Predictive biological factors for late survival in patients with HER2-positive breast cancer

The human epidermal growth factor receptor-2 (HER2) enriched subtype of breast cancer is associated with early recurrence, mostly within 5 years. However, anti-HER2 therapies have improved outcomes and their benefits persist in the long term. This study aimed to determine predictive factors for late survival in patients with HER2-positive breast cancer. We analyzed 20,672 patients with HER2-positive stage I–III breast cancer. The patients were divided into two groups based on a follow-up period of 60 months. The multivariate analysis of factors associated with poor overall survival included old age, advanced pathologic tumor size stage (pT), advanced pathologic regional lymph node stage (pN), high histological grade, presence of lymphatic and vascular invasion, and HR-negative status within 60 months. In the breast cancer-specific survival (BCSS) of the > 60 months follow-up group, the hazard ratios (HRa) based on pN-negative were 3.038, 3.722, and 4.877 in pN1 ( p = 0.001), pN2 ( p