Warts on the anus and the link to cancer

Dear Dr G,

I am writing to you with guilt about my past sexual encounters and hoping you can help me with this burden of remorse.

I am a 35-year-old man who has not been in a sexual relationship for at least five years.

However, a secret from my past torments me regularly.

In my late twenties, I noticed a small flower-like growth on my anus.

I went to the doctor, who told me it was an anal wart.

I was shocked to learn the wart is related to the Human Papilloma Virus (HPV), a sexually transmitted infection (STI).

I was horrified, assuming anal warts are more common in men having sex with men and I assure you, all my relationships have been heterosexual.

The doctor performed cryotherapy for the warts, which was successful for a while, but they frequently recur.

Recently, the doctor decided to biopsy the wart and found some precancerous cells called AIN.

I am terrified and would like to ask Dr G about the risks of having warts in the anus and cancer.

I thought HPV only affects women. Why is it affecting my anus?

Is it true anal warts only affect men having sex with men? Why are they affecting a heterosexual man like me?

Are these viruses oncogenic and always cause anal cancers?

What exactly is AIN and anal cancer?

What treatment do I need?

Finally, I have heard about the vaccine. Is it too late for me to have it?

Regards,

Anal Adam

The existence of genital warts has been documented since ancient Greece, but the viral cause was only identified in 1907. Today, about 80 million Americans are infected with HPV, with approximately 14 million new cases each year. Around 1% of sexually active adults have recurrent genital warts, and genital warts are caused by the transmission of HPV during sexual contact.

Of the 170 subtypes of HPV, more than 40 are spread through genital and anal contact. HPV 6 and 11 are commonly linked to anal warts. HPV transmission occurs in both men and women. Risk factors for cancer include early age of sexual intercourse, multiple partners, poor hygiene, and smoking.

Nearly all sexually active people are infected by HPV at some point, making it the most common sexually transmitted infection globally. About 90% of those affected show no symptoms, and the virus often resolves spontaneously within two years. HPV can persist, causing warts or precancerous lesions.

The oncogenic virus typically affects the cervix, vulva, and vagina in women, and the penis in men. The virus also infects the oropharyngeal cavity and anus, risking cancers in both genders. Anal warts appear as visible flower-like lesions around the anus, and normal skin tags can be mistaken for anal warts. Scraping the lesion for DNA subtype analysis is the most accurate way to diagnose.

Precancerous AIN (Anal Intraepithelial Neoplasia) can be treated with minimally invasive methods like infrared photocoagulation. However, progression to anal cancer complicates treatment. About 8,300 people are diagnosed with anal cancer annually in the United States, representing about 0.5% of new cancers.

Contrary to common belief, anal cancers do not just affect MSM (Men having Sex with Men). In fact, women are more often affected, with those above 60 having double the risk. Standard anal cancer treatment may include radical surgery and chemoradiation. The five-year survival rate in the United States is only 68%, due to late presentations.

The most effective way to protect against HPV is vaccination. Although the vaccine is recommended for sexually naïve boys and girls at age 13, protection is also effective up to age 45.

Other ways to reduce HPV transmission include reducing the number of sexual partners and avoiding sexual contact when warts are present. HPV vaccines are also recommended for individuals diagnosed with anal warts to boost immunity against HPV. Dr G advises caution regarding HPV. It’s crucial to be vaccinated and practice safe relationships to prevent complications like anal warts or cancer.