Breast cancer targeting HER2: mechanisms, resistance, and emerging therapies

The human epidermal growth factor receptor 2 (HER2) is a member of the ErbB family, a group of four transmembrane glycoproteins with tyrosine kinase activity that are structurally related to the epidermal growth factor receptor (EGFR). These proteins are crucial in cell signaling processes that regulate normal cell growth and differentiation. When these signaling pathways become dysregulated, abnormal cell growth can occur, potentially leading to cancer. HER2 was first recognized as a key therapeutic target in breast cancer and has since been studied in the context of other cancers. This review provides an in-depth overview of HER2-targeted therapies and their mechanisms, as well as an analysis of the resistance pathways associated with these treatments. Over the past few decades, the development of HER2-targeted therapies has revolutionized cancer treatment strategies. Advances in understanding HER2 biology, resistance mechanisms, and diagnostic techniques have driven the field forward. This review concludes by discussing emerging anti-HER2 therapies that show great potential in the future treatment of cancer.