Methods and Epidemiologic Definitions
This review synthesizes gastric cancer (ICD-10 C16) epidemiology over 2016–2026, focusing on adenocarcinoma subtypes stratified by anatomic location (cardia versus non-cardia) and Lauren histologic classification (intestinal, diffuse, mixed). Epidemiologic measures include age-standardized incidence rates (ASIR) and mortality rates (ASMR) per 100,000 person-years using the World Standard Population, 5-year prevalence, case fatality, and disability-adjusted life years (DALYs) decomposed into years of life lost (YLL) and years lived with disability (YLD). Temporal trends are expressed as average annual percent change (AAPC) or estimated annual percentage change (EAPC). Data sources prioritized include IARC GLOBOCAN 20221, Global Burden of Disease (GBD) 20193132, WHO Mortality Database2, and national cancer registries from Japan, Korea, China, the United States (SEER/NAACCR), and EU member states213.
Current Global and Regional Burden
According to GLOBOCAN 2022, gastric cancer ranks fifth globally in incidence with approximately 1.08 million new cases annually1. Asia bears the largest absolute burden, accounting for 49.2% of global cancer incidence and 56.1% of cancer mortality1. GBD 2019 data document 1.3 million incident cases and 957,185 deaths globally in 2019, with East Asia contributing 626,489 cases (48% of global total)32. The global ASIR was 15.6 per 100,000 in 2019, having declined from 22.4 per 100,000 in 1990 (EAPC approximately −1.5% per year)3132.
Regional heterogeneity is pronounced. In 2019, East Asia recorded the highest ASIR at 30.2 per 100,000, followed by high-income Asia-Pacific (28.2 per 100,000) and Andean Latin America (22.4 per 100,000), while high-income North America had the lowest at 6.1 per 100,00032. Country-level data reveal Mongolia with the highest ASIR at 43.7 per 100,000, followed by Bolivia (34.0) and China (30.6), whereas Malawi recorded the lowest at 3.3 per 100,00032. Among the 36 countries analyzed for mortality trends (2015–2019), men in the Russian Federation (ASMR 17.09 per 100,000), Chile (16.90), and Belarus (15.75) had the highest rates, while the United States (2.34), Sweden (2.92), and Australia (3.03) had the lowest2. Sex-stratified analyses consistently show male-to-female incidence ratios of approximately 2:1 to 3:1 globally, with a Norwegian population-based study (2001–2011) reporting a ratio of 1.72 and ASIRs of 8.0 per 100,000 for males and 3.6 per 100,000 for females13.
Temporal Trends (2016–2026 YTD)
Age-standardized mortality rates have declined in nearly all high-income countries with quality mortality data over the past three decades. The Republic of Korea demonstrated the steepest decline from 1990–2019, with an AAPC of −5.2% for both sexes2. The EU-27 as a whole showed an AAPC of −3.3%2. Projections for 2025 forecast continued declines: Korea (−53% to −54% reduction versus 2015–2019 baseline), Japan (−32% for men, −37% for women), and EU-27 (−24% for men, −28% for women)2. In China, ASIR declined from 37.56 per 100,000 in 1990 to 30.64 in 2019, while ASMR decreased from 37.73 to 21.72 per 100,00031.
Critically, favorable overall trends mask emerging disparities. Gastric cancer incidence among young adults (under 50 years) has been increasing in the United States, Canada, Brazil, Mexico, and the United Kingdom, contrasting with sustained declines in older age groups5. Exceptions to declining mortality also include predicted increases for females aged 35–64 in France (+20.3%) and the United States (+7.3%), and males aged 35–64 in Canada (+2.7%), though these cohorts have low baseline rates2.
Anatomic and Histologic Subtype Distribution
The proportion of cardia versus non-cardia gastric cancer exhibits marked geographic variation. In low-incidence, low-mortality countries (Canada, United States, Australia), cardia cancers represent approximately 40% of male cases and >20% of female cases, whereas high-mortality countries like Argentina and Korea show cardia proportions of only approximately 6% in men and 3.5–4.8% in women2. Among European men, cardia proportions ranged from 10.3% (Belarus) to 62.0% (Denmark)2. A Norwegian study documented an increase in cardia cancer proportion among males from 29.7% to 39.1% over 2001–2011 (p=0.005)13. Non-cardia gastric cancer, strongly associated with Helicobacter pylori infection, remains responsible for more cases overall globally, with ratios between 2:1 and 3:1 relative to cardia cancer in most countries2.
Lauren diffuse-type gastric cancer is significantly more frequent among patients below 60 years, females, and in non-cardia locations13. Five-year overall survival is significantly better for Lauren intestinal-type (log-rank p=0.003)13. Microsatellite instability-high (MSI-H) status, identified in 23.5% of gastric cancers, is significantly associated with non-cardia location, intestinal type, and improved prognosis (5-year survival 67.6% versus 35% for microsatellite-stable tumors, p<0.001)610.
Demographic Stratifications and Disparities
Gastric cancer incidence increases sharply with age, with median age at diagnosis of 76.2 years in a Norwegian cohort13. However, age-specific trends diverge: while older-age cohorts show sustained declines, young-onset gastric cancer (under 50 years) is rising in multiple regions5. Sex disparities are universal, with male predominance across all regions; among the Norwegian cohort, the male-to-female ratio was 1.7213. Race and ethnicity substantially modify risk within countries; the increasing incidence in young Hispanic men in the United States has been particularly documented57. Rural–urban gradients and socioeconomic disparities reflect differential access to screening and H. pylori eradication programs, particularly in China31.
