Prognostic value of programmed cell death-ligand 1 expression in patients with non-small-cell lung cancer: evidence from an updated meta-analysis

Abstract

Anyuan Zhong,1,* Yufei Xing,1,* Xue Pan,1,* Minhua Shi,1 Huajun Xu2 1Department of Respiratory Diseases, the Second Affiliated Hospital of Soochow University, Suzhou, 2Department of Otolaryngology, Shanghai Jiao Tong University Affiliated Sixth People’s Hospital, Otolaryngology Institute of Shanghai Jiao Tong University, Shanghai, People’s Republic of China *These authors contributed equally to this work Background: The association between the expression of programmed cell death-ligand 1 (PD-L1) and survival in patients with non-small-cell lung cancer (NSCLC) is controversial. Thus, we conducted a meta-analysis of all available studies to evaluate the prognostic role of PD-L1 expression in NSCLC.Materials and methods: PubMed, Embase, and Chinese (China National Knowledge Infrastructure and Wanfang) databases were searched to identify all eligible studies evaluating PD-L1 expression and the survival of NSCLC patients. Hazard ratios (HRs) and 95% confidence interval (CI) used to assess overall survival were extracted and pooled. Subgroup, sensitivity, and publication-bias analyses were also performed.Results: Eleven articles reporting 12 studies that included a total of 1,653 patients met the inclusion criteria and were included in the meta-analysis. Higher PD-L1 expression did not correlate with prognosis in terms of overall survival in patients with NSCLC (HR =1.21, 95% CI: 0.85–1.71, P=0.29). However, a subgroup analysis showed a significant association between PD-L1 expression and poor prognosis in Chinese patients with NSCLC (HR =1.55, 95% CI: 1.04–2.29, P=0.03). The sensitivity analysis showed that the pooled results were not affected by the removal of any single study. There was also no significant publication bias.Conclusion: Our meta-analysis indicated no statistically significant difference between PD-L1 expression and prognosis for patients with NSCLC. Additional, high-quality studies with larger sample sizes are needed to determine the prognostic value of PD-L1 expression in NSCLC. Keywords: non-small-cell lung cancer, programmed cell death-ligand 1, prognosis, meta-analysis