Prognostic Significance of BCL-2 and BCL-6 Expression in MYC-positive DLBCL.

BACKGROUND

Double-expression lymphoma (DEL) is a rare subgroup of diffuse large B-cell lymphoma (DLBCL), which has coexpression of MYC and BCL-2. Coexpression of MYC and BCL-2 is considered a prognostic marker portending poor outcomes. However, the prognostic effect of BCL-2 and BCL-6 expression in DLBCL remains controversial.

MATERIALS AND METHODS

Immunohistochemical staining was performed to detect MYC, BCL-2 and BCL-6 expression in 212 patients with newly diagnosed DLBCL and assess the prognostic effects of BCL-2 and BCL-6 expression. The DLBCL patients were treated with R-CHOP (rituximab plus cyclophosphamide, doxorubicin, vincristine [Oncovin], prednisone)-like regimens.

RESULTS

Retrospective analysis revealed that BCL-2 and BCL-2/MYC were prognostic factors indicative of poor outcomes. Patients with BCL-2 and/or MYC expression had a poorer prognosis than that of patients with BCL-2 and/or MYC expression. Patients with BCL-2/MYC expression showed a trend toward poorer survival than those with BCL-2/MYC expression, suggesting that BCL-2 plays a more important role than MYC. Also, patients with BCL-6/MYC expression had poorer progression-free survival than those with BCL-6/MYC expression. In addition, patients with BCL-2/MYC/BCL-6 expression had the worst prognosis, suggesting that BCL-6 is a prognostic factor for poor outcomes for MYC DLBCL patients. Altogether, our findings have shown that BCL-2 is an independent prognostic factor and possibly plays a more important role than MYC in MYC DLBCL patients. Furthermore, we found that BCL-6 expression could also be a prognostic factor portending poor outcomes for MYC DLBCL patients.