Neoadjuvant endocrine therapy in breast cancer

The use of endocrine therapy is well established as a primary treatment for locally advanced breast cancer. However, despite the current popularity of neoadjuvant chemotherapy for operable tumours, there is relatively little published evidence for pre-operative endocrine therapy in operable disease, particularly outside of the elderly population. The wider use of aromatase inhibitors (AIs) has encouraged studies that compare the efficacy of AIs with tamoxifen in the neoadjuvant setting, but there remains a lack of comparison of neoadjuvant with adjuvant endocrine therapies. This review discusses the current evidence regarding primary endocrine therapy, along with the factors involved in choosing appropriate patients for neoadjuvant therapy and the current opinions on length of treatment time and measurement of response prior to surgery.