Human Papilloma Virus vaccine and prevention of head and neck cancer, what is the current evidence?

Abstract

Objectives Human Papilloma Virus is associated with the development of cancers in the head and neck region. We have witnessed, in the last decades, an increase in number of cases directly related to HPV infection, in particular in the Western Countries. Recently the FDA expanded the indications for Gardasil-9® to include the prevention of head and neck cancer. Objective of this paper is to review the evidence supporting its use.

Materials and methods Bibliographic review enquiring Medline, Web of Science and the Cochrane Library to assess the efficacy of vaccination against oncogenic HPV in the prevention of head and neck squamous cell carcinoma.

Results Two prospective and 4 retrospective studies have evaluated vaccination in prevention of head and neck cancer, using persistent oral infection as surrogate of efficacy. All studies showed lower prevalence of oral infection up to 4 years following vaccination. Vaccine efficacy was estimated between 88 and 93.3%. Because of low vaccine coverage the estimated population-level effect against oral HPV16/18/6/11 infections was only 17.0%.

Conclusions Antibodies concentration in the oral fluid correlate with serum level, but the threshold to ensure protection is unknown. Duration of protection has not been established. HPV vaccination can provide protection from re-infection (at different mucosal sites) in previously exposed individuals, suggesting possible use of HPV vaccine later in life. Other studies should focus on confirming causal relationship between vaccination and prevention of persistent oral infection and investigate the duration of efficacy, which is crucial in its effectiveness against HNSCC.