Correlations of TNM staging and lymph node metastasis of gastric cancer with MRI features and VEGF expression.

OBJECTIVE: To investigate the correlations of expression of vascular endothelial growth factor (VEGF) in gastric cancer tissues of patients and magnetic resonance imaging (MRI) features with clinical tumor-node-metastasis (TNM) staging and lymph node metastasis, and to analyze the diagnostic value of MRI features for preoperative TNM staging and lymph node metastasis of patients with gastric cancer, and the roles of VEGF in tumor development and metastasis.

METHODS: A total of 120 gastric cancer patients treated in our hospital from May 2015 to July 2017 were selected as objects of study. The VEGF protein expressions in gastric cancer tissues of patients with different TNM staging and lymph node metastasis degrees were detected using immunohistochemical method, and the correlations of VEGF protein expression with TNM staging and lymph node metastasis were analyzed. Before operation, MRI was used to predict TNM staging and lymph node metastasis of all patients, and prediction results were compared with postoperative pathological diagnosis results. At the same time, the differences in lymph node apparent diffusion coefficient (ADC), long diameter and short diameter, relative ADC of primary lesion (rADCp) and relative ADC of muscle (rADCm) were compared and analyzed between lymph node metastasis group and non-lymph node metastasis group.

RESULTS: The VEGF expression in patients with stage-N3 gastric cancer was about 7 times that in patients with stage-N0 gastric cancer, and it was increased with the increased degree of lymph node metastasis (p< 0.01). The VEGF expression in patients with distant metastasis of tumor cells was significantly higher than that in patients without distant metastasis (p< 0.01). The expression of VEGF in stage-T4 gastric cancer was about 10 times that in stage-Tis cancer, and the larger the infiltration depth of tumor cells was, the higher the expression level of VEGF would be (p< 0.01). The VEGF expression in gastric cancer tissues was positively correlated with the infiltration depth, lymph node metastasis and distant metastasis of tumor cells. Moreover, the prediction results of MRI for TNM staging and lymph node metastasis before operation were compared with postoperative pathological results, and it was found that there was better consistency (Kappa = 0.739). ADC, rADCp and rADCm in gastric cancer patients without lymph node metastasis were significantly higher than those in patients with lymph node metastasis, but the short diameter and long diameter were obviously shorter than those in patients with lymph node metastasis, and the differences were statistically significant (p< 0.05).

CONCLUSION: The VEGF protein expression in gastric cancer tissues is positively correlated with TNM staging and lymph node metastasis in patients. The preoperative prediction results of MRI are well consistent with postoperative pathological results, and MRI features are correlated with lymph node metastasis in patients, which has an important guiding significance for the diagnosis and treatment of gastric cancer.