ESR1 and invasive ductal breast carcinoma: Of the study patients, 29 (63.0%) were premenopausal, 36 (78.3%) were ER-positive, 34 (73.9%) were PR-positive, 27 (58.7%) were Her-2-positive, 26 (56.5%) exhibited tumors with a high Ki-67 expression (≥14%), 18 (39.1%) had a low pretreatment NLR (<1.76), only 3 (6.5%) had triple-negative breast cancer (TNBC), 44 (95.7%) had invasive ductal carcinoma, which was the prevalent histology, and 5 (10.9%) exhibited tumors with a high grade (GIII).