title: Over-expression of cyclooxygenase-2 in endoscopic biopsies of ectopic gastric mucosa.
abstract: Ectopic gastric mucosa (EGM) is considered to be a congenital condition. Rare cases of adenocarcinoma have been described. There are no data justifying regular biopsies or follow-up. Cyclooxygenase-2 (COX-2) is a protein involved in gastrointestinal tumor development by inhibiting apoptosis and regulating angiogenesis. The aim of this prospective study was to evaluate COX-2 expression in EGM and compare it with normal tissue and Barrett's esophagus. We evaluated 1327 patients. Biopsies were taken from the inlet patch for histological evaluation and from the gastric antrum to assess Helicobacter pylori infection. Biopsies taken from normal esophageal, gastric antrum and body mucosa and Barrett's esophagus were retrieved from a tissue bank. EGM biopsies were evaluated with respect to type of epithelium, presence of H. pylori, and inflammation. COX-2 was detected by immunohistochemistry using the avidin-biotin complex. EGM islets were found in 14 patients (1.1%). Histological examination revealed fundic type epithelium in 58.3% of cases, H. pylori was present in 50% and chronic inflammation in 66.7%. Expression of COX-2 was negative in normal distal esophagus, normal gastric antrum and normal gastric body specimens (10 each). In contrast, EGM presented over-expression of COX-2 in 41.7% of cases and Barrett's esophagus in 90% of cases (P = 0.04 and 0.03, respectively). COX-2 immunoexpression in EGM was not related to gender, age, epithelium type, presence of inflammation or intestinal metaplasia, H. pylori infection, or any endoscopic finding. Our results demonstrate up-regulation of COX-2 in EGM, suggesting a possible malignant potential of this so-called harmless mucosa.
authors.affiliation: Disciplina de Gastroenterologia, Escola Paulista de Medicina, Universidade Federal de São PauloSão Paulo, SP, Brasil. fernandaprata@terra.com.br
authors.forename: F P
authors.initials: FP
authors.lastname: Martins
authors.forename: R
authors.initials: R
authors.lastname: Artigiani Neto
authors.forename: C T
authors.initials: CT
authors.lastname: Oshima
authors.forename: P P da
authors.initials: PP
authors.lastname: Costa
authors.forename: Forones
authors.initials: F
authors.lastname: N M
authors.forename: A P
authors.initials: AP
authors.lastname: Ferrari
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001471:Barrett Esophagus / Q000201:enzymology / Q000473:pathology; D001706:Biopsy; D002828:Choristoma / Q000201:enzymology* / Q000473:pathology; D051546:Cyclooxygenase 2 / Q000378:metabolism*; D004935:Esophageal Diseases / Q000201:enzymology* / Q000473:pathology; D005260:Female; D005753:Gastric Mucosa / Q000201:enzymology* / Q000473:pathology; D016480:Helicobacter pylori / Q000302:isolation & purification; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011706:Pyloric Antrum / Q000201:enzymology* / Q000382:microbiology / Q000473:pathology
chemical_list: D051546:Cyclooxygenase 2