Global lifetime estimates of expected and preventable gastric cancers across 185 countries

Abstract

Chronic infection with Helicobacter pylori is a modifiable cause of gastric cancer. To assist policymakers in advocating for and planning prevention strategies, we projected the future burden of gastric cancer, including that attributable to H. pylori, among a cohort of young people born in 2008-2017. Expected gastric cancer cases, in the absence of intervention, were quantified in 185 countries by combining national age-specific incidence rates from GLOBOCAN 2022 and cohort-specific mortality rates from the United Nations' demographic projections. Globally, 15.6 million (95% uncertainty interval 14.0-17.3 million) lifetime gastric cancer cases are expected within these birth cohorts, 76% of which are attributable to H. pylori. Two-thirds of cases will be concentrated in Asia, followed by the Americas and Africa. Whereas 58% of cases are expected in traditionally high-incidence areas for gastric cancer, 42% of cases are expected to occur in lower-incidence areas owing to demographic changes, particularly in sub-Saharan Africa, where the future burden could be six times greater than estimated in 2022. A shift in focus toward the life course of today's young people and their prospects of developing gastric cancer, with or without effective interventions, underscores the need for greater investment in gastric cancer prevention, including the implementation of population-based H. pylori screen-and-treat strategies.

Fig. 1. Country-specific estimates of gastric cancer cases.

Expected numbers of country-specific gastric cancer cases in individuals born between 2008 and 2017 in the absence of changes in the current control measures for gastric cancer and the cases attributable to H. pylori infection. a–c, Countries are grouped according to their contribution to the overall gastric cancer burden, with countries sorted according to the expected number of gastric cancer cases and subsequently grouped into the following five categories: >1,000,000 (group A; a), 100,000–1,000,000 (group B; b) and 35,000–100,000 (group C; c). Countries from groups D and E are included in Extended Data Fig. 1, with the corresponding number of gastric cancer cases provided in Extended Data Table 3.

Fig. 2. Ratio of the future-to-current number of gastric cancer cases.

Ratio of the average number of expected lifetime gastric cancer cases in an average single birth cohort across birth cohorts born between 2008 and 2017 versus the total number of cases estimated cross-sectionally in 2022 (indicated here as the ratio of change). The designations used and the presentation of the material in this article do not imply the expression of any opinion whatsoever on the part of WHO and the IARC about the legal status of any country, territory, city or area, or of its authorities, or concerning the delimitation of its frontiers or boundaries.

Fig. 3. Age-specific number of expected gastric cancer cases.

Age-specific distribution of the average number of expected gastric cancer cases in an average single birth cohort across birth cohorts of individuals born between 2008 and 2017 in the absence of changes in the current control measures, compared with those estimated cross-sectionally in 2022. ‘Ratio’ indicates the ratio of change.

Fig. 4. Correlation between the ratio of change and country-specific HDI.

The y axis is log₂ transformed. The black line and the gray shaded area represent the mean and the 95% confidence interval for the prediction of the fitted linear model.

Fig. 5. Global analysis outcomes by various tested parameters.

This figure shows the variation in the overall lifetime expected number of gastric cancer cases in individuals born between 2008 and 2017 according to changes in the model parameters. The variation could be read in terms of the absolute number of cases (top x axis) or the ratio of the lifetime expected number of gastric cancer cases (bottom x axis). The reference model parameters are the same as the ones assumed in the main text (that is, no competitive risk between CGC and NCGC, median UN death rate scenario, no annual percentage change (APC) for CGC and NCGC, no changes in the current public health intervention (PHI) for gastric cancer control). Each line on the y axis represents the specific parameter changed compared to the reference while all the other parameters remain unchanged. The tested parameters are as follows: (1) competing rate: including the CGC competing rate in the NCGC burden calculation and vice versa 2 (yes). (2) Death rate: changing the overall cause of death competing risk for the UN lower (lwr) or upper (upr) scenario. (3) APC CGC (10 years): applying APCs of −3%, −2%, −1%, 1%, 2% and 3% for 10 years to the CGC incidence rate. (4) APC CGC (20 years): applying APCs of −3%, −2%, −1%, 1%, 2% and 3% for 20 years to the CGC incidence rate. (5) APC NCGC (10 years): applying APCs of −3%, −2%, −1%, 1%, 2% and 3% for 10 years to the NCGC incidence rate. (6) APC NCGC (20 years): applying APCs of −3%, −2%, −1%, 1%, 2% and 3% for 20 years to the NCGC incidence rate. (7) PHI impact: applying the population-level impact of H. pylori screen-and-treat strategies by 80–100%.

Extended Data Fig. 1. Country-specific number of gastric cancer cases expected in persons born between 2008 and 2017 in the absence of changes in the current control measures for gastric cancer (dark grey bar) and the cases attributable to H. pylori infection (light grey bar).

Countries are grouped according to their contribution to the overall gastric cancer burden, with countries sorted according to the expected number of gastric cancer cases and subsequently grouped into the following categories: 10,000 to 35,000 (group D) and less than 10,000 (group E).

Extended Data Fig. 2. Global analysis outcomes by various tested parameters by region and sex*.

*This figure shows variation of the overall lifetime expected number of gastric cancers born between 2008 and 2017 according to changes of the model parameters. The variation could be read in terms of absolute number of cases (upper x-axis) or ratio of the lifetime expected number of gastric cancers (lower x-axis). The reference model parameters are the same as the ones assumed in the main text (that is no competitive risk between cardia (CGC) and non-cardia (NCGC) gastric cancer, median UN death rate scenario, no annual percentage change (APC) for CGC and NCGC, no changes in the current public health intervention (PHI) for gastric cancer control). Each line on the y-axis represents the specific parameter changed compared to the reference while all the other parameters remain unchanged. The tested parameters are: 1. Competing Rate: Including CGC competing rate in the NCGC burden calculation and vice and versa 2 (yes). 2. Death Rate: Changing the overall cause of death competing risk for UN lower (lwr) or upper (upr) scenario. 3. APC CGC (10 years): Applying −3%, −2%, −1%, 1%, 2% and 3% APC for 10 years to the CGC incidence rate. 4. APC CGC (20 years): Applying −3%, −2%, −1%, 1%, 2% and 3% APC for 20 years to the CGC incidence rate. 5. APC NCGC (10 years): Applying −3%, −2%, −1%, 1%, 2% and 3% APC for 10 years to the NCGC incidence rate. 6. APC NCGC (20 years): Applying −3%, −2%, −1%, 1%, 2% and 3% APC for 20 years to the NCGC incidence rate. 7. PHI Impact: Applying population-level impact of H. pylori screen-and-treat strategies by 80–100%.