A NEW PARADIGM FOR FOLLOW-UP OF MEN WITH ANAL SQUAMOUS CELL CANCER (ASCC)

Introduction ASCC is the commonest non-AIDS defining cancer in HIV-positive men who have sex with men, with incidence rates of u003e100 cases/100,000. Five-year survival rates (65%) are closely related to tumour size at time of diagnosis. Post treatment local recurrence is common (33% of cases). Current follow-up protocols for local recurrence of ASCC are naked eye inspection and digital anorectal examination. Anal cytology and High Resolution Anoscopy (HRA) have been proposed as additional methods, as they have the ability to detect microscopic evidence of HPV-related lesions. We report findings following diagnosis of ASCC from a single hospital. Methods Patients with ASCC who had at least one anal cytology test and/or HRA following initial diagnosis from 2001 to 2015 were identified. The HRA procedure includes an intra-anal swab for intraepithelial cytology, together with directly visualised HRA-guided anal biopsies for histopathology. Results All 14 cases (13 intra-anal; 1 peri-anal) were male, with a mean age 56 years (44 to 68) at diagnosis, and 93% were HIV positive. Typical ASCC treatment was chemo-radiotherapy (86%). Two patients had follow up anal cytology/HRA but had not received treatment for their ASCC at time of analysis. The first HRA following treatment was at a median of 9 months (range 2–48) and median follow-up after treatment was 24 months (range 2–72); with subsequent HRA follow up at  6–12 month intervals. The most significant cytology/histology findings at follow-up were high-grade squamous intra-epithelial lesions (HSIL - 36%), low grade squamous intra-epithelial lesions (50%), and 14% completely negative. None had cytological or histological evidence of local ASCC recurrence. Conclusion The use of anal cytology and HRA permit early identification of anal HPV-associated lesions, including HSIL. This has the potential to target those most at risk of ASCC recurrence. Further experience is needed to fully evaluate their role in long-term management. Disclosure of interest statement No pharmaceutical grants were received in the development of this study.