Research On PD-L1Expression And Significance In Patients With NSCLC

ObjectiveIn this modern era of medicine where the concept of personalized medicine is replacing population based medicine and conventional treatment modalities like chemotherapy are slowly being replaced by targeted therapies, we cannot ignore the impact of any study conducted in the field of cancer immunology and immunotherapy. Over the past few years PD-1-PD-L1pathway has received a considerable amount of interest from the researchers working in the field of cancer immunotherapy, as many studies done in this field identified it as an important immune-inhibitory pathway responsible for helping tumor to evade immune response. Expression of PD-L1, a ligand for PD-1has been described in many tumor types including NSCLC and considered as poor prognostic factor for survival. Clinical trials of drugs targeting this pathway are already on the run. Lung cancer is one of the major cause of mortality in many countries including china where every year130,000deaths occur because of it. However, very few researches have been done regarding the role of PD-L1in NSCLC and even among these the results of various studies are still conflicting. The main objective of this study was to examine the expression and significance of PD-L1in NSCLC patients.MethodsA retrospective analysis was conducted on209NSCLC patients who had undergone diagnostic surgery as well as treatment and follow up for NSCLC in TJMUCIH. Immunohistochemistry was utilized as a primary technique to examine the expression of PD-L1in FFPE tissue samples of NSCLC, collected from these patients during diagnostic/therapeutic surgery. Immunohistochemistry staining was analyzed to examine the difference in PD-L1expression among various clinicopathological variables as well as the prognostic significance and independent predictive value of PD-L1in NSCLC.ResultsSignificant difference in PD-L1expression was observed in between two histological subtypes (Adenocarcinoma and Squamous cell carcinoma) of NSCLC. PD-L1expression by NSCLC tumor tissue was found be a good prognostic marker in NSCLC patients with better overall survival in those with higher expression than those with negative or low PD-L1expression.PD-L1was also identified as an independent predictor of outcome in NSCLC patients.ConclusionPD-L1can be considered as an important and independent marker in predicting the outcome of NSCLC patients as well as their response to treatment. A powerful and reliable tool to measure its expression should be devised in future in an attempt to finding a cure for this otherwise resilient tumor which is responsible for high mortality and morbidity among modern human population.