20–25% of cases of breast cancer (BC) are characterized by an overexpression of HER2, which is associated with a poor prognosis. Treatment with trastuzumab, a humanized monoclonal nti-HER2 antibody, in combination with chemotherapy (CT), significantly improves response rate, time to progression, and overall survival in HER2-positive women with metastatic BC. In women with resectable BC, trastuzumab improves disease-free and overall survival when used for 1 year in combination with or sequentially after chemotherapy. The positive results of trastuzumab therapy have prompted the search for other HER2-targeting drugs that can improve the therapeutic effects of trastuzumab in combination or when used sequentially. Pertuzumab is an experimental humanized monoclonal antibody directed to the dimerization domain of HER2. Because of their different binding pathways, trastuzumab and pertuzumab have complementary mechanisms of action. Pertuzumab is used in neoadjuvant and adjuvant systemic therapy for women with resectable or locally advanced BC, as well as in unresectable cases as palliative care.

Keywords: neoadjuvant and adjuvant therapy, HER2-positive breast cancer