The efficacy and safety of first‑line anti‑PD‑1/PD‑L1 immunotherapy for gastric esophageal cancer: A systematic review and meta‑analysis of phase III randomized controlled trials

Immunotherapy-based regiments have potential as first-line treatment for advanced gastric esophageal cancer. The present study aimed to conduct a meta-analysis of the association between the efficacy and safety of first-line immunotherapy combined with chemotherapy in patients with unresectable locally advanced or metastatic gastric esophageal cancer. Subgroup analysis of patients with programmed death ligand 1 (PD-L1) combined positive score (CPS) was conducted to identify the characteristics of patients with immune benefit and to provide a decision-making basis for clinical practice. PubMed, Embase, Cochrane Library and other databases were searched to collect randomized controlled trials of immunotreatment-based regimens (experimental group) versus conventional first-line chemotherapy regimens (control group) for unresectable locally advanced or metastatic gastric esophageal cancer. The main outcome measures included progression-free survival (PFS), overall survival (OS), objective response rate, disease control rate and safety, and the secondary outcomes were the differences in OS and PFS between patients with PD-L1 CPS ≥10 and those with PD-L1 CPS