Alcohol consumption and the risks of adenocarcinoma and squamous cell carcinoma of the esophagus.

BACKGROUND AND AIMS: Alcohol has been declared a carcinogen for cancers of the esophagus, although the evidence relates largely to the squamous subtype. Evidence for an effect on adenocarcinomas is scant and inconsistent.
METHODS: We compared nationwide samples of patients with esophageal adenocarcinoma (EAC) (n=365) or esophagogastric junction adenocarcinoma (EGJAC) (n=426) or esophageal squamous cell carcinoma (ESCC) (n=303) with controls sampled from a population register (n=1580). We used generalized additive models to assess nonlinear effects of self-reported alcohol intake on cancer risk, and calculated odds ratios (ORs) and 95% confidence intervals (CIs) using multivariate logistic and piecewise regression.
RESULTS: We observed no association between average weekly alcohol intake and EAC or EGJAC risk. For ESCC, the relationship with alcohol was nonlinear. At intakes of less than 170 g/wk there was no significant association; at greater than this level, there was a significant linear effect (OR, 1.03; 95% CI, 1.02-1.05 per 10 g alcohol/wk). For ESCC, but not EAC or EGJAC, a statistically significant multiplicative interaction between smoking and alcohol was observed (P=.02). In analyses by beverage type, ESCC risks, but not EAC or EGJAC, increased linearly with beer intake (OR, 1.05; 95% CI, 1.04-1.07). Those who drank modest levels of wine (<50-90 g/wk) or port or spirits (<10-20 g/wk) had significantly lower risks of all 3 cancers than nondrinkers; higher intakes were associated with increased risks of ESCC only.
CONCLUSIONS: Alcohol intake above the recommended US dietary guidelines significantly increases the risk of ESCC, but not EAC or EGJAC. Smoking modifies the effect of alcohol intake on ESCC risk.