7
views
0
recommends
+1 Recommend
0 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: found
      Is Open Access

      H. pylori Seropositivity before Age 40 and Subsequent Risk of Stomach Cancer: A Glimpse of the True Relationship?

      research-article

      Read this article at

      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          Stomach carcinogenesis involves mucosal and luminal changes that favor spontaneous disappearance of Helicobacter pylori. Therefore, the association between the infection and cancer risk might typically be underestimated. As acquisition of the infection almost invariably occurs before adulthood, the serostatus at age 16–40 should best reflect the lifetime occurrence of the infection. We therefore conducted a case-control study nested within a historic cohort of about 400,000 individuals who donated sera before age 40 to either of two large Swedish Biobanks between 1968 and 2006, and whose records were linked to complete nationwide registers. For each stomach adenocarcinoma case occurring at least 5 years after serum donation 2 controls were selected matched on age, sex and year of donation and biobank. Serum immunoglobulin G antibodies against H. pylori cell-surface antigens (Hp-CSAs) were measured with an enzyme–linked immunosorbent assay and antibodies against CagA with an immunoblot assay. Conditional logistic regression models were used to estimate odds ratios (ORs) for stomach adenocarcinoma among H. pylori infected relative to uninfected. We confirmed 59 incident cases of stomach adenocarcinoma (41 non-cardia tumors) during follow-up. ORs for non-cardia stomach adenocarcinoma among subjects with Hp-CSA antibodies (regardless of CagA serostatus), antibodies against CagA (regardless of Hp-CSA serostatus), and antibodies to both, relative to those who were seronegative to both, were 17.1 (95% confidence interval [CI] 4.0–72.9), 10.9 (95% CI 3.2–36.9), and 48.5 (95% CI 5.8–407.4), respectively. H. pylori infection is a much stronger risk factor for non-cardia stomach adenocarcinoma than initially realized. However, further studies are needed to answer whether it is a necessary cause, as the possibility of misclassification of H. pylori status could not be ruled out in our study.

          Related collections

          Most cited references22

          • Record: found
          • Abstract: not found
          • Article: not found

          Schistosomes, liver flukes and Helicobacter pylori. IARC Working Group on the Evaluation of Carcinogenic Risks to Humans. Lyon, 7-14 June 1994.

            Bookmark
            • Record: found
            • Abstract: found
            • Article: not found

            Epidemiology of stomach cancer.

            Despite a major decline in incidence and mortality over several decades, stomach cancer is still the fourth most common cancer and the second most common cause of cancer death in the world. There is a 10-fold variation in incidence between populations at the highest and lowest risk. The incidence is particularly high in East Asia, Eastern Europe, and parts of Central and South America, and it is about twice as high among men than among women. Prognosis is generally rather poor, with 5-year relative survival below 30% in most countries. The best established risk factors for stomach cancer are Helicobacter pylori infection, the by far strongest established risk factor for distal stomach cancer, and male sex, a family history of stomach cancer, and smoking. While some factors related to diet and food preservation, such as high intake of salt-preserved foods and dietary nitrite or low intake of fruit and vegetables, are likely to increase the risk of stomach cancer, the quantitative impact of many dietary factors remains uncertain, partly due to limitations of exposure assessment and control for confounding factors. Future epidemiologic research should pay particular attention to differentiation of stomach cancer epidemiology by subsite, and to exploration of potential interactions between H. pylori infection, genetic, and environmental factors.
              Bookmark
              • Record: found
              • Abstract: found
              • Article: not found

              Gastric cancer and Helicobacter pylori: a combined analysis of 12 case control studies nested within prospective cohorts.

              (2001)
              The magnitude of the association between Helicobacter pylori and incidence of gastric cancer is unclear. H pylori infection and the circulating antibody response can be lost with development of cancer; thus retrospective studies are subject to bias resulting from classification of cases as H pylori negative when they were infected in the past. To combine data from all case control studies nested within prospective cohorts to assess more reliably the relative risk of gastric cancer associated with H pylori infection. To investigate variation in relative risk by age, sex, cancer type and subsite, and interval between blood sampling and cancer diagnosis. Studies were eligible if blood samples for H pylori serology were collected before diagnosis of gastric cancer in cases. Identified published studies and two unpublished studies were included. Individual subject data were obtained for each. Matched odds ratios (ORs) and 95% confidence intervals (95% CI) were calculated for the association between H pylori and gastric cancer. Twelve studies with 1228 gastric cancer cases were considered. The association with H pylori was restricted to non-cardia cancers (OR 3.0; 95% CI 2.3-3.8) and was stronger when blood samples for H pylori serology were collected 10+ years before cancer diagnosis (5.9; 3.4-10.3). H pylori infection was not associated with an altered overall risk of cardia cancer (1.0; 0.7-1.4). These results suggest that 5.9 is the best estimate of the relative risk of non-cardia cancer associated with H pylori infection and that H pylori does not increase the risk of cardia cancer. They also support the idea that when H pylori status is assessed close to cancer diagnosis, the magnitude of the non-cardia association may be underestimated.
                Bookmark

                Author and article information

                Contributors
                Role: Editor
                Journal
                PLoS One
                plos
                plosone
                PLoS ONE
                Public Library of Science (San Francisco, USA )
                1932-6203
                2011
                2 March 2011
                : 6
                : 3
                : e17404
                Affiliations
                [1 ]Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
                [2 ]Swedish Institute for Infectious Disease Control, Solna, Sweden
                [3 ]Department of Laboratory Medicine, Karolinska Institutet, Stockholm, Sweden
                Statens Serum Institute, Denmark
                Author notes

                Conceived and designed the experiments: CP ON WY. Performed the experiments: CP YJ HP JD ON WY. Analyzed the data: CP YJ ON WY. Wrote the paper: CP ON WY. Technical or material support: HP JD. Obtained funding: WY.

                [¤a]

                Current address: Hormonal and Reproductive Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, Maryland, United States of America

                [¤b]

                Current address: Department of Basic Medicine, Baotou Medical College, Baotou, China

                Article
                PONE-D-10-04014
                10.1371/journal.pone.0017404
                3047545
                21399687
                f0106059-faf9-4162-8c87-94da712aec07
                This is an open-access article distributed under the terms of the Creative Commons Public Domain declaration which stipulates that, once placed in the public domain, this work may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose.
                History
                : 19 October 2010
                : 2 February 2011
                Page count
                Pages: 5
                Categories
                Research Article
                Medicine
                Clinical Research Design
                Case-Control Studies
                Epidemiology
                Cancer Epidemiology
                Infectious Diseases
                Bacterial Diseases
                Helicobacter Pylori
                Oncology
                Cancer Risk Factors
                Viral and Bacterial Causes of Cancer
                Cancers and Neoplasms
                Gastrointestinal Tumors
                Gastric Cancer

                Uncategorized
                Uncategorized

                Comments

                Comment on this article