| Background and ObjectiveGastric cancer is one of the most common malignant tumor in human, which stands the second place of incidence of cancer in men, stands the fourth place in women around the world. The incidence of gastric cancer is the third largest in china. Although the standard tumor resection, radical lymph node dissection of gastric cancer, and supplemented by postoperative chemotherapy have increased the five-year survival rate of patients than Simple gastrectomy, the prognosis of gastric cancer is still unsatisfactory.VEGF-C (vascular endothlial growth factor C) is the first growth factor which was found to induce lymphangiogenesis. To study the expression of VEGF-C in gastric carcinoma tissues and its impact on the lymphangiogenesis and lymph node metastasis, adopt appropriate methods to prevent tumor lymphangiogenesis and lymphatic metastasis, is very important to reduce the probability of gastric cancer metastasis and its recurrence.Materials and MethodsSamples:Tissue specimens used for this study were obtained from 60 cases of fresh primary gastric cancers tissues and their adjacent tissues. which were resected by the Second Affiliated Hospital of Zhengzhou University and Henan Province People's Hospital from October 2008 to June 2009.The cases were 39 males and 21 females, with a mean age of 54.3 years, All patients haven't received chemotherapy before operation. The size of primary tumor were estimated from tumor maximum diameter.2cases of tumor's diameter≤2 cm,49 cases between 2 cm and 5 cm, and the number whose tumor's diameter greater than 5 cm was 9.The degree of tumor differentiation, specific depth of invasion and the number of lymph node metastasised were judged by the pathology reports. Assessment of clinical pathology were referred to Japanese classification of gastric carcinoma tissues 2nd English edition. Distinguished by the pathological, there were 4 cases of well differentiated gastric cancer,17 cases of moderately differentiated gastric cancer,34 cases of poorly differentiated adenocarcinoma, and signet ring cell carcinoma in 5 cases. There were 2 cases in T1,20 cases in T2,29 cases in T3, and 9 cases in T4. After tumor resection of the whole primary tumor, two piece of the the fresh primary gastric cancers tissue and their adjacent tissues which were at least 5cm away from the gastric cancers were immediately cut. Grinded one pice of gastric cancers tissue in liquid nitrogen (-160℃) to prepare for RT-PCR, the ungrinded tissuses were embeded in paraffin. Made of 4μm thick sections prepared for immunohistochemical staining.Methods:The expression of VEGF-C mRNA in 60 pairs of fresh primary gastric cancers and their adjacent gastric tissues were determined by semi-quantitative reverse transcriptase-polymerase chain reaction (RT-PCR), the expression of VEGF-C protein and lymphatic vessel density was detected by immunohistochemistry.Statistical analysis:The date was analyzed by statistical software SPSS 11.5. t test,χ2 test,Fisher test and one-way ANOVA were used to analyze the difference and relationship between different groups.α=0.05 for the difference in the standard test of significance. Results1. The percentage of positive for VEGF-C mRNA was 63.33%(38/60), the percentage was 26.67%(16/60) in the adjacent gastric tissues, and gastric cancer tissuses have a higher expression than the adjacent gastric tissues(P=0.000).2. The expression rates of VEGF-C protein in gastric carcinoma tissues was 51.67% (31/60), The number was 18.33%(11/60) in the adjacent gastric tissues. There was a significantly difference between gastric carcinoma tissues and adjacent gastric tissues (P=0.000).3. The expression rates of VEGF-C protein was closely related with the expression of VEGF-C mRNA in gastric carcinoma tissues.4. The LVD in gastric carcinoma tissues (37.97±3.68) was significance higher than in the adjacent gastric tissues (12.66±1.31), the difference was significance. (P=0.000)5. The LVD in the marginal zone of gastric carcinoma tissues was 39.57±7.28, was 21.53±3.12 in the center of gastric carcinoma tissues, the difference was significance. (P=0.000)6. The LVD in the marginal zone of gastric carcinoma tissues was closely related with lymph node metastasis (P=0.000) and distant metastasis (P=0.000), but there was no significant correlation with the age at surgery, gender, tumor size, tumor location, Lauren classification, the depth of invasion, and TNM stage (P>0.05)7. The high percentage of positives for VEGF-C mRNA and its protein is closely related with LVD increased.Conclusions1. The expression of VEGF-C mRNA and VEGF-C protein are higher in gastric cancer tissues than in the adjacent gastric tissue.2. There are a large number of lymphangiogenesis in gastric cancer tissues, expecially in the marginal zone.3. VEGF-C highly expression in gastric cancer tissues is closely related with lymph node metastasis.
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