PATIENT CHARACTERISTICS: Age: 18 and over Performance status: ECOG 0-2 Life expectancy: At least 3 months Hematopoietic: Neutrophil count at least 1,500/mm3 Platelet count at least 100,000/mm3 Hepatic: Bilirubin no greater than 2.0 mg/dL AST no greater than 2 times upper limit of normal Renal: Creatinine no greater than 2.0 mg/dL Other: Not pregnant or nursing Negative pregnancy test Fertile patients must use effective contraception