A new study in an American Association for Cancer Research medical journal challenges the notion that alcohol consumption alone is a major risk factor for breast cancer in post-menopausal women. The risk grows substantially when women undertake hormone replacement therapy: The study found a 60 percent greater risk for women who drink while undergoing the therapy compared with women who drink alcohol responsibly and aren't on hormone replacement.
"Both hormone therapy—particularly the combined estrogen-plus-progesterone (EPT)—and alcohol have been linked to breast cancer," said lead author Pamela Horn-Ross, a researcher with the Cancer Prevention Institute of California. And the researchers noted a "non-significant increased risk" among women who never used hormone therapy but still drank alcohol. "EPT increases risk more than moderate alcohol consumption (about one drink per day) and our paper suggests that moderate alcohol consumption may not adversely impact breast cancer risk in the absence of EPT," Horn-Ross told Wine Spectator.
Horn-Ross and her team relied on data from the California Teachers Study, which followed more than 130,000 post-menopausal women for a period of 10 years. Their study, slated for publication in Cancer Epidemiology, Biomarkers & Prevention, pulled data from 40,000 of those women. Of those, 660 were diagnosed with invasive breast cancer during the 10 years. Data on their drinking habits were also recorded, as well as participation in hormone replacement therapy, which is used as a treatment for symptoms associated with menopause.
Horn-Ross also suggested that the responsible consumption of alcohol may have other upsides for women. "Moderate alcohol consumption may reduce the risk of heart disease, which is more common among women than breast cancer is," she said.
The subject of alcohol's role in the pathology of breast cancer is hotly contested in the medical industry. The latest study will not lessen those flames. Dr. Harvey Finkel, an oncologist at Boston University Medical Center, reviewed the study as part of critical work with the International Scientific Forum on Alcohol Research. "The role of alcohol in the genesis of breast cancer has continued to be confusing, even conflicted," he said.
"There must be subsets of individuals not yet precisely dissected out that contribute to the differences among the results from epidemiologic studies," he added. "One could hope that studies such as the present one will help, although we are clearly not nearly ready to write down a standard theory."