PATIENT CHARACTERISTICS: Age: 18 and over Performance status: Karnofsky 60-100% Life expectancy: At least 12 weeks Hematopoietic: WBC at least 3,000/mm3 Absolute granulocyte count at least 1,500/mm3 Platelet count at least 100,000/mm3 Hepatic: Bilirubin no greater than 1.8 mg/dL Renal: Creatinine no greater than 1.5 mg/dL OR Creatinine clearance greater than 60 mL/min Other: No medical or psychiatric conditions Not pregnant Adequate contraception required of all fertile patients