APO therapy for malignant lymphoma of large cell "histiocytic" type of childhood: analysis of treatment results for 29 patients.

Twenty-nine patients with biopsy-proven malignant lymphoma of large-cell "histiocytic" type were treated with the APO protocol (vincristine, adriamycin, and prednisone). Treatment consisted of two years of therapy with a modified adriamycin-containing acute lymphoblastic leukemia regimen with preventive cranial irradiation and regional radiotherapy (for patients with clinically localized lymphoma). The median age was 13 years (range, two to 20 years). Thirteen patients had localized disease (stage I, II), and 16 had disseminated disease (stage III, IV). The median follow-up is four years (range, seven months to nine years), and Kaplan-Meier estimates of overall and relapse-free survival are 83% and 76%, respectively. No recurrences have been observed in primary or bulk sites of lymphoma in the group of children treated with chemotherapy only. We conclude that the APO protocol, which was modeled after an acute lymphoblastic leukemia regimen, combined with regional radiotherapy can produce long-term remissions for children with malignant lymphoma of large cell "histiocytic" type.