Indications for radiotherapy and chemotherapy after complete resection in rhabdomyosarcoma: A report from the intergroup rhabdomyosarcoma studies I to III

Purpose: To evaluate the outcome of patients with rhabdomyosarcoma (RMS) tr eated with complete surgical resection and multiagent chemotherapy, with or without local radiotherapy (RT), Patients and Methods: Four hundred thirty-nine patients with completely res ected (ie, group I) RMS were further treated with chemotherapy (vincristine and actinomycin D +/- cyclophosphamide, doxarubicin, and cisplatin) on Int ergroup Rhabdomyosarcoma Studies (IRS) I to III between 1972 and 1991. Eigh ty-three patients (19%) also received local PT as a component of initial tr eatment, Results: Eighty-six patients relapsed (10-year failure free survival [FFS]7 9%, overall survival 89%), Six percent of failure sites were local, 6% were regional, and 7% were distant. Poor prognostic factors were tumor size gre ater than 5 cm, alveolar or undifferentiated histology, primary tumor sites other than genitourinary, and treatment on IRS-1 or II. For patients with embryonal RMS who were treated with PT, there was a trend for improved FFS but no difference in overall survival, On IRS-l and ii, patients with alveo lar or undifferentiated sarcoma who received PT compared with those who did not receive RT herd greater 10-year FFS rates (73% v 44%, respectively; P =.03) and overall survival rates (82% v 52%, respectively;) (P =.02), Such patients who received PT on IRS III also benefited more than those who did not receive PT (10-year FFS, 95% v 69%; P =.01; overall survival, 95% v 86% ; P =.23), Conclusion: patients with group I embryonal RMS have an excellent prognosis when treated with adjuvant multiagent chemotherapy without PT. Patients wi th alveolar RMS or undifferentiated sarcoma fare worse; however, FFS and ov erall survival are substantially improved when PT is added to multiagent ch emotherapy (IRS-1 and II). The best outcome occurred in IRS-III, when PT we ts used in conjunction with intensified chemotherapy. (C) 1999 by American Society of Clinical Oncology.