Triple-Negative Breast Cancer
Triple-negative breast cancer (TNBC) is breast cancer that does not have progesterone or estrogen receptors and does not produce much, if any, of the HER2 protein. This may be called ER/PR negative and HER2 negative.
- TNBCs account for around 10-15% of all breast cancers.
- It is more common in individuals who are BRCA1 positive or pre-menopausal, and in African-American women.
- Breast cancers in Latina women have a higher likelihood of being triple-negative.
- Some cancers are fueled by estrogen, progesterone or HER2. TNBC is not.
- TNBC can be more aggressive and recur more frequently than other breast cancers. However, the size and extent of the cancer also play a big role in how well the treatment will work.
How is TNBC diagnosed?
- After a breast biopsy or surgery, a sample of the tumor is tested for the presence of hormone receptors and HER2. The result is reported in your pathology report.
- If the sample is negative for hormone receptors and HER2, the cancer is triple-negative.
- Determining the subtype of your breast cancer is important for treatment planning.
How is TNBC treated?
- Chemotherapy, radiation, and surgery are most often used to treat triple-negative breast cancers.
- Research has found having chemotherapy before surgery (called neoadjuvant) works better for treating TNBC.
- Hormone therapy and HER2 targeted therapies are used to treat some breast cancers but are not used in the treatment of TNBC. TNBC tumor cells do not have the receptors that these medications work on.
- Individuals with advanced or stage IV TNBC who have a BRCA 1 or 2 mutation may also be treated with targeted therapies called PARP inhibitors including olaparib and talazoparib.
- Individuals with advanced or stage IV TNBC will also be tested for the presence of PD-L1 proteins. If these are present in the cells, the cancer may be treated with the immunotherapy medication atezolizumab in combination with chemotherapy.
How can I manage this diagnosis?
- While the diagnosis of TNBC may be challenging, remember there are many treatment options.
- Learn about TNBC. This can help you ask questions at your oncology visits and feel more in control of your treatment decisions.
- Seek out support groups specific to TNBC. There are several online groups and websites (see resources below).
- All cancers are unique and you should not compare your experience to others.
Resources for More Information
Triple-Negative Breast Cancer Foundation
Offers education, support/helpline, and online forum.
Living Beyond Breast Cancer
Offers education and a “buddy” program that can match you with another woman who has had a diagnosis of TNBC.
Collignon, J., Lousberg, L., Schroeder, H., & Jerusalem, G. (2016). Triple-negative breast cancer: treatment challenges and solutions. Breast Cancer: Targets and Therapy, 8, 93.
Kumar, P., & Aggarwal, R. (2016). An overview of triple-negative breast cancer. Archives of gynecology and obstetrics, 293(2), 247-269.
Rey-Vargas, L., Sanabria-Salas, M. C., Fejerman, L., & Serrano-Gómez, S. J. (2019). Risk Factors for Triple-Negative Breast Cancer among Latina Women. Cancer Epidemiology and Prevention Biomarkers, 28(11), 1771-1783.