Expression Of Mismatch Repair Protein In Colon Cancer And Its Clinical Significance

Objective:To investigate the expression and clinicopathological significance of mismatch repair proteins MLHI,MSH2,MSH6 and PMS2 in colon cancer.Methods:The expression level of MMR protein MLHI,MSH2,MSH6 and PMS2 in 314 colon cancer patients were detected by immunohistochemistry(IHC)in the pathology department of the First Hospital of Shanxi Medical University from January 2019 to December2020.SPSS24.0 software was used for statistical description and statistical analysis of the gender,age,location differentiation of the largest diameter of the tumor,histological type,TNM stage,lymph node metastasis,vascular cancer,thrombitic nerve invasion,MMR and related gene expression(MLH1,PMS2,MSH2,MSH6,MLH1,PMS2,MSH2,MSH6,MLH1,PMS2,and MSH2/MSH6)MLH1 PMS2 and the correlation between MSH2 and MSH6 USES Spearman correlation analysis The maximum diameter the mass position of different age and gender neoplasm differentiation degree Histology TNM staging vascular tumor emboli and nerve invasion of lymph node metastasis between MLH1 PMS2 MSH2 and MSH6 expression differences,and 2 or Fisher’s exact probability method is used to using Spearman correlation analysis and binary classification Logistic regression analysis to explore the MMR MLH1 PMS2 The influence factors of MSH2 and MSH6 gene expression were bilateral P<0.05 was considered statistically significant.Results:Among the 314 cases of colorectal cancer,colorectal cancer was predominantly male in 176cases(56.1%),> 60 years old in 206cases(65.6%),> 5cm206 in 65.6 cases(65.6%),tumor in the right colon in 108cases(34.4%),moderately differentiated in 256cases(81.5%),mucinous adenocarcinoma in 45 cases(14.3%),and adenocarcinoma without mucus in 269cases(85.7%).According to TNM staging,there were 212cases(67.5%)in stage Ⅰ-Ⅱ,209cases(66.6%)without lymph node metastasis,266cases(84.7%)with II suppository and 252cases(80.3%)without nerve invasion(see Table 2-1).The expressions of MLH1,PMS2,MSH2 and MSH6 mismatch repair gene proteins in colorectal cancer tissues were as follows: of the 314 colorectal cancer cases,50 were d MMR cases,with a deletion rate of 18.9%(50/314).The deletion rates of MLH1,PMS2,MSH2 and MSH6 are9.2%(29/ 314),10.8(34/314),3.2%(10/314)and 3.5(11/314),The deletion rates of MLH1/PMS2,MSH2/MSH6 and MLH1/PMS2/MSH2/MSH6 protein were 7.6%(24/314),2.5%(8/314)and 7.6%(24/314)respectively.Spearman-related results showed that there was a significant positive correlation between the expression of MLH1 and PMS2(rs=0.738,P < 0.001),and that of MSH2 and MSH6(rs=0.755,P < 0.001),indicating that MLH1 and PMS2,MSH2 and MSH6 often co-expression loss,mainly MLH1 and PMS2 combined deletion(see tables 2-3,tables2-4).The deletion rate of MLH1 expression was significantly different among sex,tumor size,tumor location,differentiation degree and mucus content,while the loss rate of PMS2 protein expression was significantly different between sex,tumor size,tumor location and mucus content(P < 0 05),and there were significant differences between sex,tumor size,tumor location,tumor location and mucus content(P < 0 05),and there were significant differences between sex,tumor size,tumor location and mucus content(P < 0 05).There was no significant difference in the deletion rate of MSH2 and MSH6 expression among sex,age,maximum tumor diameter,tumor location,degree of differentiation,histological type TNM stage,lymph node metastasis,vascular tumor thrombus and nerve invasion(P >0.05.The loss rate of);MMR protein expression was significantly different between male and female,mucus,tumor site and differentiation degree.Female is a risk factor for loss of MMR protein expression.The location of the tumor is the protective factor for the loss of MMR protein expression,and non-mucinous adenocarcinoma is the protective factor for the loss of MMR protein expression.(see Table 2-7).Conclusion:1、MLH1 and PMS2 combined deletion were the main mismatch repair proteins,and the negative expression of MLH1 was mostly seen in women with a 5cm mass with mucus and moderately differentiated right colorectal cancer patients.Negative expression of PMS2 was more common in women with right colorectal cancer with a mass of 5cm with mucus2、d MMR colorectal cancer is more common in women with mucus,low differentiation,right colorectal cancer.