Plasma Lipidomics as a Tool for Diagnosis of Extrahepatic Cholangiocarcinoma in Biliary Strictures: a Pilot Study

Biliary obstruction is a common clinical manifestation of various conditions, including extrahepatic cholangiocarcinoma. However, a screening test for diagnosis of extrahepatic cholangiocarcinoma in patients with biliary obstruction is not yet available. According to the rationale that the biliary system plays a major role in lipid metabolism, biliary obstruction may interfere with lipid profiles in the body. Therefore, plasma lipidomics may help indicate the presence or status of disease in biliary obstruction suspected extrahepatic cholangiocarcinoma. This study aimed to use plasma lipidomics for diagnosis of extrahepatic cholangiocarcinoma in patients with biliary obstruction. Plasma from healthy volunteers, patients with benign biliary obstruction extrahepatic cholangiocarcinoma, and other related cancers were used in this study. Plasma lipids were extracted and lipidomic analysis was performed using matrix-assisted laser desorption ionization time-of-flight mass spectrometry. Lipid profiles from extrahepatic cholangiocarcinoma patients showed significant differences from both normal and benign biliary obstruction conditions, with no distinction between the latter two. Relative intensity of the selected lipid mass was able to successfully differentiate all extrahepatic cholangiocarcinoma samples from patient samples taken from healthy volunteers, patients with benign biliary obstruction, and patients with other related cancers. In conclusion, lipidomics is a non-invasive method with high sensitivity and specificity for identification of extrahepatic cholangiocarcinoma in patients with biliary obstruction.