title: Serological response to Helicobacter pylori infection among Latin American populations with contrasting risks of gastric cancer.
abstract: Gastric cancer is a rare outcome of chronic Helicobacter pylori infection. Serologic profiles may reveal bacterial, environmental and/or host factors associated with cancer risk. We therefore compared specific anti-H. pylori antibodies among populations with at least twofold differences in gastric cancer mortality from Mexico, Colombia and Chile. Our study included 1,776 adults (mean age 42 years) from three nationally representative surveys, equally divided between residents of high- and low-risk areas. Antibodies to 15 immunogenic H. pylori antigens were measured by fluorescent bead-based multiplex assays; results were summarized to identify overall H. pylori seropositivity. We used logistic regression to model associations between antibody seroreactivity and regional cancer risk (high vs. low), adjusting for country, age and sex. Both risk areas had similar H. pylori seroprevalence. Residents in high- and low-risk areas were seroreactive to a similar number of antigens (means 8.2 vs. 7.9, respectively; adjusted odds ratio, OR: 1.02, p = 0.05). Seroreactivities to Catalase and the known virulence proteins CagA and VacA were each significantly (p < 0.05) associated with residence in high-risk areas, but ORs were moderate (1.26, 1.42 and 1.41, respectively) and their discriminatory power was low (area under the curve < 0.6). The association of Catalase was independent from effects of either CagA or VacA. Sensitivity analyses for antibody associations restricted to H. pylori-seropositive individuals generally replicated significant associations. Our findings suggest that humoral responses to H. pylori are insufficient to distinguish high and low gastric cancer risk in Latin America. Factors determining population variation of gastric cancer burden remain to be identified.
authors.affiliation: Division of Cancer Epidemiology and Genetics, National Cancer Institute, Rockville, MD.
authors.forename: M Constanza
authors.initials: MC
authors.lastname: Camargo
authors.affiliation: Dirección de Redes en Salud Pública, Instituto Nacional de Salud, Bogotá, Colombia.
authors.forename: Mauricio
authors.initials: M
authors.lastname: Beltran
authors.affiliation: Centro de Investigación en Salud Poblacional, Instituto Nacional de Salud Pública, Cuernavaca, Morelos, México.
authors.forename: Carlos J
authors.initials: CJ
authors.lastname: Conde-Glez
authors.affiliation: Departamento de Gastroenterología y Nutrición Pediátrica, Pontificia Universidad Católica de Chile, Santiago, Chile.
authors.forename: Paul R
authors.initials: PR
authors.lastname: Harris
authors.affiliation: Division of Genome Modifications and Carcinogenesis, Infection and Cancer Program, German Cancer Research Center (DFKZ), Heidelberg, Germany.
authors.forename: Angelika
authors.initials: A
authors.lastname: Michel
authors.affiliation: Division of Genome Modifications and Carcinogenesis, Infection and Cancer Program, German Cancer Research Center (DFKZ), Heidelberg, Germany.
authors.forename: Tim
authors.initials: T
authors.lastname: Waterboer
authors.affiliation: Laboratorio de Parasitología, Dirección de Redes en Salud Pública, Laboratorio Nacional de Referencia, Instituto Nacional de Salud, Bogotá, Colombia.
authors.forename: Astrid
authors.initials: A
authors.lastname: Carolina Flórez
authors.affiliation: Unidad de Investigación en Enfermedades Infecciosas, UMAE Pediatría, CMN SXXI, Instituto Mexicano del Seguro Social, México City, México.
authors.forename: Javier
authors.initials: J
authors.lastname: Torres
authors.affiliation: Crónicas Advanced Center for Chronic Diseases, Departamento de Salud Pública, Pontificia Universidad Católica de Chile, Santiago, Chile.
authors.forename: Catterina
authors.initials: C
authors.lastname: Ferreccio
authors.affiliation: Division of Cancer Epidemiology and Genetics, National Cancer Institute, Rockville, MD.
authors.forename: Joshua N
authors.initials: JN
authors.lastname: Sampson
authors.affiliation: Division of Genome Modifications and Carcinogenesis, Infection and Cancer Program, German Cancer Research Center (DFKZ), Heidelberg, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Pawlita
authors.affiliation: Division of Cancer Epidemiology and Genetics, National Cancer Institute, Rockville, MD.
authors.forename: Charles S
authors.initials: CS
authors.lastname: Rabkin
mesh_terms: D000328:Adult; D000907:Antibodies, Bacterial / Q000097:blood*; D005260:Female; D016481:Helicobacter Infections / Q000097:blood* / Q000276:immunology / Q000401:mortality; D016480:Helicobacter pylori / Q000276:immunology*; D006630:Hispanic or Latino; D006801:Humans; D008297:Male; D012306:Risk; D012680:Sensitivity and Specificity; D013274:Stomach Neoplasms / Q000276:immunology / Q000382:microbiology* / Q000401:mortality; D016019:Survival Analysis
chemical_list: D000907:Antibodies, Bacterial
keywords: H. pylori; Latin America; gastric cancer; serology