What is HER2?
HER2+ Breast Cancer
Studies show that approximately 25% of breast cancer patients have tumors that are HER2+. HER2 stands for Human Epidermal growth factor Receptor 2. It is very important to find out your cancer’s HER2 status. This is because HER2+ tumors tend to grow and spread more quickly than tumors that are not HER2+. In addition, the treatment of HER2+ breast cancer is different than the treatment of breast cancer that is not HER2+. Women who are uncertain of their cancer’s HER2 status should talk to their doctor.
HER2+ breast cancer is aggressive, so it is important to find out your cancer’s HER2 status.1-3 This can help your doctor choose which treatments may be right for you.
How is HER2 positive breast cancer different?
HER2 stands for Human Epidermal growth factor Receptor 2. Each normal breast cell contains copies of the HER2 gene, which helps normal cells grow. The HER2 gene is found in the DNA of a cell, and this gene contains the information for making the HER2 protein. 4
The HER2 protein, also called the HER2 receptor, is found on the surface of some normal cells in the body. In normal cells, HER2 proteins help send growth signals from outside the cell to the inside of the cell. These signals tell the cell to grow and divide. 4
In HER2+ breast cancer, the cancer cells have an abnormally high number of HER2 genes per cell. When this happens, too much HER2 protein appears on the surface of these cancer cells. This is called HER2 protein overexpression. Too much HER2 protein is thought to cause cancer cells to grow and divide more quickly. This is why HER2+ breast cancer is considered aggressive. 1-3