title: Hiatal hernia, reflux symptoms, body size, and risk of esophageal and gastric adenocarcinoma.
abstract: BACKGROUND
  Since the 1970s, incidence rates of esophageal and gastric cardia adenocarcinoma have risen substantially. Reasons for the increasing trends are not well understood.
  
  
  METHODS
  A population-based, case-control study that included esophageal adenocarcinomas (n = 222), gastric cardia adenocarcinomas (n = 277), distal gastric adenocarcinomas (n = 443), and 1356 controls was conducted in Los Angeles County. Unconditional logistic regression was used to calculate odds ratios (ORs) and corresponding 95% confidence intervals (CIs) for the 3 tumor types.
  
  
  RESULTS
  After adjustment for demographic factors, smoking, and body size, both hiatal hernia and reflux symptoms emerged as significant independent risk factors. Risk of esophageal adenocarcinoma was increased 3-fold (adjusted OR, 3.61; 95% CI, 2.49-5.25) among those who had reflux symptoms but did not have hiatal hernia, 6-fold (adjusted OR, 5.85; 95% CI, 3.18-10.75) among those who had hiatal hernia but did not have reflux symptoms, and 8-fold (adjusted OR, 8.11; 95% CI, 4.75-13.87) among those who had both reflux symptoms and hiatal hernia. A similar risk pattern was found in relation to history of hiatal hernia and other reflux conditions. A more modest but still significant risk pattern was observed for gastric cardia adenocarcinoma. Among control subjects, there was a significant and positive association between increasing body mass index and history of hiatal hernia and/or reflux symptoms.
  
  
  CONCLUSIONS
  Hiatal hernia, in combination with other reflux conditions and symptoms, was associated strongly with the risk of esophageal adenocarcinoma. These associations were more modest for gastric cardia adenocarcinomas. A significant and positive association between body size and history of hiatal hernia/reflux symptoms also was observed.
authors.affiliation: Department of Preventive Medicine, Keck School of Medicine, University of Southern California/Norris Comprehensive Cancer Center, 1441 Eastlake Avenue, MC 9175, Los Angeles, CA 90089-9175, USA. annawu@hsc.usc.edu
authors.forename: Anna H
authors.initials: AH
authors.lastname: Wu
authors.forename: Chiu-Chen
authors.initials: CC
authors.lastname: Tseng
authors.forename: Leslie
authors.initials: L
authors.lastname: Bernstein
mesh_terms: D000230:Adenocarcinoma / Q000453:epidemiology / Q000209:etiology*; D000328:Adult; D000368:Aged; D001824:Body Constitution; D016022:Case-Control Studies; D004938:Esophageal Neoplasms / Q000453:epidemiology / Q000209:etiology*; D005260:Female; D005764:Gastroesophageal Reflux / Q000150:complications*; D006551:Hernia, Hiatal / Q000150:complications*; D006801:Humans; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D012044:Regression Analysis; D012307:Risk Factors; D013274:Stomach Neoplasms / Q000453:epidemiology / Q000209:etiology*