Expression Of PD-L1 And CDK4 In Colorectal Adenocarcinoma And Its Clinical Pathological Significance

Objective To detect the expression of CDK4 and PD-L1 in colorectal cancer and analyze its relationship with clinicopathological characteristics.To observe the relationship between the expression of these two factors and the prognosis of patients,and to explore whether CDK4 and PD-L1 can be the prognostic factors for colorectal cancer patients.To analyze the correlation between the expression of CDK4 and PD-L1 in colorectal cancer.To provide a basis for the combined application of CDK4 inhibitors and PD-L1 inhibitors in colorectal cancer.Methods From 2016 to 2017,115 cases of colorectal cancer pathological tissue samples and clinical data were collected from the 940 th hospital of Joint Logistics Support force of Chinese People’s Liberation Army,and 40 cases were paracancerous tissue(the shortest distance from the edge of the cancer tissue>5cm).All of the included patients had primary pathological diagnosis of colorectal adenocarcinoma,and the relevant clinical and pathological data were complete.None of the included patients had any other serious diseases of cardiovascular,neurological,endocrine or other aspects,and none received radiotherapy,chemotherapy or other tumor-related treatment before surgery.The paraffin specimens of colorectal cancer patients that meet the standard were collected from the specimen library to make tissue chips,and CDK4 and PD-L1 immunohistochemical staining was performed on the tissue chips to check the expression of both in colorectal cancer.Statistical analysis of the relationship between the expression of PD-L1 and CDK4 and clinicopathological characteristics and whether there is a correlation between the two.Results1.There were 38 cases(33%)of PD-L1 positive expression in 115 colorectal cancer tissues.Compared with the paracancerous tissues,the positive rate was 0,and the difference was statistically significant(P<0.05).In addition,the site,differentiation degree and lymph node metastasis of cancer tissues of PD-L1 positive patients were compared with those of negative patients,and the differences were statistically significant(P<0.05).There was no significant correlation with the patient’s age,gender,tumor size,and microsatellite instability(P>0.05).By using Kaplan-Meier survival curve analysis to analyze the relationship between PD-L1 expression and prognosis in 95 patients who were followed up successfully,there were24 cases(64.9%)of PD-L1 positive patients with 3-year progression-free survival(PFS),Compared with 43 patients(74.1%)who were negative for 3 years without progression,the difference was statistically significant(P<0.05).2.There were 50 cases(43.5%)with positive CDK4 expression,and 3 cases(7.5%)with positive CDK4 expression in paracancer tissues,the difference was statistically significant(P<0.05).The difference in expression of CDK4 in colorectal cancer tissue was statistically significant with lymph node metastasis and pathological type(P<0.05),and had no significant relationship with the age,sex,tumor size,and degree of differentiation of patients(P>0.05).There were 28 cases(60.9%)of 3-year PFS in CDK4-positive patients,which was statistically significant compared with 39 cases(79.6%)of patients who were negative 3-year progression-free(P<0.05).3.The expression of PD-L1 and CDK4 was positively correlated(rs = 0.204,P<0.05).Conclusion1.The expression of PD-L1 may be related to the occurrence and development of colorectal cancer.The positive expression of PD-L1 in patients with colorectal cancer has a higher rate of lymph node metastasis than negative patients,a 3-year progression-free survival period is short,and the prognosis is poor.2.The expression of CDK4 may be related to the occurrence and development of colorectal cancer.CDK4-positive patients had a higher rate of lymph node metastasis than negative patients,a 3-year progression-free survival period was short,and poor prognosis.3.The expression of PD-L1 and CDK4 is positively correlated,suggesting that the combined application of PD-L1 inhibitor and CDK4 inhibitor may bring better clinical benefits to patients.