How is the HER2+ type of breast cancer different from other cancers?
A specific type of breast cancer called HER2+ (HER2-positive) is caused by an excess of HER2 genes or by over-production of its protein, the HER2 cell surface receptor. HER2 is a member of the epidermal growth factor receptor (ErbB) family of genes which code for protein products known as surface-bound tyrosine kinase proteins. Mutations or over-production of these molecules stimulates cell division and uncontrolled growth. Twenty to 25 percent of breast cancers are HER2+. These tumors tend to grow faster and are generally more likely to recur than tumors that do not overproduce HER2. 3. What drugs are available to treat HER2+ breast cancer? There are two targeted agents that are U.S. Food and Drug Administration (FDA) approved for the treatment of HER2+ breast cancer: • Herceptin (trastuzumab), a drug developed in 1990s to target HER2+ breast cancer, consists of large antibodies that once injected into patients, latch on to the portion of the HER2 protein that sits on the outer surfac
