Efficacy of Neoadjuvant Endocrine Therapy Versus Neoadjuvant Chemotherapy in ER-positive Breast Cancer: Results From a Prospective Institutional Database.

Background: Although neoadjuvant chemotherapy (NACT) has been established as a standard for medically fit patients with locally advanced breast cancer, there has been renewed interest in utilizing neoadjuvant endocrine therapy (NET) for women with estrogen receptor-positive, human epidermal growth factor receptor 2-negative breast cancer. Rates of pathologic complete response (pCR) are known to be low, but data regarding down-staging and long-term outcomes are inconsistent.

Patients And Methods: A prospective institutional database of patients with breast cancer treated with neoadjuvant therapy from 2012 to 2017 was analyzed to identify patients with estrogen receptor-positive, human epidermal growth factor receptor 2-negative breast cancer.