title: Endoscopic submucosal dissection for laterally spreading tumours of the colorectum in 200 consecutive cases.
abstract: BACKGROUND
  Colorectal laterally spreading tumours (LSTs) are classified into granular (LST-G) and non-granular (LST-NG) type; each type was sub-grouped into LST-G-H (homogenous) and LST-G-M (nodular mixed) type or LST-NG-F (flat elevated) and LST-NG-FD (pseudodepressed) type, respectively. We assessed the clinicopathological factors associated with clinical outcomes of endoscopic submucosal dissection (ESD) for colorectal LSTs, and conducted follow-up after ESD.
  
  
  METHODS
  ESD was performed in 196 patients with 204 LSTs that fulfilled the inclusion criteria for colorectal neoplasms. Clinical outcomes including resectability and curability of ESD and perforation were investigated, and factors related to the outcomes were analysed using logistic regression. One hundred thirty-eight patients received endoscopic follow-up for more than 12 months and metastatic surveys in 79 cases of cancerous LSTs.
  
  
  RESULTS
  The incidence of submucosal cancer was lower in LST-G type. There were no significant differences in outcomes regarding LST macroscopic types. Overall en bloc, complete and curative resection, and perforation rates were 86.8%, 77.5%, 82.8% and 9.8%, respectively. Logistic regression analysis showed higher risk of non-curative resection in LST-G-M than in LST-G-H type. No other factors were associated with outcomes. During median follow-up of 35.5 months, no locally recurrent or metastatic tumours were observed, and overall survival was still 100%.
  
  
  CONCLUSIONS
  ESD provides acceptable resectability for colorectal LSTs by facilitating en bloc resection, irrespective of macroscopic types. The relatively long-term outcomes may be excellent, but further evaluation is needed for appropriate treatment strategy for each type of LST.
authors.affiliation: Department of Gastroenterology and Hepatology, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Nishiyama
authors.forename: Hajime
authors.initials: H
authors.lastname: Isomoto
authors.forename: Naoyuki
authors.initials: N
authors.lastname: Yamaguchi
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Ishii
authors.forename: Eiichiro
authors.initials: E
authors.lastname: Fukuda
authors.forename: Haruhisa
authors.initials: H
authors.lastname: Machida
authors.forename: Takashi
authors.initials: T
authors.lastname: Nakamura
authors.forename: Ken
authors.initials: K
authors.lastname: Ohnita
authors.forename: Saburo
authors.initials: S
authors.lastname: Shikuwa
authors.forename: Shigeru
authors.initials: S
authors.lastname: Kohno
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Nakao
mesh_terms: D000236:Adenoma / Q000473:pathology / Q000601:surgery; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002277:Carcinoma / Q000473:pathology / Q000601:surgery; D015179:Colorectal Neoplasms / Q000473:pathology / Q000601:surgery; D016099:Endoscopy, Gastrointestinal / Q000009:adverse effects; D005260:Female; D006801:Humans; D007413:Intestinal Mucosa / Q000601:surgery; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications