title: Cyclooxygenase-2 expression in gastroenteropancreatic neuroendocrine tumors.
abstract: OBJECTIVE
  The aim of this multicenter study was to investigate cyclooxygenase-2 protein expression in gastroenteropancreatic neuroendocrine tumors and to examine the relationship to various clinicopathological parameters.
  
  
  METHODS
  Thirty-seven gastroenteropancreatic neuroendocrine tumor specimens were analyzed immunohistochemically. Correlations between expression and some parameters such as age, sex, tumor size, location, presence of multiple neuroendocrine tumor, lymphatic/vascular/muscularis propria invasion and lymph node metastases were evaluated. Results were interpreted as significant if p < 0.05.
  
  
  RESULTS
  Mean age of patients (15 men/22 women) was 52 +/- 17. Tumor size varied between 0.1 and 12 cm. (mean; 3.17 +/- 3.29 cm). Expression was detected in 75% of cases and in 92% of gastric neuroendocrine tumors. Expression in mixed endocrine and non-endocrine carcinomas was found to be significantly higher than in well-differentiated neuroendocrine tumors and carcinomas (p = 0.016). A relationship was observed between overexpression and lymphatic and vascular invasion (p = 0.029). However, no significant correlation was found between expression and sex, tumor location, size, muscularis propria invasion and lymph node metastasis.
  
  
  CONCLUSIONS
  Cyclooxygenase-2 expression may play a role in the evolution of gastroenteropancreatic neuroendocrine tumors. However, further studies are necessary to determine the importance of this role, prognostic relevance and whether cyclooxygenase isoenzyme can be a target for treatment in these tumors.
authors.affiliation: Gastroenterohepatology Clinic, Haydarpasa Numune Education and Research Hospital, Istanbul. alince@superonline.com
authors.forename: Ali Tüzün
authors.initials: AT
authors.lastname: Ince
authors.forename: Oya
authors.initials: O
authors.lastname: Ovünç
authors.forename: Cigdem Ataizi
authors.initials: CA
authors.lastname: Celikel
authors.forename: Süha
authors.initials: S
authors.lastname: Göksel
authors.forename: Serkan
authors.initials: S
authors.lastname: Tosun
authors.forename: Onder
authors.initials: O
authors.lastname: Peker
mesh_terms: D014408:Biomarkers, Tumor / Q000032:analysis*; D051546:Cyclooxygenase 2 / Q000032:analysis*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008565:Membrane Proteins / Q000032:analysis*; D008875:Middle Aged; D018358:Neuroendocrine Tumors / Q000175:diagnosis* / Q000201:enzymology / Q000473:pathology; D010190:Pancreatic Neoplasms / Q000175:diagnosis* / Q000201:enzymology / Q000473:pathology; D013274:Stomach Neoplasms / Q000175:diagnosis* / Q000201:enzymology / Q000473:pathology
chemical_list: D014408:Biomarkers, Tumor; D008565:Membrane Proteins; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human