A University of Houston study has identified a gene that may account for the link between alcohol and breast cancer in some women.

"Alcohol consumption is prevalent among women in the U.S. and is a risk factor for breast cancer," said UH cancer biologist Chin-Yo Lin. "Our research shows alcohol enhances the actions of estrogen in driving the growth of breast cancer cells and diminishes the effects of the cancer drug Tamoxifen on blocking estrogen by increasing the levels of a cancer-causing gene called BRAF."

Lin’s findings, reported in the Public Library of Science journal PLOS ONE, offer new clues to why alcohol boosts the risk of breast cancer for some women. Federal health guidelines recommend most women have no more than one drink per day — for men, it’s two per day — because of such risks.

It is estimated that tens of thousands of breast cancer cases each year are attributable to alcohol consumption and that drinking is also associated with an increased risk of disease recurrence in women with early stage breast cancer.

The study findings indicate that alcohol increases estrogen-induced tumor growth and that there is a direct link between alcohol, estrogen, and a cancer-causing gene. The researchers suggest the finding may help identify women most at risk and prevent cancer.

"We hope these and future findings will provide information and motivation to promote healthy behavioral choices, as well as potential targets for chemoprevention strategies to ultimately decrease breast cancer incidents and deaths within the next decade," Lin said.

"We want to provide women, in general, with more information and insight to be better able to balance their consumption of alcoholic beverages with the potential health risks, including cancer patients who may want to take into consideration the potential detrimental effects alcohol consumption might have on treatments and modify their behavior and habits accordingly."