Phase 2 randomized trial of primary endocrine therapy versus chemotherapy in postmenopausal patients with estrogen receptor-positive breast cancer.

Background: Few studies have compared primary neoadjuvant endocrine therapy with neoadjuvant chemotherapy in breast cancer patients. The need for preoperative chemotherapy with doxorubicin or taxanes may be reduced in postmenopausal patients with estrogen receptor (ER)-positive and/or progesterone receptor (PgR)-positive tumors. This randomized, controlled, phase 2 study evaluated the efficacy of neoadjuvant chemotherapy compared with endocrine treatment with aromatase inhibitors in postmenopausal women with ER-positive and/or PgR-positive breast cancer.