Hello. I'm Dr. Sandra Fryhofer. Welcome to Medicine Matters. The topic? Human papillomavirus (HPV) in men: an update from the Journal of Lower Genital Tract Disease.
Here's why it matters.
HPV types 16 and 18 cause 70% of all cervical cancers in women, but how does this virus affect disease, including cancer, in men? HPV is linked to oropharyngeal cancer in both men and women. The published prevalence rates for oral HPV are around 4%-5%. However, oral HPV is found in the tonsils in the base of the tongue, which makes it harder to detect. Therefore, oral HPV prevalence is probably underestimated.
For both men and women, sexual behaviors including multiple sex partners and having oral sex are linked to increased risk for HPV. For men, having sex with other men is also a risk factor. The study states that 20% of men have detectable HPV in the anogenital area. For heterosexual men, the most common risk factor is the number of past and current sexual partners.
HPV infections in men clear quickly most of the time. In one study, 94% of penile and scrotal infections cleared within a year. HPV types 6 and 11 cause more than 90% of genital warts in males and in females. Each year, as many as 3-4 million men, most under age 30, suffer genital warts. The highest rate is in the 25- to 29-year-old age group.
HPV increases risk for penile cancer, which is relatively rare in the United States -- about 1 per 100,000 men, with a mean age of 63-67. Unfortunately, this rate has increased twenty-fold in South American, African, and Asian men. Mitigating risk factors, such as smoking, high-risk sexual activity, and phimosis, may play a role in these differences. Of note, circumcision is protective against penile cancer.
Anal cancer is on the rise in both women and men. Of note, overall, women have higher rates of anal cancer than men do, with a total of 1600 new cases each year in women compared with 900 in men. For women, the anal cancer rate is 1.4 per 100,000, and for men it is 1 per 100,000. However, 90% of men who have sex with men have detectable HPV. Not surprisingly, HIV-infected men who have sex with men are the group at greatest risk for anal cancer. Their yearly incidence rate is 25-100 per 100,000.
Nearly 90% of all anal cancer in men is caused by HPV types 16 and 18. With this in mind, is there a role for anal cytology? Many centers screen men who have sex with men, although the rate of progression from high-grade anal intraepithelial neoplasia to full-blown cancer is unknown. The benefit, if any, from screening needs further study.
Preventive measures, however, using 2 HPV vaccines are currently available:
The quadrivalent vaccine (Gardasil®) protects against types 6, 11, 16, and 18, and is approved by the US Food and Drug Administration (FDA) for males and females aged 9-26 years; and
The bivalent vaccine (Cervarix®) protects against types 16 and 18 but is FDA-approved only for females.
Men are at risk for HPV-related disease, and yet even though there is a clear and proven medical benefit for vaccinations in boys and men, the cost effectiveness remains controversial.
The authors of this study have received honoraria from Merck and GlaxoSmithKline, the makers of HPV vaccines.
For Medicine Matters, I'm Dr. Sandra Fryhofer.
Medscape Internal Medicine © 2011
Cite this: Sandra Adamson Fryhofer. HPV Vaccine in Men: A Good Thing But Worth the Cost? - Medscape - Oct 05, 2011.