An overview of extrahepatic cholangiocarcinoma: from here to where?

Extrahepatic cholangiocarcinoma (eCCA) contains perihilar cholangiocarcinoma and distal cholangiocarcinoma both of which can arise at any point of the biliary tree and originate from disparate anatomical sites. Generally, the incidence of eCCA is increasing globally. Though surgical resection is the principal treatment of choice for the early stages of eCCA, optimal survival remains restricted by the high risk of recurrence when most patients are present with unresectable disease or distant metastasis. Furthermore, both intra- and intertumoral heterogeneity make it laborious to determine molecularly targeted therapies. In this review, we mainly focused on current findings in the field of eCCA, mostly including epidemiology, genomic abnormalities, molecular pathogenesis, tumor microenvironment, and other details while a summary of the biological mechanisms driving eCCA may shed light on intricate tumorigenesis and feasible treatment strategies.

Automated summary

Extrahepatic cholangiocarcinoma (eCCA) includes perihilar cholangiocarcinoma and distal cholangiocarcinoma, which can occur at any point in the bile duct and originate from different anatomical sites. The incidence of eCCA is increasing globally. Surgical resection is the preferred treatment for early stage eCCA, but high risk of recurrence in unresectable or metastatic disease limits optimal survival. Intra- and intertumoral heterogeneity make it difficult to determine targeted therapies. This review focuses on current findings in eCCA, including epidemiology, genomic abnormalities, molecular pathogenesis, tumor microenvironment, and potential treatment strategies based on understanding the complex tumorigenesis.