P53 TUMOR-SUPPRESSOR GENE PROTEIN EXPRESSION IN EARLY AND ADVANCED GALLBLADDER CARCINOMA

Aims: Gallbladder carcinoma is one of the most frequent malignant tumo urs occurring in Chile and the mortality rate in both sexes ranks amon g one of the highest in the world, Mutation of p53 tumour suppressor g ene has been demonstrated in many tumours. Our aim was to determine pr otein expression of p53 gene in early and advanced gallbladder carcino ma. Methods and results: Protein expression of gene p53 was studied by immunohistochemical means in 191 gallbladder carcinomas (157 primary tumours, 34 metastases) and 25 controls, In 86 out of 191 cases (45%), protein expression of gene p53 was observed. Differences related to s ex, age, or race were not observed, All gallbladder controls were nega tive, Twenty-five per cent: of well-differentiated tumours were p53 po sitive, while moderate or poorly differentiated carcinomas reached 50% (P = 0.04), p53 expression was observed in 23.5% of early carcinomas and in 45.2% of advanced carcinomas (P = 0.01), No differences between primary rumours and metastasis were demonstrated. Conclusions: Protei n expression of p53 tumour suppressor gene is observed in 45% of gallb ladder carcinomas, The absence of expression in controls and in normal mucosa adjacent to rumours suggests its utility in differentiating at ypical gallbladder epithelia from neoplastic lesions.