Imuno-expressão da ciclo-oxigenase-2 na mucosa gástrica ectópica do esôfago cervical
Arquivos
Data
2006
Autores
Thuler, Fernanda Prata Borges Martins 
Orientadores
Ferrari, Angelo Paulo
Tipo
Tese de doutorado
Título da Revista
ISSN da Revista
Título de Volume
Resumo
Introdução: A mucosa gástrica ectópica (MGE) é considerada uma anomalia
congênita e na maioria das vezes é um achado incidental do exame endoscópico.
Até hoje, não se atribuiu nenhum significado clínico a esta entidade e são raros os
casos de adenocarcinoma descritos na literatura. Até o presente momento, não
existem dados suficientes que sustentem a indicação de biópsia seriada destas
lesões, tampouco a inclusão destes pacientes em um programa de vigilância
endoscópica. A ciclo-oxigenase-2 (COX-2) é uma proteína envolvida no
desenvolvimento de neoplasias do trato gastro-intestinal, basicamente por inibição
da apoptose e estímulo da angiogênese.
Objetivos: O objetivo principal deste estudo foi avaliar a imuno-expressão da
COX-2 na MGE e compará-la com aquela observada em biópsias de tecidos
esofágico e gástrico normais e, ainda, no esôfago de Barrett. Este estudo teve
como objetivos secundários determinar a prevalência da MGE, identificar suas
características macro e microscópicas e, avaliar sua colonização pelo Helicobacter
pylori.
Pacientes e Método: Foram avaliados prospectivamente 1327 pacientes durante o
período de agosto de 2001 a maio de 2002. Quando a MGE esteve presente,
foram realizadas biópsias da ilhota de mucosa ectópica e também do antro gástrico
para diagnóstico da infecção pelo Helicobacter pylori. Espécimes de biópsias do
esôfago distal, antro e corpo gástrico normais e, também do esôfago de Barrett
foram recuperados do banco de dados do Departamento de Patologia. Os fragmentos de MGE foram submetidos a avaliação histológica para determinar o
tipo de epitélio gástrico, presença de Helicobacter pylori e processo infamatório. O
estudo imuno-histoquímico da expressão da COX-2 foi executado pelo método da
estreptavidina-biotina-peroxidase. Este estudo foi aprovado pelo Comitê de Ética
em Pesquisa da instituição.
Resultados: A MGE foi encontrada em 14 pacientes (1,1%). O tamanho da ilhota
variou de 2 a 20 mm, as lesões eram isoladas em 10 pacientes, duas lesões em
três e três em um paciente. A avaliação histológica revelou epitélio do tipo fúndico
em 58,3% e antral/fúndico em 41,7%. A infecção pelo Helicobacter pylori esteve
presente na metade dos casos e a inflamação crônica em 66,7%. A expressão da
COX-2 foi negativa nos 10 espécimes de esôfago distal normal, 10 do antro e 10
do corpo gástrico normal. Por outro lado, a expressão da COX-2 foi positiva em
41,7% da MGE e 90% dos casos de esôfago de Barrett. A comparação entre a
expressão da COX-2 nos tecidos normais e MGE atingiu diferença significante (p =
0,04), bem como entre a MGE e o esôfago de Barrett (p = 0,03).
Conclusões: Os resultados do estudo demonstram o aumento da imunoexpressão
da COX-2 na MGE sugerindo um possível potencial de malignização
desta mucosa. Não houve correlação com nenhum achado endoscópico ou
histológico específico.
