title: Early nonpolypoid colorectal cancer: radiographic diagnosis of depth of invasion.
abstract: OBJECTIVE
  To diagnose depth of invasion of early flat and depressed nonpolypoid colorectal cancers with double-contrast barium enema examination.
  
  
  METHODS
  Ninety-seven early nonpolypoid colorectal cancers, initially identified with colonoscopy, were investigated with double-contrast barium enema examination. Depth of invasion in resected specimens obtained with endoscopic mucosal or surgical resection was determined. Cancer confined to the mucosal layer or with focal extension to the submucosal layer was defined as Ca-m; moderate to massive extension of cancer into the submucosal layer was classified Ca-sm.
  
  
  RESULTS
  In flat elevated and depressed cancers, converging folds and semilunar deformity were observed significantly more frequently in Ca-sm than in Ca-m tumors (P < .05 and P < .01, respectively). Sensitivities and specificities of these findings for Ca-sm tumor were 42%, 93% and 86%, 85%, respectively. Deep depression, irregular surface of the depression, and tumor size larger than 20 mm were also predictive findings for depressed Ca-sm tumors (P < .05); the specificity of each was 100%. With use of these radiographic predictors, overall accuracy for diagnosing depth of invasion was 85%.
  
  
  CONCLUSIONS
  Findings on double-contrast barium enema study are highly predictive of depth of invasion of early nonpolypoid colorectal cancer. Radiographic findings of converging folds, semilunar deformity, deep depression, irregular surface of the depression, and tumor size are predictors of Ca-sm tumor.
authors.affiliation: Third Department of Internal Medicine, Asahikawa Medical College, Japan.
authors.forename: J
authors.initials: J
authors.lastname: Watari
authors.forename: Y
authors.initials: Y
authors.lastname: Saitoh
authors.forename: T
authors.initials: T
authors.lastname: Obara
authors.forename: T
authors.initials: T
authors.lastname: Fujiki
authors.forename: M
authors.initials: M
authors.lastname: Taniguchi
authors.forename: M
authors.initials: M
authors.lastname: Nomura
authors.forename: T
authors.initials: T
authors.lastname: Ayabe
authors.forename: T
authors.initials: T
authors.lastname: Ohta
authors.forename: Y
authors.initials: Y
authors.lastname: Orii
authors.forename: Y
authors.initials: Y
authors.lastname: Kohgo
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001466:Barium Sulfate; D003113:Colonoscopy; D015179:Colorectal Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D003287:Contrast Media; D004733:Enema; D005260:Female; D006801:Humans; D007413:Intestinal Mucosa / Q000473:pathology; D008297:Male; D008875:Middle Aged; D011859:Radiography; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media; D001466:Barium Sulfate