PATIENT CHARACTERISTICS: Age: 18 and over Performance status: Zubrod 0-2 Life expectancy: At least 12 weeks Hematopoietic: Absolute neutrophil count (ANC) at least 1,000/mm3 (at least 500/mm3 if extensive bone marrow involvement) Platelets at least 75,000/mm3 (at least 50,000/mm3 if extensive bone marrow involvement) Hepatic: Bilirubin less than 1.5 mg/dL ALT and AST less than 2.5 times upper limit of normal Renal: Creatinine no greater than 1.5 mg/dL OR Creatinine clearance at least 60 mL/min Other: Not pregnant or nursing Fertile patients must use effective contraception during and for 2 months after study