High-Dose Combination Chemotherapy and Radiation Therapy in Treating Patients With Newly Diagnosed Metastatic Rhabdomyosarcoma or Ectomesenchymoma

OBJECTIVES: Primary * Improve the early disease control interval for patients with newly diagnosed, high-risk, metastatic rhabdomyosarcoma or ectomesenchymoma using intensive, interval-compression therapy (comprising vincristine, irinotecan hydrochloride, ifosfamide, etoposide, doxorubicin hydrochloride, cyclophosphamide, and dactinomycin) that permits maximal early exposure to known effective agents. * Determine the feasibility and assess immediate- and short-term side effects of concurrent irinotecan hydrochloride and radiotherapy in these patients. Secondary * Expand the available data for response to irinotecan hydrochloride and vincristine in previously untreated patients with high-risk rhabdomyosarcoma. * Evaluate, prospectively, and validate gene expression values with the intent to define the best diagnostic predictors and more powerful prognostic classifiers. OUTLINE: This is a prospective, nonrandomized, multicenter study. Patients are stratified according to prognostic factors predictive of outcome (e.g. histology, bone/bone marrow involvement, and number of metastatic sites). Patients receive high-dose chemotherapy comprising vincristine IV over 1 minute on day 1 of weeks 1-5, 7, 8, 11, 12, 15, 16, 20-24, 28, 29, 32, 33, 35, 38, 41-44, 47, 48, 50, and 51; irinotecan hydrochloride IV over 1 hour on days 1-5 of weeks 1, 4, 20, 23, 47, and 50; and ifosfamide IV over 1 hour and etoposide IV over 30-60 minutes on days 1-5 of weeks 9, 13, 17, 26, and 30. Patients also receive doxorubicin hydrochloride IV continuously over 24 hours on days 1 and 2 of weeks 7\*, 11, 15, 28, and 32; cyclophosphamide IV over 30-60 minutes on day 1 of weeks 7, 11, 15, 28, 32, 35, 38, 41, and 44; and dactinomycin IV over 1-5 minutes on day 1 of weeks 35, 38, 41, and 44 in the absence of disease progression or unacceptable toxicity. Patients also receive filgrastim (G-CSF) subcutaneously in weeks 7-9, 11-13, 15-17, 22, 26, 28-30, 32, 33, 35, 38, and 41-44 beginning 24-36 hours after the last chemotherapy dose and continuing until blood counts recover. NOTE: \*Patients undergoing early radiotherapy for intracranial extension do not receive doxorubicin in week 7. Beginning at week 20 (or week 1 for patients with parameningeal tumors with intracranial extension \[or spinal cord compression\] requiring emergency radiotherapy), patients also undergo radiotherapy once a day, 5 days a week, for approximately 5½ weeks. Some patients may also undergo second-look surgery. After completion of study treatment, patients are followed periodically for ≥ 10 years. PROJECTED ACCRUAL: A total of 75 patients will be accrued for this study.