Striking trends in the cholangiocarcinoma incidence and mortality in the United States of America 1979–1998

Abstract

Background and Methods: Cholangiocarcinoma (CCA) arises from both intra and extrahepatic bile ducts and has been considered a rare tumor in the United States. Recently, worldwide rising mortality due to primary liver tumors including intrahepatic cholangiocarcinoma (IHCC) has been reported. We have analyzed data from the Surveillance, Epidemiology, and End Results (SEER) database to determine the age-adjusted incidence of cholangiocarcinoma and data from the U.S. Vital-Statistics database to determine age-adjusted mortality rates. Results: The incidence of I HCC (leD-9 155.1) progressively increased from 0.12 to 0.81 per 100,000 population between 1979 and 1996 (Figure) associated with a rise in mortality from 0.2 to 0.9 during 1979-1998. Increase in mortality was higher in men (0.2 to 1.1) compared with women (0.2 to 0.8). The percent change in mortality was higher in those aged >75 years. In contrast, the incidence of extrahepatic cholangiocarcinoma (EHCC lOB-9 156.1) decreased from 1.1 to 0.7 (Figure) and the mortality reduced from 0.6 to 0.3 associated with a similar reduction in mortality secondary to gall bladder cancer (iCD-9 156.B} from 1.2 to 0.7 per 100,000 population during this period. Conclusions: The incidence and mortality of intrahepatic cholangiocarcinoma in the USA has increased five fold in the last two decades, the rate of rise of which far exceeds that of hepatocellular carcinoma. This is not readily explained by diagnostic transfer from other tumors or improved diagnosis. Opposing trends in intra and extra hepatic cholangiocarcinoma suggest dissimilar pathogenesis.