The Correlation Between PD-1/PD-L1 Expression And EGFR Mutation-Positive In NSCLC And Its Clinical Significance

Objective:To explore the correlation between PD-1/PD-L1 expression and EGFR mutation-positive in NSCLC(mainly lung adenocarcinoma)and its clinical significanceMethods:1.A total of 58 patients with EGFR mutation-positive NSCLC(advanced lung adenocarcinoma)who have then had received the EGFR-TKI therapy were collected,between January 2012 and January 2016 at the 1st Affiliated Hospital of KMU.2.EGFR mutation status in exons 18-21 were tested in the tumor samples obtained from biopsy or surgical resection,using the ARMS and the qPCR diagnostic kit.3.Immunohistochemistry(IHC)was performed to evaluate the expressions of PD-1,PD-L1,CD4+ and CD8+ TILs.4.ORR)and DCR were evaluated according to the RECIST 1.1.PFS and OS of these patients were calculated.5.Relationship between PD-L1 expression and various clinicopathologic parameters was analyzed using the χ2 test.The Kaplan-Meier method was used to estimate survival probability,and the log-rank test used to determine statistical significance.All tests were two-sided.P<0.05 was considered as statistically significant.Statistical analyses were done using a IBM SPSS Statistics software package(version 24.0).Results:1.In a cohort of 58 patients,the positive rate of PD-1 and PD-L1 in tumor specimens were 53.4%and 32.8%,respectively.2.Expression of neither PD-L1 nor PD-1 were correlated with multiple clinical/pathological characteristics ’of patients,including gender,age,smoking history,PS status when received EGFR-TKIs,chemotherapy history before the treatment,and metastases(P>0.05 for all cases).Nevertheless,there was a significant correlation between PD-1 and Ki-67 expression,for which Ki-67>14%had higher PD-1 expression,compared to Ki-67≤14%(P=0.005).3.No significant correlation between PD-L1 expression and CD4+ or CD8+ TIL scores was found in patients with EGFR-mutation-positive NSCLC(P>0.05 for each case).4.The DCR of patients with PD-L1-positive tumors was significantly higher than those whom with negative ones(93.5%,29/31 versus 59.3%,16/27;P=0.004),while no statistical significance observed for the difference in ORR(35.5%,11/31 versus 18.5%,5/27;P=0.079).5.PD-L1-positive patients expressed higher DCR(P =0.004)zafter the TKIs therapy,as well as longer PFS(P =0.001)and OS(P =0.004),but no significant correlation was observed between PD-1-positive patients and clinical outcomes.Conclusion:The EGFR-positive-NSCLC(advanced lung adenocarcinoma)patients are more suitable for the EGFR-TKIs treatment.It shows higher DCR,PFS,OS.PD-L1 might be a eligible biomarker candidate to predict the curative effect of EGFR-TKIs and prognosis of these NSCLC subtype patients...