PATIENT CHARACTERISTICS: Age: 18 and over Performance status: Zubrod 0-2 Life expectancy: At least 12 weeks Hematopoietic: WBC greater than 4,000/mm3 Granulocyte count greater than 1,500/mm3 Platelet count greater than 100,000/mm3 Hepatic: Bilirubin no greater than 1.5 mg/dL SGPT no greater than 1.5 times upper limit of normal Renal: Creatinine no greater than 1.5 mg/dL Cardiovascular: No unstable angina No clinical evidence of congestive heart failure Pulmonary: No postobstructive pneumonia Other: Fertile patients must use effective contraception Not pregnant or nursing No serious concurrent infection No prior malignancies except basal cell or squamous cell skin carcinomas, stage I colon, cervical, breast, prostate, head and neck, or lung cancer, as long as there has been no evidence of tumor occurrence within the past 5 years