Human Papillomavirus Infection and Bladder Cancer Risk: A Meta-analysis

Background. Despite an increase in the number of molecular epidemiological studies conducted in recent years to evaluate the association between human papillomavirus (HPV) infection and risk of bladder cancer, the studies remain inconclusive. Methods. The prevalence of HPV in bladder cancer was estimated by pooling data from 52 studies, taking into consideration the heterogeneity from major related parameters including study region, histological type, HPV DNA specimen, publication calendar period, and detection method. Moreover, the association of HPV infection with bladder cancer was tested by a meta-analysis with 19 case-control studies. Results. An HPV prevalence of 16.88% (95% confidence interval [CI], 15.53%-18.31%) among the bladder cancer cases was revealed, most of whom were high-risk HPV types (15.82% [95% CI, 14.37%-17.36%]). The prevalence varied by region, types of HPV DNA specimen, and polymerase chain reaction primers used. A significantly increased risk of bladder cancer was shown for the positivity of overall HPV (odds ratio, 2.84 [95% CI, 1.39-5.80]), which was also infuenced by HPV type, study region, HPV DNA specimen, and detection method. Conclusions. Infection of high-risk HPV types, especially HPV16, may play a role in bladder carcinogenesis.