Anal cancer incidence and burden among US men: New study models groups at greatest risk

A new breakdown of the estimated incidence of anal cancer among U.S. men—which stratified risk by age, HIV status, and sexual orientation—offers an opportunity to fine-tune the prioritization of anal cancer screenings.

About This Study

“Human papillomavirus-associated anal cancer incidence and burden among US men, according to sexual orientation, HIV status, and age” was published online on April 5, 2023, in Clinical Infectious Diseases. The lead author is Ashish A. Deshmukh, Ph.D., M.P.H., of the Department of Public Health Sciences at the Hollings Cancer Center of the Medical University of South Carolina.

Key Research Findings

The aim of this research was to combine statistics from many data sources to develop a mathematical model estimating anal cancer rates among men in the US by sexual orientation, HIV status, and age. It covered only squamous cell carcinoma of the anus, a human papillomavirus (HPV)-associated cancer. Data spanned the years 2011 to 2016.

Among HIV-negative men who have sex with men (MSM), anal cancer incidence rose significantly with age, reaching 34 cases per 100,000 men at age 60 or above. Among HIV-negative men who have sex with women (MSW), the incidence was fewer than 3 cases per 100,000 men at all ages.

MSM living with HIV acquired anal cancer at a younger age (98% of all anal cancers in men under 30 were within that group), while among HIV-negative MSW, anal cancer was more common in older men (67% of cancers in men 60 and older were among that group).

Overall, 54% of all anal cancer incidence occurred in HIV-negative MSW, 19% occurred in HIV-negative MSM, and 27% occurred in men living with HIV (independent of sexual orientation). However, the authors noted that population sizes in these groups differ significantly; they also suggested that distribution will likely change as HIV prevention improves and people continue to live longer with the virus.

Discussion Highlights and Implications for Practice

The study authors believe that the information provided by this new model can “help raise awareness, drive investment cases, and inform recommendations.” They noted, for instance, that older men generally have not been vaccinated against HPV and that vaccination campaigns among young women are unlikely to benefit prevention in MSM. Hence, secondary cancer prevention through screening and early treatment is needed, they urged.

Additionally, while the findings could inform screening recommendations, cost-benefit ratios and other data are needed to determine when to start anal swabs in HIV-negative men, the authors wrote.

By Barbara Jungwirth