title: Clinical significance of small colorectal adenoma less than 10 mm: the KASID study.
abstract: OBJECTIVE
  Polypectomy is the current modality of choice to prevent benign colorectal adenoma from progressing to an invasive cancer. However, in cases of small colorectal adenoma, it remains unclear as to whether polypectomy is actually an effective treatment modality. We evaluated the clinical significance of polypectomy in cases of small colorectal adenomas, measuring less than 10 mm.
  
  
  METHODS
  All colonoscopies were performed at 11 Korean tertiary medical centers, between July 2003 and March 2004. A total of 5996 colorectal adenomas were detected and divided into 5 groups according to their size (Group 1; 1-5 mm, Group 2; 6-7 mm, Group 3; 8-9 mm, Group 4; 10-19 mm, Group 5; more than 20 mm). The term 'advanced adenoma' refers here to tubular adenomas with diameters of at least 10 mm, or to tubulovillous, villous, or high-grade dysplasia, irrespective of size. 'Cancer' here is defined as the invasion of malignant cells beyond the muscularis mucosa.
  
  
  RESULTS
  As the sizes of the adenomas increased, the prevalence of advanced adenoma was also observed to increase. In Groups 2 and 3, the prevalence of tubulovillous or villous adenoma were higher than was expected (5.2% and 6.6%, p < 0.001). Interestingly enough, in Group 2, the prevalence of cancer was at least as high as in Group 4 (0.7% vs. 0.5%, p < 0.001).
  
  
  CONCLUSIONS
  In cases of small colorectal adenomas, measuring between 6 and 9 mm, the prevalence of cancer was at least as high as that seen in the cases of colorectal adenomas measuring between 10 and 19 mm. Therefore, small colorectal adenomas measuring between 6 and 9 mm should not be ignored, in order to decrease the prevalence of colorectal cancer.
authors.affiliation: Department of Internal Medicine, Kangbuk Samsung Hospital, Korea.
authors.forename: Tae Woo
authors.initials: TW
authors.lastname: Yoo
authors.forename: Dong Il
authors.initials: DI
authors.lastname: Park
authors.forename: Young-Ho
authors.initials: YH
authors.lastname: Kim
authors.forename: Hyun Soo
authors.initials: HS
authors.lastname: Kim
authors.forename: Won Ho
authors.initials: WH
authors.lastname: Kim
authors.forename: Tae Il
authors.initials: TI
authors.lastname: Kim
authors.forename: Hyo Jong
authors.initials: HJ
authors.lastname: Kim
authors.forename: Suk-Kyun
authors.initials: SK
authors.lastname: Yang
authors.forename: Jeong-Sik
authors.initials: JS
authors.lastname: Byeon
authors.forename: Moon Sung
authors.initials: MS
authors.lastname: Lee
authors.forename: Il Kwon
authors.initials: IK
authors.lastname: Jung
authors.forename: Moon Kwan
authors.initials: MK
authors.lastname: Chung
authors.forename: Sung-Ae
authors.initials: SA
authors.lastname: Jung
authors.forename: Yoon Tae
authors.initials: YT
authors.lastname: Jeen
authors.forename: Jai Hyun
authors.initials: JH
authors.lastname: Choi
authors.forename: Hwang
authors.initials: H
authors.lastname: Choi
authors.forename: Dong Soo
authors.initials: DS
authors.lastname: Han
authors.forename: Jae Suk
authors.initials: JS
authors.lastname: Song
mesh_terms: D018253:Adenoma, Villous / Q000175:diagnosis / Q000473:pathology / Q000601:surgery; D018256:Adenomatous Polyps / Q000175:diagnosis* / Q000473:pathology / Q000601:surgery; D000328:Adult; D000368:Aged; D002471:Cell Transformation, Neoplastic / Q000473:pathology; D015331:Cohort Studies; D003113:Colonoscopy; D015179:Colorectal Neoplasms / Q000175:diagnosis* / Q000473:pathology / Q000601:surgery; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007413:Intestinal Mucosa / Q000473:pathology / Q000601:surgery; D008297:Male; D008875:Middle Aged; D011230:Precancerous Conditions / Q000175:diagnosis* / Q000473:pathology / Q000601:surgery; D012307:Risk Factors