PATIENT CHARACTERISTICS: Age: 18 and over Performance Status: SWOG 0-2 Life Expectancy: Not specified Hematopoietic: Absolute granulocyte count at least 1,500/mm3 Platelet count at least 100,000/mm3 Hepatic: Bilirubin no greater than institutional upper limit of normal (ULN) SGOT no greater than 2 times ULN Renal: Creatinine no greater than institutional ULN OR creatinine clearance at least 50 mL/min Other: Not pregnant or nursing Effective contraceptive method used while on study No prior malignancies allowed, except: basal or squamous cell skin cancer in situ cervical cancer Stage I or II cancer which is in remission Any cancer from which patients have been disease free for 5 years