Advanced diffuse histiocytic lymphoma treated with cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) without maintenance therapy.

Thirty-one patients with stage III or IV diffuse histiocytic lymphoma were treated with cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) at 3- or 4-week intervals for at least six cycles or until two cycles after complete remission (CR) was achieved. At the completion of therapy, CR was documented by examination of sites known to previously contain disease. After documentation of CR, patients were followed without maintenance therapy. Fifteen patients (48%) achieved CR, four (13%) had equivocal lymphangiograms on restaging but were otherwise free of disease, two (6%) died of unrelated causes during therapy, two (6%) developed central nervous system lymphoma during therapy and despite peripheral remission eventually died of the CNS disease, and eight (26%) had either partial or no response. Twelve of the 15 patients achieving CR remain disease-free with no therapy for 9+ to 43+ months. Three patients relapsed at 3, 4, and 23 months after discontinuation of therapy. Three of the four patients with equivocal restaging lymphangiograms remain without progressive disease with no therapy for 10+ months. The projected median survival time for all patients is 41 months. The risks of long-term (maintenance) chemotherapy are considerable and include the induction of acute nonlymphoblastic leukemia. CHOP without maintenance therapy is able to induce long-term disease-free survival (and probable cure) in a significant number of patients with advanced diffuse histiocytic lymphoma.