title: Tests detecting biomarkers for screening of colorectal cancer: What is on the horizon?
abstract: OBJECTIVE
  To identify new and emerging screening tests for colorectal cancer (CRC) that involves detection of various biomarkers like blood, DNA and RNA in samples of faeces, tissue or blood. Current practice: Screening for CRC can be done by bowel visualisation techniques and tests that measure biomarkers. The Bowel Cancer Screening Programme (BCSP) in England uses a guaiac faecal occult blood test.
  
  
  METHODS
  The strategy was to search available literature, identify developers and contact them for relevant information. Advice from experts was sought on potential utility and likely impact of identified technologies on the BCSP.
  
  
  RESULTS
  Ninety-three companies and five research groups were contacted. Sixty-nine relevant tests were identified. Detailed information was available for 48 tests, of these 73% were CE marked and the remainder were considered as emerging. Forty-nine tests use immunochemical methods to detect occult blood in faeces. Eight, four and two tests detect biomarkers in a sample of blood, or exfoliated cells either shed in faeces or collected from rectal mucosa respectively. Six tests were grouped as 'other tests'. Most of the identified tests are performed manually and give qualitative detection of biomarkers.
  
  
  CONCLUSIONS
  Variation in test performance and characteristics was observed amongst the 69 identified tests. Automated, quantitative FIT with a variable cut off are the preferred approach in the BSCP. However the units used to report FITs results do not enable comparison across products. Tests detecting biomarkers other than occult blood are more specific to neoplasms but have limited sensitivity due to the heterogeneity of cancer. Research is ongoing to identify an optimal panel of biomarkers, simplifying and automating the test, and reducing the cost.
authors.affiliation: NIHR Horizon Scanning Research & Intelligence Centre, School of Health and Population Sciences, University of Birmingham, United Kingdom.
authors.forename: Angaja
authors.initials: A
authors.lastname: Phalguni
authors.affiliation: University of Surrey, NHS Bowel Cancer Screening Southern Programme Hub, United Kingdom.
authors.forename: Helen
authors.initials: H
authors.lastname: Seaman
authors.affiliation: NIHR Horizon Scanning Research & Intelligence Centre, School of Health and Population Sciences, University of Birmingham, United Kingdom.
authors.forename: Kristina
authors.initials: K
authors.lastname: Routh
authors.affiliation: University of Surrey, NHS Bowel Cancer Screening Southern Programme Hub, United Kingdom.
authors.forename: Stephen
authors.initials: S
authors.lastname: Halloran
authors.affiliation: NIHR Horizon Scanning Research & Intelligence Centre, School of Health and Population Sciences, University of Birmingham, United Kingdom.
authors.forename: Sue
authors.initials: S
authors.lastname: Simpson
keywords: cancer screening; cancer screening tests; colorectal cancer; colorectal carcinoma; colorectal neoplasms; colorectal tumors; early detection; early diagnosis of cancer; screening