Alcohol Linked to Increased Risk of Breast Cancer in African-Americans

   Alcohol consumption was associated with an increased risk of breast cancer in an extensive study of African-American women, indicating that they, like white women, may benefit from limiting alcohol. These study results have been published in Cancer Epidemiology, Biomarkers & Prevention, the American Association for Cancer Research journal. The lead author is Melissa A. Troester, Ph.D., a professor of epidemiology and director of the Center for Environmental Health and Susceptibility in the Gillings School of Global Public Health at the University of North Carolina (UNC).

     “Alcohol is an important modifiable exposure, whereas many other risk factors are not,” explained senior study investigator Melissa Troester, Ph.D., professor of epidemiology and director of the Center for Environmental Health and Susceptibility in the Gillings School of Global Public Health at UNC. “Women who are concerned about their risk of breast cancer could consider reducing levels of exposure.”

   In this new study, the researchers wanted to discern whether alcohol raises the risk for African-American women by assessing participants in an extensive survey that solely enrolled African-American women. Dr. Troester and her colleagues enrolled 22,338 women from the African American Breast Cancer Epidemiology and Risk (AMBER) Consortium, which encompasses four extensive epidemiologic breast cancer studies. The study participants reported their alcohol intake via a questionnaire, and researchers used logistic regression analysis to estimate the association between alcohol consumption and breast cancer cases.

       The analysis showed that women who drank seven or more drinks per week showed an increased risk of almost all subtypes. Moreover, women who drank 14 or more alcoholic beverages per week were 33% more likely to develop breast cancer than women who consumed four or fewer drinks per week.

       Interestingly, the researchers found that black women drink less alcohol than white women, with previous research suggesting various reasons, from religious restrictions to health restrictions. In this study, 45% of the women were “never drinkers,” and researchers found that the “never drinkers” were more likely to develop breast cancer than the light drinkers. Dr. Troester stated they did not identify the causes for increased risk in never-drinkers. Still, previous studies found the similarly elevated risk in never-drinkers implicates the co-morbidities, such as diabetes, that influenced them to avoid alcohol.

       While the research team noted that a limitation of the study was that it included relatively few women who drank heavily, making those findings less statistically significant, they did point out that their results were consistent with previous research indicating increased risk for the highest levels of alcohol consumption. Furthermore, the results of this study suggest that the same risk factors documented in previous research apply to black women as well.

    “Understanding the impact of these various risk factors could help narrow the disparity in breast cancer incidence and mortality,” Dr. Troester concluded.