Primary Brain Lymphoma: A Retrospective Review of 38 Cases

Background: Primary brain lymphoma (PBL) is an extranodal lymphoma that involves the brain parenchyma and meninges. The incidence of PBL has been increasing at a 2% per year rate in the last decades and it may represent the first among brain tumors in the next 5 years. The prognosis of this disease is poor inspite of aggressive treatment. Material and Methods: Between June 1975 and December 2000, thirty-eight patients with PBL were seen at our center. Thirty-four patients (89%) received external beam radiation therapy (XRT); the dose ranged between 5.4 to 60 Gy with a median of 49 Gy. Treatment volume included the whole brain (WB) with or without boost in 29 patients, and craniospinal axis in 5 cases. One patient received 3 cycles of adjuvant chemotherapy, another patient received intra-thecal methotrexate; and 2 patients received high dose methotrexate prior to irradiation. Our objectives were to study the OS and prognostic variables of these patients and to evaluate their long-term outcome. Results: The mean age at diagnosis was 52.5 years. Eleven patients (29%) were found to have multifocal tumors. Out of 22 evaluable patients, complete response (CR) was achieved in 14 patients (63%) while 6 patients (27%) had partial response (PR). Half of the patients who achieved CR relapsed. Late neurotoxicity was reported in 10 of 16 patients who survived for more than 6 months after therapy. With a median follow up of 24 months, the 3 and 5-year overall survival rates were 30%and 12% respectively. The median survival was 1 year. Age 60 years, performance status 4, solitary brain lesion, XRT dose 40 Gy, WB XRT with boost, and complete response to therapy were found to be associated with statistically significant higher OS rates. Cox regression analysis indicated that performance status, response to therapy, and XRT dose 40 Gy were the most significant prognostic variables. Conclusion: The prognosis of patients with primary brain lymphoma remains poor; with a median survival of only one year. Good performance status ( 4), XRT dose of 40 Gy and complete response to therapy were found to be independent prognostic factors for relatively better outcome. Prospective controlled randomized trials are needed to establish the therapeutic role of chemotherapy as added to WB XRT or even alone.