PATIENT CHARACTERISTICS: Age: 18 and over Performance status: ECOG 0-2 Life expectancy: At least 8 weeks Hematopoietic: Absolute neutrophil count at least 1,500/mm3 Platelet count at least 100,000/mm3 Hepatic: Bilirubin no greater than 1.5 times upper limit of normal (ULN) SGOT no greater than 3 times ULN Renal: Creatinine no greater than 1.5 times ULN OR Creatinine clearance at least 50 mL/min Cardiovascular: No active cardiac ischemia No congestive heart failure Other: No significant active infection No other severe complicating medical illness (e.g., severe neurologic or psychiatric disease that would prevent compliance) No concurrent malignancy except nonmelanoma skin cancer or carcinoma in situ of the cervix Not pregnant or nursing Fertile patients must use effective contraception