title: Endoscopic treatment of large sessile and flat colorectal lesions.
abstract: OBJECTIVE
  With the increased number of colonoscopies performed, many polyps of different sizes and morphology are encountered today. We will reassess endoscopic treatments on large sessile and flat lesions in the colorectum.
  
  
  RESULTS
  Large lesions are considered to be greater than 2 cm in diameter with a prevalence of 0.8-5.2% in patients undergoing colonoscopy. The prevalence of malignancy in these lesions is 5-22.1%. En-bloc resection is done for lesions smaller than 2 cm in size, and piecemeal resection for those with a larger diameter. The recurrence rate was suggested to be as high as 46%. With repeated endoscopic treatments, the recurrence rate was reduced to 3.8%. Argon plasma coagulation is effective as an adjunct to piecemeal resection. It is essential to have an accurate pretreatment assessment and a proper histological evaluation of resected lesions as the prognosis depends on the depth of invasion, lymphovascular involvement, and histological type.
  
  
  CONCLUSIONS
  Endoscopic treatment for large sessile or flat lesions is highly successful in patients without the features predicting adverse outcome. Risk stratification is essential for successful outcome. With our continued efforts, improvement of endoscopic technique, and adjunctive therapy, further reduction in recurrence rate may be achieved.
authors.affiliation: Department of Gastrointestinal Medicine and Nutrition, MD Anderson Cancer Center, Houston, Texas 77002-4009, USA. nfukami@mdanderson.org
authors.forename: Norio
authors.initials: N
authors.lastname: Fukami
authors.forename: Jeffrey H
authors.initials: JH
authors.lastname: Lee
mesh_terms: D003111:Colonic Polyps / Q000473:pathology* / Q000601:surgery*; D003113:Colonoscopy / Q000379:methods; D015179:Colorectal Neoplasms / Q000473:pathology* / Q000601:surgery*; D004724:Endoscopy / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007413:Intestinal Mucosa / Q000473:pathology / Q000601:surgery; D008297:Male; D019060:Minimally Invasive Surgical Procedures; D009361:Neoplasm Invasiveness / Q000473:pathology*; D018579:Patient Selection; D018570:Risk Assessment; D016896:Treatment Outcome