PATIENT CHARACTERISTICS: Age: Not specified Performance status: ECOG 0-3 Life expectancy: Not specified Hematopoietic: WBC at least 3,000/mm3 Platelet count at least 100,000/mm3 Hepatic: Bilirubin no greater than 2.5 times upper limit of normal (ULN) Renal: Creatinine no greater than 2.5 times ULN Other: Not pregnant or nursing Negative pregnancy test Fertile patients must use effective contraception during and for at least 4 months following study No active serious infections that are not controlled by antibiotics