Prognostic impact of CD5 expression in diffuse large B-cell lymphoma in patients treated with rituximab-EPOCH.

OBJECTIVES: CD5-positive (CD5+) diffuse large B-cell lymphoma (DLBCL) represents 5%-10% of all DLBCL cases, which has been associated with a poorer prognosis in patients treated with R-CHOP. Prognostic impact of CD5 expression in patients with DLBCL treated with R-EPOCH has not been evaluated.

METHODS: We studied 130 patients with de novo DLBCL who received frontline R-EPOCH therapy. The clinicopathologic features and overall survival (OS) were compared between patients with CD5+ and CD5- DLBCL. MYC, BCL2, and BCL6 rearrangements were examined by fluorescent in situ hybridization.

RESULTS: Sixteen (12.3%) of 130 DLBCLs were CD5+. Most clinicopathologic features including cell of origin and frequency of MYC, BCL2, and BCL6 rearrangements were similar between CD5+ and CD5- groups. Patients with CD5+ DLBCL, however, showed higher rate of central nervous system relapse (33.3% vs 15.6%; P<.01) and a higher Ki67 proliferative index compared with CD5- patients. The median OS was significantly worse in CD5+ than CD5- patients (28.13 months vs not reached, P=.006). CD5 expression was an independent prognostic factor for OS in multivariate analysis.

CONCLUSIONS: R-EPOCH therapy does not seem to impact the known poorer prognosis of patients with de novo CD5+ DLBCL, and CD5 expression was still an independent prognostic factor in R-EPOCH-treated patients with DLBCL.