Background and Aims: Ectopic gastric mucosa is considered a congenital condition and an endoscopic incidental finding in most cases. No clinical signifance has been atributed to this entity so far and rare cases of adenocarcinoma are described in the literature. At the present moment, there isn’t enough data to sustain that this heterotopic mucosa must be biopsied, nevertheless a follow-up should be instituted. The cyclooxigenase-2 (COX-2) is a protein enrolled in the development of gastrointestinal tumors, by inhibiting apoptosis and regulating angiogenesis. The aim of this study was to evaluate by immunohistochemistry the prevalence of COX-2 expression in ectopic gastric mucosa (EGM) and correlate this expression to normal tissue samples and Barrett’s esophagus. This study also aimed to determine the inlet patch prevalence, to identify its macroscopic and histological characteristics as well as the colonization by Helicobacter pylori. Methods: We prospectevely evaluated 1327 patients to disclose the presence of EGM during the period of August 2001 and May 2002. Biopsies were taken from the pacth to histological evaluation and from the gastric antrum to disclose Helicobacter pylori infection. In addition, biopsies taken from normal esophageal mucosa, normal gastric antrum and body and Barrett’s esophagus were recovered from data bank. EGM biopsies were assessed to rule out the type of gastric epithelium, presence of Helicobacter pylori and inflammation. COX-2 was assessed by immunohistochemistry and performed in all three group samples by the avidin-biotin complex technique. This study was approved by our Institution’s Ethics Committee. Results: Heterotopic gastric patch was found in 14 patients (1,1%). Patch size ranged from 2 to 20 mm, and appeared as a single islet in 10 patients, two patchs in 3 and three in only one patient. Histological examination revealed fundic type epithelium in 58.3% and antral/fundic in 41.7%. Helicobacter pylori was present in half cases and chronic inflammation in 66.7%. Epithelial expression of COX-2 was negative in 10 normal distal esophagus, 10 normal gastric antrum and 10 normal gastric body specimens. The comparison between COX-2 expression in normal mucosa and ectopic gastric mucosa reached statistical sigificance (p = 0.04) as well as between EGM and Barrett’s esophagus (p = 0.03). COX-2 immunoexpression in EGM was unrelated to sex gender, age, epithelium type, presence of chronic inflammation or intestinal metaplasia, H. pylori infection and none of associated endoscopic findings. Conclusion: Our results demonstrate up-regulation of COX-2 in EGM, suggesting a possible malignant potential of this so-called harmless ectopic mucosa.
Background and Aims: Ectopic gastric mucosa is considered a congenital condition and an endoscopic incidental finding in most cases. No clinical signifance has been atributed to this entity so far and rare cases of adenocarcinoma are described in the literature. At the present moment, there isn’t enough data to sustain that this heterotopic mucosa must be biopsied, nevertheless a follow-up should be instituted. The cyclooxigenase-2 (COX-2) is a protein enrolled in the development of gastrointestinal tumors, by inhibiting apoptosis and regulating angiogenesis. The aim of this study was to evaluate by immunohistochemistry the prevalence of COX-2 expression in ectopic gastric mucosa (EGM) and correlate this expression to normal tissue samples and Barrett’s esophagus. This study also aimed to determine the inlet patch prevalence, to identify its macroscopic and histological characteristics as well as the colonization by Helicobacter pylori. Methods: We prospectevely evaluated 1327 patients to disclose the presence of EGM during the period of August 2001 and May 2002. Biopsies were taken from the pacth to histological evaluation and from the gastric antrum to disclose Helicobacter pylori infection. In addition, biopsies taken from normal esophageal mucosa, normal gastric antrum and body and Barrett’s esophagus were recovered from data bank. EGM biopsies were assessed to rule out the type of gastric epithelium, presence of Helicobacter pylori and inflammation. COX-2 was assessed by immunohistochemistry and performed in all three group samples by the avidin-biotin complex technique. This study was approved by our Institution’s Ethics Committee. Results: Heterotopic gastric patch was found in 14 patients (1,1%). Patch size ranged from 2 to 20 mm, and appeared as a single islet in 10 patients, two patchs in 3 and three in only one patient. Histological examination revealed fundic type epithelium in 58.3% and antral/fundic in 41.7%. Helicobacter pylori was present in half cases and chronic inflammation in 66.7%. Epithelial expression of COX-2 was negative in 10 normal distal esophagus, 10 normal gastric antrum and 10 normal gastric body specimens. The comparison between COX-2 expression in normal mucosa and ectopic gastric mucosa reached statistical sigificance (p = 0.04) as well as between EGM and Barrett’s esophagus (p = 0.03). COX-2 immunoexpression in EGM was unrelated to sex gender, age, epithelium type, presence of chronic inflammation or intestinal metaplasia, H. pylori infection and none of associated endoscopic findings. Conclusion: Our results demonstrate up-regulation of COX-2 in EGM, suggesting a possible malignant potential of this so-called harmless ectopic mucosa.
Descrição
Citação
THULER, Fernanda Prata Borges Martins. Imuno-expressão da ciclo-oxigenase-2 na mucosa gástrica ectópica do esôfago cervical. 2006.
112 f. Tese (Doutorado em Ciências) – Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, 2006