PATIENT CHARACTERISTICS: Age: 18 and over Performance status: Not specified Life expectancy: At least 12 weeks Hematopoietic: Absolute neutrophil count at least 2,000/mm3 Platelet count at least 100,000/mm3 Hepatic: Bilirubin normal (no greater than 1.5 times upper limit of normal (ULN) if liver metastases present) SGOT and SGPT normal (no greater than 5 times ULN if liver metastases present) Hepatitis B negative Renal: Creatinine less than 1.5 mg/dL EDTA clearance greater than 60 mL/min Other: Not pregnant or nursing Fertile patients must use effective contraception during and for 6 months after study No severe concurrent nonmalignant disease that would preclude protocol therapy HIV negative No AIDS related illness No mental incapacity