PATIENT CHARACTERISTICS: Age: Over 18 Performance status: Karnofsky 50-100% Life expectancy: At least 2 months Hematopoietic: Granulocyte count greater than 1,500/mm3 Hemoglobin at least 9 g/dL Platelet count greater than 100,000/mm3 Hepatic: SGOT and SGPT no greater than 3 times upper limit of normal (ULN) (no greater than 5 times ULN if tumor involves liver) Bilirubin no greater than 2.0 mg/dL Renal: Creatinine no greater than 2.0 mg/dL Other: Not pregnant or nursing Negative pregnancy test Fertile patients must use effective contraception