A meta-analysis reveals prognostic role of programmed death ligand-1 in Asian patients with non-small cell lung cancer

Accumulating studies explored the clinicopathologic and prognostic value of programmed death ligand-1 (PD-L1) in non-small cell lung cancer (NSCLC), but the results were controversial. We therefore conducted a meta-analysis to evaluate the predictive role of PD-L1 in NSCLC patients. We systematically collected relevant studies from PubMed, Embase, Web of Science and China National Knowledge Infrastructure. The pooled hazard ratios (HRs) with 95% confidence intervals (CIs) for overall survival (OS), and odd ratios (ORs) with 95% CIs for clinicopathologic factors were calculated. A total of 15 studies involving 3605 patients were included in this meta-analysis. The results showed no prognostic role of PD-L1 in the whole patients (HR=1.60, 95% CI: 0.88-2.89, P=0.123). Subgroup analysis showed that PD-L1 was associated with decreased OS in Asian patients (HR=2.00, 95% CI: 1.55-2.57, P < 0.001). Among all the clinicopathologic factors, PD-L1 overexpression was significantly in relevance with poor tumor cell differentiation (HR=1.84, 95% CI: 1.49-2.28, P < 0.001), late stage (HR=1.21, 95% CI: 1.02-1.43, P=0.026) and anaplastic lymphoma kinase (ALK) translocation (HR=2.63, 95% CI: 1.08-6.40, P=0.034), but not with other factors. In conclusion, our meta-analysis demonstrated that PD-L1 has a prognostic role in Asian patients with NSCLC.