Efficacy of PD-1/PD-L1 inhibitors in gastric or gastro-oesophageal junction cancer based on clinical characteristics: a meta-analysis

Abstract

Purpose: Programmed death-1 (PD-1) and its ligand (PD-L1) inhibitors have been reported in several clinical trials for gastric cancer and gastroesophageal junction cancer (GC/GEJC). We presently carried out a meta analysis to evaluate the potency of PD-1/PD-L1 inhibitors in advanced GC/GEJC individuals with different clinical features and to determine patients more probably benefiting from the treatment. Methods: Randomized clinical trials (RCTs) in databases that compared PD-1/PD-L1 inhibitors to chemotherapy in patients with GC/GEJC published before May 2022 were retrieved. Basic characteristics were extracted from the included studies as well as hazard ratios (HR) and 95 percent confidence intervals (CI) for all individuals and subgroups. The inverse variance weighting method was used to evaluate pooled treatment data. Findings: Four RCTs involving 2,253 individuals were included. The results suggested that PD-1/PD-L1 inhibitors substantially enhanced overall survival (OS) (HR, 0.91; CI 95%, 0.83–1.00; p = 0.04) but not progression free survival (PFS) (HR, 1.17; CI 95%, 0.83–1.64; p = 0.38) in GC/GEJC individuals compared with chemotherapy. Significantly improved OS was observed in individuals aged < 65 years (HR, 0.84; p = 0.003), and men (HR, 0.88; p = 0.02), but not in individuals aged ≥ 65 years (HR, 0.97; p = 0.62), and women (HR, 0.98; p = 0.82). Implications: PD-1/PD-L1 inhibitors improve OS but not PFS compared with chemotherapy in GC/GEJC. Age and sex could be used to predict the treatment potency of PD-1/PD-L1 inhibitors in GC/GEJC.