To identify the risk factors of
oral cancer, we investigated the association between
chronic hepatitis C (CHC) and
oral cancer, and the development of
oral cancer after anti-hepatitis C virus (HCV)
therapy. We conducted a nationwide, population-based cohort study from 2004 to 2012 from the Taiwan National Health Insurance Research Database. CHC patients without anti-HCV
therapy were matched with those non-HCV patients by age, sex and comorbidities. Moreover, CHC patients who underwent pegylated
interferon and
ribavirin (PegIFN/RBV) anti-HCV
therapy were matched with CHC patients without anti-HCV
therapy. A total of 100,058 patients were included in the HCV cohort and non-HCV cohorts, respectively. Their mean age was 59 years and 50% of these were male. CHC
infection significantly increased the cumulative incidence of
lichen planus and
oral cancer. After adjustment for confounders and competing mortality, CHC
infection significantly increased the risk of
oral cancer (hazard ratio [HR]: 1.677, 95% confidence interval [CI]: 1.392-2.020, p < 0.001). Another 23,735 CHC patients without anti-HCV
therapy were matched with 23,735 CHC patients in the treatment cohort. After adjustment for confounders and competing for mortality, the risk of
oral cancer was significantly reduced in CHC patients receiving anti-HCV
therapy (HR: 0.652, 95% CI: 0.479-0.887, p = 0.007). To minimize the inclusion of pre-existing unidentified
oral cancer, we excluded
oral cancer developed within the first year of CHC or anti-HCV
therapy and found these associations remained statistically significant. In conclusion, CHC significantly increases the risk of
oral cancer. Moreover, PegIFN/RBV
antiviral therapy significantly reduces the risk of HCV-related
oral cancer.