Cancer patient

Triple negative breast cancer (TNBC) is an aggressive form of breast cancer. It’s more likely to spread to other parts of the body and to return after treatment. According to, TNBC accounts for 10 to 20% of all breast cancers.

To understand what makes this breast cancer different from and more aggressive than others, you have to look at the disease on a cellular level.

What Is TNBC?

To diagnose breast cancer, your doctor will take a sample of tissue from your tumor and examine it for three main proteins known as cancer cell receptors. Receptors determine what’s fueling cancer cell growth, such as the hormones estrogen and progesterone.

Breast cancer can have a combination of receptors. If you have TNBC, your cancer cells will test negative for the estrogen (ER) and progesterone (PR) receptors, plus the human epidermal growth factor receptor 2 (HER2). You’ll see your receptor status on the pathology report your doctor shares with you. If your cancer cells test negative for a certain receptor, it will read “[name of receptor]-negative.” For example, if you test negative for HER2, your report will read “HER2-negative.”

Symptoms of TNBC are the same as for any type of breast cancer: a lump or mass in the breast, nipple discharge, an inverted nipple, and breast redness or pain.

Treating TNBC vs. Other Breast Cancers

With other types of breast cancer, receptor status helps your doctor determine the most effective treatment. Each receptor has one or more targeted treatments that help destroy breast cancer cells and reduce the risk of the cancer returning. But TNBC doesn’t have receptors to attack, so there aren’t any targeted therapies.

According to experts at Susan G. Komen, about 70 to 80% of breast cancers are hormone receptor-positive, meaning they can be treated with hormone therapy that either lowers estrogen production or blocks estrogen receptors. Since TNBC is hormone receptor-negative, hormone therapy isn’t an effective treatment option. For the same reason, TNBC doesn’t benefit from therapies aimed at attacking the HER2 protein.

TNBC has a poorer short-term prognosis than other types of breast cancer. In people with early-stage TNBC, 50% see their breast cancer return and 37% die in the first five years after surgery, according to a report in the Journal of Oncology Practice. After five years, the difference in breast cancer recurrence between hormone receptor-negative and hormone receptor-positive tumors decreases and eventually evens out, according to Susan G. Komen. This is because TNBC can be successfully treated.

Triple negative breast cancer treatment often involves a combination of surgery, radiation, and chemotherapy (either before or after surgery, or both). The size of your tumor, the grade or aggressiveness of the tumor cells, and lymph node involvement are among the factors used to determine your specific treatment plan.

Are You at Risk for TNBC?

While anyone can develop TNBC, you may be more likely to be diagnosed with TNBC if:

  • You’re under age 50: TNBC is more common among younger people and women who are premenopausal. Women older than age 60 are more likely to be diagnosed with other types of breast cancer.
  • You’re Black American or Latina: Black women and Latina women are more likely to be diagnosed with TNBC.
  • You have an inherited BRCA1 mutation: TNBC accounts for some 70% of breast cancers in people with a BRCA gene mutation, according to If you’re age 60 or under and diagnosed with TNBC, it’s recommended that you get tested for BRCA gene mutations, according to Susan G. Komen.

Whatever your breast cancer diagnosis, the Magee-Womens Breast Cancer Program team can develop the best treatment plan for you. Contact us today by completing our online form or by calling 1-866-696-2433.