1. Oral oncogenic HPV prevalence was more than 4 times higher among men than women.
2.The gender difference was due primarily to a higher number of lifetime sexual partners and a stronger association between sexual behavior and infection among men.
Evidence Rating Level: 3 (Average)
Study Rundown: It is widely known that the sexually transmitted human papillomavirus (HPV) causes cervical and genital cancers, but it was notv until the 1990s that researchers discovered the same infection was causing an increasing number of head and neck, and oropharyngeal, cancers. HPV is currently estimated to cause 70 percent of oropharyngeal cancers and by 2020, experts anticipate cases will continue increasing in number to surpass those of cervical cancer for the most common HPV associated malignancy. Interestingly, in multiple developed countries worldwide the incidence is rising more in men than in women. In the United States, men are 3 to 5 times more likely to have an HPV positive head and neck cancer. The reasons behind this difference remain unknown. In this study, a team of researchers led by Maura Gillison, one of the first to discover the connection between HPV and oral cancers, compared the epidemiology of oral oncologic HPV infections between men and women.
Findings demonstrated that oral oncogenic HPV prevalence was significantly higher among men than women. Men were found to have a higher number of lifetime sexual partners and a greater per-partner increased risk of infection compared to women. This result is in keeping with the hypothesis that there is a higher risk for HPV transmission when men perform oral sex, although gender differences in immune responses may also contribute.
Strengths of this study included a large, nationally representative sample. One notable limitation is that sexual activity was self-reported—it is well document that men tend to over-report, while women under-report sexual partners. Future studies comparing specific sexual behaviors and risk of HPV infection are warranted.
Click to read the study in Cancer Research
Relevant Reading: Case-Control Study of Human Papillomavirus and Oropharyngeal Cancer
In-Depth [cross-sectional study]: Participants in the U.S. National Health and Nutritional Examination Surveys (NHANES) from 2009-2012 who agreed to participate in the Oral HPV Protocol provided oral samples, which were analyzed for the presence of 37 HPV types (n=9,480). Incidence of oral oncogenic HPV infection was compared with self-reported data on sexual practices, tobacco, alcohol and drug use.
The prevalence of oral oncogenic HPV infections was higher in men than women (6.5% vs. 1.5%, p<0.001). For both genders, prevalence was directly associated with age, smoking, and lifetime number of sexual partners (all p<0.02). On average, men had more lifetime sexual partners than women (18 vs. 7, p<0.001). When stratified by number of partners, there was a difference in male-female prevalence that increased with number of lifetime partners, from 0.2% for women with one partner versus 0.6% for males with one partner to 3.7% for women with over 20 partners partners and 13.9% of men with over 20 partners partners (both p<0.05).
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