Alcohol and Breast Cancer - What's the Risk?

A recent publication from the Nurses' Health Study (Chen W et al, JAMA, 2011) has once again generated discussion regarding the association between alcohol and breast cancer risk. The observation of an association between alcohol intake and breast cancer is not new - what's caught the attention of the press and the public is that the current study reports that as few as three to six drinks per week can increase breast cancer  risk.

Numerous previous studies have reported that the association between alcohol and breast cancer risk is dose-dependent, and that the degree of risk falls along a linear continuum -- heavier levels of alcohol intake are associated with greater breast cancer incidence.  All of these studies have, by necessity, been observational and relied on self-reported alcohol consumption; we'll never have a study that randomizes people to differing levels of alcohol intake, for good reason. Some prior studies have reported that the effect of alcohol on breast cancer risk appears higher in women taking post-menopausal hormone replacement therapy (HRT). The Nurses' Health Study investigators, as well as others, have previously reported that folate is a potential moderator of the effects of alcohol on breast cancer risk, although that's not included in the current analysis (Zheng SM et al, Cancer Epidemiol Biomarkers Prev 2005).

How big is the increase in breast cancer risk in light drinkers? The accompanying editorial (Narod S et al, JAMA 2011) calculates that an average  woman who consumes one alcoholic drink per day would see her 10-year risk of developing breast cancer increase from 2.8 percent to 3.5 percent. For women with a higher baseline risk for breast cancer due to family history or other factors, the potential benefit from abstaining from all alcohol may be worth it. However, no data exists in any study to show that giving up alcohol after years of use will reduce breast cancer risk.

It's important to view the breast cancer risk associated with alcohol in the bigger picture of overall health. While a nightly glass of wine slightly increases breast cancer risk, it may very well result in a larger reduction in even more common health risks, including cardiovascular disease.   A recent meta-analysis on alcohol and cardiovascular disease concludes that light to moderate alcohol consumption, including levels of < 1 drink per day,  is associated with reduced risk of coronary heart disease and stroke. (Ronksley PE et al, BMJ 2011) For the average American woman, cardiovascular disease is a bigger health risk than breast cancer.

How do we put this all in perspective? I would never encourage a woman who doesn't consume alcohol to consider doing so for health purposes. And there are lots of issues associated with moderate-heavy alcohol consumption that should warrant recommendations against excessive alcohol intake. Each woman should consider the risks and benefits of alcohol consumption to make the best personal choice.

Encouraging a healthy lifestyle that includes physical activity, healthy diet, and maintaining a good body weight, as well as minimizing postmenopausal HRT use and alcohol intake, can help our patients take control of their modifiable breast cancer risk factors and optimize overall health and well-being.

Press Releases

Library of press releases about SCCA from the last three years.

Audio-interviews with SCCA Physicians

FAQs

Answers to common questions about SCCA and its parent organizations, Fred Hutchinson Cancer Research Center, UW Medicine and Seattle Children's.

Videos

Check out a library of videos about SCCA and the various cancers and treatments performed by doctors at our clinics.

SCCA Facts

A quick fact sheet for journalists and others about SCCA.