The Potential Impact of Prophylactic HPV Vaccination on Oropharynx Cancer

Oropharyngeal cancer (OPC) is significantly increasing in incidence in the United States. Given that these epidemiologic trends are driven by HPV, the potential impact of prophylactic HPV vaccines on the prevention of OPC is of interest. To date, the primary evidence supporting the approval of current prophylactic HPV vaccines are large phase III clinical trials focused on prevention of genital disease (cervical and anal cancer, as well as genital warts). These trials reported 89-98% vaccine efficacy for prevention of both premalignant lesions and persistent genital infection. However, these trials were designed before the etiologic relationship between HPV and oropharyngeal cancer was established. There are differences in the epidemiology of oral and genital HPV infection, such as differences in age and gender distributions, which suggest that the vaccine efficacy shown in genital cancers may not be directly translatable to the oropharynx. Evaluation of vaccine efficacy is challenging in the oropharynx because no premalignant lesions analogous to cervical intraepithelial neoplasia (CIN) in cervical cancer has been identified. In order to truly investigate the efficacy of these vaccines in the oropharynx, additional clinical trials with feasible endpoints are needed.