Background: In order to provide a precise quantification of the association between alcohol drinking and esophageal and gastric cardia adenocarcinoma risk, we conducted a meta-analysis of available data.
Patients and methods: We identified 20 case-control and 4 cohort studies, including a total of 5500 cases. We derived meta-analytic estimates using random-effects models, taking into account correlation between estimates, and we carried out a dose-risk analysis using nonlinear random-effects meta-regression models.
Results: The relative risk (RR) for drinkers versus nondrinkers was 0.96 [95% confidence interval (CI) 0.85-1.09] overall, 0.87 (95% CI 0.74-1.01) for esophageal adenocarcinoma and 0.89 (95% CI 0.76-1.03) for gastric cardia adenocarcinoma. Compared with nondrinkers, the pooled RRs were 0.86 for light (≤ 1 drink per day), 0.90 for moderate (1 to < 4 drinks per day), and 1.16 for heavy (≥ 4 drinks per day) alcohol drinking. The dose-risk model found a minimum at 25 g/day, and the curve was < 1 up to 70 g/day.
Conclusions: This meta-analysis provides definite evidence of an absence of association between alcohol drinking and esophageal and gastric cardia adenocarcinoma risk, even at higher doses of consumption.