title: Diagnostic yield in a biennial Hemoccult-II screening program compared to a once-only screening with flexible sigmoidoscopy and Hemoccult-II.
abstract: BACKGROUND
  Flexible sigmoidoscopy (FS) has a higher degree of sensitivity for detecting colorectal neoplasia in the left side of the colon than Hemoccult (H-II). However, no randomized controlled trial has compared a single FS screening with a H-II screening program (annual or biennial) despite the well-documented mortality reduction from colorectal cancer (CRC) in the latter. The aim was to compare the diagnostic yield of colorectal neoplasia in two aged-matched groups from two different randomized screening trials; one group screened by a single FS+H-II, the other with biennial H-II over the course of 16 years.
  
  
  METHODS
  24,465 persons invited to participate in the Funen biennial H-II screening program were compared with 4,460 similar persons invited to another Funen trial using a single FS+H-II.
  
  
  RESULTS
  Compliance in the biennial H-II program was 65.5% during the first screening round compared to 39.8% for FS+H-II. The cumulative number of persons with positive tests was 8.2% (positive H-II) in the biennial H-II program during 16 years and 20.3% (polyps > 3 mm in diameter seen at FS or positive H-II) for once-only FS+H-II. The diagnostic yield of CRC per 1,000 screened was 9.9 in the biennial H-II program and 6.6 after FS+H-II (6.5 and 2.7 per 1,000 invited). The yield of advanced adenomas (> or = 10 mm and/or villous structure and/or severe dysplasia) was 2.3% in the H-II program and 3.3% after FS+H-II among the screened persons, but this difference disappeared when persons invited, but not necessarily screened, were compared (1.5% versus 1.3%).
  
  
  CONCLUSIONS
  Screening with H-II in a biennial screening program during 16 years detected more CRCs than a single screening with FS+H-II and a similar number of advanced adenomas.
authors.affiliation: Dept. of Surgery A, Odense University Hospital, Odense, Denmark. mo.rasmussen@dadlnet.dk
authors.forename: M
authors.initials: M
authors.lastname: Rasmussen
authors.forename: C
authors.initials: C
authors.lastname: Fenger
authors.forename: O
authors.initials: O
authors.lastname: Kronborg
mesh_terms: D000236:Adenoma / Q000175:diagnosis*; D000368:Aged; D015179:Colorectal Neoplasms / Q000175:diagnosis*; D006801:Humans; D008403:Mass Screening / Q000379:methods; D008875:Middle Aged; D009780:Occult Blood; D012680:Sensitivity and Specificity; D012812:Sigmoidoscopy / Q000379:methods*