Managing Closely Excised Nonmelanoma Skin Cancer

The aim of nonmelanoma skin cancer (NMSC) excision is histologic clearance with margins of ≥1 mm, but evidence for close-margin management is scarce.

To compare complete, close, and incomplete excision recurrences.

We performed a retrospective study of a subset of patients who underwent NMSC excision during 2020 to 2021. Lesions were grouped as complete (≥1 mm clearance), close (<1 mm), or incomplete (involved) and recurrence data were collected. Discrete data were analyzed using a χ² test.

There were 421 lesions comprising 194 squamous cell carcinomas (SCCs; 49%) and 227 basal cell carcinomas (BCCs; 51%) included in the analysis. The mean follow-up was 29.3 months (standard deviation: 3.2), and the recurrence rate was 5%. There was a significantly greater risk of recurrence in closely (12%) vs completely (3%) excised SCCs (χ²=4.71; degrees of freedom [df]=1; P=0.03); however, no difference was demonstrated between close (12%) and incompletely (12%) excised SCCs (χ²<0.05; df=1; P=0.98). There was no statistical difference in recurrence rates between completely (1%) and closely (3%) excised BCCs (χ²=1.08; df=1; P=0.30), but a difference was found between closely (3%) and incompletely (16%) excised BCCs (χ²=6.33; df=1; P=0.01).

Follow-up was <5 years, after which NMSCs may still recur.

Our results support the clinical practice of treating closely excised SCCs as incomplete and treating closely excised BCCs as complete, perhaps with a follow-up period, in select cases such as when satisfying patient preference or minimising morbidity due to re-excision.