Combination Chemotherapy With or Without Radiation Therapy in Treating Patients With Newly Diagnosed Rhabdomyosarcoma

OBJECTIVES:

• Determine the failure-free survival (FFS) rate in patients with newly diagnosed low-risk rhabdomyosarcoma of embryonal or botryoid subtype meeting criteria for group I after treatment with dactinomycin and vincristine with or without radiotherapy.
• Determine the FFS rate in these patients meeting criteria for group II after treatment with dactinomycin, vincristine, and cyclophosphamide with or without radiotherapy.
• Determine the FFS rate in patients with ectomesenchymomas containing rhabdomyosarcomatous elements (embryonal histiotype) who receive one of the above treatments.
• Determine new molecular markers specific to embryonal and botryoid tumor histologies which are of diagnostic and prognostic significance in patients treated with these regimens.

OUTLINE: Patients are assigned to 1 of 2 groups, depending on histology and site of disease.

• Group I (favorable tumor site, negative lymph nodes, stage 1, clinical group I, IIA, or III (orbit only), node negative [N0] OR unfavorable tumor site, negative or unknown lymph nodes, stage 2, clinical group I): Patients receive vincristine IV over 1 minute weekly for 8 weeks and dactinomycin IV over 1 minute once every 3 weeks for 4 doses. Treatment repeats every 12 weeks for 4 courses. Radiotherapy is administered to patients with clinical group II or III disease on weeks 3-8.
• Group II (favorable tumor site, positive lymph nodes, stage 1, clinical group III (orbit only), node positive [N1] OR favorable tumor site except orbit, any lymph nodes, stage 1, clinical group III OR unfavorable tumor site, stage 2, clinical group II OR unfavorable tumor site, stage 3, clinical group I or II): Patients receive vincristine and dactinomycin as in group I. Patients also receive cyclophosphamide IV over 30-60 minutes and filgrastim (G-CSF) or sargramostim (GM-CSF) subcutaneously once daily beginning 24 hours after completion of chemotherapy and continuing for 10 days or until blood counts recover. Radiotherapy is administered on weeks 3-8, 12-17, or 28-33, if clinically indicated as in group I.

Patients are followed every 3-4 months for 3 years (4 years after diagnosis), every 6 months for 1 year, and then annually thereafter.

PROJECTED ACCRUAL: A total of 254 patients for group I will be accrued for this study within 6 years. Approximately 12 patients per year will be accrued for group II.