What are the effects of Human Papillomavirus (HPV) on men?

HPV Effects in Men

HPV infection in men causes genital warts, penile cancer, anal cancer, and oropharyngeal cancer, with approximately 70,000 cases of HPV-associated cancers occurring globally in men each year, predominantly caused by HPV types 16 and 18. 1

Prevalence and Natural History

HPV infection is extremely common in men:

• Genital HPV prevalence ranges from 50-70% in sexually active men, affecting the penile shaft, glans penis, coronal sulcus, semen, scrotal, perianal, and anal regions 2
• The cumulative incidence of anogenital HPV infection in sexually active men is 29-40% over a 12-month period 1
• Unlike women, HPV infection rates in men remain relatively constant across age groups at 39,41, and 33 cases per 100 person-years in the 18-30,31-44, and 45-70 age groups, respectively 1
• Median time to HPV clearance in men is 5.9-7.5 months, with 75% of infections clearing within 12 months 3, 1

Clinical Manifestations

Genital Warts

• Approximately 90% of genital warts are caused by HPV types 6 and 11 1, 3
• Estimated 1% of sexually active men have clinically apparent genital warts 1
• Average time to wart development after HPV 6 or 11 infection is 6-10 months (range up to 18 months) 1
• Genital warts are highly infectious, with approximately 65% of people who have sex with an infected partner developing warts themselves 3
• 20-30% of warts regress spontaneously, but recurrence is common (approximately 30%) even after treatment 1

Penile Cancer

• Approximately 40-50% of invasive penile carcinomas are attributable to HPV, with HPV types 16,18, and 6/11 being the most commonly detected genotypes 4, 5
• Basaloid and warty histologic subtypes of penile cancer are most likely to test positive for HPV 4
• Risk factors include lack of neonatal circumcision, phimosis, and anogenital warts 4
• Circumcision has been associated with reduced detection of HPV infection in men 3

Anal Cancer

• HPV is associated with approximately 90% of anal squamous cell cancers 1, 5
• Anal cancer incidence in men is 1.3 per 100,000, but dramatically higher in high-risk groups 1
• HIV-positive men who have sex with men (MSM) have an incidence of 85 cases per 100,000 person-years 1
• HIV-positive heterosexual men have 32 cases per 100,000 person-years 1
• HIV-negative MSM have 19 cases per 100,000 person-years 1
• Anal intraepithelial neoplasia (AIN) is recognized as a precursor to anal cancer 1

Oropharyngeal Cancer

• Oropharyngeal HPV infection prevalence is significantly higher in men than women (10.1% vs 3.6%) 1
• HPV is responsible for 63-72% of oropharyngeal cancers, with higher rates in males (72%) than females (63%) 5
• HPV types 16 and 58 are the leading subtypes in oropharyngeal cancer, accounting for 70% and 12% respectively 1
• Risk factors include higher number of lifetime oral-sexual partners, concurrent genital HPV infections, older age, and current smoking intensity 1
• The incidence of HPV-related head and neck cancer has increased 181% in recent decades 1

Recurrent Respiratory Papillomatosis (RRP)

• HPV types 6 or 11 rarely cause recurrent respiratory papillomatosis, characterized by recurrent warts in the upper respiratory tract, particularly the larynx 1
• Juvenile-onset RRP (JORRP) has an estimated incidence of 0.12 to 2.1 cases per 100,000 children aged <18 years 1
• JORRP is believed to result from vertical transmission during delivery, though median age of diagnosis is 4 years 1
• The disease requires a median of 13 lifetime surgeries to remove warts and maintain an open airway 1

Impact on Male Fertility

• HPV semen infection occurs in approximately 10% of men from the general population and 16% of men with unexplained infertility 2
• HPV semen infection is most related to asthenozoospermia and anti-sperm antibodies (ASAs) 2

Prevention and Vaccination

• The quadrivalent HPV vaccine (Gardasil) has been shown to be highly effective in reducing external genital lesions in young men 6, 1
• Male partners can be vaccinated with the quadrivalent vaccine to prevent genital warts 1
• HPV vaccination can prevent up to 90% of HPV-related cancers 5
• More than 80% of HPV-related cancers in men are caused by HPV16 and 18, increasing to over 90% when HPV16, 18,31,33,45,52, and 58 are included 1

Clinical Testing Limitations

No clinically validated test exists for men to determine if they have HPV infection 1. The most common manifestation of HPV infection in men is genital warts, while high-risk HPV types seldom cause visible genital warts 1.

Key Clinical Pitfalls

• Unlike cervical cancer, there are no standardized screening recommendations for most HPV-related cancers in men, making prevention through vaccination particularly important 5
• Low awareness of HPV in males may be a barrier to vaccine uptake 3
• Partners in long-term relationships tend to share HPV, and sexual partners of HPV-infected patients also likely have HPV, even without signs or symptoms 1