title: A case-control study of colorectal cancer detection by quantification of DNA isolated from directly collected exfoliated colonocytes.
abstract: This pilot study aimed to assess an original test based on the analysis of exfoliated colonocytes as a new approach to colorectal cancer (CRC) detection. DNA was isolated from exfoliated cells collected from the surface of the rectal mucosa by a standardized minimally invasive procedure in a case-control trial involving 66 patients with CRC diagnosis and 110 healthy volunteers (age 50-70). PicoGreen staining and quantitative real-time PCR (QRTPCR) were used for DNA quantification. Mean DNA scores in microg/ml obtained for the control and cancer groups were 2.1 (95% CI 1.7-2.5) and 9.0 (CI 6.7-11.2) respectively (p < 0.001) for PicoGreen and 0.8 (CI 0.6-0.9) and 3.8 (CI 1.9-5.7) respectively (p = 0.003) for QRTPCR. The PicoGreen assay better detected CRC presence. At DNA score cut-off point of 2.5 microg/ml this assay gave sensitivities of 77.8% (CI 52.4-93.6) for proximal tumours, 91.4% (CI 76.9-98.2) for distal CRC and 86.8% (CI 74.7-94.5) for all CRC with specificity at 74.0% (CI 64.0-82.4). Increasing the cut-off point to 5.0 microg/ml resulted in sensitivities of 38.9% (CI 17.3-64.3) for proximal tumours, 71.4% (CI 53.7-85.4) for distal CRC and 60.4% (CI 46.0-73.5) for all CRC. Specificity for this cut-off point increased to 94.8% (CI 88.3-98.3). The new procedure of exfoliated cell collection from the surface of the rectal mucosa is a simple, safe and well-tolerated technique providing high quality cells. These early results suggest that exfoliated cell collection in combination with DNA quantification can potentially be employed as a tool for CRC early detection.
authors: Colonix Medical Ltd, Cambridge, United Kingdom.
authors: Alexandre
authors: A
authors: Loktionov
authors: John Radcliffe Hospital, Oxford, United Kingdom.
authors: Colin G
authors: CG
authors: Ferrett
authors: Honiton Hospital, Honiton, United Kingdom.
authors: Jeremy J S
authors: JJS
authors: Gibson
authors: Colonix Medical Ltd, Cambridge, United Kingdom.
authors: Tatiana
authors: T
authors: Bandaletova
authors: Colonix Medical Ltd, Cambridge, United Kingdom.
authors: Carine
authors: C
authors: Dion
authors: Colonix Medical Ltd, Cambridge, United Kingdom.
authors: Andrew H
authors: AH
authors: Llewelyn
authors: Colonix Medical Ltd, Cambridge, United Kingdom.
authors: Hugo G G
authors: HGG
authors: Lywood
authors: Colonix Medical Ltd, Cambridge, United Kingdom.
authors: Rupert C G
authors: RCG
authors: Lywood
authors: John Radcliffe Hospital, Oxford, United Kingdom.
authors: Bruce D
authors: BD
authors: George
authors: John Radcliffe Hospital, Oxford, United Kingdom.
authors: Neil J
authors: NJ
authors: Mortensen
mesh_terms: D000368:Aged; D016022:Case-Control Studies; D015179:Colorectal Neoplasms / Q000175:diagnosis* / Q000235:genetics*; D003581:Cytodiagnosis / Q000379:methods*; D004273:DNA, Neoplasm / Q000032:analysis*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D012372:ROC Curve; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012680:Sensitivity and Specificity
chemical_list: D004273:DNA, Neoplasm