A NEW study presented at the International AIDS Conference in Munich found that combining anal cytology with high-risk human papillomavirus (HPV) testing offers a more effective approach to detecting anal cancers in people living with HIV. The research, led by Michael Gaisa, Icahn School of Medicine at Mount Sinai, US, compared five different screening strategies outlined by the International Anal Neoplasia Society. These strategies ranged from using anal cytology or high-risk HPV testing alone to various combinations of both methods.
The study found that the combination of high-risk HPV testing with cytology triage had the most balanced performance, with an acceptable sensitivity of 85%, the highest specificity at 48%, and the greatest positive predictive value at 54%. This approach resulted in the lowest rate of referrals for high-resolution anoscopy at 66%. Additionally, Gaisa noted that while high-risk HPV testing alone showed the highest sensitivity (96%) and negative predictive value (92%), it also led to the highest number of referrals for high-resolution anoscopy, with 83% of patients being referred. In contrast, cytology alone led to a 77% referral rate.
The findings underscore the potential of the combined anal cytology and HPV testing approach to optimise screening efficiency, particularly in high-resource settings where the capacity for anal cancer screening is often constrained. This could help streamline the use of diagnostic tools like high-resolution anoscopy, which are vital but scarce, especially in resource-limited settings. “Screening strategies that incorporate both anal cytology and high-risk HPV testing can enhance specificity without sacrificing sensitivity, making them a more efficient option in settings with limited diagnostic resources,” Dr. Gaisa explained.
The study also highlighted the significant risk of HPV-associated anal cancer in people with HIV, particularly among older men who have sex with men and transgender women. The annual incidence of anal cancer in these groups can be as high as 100 per 100,000 person-years, compared to just 1.7 per 100,000 person-years in the general population.
In summary, this combined method not only improves the accuracy of anal cancer detection but also significantly reduces the need for high-resolution anoscopy referrals, which are often limited and costly. Gaisa and his team emphasised the urgent need for improved screening infrastructure, especially in middle- and low-income countries where resources are even more constrained.
Laith Gergi, EMJ
Reference
Gaisa M et al. The effectiveness of different anal cancer screening strategies for people living with HIV/AIDS. Abstract OAB0102. IAC Annual Congress, 22-26 July, 2024.
