COMPARISON BETWEEN SINGLE-DOSE AND DIVIDED-DOSE ADMINISTRATION OF DACTINOMYCIN AND DOXORUBICIN FOR PATIENTS WITH WILMS-TUMOR - A REPORT FROM THE NATIONAL WILMS-TUMOR STUDY-GROUP

Purpose: The National Wilms' Tumor Study (NWTS)-4 was designed to eval uate the efficacy toxicity, and cost of administration of different re gimens for the treatment of Wilms' tumor (WT). Patients and Methods: B etween August 6, 1986 and September 1, 1994, 1,687 previously untreate d children less than 16 years of age with stages I to II/favorable his tology (FH) or stage I/anaplastic histology WT (low-risk [LR] group) o r stages III to N/FH WT or stages I to IV/clear cell sarcoma of the ki dney (high-risk [HR] group) were randomized to treatment that included vincristine and either divided-dose (standard [STD]) courses (5 days) or single dose (pulse-intensive [PI]) treatment with dactinomycin. HR patients also received either STD courses (3 days) or PI treatment wi th doxorubicin. Results: The 2-year relapse-free survival (RFS) rates for LR patients were 91.3% for 544 randomized to treatment with PI and 91.4% for 556 randomized to treatment with STD chemotherapy (P = .988 ). The 2-year RFS rates for HR Patients were 87.3% for 299 randomized to treatment with PI and 90.0% for 288 randomized to treatment with ST D chemotherapy (P = .865). Conclusion: We conclude that patients treat ed with PI combination chemotherapy for LR or HR WT or clear cell sarc oma of the kidney have equivalent 2-year RFS to those treated with STD regimens. PI drug administration is recommended as the new standard b ased on demonstrated efficacy, greater administered dose-intensity, le ss severe hematologic toxicity, and the requirement for fewer physicia n and hospital encounters. (C) 1998 by American Society of Clinical On cology.