PATIENT CHARACTERISTICS: Age: 16 and over Performance status: Not specified Life expectancy: Not specified Hematopoietic: Platelet count at least 50,000/mm3 Absolute neutrophil count at least 750/mm3 Hepatic: SGOT/SGPT less than 3 times upper limit of normal Bilirubin less than 5.0 mg/dL Renal: Not specified Other: No active infection requiring intravenous antibiotics Not HIV positive Not pregnant or nursing Fertile patients must use effective contraception