Faber MT, et al. - Researchers used data from nationwide, population-based Danish registries to determine the risk of anal cancer after a diagnosis of benign anal disease and anal high-grade intraepithelial neoplasia (AIN). They observed 126,174 people with either non-neoplastic anal disease or AIN 1 to 3 until the first occasion of anal cancer. They used the Danish HIV Cohort Study to collect data on HIV status. Findings revealed an increase in the risk of anal cancer with increasing severity of lesions, approaching 4% 5 years following diagnosis of AIN3. A significantly higher anal cancer risk was seen even in those with non-neoplastic anal lesions, especially inflammatory lesions, compared with that expected from Danish national anal cancer rates. Particularly, HIV-positive individuals exhibited a high risk of anal cancer.