title: Validation of a real-time PCR-based qualitative assay for the detection of methylated SEPT9 DNA in human plasma.
abstract: BACKGROUND
  Epi proColon® is a new blood-based colorectal cancer (CRC) screening test designed to determine the methylation status of a promoter region of the SEPT9 (septin 9) gene in cell-free DNA isolated from plasma. We describe the analytical and clinical performance of the test.
  
  
  METHODS
  Analytical performance at 4 testing laboratories included determination of limit of detection, precision, and reproducibility of the SEPT9 test. Clinical performance was evaluated in a prospective study by use of samples (n = 1544) from subjects enrolled in the PRESEPT clinical trial. Results were analyzed by comparison with colonoscopy, the reference standard.
  
  
  RESULTS
  The limit of detection for methylated SEPT9 DNA was 7.8 pg/mL (95% CI 6-11 pg/mL) corresponding to <2 genome copies of methylated SEPT9 per milliliter of plasma. In the prospective clinical trial, sensitivity for all stages of CRC was 68% (95% CI 53%-80%) and for stage I-III CRC, 64% (48%-77%). Adjusted specificity, on the basis of negative colonoscopy findings, was 80.0% (78%-82%).
  
  
  CONCLUSIONS
  The Epi proColon test is a simple, real-time PCR-based assay for the detection of methylated SEPT9 DNA in blood that may provide a noninvasive CRC screening alternative for people noncompliant with current CRC screening guidelines.
authors.affiliation: Molecular Pathology Laboratory Network, Maryville TN; npotter@mplnet.com.
authors.forename: Nicholas T
authors.initials: NT
authors.lastname: Potter
authors.affiliation: EA | A Quintiles Company, Durham, NC;
authors.forename: Patrick
authors.initials: P
authors.lastname: Hurban
authors.affiliation: Molecular Pathology Laboratory Network, Maryville TN;
authors.forename: Mary N
authors.initials: MN
authors.lastname: White
authors.affiliation: Molecular Pathology Laboratory Network, Maryville TN;
authors.forename: Kara D
authors.initials: KD
authors.lastname: Whitlock
authors.affiliation: Medical Sciences, Amgen, Thousand Oaks, CA;
authors.forename: Catherine E
authors.initials: CE
authors.lastname: Lofton-Day
authors.affiliation: Epigenomics AG, Berlin, Germany.
authors.forename: Reimo
authors.initials: R
authors.lastname: Tetzner
authors.affiliation: Epigenomics AG, Berlin, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Koenig
authors.affiliation: Molecular Pathology Laboratory Network, Maryville TN;
authors.forename: Neil B
authors.initials: NB
authors.lastname: Quigley
authors.affiliation: Epigenomics AG, Berlin, Germany.
authors.forename: Gunter
authors.initials: G
authors.lastname: Weiss
mesh_terms: D000368:Aged; D003110:Colonic Neoplasms / Q000175:diagnosis*; D019175:DNA Methylation; D055088:Early Detection of Cancer / Q000379:methods* / Q000592:standards; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D016133:Polymerase Chain Reaction; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D058112:Septins / Q000097:blood*
chemical_list: C474315:SEPTIN9 protein, human; D058112:Septins