ABSTRACT
INTRODUCTION: Occasionally, primary care pediatricians notice the presence of small clusters of pediatric cancer (PC), but are often frustrated by the findings after statistical analysis. The study of small areas in spatial epidemiology has led to advances in identifying clusters and the environmental risk factors involved. The purpose of this study was to describe the PC incidence and the spatial distribution at the minimum level of disaggregation possible in Murcia, presenting the first urban municipality map of PC in Spain. MATERIALS AND METHODS: A population-based descriptive study was conducted on the PC cases diagnosed in children younger than 15 years, between 1998 and 2013 in the municipality of Murcia. Cases were classified by sex, age group, and tumor type. Coordinates of home addresses at the time of diagnosis were assigned to each case, and spatial and spatio-temporal analyses were carried out at the level of census tracts, using FleXScan and SatScan. RESULTS: A total of 155 cases of PC were diagnosed during this period. The overall incidence of PC (138/10(6) of children under the age of 15) and the incidence for individual tumor types were within the expected ranges for Europe. A spatio-temporal cluster of Hodgkin lymphoma was identified. CONCLUSIONS: Small area analysis of PC cases may be a useful tool for the identification of PC clusters, which would allow for the generation of hypotheses regarding disease etiology, as well as developing urban models for environmental surveillance of PC.