Human Papillomavirus Vaccine to End Oropharyngeal Cancer. A Systematic Review and Meta-Analysis.

Abstract

Oropharyngeal cancer (OPC) is currently the most frequent human papillomavirus (HPV)-related malignancy in high-income countries. Oral HPV16 infection is the cause of HPV-related OPC in more than 90% of cases and is primarily (90%) linked to oral sex. This systematic review and meta-analysis aimed at comparing the prevalence of oral vaccine-type HPV infection in individuals vaccinated with HPV vaccines and unvaccinated controls. Three databases (MEDLINE, ScienceDirect, and the Cochrane Library), as well as other sources, were searched by 2 independent reviewers. Controlled studies testing the efficacy or effectiveness of licensed HPV vaccines were included. The primary end point was multiple oral HPV infections in one individual with low-risk and high-risk types. Secondary end point was the number of oral HPV16 infections. Six studies-2 randomized controlled trials and 4 cross-sectional studies-with a total of 15,240 participants were included in a meta-analysis, which showed that vaccinated individuals were 46% (risk ratio, 0.54; 95% confidence interval, 0.32-0.91) less likely to develop oral vaccine-type HPV infection (P = 0.02). A second meta-analysis of 4 studies (1 randomized controlled trial and 3 cross-sectional studies) and 13.285 participants showed 80% (risk ratio, 0.20; 95% confidence interval, 0.09-0.43) less likelihood of oral HPV16 infection (P < 0.0001). This study suggests that HPV vaccines can protect against oral vaccine-type HPV infection including high-risk HPV16 infection, thus reducing the incidence of HPV-related OPC. Vaccination against HPV, especially in males, who are predominantly affected by HPV-related OPC, could result in the prevention of this disease.