Links Between Alcohol Consumption and Breast Cancer

A Look at the Evidence

Ying Liu; Nhi Nguyen; Graham A Colditz


Women's Health. 2015;11(1):65-77. 

In This Article

Conclusion & Clinical Implications

Moderate alcohol consumption is consistently associated with increased risk of breast cancer, particularly hormone receptor-positive subtypes. Given the increased susceptibility of breast tissue to tumorigenesis between menarche and first pregnancy and the high prevalence of alcohol use in adolescent girls and young women, understanding how alcohol intake before first pregnancy influences breast cancer development is important for breast cancer prevention. Women should understand the accumulation of risk across the life course and the lifelong increase in risk of breast cancer from moderate and heavy consumptions in early adult years. We have reported that the risks of breast cancer and proliferative BBD are increased by 11 and 16% for one drink/day alcohol intake before first pregnancy when breast tissue is likely at its most vulnerable stage. This translates into 4% of breast cancer cases and 11% of proliferative BBD cases attributable to alcohol consumed before first pregnancy, the estimates controlled for alcohol consumed after first pregnancy. Breast cancer prevention efforts should not only target midlife and older women, but also include adolescent girls and young women. Healthcare providers should be aware of the adverse effect of youth drinking on a woman's lifelong risk of breast cancer and provide behavioral counsels to their patients.

The US Preventive Services Task Force recommends that clinicians screen adults aged 18 years or older for alcohol misuse and provide persons engaged in risky or hazardous drinking with brief behavioral counseling interventions.[147] This general recommendation, such as the WHO recommending limited intake, misses the critical importance of adolescent and early adult alcohol intake among women. The available evidence is insufficient to assess screening and behavioral counseling interventions in primary care settings to reduce alcohol misuse in adolescents. However, greater attention by primary care physicians and other health professionals to identifying and preventing underage drinking remains a priority, as adolescents today will experience breast cancer over the coming 50 years.

Alcohol may be involved in breast tumor initiation and promotion through increasing sex hormone levels, enhancing breast epithelial cell responsiveness to sex hormones, producing genotoxic metabolite acetaldehyde and oxidative stress. Recent in vitro studies suggest that alcohol stimulates migration and invasion of breast cancer cells through interfering with the epithelium–stroma interaction and enhancing EMT. Aberrant patterns of DNA methylation also could be part of the pathogenic mechanisms that lead to alcohol-induced cancer development.

Despite a dose-dependent association between alcohol and breast cancer risk, it remains unclear about a threshold level of alcohol consumption above which the increased risk of breast cancer becomes clinically significant. Moderate alcohol consumption appears to reduce the risk of developing or dying from heart disease, the leading cause of death in the USA. This cardiovascular benefit is observed primarily in middle-aged and older people. There is paucity of data regarding the association between alcohol intake and cardiovascular health in young adults. A pooled analysis of eight prospective studies including more than 190,000 women showed a lower risk of coronary heart disease for low-to-moderate alcohol intake in young women (age <50 years).[148] The beneficial effect in young women might be negligible due to their low absolute risk for coronary heart disease. Healthcare providers should discuss with their patients about drinking habits as well as weighing the risk and benefit of low-to-moderate alcohol intake. The 2010 US Dietary Guidelines for Americans recommends that adult women who consume alcohol should limit their exposure to no more than one drink per day. Given a small, but significant, association between light and moderate alcohol intake and breast cancer risk, the recommended amount of alcohol may be inappropriate for some women in terms of potential breast cancer risk. Improved understanding of breast cancer risk accumulation and provider guidance on risk of breast cancer can lead to reductions in alcohol intake during the critical period of breast cancer risk accumulation and lower lifelong risk for breast cancer.