PATIENT CHARACTERISTICS: Age: 18 and over Performance status: CALGB 0-2 Life expectancy: Not specified Hematopoietic: WBC at least 3500/mm3 Absolute neutrophil count at least 1500/mm3 Platelet count at least 100,000/mm3 (no platelet transfusion within 7 days) Hemoglobin at least 9 g/dL Hepatic: Total bilirubin no greater than 1.5 mg/dL Transaminases no greater than 2.5 times upper limit of normal (ULN) (no greater than 5 times ULN if liver metastases) Renal: Creatinine no greater than 1.5 mg/dL OR Creatinine clearance at least 60 mL/min Other: Not pregnant or nursing Negative pregnancy test Fertile patients must use effective contraception No concurrent uncontrolled medical or psychiatric condition No active uncontrolled infection No prior malignant disease within the past 5 years except curatively treated non-melanoma skin cancer and carcinoma in situ of the cervix