PATIENT CHARACTERISTICS: Age: Over 18 Performance status: ECOG 0-1 Life expectancy: At least 3 months Hematopoietic: WBC greater than 4,000/mm3 Platelet count greater than 100,000/mm3 Hepatic: Bilirubin less than 1.5 mg/dL SGOT and SGPT less than 2 times normal Renal: Creatinine less than 1.5 mg/dL Other: No concurrent active infection No prior malignancy except squamous or basal cell carcinoma of the skin or carcinoma in situ of the cervix Not pregnant or nursing Effective contraception required of all fertile patients