The most common alterations were TP53, KRAS, and CDKN2A in gallbladder carcinoma; TP53, KRAS, PIK3CA, and BRAF in intrahepatic cholangiocarcinoma; and TP53 and SMAD4 in extrahepatic cholangiocarcinoma.
These latest advancements along with known mutations in KRAS/BRAF/EGFR and 11q13 high-level amplification have contributed to a better understanding of the landscape of molecular alterations in iCCA.
In conclusion, we demonstrate that BRAFV600E mutation is a rare event in biliary tract cancer, accounting for only 1% of all subtypes, and is restricted to intrahepatic cholangiocarcinoma.
Therefore, testing for KRAS and BRAF mutations could be a valuable adjunct in improving both prognosis and outcome stratification among patients with intrahepatic cholangiocarcinoma.