Epidemiology of cholangiocarcinoma: An update focusing on risk factors

Abstract

Cholangiocarcinoma is relatively rare, but high incidence rates have been reported in Eastern Asia, especially in Thailand. The etiology of this cancer of the bile ducts appears to be mostly due to specific infectious agents. In 2009, infections with the liver flukes, Clonorchis sinensis or Opistorchis viverrini, were both classified as carcinogenic to humans by the International Agency for Research on Cancer for cholangiocarcinoma. In addition, a possible association between chronic infection with hepatitis B and C viruses and cholangiocarcinoma was also noted. The meta-analysis of published literature revealed the summary relative risks of infection with liver fluke (both Opistorchis viverrini and Clonorchis sinensis), hepatitis B virus, and hepatitis C virus to be 4.8 (95% confidence interval [95% CI]: 2.8-8.4), 2.6 (95% CI: 1.5-4.6), and 1.8 (95% CI: 1.4-2.4), respectively -liver fluke infection being the strongest risk factor for cholangiocarcinoma. Countries where human liver fluke infection is endemic include China, Korea, Vietnam, Laos, and Cambodia. The number of infected persons with Clonorchis sinensis in China has been estimated at 12.5 million with considerable variations among different regions. A significant regional variation in Opistorchis viverrini prevalence was also noted in Thailand (average 9.6% or 6 million people). The implementation of a more intensive preventive and therapeutic program for liver fluke infection may reduce incidence rates of cholangiocarcinoma in endemic areas. Recently, advances have been made in the diagnosis and management of cholangiocarcinoma. Although progress on cholangiocarcinoma prevention and treatment has been steady, more studies related to classification and risk factors will be helpful to develop an advanced strategy to cure and prevent cholangiocarcinoma. (Cancer Sci 2010; 101: 579-585) C holangiocarcinomas (CCAs) -primarily cancers of the epithelial cells (mostly adenocarcinoma) in the bile ducts arising anywhere along the intrahepatic or extrahepatic biliary tree (1,2) -are relatively rare, but high incidence rates have been reported in Eastern Asia, especially in Thailand.(3) CCAs are highly fatal tumours, as they are clinically silent in the majority of cases.(4-9) Fortunately, survival of this cancer is improving.CCA occurs with a highly varying frequency in different areas of the world. CCA is second-most common primary liver cancer and accounted for an estimated 15% of primary liver cancer worldwide;(3) however, it varies widely by region from 5% in Japan (11) and 20% in Pusan (Busan), Korea (12) to 90% in Khon Kaen in Thailand. Recently, a rising tendency of intrahepatic CCA incidence was reported in Western countries. (13)(14)(15)(16) The reasons for this increase are not clear, but some of these increases were attributed to the switch between coding systems going from International Classification of Disease-Oncology-2 (ICD-O-2) to ICD-O-3.The etiology of CCA in Asian countries appears to be mostly linked to infections, especially infections wi...

Health Behavior Regarding Liver Flukes among Rural People in Nakhon Ratchasima, Thailand

“…Liver fluke caused by Opisthorchis viverrini, is a health problem in Thailand particularly in the northeast and north region (IARC, 1994;Shin et al, 2010;Sripa et al, 2010;Sithithaworn et al, 2012;Wongsaroj et al, 2014;Kaewpitoon et al, 2015e). O. viverrini infection is the etiology of cholangiocarcinoma (CCA) (Thamavit et al, 1978;Sripa et al, 2007;Sripa et al, 2012 ).…”

Nurses and Television as Sources of Information Effecting Behavioral Improvement Regarding Liver Flukes in Nakhon Ratchasima Province, Thailand

“…The experimental and epidemiological evidences 1 strongly indicated that O. viverrini infection is the etiology of cholangiocarcinoma (CCA) (Thamavit et al, 1978;IARC, 1994;Sripa et al, 2007), and CCA has been reported that Thailand is the highest incident of the world (Green et al, 1991;Sripa, et al, 2007;Kaewpitoon et al, 2008a;Shin, et al, 2010). CCA was the caused of death in Thai population and found that CCA was ranked 4 in male and 5 in female (Sripa and Pairojkul, 2008).…”

Development of a Community-Based Approach to Opisthorchiasis Control

“…The liver fluke, Opisthorchis viverrini (OV), continues to be a serious public health problem in north and northeast Thailand, associated with a very high incidence of cholangiocellular carcinoma (Shin et al, 2010). Over six million Thai people are estimated to be infected, and the highest prevalence rates are found in Issan and to a lesser extent in the North.…”