Incidence trend and prognosis of intrahepatic cholangiocarcinoma: a study based on the SEER database.

Background: Intrahepatic cholangiocarcinoma (ICC) is the second most common primary liver cancer after hepatocellular carcinoma (HCC). ICC and HCC have different cellular origins; therefore, ICC is significantly different from HCC in terms of aetiology, mechanism, tumour biological behaviour, treatment methods, and prognosis. The objective of this study was to investigate the current incidence trend and prognosis of ICC and deepen the understanding of ICC.