Black Women Have Higher Triple Negative Breast Cancer Risk (Why Aren’t We Doing Genetic Testing?)

Our risk of developing triple-negative breast cancer is higher in our community when we are under the age of 50. It accounts for approximately 15% of breast cancer diagnoses overall, according to researchers at The Mayo Clinic. Triple-negative breast cancer spreads more quickly than most other types and doesn’t respond well to hormones or targeted therapies.

But about 5-10% of breast cancers are thought to be genetic. Yet, there is not much discussion about genetic testing in our community. We have heard about the BRAC-1 and BRAC-2 gene mutations, but did you know that we all have those genes? BreastCancer.org says, “The function of the BRCA genes is to repair cell damage and keep breast, ovarian, and other cells growing normally. But when these genes contain mutations that are passed from generation to generation, the genes don’t function normally, and breast, ovarian, and other cancer risk increases.” These mutations account for 1 in 10 breast cancer diagnoses.

Robert Leone Ferre, MD, an oncologist at the Mayo Clinic who is studying triple-negative breast cancer, says, “It’s a bit more common at younger ages and in African American women, Hispanic women, and women of Indian descent. We also see this subtype more commonly in women who have a genetic mutation predisposing them to breast cancer — the BRCA1 mutation, in particular.”

Research by the American Cancer Society examined the need for genetic counseling to assess our risk for breast cancer and concluded that we need it as much as white women. There is limited data on those of us whose ancestors come from Africa.

The report says, “Genetic testing, counseling, and treatment refinement could benefit AA women. AA women have a higher incidence of breast cancer before age 50, a higher incidence of estrogen receptor (ER)-negative breast cancer and triple-negative breast cancer, a more frequent family history of ovarian cancer, and a 42% higher breast cancer death rate than White women.”

Since there was a knowledge gap, the researchers turned to the United States-based Cancer Risk Estimates Related to Susceptibility (CARRIERS) consortium. They reviewed data from 5,504 AA women with breast cancer and 4,993 AA women without breast cancer from 10 epidemiologic studies (including the American Cancer Society (ACS) Cancer Prevention Studies, CPS-II, and CPS-3).

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.

The researchers looked in the data from AA women for pathogenic mutations in the 12 genes associated mostly with European ancestry. They found:

• Among the 23 genes tested in this study, pathogenic mutations were identified in 8% of AA women who had breast cancer and 2% who did not.
• Mutations in BRCA1, BRCA2, and PALB2 were linked with high risks of developing breast cancer.
• The frequency of pathogenic mutations was especially high (10%) in AA women with ER-breast cancer (triple-negative breast cancer).

So why aren’t more of us undergoing genetic testing? Many used to believe that it didn’t apply to us because we are often diagnosed at a younger age. However, this study found that finding out whether “a woman has certain cancer predisposition genes is, in fact, highly predictive of the development of breast cancer in Black women.” But the reason we are not widely exploring these options is because our physicians don’t recommend them and our limited access to care.