Upper Gastrointestinal Cancer in China: Spatial Epidemiologic Evidence from Screening Areas.

Upper gastrointestinal cancer (UGIC) including esophageal cancer and gastric cancer, which has been a significant burden in China. Few studies have explored the spatial pattern and association of incidence and mortality using nationwide data. This study aims to explore the spatial pattern and association of incidence and mortality between esophageal cancer and gastric cancer, and identify high-risk areas of the cancers to provide scientific evidence for tailoring endoscopic screening programs. We collected UGIC data in 2014 from a National Cancer Report, and then adopted methods of correlation analysis and spatial statistics to identify high-risk areas on the cancers and to explore the pattern. The results show a spatial autocorrelation on the spatial distribution of incidence and mortality of esophageal and gastric cancers, and the relative risks were from 2.52 (95% CI (confidence interval), 2.37-2.67; < 0.001) to 3.80 (95% CI, 3.46-4.18; < 0.001) in primary risk areas, respectively. Moreover, esophageal cancer shows an upward and then downward trend from west to east, and from south to north, yet gastric cancer exhibits an upward and then downward trend only from south to north. This study indicates habitants in overlapping risk areas have heavier cancer burdens, and suggests esophageal cancer and gastric cancer have a significant correlation. Therefore, more endoscopic screening attention should focus on overlapping risk areas.