title: Impact of endoscopic submucosal dissection for the therapeutic strategy of large colorectal tumors.
abstract: OBJECTIVE
  The change of therapeutic strategy for large colorectal tumors after the introduction of endoscopic submucosal dissection (ESD) has not yet been clarified. The aim of this study was to estimate the impact of ESD as an initial treatment strategy.
  
  
  METHODS
  A questionnaire was administered to nine expert panelists in colorectal ESD. The questionnaire used retrospective data from consecutive case series. Forty-seven cases of early colorectal tumors (≥ 20 mm) were included. Endoscopic growth types were 25 laterally-spreading tumors (LST) of granular type (G), 15 LST of non-granular types (NG), and seven protruded types. Pathological diagnoses included 15 adenomas (Ad), 18 intramucosal cancers (M), three submucosally-shallow invasive cancers (< 1000 µm) (SMs), and 11 submucosally-deep invasive cancers (≥ 1000 µm) (SMd). The expert panelists completed questionnaires about recommended initial treatment under suppositions of before and after the introduction of ESD. Over-surgery was defined as surgery for Ad, M, and SMs. Non-curative endoscopic resection (ER) was defined as ER for SMd.
  
  
  RESULTS
  After the introduction of ESD, the reduction in the over-surgery rate was estimated at 10.8% for Ad, M, and SMs, and the increase in the non-curative ER rate was estimated at 27.2% for SMd. By endoscopic growth type, the reduction of over-surgery rates for LST-NG, LST-G, and protruded type was 15.5%, 10.5%, and 2.2%, respectively.
  
  
  CONCLUSIONS
  The endoscopists changed their therapeutic strategy for large colorectal tumors to reduce over-surgery, especially in LST-NG, demonstrating the impact of ESD.
authors.affiliation: Department of Gastroenterology, Saku Central Hospital, Saku, Japan. k.hotta@scchr.jp
authors.forename: Kinichi
authors.initials: K
authors.lastname: Hotta
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Saito
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Fujishiro
authors.forename: Hisatomo
authors.initials: H
authors.lastname: Ikehara
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Ikematsu
authors.forename: Nozomu
authors.initials: N
authors.lastname: Kobayashi
authors.forename: Naoto
authors.initials: N
authors.lastname: Sakamoto
authors.forename: Yoji
authors.initials: Y
authors.lastname: Takeuchi
authors.forename: Toshio
authors.initials: T
authors.lastname: Uraoka
authors.forename: Yuichiro
authors.initials: Y
authors.lastname: Yamaguchi
mesh_terms: D000236:Adenoma / Q000601:surgery*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003082:Colectomy / Q000706:statistics & numerical data*; D015179:Colorectal Neoplasms / Q000473:pathology* / Q000601:surgery*; D004210:Dissection / Q000706:statistics & numerical data*; D016099:Endoscopy, Gastrointestinal; D005260:Female; D006801:Humans; D007413:Intestinal Mucosa / Q000601:surgery*; D010535:Laparoscopy / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D011795:Surveys and Questionnaires