Pre-operative Endocrine Therapy

Pre-operative endocrine therapy can be used to down-stage large or locally advanced breast cancers in ER+ disease. In the last four decades, it has evolved from a treatment perceived as an alternative to surgery for those too unfit to undergo surgery or chemotherapy, to the present day where it is a valuable and valid option in the treatment of postmenopausal women with ER-rich (Allred score 7-8, or > 50% staining for ER) breast cancer. Emerging data from the metastatic setting is translating into neoadjuvant trials, utilising dual endocrine targeting or combinations of endocrine agents and other targeted drugs, including those acting against components of the PI3K pathway and the cell cycle. The routine use of peri-operative endocrine therapy in all ER+ tumours may help to yield important long-term prognostic information, and guide adjuvant endocrine therapy. Pre-operative endocrine therapy is an exciting and evolving area with emerging new approaches. In this review, established evidence and emerging data on its applications are discussed.