Hollings study: Concentrations of anal cancer among HIV screening-eligible populations can identify infrastructure needs

A new study led by an MUSC Hollings Cancer Center researcher identifies where anal cancer cases among people with HIV are concentrated across the United States, providing a roadmap for communities seeking to expand access to anal cancer screening and prevention.

The study was published Aug. 22 in the Journal of the National Cancer Institute. It found substantial geographic variation in the burden of anal squamous cell carcinoma (SCC) among people with HIV, with some metropolitan areas accounting for a disproportionately large share of cases. The findings could help health systems and public health agencies to determine where screening infrastructure and specialized care are most urgently needed.

“It’s a population-based study, and the objective is to quantify the burden, both at the state and metropolitan statistical area levels,” said first author Ashish Deshmukh, Ph.D., co-leader of the Cancer Prevention and Control research program at Hollings. “Our goal is to provide information that can help communities plan for the screening needs of people who are at increased risk.”

People with HIV face a substantially higher risk of anal cancer than the general population. Yet, until recently, there were no formal national recommendations for when and how to screen people with HIV for anal cancer.

That changed with the introduction of screening guidelines in 2024. The recommendations consider a person’s age, HIV status and whether high-resolution anoscopy, or HRA, a specialized procedure used to identify precancerous lesions in the anal canal, is available.

Screening typically begins with an anal Pap test, similar to the Pap smear used to screen for cervical cancer. Both anal and cervical cancers are primarily caused by the human papillomavirus (HPV). If abnormal cells are found after an anal Pap, then an HRA can be used to examine the anal canal under magnification and identify precancerous lesions that can be treated before they become cancer.

The importance of detecting and treating these lesions was demonstrated by the landmark ANCHOR trial, published in 2022, which showed that treating anal precancer in people living with HIV substantially reduced the risk of developing anal cancer. But access to HRA remains uneven. The procedure requires specialized equipment, training and expertise, and many communities do not have a provider who can perform it. A 2024 study found that about one-third of people with HIV lacked access to HRA, while another 45% would need to be referred to another facility for the procedure.

The study also found that about 20% of anal SCC diagnoses among men in the U.S. occur in men with HIV. In some areas, however, the proportion is substantially higher. For example, people with HIV accounted for about 59% of anal cancer diagnoses among men in the District of Columbia, 30% in Maryland, 29% in California and New York, 27% in Texas and 25% in Georgia.

“These findings have important cancer prevention and public health implications, as the geographic concentration of anal SCC diagnoses among people with HIV highlights the need for coordinated approaches that address both HIV and anal cancer prevention,” the study authors noted.

The study looked at larger metropolitan areas and did not have data for South Carolina – although Deshmukh and colleagues are working on another study that will.

Notably, though, MUSC Health offers both anal Pap tests and HRA testing through its Ryan White HIV Clinic.

“The big change in recent years is we have formal guidelines – which Dr. Deshmukh participated in developing – which we didn’t have historically,” said infectious diseases doctor Eric Meissner, M.D., Ph.D. “So we have formal guidelines for who, when and how to screen for anal cancer, and so it is a routine part of our discussions with our patients, in the same vein as we talk about colon cancer screening, lung cancer screening and cervical cancer screening – anal cancer screening is on that list.”

Meissner said patients agree to anal cancer screening at about the same rate that they agree to other preventive measures, whether it be vaccination, hypertension management or other cancer screenings. But he has noticed that patients are more likely to get screened now that there is an official screening guideline.

Gweneth Lazenby, M.D., performs the HRA procedure at the MUSC Ryan White HIV Clinic and has done so for almost 15 years. In that time, she has never diagnosed a case of anal cancer and has seen only a few patients with precancer.

That experience also underscores an important point: Although people living with HIV face an elevated risk, anal cancer remains relatively uncommon. Still, it is currently one of the fastest-growing cancers in terms of both new cases and mortality. More than 11,000 people in the United States are expected to be diagnosed with anal cancer this year.

While anal cancer diagnoses and deaths are continuing to rise among the general population, HPV vaccination can prevent many HPV infections that lead to cancer. At the same time, screening can identify precancerous lesions in people at higher risk and allow them to be treated before cancer develops. Emerging evidence also suggests that anal cancer rates may decline in communities where screening programs have been implemented.

By pairing this data with information on at-risk groups approaching the screening age, health agencies can plan for screening and tailor infrastructure to meet community needs.