title: Importance of proliferation markers in gastrointestinal carcinoid tumors: a clinicopathologic study.
abstract: OBJECTIVE
  Carcinoid tumors are common tumors in the gastrointestinal tract. Certain criteria such as the depth of invasion, the localization, the tumor size, the mitotic index and the pattern of ploidy are used to determine the potential biological behavior of these tumors some of which might be malignant. The goal of this study was to assess the prognostic significance of proliferation markers (Ki67 and PCNA) in carcinoid tumors by using immunohistochemistry.
  
  
  METHODS
  An immunostaining in 37 carcinoid tumors arising in various locations of the gastrointestinal tract was performed. The best stained area was selected and 1000 neoplastic cells were counted in order to determine the proliferation index in each case.
  
  
  RESULTS
  The results of proliferation index were compared with the depth of invasion, the embryologic type, the tumor size, the presence of metastases and disease-free survival by using statistical methods. The Ki67 tumor proliferation index in the tumors > 2.1 cm was significantly different from the tumors < or = 2 cm (P = 0.032).
  
  
  CONCLUSIONS
  The presence of significant correlation between Ki67 positivity and the tumor size might suggest that Ki67 antibody can be useful for the determination of potential behavior of gastrointestinal carcinoid tumors.
authors.affiliation: Department of Pathology, Medical Faculty of Hacettepe University, Ankara 06100, Turkey. sokmensuer@superonline.com
authors.forename: C
authors.initials: C
authors.lastname: Sökmensüer
authors.forename: G
authors.initials: G
authors.lastname: Gedikoglu
authors.forename: B
authors.initials: B
authors.lastname: Uzunalimoglu
mesh_terms: D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000032:analysis*; D002276:Carcinoid Tumor / Q000473:pathology*; D002455:Cell Division / Q000502:physiology*; D004064:Digestive System / Q000473:pathology; D005260:Female; D005770:Gastrointestinal Neoplasms / Q000473:pathology*; D006801:Humans; D019394:Ki-67 Antigen / Q000032:analysis*; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D011379:Prognosis; D018809:Proliferating Cell Nuclear Antigen / Q000032:analysis*
chemical_list: D014408:Biomarkers, Tumor; D019394:Ki-67 Antigen; D018809:Proliferating Cell Nuclear Antigen