Before talking about what triple-negative breast cancer is, you have to understand receptors, proteins that are found on the surface of many breast cancer cells. these receptors allow the cells to receive signals to grow.
Hormone receptors receive hormone signals from the hormones estrogen and progesterone. Approximately 75% of women with breast cancer have cancer cells that are estrogen-receptor-positive. About 65% have cells that are both estrogen- and progesterone-receptor-positive.
About 20-30% of breast cancers have too many HER2 (human epidermal growth factor receptor) receptors. These receptors receive signals that stimulate breast cancer cell growth. The more HER2 receptors the cancer cells have, the more likely breast cancer is to grow.
Around 10-20% of breast cancers are found to be triple negative. This means that in the lab, your cells tested negative for hormone receptors and HER2 receptors. As a result, the cancer won’t respond to hormonal therapy. It also won’t respond to medication used for HER2. It can, however, be treated with chemotherapy and radiation therapy.
Other facts:
- Triple negative breast cancer tends to be more aggressive than other forms of breast cancer.
- It tends to be higher grade than other types: the higher the grade, the less the cancer cells look like normal, healthy breast cells in appearance and growth patterns.
- It usually is a cell type called “basil-like”. This means the cells look like the basal cells that line the breast ducts. Basal-like cancers can be linked to family history or there can be none.
Why you should be concerned:
While anyone can get triple-negative breast cancer, researchers have found it is more likely to affect:
- Younger people. It is more likely to occur before the age of 40 and 50, unlike other types of breast cancer that usually occur at age 60 or older.
- African American and Hispanic women. African American women are most commonly affected, followed by Hispanic women.
- People with BRCA1 mutation. When people with this mutation develop breast cancer, particularly before age 40, it’s usually triple-negative.
For more information about triple-negative breast cancer, visit www.breastcancer.org
