Methotrexate, Procarbazine, Lomustine, Dexamethasone, and Cytarabine in Treating Patients With Primary CNS Lymphoma

OBJECTIVES: Primary * Determine the toxicity and efficacy of methotrexate, procarbazine, lomustine, dexamethasone, and cytarabine in patients with primary CNS lymphoma. Secondary * Determine the ability to recruit adequate numbers of patients for this study. * Compare progression-free and dementia-free survival with standard measures of overall survival, progression-free survival, disease-free survival, complete response rate, cognitive function, and quality of life of patients treated with this regimen. * Determine the feasibility of conducting a future phase III study of this treatment regimen in these patients. * Correlate neuropsychological outcomes with neuroimaging (MRI) outcomes in patients treated with this regimen. OUTLINE: This is a nonrandomized, multicenter study. * Induction chemotherapy: Patients receive methotrexate IV over 3 hours on days 1, 10, and 20 and intraventricularly or intrathecally (IT) over 5 minutes on days 1, 5, 10, and 15; oral procarbazine on days 1-7; oral lomustine on day 1; oral dexamethasone every 6 hours on days 1-14 followed by a taper (as tolerated); and cytarabine intraventricularly or IT over 5 minutes on days 1, 5, 10, and 15. Treatment repeats every 42 days for a total of 3 courses. Patients with intraocular lymphoma also receive methotrexate intravitreally twice weekly until the vitreous is clear of cells by slit lamp exam. Patients with stable or responding disease proceed to maintenance therapy. * Maintenance chemotherapy: Patients receive methotrexate IV over 3 hours and IT over 5 minutes on day 1; oral procarbazine on days 1-7; oral lomustine on day 1; oral dexamethasone every 6 hours on days 1-14 followed by a taper (as tolerated); and cytarabine intraventricularly or IT over 5 minutes on day 1. Treatment repeats every 42 days for a total of 5 courses. Patients with intraocular lymphoma also receive methotrexate intravitreally weekly for 1 month and then monthly for 1 year. Quality of life is assessed at baseline, at 6 months, at the completion of treatment, every 6 months for 2 years, and then annually thereafter. Patients are followed every 3 months for 1 year, every 6 months for 2 years, and then annually thereafter. PROJECTED ACCRUAL: A total of 180 patients will be accrued for this study within 3 years.