PATIENT CHARACTERISTICS: Age: 18 and over Performance status: Karnofsky 60-100% Life expectancy: At least 12 weeks Hematopoietic: See Disease Characteristics Hepatic: See Disease Characteristics Bilirubin no greater than 2 times upper limit of normal No liver dysfunction due to organ infiltration by lymphocytes Renal: Creatinine clearance at least 50 mL/min Other: Not pregnant or nursing Negative pregnancy test Fertile patients must use effective contraception during and for up to 28 days after study No neurotoxicity of grade 2 or higher No history of significant neurologic toxicity (grade 2 or greater motor or sensory impairment) due to prior chemotherapy or radiotherapy No history of seizure disorder No active infection No other malignancy within the past 2 years (except adequately treated non- melanomatous skin cancer or carcinoma in situ) that would preclude study No systemic nonmalignant comorbid disease that would preclude study No psychological, sociological, or geographical condition that would preclude study