ERBB2 and breast cancer: In patients with human epidermal growth factor receptor 2-enriched breast cancer, the group with normal TC levels before NAC had significantly better OS than those with high TC levels (P = 0.013, log-rank test), and in patients with TNBC, the group with high TC levels after NAC had significantly better OS than those with normal TC levels (P = 0.014, log-rank test).