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