Multimodal therapy for the management of primary, nonmetastatic Ewing's sarcoma of bone: a long-term follow-up of the First Intergroup study. A total of 342 previously untreated eligible children were entered into the first Intergroup Ewing's Sarcoma Study (IESS) between May 1973 and November 1978. In group I institutions, patients were randomized between treatment 1 (radiotherapy to primary lesion plus cyclophosphamide, vincristine, dactinomycin, and Adriamycin [doxorubicin; Adria Laboratories, Columbus, OH] [VAC plus ADR]) or treatment 2 (same as treatment 1 without ADR), and group II institutions randomized patients between treatment 2 or treatment 3 (same as treatment 2 plus bilateral pulmonary radiotherapy [VAC plus BPR]). The percentages of patients relapse-free and surviving (RFS) at 5 years for treatments 1, 2, and 3 were 60%, 24%, and 44%, respectively. There was strong statistical evidence of a significant advantage in RFS for treatment 1 (VAC plus ADR) versus 2 (VAC alone) (P less than .001) and 3 (P less than .05) and also of treatment 3 versus 2 (P less than .001). Similar significant results were observed with respect to overall survival. Patients with disease at pelvic sites have significantly poorer survival at 5 years than those with disease at nonpelvic sites (34% v 57%; P less than .001). Among pelvic cases, there was no evidence of differing survival by treatment (P = .81), but among nonpelvic cases, there was strong evidence of differing survival by treatment (P less than .001). The overall percentage of patients developing metastatic disease was 44%; the percentages by treatments 1, 2, and 3 were 30%, 72%, and 42%, respectively. The overall incidence of local recurrence was 15%, and there was no evidence that local recurrence rate differed by treatment. Patient characteristics related to prognosis, both with respect to RFS and overall survival experience, were primary site (nonpelvic patients were most favorable) and patient age (younger patients were more favorable). 