Stage at diagnosis varies markedly by region and screening infrastructure. In Norway (a non-screening country), early gastric cancers comprised only 8.3% of cases, whereas 44% presented with metastatic disease13. Conversely, screening programs in Japan and South Korea detect a higher proportion of early-stage disease, contributing to lower mortality despite high incidence2.
Risk Factor Stratifications and Population-Attributable Fractions
Helicobacter pylori infection is the dominant modifiable risk factor for non-cardia gastric cancer. In China, H. pylori prevalence averaged 42.06% (2009–2013), with a pooled relative risk for gastric cancer of 1.89 (95% CI: 1.57–2.26), yielding a population-attributable fraction (PAF) of 37.38% for non-cardia gastric cancer (approximately 105,536 cases in 2012)20. In Korea, H. pylori was associated with a summary odds ratio of 1.81 (95% CI: 1.29–2.54) overall, with the highest risk for cardia gastric cancer and early gastric cancer (SOR=2.88 for both)21. Eradication therapy reduces gastric cancer incidence by approximately 47–54%, with a pooled incidence rate ratio of 0.53 (95% CI: 0.44–0.64)2223.
Epstein-Barr virus (EBV) infection, identified in approximately 10% of gastric cancers globally, confers a 10-fold increased risk overall (SOR=10.0; 95% CI: 5.89–17.29), with the highest risk in Far East Asia (SOR=14.28; 95% CI: 6.58–30.98)24. Coinfection with H. pylori and EBV may synergistically increase risk and lower age at diagnosis25.
Globally, GBD 2019 attributes 17.2% of gastric cancer DALYs to smoking and 7.8% to high dietary sodium32. Among males, 24.0% of DALYs were attributable to smoking versus 4.3% in females32. Obesity, metabolic syndrome, and gastroesophageal reflux disease (GERD) are associated with increasing cardia gastric cancer in Western populations, though quantified PAFs for these factors were not identified in the retrieved literature3. Hereditary gastric cancer syndromes (CDH1 mutations in hereditary diffuse gastric cancer, Lynch syndrome) account for approximately 1–3% of cases; in a Dutch Lynch syndrome cohort, 20% were infected with H. pylori, comparable to the general population28.
Mortality, DALYs, and Quality-of-Life Impact
Global gastric cancer deaths totaled 957,185 in 2019, with an ASMR of 11.9 per 100,000, declined from 20.5 per 100,000 in 199032. China, India, and Japan collectively accounted for 58.6% of global deaths32. The global age-standardized DALY rate declined from 493.4 per 100,000 (1990) to 290.6 per 100,000 (2019)32. Mongolia recorded the highest ASMR at 40.04 per 100,000, while the United States had the lowest at 3.40 per 100,00031.
Five-year overall survival varies widely by region and stage. In Norway, overall 5-year survival was 16%, with 40.9% for patients undergoing R0/R1 resection13. China demonstrated a mortality-to-incidence ratio of 0.845, indicating higher case fatality than most developed countries31. Among metastatic patients, median survival is 3 months, with worst outcomes for those with bone and liver metastases (2 months)11.
The DALY burden is dominated by YLL, though the proportion of YLL versus YLD for gastric cancer specifically was not explicitly quantified in the retrieved sources34. Health-related quality-of-life decrements include dumping syndrome, nutritional deficiencies (vitamin B12, iron, calcium), and weight loss following gastrectomy, contributing to YLDs throughout survivorship, though quantified impacts were not reported in the available literature.
Prevention and Screening Context
Primary prevention through H. pylori test-and-treat strategies has demonstrated effectiveness, particularly in high-prevalence populations2930. Economic analyses suggest eradication is cost-effective in high-risk populations, and targeting CagA-positive strains optimizes benefit30. Organized endoscopic screening programs in Japan and South Korea have contributed to stage shift and mortality reductions, as evidenced by Korea's −5.2% annual mortality decline2. Pilot programs in China are underway, though comprehensive participation rates, stage-shift data, and cost-effectiveness analyses for these programs were not identified in the retrieved materials. Equity considerations include rural–urban access gaps and disparities in program uptake, particularly in China31.
Limitations and Data Quality Considerations
Registry coverage varies substantially, with underreporting probable in low-resource settings. Coding heterogeneity at the cardia/esophagogastric junction and evolving H. pylori prevalence complicate trend interpretation. Ecological inference linking risk-factor trends to incidence changes should be undertaken cautiously. The retrieved evidence primarily covers high- and middle-income countries with established cancer registries, limiting generalizability to sub-Saharan Africa and parts of South Asia.
Conclusion
Gastric cancer remains the fifth most common cancer globally, with declining age-standardized incidence and mortality in most regions driven by H. pylori control and screening in high-burden countries. Persistent high burden in East Asia, emerging increases in young adults in Western countries, and the distinct epidemiology of cardia versus non-cardia subtypes underscore the need for tailored prevention strategies. Clinicians should recognize demographic risk stratifications and support evidence-based H. pylori eradication and screening programs where appropriate. Public health priorities include expanding access to early detection in high-incidence regions, addressing rising incidence in young populations, and implementing primary prevention through infection control and dietary modification.