Prevalence of gastric cancer following colorectal endoscopic submucosal dissection for lesions more than 20 mm: A retrospective analysis.

Objectives: Colorectal endoscopic submucosal dissection (ESD) for large tumors is spreading worldwide. Gastric cancer (GC) sometimes occurs after colorectal ESD. However, its status including frequency and risk factors have not been examined well. In this study, we analyzed the detailed status of GC after colorectal ESD. Methods: This was a single-center retrospective study. Patients receiving colorectal ESD between 2010 and 2018 were reviewed. All patients were recommended to receive esophagogastroduodenoscopy (EGD) for screening. Finally, 436 patients receiving EGD, who underwent colorectal ESD for lesions of ≥20 mm were analyzed. The primary outcome was the GC rate after colorectal ESD, including intramucosal cancer. As a control, we compared it to the GC rate in matched Japanese national cancer registry data. The secondary outcome was risk factors for developing GC. Results: The mean age was 66.9 ± 10.6 and 55.3% were males. The GC rate was 5.96% (26/436) with a median observation period of 27 months. It was significantly higher than the mean GC rate in the diagnosed age calculated with the cancer registry (0.26%, observed value/expected value ratio [95% confidence interval]: 22.20 [14.50-32.53], Conclusion: The GC rate was high after resecting colorectal tumors of ≥20 mm, suggesting the necessity of EGD.