title: Post-colonoscopy colorectal cancers in average-risk Korean subjects with a normal initial colonoscopy.
abstract: OBJECTIVE
  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.
  
  
  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%).
  
  
  CONCLUSIONS
  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.
authors.affiliation: Department of Internal Medicine, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea. yscho@catholic.ac.kr.
authors.forename: Han Hee
authors.initials: HH
authors.lastname: Lee
authors.forename: Seung Kyoung
authors.initials: SK
authors.lastname: Kim
authors.forename: Hyun Ho
authors.initials: HH
authors.lastname: Choi
authors.forename: Hyung Keun
authors.initials: HK
authors.lastname: Kim
authors.forename: Sung Soo
authors.initials: SS
authors.lastname: Kim
authors.forename: Hiun Suk
authors.initials: HS
authors.lastname: Chae
authors.forename: Hyunjung
authors.initials: H
authors.lastname: Cho
authors.forename: Young Seok
authors.initials: YS
authors.lastname: Cho
mesh_terms: D000236:Adenoma / Q000175:diagnosis* / Q000453:epidemiology; D000368:Aged; D003113:Colonoscopy / Q000706:statistics & numerical data*; D015179:Colorectal Neoplasms / Q000175:diagnosis* / Q000453:epidemiology; D057210:Delayed Diagnosis / Q000706:statistics & numerical data*; D055088:Early Detection of Cancer / Q000379:methods / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D056910:Republic of Korea / Q000453:epidemiology; D012307:Risk Factors; D013997:Time Factors