PATIENT CHARACTERISTICS: Age: 3 to 60 Performance status: Not specified Life expectancy: Not specified Hematopoietic: Granulocyte count at least 500/mm3 Platelet count at least 75,000/mm3 Hemoglobin at least 8 g/dL (transfusion allowed) Hepatic: Bilirubin no greater than 1.5 mg/dL SGOT or SGPT no greater than 3 times normal Renal: BUN less than 30 mg/dL Creatinine no greater than 1.5 times normal for age OR Creatinine clearance at least 70 mL/min Cardiovascular: Ejection fraction at least 50% OR Fractional shortening at least 29% Other: Not pregnant or nursing Fertile patients must use effective contraception