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A case‐control study of colorectal cancer detection by quantification of DNA isolated from directly collected exfoliated colonocytes
Author(s) -
Loktionov Alexandre,
Ferrett Colin G,
Gibson Jeremy J S,
Bandaletova Tatiana,
Dion Carine,
Llewelyn Andrew H,
Lywood Hugo G G,
Lywood Rupert C G,
George Bruce D,
Mortensen Neil J
Publication year - 2009
Publication title -
international journal of cancer
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.475
H-Index - 234
eISSN - 1097-0215
pISSN - 0020-7136
DOI - 10.1002/ijc.24729
Subject(s) - colorectal cancer , medicine , gastroenterology , rectum , cancer , pathology , urology
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 μg/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 μg/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 μg/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.