title: Multitarget stool DNA test: clinical performance and impact on yield and quality of colonoscopy for colorectal cancer screening.
abstract: OBJECTIVE
  Multitarget stool DNA (MT-sDNA) testing is now approved by the U.S. Food and Drug Administration for average-risk colorectal cancer screening. Trials leading to its approval used blinded colonoscopy as the reference standard. In the postapproval screen setting, the clinical performance and impact of MT-sDNA testing on unblinded colonoscopy has not been described. We measured the impact that knowledge of a positive MT-sDNA test result has on colonoscopy yield and quality.
  
  
  METHODS
  The unblinded group comprised all patients with positive MT-sDNA results on screening from September 1, 2014 to September 30, 2015 at a single tertiary center. Off-label test patients were excluded. The blinded group included all MT-sDNA-positive participants in a preapproval screening study from the same center. Detailed colonoscopy findings and withdrawal times were recorded.
  
  
  RESULTS
  There were 172 MT-sDNA-positive patients in the unblinded group and 72 in the blinded group. More total adenomatous/sessile serrated polyps (70% vs 53%, P = .013) and advanced neoplasms (28% vs 21%, P = .27) were detected in unblinded than in blinded groups. Median numbers of polyps detected were 2 (IQR, 1-4) and 1 (IQR, 0-2) in unblinded and blinded groups, respectively (P = .0007). Among polyps detected, flat or slightly raised lesions in the right side of the colon were proportionately more frequent with unblinded (40%) than with blinded examinations (9%) (P = .0017). Median withdrawal time was 19 minutes (IQR, 13-29) in the unblinded group compared with 13 minutes (IQR, 10-20) in the blinded group (P = .0001).
  
  
  CONCLUSIONS
  Knowledge of a positive MT-sDNA result appears to have a beneficial impact on the diagnostic yield and quality of subsequent colonoscopy.
authors.affiliation: Division of Gastroenterology & Hepatology, Mayo Clinic, Rochester, Minnesota, USA.
authors.forename: David H
authors.initials: DH
authors.lastname: Johnson
authors.affiliation: Division of Gastroenterology & Hepatology, Mayo Clinic, Rochester, Minnesota, USA.
authors.forename: John B
authors.initials: JB
authors.lastname: Kisiel
authors.affiliation: Division of Biomedical Statistics and Informatics, Mayo Clinic, Rochester, Minnesota, USA.
authors.forename: Kelli N
authors.initials: KN
authors.lastname: Burger
authors.affiliation: Division of Biomedical Statistics and Informatics, Mayo Clinic, Rochester, Minnesota, USA.
authors.forename: Douglas W
authors.initials: DW
authors.lastname: Mahoney
authors.affiliation: Division of Gastroenterology & Hepatology, Mayo Clinic, Rochester, Minnesota, USA.
authors.forename: Mary E
authors.initials: ME
authors.lastname: Devens
authors.affiliation: Division of Gastroenterology & Hepatology, Mayo Clinic, Rochester, Minnesota, USA.
authors.forename: David A
authors.initials: DA
authors.lastname: Ahlquist
authors.affiliation: Division of Gastroenterology & Hepatology, Mayo Clinic, Rochester, Minnesota, USA.
authors.forename: Seth
authors.initials: S
authors.lastname: Sweetser
mesh_terms: D000236:Adenoma / Q000175:diagnosis* / Q000235:genetics; D000368:Aged; D002277:Carcinoma / Q000175:diagnosis* / Q000235:genetics; D003111:Colonic Polyps / Q000175:diagnosis* / Q000235:genetics; D003113:Colonoscopy; D015179:Colorectal Neoplasms / Q000175:diagnosis* / Q000235:genetics; D004247:DNA / Q000032:analysis; D004273:DNA, Neoplasm / Q000032:analysis*; D055088:Early Detection of Cancer; D005243:Feces / Q000737:chemistry*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged
chemical_list: D004273:DNA, Neoplasm; D004247:DNA