Efficacy of consolidation of immune checkpoint inhibitor after chemoradiation for unresectable, locally advanced PD‑L1 negative non‑small cell lung cancer: A systematic review and meta‑analysis.

Chemoradiotherapy (CRT) followed by consolidation of immune checkpoint inhibitors (ICIs), such as durvalumab or pembrolizumab, for patients with unresectable, locally advanced non-small cell lung cancer (NSCLC) with tumor PD-L1 expression <1% remains a topic of controversy. Previous studies from PubMed, Cochrane Library and Embase databases were searched for a meta-analysis. A total of 16 studies were included in part one of the meta-analysis and it was observed that consolidation of ICIs after CRT improved overall survival (OS) [hazard ratio (HR) 1.46; P=0.005] and progression-free survival (PFS) (HR 1.26; P=0.023) for the patients with PD-L1 expression ≥1% compared with those with PD-L1 expression <1%. Then, 15 studies were included in part two of the meta-analysis and the results indicated that the pooled 1, 2 and 3-year OS were 77% vs. 83% (P=0.07), 55% vs. 59% (P=0.327) and 38% vs. 51% (P=0.006) for CRT alone compared with CRT followed by consolidation of ICIs, respectively. The pooled 1, 2 and 3-year PFS were 51% vs. 53% (P=0.632), 29% vs. 40% (P=0.015) and 20% vs. 28% (P=0.153) for CRT alone compared with CRT followed by consolidation of ICIs, respectively. The findings of the present study highlighted that the benefits of CRT followed by consolidation of ICIs were higher compared with CRT alone in patients with unresectable, locally advanced NSCLC and PD-L1 expression <1%. Consolidation of ICIs after CRT would provide greater benefits for locally advanced NSCLC patients with PD-L1 expression ≥1% compared with those with PD-L1 expression <1%.