CD5 positivity is an independent adverse prognostic factor in elderly patients with diffuse large B cell lymphoma

Diffuse large B cell lymphoma (DLBCL) is the most common non-Hodgkin lymphoma. Age over 60 years is one of the five parameters of the International Prognostic Index (IPI), which is the most important clinical prognostic predictor in DLBCL. A previous study on German DLBCL patients over 60 years of age showed that immunoblastic morphology, but not germinal center B cell-like (GCB)/non-GCB subtype, correlated with short survival. We collected 174 DLBCL cases over 60 years of age in Taiwan and performed immunophenotyping and detection of Epstein-Barr virus (EBV)-encoded RNA (EBER) by in situ hybridization. Of the cases, 5.2 % were positive for CD5 and 5.7 % positive for EBER. Neither immunoblastic morphology nor GCB/non-GCB subtype correlated with survival. In univariate analysis, adverse prognostic factors included IPI ≥ 3 (P < 0.000001), B symptoms (P = 0.000075), bone marrow/peripheral blood involvement (P = 0.017), EBER positivity (P = 0.0013), and CD5 positivity (P = 0.016). In multivariate analysis, CD5 positivity was the only independent adverse prognostic factor (HR = 3.16; 95 % CI = 1.34-7.47; P = 0.0087) in addition to IPI ≥ 3 (HR = 3.07; 95 % CI = 1.84-5.11; P = 0.000018). Surprisingly, despite an overall 5.2 % incidence of central nervous system (CNS) relapse in our patients, none of the CD5+ cases experienced CNS relapse (P = 1.00). This is in stark contrast to the more frequent CNS relapse in Japanese CD5+ DLBCL patients. EBER positivity was associated with IPI ≥ 3 (P = 0.010), stage III-IV (P = 0.0082), and B symptoms (P = 0.011). In multivariate analysis, EBER positivity was not an independent adverse prognostic factor (P = 0.81), its effect being due likely to accompanying adverse clinical parameters.