ALTERACIONES GENETICAS EN LESIONES PRENEOPLASICAS Y NEOPLASICAS DE LA VESICULA BILIAR

Resumen

In Chile, the gallbladder cancer is the main cause of death for women older than 40 years. However, there is almost none information about the morphological changes and the genetic alterations involved in its begining and development.

Two carcinogenics ways have been described. The sequence adenoma-carcinoma is accepted to be less frequent and important. The most important is the sequence where the metaplasia evolves to displasia wich progress to carcinoma in situ and finally it becomes invasive. This progress requires 10 to 15 years approximately. During this time, a continue progression of injuries have been described.

Molecular research studies show genetic anomalies in some genes which are temporary events in preneoplastics injuries of gallbladder. Some of them even exist before the first morphological changes, while the expression of tumor suppressors genes like p53, adhesion molecules and oncogenes, among others, can be related to late GB carcinogenesis. The K-ras gene seems to play a role in this neoplasia, specially in those that present an anormal biliopancreatics union. The microsatelital inestability has been found in a small subset of preneoplastic an neoplastic lesions. The existence of methylation in the promotors gene areas has been related to the cellular proliferation, invasion and metastasis and also in cases of chronic cholecystitis, suggesting that this epigenetic phenomenon represents an early event crucial in GB carcinogenesis.