NR4A1 and breast carcinoma: For this reason, two large ongoing trials are of particular interest: the CAN-NCIC-MA27 study and its companion study, evaluating BMD in postmenopausal women who have primary breast cancer that is treated using exemestane or anastrozole, and the Femara Anastrozole Clinical Evaluation study, a comparison of letrozole with anastrozole in the treatment of postmenopausal women with hormone-receptor-positive and node-positive breast cancer.