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.
From the aIstituto di Ricerche Farmacologiche “Mario Negri,” Milano, Italy; and bSection of Medical Statistics, Department of Occupational Health, Università degli Studi di Milano, Milan, Italy.
Submitted 25 June 2010; accepted 22 October 2010; posted 17 February 2011.
Supported by The Italian Association for Cancer Research (AIRC); and a fellowship from the Italian Foundation for Cancer Research (FIRC) (to I.T.).
Correspondence: Eva Negri, Istituto di Ricerche Farmacologiche “Mario Negri,” Via Giuseppe La Masa 19, 20156 Milan, Italy. E-mail: firstname.lastname@example.org.