Relationship Between PD-L1 Expression And EGFR,ALK In Non-small Cell Lung Cancer And Its Clinical Significance

Objective:1.To study the expression of programmed death ligand-1(PD-L1),epidermal growth factor receptor(EGFR)gene mutation,and anaplastic lymphoma in non-small cell lung cancer.Immunohistochemical staining was used to detect anaplastic lymphoma kinase(ALK),and to explore the correlation between PD-L1 and the latter two.2.To study and analyze the relationship between the expression of PD-L1 and clinicopathological features and prognosis,and to provide preliminary basis for the clinical treatment of non-small cell lung cancer targeted therapy and immune checkpoints.Methods: Collecting 967 specimens of non-small cell lung cancer(NSCLC)specimens from January 2017 to December 2017 in the Department of Pathology,Fourth Hospital of Hebei Medical University,including 727 adenocarcinomas,190 squamous cell carcinomas,31 adenosquamous carcinomas,and neuroendocrinology.There were 9 cases of cancer and 9 cases of other types of cancer.After fixed by 10% formalin,routinely drawn,paraffin embedded films,HE staining,light microscopy.The protein expression of PD-L1 and ALK was detected by immunohistochemistry VENTANA rabbit monoclonal antibody and the detection of non-small cell lung cancer by allele-specific amplification fluorescence polymerase chain reaction(PCR).EGFR mutations and mutation types.SPSS 22.0 statistical software was used to analyze the relationship between PD-L1 and EGFR,ALK and clinicopathological features.Results:1.The expression rate of PD-L1 in non-small cell lung cancer was 20.7%(200/967).PD-L1 expression was higher in the male group,tumor maximaldiameter> 2.5 cm group,T3 stage group,nerve invasion group,smoking history,and lymph node metastasis group than in the female group.Patients with tumor maximal diameter ?2.5 cm group,T1-2 stage group,no nerve invasion group,no smoking history group,no lymph node metastasis group(P<0.05).Univariate analysis showed that there was no correlation between PD-L1 expression and patient age,airway dissemination,clinical stage,and vascular tumor thrombosis.2.The expression of PD-L1 in non-small cell lung cancer was positively correlated with EGFR mutation(P<0.05).The positive rate of PD-L1 in patients with EGFR mutations was 27%,which was higher than that of those without mutations(19%).The difference was statistically significant(P<0.05).The correlation between PD-L1 expression and EGFR mutations was analyzed.The results showed that the expression of both were positively correlated in non-small cell lung cancer(P<0.05),but there was no significant correlation with the type of EGFR mutation(P>0.05).The expression rate of PD-L1 in ALK gene fusion cases was 1.5%,and the expression rate of PD-L1 in ALK gene fusion negative cases was 21%.The correlation between ALK gene fusion and PD-L1 expression was not statistically significant(P>0.05).4.EGFR mutation status,ALK,clinicopathological features and PD-L1 positive expression cases were included in Logistic regression multivariate analysis,showing that EGFR mutation status and lymph node metastasis were risk factors affecting the expression of PD-L1 in non-small cell lung cancer(P< 0.05),the difference was statistically significant.5.Follow-up data showed that the 1-year survival rate of 967 NSCLC patients was 98.86%,and the 1-year survival rate of PD-L1 expression was97.44%.The expression of PD-L1 was evaluated by Kaplan-Meier and Log Rank(P>0.05).The difference was not statistically significant.Conclusion:1.The expression of PD-L1 is related to gender,tumor maximal diameter,T stage,nerve invasion,lymph node metastasis and smoking history.2.In non-small cell lung cancer,PD-L1 is expressed in both EGFR and wild type mutants,but the mutation is higher than that in the wild type and there is a positive correlation.3.The expression of PD-L1 in non-small cell lung cancer is affected by the EGFR mutation status and lymph node metastasis.The use of PD-L1 as a checkpoint for immunotherapy,combined with EGFR mutation targeting drugs,may provide new methods for the treatment of these patients.