ESR1 and invasive ductal breast carcinoma: Most of the patients were less than 50 years (61.3%, n = 765), premenstrual (63.6%, n = 794), infiltrating ductal carcinoma (96.6%, n = 1,205), moderately/poorly differentiated (97.4%, n = 1,215), T2 stage (64.4%, n = 804), ER positive (74.3%, n = 927), PR positive (69.6%, n = 868), and one involved axillary LNs (62.3%, n = 777).