Risk Factors for Cholangiocarcinoma in Thailand: A Systematic Review and Meta-Analysis

Abstract

Background and objective: Cholangiocarcinoma remains a serious public health concern in Thailand. While many<br />of the risk factors for cholangiocarcinoma in western countries are well-recognized, it remains unclear whether they<br />are the same in Thailand. We set out to investigate the risk factors for cholangiocarcinoma in Thailand. Methods:<br />Starting March 4, 2016, we reviewed studies found using pre-specified keywords on SCOPUS, Pro Quest Science<br />Direct, PubMed, and online public access catalog of Khon Kaen University. Two review authors independently screened<br />studies for inclusion criteria, extracted data, and assessed the studied Risk of Bias. The Newcastle-Ottawa Scale and the<br />Joanna Briggs Institute Critical Appraisal Tools were used to assess the quality of included studies. The risk effects of<br />factors were estimated as a pooled adjusted odds ratio with a 95% confidence interval. The heterogeneity of results was<br />considered using the I-square, Tau-square and Chi-square statistics. Results: A strong association was found between<br />cholangiocarcinoma and age, Opisthorchis viverrini infection, eating raw cyprinoid fish, family history of cancer, liquor<br />consumption, and taking praziquantel. There was only a mild association found between eating nitrite-containing foods,<br />fresh vegetables, education, smoking behavior, and sex. No association was found between cholangiocarcinoma and<br />eating fermented fish (Pla-ra), northeastern Thai or Chinese sausage, sticky rice, meat, chewing betel nut, or eating<br />fruit. There were two protective factors including fresh vegetables consumption and education attainment. Conclusion:<br />There are unique risk factors of cholangiocarcinoma in Thailand, including age, Opisthorchis