The Human Epidermal Growth Factor Receptor 2 (HER2) oncogene is responsible for encoding a transmembrane tyrosine kinase which is over expressed in 20-25% of breast cancers and is associated with a worse prognosis. The use of trastuzumab, a humanized monoclonal antibody to the HER2 extracellular domain, has been shown to improve survival in both early and metastatic HER2-positive patients, and is now the standard of care in this patient population. Despite these advances, approximately 15% of patients treated with adjuvant trastuzumab will relapse, and progressive disease often occurs after first-line trastuzumab therapy in the metastatic setting within 12 months.
Last date updated on September, 2024