title: Endoscopic treatment for laterally spreading tumors in the colon.
abstract: OBJECTIVE
  Laterally spreading tumors (LST) of the colon are best removed by endoscopic mucosal resection (EMR) as they extend laterally rather than vertically. Since they sometimes invade deeply into the submucosal layer, it is important to assess the depth of invasion endoscopically before treatment. In the present study, we examined the endoscopic features of a large number of LSTs in order to assess which features correlated with depth of invasion.
  
  
  METHODS
  257 LSTs removed at the National Cancer Center Hospital, Tokyo, between January 1988 and September 1998 were retrospectively analyzed.
  
  
  RESULTS
  With univariate analysis, unevenness of nodules, presence of large nodules, size, histological type, and presence of depression in the tumor were significantly associated with depth of invasion. Multivariate analysis revealed that histological type and depression in the tumor were independent factors predicting massive submucosal invasion. When an LST showed: 1) even nodules without depression, or 2) uneven nodules without depression and less than 3 mm in diameter, the risk of massive submucosal invasion was 0 % (0/121) and 3.7 % (3/82), respectively.
  
  
  CONCLUSIONS
  When LSTs meet the above endoscopic criteria, EMR should be the first-line treatment because of the low risk of massive submucosal invasion.
authors.affiliation: Dept. of Gastrointestinal Endoscopy, National Cancer Center Hospital, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104, Japan. ytsaito@gan2.ncc.go.jp
authors.forename: Y
authors.initials: Y
authors.lastname: Saito
authors.forename: T
authors.initials: T
authors.lastname: Fujii
authors.forename: H
authors.initials: H
authors.lastname: Kondo
authors.forename: H
authors.initials: H
authors.lastname: Mukai
authors.forename: T
authors.initials: T
authors.lastname: Yokota
authors.forename: T
authors.initials: T
authors.lastname: Kozu
authors.forename: D
authors.initials: D
authors.lastname: Saito
mesh_terms: D000230:Adenocarcinoma / Q000473:pathology / Q000601:surgery*; D000236:Adenoma / Q000473:pathology / Q000601:surgery*; D000368:Aged; D000704:Analysis of Variance; D015179:Colorectal Neoplasms / Q000473:pathology* / Q000601:surgery*; D016145:Endoscopy, Digestive System; D005260:Female; D006801:Humans; D007413:Intestinal Mucosa / Q000473:pathology / Q000601:surgery; D008297:Male; D009361:Neoplasm Invasiveness; D018579:Patient Selection; D012044:Regression Analysis; D012189:Retrospective Studies