Combination chemotherapy of diffuse histiocytic lymphoma with cyclophosphamide, adriamycin, vincristine and prednisone (CHOP).

Twenty-three patients with diffuse histiocytic lymphoma who had not had prior chemotherapy were treated with CHOP (cyclophosphamide, adriamycin, vincristine, and prednisone). Sixteen of these patients had previously been treated with radiation therapy. Nine of these 23 patients had a pathologically documented complete response at the conclusion of CHOP with an overall complete response rate of 39%. In patients whose disease was confined to lymph nodes, the complete response rate was 7 of 8 or 88%, while in patients with stage IV disease, only 2 of 15 or 13% had complete responses. Although prior radiation therapy could not be demonstrated to be an adverse prognostic factor in this small series, it could have accounted for the low overall complete response rate noted. Complete response in this series was well sustained with an actuarial relapse-free survival of 75% and an actuarial survival of 89% at two years. No complete responses occurred in five patients who had received prior chemotherapy.