For the first time, government guidelines for the management of opportunistic infections now include recommendations on anal cancer prevention for people living with HIV, who are at higher risk than the general population. Anal cancer is caused by the human papillomavirus (HPV), which triggers abnormal cell growth that can progress to invasive cancer.

 

According to the new guidelines, HIV-positive men who have sex with men and transgender women should start anal cancer screening at age 35, while other HIV-positive people should start at age 45. This should include symptom assessment and a digital anal-rectal exam; those with abnormalities should receive follow-up evaluation. The screening algorithm includes recommendations for anal cytology (Pap tests) and testing for high-risk HPV types if high-resolution anoscopy (HRA)—a technique that uses a magnifying scope to examine the anal canal—is available.

 

The new recommendation is supported by evidence from the ANCHOR study, which showed that screening HIV-positive men and women ages 35 and older for pre-cancerous lesions and treating them promptly lowered the risk of progression to anal cancer by more than half. A recent study that compared anal screening strategies for people with HIV found that combining cytology and high-risk HPV testing was more effective than either method alone and reduced the need for follow-up HRA evaluation, which is limited due to a shortage of trained providers. A recent analysis estimated that over 400,000 HIV-positive people may have abnormal anal cytology, but more than a third have no access to follow-up HRA.

 

“We need better screening strategies and potentially additional biomarkers to identify people who are at the highest risk, because the infrastructure is just so dire,” says Michael Gaisa, MD, PhD, of the Icahn School of Medicine at Mount Sinai.

 

While screening and prompt treatment can prevent progression to anal cancer, HPV vaccination can prevent infection in the first place. The CDC recommends the Gardasil 9 vaccine for girls and boys at ages 11 or 12, with catch-up vaccination through age 26, but the Food and Drug Administration has approved it for people up to age 45. Yet men who have sex with men are missing out on vaccination. A recent study found that more than half of HIV-positive and HIV-negative gay men in San Francisco had not received an HPV vaccine, often because they were too old. The researchers suggest that guidelines should be changed to recommend HPV vaccination for gay and bisexual men of all ages.