title: Randomized study of biennial screening with a faecal occult blood test: results after nine screening rounds.
abstract: BACKGROUND
  Two large true population studies in Europe have shown a significant reduction in mortality from colorectal cancer (CRC) by screening with a faecal occult blood test. In one trial conducted in Funen County, 61,933 individuals (aged 45-75 years) were randomly allocated either to a control group or to receive a biennial Hemoccult-II test.
  
  
  METHODS
  These individuals were followed from 1985 to 2002 and 9 screening rounds were performed.
  
  
  RESULTS
  First screening was accepted by 67% (20,672). Positivity rates varied between 0.8% and 3.8%, and the cumulative proportion of the test group having colonoscopy was 5.3%. Screen-detected CRC was early (Dukes' A) in 36% compared to 11% among controls. Incidence of CRC was unchanged, but mortality was reduced by 11%. This figure increased to 43% in persons participating in all 9 rounds. No more than 8,558 were screened at the 9th round. Patients with CRC detected between screenings had better survival than controls. Death rates from causes other than CRC among participants never became higher than among controls.
  
  
  CONCLUSIONS
  The lesser reduction in mortality from CRC of 11% compared to 18% after 5 screening rounds may be explained by the decrease in the number screened. Efficacy in those screened supports the introduction of countrywide screening in Denmark, but it must be ascertained that acceptability, proportion of early CRC and logistics all reach the same standard as in the randomized trial.
authors.affiliation: Department of Surgery A, Odense University Hospital, Linde Alle 32, DK-5230 Odense, Denmark. ole.kronborg@dadlnet.dk
authors.forename: O
authors.initials: O
authors.lastname: Kronborg
authors.forename: O D
authors.initials: OD
authors.lastname: Jørgensen
authors.forename: C
authors.initials: C
authors.lastname: Fenger
authors.forename: M
authors.initials: M
authors.lastname: Rasmussen
mesh_terms: D000236:Adenoma / Q000175:diagnosis* / Q000453:epidemiology*; D017677:Age Distribution; D000368:Aged; D003113:Colonoscopy / Q000379:methods; D015179:Colorectal Neoplasms / Q000175:diagnosis* / Q000401:mortality*; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008403:Mass Screening / Q000379:methods*; D008875:Middle Aged; D009780:Occult Blood; D011237:Predictive Value of Tests; D012016:Reference Values; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D017678:Sex Distribution; D016019:Survival Analysis