PATIENT CHARACTERISTICS: Age: 18 and over Performance status: ECOG 0-2 Life expectancy: Not specified Hematopoietic: Granulocyte count at least 1,500/mm3 Platelet count at least 100,000/mm3 Hepatic: Bilirubin less than 1.5 mg/dL SGOT less than 2 times upper limit of normal (ULN) Renal: Creatinine no greater than ULN Other: Not pregnant or nursing Fertile patients must use effective contraception No concurrent active second malignancy except nonmelanoma skin cancer (i.e., completed therapy and considered to be at less than 30% risk of relapse)