title: Incidence and prognosis of colorectal dysplasia in inflammatory bowel disease: a population-based study from Olmsted County, Minnesota.
abstract: OBJECTIVE
  The risk, fate, and ideal management of colorectal dysplasia in inflammatory bowel disease (IBD) remain debated. We estimated the incidence, long-term outcome, and risk factors for progression of colorectal dysplasia (adenomas [adenoma-associated lesions or masses (ALMs)], flat dysplasia, and dysplasia-associated lesions or masses [DALMs]) in a population-based IBD cohort from Olmsted County, Minnesota.
  
  
  METHODS
  The Rochester Epidemiology Project was used to identify cohort patients with colorectal dysplasia. Medical records were reviewed for demographic and clinical characteristics. Histology slides were reviewed by a pathologist blinded to previous pathology reports. The cumulative incidence of dysplasia was estimated, and the association between patient characteristics and recurrence/progression of dysplasia was assessed using proportional hazards regression.
  
  
  RESULTS
  Twenty-nine (4%) IBD patients developed flat dysplasia (n = 8), DALMs (n = 1), ALMs in areas of IBD (n = 18), or ALMs outside areas of IBD (n = 2). Among 6 patients with flat low-grade dysplasia (fLGD) who did not undergo colectomy, none progressed during a median of 17.8 (range 6-21) years of observation with a median of 3 (range 0-12) surveillance colonoscopies. Four (22%) patients with ALMs in areas of IBD who did not undergo surgery developed LGD or DALMs. Primary sclerosing cholangitis and dysplasia located proximal to the splenic flexure were significantly associated with risk for recurrence/progression of dysplasia.
  
  
  CONCLUSIONS
  This population-based cohort study from Olmsted County, Minnesota did not confirm an increased risk of cancer related to fLGD, whereas 22% of patients with ALMs in areas of IBD developed fLGD or DALMs.
authors.affiliation: Department of Medical Gastroenterology, Herlev University Hospital, Herlev, Denmark.
authors.forename: Tine
authors.initials: T
authors.lastname: Jess
authors.forename: Edward V
authors.initials: EV
authors.lastname: Loftus
authors.forename: Fernando S
authors.initials: FS
authors.lastname: Velayos
authors.forename: W Scott
authors.initials: WS
authors.lastname: Harmsen
authors.forename: Alan R
authors.initials: AR
authors.lastname: Zinsmeister
authors.forename: Thomas C
authors.initials: TC
authors.lastname: Smyrk
authors.forename: William J
authors.initials: WJ
authors.lastname: Tremaine
authors.forename: L Joseph
authors.initials: LJ
authors.lastname: Melton
authors.forename: Pia
authors.initials: P
authors.lastname: Munkholm
authors.forename: William J
authors.initials: WJ
authors.lastname: Sandborn
mesh_terms: D000236:Adenoma / Q000453:epidemiology* / Q000209:etiology; D015331:Cohort Studies; D003093:Colitis, Ulcerative / Q000150:complications* / Q000473:pathology; D003106:Colon / Q000473:pathology*; D015179:Colorectal Neoplasms / Q000453:epidemiology* / Q000209:etiology; D003424:Crohn Disease / Q000150:complications* / Q000473:pathology; D018450:Disease Progression; D005260:Female; D006801:Humans; D015994:Incidence; D008137:Longitudinal Studies; D008297:Male; D008910:Minnesota / Q000453:epidemiology; D011230:Precancerous Conditions / Q000453:epidemiology / Q000209:etiology; D011379:Prognosis; D012007:Rectum / Q000473:pathology*; D012306:Risk