Molecular profiling of intrahepatic and extrahepatic cholangiocarcinoma using next generation sequencing.

Cholangiocarcinoma is a heterogeneous malignant process, which is further classified into intrahepatic cholangiocarcinoma (ICC) and extrahepatic cholangiocarcinoma (ECC). The poor prognosis of the disease is partly due to the lack of understanding of the disease mechanism. Multiple gene alterations identified by various molecular techniques have been described recently. As a result, multiple targeted therapies for ICC and ECC are being developed. In this study, we identified and compared somatic mutations in ICC and ECC patients using next generation sequencing (NGS) (Ampliseq Cancer Hotspot Panel v2 and Ion Torrent 318v2 chips). Eleven of 16 samples passed internal quality control established for NGS testing. ICC cases (n=3) showed IDH1 (33.3%) and NRAS (33.3%) mutations. Meanwhile, TP53 (75%), KRAS (50%), and BRAF (12.5%) mutations were identified in ECC cases (n=8). Our study confirmed the molecular heterogeneity of ICC and ECC using NGS. This information will be important for individual patients as targeted therapies for ICC and ECC become available in the future.