ERBB2 and neoplasm: Patients were split into three age subgroups (≤40, 41–60, and ≥61 years old), three lymph node status subgroups (N0, N1, and N2–N3), three tumor size subgroups (T1, T2, and T3–T4), and five molecular subtype subgroups (PAM50, luminal A, luminal B, HER2, basal-like, and normal-like).