title: Performance of a quantitative fecal immunochemical test in a colorectal cancer screening pilot program: a prospective cohort study.
abstract: BACKGROUND
  British Columbia undertook a colorectal cancer screening pilot program in 3 communities. Our objective was to assess the performance of 2-specimen fecal immunochemical testing in the detection of colorectal neoplasms in this population-based screening program.
  
  
  METHODS
  A prospective cohort of asymptomatic, average-risk people aged 50 to 74 years completed 2 quantitative fecal immunochemical tests every 2 years, with follow-up colonoscopy if the result of either test was positive. Participant demographics, fecal immunochemical test results, colonoscopy quality indicators and pathology results were recorded. Non-screen-detected colorectal cancer that developed in program participants was identified through review of data from the BC Cancer Registry.
  
  
  RESULTS
  A total of 16 234 people completed a first round of fecal immunochemical testing, with a positivity rate of 8.6%; 5378 (86.0% of eligible participants) completed a second round before the end of the pilot program, with a positivity rate of 6.7%. Of the 1756 who had a positive test result, 1555 (88.6%) underwent colonoscopy. The detection rate of colorectal cancer was 3.5 per 1000 participants. The positive predictive value of the fecal immunochemical test was 4.9% (95% confidence interval [CI] 3.8%-6.0%) for colorectal cancer, 35.0% (95% CI 32.5%-37.2%) for high-risk polyps and 62.0% (95% CI 59.6%-64.4%) for all neoplasms. The number needed to screen was 283 to detect 1 cancer, 40 to detect 1 high-risk polyp and 22 to detect any neoplasm.
  
  
  CONCLUSIONS
  Screening every 2 years with a 2-specimen fecal immunochemical test surpassed the current benchmark for colorectal cancer detection in population-based screening. This study has implications for other jurisdictions planning colorectal cancer screening programs.
authors.affiliation: Department of Medicine (Telford) and School of Population and Public Health (Coldman), University of British Columbia; Departments of Population Oncology (Telford, Gentile, Gondara, McGahan) and Cancer Control Research (Coldman), British Columbia Cancer Agency, Vancouver, BC.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Telford
authors.affiliation: Department of Medicine (Telford) and School of Population and Public Health (Coldman), University of British Columbia; Departments of Population Oncology (Telford, Gentile, Gondara, McGahan) and Cancer Control Research (Coldman), British Columbia Cancer Agency, Vancouver, BC.
authors.forename: Laura
authors.initials: L
authors.lastname: Gentile
authors.affiliation: Department of Medicine (Telford) and School of Population and Public Health (Coldman), University of British Columbia; Departments of Population Oncology (Telford, Gentile, Gondara, McGahan) and Cancer Control Research (Coldman), British Columbia Cancer Agency, Vancouver, BC.
authors.forename: Lovedeep
authors.initials: L
authors.lastname: Gondara
authors.affiliation: Department of Medicine (Telford) and School of Population and Public Health (Coldman), University of British Columbia; Departments of Population Oncology (Telford, Gentile, Gondara, McGahan) and Cancer Control Research (Coldman), British Columbia Cancer Agency, Vancouver, BC.
authors.forename: Colleen
authors.initials: C
authors.lastname: McGahan
authors.affiliation: Department of Medicine (Telford) and School of Population and Public Health (Coldman), University of British Columbia; Departments of Population Oncology (Telford, Gentile, Gondara, McGahan) and Cancer Control Research (Coldman), British Columbia Cancer Agency, Vancouver, BC.
authors.forename: Andrew
authors.initials: A
authors.lastname: Coldman