ERBB2 and breast cancer: The factors considered in this study include lymphovascular invasion (odds ratio = 7.108, HER2 negativity (odd ratio = 2.997), low Ki-67 expression (odd ratio = 4.231), suspected positive axillary lymph nodes before surgery (odd ratio = 5.113), histological grade III (odd ratio = 5.109), and breast-conserving surgery breast cancer stage (odd ratio = 5.025) (all with p < 0.05) (Table 3).