title: The Norwegian Colorectal Cancer Prevention (NORCCAP) screening study: baseline findings and implementations for clinical work-up in age groups 50-64 years.
abstract: BACKGROUND
  Randomized controlled trials of sufficient power testing the long-term effect of screening for colorectal neoplasia only exist for faecal occult blood testing (FOBT). There is indirect evidence that flexible sigmoidoscopy (FS) may have a greater yield. The aim of this study was to determine the diagnostic yield of screening with FS or a combination of FS and FOBT in an average-risk population in an urban and combined urban and rural population in Norway.
  
  
  METHODS
  20,780 men and women (1:1), aged 50-64 years, were invited for once-only screening (FS only or a combination of FS and FOBT (1:1)) by randomization from the population registry. A positive FS was defined as a finding of any neoplasia or any polyp > or = 10 mm. A positive FS or FOBT qualified for colonoscopy.
  
  
  RESULTS
  Overall attendance was 65%. Forty-one (0.3%) cases of CRC were detected. Any adenoma was found in 2208 (17%) participants and 545 (4.2%) had high-risk adenomas. There was no difference in diagnostic yield between the FS and the FS and FOBT group regarding CRC or high-risk adenoma. Work-up load comprised 2821 colonoscopies in 2524 (20%) screenees and 10% of screenees were recommended later colonoscopy surveillance. There were no severe complications at FS, but six perforations after therapeutic colonoscopy (1:336).
  
  
  CONCLUSIONS
  The present study bodes well for future management of a national screening programme, provided that follow-up results reflect adequate proof of a net benefit. It is highly questionable whether the addition of once-only FOBT to FS will contribute to this effect.
authors.affiliation: The Cancer Registry of Norway, Institute of Population-based Cancer Research, Montebello, Oslo, Norway.
authors.forename: G
authors.initials: G
authors.lastname: Gondal
authors.forename: T
authors.initials: T
authors.lastname: Grotmol
authors.forename: B
authors.initials: B
authors.lastname: Hofstad
authors.forename: M
authors.initials: M
authors.lastname: Bretthauer
authors.forename: T J
authors.initials: TJ
authors.lastname: Eide
authors.forename: G
authors.initials: G
authors.lastname: Hoff
mesh_terms: D000230:Adenocarcinoma / Q000175:diagnosis* / Q000628:therapy; D000236:Adenoma / Q000175:diagnosis* / Q000628:therapy; D002276:Carcinoid Tumor / Q000175:diagnosis / Q000628:therapy; D003082:Colectomy / Q000379:methods; D003111:Colonic Polyps / Q000175:diagnosis* / Q000628:therapy; D015179:Colorectal Neoplasms / Q000175:diagnosis* / Q000628:therapy; D005260:Female; D006801:Humans; D008297:Male; D008403:Mass Screening / Q000379:methods*; D008875:Middle Aged; D009664:Norway; D009780:Occult Blood; D011446:Prospective Studies; D012424:Rural Population; D012812:Sigmoidoscopy / Q000379:methods*; D014505:Urban Population