title: Clinical impact of atypical endoscopic features in rectal neuroendocrine tumors.
abstract: OBJECTIVE
  To validate the association between atypical endoscopic features and lymph node metastasis (LNM).
  
  
  METHODS
  A total of 247 patients with rectal neuroendocrine tumors (NETs) were analyzed. Endoscopic images were reviewed independently by two endoscopists, each of whom classified tumors by sized and endoscopic features, such as shape, color, and surface change (kappa coefficient 0.76 for inter-observer agreement). All of patients underwent computed tomography scans of abdomen and pelvis for evaluation of LNM. Univariate and multivariate analyses were performed to identify the factors associated with LNM. Additionally, the association between endoscopic atypical features and immunohistochemical staining of tumors was analyzed.
  
  
  RESULTS
  Of 247 patients, 156 (63.2%) were male and 15 (6.1%) were showed positive for LNM. On univariate analysis, tumor size (P < 0.001), shape (P < 0.001), color (P < 0.001) and surface changes (P < 0.001) were significantly associated with LNM. On multivariate analysis, tumor size (OR = 11.53, 95%CI: 2.51-52.93, P = 0.002) and atypical surface (OR = 27.44, 95%CI: 5.96-126.34, P < 0.001) changes were independent risk factors for LNM. The likelihood of atypical endoscopic features increased as tumor size increased. Atypical endoscopic features were associated with LNM in rectal NETs < 10 mm (P = 0.005) and 10-19 mm (P = 0.041) in diameter. Immunohistochemical staining showed that the rate of atypical endoscopic features was higher in non L-cell tumors.
  
  
  CONCLUSIONS
  Atypical endoscopic features as well as tumor size are predictive factors of LNM in patients with rectal NETs.
authors.affiliation: Jong Hee Hyun, Hee Jin Chang, Dae Kyung Sohn, Center for Colorectal Cancer, National Cancer Center, Gyeonggi-do 10408, South Korea.
authors.forename: Jong Hee
authors.initials: JH
authors.lastname: Hyun
authors.affiliation: Jong Hee Hyun, Hee Jin Chang, Dae Kyung Sohn, Center for Colorectal Cancer, National Cancer Center, Gyeonggi-do 10408, South Korea.
authors.forename: Seong Dae
authors.initials: SD
authors.lastname: Lee
authors.affiliation: Jong Hee Hyun, Hee Jin Chang, Dae Kyung Sohn, Center for Colorectal Cancer, National Cancer Center, Gyeonggi-do 10408, South Korea.
authors.forename: Eui Gon
authors.initials: EG
authors.lastname: Youk
authors.affiliation: Jong Hee Hyun, Hee Jin Chang, Dae Kyung Sohn, Center for Colorectal Cancer, National Cancer Center, Gyeonggi-do 10408, South Korea.
authors.forename: Jae Bum
authors.initials: JB
authors.lastname: Lee
authors.affiliation: Jong Hee Hyun, Hee Jin Chang, Dae Kyung Sohn, Center for Colorectal Cancer, National Cancer Center, Gyeonggi-do 10408, South Korea.
authors.forename: Enu-Jung
authors.initials: EJ
authors.lastname: Lee
authors.affiliation: Jong Hee Hyun, Hee Jin Chang, Dae Kyung Sohn, Center for Colorectal Cancer, National Cancer Center, Gyeonggi-do 10408, South Korea.
authors.forename: Hee Jin
authors.initials: HJ
authors.lastname: Chang
authors.affiliation: Jong Hee Hyun, Hee Jin Chang, Dae Kyung Sohn, Center for Colorectal Cancer, National Cancer Center, Gyeonggi-do 10408, South Korea.
authors.forename: Dae Kyung
authors.initials: DK
authors.lastname: Sohn
mesh_terms: D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000032:analysis; D003113:Colonoscopy; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D018358:Neuroendocrine Tumors / Q000737:chemistry / Q000556:secondary* / Q000601:surgery; D016017:Odds Ratio; D011237:Predictive Value of Tests; D012004:Rectal Neoplasms / Q000737:chemistry / Q000473:pathology* / Q000601:surgery; D012189:Retrospective Studies; D012307:Risk Factors; D014057:Tomography, X-Ray Computed; D047368:Tumor Burden; D014741:Video Recording
chemical_list: D014408:Biomarkers, Tumor
keywords: Colonoscopy; Lymph node metastasis; Rectal neuroendocrine tumor