A case-control study of colorectal cancer detection by quantification of DNA isolated from directly collected exfoliated colonocytes.
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.
Loktionov
Alexandre
A
Colonix Medical Ltd, Cambridge, United Kingdom.
Ferrett
Colin G
CG
John Radcliffe Hospital, Oxford, United Kingdom.
Gibson
Jeremy J S
JJS
Honiton Hospital, Honiton, United Kingdom.
Bandaletova
Tatiana
T
Colonix Medical Ltd, Cambridge, United Kingdom.
Dion
Carine
C
Colonix Medical Ltd, Cambridge, United Kingdom.
Llewelyn
Andrew H
AH
Colonix Medical Ltd, Cambridge, United Kingdom.
Lywood
Hugo G G
HGG
Colonix Medical Ltd, Cambridge, United Kingdom.
Lywood
Rupert C G
RCG
Colonix Medical Ltd, Cambridge, United Kingdom.
George
Bruce D
BD
John Radcliffe Hospital, Oxford, United Kingdom.
Mortensen
Neil J
NJ
John Radcliffe Hospital, Oxford, United Kingdom.
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
D004273:DNA, Neoplasm