Background. Chemotherapy with high dose methotrexate is the mainstay of treatment for Burkitt lymphoma (BL), especially to manage central nervous system (CNS) disease. However, methotrexate administration requires close drug level monitoring for appropriate folinic acid rescue, which might not be readily available in all centers. In this study, we assessed the long-term treatment outcomes of a modified Non-Hodgkin lymphoma (NHL)-Berlin-Frankfurt-Munster (BFM) 90 regimen in pediatric high-risk BL without CNS involvement.

Methods. Between 1999 and 2011, 42 patients (median age: 7 years) with advanced-stage BL were treated with modified NHL-BFM 90 regimen (methotrexate at a dose of 1 g/m2). Demographic data, stage, lactate dehydrogenase (LDH) and treatment results were retrospectively evaluated. The patients were assessed for toxicity, survival and CNS recurrence.

Results. Thirty-six patients had Stage III and six had Stage IV disease, respectively. The median LDH level was 1,432 IU/L. Four patients died of infectious and metabolic complications. One patient had local recurrence at the 48 < sup > th < /sup > month of the follow-up and he is in the second remission for 72 months. In Kaplan-Meier analysis, the overall survival and event-free survival rates at 10 years were found as 90 % and 88 %, respectively. None of our patients died of treatment failure.

Conclusions. The administration of the reduced dose of methotrexate seems to not compromise treatment success nor increase the risk of CNS recurrence in high-risk BL without CNS involvement. The limitation of the study is that it is not randomized. Our treatment scheme might be considered for centers without methotrexate measurement facility.

Keywords: BFM, Burkitt lymphoma, methotrexate