PATIENT CHARACTERISTICS: Age: 18 and over Performance status: Karnofsky 60-100% Life expectancy: Not specified Hematopoietic: Absolute neutrophil count at least 1,500/mm3 OR WBC at least 3,500/mm3 AND Platelet count at least 100,000/mm3 Hepatic: Bilirubin no greater than 1.5 mg/dL No known Gilbert's syndrome No other significant hepatic disease requiring medication Renal: Creatinine no greater than 1.5 mg/dL Cardiovascular: No significant cardiac disease requiring medication Other: Not pregnant or nursing Fertile patients must use effective contraception No other significant medical condition