PATIENT CHARACTERISTICS: Age: 18 and over Performance status: SWOG 0-2 Karnofsky 70-100% Life expectancy: At least 12 weeks Hematopoietic: Absolute neutrophil count at least 1,500/mm3 Platelet count at least 100,000/mm3 Hemoglobin greater than 9 g/dL Hepatic: Bilirubin less than 1.5 times upper limit of normal (ULN) AST and ALT less than 3 times ULN Renal: Creatinine no greater than 1.5 mg/dL OR Creatinine clearance at least 60 mL/min Calcium no greater than 12 mg/dL Cardiovascular: No myocardial infarction within 6 months No congestive heart failure requiring therapy No unstable angina Other: Not pregnant or nursing Negative pregnancy test Fertile patients must use effective contraception No active infection No other concurrent severe disease No psychiatric disorders No history of seizure disorders No uncontrolled diabetes (blood sugar no greater than 200 mg/dL)