Rituximab combined with MACOP-B or VACOP-B and radiation therapy in primary mediastinal large B-cell lymphoma: a retrospective study.

Background: Third-generation regimens (MACOP-B [methotrexate/leucovorin (LV)/doxorubicin/cyclophosphamide/vincristine/ prednisone/bleomycin] or VACOP-B [etoposide/LV/doxorubicin/cyclophosphamide/vincristine/prednisone/bleomycin]) in combination with local radiation therapy seem to improve lymphoma-free survival of primary mediastinal large B-cell lymphoma (PMLBCL). Recently, the superiority of R-CHOP (rituximab plus cyclophosphamide/doxorubicin/vincristine/ prednisone) over CHOP-like regimens has been demonstrated in elderly and younger patients with low-risk diffuse large B-cell lymphoma.

Patients And Methods: Retrospectively, between February 2002 and July 2006, 45 previously untreated patients with PMLBCL were treated with a combination of a third-generation chemotherapy regimen (MACOP-B or VACOP-B), concurrent rituximab, and mediastinal radiation therapy.

Results: Twenty-six (62%) patients achieved a complete response (CR), and 15 (36%) obtained a partial response after MACOP-B/VACOP-B plus rituximab. After radiation therapy, the CR rate was 80%. At a median follow-up of 28 months, among the 34 patients who obtained a CR, 3 relapsed after 16, 19, and 22 months, respectively. Projected overall survival was 80% at 5 years; the relapse-free survival (RFS) curve of the 34 patients who achieved CR was 88% at 5 years.

Conclusion: In this retrospective study, in patients with PMLBCL, combined-modality treatment using the MACOP-B/VACOP-B regimen plus rituximab induces a high remission rate, with patients having a > 80% chance of surviving relapse free at 5 years. In comparison with historical data on MACOP-B/VACOP-B without rituximab, there are no statistically significant differences in terms of CR and RFS rates.