HER2-positive

HER2-positive refers to breast cancer cells that have an excess of a protein called HER2 (human epidermal growth factor receptor 2) on their surface. This overexpression promotes rapid cell growth and division, making the cancer more aggressive. About 1 in 5 breast cancers are HER2-positive. Identifying this type helps doctors choose targeted treatments, such as HER2 inhibitors, that specifically attack these cancer cells. Knowing the HER2 status is important for understanding the cancer’s behavior and planning effective therapy.