Women of color and young women may face elevated risks of developing triple-negative breast cancers, a new study reports.
Triple-negative breast cancer spreads more quickly than most other types and doesn’t respond well to hormone or targeted therapies.
Previous US studies have found racial disparities in triple-negative breast cancer diagnoses, but few have looked beyond the scope of one state. For the current study, researchers analyzed all breast cancer cases diagnosed during 2010–2014 from the United States Cancer Statistics database, a surveillance system of cancer registries with data representing 99 percent of the US population.
Comparing triple-negative breast cancer cases
The team identified more than 1.15 million cases of breast cancer, with triple-negative cases accounting for about 8.4 percent of all cases and discovered a significant incidence of triple-negative breast cancer for women of color, specifically non-Hispanic black women, and for younger women.
Compared with non-Hispanic white women, non-Hispanic black women and Hispanic women had higher odds of being diagnosed with triple-negative breast cancer, respectively. More than 21 percent of non-Hispanic black women were diagnosed with triple-negative breast cancer, compared with less than 11 percent for all other types of breast cancer.
Women younger than 40 years of age had twice the odds of a triple-negative breast cancer diagnosis than women aged 50–64 years. Also, among women diagnosed with breast cancer, those diagnosed at late stages were 69 percent more likely to have triple-negative cancer than other types.
“Our results demonstrate that African American women of younger age are more likely to be diagnosed with triple negative breast cancer than younger women of other ethnicities,” says Dora Il’yasova, epidemiologist and associate professor in the School of Public Health at Georgia State University.
Because of the aggressive nature of triple-negative breast cancer and the lack of therapeutic options, it is important to know which individuals face a higher risk and what factors may influence this risk, the researchers note.
Know your history
“Until we have evidence of what environmental and genetic components contribute to this risk, it is imperative that women know their familial history of breast cancer, discuss that with their physicians and follow screening recommendations,” says lead researcher Lia Scott, a recent doctoral graduate of the School of Public Health.
“We hope that this update on the epidemiology of triple-negative breast cancer can provide a basis to further explore contributing factors in future research.”
According to the American Cancer Society, most breast cancers are mainly classified by three proteins that can affect the cancer’s growth: the estrogen hormone receptor, the progesterone hormone receptor, and the human epidermal growth factor receptor 2.
Triple-negative breast cancer does not have any of the receptors, making it difficult to identify what is fueling the cancer’s growth. Doctors have fewer options for targeted treatment to destroy these cancer cells. Chemotherapy is still an effective option for treating this cancer and reducing the risk of its return.
Additional coauthors are from Georgia State and the University of North Carolina’s Lineberger Comprehensive Cancer Center. The National Institute on Minority Health and Health Disparities of the National Institutes of Health funded the work, which appears in Cancer.
Source: Georgia State University