title: Immunochemical faecal occult blood testing to screen for colorectal cancer: can the screening interval be extended?
abstract: Colorectal cancer (CRC) screening programmes based on faecal immunochemical testing for haemoglobin (FIT) typically use a screening interval of 2 years. We aimed to estimate how alternative FIT strategies that use a lower than usual positivity threshold followed by a longer screening interval compare with conventional strategies.
  
  
  
  We analysed longitudinal data of 4523 Dutch individuals (50-74 years at baseline) participating in round I of a one-sample FIT screening programme, of which 3427 individuals also participated in round II after 1-3 years. The cohort was followed until 2 years after round II. In both rounds, a cut-off level of ≥50 ng haemoglobin (Hb)/mL buffer (corresponding to 10 µg Hb/g faeces) was used, representing the standard scenario. We determined the cumulative positivity rate (PR) and the numbers of subjects diagnosed with advanced adenomas (N_AdvAd) and early stage CRC (N_earlyCRC) in the cohort over two rounds of screening (standard scenario) and compared it with hypothetical single-round screening with use of a lower cut-off and omission of the second round (alternative scenario).
  
  
  
  In the standard scenario, the cumulative (ie, round I and II combined) PR, N_AdvAd and N_earlyCRC were 13%, 180% and 26%, respectively. In alternative scenarios using a cut-off level of respectively ≥11 and ≥22 ng/HbmL buffer (corresponding to 2 and 4 µg Hb/g faeces), the PRs were 18% and 13%, the N_AdvAd were 180 and 162 and the N_earlyCRC ranged between 22-27 and 22-26.
  
  
  
  The diagnostic yield of FIT screening using a lowered positivity threshold in combination with an extended screening interval (up to 5 years) may be similar to conventional FIT strategies. This justifies and motivates further research steps in this direction.
authors.affiliation: Department of Clinical Epidemiology, Leibniz Institute for Prevention Research and Epidemiology-BIPS, Bremen, Germany.|Faculty of Human and Health Sciences, University of Bremen, Bremen, Germany.
authors.forename: Ulrike
authors.initials: U
authors.lastname: Haug
authors.affiliation: Department of Gastroenterology and Hepatology, Erasmus University Medical Centre, Rotterdam, The Netherlands.
authors.forename: Esmée J
authors.initials: EJ
authors.lastname: Grobbee
authors.affiliation: Department of Public Health, Erasmus University Medical Centre, Rotterdam, The Netherlands.
authors.forename: Iris
authors.initials: I
authors.lastname: Lansdorp-Vogelaar
authors.affiliation: Department of Gastroenterology and Hepatology, Erasmus University Medical Centre, Rotterdam, The Netherlands.
authors.forename: Manon C W
authors.initials: MCW
authors.lastname: Spaander
authors.affiliation: Department of Gastroenterology and Hepatology, Erasmus University Medical Centre, Rotterdam, The Netherlands.
authors.forename: Ernst J
authors.initials: EJ
authors.lastname: Kuipers
mesh_terms: D000236:Adenoma / Q000175:diagnosis; D000368:Aged; D015179:Colorectal Neoplasms / Q000175:diagnosis*; D055088:Early Detection of Cancer; D005243:Feces / Q000737:chemistry*; D005260:Female; D006454:Hemoglobins / Q000032:analysis*; D006801:Humans; D007120:Immunochemistry; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009426:Netherlands; D009780:Occult Blood; D012016:Reference Values
chemical_list: D006454:Hemoglobins
keywords: COLORECTAL CANCER SCREENING