AUTHOR=Cai Huarong , Zhang Haimei , Jiang Yuequan 

TITLE=Prognostic and Clinicopathological Value of Programmed Cell Death Ligand1 Expression in Patients With Small Cell Lung Cancer: A Meta-Analysis

JOURNAL=Frontiers in Oncology

VOLUME=10

YEAR=2020

URL=https://www.frontiersin.org/journals/oncology/articles/10.3389/fonc.2020.01079

DOI=10.3389/fonc.2020.01079

ISSN=2234-943X

ABSTRACT=<p><bold>Background:</bold> Programmed death-ligand 1 (PD-L1) is an immune checkpoint molecule expressed by cancer cells. Previous studies have demonstrated the prognostic role of PD-L1 expression in patients with small cell lung cancer (SCLC), where the results were inconsistent. Therefore, we conducted a meta-analysis to identify the prognostic impact of PD-L1 on SCLC.</p><p><bold>Methods:</bold> We searched the PubMed, Embase, ISI Web of Science, and Cochrane Library databases for articles published before and on March 2nd, 2020. Data of PD-L1 expression in tumor cells detected using immunohistochemistry methods were extracted for analysis. Pooled hazard ratios (HRs) with confidence intervals (CIs) and odds ratios (ORs) with 95% CIs were calculated to assess the correlations among PD-L1, overall survival (OS), and clinicopathological factors.</p><p><bold>Results:</bold> Nine studies of 921 patients published between 2015 and 2019 were included in this meta-analysis. The pooled data (HR = 0.91, 95% CI = 0.46–1.80, <italic>p</italic> = 0.787) indicated that PD-L1 expression is not a significant predictor of poor OS. Moreover, the results also revealed that PD-L1 expression is not significantly associated with gender (OR = 1.12, 95% CI = 0.73–1.74, <italic>p</italic> = 0.601), age (OR = 1.15, 95% CI = 0.58–2.30, <italic>p</italic> = 0.683), pN stage (OR = 0.65, 95% CI = 0.24–1.72, <italic>p</italic> = 0.381), pT stage (OR = 1.16, 95% CI = 0.26–5.23, <italic>p</italic> = 0.847), serum lactate dehydrogenase level (OR = 1.06, 95% CI = 0.13–8.43, <italic>p</italic> = 0.958), or performance status (OR = 0.69, 95% CI = 0.24–1.95, <italic>p</italic> = 0.479). No significant publication bias was detected in this meta-analysis.</p><p><bold>Conclusions:</bold> This meta-analysis suggests that PD-L1 expression is not a significant prognostic factor of poor survival in SCLC. Because of significant variations, high-quality studies are needed to validate our results.</p>