title: [Patterns of metachronous adenoma after colorectal cancer surgery].
abstract: OBJECTIVE
  After colorectal cancer surgery, colonoscopic surveillance should be done for prevention and early detection of secondary cancer. This study aimed to identify the group with high risk of developing colorectal adenoma after curative surgery of colorectal cancer.
  
  
  METHODS
  We retrospectively investigated the medical records of the subjects of 130 patients who had been examined using colonoscopy before and after the curative surgery.
  
  
  RESULTS
  The average age was 59.4 years. Synchronous adenomas were in 42 patients (32.3%). The occurrence rate was significantly high in men (38.8%) than women (22.0%). After the operation, the mean interval of examining colonoscopy was 11.6 months (3-24 months) and metachronous adenomas were detected in 26 patients (20.0%). The patients who have both metachronous and synchronous adenomas were observed in 13/42 (30.9%) and the patients of metachronous adenomas without synchronous adenomas were observed in 13/88 (14.8%). The occurrence rate of metachronous adenomas with synchronous adenomas was significantly high. The frequency of synchronous adenomas didn't increase with age. However, the frequency of metachronous adenomas increased with age: 0/9 (0%) under 40 years, 7/49 (14.3%) in 41-61 years and 19/72 (26.4%) over 61 years. The occurrence rate was higher in men (26.3%) than women (10.0%).
  
  
  CONCLUSIONS
  The occurrence rate of metachronous adenomas after colorectal cancer surgery was higher in the patients with synchronous adenomas, male gender and old aged patients.
authors.affiliation: Department of Internal Medicine, Chungnam National University College of Medicine, Daejeon, Korea.
authors.forename: Byung Kyu
authors.initials: BK
authors.lastname: Nah
authors.forename: Sun Moon
authors.initials: SM
authors.lastname: Kim
authors.forename: Yeum Seok
authors.initials: YS
authors.lastname: Lee
authors.forename: Hyeon Woong
authors.initials: HW
authors.lastname: Yang
authors.forename: Seung Weon
authors.initials: SW
authors.lastname: Seo
authors.forename: Jae Kyu
authors.initials: JK
authors.lastname: Sung
authors.forename: Byung Seok
authors.initials: BS
authors.lastname: Lee
authors.forename: Hyun Yong
authors.initials: HY
authors.lastname: Jeong
mesh_terms: D000236:Adenoma / Q000175:diagnosis*; D000328:Adult; D000368:Aged; D003113:Colonoscopy; D015179:Colorectal Neoplasms / Q000601:surgery*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009378:Neoplasms, Multiple Primary / Q000175:diagnosis; D016609:Neoplasms, Second Primary / Q000175:diagnosis*; D012307:Risk Factors