Abstract
BACKGROUND: Hepatitis B (HBV) and hepatitis C (HCV) viruses are diseases of global public health concern and are associated with liver cancer. Recent studies have revealed associations between hepatic viral infections and extrahepatic cancers. This study aimed to explore the associations between hepatitis B and C viruses and cancer at baseline in the Taiwan Biobank database while controlling for a wide range of confounding variables. METHODS: In a cross-sectional study of adults aged > 20 years, we compared the distribution of demographic factors, lifestyle, and comorbidities between viral and nonviral hepatic groups using the chi-square test. Univariate and multivariate logistic regressions were performed to observe the associations between hepatitis B and C viral infections and cancers by estimating the odds ratio (OR) and 95% confidence interval (CI). Multivariate regression analysis was adjusted for sociodemographic factors, lifestyle, and comorbidities. RESULTS: From the database, 2955 participants were identified as having HCV infection, 15,305 as having HBV infection, and 140,108 as the nonviral group. HBV infection was associated with an increased likelihood of liver cancer (adjusted OR (aOR) = 6.60, 95% CI = 3.21-13.57, P < 0.001) and ovarian cancer (aOR = 4.63, 95% CI = 1.98-10.83, P = 0.001). HCV infection was observed to increase the likelihood of liver cancer (aOR = 4.90, 95% CI = 1.37-17.53, P = 0.015), ovarian cancer (aOR = 8.50, 95% CI = 1.78-40.69, P = 0.007), and kidney cancer (aOR = 12.89, 95% CI = 2.41-69.01, P = 0.003). CONCLUSION: Our findings suggest that hepatic viral infections are associated with intra- and extrahepatic cancers. However, being cross-sectional, causal inferences cannot be made. A recall-by-genotype study is recommended to further investigate the causality of these associations.