Research Of The Relevance Between PD-L1 And E-cadherin Expressions And The Prognosis Of NSCLC

Objective:The purpose of this study is to investigate the expressions of PD-L1 and E-cadherin in patients with NSCLC who received surgery as well as the significance of those proteins as independent prognostic indicators.Materials and methods:A total of 55 patients with NSCLC who received radical surgery at Second Affiliate Hospital of Dalian Medical University from January 1,2009 to January 1,2015 were enrolled into the study.Collect the tumor tissues of all the patients and the tissues adjacent to tumor of 20 cases among the 55 cases.All the patients underwent radical surgery in Thoracic Surgery and were diagnosed as NSCLC by Department of Pathology,and then received ≥3 cycles of platinum-containing two-drug chemotherapy regularly 4-5 weeks after surgery.Regular review during chemotherapy.Estimate the expression of PD-L1 and E-cadherin in the samples by immunohistochemistry(SP),collect the clinical pathological data and follow up by telephone,then record the date of recurrence and metastasis and the date of death.The expression of PD-L1,E-cadherin,the clinical data and pathological features were analyzed using SPSS20.0 statistical software.The relationship between the clinical characteristics of the patients with the expression of PD-L1,E-cadherin was analyzed by chi square test;Spearman correlation analysis was used to analyze the correlation between PD-L1 expression and E-cadherin expression.The Kaplan-Meier method and Log-rank test were used to analyze the association of the expression of PD-L1 and E-cadherin,the clinical characteristics with the Disease-free survival(DFS)of the patients,and draw survival curves.COX regression model was used for multivariate analysis.Results:1.The positive expression rates of PD-L1 and the abnormal expression rates of E-cadherin in 55 cases of NSCLC tissues were 53%(29/55)and 51%(28/55);while in tissues adjacent to tumor,the positive expression rates of PD-L1 and the abnormal expression rates of E-cadherin were 20%(4/20)and 25%(5/20).The abnormal expression rate of PD-L1 and E-cadherin in NSCLC were higher than that in adjacent tissues,and the differences were statistically significant(P=0.012,P=0.046).2.The positive expression of PD-L1 was associated with clinical stage of the patients,lymph node metastasis status and the pathological type(P=0.02,P=0.045,P=0.024).The patients with later stages,lymph node metastasis and adenocarcinoma have a higher positive expression rate of PD-L1.There was no significant correlation between the positive expression rate of PD-L1 and gender,age,smoking history,degree of differentiation of the patients(P > 0.05).The abnormal expression of E-cadherin was associated with the differentiation degree of the tumor tissue(P=0.027),and the abnormal expression rate of E-cadherin in the patients with low differentiation degree was higher than that in those with high differentiation degree.There was no significant correlation between the abnormal expression rate of E-cadherin and gender,age,smoking history,lymph node metastasis status,clinical stage and pathological type of the patients(P > 0.05).3.The positive expression of PD-L1 was significantly correlated with the abnormal expression of E-cadherin in tumor tissues of patients with NSCLC(P=0.022,r=0.309).4.The DFS in patients with the positive expression of PD-L1 and the abnormal expression of E-cadherin was significantly shorter than that in normal group(P=0.014,P=0.017),suggesting that the positive expression of PD-L1 and the abnormal expression of E-cadherin may indicate a poor prognosis.Further,the DFS in patients with both positive expression of PD-L1 and the abnormal expression of E-cadherin in patients was significantly shorter than that of patients with both normal expression(P = 0.001).The patients NSCLC in earlier clinical stage and without lymph node metastasis have a better prognosis(P < 0.05);the degree of differentiation,smoking history,gender,age and pathological type were not significantly correlated with prognosis of the patients(P > 0.05).There was no significant correlation between the choice of chemotherapy and prognosis of the patients(P>0.05).Fuether analysis of the combination of the two expressions,COX regression model multivariate analysis showed that the expression level of E-cadherin and clinical stage were significantly associated with DFS(P=0.019,P=0.000),but there was no significant association between the expression of PD-L1,lymph node metastasis status and DFS(P > 0.05).Conclusion:In patients with NSCLC,late stage,lymph node metastasis,pathological type of adenocarcinoma patients,these factors contribute to the positive expression of PD-L1.The degree of differentiation is lower in patients with abnormal expression of E-cadherin.Positive expression of PD-L1 was positively correlated with abnormal expression of E-cadherin.The DFS of patients with positive expression of PD-L1 and the abnormal expression of E-cadherin was significantly reduced,indicating a poor prognosis.Therefore,the detection of the expression level of PD-L1 and E-cadherin plays an important role in the judgment of prognosis.In particular,the combined detection of the two is more significant.