title: Infection with Helicobacter pylori strains possessing cagA is associated with an increased risk of developing adenocarcinoma of the stomach.
abstract: To determine whether infection with a Helicobacter pylori strain possessing cagA is associated with an increased risk of development of adenocarcinoma of the stomach, we used a nested case-control study based on a cohort of 5443 Japanese-American men in Oahu, Hawaii, who had a physical examination and a phlebotomy during 1967 to 1970. We matched 103 H. pylori-infected men who developed gastric cancer during a 21-year surveillence period with 103 H. pylori-infected men who did not develop gastric cancer and tested stored serum specimens from patients and controls for the presence of serum IgG to the cagA product of H. pylori using an ELISA. The serum IgG assay using a recombinant CagA fragment had a sensitivity of 94.4% and a specificity of 92.5% when used in a clinically defined population; serological results were stable for more than 7 years. For men with antibodies to CagA, the odds ratio of developing gastric cancer was 1.9 (95% confidence interval, 0.9-4.0); for intestinal type cancer of the distal stomach, the odds ratio was 2.3 (95% confidence interval, 1.0-5.2). Age < 72 years and advanced tumor stage at diagnosis were significantly associated with CagA seropositivity. We conclude that infection with a cagA-positive H. pylori strain in comparison with a cagA-negative strain somewhat increases the risk for development of gastric cancer, especially intestinal type affecting the distal stomach.
authors.affiliation: Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, USA.
authors.forename: M J
authors.initials: MJ
authors.lastname: Blaser
authors.forename: G I
authors.initials: GI
authors.lastname: Perez-Perez
authors.forename: H
authors.initials: H
authors.lastname: Kleanthous
authors.forename: T L
authors.initials: TL
authors.lastname: Cover
authors.forename: R M
authors.initials: RM
authors.lastname: Peek
authors.forename: P H
authors.initials: PH
authors.lastname: Chyou
authors.forename: G N
authors.initials: GN
authors.lastname: Stemmermann
authors.forename: A
authors.initials: A
authors.lastname: Nomura
mesh_terms: D000230:Adenocarcinoma / Q000382:microbiology*; D016022:Case-Control Studies; D005798:Genes, Bacterial / Q000235:genetics* / Q000276:immunology; D016481:Helicobacter Infections / Q000150:complications / Q000382:microbiology*; D016480:Helicobacter pylori / Q000235:genetics*; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood*; D008297:Male; D016017:Odds Ratio; D013274:Stomach Neoplasms / Q000382:microbiology*
chemical_list: D007074:Immunoglobulin G