HER2-zero breast cancer patients had a shorter OS than HER2-low breast cancer patients (median OS: 30.3 vs. 49.1 months, P = 0.0005; HR: 1.72, 95% CI 1.33–2.22, P < 0.001) in the overall population by KM analysis and multivariate Cox analysis. Here, ERBB2 is linked to breast carcinoma.