Comparing and contrasting clinical consensus and guidelines for anal intraepithelial neoplasia in different geographical regions.

Anal Squamous Cell Carcinoma (ASCC) is an uncommon cancer with a recognised precursor Anal Intraepithelial Neoplasia (AIN). Although there are consistent evidence-based guidelines for the management of ASCC, historically this has not been the case for AIN and as a result there have been geographical variations in the recommendations for the treatment of AIN. More recently there have been updates in the literature to the recommendations for the management of AIN. To assess whether we are now closer to achieving an international consensus, we have completed a systematic scoping review of available guidelines for the screening, treatment and follow-up of AIN as a precursor to ASCC. MEDLINE and EMBASE were systematically searched for available clinical guidelines endorsed by a recognised clinical society that included recommendations on either the screening, treatment or follow-up of AIN. Nine clinical guidelines from three geographical areas were included. The most recent guidelines agreed that screening for AIN in high-risk patients and follow-up after treatment was necessary but there was less consensus on the modality of screening. Six Guidelines recommended the treatment of high-grade AIN and four guidelines describe a follow-up protocol of patients diagnosed with AIN. There appears to be increasing consensus on the treatment and follow-up of patients despite a poor evidence base. There is still significant discrepancy in guidance on the method to identify patients at risk of ASCC and AIN despite consensus between geographical regions on which patient subgroups are at the highest risk.