Mutational analysis of BRAF in gallbladder carcinomas in association with K-ras and p53 mutations and microsatellite instability

Background. Little is known about the genetic changes involved in the pathogenesis of gallbladder cancer. The aim of this study was to examine the presence of mutations in exon 15 of the B-raf gene to investigate its role in gallbladder carcinogenesis. Materials and methods. We examined the mutational status in exon 15 of B-raf gene in 21 gallbladder carcinoma specimens and investigated its association with the presence of K-ras and p53 alterations, microsatellite instability and the clinicopathological features of tumors. Results. B-raf mutations were observed in 7 of 21 (33%) gallbladder carcinomas examined, and all were located at the hot spot codon 599 of exon 15. K-ras and B-raf mutations were never in the same specimens. Conclusions. B-raf gene mutations seem to be a quite common event in gallbladder carcinomas, implying that B-raf may play an important role in the pathogenesis of this tumor.