Two Prospective Cohort Studies Indicate Association between Alcohol Consumption and Cancer

Researchers evaluated the association of alcohol consumption over many years with the risk of cancer based on data from two very large US cohort studies, the Nurses’ Health Study and the Health Professionals Follow-up Study.

• Men reporting an average intake of ≥ 15 g of alcohol in a day had an increased risk of alcohol-related cancers (relative risk [RR], 1.06 (95% CI: 0.98–1.15).
• In non-smoking women, even an average consumption of 5.0–14.9 g of alcohol in a day (the equivalent of ½ – 1 ½ typical drinks) was associated with a slight increase in total cancer risk, primarily from an increase in the risk of breast cancer (RR, 1.04 (CI: 1.00–1.09).
• For both men and women, there seemed to be a linear dose-response increase in risk of cancer.

Comments:

The finding in this study of an increase in some cancers among women even for lighter drinking has implications for alcohol policy. Not included in the analyses were some dietary and other lifestyle factors (e.g., folate levels) that have been shown to relate to the risk of cancer. More importantly, the net effects of light alcohol consumption on mortality were not addressed in the study, which is unfortunate because risks might have been balanced by possible benefits for mortality. Such data could have provided more valuable information upon which to develop appropriate guidelines for alcohol consumption.

R. Curtis Ellison, MD

Reference:

Cao Y, Willett WC, Rimm EB, et al. Light to moderate intake of alcohol, drinking patterns, and risk of cancer: results from two prospective US cohort studies. BMJ. 2015;351:h4238.