Vascular Endothelial Growth Factor (VEGF) Expression and Angiogenesis in Gastric Cancer

ABSTRACT

PURPOSE: This study was designed to evaluate the angiogenic activities of gastric cancer tissue and adjacent normal gastric tissue and to analyze the correlations between the clinicopatholoic factors of gastric cancer and tumor angiogenic activity. METHODS: Sets of both tumor tissue and adjacent normal gastric tissue were sampled from 49 patients with gastric cancer at the time of gastrectomy. Each specimen was evaluated for the expression of VEGF mRNA by reverse transcriptase polymerase chain reaction (RT-PCR). For the microvessel count of each tissue sample, immunohistochemical staining was done using antiCD31 antibody. As a control group, 10 paraffin blocks of normal gastric tissue from patients with benign disease were selected and stained with the same antibody in order to count the microvessels. RESULTS: The microvessel count of the tumor tissue was higher than that of normal tissue, with a mean+/-SD of 74.10+/-30.33 and 24.69+/-10.11, respectively (p<0.001). The microvessel count of the control group was 23.40+/-6.77 and was not significantly different from that of normal tissue samples taken from patients with gastic cancer. VEGF/beta actin ratios measured from the results of RT-PCR were 0.70+/-0.32 in tumor tissue and 0.51+/-0.26 in normal tissue (p<0.001). In each tissue sample, there was a significant correlation between the microvessel count and VEGF/beta actin ratio (p<0.01 in the tumor tissue, p<0.05 in normal tissue). Micro-vessel count of tumor tissue was related with sex and types of Lauren's classification (p<0.05, p<0.01, respectively). The VEGF/beta actin ratio of tumor tissue was related to sex and degree of vascular invasion of tumor cells (p<0.05). Other clinicopathologic factors, such as age, histologic type, TNM stage, tumor depth, lymph node metastasis, and perineural invasion, were not associated with the degree of microvessel count and the level of VEGF mRNA expression. CONCLUSION: Gastric cancer shows marked angiogenic activity and the angiogenesis is related to some clinicopathologic factors. These results suggest that the clinical application of antiangiogenic agents may have a role in the treatment of gastric cancer.