Gastric cancer is the fifth most common cancer, yet research and prevention efforts remain limited. Lorna Rothery spoke with Dr Jin Young Park, the leader of the Gastric Cancer Prevention Team at the International Agency for Research on Cancer, about the necessary steps for improvement
Q. What progress has been made to aid the early detection of gastric cancer in recent years?
Recent progress in gastric cancer prevention has been limited globally. While high-income East Asian countries, such as Japan and Korea, have established nationwide screening programs, most countries lack organized efforts. Korea primarily uses upper endoscopy, while Japan traditionally relied on upper GI series but has also shifted towards endoscopy.
Other countries, such as those involved in the Health Flagship Project in Bhutan, have conducted one-time screening interventions focused on gastric cancer, but they lack ongoing national programs. Taiwan also promotes screening largely through the treatment of Helicobacter pylori infections, yet many regions do not prioritize gastric cancer prevention and early detection.
While evidence from clinical trials supporting the effect of upper endoscopy in reducing mortality is insufficient, there is moderate evidence coming from Japan and Korea’s observational studies showing a mortality reduction. While Korea has biennial screenings, these consume a significant portion of the National Cancer Screening Program budget. The focus is shifting towards primary prevention, particularly through the eradication of H. pylori, which has been shown to significantly reduce gastric cancer incidence and mortality.
A key question remains how best to integrate primary prevention with existing secondary prevention strategies to maximise their effectiveness. Initiatives like Korea’s HELPER study aiming to evaluate the long-term impact of treating H. pylori in the general population on the incidence of gastric cancer will provide much needed information.
Q. What is the current state of research on gastric cancer prevention, and how important are coordinated international research efforts in this field?
Gastric cancer is the fifth most common cancer and cause of cancer death worldwide, but funding and research interest on prevention of this deadly disease from various agencies have been limited. While the incidence of gastric cancer has decreased, we still see nearly a million new cases each year, making it one of the top five cancer types.
In our latest article in Nature Medicine, we challenge the notion that gastric cancer will disappear on its own and also the terms such as African Enigma. This belief has historically hindered research funding on prevention; research has concentrated mainly on translational or therapeutic strategies, neglecting H. pylori-related gastric cancer that is the majority, despite evidence that prevention interventions are effective.
The unequal distribution of funding has led to minimal research efforts, making it challenging to translate research findings on preventive strategies into effective policy. Many methodologies that work for prevention of other cancers can also be applied to gastric cancer, potentially saving countless lives. We’ve established a global network of researchers dedicated to advancing gastric cancer prevention, emphasizing the need for more funding and additional epidemiological and implementation studies on prevention to inform policy.
The Gastric Cancer Prevention Team at IARC focuses on several key global efforts, including assessing the current and future burden of gastric cancer and conducting etiological research. The team’s research efforts encompass etiological studies, focusing on identifying biomarkers related to exposure and risk factors, such as salt intake, and exploring metabolic biomarkers tied to gastric cancer. The team’s research also generates clinical trial evidence on specific interventions, including H. pylori screen-and-treatment.
Our long-term clinical trial, HELPER, conducted in collaboration with the National Cancer Center in Korea, is assessing whether H. pylori eradication can reduce the risk of gastric cancer in the general asymptomatic adult population. The trial is scheduled for an interim analysis in 2026. This trial is one of the largest addressing this issue.
IARC is also collaborating with the University of Latvia to conduct the GISTAR study, the largest European research project on gastric cancer prevention. Securing funding has been challenging due to limited awareness. However, with the European Commission’s recommendations to consider, including gastric cancer in screening programs, we are seeing renewed interest. We aim to determine effective preventive strategies to reduce gastric cancer mortality in Europe.
Additionally, we are engaged in broader European projects and have held discussions on implementing population-based H. pylori screening and treatment programs, leveraging evidence from trials in Eastern Asia. Despite recommendations from the Working Group convened by IARC over a decade ago, progress has been slow due to a lack of guidance, highlighting the need for effective implementation strategies. We have published a new IARC Working Group Report, a comprehensive 444-page document available online, to provide guidance and outline essential components for implementation of H. pylori screen-and-treat strategies at the population level as an effective prevention program.
Q. What do you anticipate regarding the future burden of gastric cancer?
Despite a decrease in the incidence rate of gastric cancer in many countries, that has long been considered an ‘unplanned triumph’, our projection published in Nature Medicine suggests that the future global burden of gastric cancer will significantly increase without active control efforts. Among girls and boys born between 2008 and 2017, an estimated 15.6 million lifetime gastric cancer cases are projected and about 76% of these cases are linked to H. pylori infection, making them largely preventable. Even regions with currently low gastric cancer rates may face a sharp increase due to shifting demographics, i.e., aging and growing population. The largest increases are expected in low-incidence, low-Human Development Index (HDI) areas, particularly in sub-Saharan Africa, underscoring the urgent need for greater global investment in gastric cancer prevention. These increases will still be anticipated, even under the extreme assumption of a 3% decrease in gastric cancer incidence uniformly across countries over 20 years.
It’s important not to overlook how public health programs and interventions can effectively reach those populations in need. For instance, while gastric cancer isn’t a significant issue in many Western European countries or in the United States based on the current overall incidence rates which may be low, there are still high-risk populations such as specific ethnic groups or migrant populations coming from high-risk areas in these low incidence regions.
Our study highlighted the fact that gastric cancer will remain a major public health problem globally over the next decades, with the substantial demographic-driven increase in burden, especially in these traditionally low-risk areas, compounding the continuing high burden in high-risk areas. Our results endorse the importance of making changes to the current practice and urge regional health systems to be prepared to manage the growing burden of this largely preventable disease by planning pilot and feasibility projects, including H. pylori screen-and- treat programs. The perception that these cancers are not significant problems appears to stem from decreasing trends in overall incidence rates, which may have resulted in the lack of sustainable investment and coordinated action. If gastric cancer were given more attention, we could potentially improve funding and research efforts on gastric cancer prevention and implementation of prevention strategies from public health authorities. Focus should be given on the large number of people at risk especially those who are infected with H. pylori as a primary factor contributing to gastric cancer, as there are effective means to address these issues. We urgently need increased investment and political will to translate recommendations into action, particularly for those who will benefit the most from such prevention programmes. Understanding the primary causes of the disease and generating real-world evidence of prevention strategies is essential for improving outco
