PATIENT CHARACTERISTICS: Age: 18 and over Performance status: Karnofsky 60-100% Life expectancy: Not specified Hematopoietic: Not specified Hepatic: Bilirubin less than 3 mg/dL SGOT/SGPT no greater than 2.5 times upper limit of normal Renal: Creatinine less than 3 mg/dL Cardiovascular: No overt congestive heart failure or uncontrollable ventricular arrhythmias No uncontrollable hypertension Neurologic: No cerebellar dysfunction Other: Not pregnant or nursing Negative pregnancy test Fertile patients must use effective contraception