Role of genomics in intrahepatic cholangiocarcinoma for liver-directed therapy

Only a minority of patients with intrahepatic cholangiocarcinoma are candidates for curative resection. Even those with disease limited to the liver may not be surgical candidates due to patient, liver, and tumor factors, including comorbidities, intrinsic liver disease, inability to establish a future liver remnant, and tumor multifocality. In addition, even after surgery, recurrence rates are high, with the liver being a predominant site of relapse. Lastly, tumor progression in the liver can sometimes result in demise for those with advanced disease. Therefore, it is not surprising that non-surgical, liver-directed therapies have emerged as both primary and complementary treatments for intrahepatic cholangiocarcinoma for multiple stages. Liver-directed therapies can be performed directly into the tumor via thermal or non-thermal ablation, catheter-based infusion into the hepatic artery containing either cytotoxic chemotherapy or radioisotope bearing spheres/beads, or delivered via external beam radiation. Presently, these therapies' selection criteria have been based on tumor size, location, liver function, and referral to particular specialists. In recent years, molecular profiling of intrahepatic cholangiocarcinoma has revealed a high rate of actionable mutations, and several targeted therapies have been approved for treatment in the second-line metastatic setting. However, little is known about these alterations' role in localized disease treatments. Therefore, we will review the current molecular landscape of intrahepatic cholangiocarcinoma and how it has been applied to liver-directed therapy.