What is triple negative breast cancer?

After a breast cancer diagnosis, breast cancers are checked for three proteins — estrogen and progesterone receptors and HER2 — often linked to breast cancer. Triple negative breast cancer is a breast cancer that tests negative for these three proteins. This can make the cancer harder to treat.

Triple negative breast cancers are more often found in women under age 40 and in women with a BRAC1 mutation (a gene that is passed in families). They are also more likely to grow and spread fast. About 10 to 15% of all breast cancers are triple negative.

What are the symptoms of triple negative breast cancer?

Like other breast cancers, the most common symptom is a lump in the breast. Other symptoms may include:

  • A change in the shape of the breast
  • Discharge (not breastmilk) from the nipple
  • Pain in the breast or nipple
  • A dimpling in the skin on the breast
  • In many cases, breast cancer is found on a mammogram test.

How is triple negative breast cancer treated?

Treatment for triple negative breast cancer may include:  

  • Surgery to remove the tumor (lumpectomy) or, in some cases, the entire breast (mastectomy)
  • Chemotherapy to shrink the tumor or help kill any cancer cells that have spread to other parts of the body
  • Radiation therapy to help destroy any cancer cells left in the breast

What are the risk factors for triple negative breast cancer?

Specific risk factors for triple negative breast cancer include:

  • Having an inherited BRAC1 mutation
  • Being a Black or Latina woman
  • Being under age 40