Extended coverage of HPV vaccination in middle-aged adults to prevent oropharyngeal cancers

Keywords: :

• HPV vaccination
• middle-aged males
• oral cancer
• pharyngeal cancer
• immunization schedules

To the Editor

The US Centers for Disease Control and Prevention recommendation for Human papilloma virus (HPV) immunization in adults¹ is based on its demonstrated efficacy to prevent genital warts and anogenital cancers in randomized clinical trials.² For females, either a quadrivalent HPV4 vaccine or a bivalent HPV2 vaccine is recommended in a three-dose series for routine vaccination at 11 or 12 y of age and also for those aged 13–26 y, if not vaccinated previously. For males, HPV4 vaccine is recommended in a three-dose series for routine vaccination at age 11 or 12 y and for those aged 13–21 y, if not previously vaccinated. Males aged 22–26 y may also be vaccinated if there were medical, occupational, life style or other indications.¹

The rising incidence, both in Europe and the US, of oropharyngeal squamous cell carcinoma (OSCC), including tonsillar and tongue base cancers, is attributed to an epidemic of HPV infection.³ While the incidence of HPV-related oral cavity and oropharyngeal cancers is increasing, there has been a decrease in the incidence of cancer at HPV-unrelated sites. In the oral cavity, about 35% of oropharyngeal cancers and 25% of other oral cavity cancers are HPV-positive^4.

Independent HPV transmission by the oral route was seen in Japanese females during characterization of HPV infection and HPV types in the oral cavity and cervix. In 12 women with oral HPV infection, only two were infected with the concordant HPV genotype in the cervix.⁴

The possibility to vaccinate against HPV-positive OSCC including tonsil- and tongue-based cancers should be explored both at regional and international levels.

HPV vaccinations during the third or higher decades in life would address the prevalence of oral HPV infection in middle-aged adults even though vaccine efficacy against oral HPV infections is presently unknown.³

In conclusion, feasibility studies in men toward HPV vaccinations to prevent HPV-related cancers at non-cervical sites would be beneficial toward prevention of a similar number of cervical cancer cases that have been prevented globally.⁵ Almost one-quarter of the potentially preventable HPV-OSCC cases are in men, and men have not been, as rule, included in the current national HPV immunization programs.

Acknowledgment

The secretarial assistance of Mr. Parul Bharadwaj is acknowledged.