Correlation of p53 protein expression with gene mutation in gall-bladder carcinomas

The correlation of p53 protein expression and p53 mutation of 33 gall-bladder carclnomas was studied accordlng to the depth of invasion and grade of cytological atypia. Overexpresslon of p53 protein was detected by immunostaining in seven (70.00/) of 10 intramucosal and in 16 (69.6%) of 23 invasive carcinomas. p53 mutation was detected in five (71.4%) of the seven intramucosal carcinomas with overexpresslon and In eight (50.0%) of the 16 invasive cancers with overexpression and in one (10%) of the 10 non-overexpressing carclnomas at exons 5–8 by nested polymerase chain reactlon-single-strand conformatlon polymorphism. The overexpression of p53 protein was present In nine (56.3%) of 16 low-grade carcinomas and In 14 (82.3%) of 17 high-grade carcinomas. In cases of overexpresslon, p53 mutatlon was detectable in four (44.4%) of nlne lowgrade and in nlne (64.3%) of 14 high-grade carclnomas. In total, p53 mutation was verified In 56.5%0 (13123) of cases involving protein overexpression and in 10% (1/10) of cases of nonoverexpresslon. The sensltivity of p53 mutation was 56.5% (13/23), the specificity was 90.0% (9/10) and the validity was 1.47. in conclusion, our study indicates that p53 protein overexpression correlates well wlth gene mutatlon and that p53 alteration may be related to increaslng grade of cytologic atypla of carclnomas.