only marginally significantP = 0.051
Univariate Cox analysis demonstrated that HER2-positive patients had better BCSS than HER2-low patients (hazard ratio = 0.422, 95% confidence interval [CI] = 0.199–0.892, P = 0.024), while the survival difference between the HER2-zero and HER2-low groups was only marginally significant (HR = 1.797, 95% CI = 0.997–3.239, P = 0.051).