The relationship between Helicobacter pylori genes cag E and vir B11 and gastric cancer

Abstract

ackground: The association between Helicobacter pylori gene diversity and gastric cancer has been poorly reported, although it is one of the important ways to explain the gastric pathogenesis. The aim of this study was to investigate the frequency of cag E and vir B11 genes in H. pylori isolated from patients with gastric cancer and to analyze the histology profiles. Materials and methods: The presence of H. pylori and subtypes ( cag E and vir B11) was detected by PCR from the genomic DNA of 101 patients who had been diagnosed with gastric cancer. The cases were grouped according to the presence/absence of the genes studied and were analyzed in relation to histopathological parameters. Results: H. pylori infection was detected in 94 out of 101 (93.1%) gastric carcinomas. The cases were categorized into the following groups: cag E+/ vir B11+, cag E+/ vir B11 , cag E / vir B11+, and cag E / vir B11 . Frequencies were:50% (47/94) cag E+/ vir B11+, 3.2% (3/94) cag E+/ vir B11 , 10.6% (10/94) cag E / vir B11+, and 36.2% (34/94) cag E / vir B11 . Tumors in the gastric antrum were predominant. An exception was the cag E / vir B11 group, in which tumors had a tendency to be located in the gastric cardia; the majority of the cardia tumors (56% (14/25)) were in this group. Intestinal histology type was the most frequent, but the cag E+/ vir B11 group only had diffuse tumors. H. pylori cag E+/ vir B11+ occurred most frequently (except at stage III), and was present at all gastric cancer stages. Conclusions: This study is the first to include a relevant number of gastric cancer cases with H. pylori infection, reporting the frequency and relationship of cag E and vir B11 genes and the genesis of this tumor. The presence of these cag pathogenicity island genes shows that they are important factors for the pathogenesis and malignancy of gastric cancer related to H. pylori