2020 Volume 58 Issue 6 Pages 1015-1024
We defined "interval colorectal cancer," conducted total colonoscopy (TCS) within 3 years, and detected advanced cancer this time. We reviewed its characteristics to improve the accuracy of the colonoscopy. For eight years from April 2010 to March 2018, 43,852 TCS cases were examined at our center, and 3,020 malignant tumors were detected; the prevalence of interval advanced cancers was 19 (0.6%). Several of them were detected in the site with deep haustra, such as Cecum or Ascending colon or poorly extended lesion due to diverticulum. Additionally, there were several other reasons such as poor preparation before colonoscopy, lack of information on the surgical procedure after surgery, occurrence in the diverticulum, and adenoma progression. To improve the accuracy of TCS, which is a secondary precision examination for colorectal cancer screening, we must conduct the colonoscopy by keeping in mind the poor observation site of the colon.
