Anal cancer is one of the most significant and underrecognized cancer risks facing Americans living with HIV — and the tools to prevent and detect it at its most treatable stage already exist.
A new CIDRAP analysis published July 1, 2026 confirms what HIV specialists have known for years but has not been communicated clearly enough to the patients who need to act on it: people whose HIV is not well controlled face 8.6 times the risk of developing HPV-related anal cancer compared to those without HIV. And even people with well-controlled HIV face a risk 3.9 times higher than average.
Anal cancer is driven by the human papillomavirus — specifically HPV type 16, which is also responsible for the majority of cervical cancers. In people with HIV, the immune suppression that defines the condition reduces the body's ability to clear HPV infections, allowing them to persist and progress to precancerous and then cancerous lesions at a significantly elevated rate.
Why This Matters
The scale of this risk has been directly compared to the pre-Pap-smear burden of cervical cancer in women. Clinicians note that anal cancer risk in high-risk groups — particularly men who have sex with men living with HIV — has surpassed the level of cervical cancer risk in women before Pap smear screening was widely adopted. That comparison is not made lightly: it is meant to convey the scale of a preventable cancer burden that currently receives far less clinical attention than the well-established cervical cancer screening system.
According to CIDRAP's reporting, anal cancer incidence among HIV-positive men who have sex with men has been estimated at approximately 131 per 100,000 person-years — compared to approximately 1.8 per 100,000 in the general population. Among men without HIV who have sex with men, the rate is 32 per 100,000.
Yet anal cancer screening has not been adopted at nearly the same scale or consistency as cervical cancer screening, despite the existence of equivalent screening tools (anal Pap tests) and the same known prevention approaches (HPV vaccination).
What We Know So Far
Three distinct, evidence-based interventions can reduce anal cancer risk in HIV-positive patients:
HPV vaccination. The FDA has approved Merck's Gardasil 9 specifically to prevent anal cancer, in addition to cervical and other HPV-related cancers. In a randomized trial of men who have sex with men, vaccinating boys and young men against HPV before age 26 reduced the risk of anal precancers by 75% compared to unvaccinated men. Real-world analysis suggests approximately 50 percent reduction in actual practice. Gardasil 9 is approved for use in people aged 9 to 26; adults up to age 45 may receive the vaccine after discussing benefits and risks with a health care provider.
Anal Pap testing. Anal cancer screening uses the same general principle as cervical cancer screening: a provider uses a swab to test for HPV and performs an anal Pap test, collecting cells for microscopic examination. If abnormal cells are found, clinicians perform a procedure called high-resolution anoscopy (HRA) to examine the anal canal in more detail and take tissue samples if needed.
Treatment of precancerous lesions. The landmark ANCHOR trial, published in the New England Journal of Medicine, found that screening and treating anal precancers in people with HIV reduced the risk that the growths would become cancerous by 57%. This is directly analogous to the colposcopy and LEEP procedure system used to treat cervical precancers — and the logic is identical: catch it early, treat it, prevent cancer.
Where the Risk Is Highest
The highest-risk group is HIV-positive men who have sex with men, followed by HIV-positive women, heterosexual HIV-positive men, HIV-negative men who have sex with men, and women with a history of cervical precancer or cancer. However, people with HIV across all risk categories face a substantially elevated anal cancer risk compared to the general population, and any HIV-positive patient who has never been screened should ask their provider about their screening status.
What Doctors and Experts Say
"I'm a huge fan of the HPV vaccine," George Froehle, a physician assistant and HIV specialist at the Aliveness Project, an HIV clinic in Minneapolis, told CIDRAP. Froehle emphasized that both HPV vaccination and anal cancer screening are currently underutilized even in HIV care settings specifically designed to manage these patients' health comprehensively.
The New York State Department of Health's HIV Guidelines recommend beginning anal cancer screening at age 35 for people living with HIV, regardless of other risk factors. The International Anal Neoplasia Society (IANS) similarly recommends beginning screening at 35 for people living with HIV and performing screening more frequently than in the general population, because longer screening intervals appropriate for general populations are insufficient for people with HIV.
What the Evidence Shows — and What It Does Not
The evidence from the ANCHOR trial demonstrating a 57% risk reduction from treating anal precancers is particularly significant because it directly addresses a question that had been debated: whether treating precancerous lesions actually prevents cancer, or whether aggressive treatment of lesions that might not progress was unnecessarily invasive. The ANCHOR results confirm the benefit of the screen-and-treat approach, similar to the established logic behind Pap testing and cervical cancer screening.
What the evidence does not currently include is a widely established national guideline with the same institutional authority as cervical cancer screening recommendations. Implementation of anal cancer screening remains inconsistent across HIV care settings.
Who Should Be Asking Their Doctor About This Right Now
- All HIV-positive adults who have never been screened for anal cancer or HPV-related anal lesions
- HIV-positive men who have sex with men, who face the highest absolute risk
- HIV-positive people of any gender who have not received HPV vaccination
- Any HIV-positive person aged 9 to 45 who wants to discuss HPV vaccination with their provider
- HIV-positive individuals who have received HPV vaccination but have not had a discussion about anal cancer screening as a separate ongoing health maintenance issue
Symptoms and Warning Signs to Watch For
Anal cancer symptoms, when they occur, may include:
- Rectal bleeding
- Anal pain or pressure
- A lump or mass near the anus
- Changes in bowel habits
- Anal itching or discharge
However — as with all cancers — the goal of screening is to detect precancerous changes before symptoms appear. Do not wait for symptoms to develop before asking about screening.
What You Can Do Now
- If you are HIV-positive and have never had a conversation about anal cancer screening with your HIV care provider, schedule that conversation at your next appointment or call to request one before then.
- If you are HIV-positive and under 26 and have not received HPV vaccination, ask your provider for Gardasil 9 now.
- If you are HIV-positive and between 27 and 45, ask your provider about a shared decision conversation regarding HPV vaccination.
- If you are an HIV care provider, consider whether anal cancer screening — including anal Pap testing and referral to high-resolution anoscopy when indicated — is part of your practice's standard health maintenance protocol for HIV-positive patients.
Cost and Access: What Patients Should Know
Gardasil 9 is covered under the ACA's preventive services mandate for individuals under 26. Adults between 27 and 45 may face variable coverage — check with your insurer. HIV care settings, including Ryan White-funded clinics, may cover HPV vaccination and anal cancer screening. Anal Pap testing and HRA are generally covered when ordered as part of HIV medical care, though coverage may vary by plan.
The Bottom Line
HIV raises anal cancer risk by 8.6 times when not well controlled, and 3.9 times even with good control. This is a preventable cancer with a 57% risk reduction achievable through a proven screen-and-treat approach and 75% precancer risk reduction through HPV vaccination before age 26. If you are HIV-positive and this conversation has not been part of your regular care, raise it now.
