Alcohol, Female Sex Hormones and Breasts

Alcohol may boost the libido and remove inhibitions. In the end, this may mean more sex. But there is nothing sexy either in a drunk woman, or in how the alcohol impacts her body. More specifically, her breasts, as revealed by a new research presented at the American Association for Cancer Research 2008 Annual Meeting, April 12-16.

Alcohol has been linked to breast cancer by various researches. One of the largest studies revealed that alcohol boosts the growth of the most common type of breast cancer (accounting for 70% of tumors, which are connected to the activity of both the estrogen and progesterone receptors (ER+/PR+)). Even moderate alcohol consumption (1-2 daily drinks) was enough, and higher consumption meant higher risk. Compared to abstinent women, those who drank three or more glasses of alcohol daily displayed up to a 51% increased risk of ER+/PR+ breast cancer.

"This suggests that a woman should evaluate consumption of alcohol along with other known breast cancer risk factors, such as use of hormone replacement therapy," said first author, Jasmine Q. Lew, a fourth-year medical student at the University of Chicago.

The research did not connect alcohol to other breast cancer tumor types. Alcohol was already known to spur the quantities of estrogen metabolites inside a woman's body, the main trigger for hormone-sensitive breast cancer cells. Still, few studies focused on alcohol's effect on tumor type.

The team used data gathered by the NIH-AARP Diet and Health Study, which started in 1995. The poll was made of 184,418 postmenopausal women who completed questionnaires investigating their daily alcohol consumption. The subjects were followed-up for seven years and 70% of them drank alcohol; the average quantity was a little less than a drink daily. Even moderate drinking boosted the risk of developing breast cancer.

The researchers detected 5,461 cases of invasive breast cancer, but only in 2,391 of these subjects they had detailed data: 1,641 were ER+/PR+, 366 ER-/PR-, 336 ER+/PR-, and 48 ER-/PR+. The ER+/PR+ individuals presented a more powerful connection to alcohol consumption than that observed in the overall group.

Women who drank less than one drink daily, one to two drinks, and three or more daily drinks experienced an increase in the ER+/PR+ breast cancer risk by 7%, 32%, and 51%, compared to the abstinent women. There was an increased risk also among the women with ER+/PR- breast cancer, but much smaller and not statistically significant. The higher risk of invasive breast cancer was not connected with a specific type of alcoholic beverage.

"Our study at this point provides evidence for the notion that alcohol affects estrogen metabolism, which increases risk of hormone sensitive breast cancer," said Lew.