Clinical course and prognostic factors of children with Burkitt's lymphoma in a developing country: the experience of a single centre in Brazil

OBJECTIVE: Burkitt's lymphoma is the most common subtype of non-Hodgkin lymphoma in children. The aim of this study was to characterize the clinical course and prognostic factors of children and adolescents with Burkitt's lymphoma treated in the Hematology Unit of Hospital das Clínicas, Universidade Federal de Minas Gerais (UFMG). METHODS: A retrospective cohort study was made of 50 consecutive cases of children and adolescents aged 16 years or less with Burkitt's lymphoma admitted between January 1981 and December 2007. Prognostic factors associated with death were evaluated using the Kaplan-Meier method and compared by the two-tailed log-rank test. RESULTS: The median age at diagnosis was 4.7 years. Most patients had abdominal tumors (66.7%) and advanced disease (68.9%) at diagnosis. Thirty-eight patients (84.4%) achieved complete clinical remission and 33 (73.3%) were alive at the first remission. Twelve children (26.7%) died. The median follow-up was 35 months with the probability of overall survival being 73% (89.2% and 35.7% for patients with uric acid < 7 mg/dL and ≥ 7.0 mg/dL, respectively - p-value < 0.001). Uric acid was the only significant prognostic factor at diagnosis. CONCLUSION: Our findings confirm the favorable prognosis of children with Burkitt's lymphoma even when treated with intermediate doses of methotrexate (500 mg/m2). Survival was significantly lower for individuals with concentrations of uric acid > 7 mg/dL.