The spatiotemporal associations between esophageal and gastric cancers provide evidence for its joint endoscopic screening in China: a population-based study

Background: The spatiotemporal epidemiological evidence supporting joint endoscopic screening for esophageal cancer (EC) and gastric cancer (GC) remains limited. This study aims to identify combined high-risk regions for EC and GC and determine optimal areas for joint and separate endoscopic screening.

Methods: We analyzed the association of incidence trends between EC and GC in cancer registry areas across China from 2006 to 2016 using spatiotemporal statistical methods. Based on these analyses, we divided different combined risk regions for EC and GC to implement joint endoscopic screening.

Results: From 2006 to 2016, national incidence trends for both EC and GC showed a decline, with an average annual percentage change of -3.15 (95% confidence interval [CI]: -5.33 to -0.92) for EC and -3.78 (95% CI: -4.98 to -2.56) for GC. A grey comprehensive correlation analysis revealed a strong temporal association between the incidence trends of EC and GC, with correlations of 79.00% (95% CI: 77.85 to 80.14) in males and 77.62% (95% CI: 76.50 to 78.73) in females. Geographic patterns of EC and GC varied, demonstrating both homogeneity and heterogeneity across different regions. The cancer registry areas were classified into seven distinct combined risk regions, with 33 areas identified as high-risk for both EC and GC, highlighting these regions as priorities for joint endoscopic screening.

Conclusion: This study demonstrates a significant spatiotemporal association between EC and GC. The identified combined risk regions provide a valuable basis for optimizing joint endoscopic screening strategies for these cancers.