Preventing cancer Down Under: Australian screening guidelines for prevention of anal cancer in people living with HIV: the pathologists' viewpoint.

Anal squamous cell carcinoma (ASCC) is a human papillomavirus (HPV)-associated cancer with a rising incidence. People living with human immunodeficiency virus (PLHIV) are at the highest risk. Recent evidence has shown that treatment of the precursor lesion, high-grade squamous intraepithelial lesion (HSIL), can prevent cancer development. Consequently, several countries have published screening guidelines for anal HSIL as a strategy to decrease cancer incidence. In Australia, the Australasian Society for HIV, Viral Hepatitis and Sexual Health Medicine (ASHM) has recently released guidelines for PLHIV, based on HPV testing and genotyping, with liquid-based cytology (LBC) used as a triage tool for those testing positive to high-risk HPV. The pathologist's role will be critical to the success of this endeavour. This article describes the scientific basis for the recommended screening algorithm. The key features of each testing component are outlined, including anal swab collection, biopsy interpretation and the importance of relevant clinical information, to enhance communication between pathologist and clinician. Future developments are discussed, including the possibility of extension of the benefits of such screening to other at-risk groups.