K-RAS GENE MUTATION IN GALL-BLADDER CARCINOMAS AND DYSPLASIA

Epithelial dysplasia of gall bladder is an important precancerous lesi on of gall bladder carcinogenesis. To investigate the frequency of K-r as gene mutation in gall bladder carcinoma and dysplasia, K-ras codon 12 mutations were investigated by the polymerase chain reaction/restri ction enzyme based method following direct sequencing. Mutation was de tected in 59% (30 of 51) of gall bladder carcinomas, in 73% (8 of 11) of gall bladder dysplasia in gall stone cases, and in 0% of the normal gall bladder epithelium. There was, however, no correlation between K -ras mutation and clinicopathological factors of gall bladder carcinom a. K-ras gene mutation occurs even in gall bladder dysplasia at an inc idence similar to that in carcinomas, suggesting that testing for K-ra s gene mutation may prove useful as an adjunct to bile cytological or biopsy analysis.