ESR1 and neoplasm: The results reveal that the high PIV group (odds ratio (OR): 0.349, 95% confidence interval (CI): 0.149–0.778, p = 0.012), ER-positive (OR: 0.467, 95% CI: 0.220–0.972, p = 0.044), Her2-positive (OR: 4.529, 95% CI: 2.252–9.304, p < 0.001), tumor diameter > 5 cm (OR: 0.238, 95% CI: 0.077–0.715, p = 0.011), initial axillary lymph node stage 3 (OR: 0.269, 95% CI: 0.105–0.665, p = 0.005), and taxane-based chemotherapy (OR: 3.841, 95% CI: 1.848–8.215, p < 0.001) were identified as independent factors influencing the achievement of pCR after NAC (Table 3).