VAC and VAI or VIE with surgery (with or without RT), are equally effective for patients with local or regional rhabdomyosarcoma and are more effective for embryonal tumors than therapies used previously. Younger patients with group 1 paratesticular embryonal tumors and all patients with group 1/2 orbit or eyelid tumors can usually be cured with VA chemotherapy along with postoperative RT for group 2 disease.

The results of treatment of 686, previously untreated patients younger than 21 years with rhabdomyosarcoma or undifferentiated sarcoma, who were entered on Intergroup Rhabdomyosarcoma Study-I (IRS-I) were analyzed after a minimum potential follow-up time of 7 years. Patients in Clinical Group I (localized disease, completely resected) were randomized to receive either vincristine, dactinomycin, and cyclophosphamide (VAC) or VAC + radiation. At 5 years, approximately 80% of patients given either treatment were still disease-free and there was no significant difference between treatments in the overall percentages of patients surviving of 93% and 81%, respectively (P = 0.67). Patients in Clinical Group II (regional disease, grossly resected) were randomized to receive either vincristine and dactinomycin (VA) + radiation or VAC + radiation. At 5 years, 72% and 65% of the patients, respectively, were disease-free and there was no evidence of a difference between treatments (P = 0.46). The overall survival percentage at 5 years was approximately 72% for both treatments. Patients in Clinical Groups III (gross residual disease after surgery) and IV (metastatic disease) were randomized to receive either "pulse" VAC + radiation or "pulse" VAC + Adriamycin (doxorubicin) + radiation. The complete remission (CR) rate was 69% in Clinical Group III and 50% in IV, with no statistically significant difference in CR rates between treatments in either group. Those who achieved a CR had a nearly 60% chance of staying in remission for 5 years in Clinical Group III compared with approximately 30% in Clinical Group IV. The overall survival percentage at 5 years was 52% in Clinical Group III compared to 20% in Clinical Group IV (P less than 0.0001). The 5-year survival percentage for the entire cohort of 686 patients was 55%. Survival after relapse was poor, being 32% at 1 year and 17% at 2 years. The risk of distant metastasis was much greater than the risk of local recurrence within each clinical group, and there was no evidence of differing types of relapses between treatments. Primary tumors of the orbit and genitourinary tract carried the best prognosis, whereas tumors of the retroperitoneum had the worst prognosis. The authors conclude that for the therapeutic regimens evaluated there was no therapeutic advantage to including radiation in the treatment of Clinical Group I disease, or cyclophosphamide given as a daily low-dose oral regimen in the treatment of Clinical Group II disease or Adriamycin in the treatment of Clinical Groups III and IV diseases.

Children with group IV RMS treated on the IRS-IV study had improved OS and FFS if they had two or fewer metastatic sites and embryonal histology. This favorable subset of patients has outcomes approaching those observed in selected patients with localized, nonmetastatic disease. Thus, these patients might not be appropriate candidates for regimens that include experimental agents with substantial toxicities or unproven antitumor activity.