Cholangiocarcinoma: the “other” liver cancer on the rise

Abstract

The purpose of the study by Patel was to examine the secular trends in intrahepatic cholangiocarcinoma in the United States between 1973 and 1997. Incidence rates were calculated using data collected by the Surveillance, Epidemiology, and End Results program. Mortality rates were obtained from Vital Statistics data, collected by the National Center for Health Statistics. Cases included in this study were diagnosed with either a primary intrahepatic biliary tract cancer or extrahepatic biliary tract cancer (gallbladder, primary extrahepatic biliary tract, other specified extrahepatic biliary tract). The age-adjusted incidence rates of intrahepatic cholangiocarcinoma significantly increased from 0.13 per 100,000 in 1973 to 0.67 per 100,000 in 1997, with an overall annual percent change of 9%. For the same cancer, the age-adjusted mortality rates significantly increased from 0.07 per 100,000 in 1973 to 0.69 per 100,000 in 1997. There were no significant differences between men and women. In contrast, deaths from extrahepatic biliary tract cancers progressively decreased during the same time period. The second article by Taylor-Robinson et al. examined mortality statistics collected in England and Wales to explore time trends in liver cancer deaths using data from the Office for National Statistics in London for the years 1968 through 1996. The total number of deaths caused by malignant liver tumors increased steadily from 967 in 1968 to 1,822 in 1996. The age-adjusted mortality rate related to liver cancer increased from 1.29 per 100,000 to 1.93 per 100,000 in women, and from 2.56 per 100,000 to 3.70 per 100,000 in men. Of all liver cancer types, the most significant rise in mortality was attributed to intrahepatic cholangiocarcinoma. The total number of intrahepatic cholangiocarcinoma increased from 38 in 1968 to 736 in 1996 and was similar for men and women. Conversely, a decrease was observed in the total number of deaths and age-adjusted mortality rates for gallbladder, extrahepatic biliary, and pancreatic carcinomas. Based on these findings, the authors concluded that the observed increase in liver cancer deaths occurring in England and Wales was caused by a steady increase in intrahepatic cholangiocarcinoma.