ABSTRACT
Overexpression of the HER2 protein is exhibited by 20%–25% of breast cancers and is associated with an aggressive phenotype and increased risk of disease recurrence. Trastuzumab is a humanised monoclonal antibody which targets the fourth domain of the HER2 extracellular structure. Binding of trastuzumab to the HER2 protein reduces cell proliferation via interruption of cell-signalling pathways and induces antibody-dependent cell-mediated cytotoxicity. The HERceptin Adjuvant (HERA) study investigated whether addition of adjuvant trastuzumab treatment to standard neoadjuvant or adjuvant (neo/adjuvant) chemotherapy improved clinical outcomes in women with HER2-positive early breast cancer.
