The incidence rates of cholangiocarcinoma (CC) vary greatly among different areas
of the world, and this variation is related to distribution of risk factors. Intrahepatic
cholangiocarcinoma (ICC) and extrahepatic cholangiocarcinoma (ECC) have different
epidemiological features. Recent data show that the incidence and mortality rates
of ICC have been increasing in several areas around the world. On the other hand,
the incidence and mortality rates of ECC have been decreasing. For example, in the
United States, the age-adjusted incidence rates of ICC increased by 165% from 0.32
per 100,000 in 1975 to 1979 to 0.85 per 100,000 in 1995 to 1999, whereas ECC declined
by 14%. In the meantime, there has been very little improvement in long-term survival,
which remains dismal (3.5%). Men are affected 1.5 times more than women are, and Asians
are affected almost 2 times more than whites and blacks. There are few well-established
risk factors for CC, including primary sclerosing cholangitis, liver fluke infestations,
hepatolithiasis, Thorotrast exposure, and choledochal cysts. None of these risk factors
can explain the recent increasing trends of ICC in the United States. Some data, however,
point to a potential role for chronic liver disease, hepatitis C, and probably hepatitis
B infections in the development of ICC.
KEYWORDS
Extrahepatic - survival - risk factors - incidence - SEER
REFERENCES
Opisthorchis viverrini -infected Syrian golden hamsters.
Cancer Res.
1978;
38
4634-4639
Opisthorchis infestation and carcinogen dose-dependence of cholangiocarcinoma induction in Syrian
golden hamsters.
Virchows Arch B Cell Pathol Incl Mol Pathol.
1987;
54
52-58
Clonorchis sinensis for the risk of liver cancer: a case-control study in Pusan, Korea.
Int J Epidemiol.
1996;
25
933-940
hasheme@bcm.tmc.edu
