Clinical Study On Detection Of CTC And Expression Of E-cadherin And MMP-9 In Invasion And Metastasis Of Gastric Cancer

Objective We detected the count and phenotype of circulating tumor cells in the blood of patients with gastric cancer,as well as the expression of E-cadherin and MMP-9 protein in cancer tissues and adjacent tissues,and we compared with these and the clinicopathological data and lymph node metastasis of the patients with gastric cancer.We investigated the correlation between the changes in CTCs counts and phenotypes and the expression of E-cadherin and MMP-9 in the invasion and metastasis of gastric cancer.And we can provide clinical guidance for predicting the risk of recurrence and metastasis of gastric cancer.Methods Eighty-six patients who underwent radical gastrectomy for general surgery in The 940 th Hospital of Joint Logistics Force of People's Liberation Army from June 2017 to October 2018 were enrolled.Before the operation,we collected the fasting peripheral venous blood of patients in the morning,and enriched the CTCs by immunofluorescence and confirmed it by immunomagnetic microparticle-negative enrichment.After the operation,we collected the cancer tissues and adjacent tissues of the patients,and detected the expression of E-cadherin and MMP-9 protein by immunohistochemistry(SP).And we compared the relationship between these data and and clinicopathological data and lymph node metastasis in patients with gastric cancer.The chi-square test or Fisher exact probability method was used to compare the count data between two groups.The correlation analysis was performed by Logistic regression analysis.We defined P<0.05 as significant difference.Results 1.There are 86 patients with gastric cancer who were included in the study,and 78 were positive for CTCs,and the positive rate was 90.7%.Among them,7 patients had CTCs with both epithelial and interstitial(7/78,9%);68 patients had CTCs only interstitial type(68/78,87.2%);2 patients had mixed three phenotypes of CTCs phenotype(2/78,2.6%);1 patient showed only mixed CTCs(1/78,1.3%);The interstitial changes of CTCs were statistically different from tumor T stage(P=0.003),lymph node metastasis(P=0.012),TNM stage(P=0.040),and vascular invasion(P=0.003);2.E-cadherin expressed in gastric cancer cells membrane,the expression rate of cancer tissue was 48.84%(42/86),and the expression rate of adjacent tissues was 82.58%(71/86).The difference in expression between cancer tissue and adjacent tissues was statistically significant(P<0.05);and the difference in low expression of E-cadherin was statistically significant between the tumor size(P<0.001),T stage(P=0.002),vascular invasion(P=0.025)and CTCs(P=0.022)(P<0.05);3.MMP-9expressed in gastric cancer cells cytoplasmic,the expression rate of cancer tissue was 63.95%(55/86),and the expression rate of adjacent tissues was 7.91%(24/87).The difference in expression between cancer tissue and adjacent tissues was statistically significant(P<0.05);and the difference in high expression of MMP-9 was statistically significant the tumor T stage(P=0.009)and CTCs(P=0.016)(P<0.05).4.There was a correlation between low expression of E-cadherin and high expression of MMP-9 in Gastric cancer tissue(P<0.05),and it was negatively correlated(kappa value=-0.317);5.The lymph node metastasis were significantly correlated to tumor size(P=0.01),T stage(P<0.001),vascular invasion(P=0.008),CTCs(P=0.016),E-cadherin expression(P<0.001)and MMP-9 protein expression of gastric cancer(P<0.001);And the infiltration depth T3~T4(OR=0.017,CI=1.364~24.186)and MMP-9 positive expression(OR=0.038,CI=1.079~15.568)may be independent risk factors for lymph node metastasis(P<0.05).Conclusion 1.The mesenchymal transformation of CTCs in patients with gastric cancer promotes the invasion and metastasis of the tumor;2.There is a negative correlation betweenlow expression of E-cadherin and high expression of MMP-9 protein in gastric cancer patients,and both of them are related to tumor infiltration depth and positive CTCs,which may be involved in the invasion and metastasis of the tumor;3.The high invasive depth of T3~T4and the high expression of MMP-9 in gastric cancer patients are independent risk factors for lymph nodes metastasis,which can provide clinical guidance for predicting the risk of recurrence and metastasis of gastric cancer.