Association between Praziquantel and Cholangiocarcinoma in Patients Infected with Opisthorchis viverrini: A Systematic Review and Meta-Analysis

Background: The liver fluke, Opisthorchis viverrini, and the associated incidence of subsequentcholangiocarcinoma (CCA) are still a public health problem in Thailand, and praziquantel (PZQ) remainsthe antihelminthic drug of choice for treatment. Evidence in hamsters shows that repeated infection and PZQtreatments could increase the risk of CCA. However, the existing evidence in humans is inconclusive regardingincreased risk of CCA with frequency of PZQ intake.
Objectives: To investigate the relationship between numberof repeated PZQ treatments and CCA in patients with O viverrini infection. Materials and
Methods: The reviewedstudies were searched in EMBASE, MEDLINE, ProQuest, PubMed and SCOPUS from inception to October,2012 using prespecified keywords. The risk of bias (ROB) of included studies was independently assessed by tworeviewers using a quality scale from the Newcastle-Ottawa Scale (NOS). Risk effect of PZQ was estimated as apooled odds ratio (OR) with its 95% confidence interval (95%CI) in the random-effects model using DerSimonianand Laird’s estimator.
Results: Three studies involving 637 patients were included. Based on the random effectsmodel performed in two included studies of 237 patients, the association between PZQ treatments and CCA wasnot statistical significant with a pooled OR of 1.8 (95%CI; 0.81 to 4.16).
Conclusions: The present systematicreview and meta-analysis provides inconclusive evidence of risk effect of PZQ on increasing the risk of CCA andsignificant methodological limitations. Further research is urgently needed to address the shortcomings foundin this review, especially the requirement for histological confirmation.