title: Endoscopic treatments for rectal neuroendocrine tumors smaller than 16 mm: a meta-analysis.
abstract: OBJECTIVE
  Endoscopic mucosal resection (EMR), including conventional EMR (c-EMR) and modified EMR (m-EMR), was applied to remove small rectal neuroendocrine tumors (NETs). We aim to evaluate treatment outcomes of endoscopic submucosal dissection (ESD), m-EMR and c-EMR for rectal NETs <16 mm.
  
  
  METHODS
  The PubMed, Cochrane Library and Elsevier Science Direct were searched to identify eligible articles. After quality assessment and data extraction, meta-analysis was performed. The main outcomes were complete resection rate, overall complication rate, procedure time and local recurrence rate.
  
  
  RESULTS
  Compared with c-EMR, ESD could achieve higher complete resection rate (OR = 4.38, 95%CI: 2.43-7.91, p < 0.00001) without increasing overall complication rates (OR = 2.21, 95%CI: 0.56-8.70, p = 0.25). However, ESD was more time-consuming than c-EMR (MD = 6.72, 95%CI: 5.84-7.60, p < 0.00001). Compared with m-EMR, ESD did not differ from m-EMR in complete resection and overall complication rates (OR = 0.80, 95%CI: 0.51-1.27, p = 0.34; OR = 1.91, 95%CI: 0.75-4.86, p = 0.18, respectively). However, ESD was more time-consuming than m-EMR (MD = 12.21, 95%CI: 7.78-16.64, p < 0.00001). Compared with c-EMR, m-EMR could achieve higher complete resection rate (OR = 4.23, 95%CI: 2.39-7.50, p < 0.00001) without increasing overall complication rate (OR = 1.07, 95%CI: 0.35-3.32, p = 0.90). Moreover, m-EMR was not time-consuming than c-EMR (MD = 2.01, 95%CI: -0.37-4.40, p= 0.10). The local recurrence rate was 0.84% (9/1067) during follow-up.
  
  
  CONCLUSIONS
  Both ESD and m-EMR have great advantages over c-EMR in complete resection rate without increasing safety concern while m-EMR shares similar outcomes with ESD for rectal NETs <16 mm. The results should be confirmed by well-designed, multicenter, randomized controlled trials with large samples and long-term follow-ups from more countries.
authors.affiliation: a Department of Gastroenterology , Zhongshan Hospital of Wuhan University , Wuhan City , Hubei Province , China ;|b Department of Gastroenterology , Zhongnan Hospital of Wuhan University , Wuhan City , Hubei Province , China.
authors.forename: Hai-Ping
authors.initials: HP
authors.lastname: Zhang
authors.affiliation: b Department of Gastroenterology , Zhongnan Hospital of Wuhan University , Wuhan City , Hubei Province , China.
authors.forename: Wei
authors.initials: W
authors.lastname: Wu
authors.affiliation: b Department of Gastroenterology , Zhongnan Hospital of Wuhan University , Wuhan City , Hubei Province , China.
authors.forename: Sheng
authors.initials: S
authors.lastname: Yang
authors.affiliation: a Department of Gastroenterology , Zhongshan Hospital of Wuhan University , Wuhan City , Hubei Province , China ;|b Department of Gastroenterology , Zhongnan Hospital of Wuhan University , Wuhan City , Hubei Province , China.
authors.forename: Jun
authors.initials: J
authors.lastname: Lin
mesh_terms: D004210:Dissection / Q000379:methods*; D000069916:Endoscopic Mucosal Resection / Q000379:methods*; D006801:Humans; D007413:Intestinal Mucosa / Q000473:pathology; D009364:Neoplasm Recurrence, Local / Q000473:pathology; D018358:Neuroendocrine Tumors / Q000601:surgery*; D061646:Operative Time; D011183:Postoperative Complications / Q000453:epidemiology; D012004:Rectal Neoplasms / Q000601:surgery*; D016896:Treatment Outcome
keywords: Complete resection; endoscopic mucosal resection; endoscopic submucosal dissection; overall complication rate; procedure time; rectal neuroendocrine tumors