Effect of PD‐1/PD‐L1 immune checkpoint inhibitor in squamous and nonsquamous non‐small cell lung cancer: A systematic review and meta‐analysis

Abstract

BackgroundThe effects of programmed cell death protein 1/programmed cell death ligand 1 (PD‐1/PD‐L1) immune checkpoint inhibitors (ICIs) in patients with squamous and nonsquamous non‐small cell lung cancer (NSCLC) remain controversial. We conducted a meta‐analysis to summarize the existing evidence on this topic.MethodsWe searched PubMed, Medline, and Embase for studies published before December 1, 2022, comparing PD‐1/PD‐L1 ICIs with docetaxel in squamous and nonsquamous NSCLC patients in any language. The different hazard ratio (HR) values for overall survival (OS) and progression‐free survival (PFS) were calculated in this study.ResultsA total of seven studies were identified. In a summary analysis of all studies, the HR values of OS in patients with nonsquamous and squamous NSCLC were 0.73, 95% confidence interval (CI): 0.67–0.79 and 0.70, 95% CI: 0.62–0.79, respectively. In patients with PD‐L1 expression levels of 1% or higher, the HR values of OS in nonsquamous and squamous NSCLC patients were 0.60, 95% CI: 0.49–0.74 and 0.72, 95% CI: 0.54–0.96, respectively. The HR values of OS in nonsquamous and squamous NSCLC patients with PD‐L1 expression levels of 5% or higher were 0.46, 95% CI: 0.35–0.59 and 0.55, 95% CI: 0.39–0.79, respectively. In nonsquamous and squamous NSCLC patients with PD‐L1 expression levels of 10% or higher, the HR values of OS were 0.42, 95% CI: 0.32–0.54, and 0.53, 95% CI: 0.36–0.78, respectively.ConclusionThe meta‐analysis demonstrated possible evidence that there was different efficacy of PD‐1/PD‐L1 ICIs on OS in squamous and nonsquamous NSCLC patients with different PD‐L1 expression levels. Subgroup analysis showed that there was a greater OS benefit in patients with nonsquamous NSCLC.