Turkish Journal of Gastroenterology
Original Article

Post-colonoscopy colorectal cancers in average-risk Korean subjects with a normal initial colonoscopy


Department of Internal Medicine, Seoul St. Mary’s Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea


Department of Internal Medicine, Uijeongbu St. Mary’s Hospital, College of Medicine, The Catholic University of Korea, Uijeongbu, Korea


MOT Cluster, Korea University of Technology and Education, Cheonan, Korea

Turk J Gastroenterol 2016; 27: 17-22
DOI: 10.5152/tjg.2015.150286
Read: 1826 Downloads: 812 Published: 25 July 2019


Background/Aims: There are relatively few studies regarding the incidence of post-colonoscopy colorectal cancer (PCCRC) in Asian countries. We evaluated the characteristics of PCCRC in average-risk Korean subjects.


Materials and Methods: This study included subjects who were ≥50 years of age and had undergone a first completed colonoscopy between January 2001 and December 2004, at which no baseline adenoma had been detected, followed by a second colonoscopy 1–5 years later. The incidences and characteristics of advanced neoplasia in these subjects were assessed.


Results: A total of 343 subjects underwent follow-up colonoscopy within 5 years. Seventy-three (21.3%) subjects were found to have at least one adenoma on follow-up colonoscopy. Advanced adenoma was found in eight (2.3%) subjects, and non-advanced adenomas were found in 65 (19.0%). Five (1.5%) subjects were diagnosed with invasive CRC following a normal colonoscopy. The putative reason for PCCRCs was missed lesions in two (40.0%) subjects and a new cancer in three (60.0%).


Conclusion: The risk of advanced neoplasia (including PCCRCs) within 5 years after a normal baseline colonoscopy in our cohort was not low. Considering that 40% of PCCRCs were attributable to missed lesions, our results emphasize the need for technical improvement of colonoscopic examinations to improve adenoma detection.

EISSN 2148-5607