Gastric cancer is a major global health threat and is the third-leading cause of cancer deaths worldwide, as the disease causes more than 720,000 deaths per year globally. Gastric cancer detection during a symptomatic stage often results in poor survival and frequent recurrence despite the availability of various modalities that can be used as rescue treatments. As the size of the elderly population is continuously increasing, the International Agency for Research on Cancer has estimated that the current high incidence rate of gastric cancer will remain stable or even increase by 2030 without the development of effective measures for preventing the disease. Helicobacter pylori is the most important etiologic factor for gastric cancer. It is estimated that 89% of non-cardiac gastric cancers, which account for 78% of gastric cancer cases, are attributable to H. pylori infection. Since H. pylori can be eradicated with a short-course of antibiotic treatment, identifying and eradicating H. pylori infection may represent an effective strategy for reducing the risk of gastric cancer. However, in real-life settings, the magnitude of the benefit of H. pylori eradication with respect to the risk of subsequent gastric cancer development remains unclear. To address this important question, researchers from the Department of Internal Medicine and the Institute of Epidemiology and Preventive Medicine of National Taiwan University and Baylor College of Medicine in Houston, Texas, USA, have conducted a systematic review and meta-analysis of randomized trials and cohort studies involving both asymptomatic H. pylori carriers (i.e., primary prevention) and individuals undergoing endoscopic resection of early gastric cancer (i.e., tertiary prevention) to investigate the association between H. pylori eradication and gastric cancer incidence. The study was published in the May 2016 issue of Gastroenterology. From a total of 8,061 articles, 24 eligible studies (from China, Colombia, Finland, Japan, Korea, and Taiwan) including a total of 48,064 individuals/340,255 person-years and 715 incident gastric cancers were included in the analysis. Gastric cancer developed in 253 of 20,484 infected individuals who received eradication therapy compared with 462 of 27,580 infected individuals who did not receive anti-H pylori treatment; thus, eradication therapy yielded a risk reduction of 46% (95% confidence interval: 35% to 54%), and no significant heterogeneity was noted between studies. The benefits of H. pylori eradication did not differ according to study design, sex, or follow-up period. The baseline gastric cancer incidence in each study varied widely from 34.3 to 10,256.4 cases per 100,000 person-years. Researchers also identified a non-linear correlation between baseline gastric cancer incidence and the incidence rate ratio. The upper 95% CI of the incidence rate ratio for eradication decreased to below 1 when the baseline gastric cancer incidence exceeded 150 cases per 100,000 person-years, and the incidence rate ratio continued to decrease concurrently with increasing baseline incidence up to approximately 1,200 cases per 100,000 person-years and then stabilized. These findings indicate that studies on high-risk individuals have superior statistical power and that studies involving low-to-intermediate risk groups have been constrained by insufficient sample sizes and short follow-up periods. In conclusion, “by synthesizing available evidence from multiple populations and clinical scenarios, our study shows that H. pylori eradication reduces gastric cancer risk in all risk groups,” the authors wrote in an interview with Reuters. The purpose of H. pylori eradication is to resolve gastric inflammation, halt gastric mucosal damage progression, prevent further H. pylori-induced DNA damage, improve gastric acid secretion, and restore the microbiome to normal. This study provides strong clinical support for the use of a mass eradication program to reduce the enormous disease burden of gastric cancer globally. Reference Yi-Chia Lee, Tsung-Hsien Chiang, Chu-Kuang Chou, Yu-Kang Tu, Wei-Chih Liao, Ming-Shiang Wu, David Y Graham. Gastroenterology. 2016 May;150(5):1113-1124.e5. doi: 10.1053/j.gastro.2016.01.028. Clinical Professor Yi-Chia Lee Department of Internal Medicine yichialee@ntu.edu.tw Professor Ming-Shiang Wu Department of Internal Medicine mingshiang@ntu.edu.tw Reference Yi-Chia Lee, Tsung-Hsien Chiang, Chu-Kuang Chou, Yu-Kang Tu, Wei-Chih Liao, Ming-Shiang Wu, David Y Graham. (2016) Association Between Helicobacter pylori Eradication and Gastric Cancer Incidence: A Systematic Review and Meta-analysis. Gastroenterology, 150(5), 1113-1124.e5. DOI: 10.1053/j.gastro.2016.01.028. Clinical Professor Yi-Chia Lee Department of Internal Medicine yichialee@ntu.edu.tw Professor Ming-Shiang Wu Department of Internal Medicine mingshiang@ntu.edu.tw