Background: The development of gene expression profiling and tissue microarray techniques have provided more information about the heterogeneity of diffuse large B-cell lymphoma (DLBCL), enabling categorization of DLBCL patients into 3 prognostic groups according to cell origin (but independently from the International Prognostic Index [IPI] score): germinal center (GCB), activated B-cell (ABC), and not classified (NC) diffuse large B-cell lymphoma. This study investigated the role of immunohistochemical discrimination between GCB and ABC&NC-DLBCL subtypes in identifying those high-risk patients who may benefit from a more aggressive first-line therapeutic approach.
Methods: From February 2003 to August 2006, 45 newly diagnosed DLBCL patients, with IPI≥2, were considered eligible for this study: 13 had a GCB, 8 an ABC, and 24 a NC-DLBCL. GCB patients received 6 courses of rituximab, cyclophophosphamide, doxorubicin, vinicristine, and prednisone (R-CHOP) chemotherapy, with a subsequent, autologous stem cell transplantation in case of partial response. All ABC and NC-DLBCL patients received 6 R-CHOP cycles and autologous stem cell transplantation.
Results: Complete response rate for each treatment arm was 84.6% for GCB and 89.7% for ABC&NC-DLBCL (P = .50), with a continuous complete response rate of 81.8% and 84.6%, respectively (P = .59). Projected 4-year overall survival is 100% for GCB and 82% for ABC&NC patients (P = .12). Progression-free survival is 77% and 79% (P = .7), respectively.
Conclusions: The autologous stem cell transplantation consolidation in the ABC&NC-DLBCL subtypes induced the same rate of complete response (and similar progression-free survival rate) compared with GCB-DLBCL. In ABC&NC-DLBCL patients the authors observed a complete response rate of 89.7% vs. 84.6% in the GCB-DLBCL subset, without any significant difference in progression-free survival rate.
Copyright © 2010 American Cancer Society.