title: Clinical outcomes of rectal neuroendocrine tumors ≤ 10 mm following endoscopic resection.
abstract: OBJECTIVE
  This study was conducted to determine the clinical outcome of rectal neuroendocrine tumors (NETs)≤ 10 mm following conventional endoscopic resection.
  
  
  METHODS
  A total of 107 patients who underwent conventional endoscopic treatment for rectal NETs (median size 5.0 mm [range 1.0-10.0]) were followed up for a median of 31 months (range 13-121). The following data were analyzed: lesion characteristics, clinical outcomes, and histological features determined using tissue microarray analysis (TMA), including the mitotic count and the Ki-67 index.
  
  
  RESULTS
  En bloc removal was achieved for all tumors, and the complete resection rate was 49.5% (53/107). Resection margin status was indeterminate in 37 patients (34.6%) and positive in 17 (15.9%). Rectal NETs in 71 patients demonstrated a score of ≤2 % on the Ki-67 index and<2 for mitotic count on TMA. In another 28 tumors that did not undergo TMA, the mitotic count was 0-1 per 10 high-power fields. Neither recurrence nor metastasis was noted during the follow-up period following resection.
  
  
  CONCLUSIONS
  Rectal NETs (≤10 mm in size) appear to demonstrate benign behavior based on the mitotic count and the Ki-67 index. These results suggest that the outcome of rectal NETs (≤10 mm in size) following conventional endoscopic resection might be comparatively excellent, regardless of the resection margin status. However, long term follow-up data are required to confirm this.
authors.affiliation: Department of Gastroenterology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea.
authors.forename: Gwang-Un
authors.initials: GU
authors.lastname: Kim
authors.forename: Kyung-Jo
authors.initials: KJ
authors.lastname: Kim
authors.forename: Seung-Mo
authors.initials: SM
authors.lastname: Hong
authors.forename: Eun-Sil
authors.initials: ES
authors.lastname: Yu
authors.forename: Dong-Hoon
authors.initials: DH
authors.lastname: Yang
authors.forename: Kee Wook
authors.initials: KW
authors.lastname: Jung
authors.forename: Byong Duk
authors.initials: BD
authors.lastname: Ye
authors.forename: Jeong-Sik
authors.initials: JS
authors.lastname: Byeon
authors.forename: Seung-Jae
authors.initials: SJ
authors.lastname: Myung
authors.forename: Suk-Kyun
authors.initials: SK
authors.lastname: Yang
authors.forename: Jin-Ho
authors.initials: JH
authors.lastname: Kim
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D019394:Ki-67 Antigen / Q000032:analysis; D008297:Male; D008875:Middle Aged; D008940:Mitotic Index; D060787:Neoplasm Grading; D009364:Neoplasm Recurrence, Local / Q000473:pathology*; D018365:Neoplasm, Residual; D018358:Neuroendocrine Tumors / Q000737:chemistry / Q000473:pathology* / Q000601:surgery*; D012004:Rectal Neoplasms / Q000737:chemistry / Q000473:pathology* / Q000601:surgery*; D012189:Retrospective Studies; D012812:Sigmoidoscopy; D046888:Tissue Array Analysis; D016896:Treatment Outcome; D047368:Tumor Burden
chemical_list: D019394:Ki-67 Antigen