PATIENT CHARACTERISTICS: Age: 18 and over Performance status: ECOG 0-2 Hematopoietic: (within 2 weeks prior to entry) WBC greater than 2,000 Platelets greater than 50,000 Hepatic: Not specified Renal: (within 2 weeks prior to entry) Creatinine less than 2.5 mg/dL OR Creatinine clearance greater than 40 mL/min Other: No pregnant or nursing women Adequate contraception required of fertile patients