PATIENT CHARACTERISTICS: Age: 18 and over Performance status: ECOG 0-2 Life expectancy: Not specified Hematopoietic: WBC at least 3500/mm3 Platelet count at least 130,000/mm3 Hepatic: Bilirubin no greater than 1.5 times upper limit of normal (ULN) SGOT no greater than 2 times ULN Renal: Creatinine no greater than 0.5 mg/dL Other: Not pregnant or nursing Fertile patients must use effective contraception No uncontrolled infection No concurrent malignant disease or major medical problem except superficial skin cancers