More than one in five colorectal cancer (CRC) cases globally could be related to exposure to Helicobacter pylori, with China having the largest absolute number of CRC cases potentially linked to the bacterium, an international collaborative study led by investigators from the University of Hong Kong (HKU) has found.
The pooled risk-attribution model study estimated global and regional H. pylori exposure and its epidemiological association with CRC using data from systematic reviews and meta-analyses, stratified by region, diagnostic method and eradication status, among others. CRC estimates were derived from the Global Cancer Observatory (GLOBOCAN) 2022. [eGastroenterol 2026;4:e100436]
Based on 43 international studies involving 48.7 million individuals globally, exposure to H. pylori was associated with a 1.59-fold increased risk of CRC (95 percent confidence interval [CI], 1.36–1.87), consistent across most subgroups.
In limited observational studies, H. pylori eradication was associated with a reduced risk of CRC, but only after 10 years of follow-up.
Globally, under the pooled risk-attribution model based on estimates from all 43 included studies, an estimated 22.0 percent (95 percent uncertainty interval [UI], 14.7–29.4 percent) of CRC cases were potentially related to H. pylori exposure. Corresponding estimates were lower when restricted to population-based and cohort studies (n=14).
The Western Pacific Region had the highest related burden (estimated related proportion [ERP], 25.1percent; 95 percent UI, 16.4–34.1 percent). Mongolia had the highest ERP (36.1 percent; 95 percent UI, 23.3– 47.5 percent). In terms of absolute case count, China had the highest number of CRC cases potentially linked to H. pylori exposure (139,619; 95 percent UI, 87,908–186,158). “This finding may reflect multiple factors, including high background prevalence of H. pylori infection [such as China, Mongolia and Vietnam], limited population-wide eradication programmes, as well as rising CRC incidence due to rapid urbanization, dietary shifts and ageing demographics,” noted the researchers.
By contrast, despite similarly high H. pylori prevalence levels in the African, Southeast Asian and Eastern Mediterranean regions, the related CRC burden was comparatively lower. Across countries, higher H. pylori–related burdens were observed in settings with lower CRC incidence, and burden increased nonlinearly with rising H. pylori prevalence. Exploratory pseudo-cohort patterns suggested higher ERPs in later-born cohorts, while absolute case counts remained relatively stable.
“Unlike many inherited cancer risks, H. pylori infection is both detectable and treatable,” noted Professor Wai-Keung Leung of the Department of Medicine, HKU, a leader of the study. “Our study suggests that H. pylori may contribute substantially to the global burden of CRC. Understanding this relationship could help inform future CRC prevention strategies and identify new opportunities to reduce the associated risks worldwide.”
“Many countries and regions have already introduced population-based H. pylori screening and eradication programmes to reduce gastric cancer risk,” Leung continued. “The findings suggest that these programmes could potentially generate a dual cancer-prevention benefit by reducing the risks of both gastric cancer and CRC, particularly in areas where H. pylori infection remains highly prevalent and healthcare resources are limited.”
“Our goal is to provide evidence that informs public health and research priorities and to guide infection-targeted prevention strategies at both global and regional levels, complementing and extending beyond H. pylori eradication efforts to reduce the risk of multiple cancers,” concluded Leung.