title: High-risk metachronous polyps are more frequent in patients with traditional serrated adenomas than in patients with conventional adenomas: a multicenter prospective study.
abstract: OBJECTIVE
  Although the malignant progression of serrated polyps has been clearly documented, the malignant potential of the traditional serrated adenoma (TSA) subtype has not been established. We compared the prevalence of metachronous polyps in surveillance colonoscopies between patients with TSA and those with conventional adenomas (CAs).
  
  
  METHODS
  Four hundred twenty patients were diagnosed with TSAs by current diagnostic criteria at 10 tertiary care university hospitals in Korea from January 2003 to December 2005; 186 patients who received surveillance colonoscopy after removal of initial polyps were enrolled. During the same time period, 372 age- and sex-matched patients diagnosed with CAs were used as a control group.
  
  
  RESULTS
  TSA patients had a significantly higher recurrence rate of colorectal polyps compared with CA patients (66.1% vs 43.5%, respectively). TSA patients had a greater number (3 vs 2) and larger size (8.6 ± 5.7 vs 6.3 ± 5.2 mm) of recurrent polyps compared with CA patients. TSA patients also had a higher rate of CA (54.8% vs 37.9%), serrated adenoma (14.0% vs. 0.8%), and hyperplastic polyp (33.3% vs. 13.7%) recurrence compared with CA patients. TSA patients had significantly greater odds of having a recurrent high-risk polyp than CA patients (odds ratio, 2.37; 95% confidence interval, 1.55-3.63).
  
  
  CONCLUSIONS
  In comparison with patients with CAs, patients with TSAs have a higher metachronous occurrence rate of all polyp subtypes including CAs, serrated adenomas, and hyperplastic polyps. Moreover, the presence of TSAs is an independent predictor of a high-risk polyp occurrence.
authors.affiliation: Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Jin Young
authors.initials: JY
authors.lastname: Yoon
authors.affiliation: Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Hyung Tae
authors.initials: HT
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Sung Pil
authors.initials: SP
authors.lastname: Hong
authors.affiliation: Soonchunhyang University College of Medicine, Seoul, Cheonan, Korea.
authors.forename: Hyun Gun
authors.initials: HG
authors.lastname: Kim
authors.affiliation: Soonchunhyang University College of Medicine, Seoul, Cheonan, Korea.
authors.forename: Jin-Oh
authors.initials: JO
authors.lastname: Kim
authors.affiliation: University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Dong-Hoon
authors.initials: DH
authors.lastname: Yang
authors.affiliation: Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Dong Il
authors.initials: DI
authors.lastname: Park
authors.affiliation: Kosin University College of Medicine, Pusan, Korea.
authors.forename: Seun Ja
authors.initials: SJ
authors.lastname: Park
authors.affiliation: Yonsei University, Wonju College of Medicine, Wonju, Korea.
authors.forename: Hyun-Soo
authors.initials: HS
authors.lastname: Kim
authors.affiliation: Korea University College of Medicine, Seoul, Korea.
authors.forename: Bora
authors.initials: B
authors.lastname: Keum
authors.affiliation: Hallym University College of Medicine, Pyeongchon, Korea.
authors.forename: Cheol Hee
authors.initials: CH
authors.lastname: Park
authors.affiliation: Hanyang University College of Medicine, Guri, Korea.
authors.forename: Chang Soo
authors.initials: CS
authors.lastname: Eun
authors.affiliation: Soonchunhyang University College of Medicine, Seoul, Cheonan, Korea.
authors.forename: Suck-Ho
authors.initials: SH
authors.lastname: Lee
authors.affiliation: Hallym University College of Medicine, Pyeongchon, Korea.
authors.forename: Il Hyun
authors.initials: IH
authors.lastname: Baek
authors.affiliation: Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Dong Kyung
authors.initials: DK
authors.lastname: Chang
authors.affiliation: Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Tae Il
authors.initials: TI
authors.lastname: Kim
mesh_terms: D000236:Adenoma / Q000453:epidemiology / Q000473:pathology*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D003110:Colonic Neoplasms / Q000453:epidemiology / Q000473:pathology*; D003111:Colonic Polyps / Q000453:epidemiology / Q000473:pathology*; D003113:Colonoscopy; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D016609:Neoplasms, Second Primary / Q000453:epidemiology / Q000473:pathology*; D015995:Prevalence; D011446:Prospective Studies; D056910:Republic of Korea / Q000453:epidemiology