Moreover, age (HR =1.034, 95% CI =1.020–1.049, p < 0.001), stage (HR =1.523, 95% CI =0.859–2.701 for TNM stage II, p = 0.150; HR =3.680, 95% CI =2.031–6.666 for TNM stage III, p < 0.001; HR =6.756, 95% CI =2.831–16.122 for TNM stage IV, p < 0.001) and tumour subtype (HR =1.544, 95% CI =0.873–2.733 for HR+/HER2+, p = 0.136; HR =1.32, 95% CI =0.539–3.236 for HR‐/HER2+, p = 0.543; HR =1.962, 95% CI =1.157–3.327 for HR‐/HER2‐, p = 0.012) were verified as independent prognostic variables in BC patients. The gene discussed is ERBB2; the disease is neoplasm.