title: Building the Evidence Base of Blood-Based Biomarkers for Early Detection of Cancer: A Rapid Systematic Mapping Review.
abstract: BACKGROUND
  The Early Cancer Detection Consortium is developing a blood-test to screen the general population for early identification of cancer, and has therefore conducted a systematic mapping review to identify blood-based biomarkers that could be used for early identification of cancer.
  
  
  METHODS
  A mapping review with a systematic approach was performed to identify biomarkers and establish their state of development. Comprehensive searches of electronic databases Medline, Embase, CINAHL, the Cochrane library and Biosis were conducted in May 2014 to obtain relevant literature on blood-based biomarkers for cancer detection in humans. Screening of retrieved titles and abstracts was performed using an iterative sifting process known as "data mining". All blood based biomarkers, their relevant properties and characteristics, and their corresponding references were entered into an inclusive database for further scrutiny by the Consortium, and subsequent selection of biomarkers for rapid review. This systematic review is registered with PROSPERO (no. CRD42014010827).
  
  
  RESULTS
  The searches retrieved 19,724 records after duplicate removal. The data mining approach retrieved 3990 records (i.e. 20% of the original 19,724), which were considered for inclusion. A list of 814 potential blood-based biomarkers was generated from included studies. Clinical experts scrutinised the list to identify miss-classified and duplicate markers, also volunteering the names of biomarkers that may have been missed: no new markers were identified as a result. This resulted in a final list of 788 biomarkers.
  
  
  CONCLUSIONS
  This study is the first to systematically and comprehensively map blood biomarkers for early detection of cancer. Use of this rapid systematic mapping approach found a broad range of relevant biomarkers allowing an evidence-based approach to identification of promising biomarkers for development of a blood-based cancer screening test in the general population.
authors.affiliation: The University of Sheffield, Regent Court, 30 Regent Street, Sheffield S1 4DA, UK.
authors.forename: Lesley
authors.initials: L
authors.lastname: Uttley
authors.affiliation: Centre for Technology Enabled Health Research, Faculty of Health and Life Sciences, Coventry University, Coventry CV1 5FB, UK; Warwick Medical School, University of Warwick, Coventry CV4 7AL, UK.
authors.forename: Becky L
authors.initials: BL
authors.lastname: Whiteman
authors.affiliation: The University of Sheffield, Regent Court, 30 Regent Street, Sheffield S1 4DA, UK.
authors.forename: Helen Buckley
authors.initials: HB
authors.lastname: Woods
authors.affiliation: The University of Sheffield, Regent Court, 30 Regent Street, Sheffield S1 4DA, UK.
authors.forename: Susan
authors.initials: S
authors.lastname: Harnan
authors.affiliation: Warwick Medical School, University of Warwick, Coventry CV4 7AL, UK.
authors.forename: Sian Taylor
authors.initials: ST
authors.lastname: Philips
authors.affiliation: Centre for Technology Enabled Health Research, Faculty of Health and Life Sciences, Coventry University, Coventry CV1 5FB, UK; Department of Pathology, University Hospitals Coventry and Warwickshire, Coventry CV2 2DX, UK. Electronic address: ian.cree@uhcw.nhs.uk.
authors.forename: Ian A
authors.initials: IA
authors.lastname: Cree
mesh_terms: D014408:Biomarkers, Tumor; D019295:Computational Biology / Q000379:methods; D057225:Data Mining / Q000379:methods; D055088:Early Detection of Cancer; D019317:Evidence-Based Medicine; D006801:Humans; D009369:Neoplasms / Q000097:blood* / Q000175:diagnosis*; D057188:Workflow
chemical_list: D014408:Biomarkers, Tumor
keywords: Assay; Biomarker; Blood; Cancer; Diagnosis; Early detection; Systematic review