Addressing the future: combination with targeted therapies, adjuvant setting and beyond.

The potential mechanisms of de novo and acquired resistance to endocrine therapy are increasingly being understood and potential treatment options that offer a therapeutic alternative in patients exhibiting resistance are being explored. Any efforts directed towards improving patient outcomes beyond aromatase inhibitors (AIs) in the adjuvant setting are likely to be focused on blocking endocrine and other pathways simultaneously, either upfront or in sequence. In particular, targeted therapies either alone or in combination with AIs may improve clinical outcomes--the results of ongoing clinical trials will shape the future treatment of breast cancer.