewed the pathological samples to confirm the diagnosis of EBV+ or EBV- DLBCL, not otherwise specified (NOS). EBV infection was confirmed with a positive EBER test ≥1%. The primary endpoint was overall survival (OS), defined as the time from the date of diagnosis until death from any cause or last follow up. The secondary endpoint was progression-free survival (PFS) defined as the time from diagnosis until death, progression, or last follow up. OS and PFS probabilities were computed with the Kaplan-Meier method and compared using the log-rank test. We used Cox regression analysis to evaluate the proportional hazard ratios (HRs) of each score for our study outcomes. Outcomes with a p-value