P195 All-Wales basal cell carcinoma reaudit 2024/25: assessing compliance and outcomes in secondary care dermatology

Abstract

Basal cell carcinoma (BCC) is the most common malignancy in White populations, with a rising incidence and significant cost burden in Wales. This reaudit was done to assess BCC management in Welsh secondary care dermatology against the BAD guidelines 2021. The first audit was done in 2013 [Chin MF, Katugampola RP. An audit of the management of basal cell carcinoma in Wales, the U.K. J Am Acad Dermatol 2015; 72 (5 Suppl. 1): AB95]. In a retrospective review we collected data from the first 20 cases of BCC under each consultant from 2024, across all five Welsh Health Boards, encompassing 512 histologically confirmed cases treated under dermatology. The overall complete excision rate was 83.4% as per the 2021 guidelines, falling below the 95% guideline target. However, when applying the 2013 audit criteria [incomplete excision only encompassed histologically involved margins (0 mm), not close margins (≤ 1 mm)], complete excision rates were 94.1%. Compliance with recommended surgical margins (4 mm) was 69.1% for low-risk BCCs but only 6.0% for high-risk BCCs (≥ 5-mm margins). High-risk BCCs had a 28.4% incomplete excision rate, compared with 9.0% for low-risk lesions. Infiltrative histological subtypes demonstrated higher incomplete excision rates, particularly in H-zone locations. Documentation, notably for perineural invasion, significantly improved since the 2013 audit (77.1% vs. 25.2%). Significant opportunities exist to improve BCC complete excision rates in Wales. Recommendations include tailoring margin selection based on multiple risk factors (i.e. wider margins for infiltrative BCCs and high-risk sites), considering Mohs micrographic surgery for high-risk or recurrent cases, and continued documentation improvement. A reaudit in 2–3 years is advised to assess progress.