Targeting the HER2 receptor in metastatic breast cancer.

The advent of targeted therapies has revolutionized the treatment of certain types of cancer. Identification of molecular targets on cancer cells has led to the design of novel drugs, which either used as single agents or in combination with chemotherapy, has prolonged survival in metastatic disease, or contributed to curative treatment in the adjuvant setting. A literature review was conducted to identify and present current knowledge on the molecular function of the HER2 receptor, its role in the pathogenesis of breast cancer and anti-HER2 targeted drugs in use or under development. Many molecular targets have been identified in breast cancer, with the HER family of receptors being the ones most extensively studied. Trastuzumab and lapatinib target the HER2 receptor and are approved drugs for the treatment of metastatic breast cancer. Several other targeted agents, including T-DM1, pertuzumab, neratinib, afatinib and ertumaxomab, are currently being tested in vivo as well as in clinical studies. The use of targeted therapies in metastatic breast cancer has improved prognosis, increased survival and dramatically changed the way we treat breast cancer patients today.