title: Biomarkers for early detection of colorectal cancer and polyps: systematic review.
abstract: There is growing interest in early detection of colorectal cancer as current screening modalities lack compliance and specificity. This study systematically reviewed the literature to identify biomarkers for early detection of colorectal cancer and polyps. Literature searches were conducted for relevant papers since 2007. Human studies reporting on early detection of colorectal cancer and polyps using biomarkers were included. Methodologic quality was evaluated, and sensitivity, specificity, and the positive predictive value (PPV) were reported. The search strategy identified 3,348 abstracts. A total of 44 papers, examining 67 different tumor markers, were included. Overall sensitivities for colorectal cancer detection by fecal DNA markers ranged from 53% to 87%. Combining fecal DNA markers increased the sensitivity of colorectal cancer and adenoma detection. Canine scent detection had a sensitivity of detecting colorectal cancer of 99% and specificity of 97%. The PPV of immunochemical fecal occult blood test (iFOBT) is 1.26%, compared with 0.31% for the current screening method of guaiac fecal occult blood test (gFOBT). A panel of serum protein biomarkers provides a sensitivity and specificity above 85% for all stages of colorectal cancer, and a PPV of 0.72%. Combinations of fecal and serum biomarkers produce higher sensitivities, specificities, and PPVs for early detection of colorectal cancer and adenomas. Further research is required to validate these biomarkers in a well-structured population-based study.
authors.affiliation: Yeovil District Hospital NHS Trust, Yeovil, United Kingdom. Reena.shah@doctors.org.uk.
authors.forename: Reena
authors.initials: R
authors.lastname: Shah
authors.affiliation: University of Leicester, Leicester, United Kingdom.
authors.forename: Emma
authors.initials: E
authors.lastname: Jones
authors.affiliation: University of Bristol, Bristol, United Kingdom.
authors.forename: Victoire
authors.initials: V
authors.lastname: Vidart
authors.affiliation: Department of Surgery, Leiden University Medical Centre, Leiden, the Netherlands.
authors.forename: Peter J K
authors.initials: PJ
authors.lastname: Kuppen
authors.affiliation: Portsmouth Hospital NHS Trust, Portsmouth, United Kingdom. University of Southampton, Southampton, United Kingdom.
authors.forename: John A
authors.initials: JA
authors.lastname: Conti
authors.affiliation: Yeovil District Hospital NHS Trust, Yeovil, United Kingdom. University of Bristol, Bristol, United Kingdom.
authors.forename: Nader K
authors.initials: NK
authors.lastname: Francis
mesh_terms: D000818:Animals; D014408:Biomarkers, Tumor / Q000097:blood*; D003111:Colonic Polyps / Q000097:blood* / Q000175:diagnosis*; D015179:Colorectal Neoplasms / Q000097:blood* / Q000175:diagnosis*; D004285:Dogs; D055088:Early Detection of Cancer; D006801:Humans; D009780:Occult Blood
chemical_list: D014408:Biomarkers, Tumor