AIM: The treatment of non-small-cell lung cancer has changed after the 
development of the immune checkpoint inhibitors. Although the most studied 
biomarker is PD-L1 expression, its clinical significance is still debatable. In 
this article, we show the updated survival analysis of all published data.
METHODS: We searched in network and conference data sources for relevant 
clinical studies of immunotherapy for non-small-cell lung cancer that assessed 
the PD-L1 expression even as an exploratory analysis. The updated survival 
hazard ratios (HR) were included in the analysis.
RESULTS: 14 studies with 2857 patients were included (2019 treated with 
immunotherapy). The response rate was as higher among PD-L1-positive patients 
(RR: 2.19, 95% CI: 1.63-2.94). PD-L1 expression was also related to better 
progression-free survival (HR: 0.69, 95% CI: 0.57-0.85) and better overall 
survival (HR: 0.77, 95% CI: 0.67-0.89).
CONCLUSION: PD-L1 overexpression predicts activity as well as better survival 
for patients treated with immune checkpoint inhibitors.