title: Relationship between Helicobacter pylori infection and esophageal neoplasia: a meta-analysis.
abstract: OBJECTIVE
  Helicobacter pylori is an important causative factor in gastric carcinogenesis. However, its role in extragastric gastrointestinal malignancies, such as esophageal cancer, is controversial. The aim of this study was to explore the relationship of H. pylori infection and H. pylori cagA-positive strain with this malignancy by performing meta-analysis of all relevant studies.
  
  
  METHODS
  Extensive MEDLINE English language medical literature searches for human studies were performed through February 2007 with suitable keywords. Pooled estimates were obtained by using fixed or random-effects model as appropriate. Heterogeneity between studies was evaluated with the Cochran Q test, whereas the likelihood of publication bias was assessed by constructing funnel plots. Their symmetry was estimated by the Begg and Mazumdar adjusted rank correlation test.
  
  
  RESULTS
  In adenocarcinoma patients there were inverse significant relationships with both the H. pylori prevalence (pooled odds ratio [OR], 0.52; 95% confidence interval [CI], 0.37-0.73; P < .001) and the prevalence of H. pylori cagA-positive strain (pooled OR, 0.51; 95% CI, 0.31-0.82; P = .006). Similarly in patients with Barrett's esophagus there were inverse significant relationships (pooled OR, 0.64; 95% CI, 0.43-0.94; P = .025 and pooled OR, 0.39; 95% CI, 0.21-0.76; P = .005, respectively). In patients with squamous cell carcinoma there were no significant relationships with both H. pylori prevalence (pooled OR, 0.85; 95% CI, 0.55-1.33; P = .48) and the prevalence of H. pylori cagA-positive strains (pooled OR, 1.22; 95% CI, 0.7-2.13; P = .48).
  
  
  CONCLUSIONS
  The results showed an inverse statistically significant relationship of H. pylori infection with both esophageal adenocarcinoma and Barrett's esophagus, which might suggest a protective role of the infection in these entities. On the contrary, no statistically significant relationship with squamous cell carcinoma was found.
authors.affiliation: Gastroenterology Clinic, Henry Dunant Hospital, Athens, Greece.
authors.forename: Theodoros
authors.initials: T
authors.lastname: Rokkas
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Pistiolas
authors.forename: Panos
authors.initials: P
authors.lastname: Sechopoulos
authors.forename: Ioannis
authors.initials: I
authors.lastname: Robotis
authors.forename: Georgios
authors.initials: G
authors.lastname: Margantinis
mesh_terms: D000230:Adenocarcinoma / Q000453:epidemiology / Q000209:etiology* / Q000473:pathology; D016001:Confidence Intervals; D004938:Esophageal Neoplasms / Q000453:epidemiology / Q000209:etiology* / Q000473:pathology; D014943:Global Health; D016481:Helicobacter Infections / Q000150:complications* / Q000453:epidemiology / Q000382:microbiology; D016480:Helicobacter pylori / Q000302:isolation & purification*; D006801:Humans; D016017:Odds Ratio; D015995:Prevalence; D012307:Risk Factors