A follow-up of a randomized study comparing two chemotherapy treatments for advanced diffuse histiocytic lymphoma.

In 1976 we began a randomized study for the treatment of patients with stage III and IV diffuse histiocytic lymphoma. The therapy was either ACOMLA (doxorubicin, cyclophosphamide, vincristine [oncovin], methotrexate with leucovorin rescue, and cytarabine) or CHOP-B (cyclophosphamide, doxorubicin [hydroxydaunorubicin], vincristine [oncovin], prednisone, and bleomycin). A complete response (CR) was achieved in 13 (65%) of 20 patients treated with ACOMLA and in 20 (71%) of the 28 patients treated with CHOP-B. Four patients achieving CR with ACOMLA and three patients treated with CHOP-B have relapsed for an overall relapse rate of 21%. Partial response (PR) was obtained in four patients treated with ACOMLA and five patients treated with CHOP-B. Median follow-up time is 36 months for the combined treatment groups. Multiple regression analysis demonstrated that those patients who were classified by the Lukes-Collins criteria as having histiocytic lymphoma not of follicular center-cell origin (combined T- and B-cell immunoblastic sarcoma) had a significantly worse survival as compared to patients classified with follicular center-cell origin lymphoma (large cell noncleaved, large cell cleaved, and large cell unclassified) with a 40% five-year survival versus an 80% five-year survival (P = .011). The CR rate however for these two large categories of patients was 63% v 73% respectively, and the relapse rates were equivalent. The increased survival in the follicular center-cell origin lymphomas may be related to a longer survival of PRs and relapsed patients as compared to the patients with nonfollicular center-cell lymphomas.