MOHS micrographic surgery (MMS) showed no significant difference in five-year recurrence of primary cutaneous squamous cell carcinoma (CSCC) compared with standard excision (SE), according to a prospective multicentre cohort study. The findings provide comparative five-year recurrence data for the two surgical approaches, while also demonstrating a smaller ratio of final defect size to initial tumour size with MMS.
MMS is a tissue-sparing approach that provides complete margin control and is therefore theoretically expected to reduce recurrence. However, prospective comparisons with SE remain limited, and no randomised controlled trials have compared the approaches. In clinical practice, MMS is also more commonly selected for higher-risk tumours, particularly those affecting cosmetically sensitive sites.
The prospective cohort included patients with primary CSCC treated with MMS or SE across six centres in the Netherlands. Recurrences were identified through linkage with the Dutch Nationwide Pathology Databank. Fine and Gray competing risk regression was used to assess recurrence after adjustment for confounding factors.
Overall, 761 patients with 903 completely excised primary CSCCs were included. Of these, 629 tumours were treated with SE and 274 with MMS. Tumours managed with MMS were more frequently high stage according to American Joint Committee on Cancer 8th edition criteria, with 55% classified as at least T2 compared with 25% following SE. They were also more frequently located in the H-zone, at 77% versus 37%.
The five-year cumulative incidence of recurrence was 1.7% with SE and 3.3% with MMS. After adjustment for disease stage, the subdistribution hazard ratio for recurrence with MMS versus SE was 1.51 (95% confidence interval: 0.66–3.44; p=0.33), indicating no statistically significant difference.
The five-year cumulative incidence of metastasis was 0.8% with SE and 1.1% with MMS. The ratio of final defect size to initial tumour size was significantly smaller following MMS, at 1.2 compared with 3.0 with SE (p<0.001).
The researchers noted that the non-randomised design and limited number of events prevented definitive conclusions about whether a true difference in efficacy exists. However, the smaller defects associated with MMS support its use where preservation of tissue is particularly important, including cosmetically or functionally sensitive areas.
Reference
Eggermont CJ et al. Five-year recurrence rate of cutaneous squamous cell carcinoma after Mohs micrographic surgery versus standard excision: a prospective multicentre cohort study. Br J Dermatol. 2026;DOI: 10.1093/bjd/ljag399.
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