PATIENT CHARACTERISTICS: Age: 18 and over Performance status: Not specified Life expectancy: Greater than 3 years Hematopoietic: WBC at least 3500/mm3 Platelet count at least 100,000/mm3 Hemoglobin at least 10 g/dL Hepatic: Bilirubin no greater than 1.5 times upper limit of normal (ULN) Alkaline phosphatase no greater than 3 times ULN SGOT no greater than 3 times ULN Renal: Creatinine no greater than 1.5 times ULN Other: Not pregnant or nursing Fertile patients must use effective contraception At least 5 years since prior malignancy except nonmetastatic squamous cell or basal cell carcinoma of the skin No history of drug interactions which could affect therapy No immunodeficiency