T-cell/histiocyte-rich large B-cell lymphomas and classical diffuse large B-cell lymphomas have similar outcome after chemotherapy: a matched-control analysis.

PURPOSE: Because it is unclear whether T-cell/histiocyte-rich large B-cell lymphomas (H/TCRBCL) should be considered as a true clinicopathologic entity, we conducted a matched-control analysis comparing patients with H/TCRBCL and patients with diffuse large-B cell lymphoma (B-DLCL). PATIENTS AND METHODS: More than 4,500 patients were enrolled onto non-Hodgkin's lymphoma trials conducted by the Groupe d'Etude des Lymphomes de l'Adulte. After histologic review, 50 patients were subclassified as H/TCRBCL. They were matched to 150 patients with B-DLCL for each of the factors of the International Prognostic Index (IPI).
RESULTS: Clinical characteristics of H/TCRBCL patients showed a male predominance and a median age of 47 years. Performance status was normal in 89% of patients, whereas lactate dehydrogenase level was increased in 60% of patients. The disease was disseminated in 81% of patients, and 48% had two or more involved extranodal sites. The IPI score was >or= 2 in 53% of patients. The complete response rate to chemotherapy was 63%, and 5-year overall survival (OS) and event-free survival (EFS) rates (mean +/- SD) were 58% +/- 18% and 53% +/- 16%, respectively. The matched-control analysis showed a trend toward a better response to chemotherapy for patients with B-DLCL (P =.06), whereas no difference was observed in OS (P =.9) and EFS (P =.8).
CONCLUSION: H/TCRBCL is an aggressive disease that often presents with adverse prognostic factors. However, when treatment is adapted to the disease risk, outcome is equivalent to that observed in patients with B-DLCL. Thus H/TCRBCL should be considered a pathologic variant that belongs to the B-DLCL category.