Endocrine therapy as adjuvant or neoadjuvant therapy for breast cancer: selecting the best agents, the timing and duration of treatment.

Hormone receptor (HR) positive breast cancers represent the vast majority of breast cancers. Adjuvant and/or neoadjuvant endocrine therapy is highly effective and appropriate for nearly all women with HR positive tumors. Adjuvant tamoxifen (TAM) is a major endocrine treatment option, which has been found to be effective in both premenopausal and postmenopausal patients. Considerable evidence has been accrued of a benefit for ovarian ablation or suppression (OA/S) in premenopausal patients, for aromatase inhibitors (AIS) in postmenopausal patients, for the longer duration of adjuvant endocrine therapy and for the clinical utility of neoadjuvant endocrine therapy. Clinical practice guidelines should keep changing with developing evidence-based practice guidelines pertaining to breast cancer care. The present publication conducted a comprehensive systematic review of the literature addressing the use of endocrine therapy as adjuvant or neoadjuvant therapy for HR positive breast cancer, focusing on selecting the best agents for both premenopausal and postmenopausal patients, as well as the optimal duration of such treatment.