Molecular markers of mucosa harboring gastric adenomas.

CONTEXT: Gastric adenoma is a precursor lesion of the adenocarcinoma. OBJECTIVE: To characterize gastric adenomas according to the mucin immunoexpression and to evaluate the immunoexpression of p53, p16ink4a, BCL-2, cyclin D, Ki-67, in the adenoma and in the gastric mucosa harboring adenoma. METHODS: Forty gastric specimens from 20 patients were classified as intestinal (MUC2-goblet cell mucin) or foveolar (MUC5AC-gastric-foveolar mucin) adenomas. Immunohistochemistry was performed using streptavidin-biotin-complex method. RESULTS: Twelve (60%) patients were men. The mean age was 67.9±12.9 years-old. Intestinal adenomas were detected in 13 (65%) patients and gastric type in 7 (35%). Low-grade dysplasia was present in 13 (65%) of the adenomas, high-grade in 3 (15%), and adenocarcinoma within the polyp in 4 (20%). Six (30%) patients had synchronous adenocarcinoma. p53 immunoexpression was observed in 6/20 (30%) of adenomas, and in 2/6 (33.3%) of synchronous tumors. There was an association between p53 immunoexpression and intestinal type of adenoma/tumor, P=0.04. There was no association between p16ink4a, Bcl-2, cyclin D and Ki-67 and adenoma clinicopathological characteristics. CONCLUSION: Immunohistochemistry may be useful to classify the adenomas subtypes and may define the pathway of adenoma to carcinoma sequence.

Molecular markess of mucosa harboring gastric adenoass

Context Gastric adenoma is a precursor lesion of the adenocarcinoma. Objective To characterize gastric adenomas according to the mucin immunoexpression and to evaluate the immunoexpression of p53, p16ink4a, BCL-2, cyclin D, Ki-67, in the adenoma and in the gastric mucosa harboring adenoma. Methods Forty gastric specimens from 20 patients were classified as intestinal (MUC2 - goblet cell mucin) or foveolar (MUC5AC - gastric-foveolar mucin) adenomas. Immunohistochemistry was performed using streptavidin-biotin-complex method. Results Twelve (60%) patients were men. The mean age was 67.9 ± 12.9 years-old. Intestinal adenomas were detected in 13 (65%) patients and gastric type in 7 (35%). Low-grade dysplasia was present in 13 (65%) of the adenomas, high-grade in 3 (15%), and adenocarcinoma within the polyp in 4 (20%). Six (30%) patients had synchronous adenocarcinoma. p53 immunoexpression was observed in 6/20 (30%) of adenomas, and in 2/6 (33.3%) of synchronous tumors. There was an association between p53 immunoexpression and intestinal type of adenoma/tumor, P = 0.04. There was no association between p16ink4a, Bcl-2, cyclin D and Ki-67 and adenoma clinicopathological characteristics. Conclusion Immunohistochemistry may be useful to classify the adenomas subtypes and may define the pathway of adenoma to carcinoma sequence. .

Contexto Adenoma gástrico é uma lesão precursora do adenocarcinoma. Objetivo Melhor caracterizar os adenomas de acordo com a imunoexpressão de mucinas e avaliar a imunoexpressão de p53, p16ink4a, BCL-2, cyclin D, Ki-67, nos adenomas e na mucosa gástrica adjacente. Métodos Quarenta espécimes gástricos provenientes de 20 pacientes portadores de adenomas foram classificados como do tipo intestinal (MUC2 – mucina presente nas células caliciformes) ou gástrico (MUC5AC – mucinas de padrão foveolar). Realizou-se imunoistoquímica para p53, p16ink4a, BCL-2, cyclin D e Ki-67 pelo método do complexo da estreptavidina-biotina. Resultados Doze (60%) pacientes eram homens e a média de idade foi de 67,9 ± 12,9 anos. Os adenomas foram classificados como do tipo intestinal em 13 (65%) pacientes e do tipo gástrico em 7 (35%). Displasia (neoplasia intraepitelial) de baixo grau estava presente em 13 (65%), displasia de alto grau em 3 (15%), e adenocarcinoma no pólipo adenomatoso em 4 (20%) pacientes. Observou-se immunoexpressão do p53 em 6/20 (30%) adenomas, e em 2/6 (33,3%) dos tumores sincrônicos. Houve associação entre imunoexpressão do p53 e adenoma/tumor tipo intestinal, P = 0.04. Não houve associação entre imunoexpressão do p16ink4a, Bcl-2, ciclina D e Ki-67 e as características clinicopatológicas dos adenomas. Conclusão Imunoistoquímica pode ser utilizada para caracterizar os subtipos de adenoma e talvez indicar o caminho de carcinogênese. .