Nearly four decades have passed since the landmark assessment of gastric cancer epidemiology that declared its decline “an unplanned triumph.”1 In the USA, favorable trends for gastric cancer overall continued into the 21st century, partially offset by rising incidence of cardia subsite tumors2 and worrisome increases among White young adults.3 Notwithstanding, substantial disparities persist to this day among racial and ethnic subpopulations4 as well as among localities.5
In the current issue, Kendrick et al. characterize gastric cancer disparities along both of these important dimensions simultaneously. They used small area estimation models to analyze mortality trends by U.S. county, separately for White, Black, Asian, American Indian/Alaska Native, and Latino populations. Their observations and the supporting tables, maps and graphs are packed with information needed to understand and redress the underlying inequities. These county-level mortality data and models also invite further analyses for age-specific differences. Of particular interest is possible local variation in the gastric cancer incidence trends among White young adults, which have not been fully explained. Local mortality patterns or relationships may provide helpful clues.
This work warrants extension by the authors and other researchers to explore associations with local variations in disparities. Gastric cancer mortality rates should be correlated with county-level data for gastric cancer risk factors, either race-ethnic group-specific, as available, or otherwise overall. Some straightforward examples from US census data include population density, small area income and poverty estimates, small area health insurance estimates, fractions of immigrants by country-of-birth, measures of educational attainment and prevalence of household crowding. Creative use of other data sources may also incorporate information such as local availability of cancer and general health care and accessibility of nutritious food. Observed associations could suggest potential targets for remediation.
An important limitation of mortality data is that deaths from cancers of the gastric cardia and noncardia subsites are indistinguishable and thus combined. These cancers have different etiologies that would require different remedies. Inferences from mortality analyses must be thoughtfully integrated with other knowledge for appropriate interpretation and application.
As the authors noted, the burden of gastric cancer may be amenable to interventions that either prevent cancer occurrence (e.g., Helicobacter pylori eradication therapy) or detect it an early stage (e.g., upper gastrointestinal endoscopy screening). Promising prevention and early detection results have been reported from population-based programs in Japan, Korea and China, countries where gastric cancer incidence is higher than in the USA. The refined identification of high-risk populations in specific locations may facilitate evaluation for targeted implementation of similar approaches in the USA and potentially elsewhere in the Americas. Gastric cancer is a persistent health disparity that demands planning and informed action. This report by Kendrick et al. will help lead the way.
Contributors
C.S.R. conceptualised and wrote the article.
Declaration of interests
I declare no competing interests.
Acknowledgements
Funding source: This research was supported by the Intramural Research Program of the National Cancer Institute at the National Institutes of Health.
References
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