PATIENT CHARACTERISTICS: Age: 18 and over Performance status: ECOG 0-2 Life expectancy: Not specified Hematopoietic: Absolute neutrophil count greater than 1,500/mm3 Platelet count greater than 100,000/mm3 Hepatic: SGOT no greater than 2 times upper limit of normal (ULN) Bilirubin normal Renal: Creatinine no greater than 2 times ULN Other: No unresolved, active bacterial infection requiring antibiotics No other prior malignancy within the past 5 years except adequately treated basal cell or squamous cell skin cancer, carcinoma in situ of the cervix, or adequately treated stage I or II cancer in complete remission Not pregnant or nursing Negative pregnancy test Fertile patients must use effective contraception