BCL2 Expression Is a Prognostic Marker for the Activated B-Cell-Like Type of Diffuse Large B-Cell Lymphoma.

Diffuse large B-cell lymphoma (DLBCL) is heterogeneous both clinically and morphologically reflecting a mixture of underlying biologic or genetic differences. Therefore, it is important to identify at diagnosis biological markers which permit determination of subgroups with favorable or unfavorable evolution. The goal of this study was to evaluate the impact of BCL-2 tumor expression on overall survival (OS) in germinal center B-cell (GCB) and non-GCB subgroup.

Patients and Methods. Seventy-four untreated pts (median age: 58 yrs: 36M/34F) with DLBCL de novo diagnosed in a single institution, treated with CHOP-like regimens. Tissue microarrays (TMA) blocks were created from paraffin-embedded, formalin-fixed block and stained with antibodies to CD20 (clone L26, Dako), CD10 (clone 56C6; Novocastra; NCL-CD10–270), BCL-6 (clone GI 191E/A8; Cell Mark; CMC 798) and MUM1 (clone MUM1p; Dako, CA; M7259).

Results. Tumor expression of BCL-2 (cut off 10%), by TMA, was seen in 47.3% (35/74) and was associated with a worse OS (44.7%) (p=0.038). There was no significant correlation between BCL-2 protein expression and OS (p=0.587) OS (p=0.587), whereas for the group non-GCB was associated with a worse OS (p = 0.017).

Conclusion: The immunohistochemical expression of BCL- 2 are able to identify for the GCB and non-GCB subtypes of DLBCL outcome.