Relationship Between Peritumoral Lymphatic Vessel Density And Pathobiological Behaviour Of Gastric Cancer

IntroductionLymphatic metastasis is the major pathway in metastasis of gastric carcinoma to distant organs and is the important influential factor for the prognosis. Lymphangiogenesis has recently been considered important for lymphatic metastasis of malignant tumors. Over the past several years, the reliable marker for lymphatics have been identified, which provide the requirement to study effectiveness of lympgatic vessel in oncobiology. In this study, the antibody to VEGFR-3 was used to determine lymphatic vessel density(LVD) in gastric carcinomas(GC) and gastric benign tissue(GBT). The findings were analyzed in combination with patient age, sex, tumor size, tumor stage, differentiation, growth pattern, depth invasion, lymph node metastasis, pN, rNand other clinicopathological parameters to find the method to to direct clinical and judge the prognosis.Materials and MethodsMaterial1. Samples: All sample used were obtained from paraffin-embedded tissues of the surgical speciments of patients admitted to the 1st Affiliated Hospital of China Medical University during 2005-2006.2. Reagents: Rabbit Anti-FLT4, SABC kit, DAB developer, 0.01mmolPBS, 3%H₂O₂, microtome, microscope.Methods1. staining: Rabbit anti-FLT4 were examined immunohistochemical SABC body staining method in 118 cases of human gastric cancer. The dilute strength of FLT4 antibody was 1:150.2. result assessment: Identification of lymphatics in gastric carcinoma: prominently large, irregular morphology, thin-walled lymphatics with FLT4 positivity were detected mainly at the periphery of the tumor. The lymphatic vessels were distinguished from adjacent blood vessels. The former were positive for FLT4, which is thought to be a reliable marker for lymphatic vessels. The latter were surrounded by smooth muscle or contained red blood cells. Evaluation of lymph vessel density (LVD): Any endothelial cell highlighted by FLT4 reactivity and clearly separated from connective tissue elements was regarded as a countable vessel. LVD is assessed on the basis of Wendner.Statistical analysisStatistical analysis was performed using the t-test and analysis of variance(SNK-q), P<0.05 was considered statistically significant.ResultTwenty cases of non-cancerous gastric tissues from gastric benign lesion were used to reflect LVD of normal tissues. In the 20 cases, median LVD was 5.39±0.92 vessels/HP×400. The difference of LVD between gastric benign lesion and gastric cancer was significant(P = 0.000). The difference of LVD between early and advanced gastric carcinoma was significant(P = 0.000). P-LVD was significantly correlated with tumor size, depth invasion, lymph node metastasis, pN, rN and tumor stage in gastric carcinoma(P<0.05) . No significant correlation was found between P-LVD or patient age, patient sex, differentiation, growth pattern(P>0.05).Conclusion1. P-LVD of carcinoma tissue in early gastric carcinoma was similar with LVD of benign gastric tissue.2. P-LVD of carcinoma tissue in early gastric carcinoma was significantly lower than in advanced gastric carcinoma of gastric tissue.3. P-LVD was significantly associated with pathobiological behaviour and lymphatic metastas of gastric cancer.4. P-LVD was significantly associated with pN, rN.