title: Diagnostic performance of EUS for evaluating the invasion depth of early colorectal cancers.
abstract: BACKGROUND
  EUS is one technique used to estimate the invasion depth of early colorectal cancer (CRC), but its diagnostic accuracy remains a matter of debate.
  
  
  OBJECTIVE
  To assess the accuracy of EUS for estimating the invasion depth of early CRC.
  
  
  METHODS
  Retrospective analysis.
  
  
  METHODS
  Tertiary-care academic medical center.
  
  
  METHODS
  The invasion depth of early CRC was estimated by EUS from 1989 through 2012.
  Accuracy of EUS diagnosis, risk factors for misdiagnosis, and characteristics of lesions that were difficult to image.
  
  
  RESULTS
  We estimated the invasion depth of 714 cases of early CRC on EUS. Of the lesions able to be visualized on EUS, the overall diagnostic accuracy of EUS for differentiating between lesions that could be resected endoscopically (Tis and T1a cancers), and those that required colectomy (T1b cancers) was 89%. Submucosal cancer and a macroscopic classification of superficial type were independent risk factors for misdiagnosis. Ninety lesions (13%) were difficult to image. Risk factors for difficulty in imaging were protruding-type morphology and tumor location in the sigmoid colon or from the descending colon to the cecum.
  
  
  CONCLUSIONS
  Single center, retrospective. Experienced endoscopists performed EUS.
  
  
  CONCLUSIONS
  Although some lesions that were protruding or located in the proximal colon were difficult to visualize, EUS is considered a useful technique for the diagnosis of invasion depth and the selection of treatment in patients with early CRC.
authors.affiliation: Department of Gastroenterology, Kitasato University, School of Medicine, Kanagawa, Japan.
authors.forename: Miyuki
authors.initials: M
authors.lastname: Mukae
authors.affiliation: Research and Development Center for New Medical Frontiers, Kitasato University, School of Medicine, Kanagawa, Japan.
authors.forename: Kiyonori
authors.initials: K
authors.lastname: Kobayashi
authors.affiliation: Department of Gastroenterology, Kitasato University, School of Medicine, Kanagawa, Japan.
authors.forename: Miwa
authors.initials: M
authors.lastname: Sada
authors.affiliation: Department of Gastroenterology, Kitasato University, School of Medicine, Kanagawa, Japan.
authors.forename: Kaoru
authors.initials: K
authors.lastname: Yokoyama
authors.affiliation: Department of Gastroenterology, Kitasato University, School of Medicine, Kanagawa, Japan.
authors.forename: Wasaburo
authors.initials: W
authors.lastname: Koizumi
authors.affiliation: Department of Pathology, Kitasato University, School of Medicine, Kanagawa, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Saegusa
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003113:Colonoscopy / Q000379:methods*; D015179:Colorectal Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology*; D003951:Diagnostic Errors; D019160:Endosonography; D005260:Female; D006801:Humans; D007413:Intestinal Mucosa / Q000000981:diagnostic imaging / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D012189:Retrospective Studies; D012680:Sensitivity and Specificity