Heavier Alcohol Consumption Linked to Colorectal Cancer

Researchers conducted a meta-analysis of case-control and cohort studies to assess the dose-response relationship between alcohol consumption and colorectal cancer. Categories of alcohol intake were defined by the authors as follows: light (≤1 standard drink* per day), moderate (>1–<4 drinks per day), and heavy (≥4 drinks per day). Results were adjusted for sex, colorectal cancer site, and study location. Twenty-two studies from Asia, 2 from Australia, 13 from Western Europe, and 24 from North America were included in the analysis. Nondrinkers or occasional drinkers were used as the reference category.

• Higher levels of alcohol consumption were associated with an increased risk of colorectal cancer: although there was no increased risk for light drinking, an increase of 21% was seen for moderate drinking (12.5–49.9 g alcohol per day), and an increase of 52% was seen for heavy drinking (≥50 g per day).

Comments:

According to this well-done study, alcohol intake, especially heavier intake, is associated with an increased risk of colorectal cancer. There are some key concerns, however, in that the upper limit of “moderate” drinking used in this study is well above usual recommended limits for sensible drinking; narrower categories of consumption (e.g., 1–2 or 2–3 drinks per day) were not assessed; and results were not adjusted for beverage type or drinking pattern. Future studies are needed to determine whether a threshold level of alcohol intake exists with relation to colorectal cancer risk and the effect of beverage type and drinking pattern (regular versus heavy episodic drinking) on that risk.

R. Curtis Ellison, MD

Reference:

Fedirko V, Tramacere I, Bagnardi V, et al. Alcohol drinking and colorectal cancer risk: an overall and dose-response meta-analysis of published studies. Ann Oncol. 2011;22(9):1958–1972.