MKI67 and metastatic malignant neoplasm in the lymph nodes: The metformin group showed smaller tumors (1.78 ± 0.87 cm vs. 2.21 ± 1.28 cm; p = 0.049), fewer cases of high Ki-67 expression (>15%) (35.6% vs. 62.3%; p = 0.004), and no lymph node metastasis (0% vs. 15.3%; p = 0.022).