Clinical Exploration Into Immunotherapy Based On The PD-L1 Expression In Non-Small Cell Lung Cancer

PurposeTo explore the clinical and pathological factors influencing the expression of tumoral PD-L1 in non-small cell lung cancer patients,and to verify the prognostic value of PD-L1 in patients receiving immunotherapy or not.MethodsPatients who underwent PD-L1 expression test in Peking Union Medical College Hospital from Jun.2019 to May.2021 were taken into account.We also retrospectively included patients receiving immunotherapy in PUMCH from Jan.2016 to Sept.2020 whose pathological specimen were available for PD-L1 test.Paraffin embedded samples were cut into sections of 4-5μm and stained via immunohistochemical method with the aid of PD-L1 IHC 22C3 pharmDx.All patients included in survival analyses were followed-up at the out-patient department or through telephone call by May.2021 and overall survival(OS)as well as progress free survival(PFS)were calculated.Statistical analysis were conducted with SPSS 25.0 and a P value of>0.05 was considered significant.Results322 advanced non-small cell lung cancer were included,among which 133 had squamous cell carcinoma while 189 had non-squamous cell carcinoma.Altogether 164 patients(50.9%)had a TPS of over 1%compared to 158 lower than 1%.Males who were smoking or had smoked before at the time of diagnosis had significantly higher TPS(P=0.010 for the gender category and 0.042 for the smoking category).Higher TPS were also observed in non-squamous patients without driver mutation compared to those with a mutation(P=0.045).Patients receiving immunotherapy had a better OS compared to those never receiving immunotherapy(P=0.003)regardless of PD-L1 expression and driver gene mutation.Immunotherapy(RR=0.547,P=0.001)and wild-type driver gene(RR=0.614,P=0.037)proved to be independent protective factors for NSCLC patients in terms of overall survival while age over 65 years(RR=1.477,P=0.024)and stage IV(RR=1.814,P=0.007)served as risk factors.Among patients receiving immunotherapy,those whose TPS ≥1%had longer OS and significantly longer PFS(P=0.018)compared to those whose TPS<1%.Situation was the same for patients receiving first-ling therapy while the expression of PD-L1 did not correlate with the survival of patients receiving subsequent therapy.PD-L1 expression(RR=0.5 84,P=0.019)was the only factor influencing the PFS of patients receiving immunotherapy.ConclusionThe PD-L1 expression elevates in smokers and non-squamous cell carcinoma patients with wild type driver gene.Each subgroup of NSCLC patients benefits from immunotherapy and PD-L1 expression serves as a prognostic factor in patients receiving first-line immunotherapy.