Table 5.

Association with Helicobacter pylori infection and gastric cancer

	Prevalence of H. pylori	Diagnostic tool of H. pylori	Study design	P value
Helicobacter and Cancer Collaborative Group[68]	Non-cardia GC: OR: 5.9; 95%CI: 3.4-10.3	Serology and/or histology	Meta-analysis	P = 0.002
Huang et al[66]	For cagA-positive OR: 1.64; 95%CI: 1.21-2.241	Serology and/or histology	Meta-analysis	NA
Gastric cancer incidence decreased after H. pylori eradication
Lee et al[70]	Incidence rate ratio = 0.53; 95%CI: 0.44-0.64	Serology and/or histology; rapid urease test	Meta-analysis	NA
Chiang et al[71]	Reducing GC incidence of 0.53; 95%CI :0.3-0.69	Rapid urease test	Prospective study	P < 0.001

¹In Helicobacter pylori-infected populations, cagA-positive strains further increased the risk for gastric cancer by 1.64-fold. GC: Gastric cancer; OR: Odds ratio; CI: Confidence interval; H. pylori: Helicobacter pylori; NA: Not available.