DS26 Recurrence and histological adequacy of cutaneous squamous cell carcinoma on the head and neck treated with triple curettage and cautery: a 5-year retrospective review

Abstract Triple curettage and cautery (C&C) is widely used for the treatment of cutaneous squamous cell carcinoma (cSCC), particularly in older patients or those unsuitable for surgical excision. The 2020 British Association of Dermatologists guidelines recommend C&C for immunocompetent individuals with small (< 1-cm), well-defined, nonrecurrent and clinically low-risk cSCC. However, concerns remain regarding the effectiveness and the adequacy of histological assessment in confirming complete tumour removal. This audit evaluates the recurrence rate and histological adequacy of cSCC treated with triple C&C on the head and neck over a 5-year period. A retrospective audit identified 1387 patients diagnosed with cSCC between March 2019 and July 2024, of whom 139 met the inclusion criteria of having cSCC on the head or neck treated with triple C&C. The cohort had a mean age of 81.8 years, with 106 male patients. The most common tumour sites were the scalp (n = 57), forehead (n = 18) and temple (n = 16), with lesion sizes ranging from 3 mm to 20 mm (mean 8.7 mm). Histopathological analysis classified 78 tumours as well differentiated, 34 as moderately differentiated and four as poorly differentiated. Pathological staging was available for 122 specimens, all documented as pT1. Specimen adequacy was commented on in 24 reports, with 12 citing superficial sampling that hindered assessment and 12 noting fragmentation that compromised evaluation. Following histopathological review and multidisciplinary team discussion, 29 patients underwent further excision. Recurrence occurred in eight cases out of 139 (5.8%), with the mean time to recurrence being 12.6 months. Six recurrences occurred on the scalp, and seven were initially classified as low risk and staged as pT1 (no pathological staging data for one). At the time of primary diagnosis, two tumours were moderately differentiated, while six were well differentiated. Upon recurrence, three remained pT1, two progressed to pT2 and three progressed to pT3. Four recurrent tumours were well differentiated and four were moderately differentiated, with two exhibiting perineural invasion, requiring adjuvant radiotherapy. One patient developed distant metastases and subsequently died. Follow-up data were available for an average of 2.6 years (range 23 weeks to 5 years and 8 months), during which 43 patients died, one from metastatic cSCC. Complications from triple C&C were rare, with only two patients experiencing issues (nonhealing wound and cartilage exposure requiring additional surgery). Literature-reported recurrence rates for triple C&C range from 1.3% to 7%, comparable with surgical excision (4–8%). However, patients undergoing triple C&C are typically older and multimorbid, reflected by the 31% mortality rate during follow-up. Notably, > 20% required subsequent excision due to histological concerns, underscoring the limitations of this technique. While triple C&C may be suitable for selected low-risk tumours, its histological limitations warrant caution, and careful patient selection remains critical.