MKI67 and metastatic malignant neoplasm in the lymph nodes: After PSM, the 3-year DFS rate was analyzed by subgroups according to the menopause status (premenopausal or postmenopausal), tumor size (T1 or T2), lymph node metastasis (N0, N1, N2 or N3), clinical stage (II or IIIA), ER (positive or negative), PR (positive or negative), HER-2 (positive or negative), Ki-67 expression (< 20% or ≥ 20%), and histological grade (grade II or III).