Gene Regulation May Influence Racial Disparities in Breast Cancer Survival

In the United States, African American (AA) women are more likely than European American (EA) women to die from breast cancer, although EA women are more likely to get diagnosed with the disease. The survival gap is widest among women with breast cancer that is associated with receptors for hormones causing the uncontrolled growth of breast cells. Researchers found that genetic markers expressed in breast tissue could potentially be used to predict breast cancer survival based on race.

The study included breast tissue samples from 262 AA and 293 EA women who had surgery for breast cancer between 2001 and 2010 at a medical center in North Carolina. Medical records provided self-reported race/ethnicity data and survival data. The researchers analyzed the pattern of genes expressed in the breast tissue samples.

As in previous studies, AA women had a higher frequency of triple-negative breast cancer, compared with EA women. Triple-negative breast cancer is an aggressive type of cancer that has neither receptors for the two main sex hormones in women, estrogen and progesterone, nor for the HER-2 growth-promoting protein found on the outside of all breast cells. Without these receptors, the cancer is difficult to target and treat. A common place for breast cancer to arise is from the cells that line the milk ducts. The study found no significant racial difference in gene regulators associated with the development of these inner cells; however, the authors suggest that other factors in the genetic pathway in breast tissue might play a role in the worse breast cancer survival outcomes for AA women compared with EA women.

Breast cancer survival is influenced by many factors, including access to and quality of care. Nonetheless, the results of this study highlight genetic markers that clinicians may use to predict breast cancer survival based on race. The study also indicates potential targets for therapy and promotes further investigation to enable researchers to understand the biological processes that may contribute to racial disparities in breast cancer survival.

Citation:
Byun, J.S., Singhal, S.K., Park, S., Yi, D.I., Yan, T., Caban, A., . . . Gardner, K. (2020). Racial differences in the association between luminal master regulator gene expression levels and breast cancer survival. Clinical Cancer Research, 26(8), 1905–1914. https://doi.org/10.1158/1078-0432.CCR-19-0875

Page updated January 14, 2022