PATIENT CHARACTERISTICS: Age: Over 16 Performance status: Zubrod 0-2 Life expectancy: Greater than 8 weeks Hematopoietic: Absolute neutrophil count at least 1,000/mm3 Platelet count at least 100,000/mm3 Hepatic: Bilirubin no greater than 1.5 times upper limit of normal (ULN) Transaminase no greater than 3 times ULN Renal: Creatinine no greater than 2.0 mg/dL Other: Not pregnant or nursing Negative pregnancy test Fertile patients must use effective contraception during and for 1 year after study No serious concurrent illness