PATIENT CHARACTERISTICS: Age: 18 and over Performance status: Karnofsky 60-100% Hematopoietic: Absolute neutrophil count at least 500/mm3 Platelet count greater than 25,000/mm3 (unless secondary to lymphoma) Hepatic: Transaminases less than 5 times upper limit of normal AND Bilirubin less than 2.0, unless secondary to lymphoma Renal: Creatinine less than 2.0 mg/dL OR Creatinine clearance at least 60 mL/min Dose reduction of 21% if creatinine clearance 10-50 mL/min Dose reduction of 50% if creatinine clearance less than 10 mL/min Cardiovascular: No active cardiac arrhythmia or angina Pulmonary: Must exclude Pneumocystis carinii pneumonia if there is any suspicion of infection Other: No uncontrolled infections Not pregnant or nursing Adequate contraception for fertile patients