Changes in Geographic Variation and Socioeconomic Inequalities in Esophageal Cancer Mortality in China, 1973-2017

Geographic variability in esophageal cancer has been reported in China, but data are lacking at the local level. We aimed to investigate changes in disparities in esophageal cancer-related mortality among Chinese counties and whether county-level socioeconomic status was associated with this variation. We used data from a nationwide survey and population-based cancer registries to calculate esophageal cancer-related mortality rates for 782 Chinese counties for the periods of 1973-1975 and 2015-2017. We performed hotspot analysis to identify spatial clusters. We used a multivariable negative binomial regression model to estimate the associations between county-level socioeconomic factors and mortality. From 1973-1975 to 2015-2017, the age-standardized esophageal cancer-related mortality rate decreased from 27 to 8 per 100,000 person-years in China. By county, 577 (74%) of 782 counties experienced decreasing mortality. Geographic disparities in mortality substantially narrowed, with the gap in mortality rates between 90th and 10th percentile counties decreasing from 55 per 100,000 person-years in 1973-1975 to 16 in 2015-2017. However, clusters of elevated rates persisted across north-central China. Rurality [adjusted mortality rate ratio (MRR) 1.15; 95% confidence interval (CI), 1.10-1.21], per capita gross domestic product (adjusted MRR, 0.95; 95% CI, 0.91-0.98), and percentage of people with a high-school diploma (adjusted MRR, 0.86; 95% CI, 0.84-0.87) in a county were significantly associated esophageal cancer-related mortality rates. China has made substantial progress in reducing esophageal cancer-related mortality and disparities, but the intercounty differences remain large. Continued efforts are needed to address the geographical and socioeconomic disparities in esophageal cancer.