Unveil Intrahepatic Cholangiocarcinoma Heterogeneity through the Lens of Omics and Multi-Omics Approaches

Simple Summary Intrahepatic cholangiocarcinoma (iCCA) is a highly aggressive primary liver cancer leading to death in 10-15% of cases. In recent years, the iCCA worldwide incidence has been increasing, and research is currently focused on identifying valuable diagnostic biomarkers and developing specific therapies to counteract the disease despite its high heterogeneity. The use of cutting-edge and broad-spectrum applications like omics represents a successful approach to studying the intricate pathobiology of iCCA. In this review, we discuss how both single- and multi-omics studies can pave the way for identifying potential biomarkers, and more importantly, for stratifying iCCA patients. This stratification aims to enhance the therapeutic intervention through personalized medicine (PM).Abstract Intrahepatic cholangiocarcinoma (iCCA) is recognized worldwide as the second leading cause of morbidity and mortality among primary liver cancers, showing a continuously increasing incidence rate in recent years. iCCA aggressiveness is revealed through its rapid and silent intrahepatic expansion and spread through the lymphatic system leading to late diagnosis and poor prognoses. Multi-omics studies have aggregated information derived from single-omics data, providing a more comprehensive understanding of the phenomena being studied. These approaches are gradually becoming powerful tools for investigating the intricate pathobiology of iCCA, facilitating the correlation between molecular signature and phenotypic manifestation. Consequently, preliminary stratifications of iCCA patients have been proposed according to their "omics" features opening the possibility of identifying potential biomarkers for early diagnosis and developing new therapies based on personalized medicine (PM). The focus of this review is to provide new and advanced insight into the molecular pathobiology of the iCCA, starting from single- to the latest multi-omics approaches, paving the way for translating new basic research into therapeutic practices.