Geographical Variations Impact Anal Cancer Risk for People with HIV in the US
A recent study from the Hollings Cancer Center at the Medical University of South Carolina (MUSC) indicates that the geographic region a person with HIV resides in significantly affects their risk of developing anal cancer.
Such research will provide valuable insights that influence future screening guidelines and public health initiatives, potentially giving the U.S. Preventive Services Task Force the information it needs to issue guidelines for anal cancer screening.
Discrepancies in Anal Cancer Risk Across the Country
The study, led by Ashish A. Deshmukh, Ph.D., co-leader of the Cancer Control Research Program at MUSC Hollings Cancer Center, followed a cohort of over 110,000 people to quantify geographic discrepancies in cancer risk – particularly for individuals with HIV and men who have sex with men with HIV.
It elucidated massive geographic disparities in anal cancer risk, associating these disparities with opportunistic illnesses and co-morbidities, such as diabetes, chronic kidney disease, and cardiovascular disease. The presence of such co-morbidities might encourage the human papillomavirus (HPV) – which causes almost all anal cancer cases – to proliferate and lead to cancerous developments.
The data shows that even though individuals with HIV are at a greater risk of developing anal cancer compared to those without HIV, regardless of location, the relative risk does fluctuate across the U.S. The risk, for instance, is comparatively higher for individuals with HIV located in the Midwest or South than those in the West or Northeast.
“In the Northeast, the risk for people with HIV compared to people without HIV is 16-fold higher,” stated Dr. Deshmukh. “But for people with HIV in the Midwest, the risk escalates to almost 47.5-fold, reaching nearly 100-fold for men who have sex with men with HIV.”
Toward Broader Interpretations of the Results
Dr. Deshmukh stressed that while the study exposes disparities and underlines probable key risk factors, it does not attempt to pinpoint the exact reasoning behind these differences. Yet it does pave the way for future investigations into the causes that underlie the observed disparities.
Notably, anal cancer screening rates in the Northeast and West are somewhat higher than in other regions. New York, for example, remains the only U.S. state with established guidelines for anal cancer screening – an anomaly given the generally low frequency of this cancer in the general population and the lack of nationwide guidelines.
The Role of Future Guidelines
This study also underscores the importance of considering other essential risk factors in shaping future directives for disease screening. A patient’s history of opportunistic illnesses or an AIDS diagnosis, indicated by a CD4 T-cell count below 200, might be crucial factors that should be taken into account.
These findings, demonstrating both the higher risk for HIV-positive individuals and the geographical differences in risk, could support a revision of the U.S. Preventive Services Task Force’s stance on anal cancer screening. As it stands, the task force has previously stated that there is insufficient information about the benefits and risks of anal cancer screening to issue clear guidelines.
Hopes are high that as more data becomes available on the potential harms and benefits of anal cancer screening, this issue will be reevaluated for the benefit of those at risk. With targeted, well-informed screening guidelines in place, the lasting impacts of geographical disparities on anal cancer risk could be significantly mitigated.
