Objective (background): We aimed to investigate the clinical characteristics of superficial non-ampullary duodenal epithelial tumors (SNADET) in endoscopic screening, using a thin endoscope. These are not clearly described the literature.

Subjects and methods: We conducted a single-center retrospective analysis. Among 73,959 subjects who underwent endoscopic screening at Japanese Red Cross Kyoto Daini Hospital over 16 years—between April 2006 and March 2022, we detected SNADET in a total of 36 cases (adenoma, n=20; early cancer, n=16). In each case, we evaluated the patient’s age and sex. We also assessed the endoscope model used and the clinicopathological findings of endoscopic-screening treatment, final histological diagnosis, SNADET-detection rate, cancer-detection rate, and early-cancer ratio. We also determined the diagnostic accuracy of biopsies in endoscopic screening and conducted an endoscopic evaluation of gastric atrophy, based on the following sources: the Kimura-Takemoto classification; the diagnostic and therapeutic terminology of the Japan Endoscopy Database Project; the history and eradication of Helicobacter pylori infections; and the recent history of endoscopy over the past three years.

Results: The overall SNADET-detection rate was 0.049%; the rate achieved using a transoral thin endoscope was 0.046% and that achieved using a transnasal ultrathin endoscope was 0.089%. The overall cancer-detection rate was 0.022% in 16 cases, all of which involved early-stage cancers. Of the 15 cases of adenocarcinoma diagnosed histologically after endoscopic treatment at our hospital, 7 cases were diagnosed as adenocarcinoma by biopsy in endoscopic screening. The diagnostic accuracy of the biopsies was only 46.7%; they also induced fibrosis in the submucosa in four cases, making subsequent endoscopic resection difficult.

Conclusions: The rate of SNADET detection achieved using a thin endoscope was similar to that reported in previous studies. Moreover, the detection rate achieved using a transnasal ultrathin endoscope was no worse than that achieved using a transoral thin scope. Endoscopic screening with these instruments is useful for the early detection of SNADET. Future endoscopic-screening research should focus on the need to observe the second section of the duodenum and the adequacy of routine biopsies when considering endoscopic treatment for SNADET.

We conducted a familiarization and standardization of Helicobacter pylori (H. pylori) eradication program in Yamagata Prefecture and established the Yamagata Prefecture H. pylori study group when H. pylori eradication was covered by the National Health Insurance in November 2000. Subsequently, we conducted an 8-year prospective cohort study of the effect of H. pylori eradication on gastric cancer suppression, which showed a 40% reduction in gastric cancer in patients who underwent H. pylori eradication compared to those who did not. The effect of H. pylori eradication was also confirmed by a collaborative study between the Yamagata City Medical Association and Yamagata University between 2010 and 2011. The results revealed that X-ray gastric cancer screening combined with the ABC classification detected 3 times more gastric cancer than that of X-ray screening alone. These results prompted Yamagata City to continue the X-ray gastric cancer screening program combined with the ABC classification including financial support for the ABC class evaluation and H. pylori eradication. This program re-confirmed the usefulness of gastric cancer screening and the successful H. pylori eradication in infected patients over four years and provided opportunities to examine the present status and identify any outstanding issues. In 2014, WHO/IARC published a report recommending H. pylori eradication for gastric cancer prevention, and the Ministry of Health, Labor, and Welfare published a revised “Japanese Guideline for Gastric Cancer Screening” in 2016. Following these publications, Digestive System Disease Screening Central Committee of Yamagata Prefecture Medical Association also established a screening system, which aimed to provide H. pylori eradication for gastric cancer prevention education to patients diagnosed with chronic gastritis to encourage them to undergo H. pylori eradication for the reduction of gastric cancer risk. The diagnosis was based on the categorized criteria for the gastric mucosal pattern using the upper GI series defined by the Japanese Society of Gastrointestinal Cancer Screening (category 2 “chronic gastritis”).

Background: The participation rate for diagnostic examinations for colorectal cancer screening is low. Low acceptability of colonoscopy is one of the reasons for this. However, the introduction of computed tomography (CT) colonography as a second-line examination is expected to improve the participation rate.

Subjects and methods: A questionnaire survey was conducted to estimate whether the addition of CT colonography to the diagnostic examination options would increase the participation rate. In addition, the acceptability of colonoscopy as the first-line examination was investigated.

Results: The estimated increase in the participation rate for diagnostic examinations was 4.7% (25/533, 95% confidence interval 3.1-6.8%). Although physicians strongly recommended colonoscopy, 2% of participants underwent CT colonography. In the pre-examination questionnaire, 37.6% of all participants had a bad impression of colonoscopy, and 52.8% of those who had never undergone a colonoscopy had a bad impression of colonoscopy. In the post-examination questionnaire, participants were more willing to undergo colonoscopy in the future if the colonoscopy was performed by a physician who frequently performs low-discomfort colonoscopy.

Conclusions: The addition of CT colonography to the diagnostic examination options is expected to increase the participation rate. For participants who reject colonoscopy, CT colonography is useful as an alternative examination. Many participants have a bad impression of colonoscopy, and performing comfortable colonoscopies is important because it is related to future acceptability.