A recent study found significant disparities in the risk of anal cancer among people with HIV and men who have sex with men with HIV, depending on the region they live in. The study, published in the Journal of the National Cancer Institute, established geographic differences in anal cancer risk and its association with opportunistic illnesses and co-morbidities such as diabetes and cardiovascular disease for people with HIV. Almost all cases of anal cancer are caused by the human papillomavirus (HPV), but there may be additional factors at play, such as inflammation, that allow HPV to cause cancer in individuals with co-morbidities.
While the relative risk of anal cancer is higher for people with HIV compared to those without HIV across the country, the study revealed variations in risk by region. The risk was found to be higher in the Midwest and South compared to the West and Northeast. For people with HIV in the Midwest, the risk was nearly 47.5-fold higher, reaching almost 100-fold higher for men who have sex with men with HIV. The study did not determine the reasons for these differences, but noted that they lay the groundwork for further research into potential causes.
Screening rates for anal cancer are higher in the Northeast and West regions, with New York state being notable for having established guidelines for anal cancer screening. Developing screening guidelines based on risk factors, such as previous opportunistic illnesses or low CD4 counts, could be beneficial in identifying individuals at higher risk for anal cancer. This study suggests that guidelines should consider these risk factors to improve early detection and management of anal cancer.
The study author hopes to see the U.S. Preventive Services Task Force develop guidelines for anal cancer screening, based on the emerging evidence on the risk-benefit balance in this population. The study emphasizes the importance of evaluating the potential harms and benefits of screening for anal cancer among people with HIV. The decline in anal cancer cases among people with HIV could be attributed to increased screening activities, but geographic disparities may persist if screening practices do not improve.
Funding for this study was provided by the National Institutes of Health and the Canadian Institutes of Health Research. The study highlights the need for further research into the causes of geographic disparities in anal cancer risk among people with HIV, and emphasizes the importance of developing screening guidelines that consider risk factors to improve early detection and management in this at-risk population.
