title: Tobacco smoking and esophageal and gastric cardia adenocarcinoma: a meta-analysis.
abstract: BACKGROUND
  Smoking has been related to esophageal and gastric cardia adenocarcinoma, but the magnitude of the association is uncertain.
  
  
  METHODS
  We conducted a meta-analysis of 33 studies published up to January 2010. We derived summary estimates using random-effects models.
  
  
  RESULTS
  Compared with never-smokers, the pooled relative risk (RR) was 1.76 (95% confidence interval = 1.54-2.01) for ever-smokers, 2.32 (1.96-2.75) for current smokers, and 1.62 (1.40-1.87) for ex-smokers. There was no important difference between esophageal (RR = 1.85 for ever- vs. never-smokers) and gastric cardia (RR = 1.76) adenocarcinoma. We found a direct association with dose (RR = 2.48 [2.14-2.86] for ≥ 20 cigarettes/d) and duration (RR = 2.32 [1.92-2.82] for ≥ 40 years) of cigarette consumption.
  
  
  CONCLUSIONS
  This meta-analysis estimates the excess of esophageal and gastric cardia adenocarcinoma risk for smokers. This risk was similar for the 2 cancer sites.
authors.affiliation: Istituto di Ricerche Farmacologiche Mario Negri, Milano, Italy.
authors.forename: Irene
authors.initials: I
authors.lastname: Tramacere
authors.forename: Carlo
authors.initials: C
authors.lastname: La Vecchia
authors.forename: Eva
authors.initials: E
authors.lastname: Negri
mesh_terms: D000230:Adenocarcinoma / Q000453:epidemiology* / Q000473:pathology / Q000628:therapy; D000328:Adult; D000368:Aged; D002299:Cardia / Q000473:pathology*; D016022:Case-Control Studies; D015331:Cohort Studies; D015897:Comorbidity; D004938:Esophageal Neoplasms / Q000453:epidemiology* / Q000473:pathology / Q000628:therapy; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D018570:Risk Assessment; D012907:Smoking / Q000009:adverse effects / Q000453:epidemiology*; D013274:Stomach Neoplasms / Q000453:epidemiology* / Q000473:pathology / Q000628:therapy; D016019:Survival Analysis