for the Brazilian Wilms' Tumor Study Group$ Background. To verify the adequacy of a simplified chemotherapeutic regimen for the treatment of Wilms' tumor (WT), the authors conducted a clinical trial to compare the standard fractionated dose (15 mcg/kg x 5 days) of dactinomycin (AMD) with a single dose (60 mcg/kg x 1 day] administration of the drug.
Methods. From October 1986 to December 1988, 176 WT patients were enrolled in a randomized, multicentric clinical trial conducted by the Brazilian WT Study Group in 38 institutions from 8 states. Patients were randomly assigned to treatment a r m A (standard 5-day fractionated AMD administration) or a r m B (single high dose AMD administration) in the schedules most appropriate for their stage and histology. Except for the differences in AMD administration, patients were managed by the Third U S . National WT Study protocol. The endpoints of interest were relapse free and overall survival. Complete followup information was obtained until December 1992.
Results. After a median follow-up of 47 months, there were no significant differences in survival distributions between treatment arms, using data for all patients or data stratified by disease stage. Relapse free and overall From the 'Department of Pediatric Oncology, Hospital A.C. Camargo, Sao Paulo, Brazil, and the tDepartments of Epidemiology and