Esperanza Trujillo1, Teresa Martínez2, María Mercedes Bravo1. 1. Grupo de Investigación en Cáncer y Agentes Infecciosos, Instituto Nacional de Cancerología, Bogotá, D.C, Colombia. 2. Grupo de Investigación Epidemiológica del Cáncer, Instituto Nacional de Cancerología, Bogotá, D.C, Colombia.
Abstract
INTRODUCTION: The overall prevalence of Helicobacter pylori infection is high in Colombia; however, in the country´s Andean region, gastric cancer rates far surpass those in coastal areas. Helicobacter pylori genotypes cagA positive and vacA s1 and m1 are associated with an increased risk of gastric cancer. OBJECTIVE: To compare the distribution of H. pylori genotypes associated with virulence in two regions in Colombia with opposing risk for gastric cancer. MATERIALS AND METHODS: Four hundred and one gastric antral biopsies were obtained and analyzed from 401 individuals diagnosed with non-atrophic gastritis, atrophic gastritis and intestinal metaplasia: 256 came from the high-risk area cities of Tunja and Bogotá, and 145 from the low-risk area cities of Barranquilla, Santa Marta and Cartagena. Genotyping of virulence genes vacA and cagA was performed by PCR. RESULTS: No difference was observed in the frequency of H. pylori infection between the two areas (77.3% vs 77.9 %, p=non significant, ns). The presence of cagA was higher in the low-risk area (77.9% vs. 69.2 %, p=ns). The vacA s1 allele was also more prevalent in the low-risk area (61.8 % vs 72.0 %, p=ns). The vacA m1 allele was more prevalent in the high-risk area (57.2 % vs 42.8 %, p=ns). The cagA positive s1m1 combination was also more frequent in the low-risk area (48.9% vs 38.9%, p=ns). CONCLUSIONS: The differences in the risk of gastric cancer in these two geographic areas cannot be explained by differences in the prevalence of infection by H. pylori or by differences in the virulence of circulating strains.
INTRODUCTION: The overall prevalence of Helicobacter pyloriinfection is high in Colombia; however, in the country´s Andean region, gastric cancer rates far surpass those in coastal areas. Helicobacter pylori genotypes cagA positive and vacA s1 and m1 are associated with an increased risk of gastric cancer. OBJECTIVE: To compare the distribution of H. pylori genotypes associated with virulence in two regions in Colombia with opposing risk for gastric cancer. MATERIALS AND METHODS: Four hundred and one gastric antral biopsies were obtained and analyzed from 401 individuals diagnosed with non-atrophic gastritis, atrophic gastritis and intestinal metaplasia: 256 came from the high-risk area cities of Tunja and Bogotá, and 145 from the low-risk area cities of Barranquilla, Santa Marta and Cartagena. Genotyping of virulence genes vacA and cagA was performed by PCR. RESULTS: No difference was observed in the frequency of H. pyloriinfection between the two areas (77.3% vs 77.9 %, p=non significant, ns). The presence of cagA was higher in the low-risk area (77.9% vs. 69.2 %, p=ns). The vacA s1 allele was also more prevalent in the low-risk area (61.8 % vs 72.0 %, p=ns). The vacA m1 allele was more prevalent in the high-risk area (57.2 % vs 42.8 %, p=ns). The cagA positive s1m1 combination was also more frequent in the low-risk area (48.9% vs 38.9%, p=ns). CONCLUSIONS: The differences in the risk of gastric cancer in these two geographic areas cannot be explained by differences in the prevalence of infection by H. pylori or by differences in the virulence of circulating strains.
Authors: Yeison Carlosama-Rosero; Claudia Acosta-Astaiza; Carlos H Sierra-Torres; H Bolaños-Bravo; Andrés Quiroga-Quiroga; Juan Bonilla-Chaves Journal: Can J Gastroenterol Hepatol Date: 2022-09-28