Human Papillomavirus infection-linked Cancers in Men
Human Papillomavirus (HPV) infection is the most common sexually transmitted infection (STI) – about 6.2 million people are infected every year in the United States. And since HPV infection often shows no symptoms, these infections are not caught in many men and women.1 To prevent complications of HPV infection, routine Pap tests for women are recommended to detect cervical changes caused by HPV infection. However, there are no standardized tests for HPV in men. As a result of the lack of screening and testing guidelines, men may act as silent carriers of HPV infection.2 HPV most commonly causes genital warts, but some strains of the virus can cause cancer. The burden of HPV-related cancers is affecting not only women, but also men. HPV is known to cause cervical cancer in women and penile and anal cancers in men. Several studies have identified certain HPV types as cancer-causing strains in men.
Few studies have examined the prevalence of HPV infection in men and risk factors associated with it. A recent study reported that 50% of men ages 18 to 70 years are infected with HPV. The study involved 1,159 men from the United States, Brazil and Mexico and reported that the frequency of a new genital HPV infection was 38.4 per 1,000 person months (95% CI 34.3-43.0).3 Furthermore, having more than one lifetime sexual partner increased the chance of a cancer-causing HPV infection 2.4 times.
HPV is known to cause penile and anal cancers in men; commonly associated with HPV 16 and 18. About 40% of penile cancers are caused by HPV. Penile cancer is less prevalent than HPV-associated anal cancer, which affects both men and women.4 Condoms may offer some risk reduction for penile cancers. But, areas not covered by condoms such as the perineal/perianal site in men are still at risk of infection even if condoms are used every time.
However, new research reveals the virus also causes cancers of the oral cavity, head and neck. In fact, cancers associated with HPV are on the rise, especially those of the tonsils and base of the tongue.5
Cancers of the head and neck caused by HPV are not a new occurrence. The virus has been linked to oral cancer since 1983, when an association between the two was first reported.5 The National Cancer Institute estimates about 64% of cancers of the oral cavity, head and neck in the U.S. are caused by HPV. In the United States about 37,000 people were diagnosed with oral cancer in 2010. HPV beat out alcohol and tobacco use as the leading cause of oral and throat cancers.6 But what exactly is causing the surge in oral HPV infections? The most common mode of transmission is oral sex. Many people, especially teens, believe oral sex has no consequences. Research reports that the more oral sex partners a person has, the higher their risk of infection. A person who has performed oral sex on six or more partners has an eight-fold increased risk for oral cancers caused by HPV as compared to someone who has never performed oral sex.7 The fact is that “oral sex” is sex and carries a risk of contracting STIs.
Although the link between oral cancer and HPV is not a new one, the rising number of cases has become a recent problem. A Swedish study reported that HPV-positive tumors increased from 23% in the 1970s to 57% in the 1990s. By 2005, this number had increased to 93%.3 HPV-16 is the strain linked to more than 90% of HPV-related cancers of the head and neck. Only about 4% of men are infected with this strain,2 but other cancer causing strains of the virus do exist.
So what can be done to prevent HPV infection and their consequences in men? Vaccination may provide partial protection. Vaccines such as Gardasil and Cervarix are strongly recommended for females ages 9-26. Men face the same risk of infection as women, and may unknowingly act as carriers of the virus and continue to spread it. The prevalence of HPV-related cancers is even more alarming when we consider that 50% of men have an HPV infection.2
Recently, the HPV vaccine has been approved for young males aged 9 to 26 years as well, although routine vaccination is not yet recommended.8 Vaccinating both men and women can be a way to combat the spread of HPV and HPV-related cancers, but it does not solve the problem.
Since neither condoms nor vaccines can truly protect against HPV infection, men and women need to avoid risky sexual behaviors, including oral sex, to avoid HPV infection. Abstinence outside a committed long term relationship is the only way to protect oneself completely.
1. Dunne EF, Nielson CM, Stone KM, Markowitz LE, Giuliano AR. Prevalence of HPV Infection among Men: A Systematic Review of the Literature. J Infect Dis. 2006; 194 (8):1044-1057.
2. Vardas E, Giuliano AR, Goldstone S, et al. External Genital Human Papillomavirus Prevalence and Associated Factors Among Heterosexual Men on 5 Continents. J Infect Dis. 2011;203:58-65.
3. Giuliano A, Lee Ji-Hyun, Fulp William, et al. Incidence and clearance of genital human papillomavirus infection in men (HIM): a cohort study. The Lancet. 2011; S0140-6736 (10):62342-2.
4. Ortoski R, Kell C. Anal Cancer and Screening Guidelines for HPV in Men. J Am Osteopath Assoc. 2011; S2 (3):S35-S43
5. Hannisdal K, Schjolberg A, DeAngelis P, et al. Human papillomavirus (HPV)-positive tonsillar carcinomas are frequent and have a favourable prognosis in males in Norway. Acta Oto-Laryngologica. 2010; 130:293-299.
6. D’Souza G, Kreimer AR, Viscidi R, et al. Case-Control Study of Human Papillomavirus and Oropharyngeal Cancer. New England Journal of Medicine. 2007:1944-1956.
7. D’Souza G, Agrawal Y, Halpern J, Bodison S, Gillison ML. Oral sexual behaviors associated with prevalent oral human papillomavirus infection. J Infect Dis 2009;199:1263-1269.
8. Center for Disease Control and Prevention (CDC). FDA licensure of quadrivalent human papillomavirus vaccine (HPV4, Gardasil) for use in males and guidance from the Advisory Committee on Immunization Practices (ACIP).MMWR Morb Mortal Wkly Rep. 2010 May 28;59(20):630-2.
Reviewed: April 2011