Association between alcohol consumption and pancreatic cancer risk: A case-control study

Purpose: Evidence is inconsistent regarding alcohol and pancreatic cancer risk, although heavy drinking may increase risk. Methods: A population-based case-control study was conducted using 345 pancreas cancer cases diagnosed 2011-2012 and 1,285 frequency-matched controls from Ontario, Canada. Logistic regression was used to evaluate alcohol consumption and pancreatic cancer risk; data was also stratified by sex and smoking status to assess interaction. Results: Alcohol consumption was not associated with pancreatic cancer risk (age-adjusted odds ratio=0.78, 95% CI: 0.58, 1.05 for 1-3 drinks/week; age-adjusted odds ratio=0.86, 95% CI: 0.63, 1.17 for 4-20 drinks/week), however there was a non-significant increased risk for heavy drinkers consuming ≥21 drinks/week (age-adjusted odds ratio=1.35, 95% CI: 0.81, 2.27). Cigarette smoking modified the alcohol-cancer relationship; among current smokers, heavy alcohol consumption was associated with a significantly increased pancreatic cancer risk (age-adjusted odds ratio=4.04, 95% CI: 1.58, 10.37), whereas this significant association with heavy drinking was not observed among non-smokers (age-adjusted odds ratio=2.01, 95% CI: 0.50, 8.18). Furthermore, light - moderate alcohol intake was associated with increased pancreas cancer risk among current smokers. Conclusions: While alcohol was not significantly associated with pancreatic cancer risk, smoking status modified this relationship such that among current smokers, alcohol intake was associated with a greater than two-fold increased risk of pancreatic cancer. The results should be interpreted with caution due to small sample sizes within subgroups and correction for multiple comparisons should be considered. These findings should be replicated in larger studies where more precise estimates of risk can be obtained.