Cape Town, South Africa—Breast density, which can affect the visualization of mammography, is one of the strongest and most consistent risk factors for breast cancer. Women with the highest mammographic density (≥75%) are at a 4- to 6-fold increased risk for developing breast cancer compared with women with the least dense tissue.
Although an estimated 50% of women in the United States have dense breasts, data on ethnic variations in breast density and breast cancer risk are limited. Research on this topic has seldom included minorities, such as black and Hispanic women, according to a group of researchers at Georgetown University in Washington, DC.
The team, led by Bridget Oppong, MD, Assistant Professor of Surgery, Division of Breast Surgery, Georgetown University Hospital of Surgery, Washington, DC, conducted an investigation into the differences in breast cancer risk among varying ethnic populations and presented the results in a poster at the American Association for Cancer Research International Conference on New Frontiers in Cancer Research.
The researchers reviewed breast density recorded at initial mammographic screening in women who presented to the Capital Breast Care Center and Georgetown University Hospital from 2010 to 2014. From imaging reports, they recorded the American College of Radiology BI-RADS density categories; 1, fatty; 2, scattered fibroglandular densities; 3, heterogeneously dense; and 4, extremely dense.
From 2010 to 2014, mammographic density was recorded for 2147 women: 940 (43.8%) black, 893 (41.6%) Hispanic, and 314 (14.6%) white. The investigators observed high breast density (categories 3 and 4) in Hispanic, premenopausal, nonobese women without children (P <.001), and found that these characteristics were predictive of high mammographic density. Obese women were 70% less likely to have high breast density than nonobese women.
In this analysis, Hispanic women were found to have the highest breast density, followed by black women, with white women having the lowest. The breast density and cancer interplay may be a crucial element in addressing racial and ethnic disparities in breast cancer outcomes, but further investigation of the impact of obesity on breast density in the understudied Hispanic population is needed.
“As there is a paucity of reporting on mammographic density in minority women, these data presented are valuable, especially as we are able to have a comparison group of whites,” the researchers noted.