ABSTRACT
<p><b>OBJECTIVE</b>To explore the relationship between clonorchiasis and primary hepatocellular carcinoma (HCC) and analyze the synergistic actions of HBV infection, alcohol consumption and clonorchiasis on HCC development.</p><p><b>METHODS</b>This hospital-based case-control study was conducted among 444 HCC patients (cases) and 500 non tumor patients (controls) to compare the prevalence of clonorchiasis in the cases and the controls. The risk of clonorchiasis and the synergistic actions between HBV infection, alcohol consumption and clonorchiasis on HCC development were analyzed by crossover analysis and multiple logistic regression.</p><p><b>RESULTS</b>The prevalence of clonorchiasis in the cases (16.44%) was much higher than that of the controls (2.40%) (X2 = 56.58, P less than 0.01). In the case group, the OR value of those with clonorchiasis was 8.00 (95% CI: 4.34-14.92). The OR value was 4.82 (95% CI: 2.32-10.26) for the subjects whose clonorchiasis was diagnosed less than 10 years before their diagnosis of HCC, and was 17.54 (95% CI: 5.47-57.18) for those whose HCC was diagnosed more than 10 years ago. HBV infection, alcohol consumption and clonorchiasis showed an additive interaction in the development of HCC, with a relative excess risk of interaction of 110.43 and 18.23; attributable proportion of interaction of 0.80 and 0.63; synergy index of 5.18 and 2.84, respectively.</p><p><b>CONCLUSION</b>Clonorchiasis could be an important risk factor for HCC. When the course of clonorchiasis is prolonged, the risk of HCC could increase. HBV infection, alcohol consumption and clonorchiasis might have synergistic actions on the development of HCC.</p>