Abstract
This study analyzed the detection rates of gastric cancer (GC) among serial participants in the radiographic screening test in the 2016 fiscal year, who had already been classified into Category (Cate)-1 and Cate-2 by the test in the 2015 fiscal year, according to the categorized criteria for X-ray image reading of the population-based GC screening, which has been published by the Japanese Society of Gastrointestinal Cancer Screening. The detection rate of GC in the Cate-1 group in the 2nd round screening test was 0.009%, indicating an extremely low risk of GC detection, but that of the Cate-2 group was 0.239%, which was significantly higher than that of Cate-1 (p < 0.001). The detection rate of GC among males in the Cate-2 group was 0.364%, whereas that among females was 0.115%, indicating a significantly higher rate of GC detection in males than in females (p < 0.001). In addition, the Cate-2 group (aged 50-79 years) with a history of Helicobacter pylori treatment and those with successful eradication had significantly low detection rates of GC at 0.145% and 0.142%, respectively, in comparison with 0.364% in the Cate-2 group without the therapy. The odds ratios (95% confidence intervals) of the Cate-2 group with the treatment history and successful eradication versus those without treatment history were 0.558 (0.326-0.955) and 0.547 (0.302-0.990), respectively. These data indicate the possibility that Helicobacter pylori eradication therapy might possess a preventive effect on GC. Based on these findings, the assumption of GC risk by distinguishing between Cate-1 and Cate-2 in the X-ray image reading, considering the differences in gender and the status of Helicobacter pylori eradication, might contribute to the improvement of GC detection in the population-based screening for GC.
