ERBB2 and metastatic malignant neoplasm in the lymph nodes: Furthermore, multivariate analysis revealed that the mutations remained as a significant unfavorable factor for RFS (adjusted HR 2.81; 95% CI: 1.08–7.29; P = 0.035) and DRFS (adjusted HR 3.60; 95% CI: 1.37–9.47; P = 0.009) after adjustment for age, tumor size, tumor grade, lymph node metastasis, ER, PR, HER2, and adjuvant therapy (Table 3).