PATIENT CHARACTERISTICS: Age: Not specified Performance status: 0-2 Life expectancy: Not specified Hematopoietic: Not specified Hepatic: Bilirubin no greater than 1.5 mg/dL SGPT no greater than 2 times upper limit of normal Renal: Creatinine no greater than 1.5 mg/dL OR Creatinine clearance greater than 60 mL/min Other: Not pregnant or nursing Fertile patients must use effective contraception