Optimizing Endocrine Therapy for Breast Cancer.

Endocrine therapy has significantly improved outcomes for patients with early- and advanced-stage hormone-receptor (HR)-positive breast cancer. Despite the success of adjuvant endocrine therapy, some patients with early-stage disease will experience relapse. Additionally, all patients with advanced disease will eventually experience disease progression on endocrine therapy due to resistance. Improved understanding of the mechanisms associated with resistance to endocrine agents has recently led to the approval of new therapeutics. Multiple questions remain unanswered, including the optimal duration of adjuvant therapy, the role of ovarian ablation in early-stage breast cancer in premenopausal women, and how to best incorporate targeted agents with endocrine therapy in the metastatic setting. This article reviews the optimization of endocrine therapy in patients with HR-positive breast cancer, focusing on these controversial areas.