Geographical Distribution and Cluster Detection of Childhood Leukemia in the Metropolitan Area of Guadalajara, Mexico

Alberto Tlacuilo-Parra, UMAE Hospital de Pediatría, Centro Médico Nacional de Occidente, Instituto Mexicano del Seguro Social, Guadalajara, Jal., Mexico
Roberto Garibaldi-Covarrubias, Pediatric Hematology and Oncology Department, UMAE Hospital de Pediatría CMNO, Instituto Mexicano del Seguro Social (IMSS), Guadalajara, Jal. Mexico
Hugo Romo-Rubio, Pediatric Hematology and Oncology Department, UMAE Hospital de Pediatría CMNO, Instituto Mexicano del Seguro Social (IMSS); 3Pediatric Hematology and Oncology Department, Nuevo Hospital Civil de Guadalajara, Jal. Mexico
Leonardo Soto-Sumuano, Medical Research Division, UMAE Hospital de Pediatría CMNO, Instituto Mexicano del Seguro Social (IMSS), Information Systems Department CUCEA, Universidad de Guadalajara, Zapopan, Jal. Mexico
Carlos Fernando Ruiz-Chávez, Information Technology Consultant, Geospatial Data Specialist, Guadalajara, Jal. Mexico
Mijail Suárez-Arredondo, Medical Research Division, UMAE Hospital de Pediatría CMNO, Instituto Mexicano del Seguro Social (IMSS), Guadalajara, Jal. Mexico
Fernando Sánchez-Zubieta, Pediatric Hematology and Oncology Department, Nuevo Hospital Civil de Guadalajara, Guadalajara, Jal. Mexico
Sergio Gallegos-Castorena, Pediatric Hematology and Oncology Department, Nuevo Hospital Civil de Guadalajara, Guadalajara, Jal. Mexico

Background: Acute leukemia is the most common cancer in childhood. Analyzing the spatial distribution of acute leukemia may generate the identification of risk factors. Objective: To study the incidence rate of acute leukemia, its geographic distribution, and cluster detection in the metropolitan area of Guadalajara, Mexico. Methods: We included children under 15 years of age diagnosed with acute leukemia during the period 2010-2014 in the metropolitan area of Guadalajara. Each case was geo-referenced to street level to latitude and longitude coordinates using Quantum Geographic Information System (QGIS). Spatial clusters were found in the location of the acute leukemia cases applying the Density-Based Spatial Clustering of Applications with Noise (DBSCAN) algorithm with R statistical software. Results: A total of 269 cases of leukemia were registered, 227 (84%) were acute lymphoblastic leukemia and 42 (16%) acute myeloblastic leukemia. The mean age was 6 ± 4 years. The mean incidence of acute leukemia was 6.44 cases/100,000 inhabitants: El Salto 10.12/100,000, Guadalajara 7.55/100,000, and Tlaquepaque 6.74/100,000. The DBSCAN found three clusters, all located within the municipality of Guadalajara. Conclusions: The incidence of acute leukemia in our population is higher than that in Canada and the USA. We found three spatial clusters of childhood acute lymphoblastic leukemia in the municipality of Guadalajara, suggesting the presence of local predisposing factors.

Keywords: Cancer. Childhood. Density based clustering. Disease mapping. Geographic information system. Leukemia. Spatial epidemiology.