Breast Cancer and Alcohol: an Association

Just as the frequency of binge drinking by young women reaches new heights comes the news that excessive alcohol consumption can lead to an increased risk of beast cancer. A presentation at the American Association for Cancer Research meeting gave the results of data from more than 184,000 postmenopausal women who were participating in a joint NIH-AARP study. During an average of 7 years’ follow-up, 70% of the women drank alcohol. There were 5,400-odd cases of invasive breast cancer, and of these, there were 1,641 women who were ER+/PR+, meaning they had receptors on their tumor cells that were estrogen and progesterone ‘positive’ – i.e. they had hormone-dependent tumors.

Compared with non-drinkers, ER+/PR+ women who took less than one drink a day, 1-2 drinks daily, or 3 and more drinks daily had an increased risk of breast cancer that amounted to increases of 7%, 32%, and 51%, respectively.

Now these numbers were not statistically significant, but it seems intuitively likely that a larger study would result in convincing evidence of a link. The increased risk was observed across different types of alcohol consumed, adding to the high level of suspicion. The researchers suggest that alcohol affects estrogen metabolism, which increases the risk of hormone-sensitive breast cancer.