Role of trastuzumab in adjuvant therapy for locally invasive breast cancer

Purpose. The role of trastuzumab in adjuvant therapy for locally invasive breast cancer is discussed. Summary. Trastuzumab is a humanized monoclonal antibody that binds to the extracellular domain of human epidermal growth factor receptor-2 (HER2). Currently, trastuzumab is indicated for use in HER2-positive patients with metastatic breast cancer. Because trastuzumab specifically targets a receptor that is overexpressed in tumor cells, it is less likely to cause the cytotoxic adverse effects of traditional chemotherapy. Cardiotoxicity has been a major concern, however. Several trials were started to evaluate trastuzumab in the adjuvant setting in patients diagnosed with early-stage breast cancer. The interim results of these trials have shown a promising effect of adjuvant therapy with trastuzumab in improving overall survival, disease-free survival, relapse-free survival, and distant-disease-free survival. Conclusion. The use of trastuzumab as adjuvant therapy in patients with HER2-positive breast cancer can lead to increased survival. The appropriateness of trastuzumab therapy should be considered based on HER2 status, cost, and risk of toxicity.