The Predictive Role of Germinal Center or Non-Germinal Center Phenotypes in Diffuse Large B-Cell Lymphoma Patients Receiving CHOP or R-CHOP

Diffuse large B-cell lymphoma (DLBCL) is the most common type of non-Hodgkin’s lymphoma. It can be divided into the germinal center (GC) and non-GC subtypes by immunohistochemistry based on the expression of CD10, Bcl-6 and MUM-1. The GC Subtype had a significantly better survival rate than the non-GC subtype. These subtypes are predictors of outcome in DLBCL patients receiving CHOP (cyclophosphamide, adriamycin, vincristine and prednisone). Recently a significant improvement of outcome has been obtained by combining a monoclonal anti-CD20 antibody, Rituximab, with chemotherapy. We conducted the retrospective study to evaluate the predictive role of GC or non-GC subtypes in DLBCL patients receiving CHOP or rituximab-CHOP (R-CHOP). We searched the DLBCL patients diagnosed at Daegu Catholic University Hospital between 2000 and 2007. Rituximab was introduced into the treatment since 2003. Both the immunohistochemical and clinical data could be analyzed in forty six patients. According to the expression of CD10, Bcl-6 and MUM-1, we divided DLBCLs into the GC or non-GC subgroups (Blood. 2004;103:275-282). The median follow-up duration was 22.5 months. 21 and 25 patients were received CHOP and R-CHOP, respectively. 12 and 34 patients were classified into the GC and non-GC subgroups. The GC subtype showed a better overall survival (OS) than the non-GC subtype (p=0.046), but not progression-free survival (PFS) (p=0.633). The GC subtype did not predict the outcome in CHOP and R-CHOP group, respectively. In R-CHOP group, the expression of Bcl-6 was associated with a better OS (p=0.033). The GC subtype showed a better OS in low IPI (IPI 0–2) with borderline significance (p=0.054), but not in high IPI group (IPI 3–5) (p=0.429). In conclusion, the GC subtype showed a better OS in whole patients group, but didn’t show the superior outcome than the non-GC subtype in CHOP subgroup or R-CHOP subgroup, respectively, in this study. It may be due to the small size of the GC subtype. The prospective, large scale study is recommended.