PATIENT CHARACTERISTICS: Age: 12 and over Performance status: Zubrod 0-2 Life expectancy: Not specified Hematopoietic: Not specified Hepatic: Bilirubin less than 2 mg/dL Renal: Creatinine less than 2 mg/dL Cardiovascular: No severe heart disease Other: No psychoses Not pregnant or nursing Fertile patients must use effective contraception