Relationship between Helicobacter pylori infection and programmed death-ligand 1 in gastric cancer: A meta-analysis

Figure 1 Diagram of database search and study inclusion. GC: Gastric cancer; HP: Helicobacter pylori; PD-L1: Programmed death ligand-1.

Figure 2 Forest plots for meta-analyses regarding the association between Helicobacter pylori infection and programmed death ligand-1 tumor expression in patients with gastric cancer. HP: Helicobacter pylori; CI: Confidence interval; OR: Odds ratio.

Figure 3 Sensitivity analyses. CI: Confidence interval; OR: Odds ratio.

Figure 4 Subgroup analyses. HP: Helicobacter pylori; PD-L1: Programmed death ligand-1; CPS: Combined positive score; IHC: Immunohistochemistry; NA: Not applicable; NOS: Newcastle-Ottawa scale.

Figure 5 Funnel plot showing a low risk of publication bias. Egger’s regression test also indicated a low risk of publication bias. A: Egger’s test; B: Funnel plots for the publication bias underlying the meta-analysis.