Winter JN et al. (2006) Prognostic significance of Bcl-6 protein expression in DLBCL treated with CHOP or R-CHOP: a prospective correlative study. Blood 107: 4207–4213

The addition of rituximab (R) to CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone) is a new strategy in the treatment of diffuse, large B-cell lymphomas (DLBCLs). Researchers from the US have reported that R-CHOP could potentially be limited to patients who do not express the Bcl-6 protein, a marker of germinal center origin.

Bcl-6 expression is predictive of favorable outcome in patients with DLBCL treated with conventional CHOP. Winter et al. aimed to determine whether this biomarker retains its prognostic significance with R-CHOP. Their analysis formed part of a US Intergroup trial, which randomized patients with DLBCL aged 60 years or over to receive CHOP or R-CHOP. Tissue samples from 199 patients (CHOP 46%, R-CHOP 54%) were analyzed for Bcl-6 expression.

The 2-year failure-free and overall survival rates were higher in Bcl-6-positive patients treated with CHOP than in similarly treated cases who were Bcl-6-negative. Conversely, Bcl-6 status did not affect the failure-free or overall survival of patients in the R-CHOP group. In the multivariate analysis, the relative risk of treatment failure and death from DLBCL was significantly lower for Bcl-6-negative patients treated with R-CHOP (P <0.001) than for those treated with CHOP alone. For Bcl-6-positive patients, the treatment regimen did not significantly impact the long-term outcome. The authors conclude that R-CHOP does not benefit patients over the age of 60 whose DLBCLs express Bcl-6, and that the prognostic significance of this marker is lost when the R-CHOP combination is used.