Incidence and geographic distribution of endemic Burkitt lymphoma in northern Uganda revisited

Abstract

Endemic Burkitt lymphoma (BL) is etiologically associated with Epstein-Barr virus and ecologically linked to Plasmodium falciparum malaria. However, these infections imperfectly correlate with BL epidemiology. To obtain recent epidemiological data, we studied district- and county-specific BL incidence and standardized incidence ratios using data collected from 1997 to 2006 at Lacor Hospital in northern Uganda, where studies were last done more than 30 years ago. Among 500 patients, median age was 6 years (interquartile range 5-8) and male-to-female ratio was 1.8:1. Among those known, most presented with abdominal (56%, M:F 1.4:1) vs. only facial tumors (35%, M:F 3.0:1). Abdominal tumors occurred in older (mean age: 7.0 vs. 6.0 years; p < 0.001) and more frequently in female children (68% vs. 50%; OR 2.2, 95% CI 1.5-3.5). The age-standardized incidence was 2.4 per 100,000, being 0.6 in 1-4 year olds, 4.1 in 5-9 year olds and 2.8 in 10-14 year olds and varied 3- to 4-fold across districts. The incidence was lower in districts that were far from Lacor and higher in districts that were close to Lacor. Although districts close to Lacor were also more urbanized, the incidence was higher in the nearby perirural areas. We highlight high-BL incidence and geographic variation in neighboring districts in northern Uganda. Although distance from Lacor clearly influenced the patterns, the incidence was lower in municipal than in surrounding rural areas. Jaw tumors were characterized by young age and male gender, but presentation has shifted away from facial to mostly abdominal.