title: Helicobacter pylori infection: a protective factor for esophageal squamous cell carcinoma in a Taiwanese population.
abstract: OBJECTIVE
  Many researchers have reported the inverse relationship between Helicobacter pylori (H. pylori) infection and esophageal adenocarcinoma risk, but very few studies have examined the association between H. pylori infection and the development of esophageal squamous-cell carcinoma (ESCC). Therefore, the aim of this study is to evaluate the relationship between H. pylori infection and ESCC risk.
  
  
  METHODS
  Subjects were cancer cases, pathologically proven to have ESCC, in two large medical centers in Kaohsiung metropolitan of southern Taiwan between August 2000 and May 2003. Controls were from the healthy subjects who lived in Kaohsiung metropolitan and voluntarily participated in one large multiyear of gene-environmental study. In total, 127 cases (116 males and 11 females) and 171 controls (161 males and 10 females) were recruited in the same period of time for interviews. H. pylori seropositivity was determined by an enzyme-linked immunosorbant assay measuring IgG.
  
  
  RESULTS
  A total of 28 (22.1%) and 74 (43.3%) out of 127 cases and 171 controls, respectively, had positive H. pylori infection. After adjusting for other covariates, subjects with positive H. pylori infections had a significantly reduced risk (adjusted odds ratio (AOR) = 0.51; 95% CI = 0.27-0.96; p= 0.037) of developing ESCC than those without. This result was even more pronounced in the groups of younger subjects, nonsmokers, or nondrinkers. In addition, among the 117 cancer patients who provided information about site of cancer lesion, the present study found that subjects with cancer lesions in the lower third of the esophagus had significantly fewer positive H. pylori infections (AOR = 0.34; 95% CI = 0.14-0.80; p= 0.013) than controls.
  
  
  CONCLUSIONS
  Our findings suggest that H. pylori infection may protect against the development of ESCC. Additional studies are needed to confirm these findings.
authors.affiliation: Department of Gastroentology, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan.
authors.forename: Deng-Chyang
authors.initials: DC
authors.lastname: Wu
authors.forename: I-Chen
authors.initials: IC
authors.lastname: Wu
authors.forename: Jang-Ming
authors.initials: JM
authors.lastname: Lee
authors.forename: Hon-Ki
authors.initials: HK
authors.lastname: Hsu
authors.forename: Ein-Long
authors.initials: EL
authors.lastname: Kao
authors.forename: Shah-Hwa
authors.initials: SH
authors.lastname: Chou
authors.forename: Ming-Tsang
authors.initials: MT
authors.lastname: Wu
mesh_terms: D002294:Carcinoma, Squamous Cell / Q000453:epidemiology; D004938:Esophageal Neoplasms / Q000453:epidemiology; D005260:Female; D016481:Helicobacter Infections / Q000453:epidemiology; D016480:Helicobacter pylori; D006801:Humans; D008297:Male; D013624:Taiwan / Q000453:epidemiology