title: Gastric atrophy and risk of oesophageal cancer and gastric cardia adenocarcinoma--a systematic review and meta-analysis.
abstract: BACKGROUND
  Several studies have reported an association between gastric atrophy and upper gastrointestinal cancers. Our aim was to summarise the available information and calculate the relative risks (RRs) associated with gastric atrophy for gastric cardia adenocarcinoma (GCA), oesophageal squamous cell carcinoma (OSCC), and oesophageal adenocarcinoma (OAC) by conducting a systematic review and meta-analysis.
  
  
  METHODS
  We searched the PubMed and ISI-Web of Science databases, as well as the reference lists of the relevant articles. Summary RRs and 95% confidence intervals (95% CI) were calculated using random-effects models for the association between gastric atrophy, defined histologically or by serum pepsinogen markers, and OSCC, OAC, and GCA.
  
  
  RESULTS
  Eighteen articles were included in the meta-analysis; 13, 7, and 3 studies reported on GCA, OSCC, and OAC, respectively. The overall RRs (95% CI) for the three cancer types were: GCA, 2.89 (2.09-3.98); OSCC, 1.94 (1.48-2.55); OAC, 0.51 (0.19-1.37). Several subgroup analyses showed the robustness of the results. In the majority of the analyses, there was low to moderate heterogeneity.
  
  
  CONCLUSIONS
  This study found two- to threefold increased risk of OSCC and GCA but a possible reduced risk of OAC in people with gastric atrophy. Further studies are needed to establish the association with OAC and causal association with OSCC, and mechanisms of the increased risk need to be investigated for GCA.
authors.affiliation: Digestive Disease Research Center, Shariati Hospital, Tehran University of Medical sciences, Tehran, Iran; International Agency for Research on Cancer, Lyon, France; King's College London, Thames Cancer Registry, London, UK.
authors.forename: F
authors.initials: F
authors.lastname: Islami
authors.affiliation: Department of Public Health Analysis, School of Community Health and Policy, Morgan State University, Baltimore, USA.
authors.forename: P
authors.initials: P
authors.lastname: Sheikhattari
authors.affiliation: International Agency for Research on Cancer, Lyon, France.
authors.forename: J S
authors.initials: JS
authors.lastname: Ren
authors.affiliation: Department of Public Health Analysis, School of Community Health and Policy, Morgan State University, Baltimore, USA; Digestive Disease Research Center, Shariati Hospital, Tehran University of Medical sciences, Tehran, Iran. Electronic address: farin.kamangar@morgan.edu.
authors.forename: F
authors.initials: F
authors.lastname: Kamangar
mesh_terms: D000230:Adenocarcinoma / Q000209:etiology / Q000473:pathology*; D002294:Carcinoma, Squamous Cell / Q000209:etiology / Q000473:pathology*; D004938:Esophageal Neoplasms / Q000209:etiology / Q000473:pathology*; D005757:Gastritis, Atrophic / Q000150:complications / Q000473:pathology*; D006801:Humans; D012307:Risk Factors; D013274:Stomach Neoplasms / Q000209:etiology / Q000473:pathology*