Abstract & Commentary

Oral HPV: A Potential Time Bomb for Cancer Development, Especially in Men

By Stan Deresinski, MD, FACP, FIDSA, Clinical Professor of Medicine, Stanford University, Associate Chief of Infectious Diseases, Santa Clara Valley Medical Center, is Editor for Infectious Disease Alert.

Source: Gillison ML, et al. Prevalence of oral HPV infection in the United States, 2009-2010. JAMA 2012;307:693-703.

Gillison and colleagues examined the prevalence of oral human papillomavirus (HPV) infections in civilian non-institutionalized individuals 14 – 69 years of age in the U.S. by conducting a cross-sectional study as part of the National Health and Nutrition Examination Survey (NHANES). Oral rinse samples were obtained from 5579 participants and HPV DNA was detected by PCR with the ability to detect 37 viral types.

The prevalence of oral HPV infection in the entire cohort was 6.9% and 3.7% of the total were infected with HPV types considered potentially oncogenic; 1% were infected with HPV-16, the type most associated with the development of malignancies. For all HPV types, there was a bimodal age distribution with peaks in those aged 30 to 34 years and 60 to 64 years. The prevalence in men was significantly greater than in women – 10.1% vs. 3.6% (P<0.001). Independent predictors of oral HPV infection included age, gender, smoking intensity and the lifetime number of sexual partners. Infection prevalence was as high as 20% in individuals with >20 lifetime partners as well in those who smoked >20 cigarettes daily.

Commentary

HPV infection is detected in 25% of head and neck squamous cell cancers and 90% of those are associated with HPV16.1 The incidence of HPV-associated oral cancers increased by 225% in the U.S. between 1988 and 2004 while the incidence of non-HPV oral malignancies, which are associated with tobacco and alcohol use, has decreased.

Oral HPV infection has previously been associated with sexual activity and this study indicates that casual non-sexual transmission does not commonly occur. While one may assume that oral-genital sex is a major means of transmission, as has previously been indicated, its distinction from other sexual activities cannot be determined in a study such as this. Nonetheless, one can posit that the approximately 3-fold higher prevalence in men than in women may be the consequence of greater risk of genital to oral transmission from women to men than in the opposite direction.

The overall prevalence of genital HPV is 42.5% in females 14-59 years of age and varied significantly by age, race or ethnicity, and number of sex partners, a proportion that is 6 times higher than the prevalence of oral HPV infection in the cohort studied here.2 Nonetheless, oropharyngeal infection is an important public health issue and the 1% prevalence of oral infection with the highly oncogenic HPV16 translates into approximately 2.1 million affected individuals in the U.S. Vaccination for prevention of HPV-associated genital warts and anogenital malignancies is recommended in the U.S. for females aged 9 – 26 years and males 9 -21 years of age. The efficacy of vaccination in preventing oral cancers is unknown at this time, but is a critical clinical issue because the increasing incidence of HPV-associated oral malignancies has led to estimates that these cancers will outnumber cervical cancers by 2020.

References

  1. Gillison ML, Koch WM, Capone RB, et al. Evidence for a causal association between human papillomavirus and a subset of head and neck cancers. J Natl Cancer Inst 2000;92(9):709-20
  2. Hariri S, Unger ER, Sternberg M, et al. Prevalence of genital human papillomavirus among females in the United States, the National Health And Nutrition Examination Survey, 2003-2006. J Infect Dis 2011;204:566-73.