MMP9 and Lymphatic Metastasis: Positive expression of VEGF and MMP-9 was correlated with lymphatic metastasis, and their positive expression rates were significantly higher in patients with lymphatic metastasis than those without it (VEGF: χ2 = 30.00; P = 0.001; MMP-9: χ2 = 18.27, P = 0.001).