DISEASE CHARACTERISTICS: - Newly diagnosed, biopsy-confirmed metastatic rhabdomyosarcoma (RMS) or ectomesenchymoma, including the following: - Embryonal RMS (for patients 10 to 49 years of age) - Alveolar RMS or ectomesenchymoma (for patients under 50 years of age) - RMS with parameningeal and paraspinal primary tumors, including those with intracranial extension by contrast MRI showing that the primary tumor touches, displaces, invades, distorts, or otherwise causes signal abnormality of the dura in brain or spinal cord in contiguity to the primary site, are allowed - Has undergone initial surgery (including biopsy) that provided the definitive diagnosis within the past 42 days - Enrollment on COG-D9902 required PATIENT CHARACTERISTICS: - ECOG performance status (PS) 0-2 - ANC ≥ 750/μL* - Platelet count ≥ 75,000/μL* - Creatinine clearance or radioisotope GFR ≥ 70 mL/min OR maximum serum creatinine based on age/gender as follows: - 0.4 mg/dL (for patients 1 to 5 months of age) - 0.5 mg/dL (for patients 6 to 11 months of age) - 0.6 mg/dL (for patients 1 year of age) - 0.8 mg/dL (for patients 2 to 5 years of age) - 1.0 mg/dL (for patients 6 to 9 years of age) - 1.2 mg/dL (for patients 10 to 12 years of age) - 1.5 mg/dL (males) or 1.4 mg/dL (females) (for patients 13 to 15 years of age) - 1.7 mg/dL (males) or 1.4 mg/dL (females) (for patients ≥ 16 years of age) - Urinary tract obstruction by tumor allowed provided the above renal function criteria are met AND there is unimpeded urinary flow established via decompression of the obstructed portion of the urinary tract - Total bilirubin ≤ 1.5 times upper limit of normal (ULN) for age (unless there is evidence of biliary obstruction by the tumor) - Shortening fraction ≥ 27% by ECHO OR ejection fraction ≥ 50% by radionuclide angiogram - Not pregnant or nursing - Negative pregnancy test - Fertile patients must use effective contraception during and for ≥ 3 months after the last dose of cixutumumab - No uncontrolled infection - No known type I or type II diabetes mellitus (for patients enrolled in groups 1 or 3) NOTE: *Abnormal blood counts allowed provided bone marrow biopsy or aspirate confirm bone marrow involvement by RMS PRIOR CONCURRENT THERAPY: - No prior chemotherapy or radiotherapy except corticosteroids or emergent radiotherapy - No concurrent growth hormone therapy - No concurrent sargramostim