Prevention and screening of gastric cancer by helicobacter pylori management: Synthesis of existing data

Gastric cancer (GC) remains a significant global health challenge, ranking fifth in incidence and third in mortality worldwide. In 2020 alone, there were over a million new cases and nearly 770,000 deaths attributed to GC. The burden is particularly heavy in China, which accounts for nearly 44% of global cases, a statistic partly driven by the high prevalence of Helicobacter pylori (H. pylori) infection. Identifying and managing H. pylori infection, the most significant controllable risk factor for GC, has thus become a crucial focus in gastroenterology. Understanding and implementing strategies to manage H. pylori infection could significantly impact global health by reducing the incidence and mortality associated with GC.

Rationale of H. pylori Eradication for GC Prevention

The relationship between H. pylori and GC was first highlighted by Barry J. Marshall and J. Robin Warren in 1983. H. pylori initiates a cascade of gastric changes, progressing from chronic gastritis to atrophy, metaplasia, dysplasia, and eventually adenocarcinoma, known as the Correa cascade. This understanding underscores the importance of targeting H. pylori to prevent GC. Research into this relationship has focused on three main areas: the correlation between H. pylori infection and GC, the potential of H. pylori eradication to prevent GC, and the feasibility of population-wide H. pylori eradication as a preventive strategy. The evidence strongly supports the hypothesis that H. pylori eradication can significantly reduce the risk of GC.

Does H. pylori Infection Lead to GC?

Extensive studies from the 1980s to the 2000s have established a clear link between H. pylori infection and GC. For example, a study in 1998 showed that 37% of Mongolian gerbils inoculated with H. pylori developed GC. Epidemiological studies have further confirmed this link, demonstrating that H. pylori infection increases GC risk by 3.6 times. Today, it is recognized that up to 89% of noncardia gastric cancers are attributable to chronic H. pylori infection, while H. pylori-negative GC remains rare, accounting for only 0.4-2.3% of cases. These findings have been supported by various cohort studies, case-control studies, and meta-analyses, reinforcing the strong epidemiological and biological evidence linking H. pylori infection to the development of GC.

Can H. pylori Eradication Counteract Precancerous Lesions and Block GC Development?

In the 21st century, the focus has shifted to the effectiveness of H. pylori eradication in preventing GC. High-quality randomized controlled trials (RCTs) conducted in China and Korea have provided robust evidence that eradicating H. pylori can halt the progression of precancerous lesions. For instance, a trial in China involving 435 H. pylori-infected farmers showed that treatment significantly protected against the progression of premalignant lesions over ten years. Another community-based study in Taiwan demonstrated a 77.2% effectiveness in reversing gastric atrophy following mass H. pylori eradication.

Moreover, long-term follow-up studies have revealed significant regression in intestinal metaplasia (IM), a precancerous condition. The extended follow-up of a mass eradication program on Matsu Island showed a decrease in early and advanced-stage IM prevalence from 31.7% to 21.4% and from 11.8% to 1.8%, respectively. Meta-analyses have consistently shown that H. pylori eradication significantly reduces GC incidence, with relative risks ranging from 0.46 to 0.66 for primary and metachronous cancer. These findings underscore the therapeutic potential of H. pylori eradication not only in preventing GC but also in reversing precancerous conditions that could otherwise progress to malignancy.

Cost and Effectiveness of H. pylori Eradication as a Preventive Strategy

The feasibility of population-wide H. pylori eradication is supported by several high-quality meta-analyses. These studies demonstrate that H. pylori eradication not only lowers GC incidence but also reduces disease-specific mortality. However, the success of such programs varies by region, influenced by factors like ethnicity and strain types of H. pylori. For instance, regions with high H. pylori prevalence, such as certain African and Asian countries, might benefit more from screening programs compared to areas with lower prevalence rates.

Cost-effectiveness analyses have indicated that H. pylori eradication is a cost-effective strategy for GC prevention, especially in high-risk populations. The reduction in healthcare costs associated with treating advanced GC, along with improved patient outcomes and quality of life, supports the economic viability of widespread H. pylori eradication programs. Such programs should be tailored to the specific epidemiological and socioeconomic contexts of the target populations to maximize their effectiveness and sustainability.

Conclusions

H. pylori management has emerged as a pivotal strategy in the prevention and control of GC. The accumulated evidence supports the benefits of eradicating H. pylori to prevent the progression of precancerous lesions and reduce GC incidence. Future research and policy-making should focus on the feasibility and implementation of population-based H. pylori screening and eradication programs, particularly in high-risk regions. By leveraging these insights, the global burden of GC can be significantly alleviated. The integration of H. pylori eradication into broader public health initiatives could play a critical role in reducing the incidence of GC and improving global health outcomes.

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https://www.xiahepublishing.com/2835-3315/CSP-2023-00010

The study was recently published in the Cancer Screening and Prevention.

Cancer Screening and Prevention (CSP) publishes high-quality research and review articles related to cancer screening and prevention. It aims to provide a platform for studies that develop innovative and creative strategies and precise models for screening, early detection, and prevention of various cancers. Studies on the integration of precision cancer prevention multiomics where cancer screening, early detection and prevention regimens can precisely reflect the risk of cancer from dissected genomic and environmental parameters are particularly welcome.

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