Combination Chemotherapy Plus Radiation Therapy in Treating Patients With Metastatic Rhabdomyosarcoma or Sarcoma

DISEASE CHARACTERISTICS:

* Histologically confirmed metastatic stage IV/clinical group IV rhabdomyosarcoma, undifferentiated sarcoma, or ectomesenchymoma

  * No metastatic embryonal tumors in patients under 10 years of age, regardless of primary site
  * Metastatic tumors of parameningeal sites eligible
* Bidimensionally measurable disease
* No positive cerebrospinal fluid cytology or multiple intracranial metastases
* Patients presenting with the following are only eligible for continuation therapy and may not receive irinotecan/vincristine upfront window therapy:

  * Evidence of base of skull erosion or skull metastatic disease that displaces or indents the dura, compresses the brain parenchyma, or causes evidence of cranial nerve palsy
  * Tumor that touches or displaces the spinal cord
  * Evidence of intracranial primary tumor extension
  * Tumors that could cause potentially life-threatening complications (e.g., renal, airway) with progression due to location and/or growth rate
  * Requires emergency radiotherapy
  * Lab values are consistent with disseminated intravascular coagulation

PATIENT CHARACTERISTICS:

Age:

* Under 50 (alveolar rhabdomyosarcoma, undifferentiated sarcoma, and ectomesenchymoma patients)
* 10 to 49 (embryonal histology patients)

Performance status:

* Not specified

Life expectancy:

* Not specified

Hematopoietic:

* See Disease Characteristics
* Absolute neutrophil count greater than 1,000/mm\^3\*
* Platelet count greater than 150,000/mm\^3\* NOTE: \*Unless there is tumor involvement of bone marrow

Hepatic:

* Bilirubin less than 1.5 mg/dL
* PT, PTT, and fibrinogen less than 1.5 times upper limit of normal

Renal:

* Creatinine less than 1.2 mg/dL

Other:

* Not pregnant or nursing
* Fertile patients must use effective contraception

PRIOR CONCURRENT THERAPY:

Biologic therapy:

* Not specified

Chemotherapy:

* No prior chemotherapy

Endocrine therapy:

* Prior steroids allowed

Radiotherapy:

* See Disease Characteristics
* No prior radiotherapy

Surgery:

* No more than 42 days since prior initial surgical procedure, including biopsy for diagnosis