The Impact of Pathological Margins on Basal Cell Carcinoma Recurrence: Does a Millimetre Matter?

Background Basal cell carcinoma (BCC) is the most common skin malignancy worldwide. Existing studies on histopathological margins and recurrence have lacked long-term follow-up and histopathological confirmation, leaving no clear consensus on the optimal margin to minimise recurrence, particularly in the UK population. Objectives This study aimed to evaluate the impact of histopathological margin width on BCC recurrence rates. Specifically, it sought to compare recurrence rates between lesions excised with ≤1 mm and >1 mm margins, assess recurrence patterns over a seven-year follow-up period, and determine whether wider margins had reduced the recurrence risk sufficiently to influence surgical guidelines and multidisciplinary team (MDT) discussions. Methods The Trust histopathology database was analysed to identify all patients with a histological diagnosis of BCC over a two-year period (January 2005 to December 2006). Histopathology reports for these patients were reviewed, and data on patient demographics, lesion site, BCC subtype, and histopathological margins were recorded, along with recurrence details over the subsequent seven years (January 2005 to December 2013). Results Of the 3,551 histopathology reports identified, complete records were available for 965 lesions. Pathological margins of ≤1 mm had been recorded in 269 lesions (narrow margin group), while 696 lesions had margins >1 mm (wide margin group). A total of 13 recurrences (4.8%) occurred in the narrow margin group compared to 14 recurrences (2.0%) in the wide margin group, showing a statistically significant difference (p = 0.017). The anatomical site of the BCC did not significantly impact recurrence, and BCC subtype was not a major determinant, with most subtypes showing no statistically significant association. Conclusion BCC recurrence can be influenced by several factors, including tumour location and size, histological subtype, patient immunosuppression, and follow-up limitations. Our findings confirm that achieving histopathological margins greater than 1 mm during BCC excision reduces the recurrence risk by more than half compared to excisions with ≤1 mm margins. Further research is needed to validate the factors contributing to recurrence, ensuring evidence-based surgical guidelines, MDT discussions, and optimal patient care for BCC management.