PATIENT CHARACTERISTICS: Age: 18 and over Performance status: SWOG 0-2 Hematopoietic: WBC at least 4,000/mm3 Absolute granulocyte count at least 2,000/mm3 Platelet count at least 150,000/mm3 Prothrombin time and partial thromboplastin time no greater than upper limit of normal (ULN) Hepatic: SGOT and alkaline phosphatase no greater than 2 times ULN Renal: Creatinine clearance at least 50 mL/min Serum creatinine no greater than ULN Other: No second malignancy within 5 years except adequately treated basal cell or squamous cell carcinoma of the skin,in situ carcinoma of the cervix, or other cancer for which patient has been disease free for 5 years Not pregnant or nursing Effective contraception required of fertile patients