Sarah Cannon - August 13, 2019

Approximately every half hour, a woman in the U.S. is diagnosed with triple negative breast cancer (TNBC). What is TNBC? How is it different from other forms of breast cancer?

stephanie graff photo
Stephanie Graff, MD, Director of the Breast Cancer Program at Sarah Cannon Cancer Institute at HCA Midwest Health and Associate Director of the Breast Cancer Research Program at Sarah Cannon Research Institute
Here are 5 key facts to know about TNBC.

  1. Breast cancer is diagnosed based on the presence or absence of three receptors, which are drivers for the development and growth of breast cancer. These include estrogen receptor, progesterone receptor and HER2‐neu. Triple negative breast cancer is diagnosed when a woman’s pathology report indicates a negative result for all three.
  2. About 10-20% of breast cancers are found to be triple negative.
  3. TNBC occurs most frequently in women ages 40-50 (younger than the average age of diagnosis across other forms of the disease), African American women and Hispanic women, and those with BRCA1 mutations.
  4. TNBC is more aggressive than other forms of breast cancer, making it more likely to spread to other parts of the body and more likely to recur early after treatment.
  5. Significant advancements have been made in the development of hormonal therapies and HER2-targeted therapies, which work to interfere with drivers of breast cancer and slow the growth of cancer cells. Triple negative breast cancer is typically treated with a combination of therapies such as surgery, radiation therapy, and chemotherapy.
    In 2019, atezeolizumab, a form of immunotherapy targeting triple negative breast cancers with PDL1 mutations, was the first approved targeted therapy in metastatic triple negative breast cancer. Sarah Cannon participated in the clinical trial that led to the approval. Ongoing clinical trials are being conducted for more effective therapies for TNBC. Learn about Sarah Cannon’s clinical trial offerings.

“Triple negative breast cancer is a phrase that tells us what your cancer is not. Our hope is that some day in the near future we can determine what your cancer is,” said Stephanie Graff, MD, Director of the Breast Cancer Program at Sarah Cannon Cancer Institute at HCA Midwest Health and Associate Director of the Breast Cancer Research Program at Sarah Cannon Research Institute. “Some of the most exciting advancements are being made in TNBC research. Ongoing research is aimed at identifying potentially hundreds of markers that may ‘turn on’ triple negative breast cancer and design drugs to target those pathways. I encourage patients with triple negative disease to ask if there are any clinical trials available to them.”

For more information on breast cancer receptors and how breast cancer spreads, visit the Sarah Cannon breast cancer education pages at

American Cancer Society