PATIENT CHARACTERISTICS: Age: Not specified Performance status: ECOG 0-2 Life expectancy: At least 270 days Hematopoietic: WBC greater than 3,000/mm3 Granulocyte count greater than 1,000/mm3 Platelet count greater than 100,000/mm3 Hepatic: Bilirubin, alkaline phosphatase, and SGOT no greater than 2 times upper limit of normal (ULN) Renal: Creatinine less than 2.0 mg/dL Creatinine clearance greater than 50 mL/min Cardiovascular: No serious cardiovascular disease that would preclude study Other: No prior or concurrent malignancy within past 5 years except nonmelanoma skin cancer No serious chronic medical illness that would preclude study No acute or chronic unresolved infection Not pregnant