Profiling of diffuse large B-cell lymphoma by immunohistochemistry: identification of prognostic subgroups.

Diffuse large B-cell lymphoma (DLBCL) is a frequent lymphoma subtype with a heterogeneous behavior and a variable response to conventional chemotherapy. This clinical diversity is believed to reflect differences in the molecular pathways leading to lymphomagenesis. In this study, we have analyzed pretreatment, diagnostic samples from 108 DLBCL by immunohistology for expression of four markers linked to germinal center B-cells (CD10, Bcl-6), postgerminal center B-cells (MUM1) and apoptosis (Bcl-2). The results indicate that both CD10 and Bcl-6 are favorable prognostic indicators, in contrast to Bcl-2, which is an adverse parameter. Furthermore, using two algorithms for distinction between low- and high-risk patients proposed by Hans et al. (Blood, 2004; 103:275) and Muris et al. (Journal of Pathology, 2006; 208:714), it is shown that both are useful for predicting outcome in DLBCL. However, in this report, the algorithm of Hans et al. was superior to that of Muris et al. These findings confirm and extend other studies and indicate that different prognostic subgroups of DLBCL can be distinguished by simple immunohistological investigations for a limited number of markers. Whether these groups are also relevant for individual treatment decisions will be important to investigate in prospective studies.