Neoadjuvant Treatment in Breast Cancer

Neoadjuvant (preoperative) therapy, initially developed to render primary inoperable tumors, is increasingly being delivered in patients with smaller lesions and particularly in patients with human epidermal growth factor receptor 2 (HER2)-positive and triple-negative breast cancer (TNBC). The neoadjuvant approach offers the advantages of downstaging the tumor and axilla, allowing for less extensive surgery, reducing postoperative complications, and evaluating the efficacy of therapy in vivo. Pathologic complete response (pCR) has been accepted as a primary endpoint in a number of neoadjuvant trials. This chapter provides a summary of the knowledge gained thus far from neoadjuvant trials conducted in breast cancer and discusses the current treatment recommendations and future research and trends.