ESR1 and neoplasm: Basing on recent studies, the main risk factors for BM development are: young age (<40 years), tumor diameter > 5 cm, high tumor grade (> BM for grade 3 tumors vs. grades 1 and 2), lobular histotype, four or more positive lymph nodes, hormonal status (e.g., positive outcome for patients with positive estrogen receptors, negative outcome for high expression of androgen receptors) and molecular profile (Lee et al., 2011; Harries et al., 2014; Feng et al., 2017; Xiao et al., 2018; Zhang et al., 2018).