Precision Medicine in Cholangiocarcinoma: Past, Present, and Future.

Cholangiocarcinoma (CCA), or biliary tract cancer, has a poor prognosis. The median survival time among patients with CCA is under 2 years from diagnosis, and the global 5-year survival rate is only 10%. First-line therapy with chemotherapeutic agents, gemcitabine plus cisplatin, has traditionally been used to treat unresectable advanced CCA. In recent years, precision medicine has become a mainstream cancer treatment due to innovative next-generation sequencing technology. Several genetic alterations, including mutations, gene fusions, and copy number variations, have been found in CCA. In this review, we summarized the current understanding of genetic profiling in CCA and targeted therapy in CCA. Owing to the high heterogeneity of CCA, tumor microenvironmental factors, and the complexity of tumor biology, only pemigatinib, infigratinib, ivosidenib, larotrbctinib, and entrectinib are currently approved for the treatment of CCA patients with fibroblast growth factor receptor 2 gene (FGFR2) fusion, isocitrate dehydrogenase gene (IDH1) mutation, and neurotrophin receptor tyrosine kinase gene (NRTK) fusion, respectively. Additional targeted therapies, including other FGFR2 inhibitors, PI3K/AKT/mTOR inhibitors, and BRAF-directed targeted therapy, have been discussed for the management of CCA, and immune checkpoint inhibitors, particularly pembrolizumab, can be administered to patients with high microsatellite instability tumors. There is a further need for improvement in precision medicine therapies in the treatment of CCA and discuss the approved and potential targeted therapies for CCA.