Cholangiocarcinomas (CCAs) are rare cancers that arise from the intrahepatic or extrahepatic biliary ductal epithelium, which are classified into intrahepatic or extrahepatic CCAs (ICCs and ECCs, respectively). ECCs are further stratified based on anatomic location into perihilar and distal CCAs. CCA accounts for approximately 10% to 15% of primary hepatic malignancies.1 In the United States, approximately 5,000 new cases of CCA are diagnosed annually, with relatively equal distribution between ICC and ECC.2 Incidence and mortality of CCA have been reported to be increasing in the United States.3 Although reasons for the increased incidence are unclear, it is thought to be partly from improved diagnostic techniques with higher detection rates and the increased incidence of hepatitis C virus infection.4
The etiology and pathogenesis of CCA remain poorly understood. Although most CCAs can arise de novo, risk factors include primary sclerosing cholangitis (PSC), alcohol consumption, liver cirrhosis, and chronic viral hepatitis infections.2,4–16 The prevalence of CCA increases steadily with age, peaking in the seventh decade.17 Although prevalence does not vary greatly by race or sex, it has been shown that in the United States, Hispanic men are at the highest risk for CCA18–20 and African American men have the lowest risk, whereas Asians/Pacific Islanders and Caucasians have prevalence rates ranging between these 2 groups.20,21 CCA has a high male predominance, except for Hispanic women, who have higher rates of ICC compared with Hispanic men.20,22 Cumulative CCA mortality rates have increased by 39% because of increased incidence and mortality rates from ICC, which is reportedly highest in American Indians and Asians.23
This retrospective study examined the evolving epidemiologic trends in incidence of CCA in the United States, while analyzing the influence of various biographic, demographic, and clinical variables on the survival of patients with CCA.
The authors have disclosed that they have no financial interests, arrangements, affiliations, or commercial interests with the manufacturers of any products discussed in this article or their competitors.
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