Triple-Negative Breast Cancer Risk Factors

Updated 
August 31, 2015

Researchers are still learning why some women are more likely than others to develop triple-negative breast cancer. Research suggests that genes, age, race and ethnicity are risk factors.

Breast Cancer Gene Mutations

Everyone has BRCA1info-icon and BRCA2info-icon genes, which we get from our mother and father. When they work properly, these genes prevent the development of cancers. But a small percentage of people with breast cancer are born with a mutationinfo-icon, or error, in BRCA1 or BRCA2.

If you are born with a BRCA1 or BRCA2 geneinfo-icon mutation, you are at increased risk for developing breast, ovarianinfo-icon and other cancers throughout your life. The BRCA1 mutation puts you at higher risk for developing a basal-like breast cancer, such as triple-negative breast cancerinfo-icon. Scientists are still trying to find out why.

Keep in mind, not all breast cancers from BRCA mutations are triple-negative. In fact, BRCA2 mutations are more likely to be present in estrogen receptor-positiveinfo-icon breast cancers.

If you have a family history of breast cancer, you and your relatives could carry a BRCA1 or BRCA2 mutation. You could also be the first person in your family known to develop breast cancer because of a BRCA mutation. Knowing your BRCA status can help you and your doctors discuss an effective treatment plan and learn ways to reduce your risk for recurrenceinfo-icon. A geneticinfo-icon counselor can talk with you about genetic testing.

Age, Race or Ethnicity

Studies suggest that being premenopausalinfo-icon, African-American or Caribbean increases your risk of developing basal-like or triple-negative breast cancerinfo-icon. Among African-American women who develop breast cancer, there is an estimated 20 to 40 percent chance of the breast cancer being triple-negative.

Researchers don’t yet understand why premenopausal women (who tend to be younger), and women in some ethnic groups have higher rates of triple-negative breast cancer than other groups of women.