PATIENT CHARACTERISTICS: Age: 18 and over Performance status: SWOG 0-1 Life expectancy: Not specified Hematopoietic: Not specified Hepatic: Not specified Renal: Creatinine no greater than 2 times upper limit of normal AND Creatinine clearance at least 50 mL/min Other: No prior malignancy in the past 5 years except adequately treated basal cell or squamous cell skin cancer, carcinoma in situ of the cervix, or adequately treated stage I or II cancer from which the patient is currently in complete remission Not pregnant or nursing Effective contraception required of all fertile patients