title: p21 and p27 immunoexpression in gastric well differentiated endocrine tumors (ECL-cell carcinoids).
abstract: OBJECTIVE
  To investigate the expression of cyclin-dependent kinase inhibitors p21 and p27 in gastric well differentiated endocrine tumors (GWDET) (ECL-cell carcinoids).
  
  
  METHODS
  The expressions of p21 and p27 were examined immunhistochemically in endoscopic biopsy specimens from 16 patients matching the diagnostic criteria of GWDET. Percentage of positive nuclear staining either weak or strong was noted. The association of immunoexpressions with age, gender, tumor localization, multifocality and accompanying chronic atrophic gastritis, neuroendocrine cell hyperplasia (NEH), neuroendocrine dysplasia (NED), intestinal metaplasia (IM), Ki-67 proliferation index and clinical outcome were also evaluated.
  
  
  RESULTS
  All cases expressed p27 with a mean expression score of 43.6%, while 31.3% of the cases showed any p21 expression. p21 and p27 immunoexpressions were significantly correlated with each other (P < 0.01), and the p21-expressing group had higher p27 expression scores (68% vs 22%). p21 and p27 expressions were lower in women, in non-atrophic mucosa and cases whose tumors were located somewhere other than fundus without submucosal extension. On contrary, p21 and p27 expressions were higher in males and the patients with submucosal extension and atrophic gastritis. Cases presenting lower p27 scores had solitary tumors showing neither NEH-NED nor IM. Despite, cases with lower p21 expression presented multifocal tumors accompanied by NEH-NED. However, no correlation of p21 and p27 expressions was found with age and Ki-67 expression.
  
  
  CONCLUSIONS
  p27 is widely expressed in GWDETs, while p21 expression is sparse and observed in two thirds of the cases. Loss of p21 and p27 expressions may be correlated with different carcinoid tumor subtypes; however, more studies are needed to assess the role of these prospective markers in gastrointestinal endocrine tumors.
authors.affiliation: Ege University Faculty of Medicine, Department of Pathology, Bornova-Izmir 35100, Turkey. bdoganavsargil@yahoo.com
authors.forename: Basak
authors.initials: B
authors.lastname: Doganavsargil
authors.forename: Banu
authors.initials: B
authors.lastname: Sarsik
authors.forename: Fatma Secil
authors.initials: FS
authors.lastname: Kirdok
authors.forename: Ahmet
authors.initials: A
authors.lastname: Musoglu
authors.forename: Muge
authors.initials: M
authors.lastname: Tuncyurek
mesh_terms: D000328:Adult; D000368:Aged; D002276:Carcinoid Tumor / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000235:genetics / Q000378:metabolism*; D050760:Cyclin-Dependent Kinase Inhibitor p27 / Q000235:genetics / Q000378:metabolism*; D004701:Endocrine Gland Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D019861:Enterochromaffin-like Cells / Q000378:metabolism* / Q000473:pathology; D005260:Female; D005753:Gastric Mucosa / Q000378:metabolism / Q000473:pathology; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D006965:Hyperplasia / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D008297:Male; D008679:Metaplasia / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D008875:Middle Aged; D013274:Stomach Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology
chemical_list: D050759:Cyclin-Dependent Kinase Inhibitor p21; D050760:Cyclin-Dependent Kinase Inhibitor p27