Update on human papillomavirus

Penile, anal, and oropharyngeal cancer: The potential for primary prevention with HPV vaccination

JOEL PALEFSKY, MD

To date, no HPV vaccine has been approved for use in men. However, some evidence suggests that their vaccination could reduce the burden of HPV-related disease in men and transmission of HPV to women.

HPV infection causes cancer in approximately 10,000 US men annually.¹⁸ Head and neck cancers account for the majority of these cases, followed by anal and penile cancers. Other HPV-related diseases seen in men include genital warts and recurrent respiratory papillomatosis.

HPV-associated anal cancer is increasing in prevalence, particularly among high-risk individuals, such as men who have sex with men (MSM) and HIV-positive men and women.¹⁹ The rate of anal cancer among MSM is 35 to 70 cases per 100,000 men, depending on HIV status.¹⁸ This is comparable to the rate of cervical cancer prior to the advent of cervical cytology screening, and well above the current cervical cancer rate of 8 to 10 cases per 100,000 women.

Among all MSM, 66% are infected with HPV and 42% have anal intraepithelial neoplasia, a cancer precursor.¹⁹ Two key pieces of evidence suggest that vaccination of men would be effective. First, the heavily keratinized, hair-bearing skin of external male genitalia is identical to that of the vulva. Based on this, it has been suggested that the beneficial effects of the vaccine in preventing genital warts in females may also be seen in males. Secondly, in studies, 9- to 15-year-old boys who received the quadrivalent vaccine had higher anti-HPV titers than even the young-adult women. Because the vaccine is known to be protective at the lower titers seen in the women, investigators suspect that it will also work in the boys.