PATIENT CHARACTERISTICS: Age: 18 and over Performance status: ECOG 0-2 Life expectancy: At least 12 weeks Hematopoietic: WBC at least 3500/mm3 Granulocyte count at least 1,500/mm3 Platelet count at least 100,000/mm3 Hepatic: Bilirubin no greater than 1.5 mg/dL SGOT and SGPT no greater than 2.5 times upper limit of normal (ULN) Alkaline phosphatase no greater than 2.5 times ULN Renal: Creatinine no greater than 1.5 mg/dL Creatinine clearance at least 60 mL/min Calcium and electrolytes normal Other: No other malignancy within past 5 years except curatively treated nonmelanoma skin cancer or carcinoma in situ of the cervix Not pregnant or nursing No active infections or other serious medical conditions