Recurrence rates of cutaneous squamous cell carcinoma of the head and neck after Mohs micrographic surgery vs. standard excision
A retrospective cohort study
Background: Recurrent cutaneous squamous cell carcinoma (cSCC) has been associated with an increased risk of local functional and aesthetic comorbidity, metastasis and mortality. Objectives: To compare the risk of recurrence between Mohs micrographic surgery (MMS) and standard excision for cSCC of the head and neck. Methods: This was a retrospective cohort study of all patients with a cSCC treated with MMS or standard excision at the departments of dermatology of a secondary or tertiary care hospital in the Netherlands between 2003 and 2012. To detect all recurrences, patients were linked to the Dutch pathology registry. To compare the risk of recurrence between MMS and standard excision, hazard ratios (HRs) were used adjusted for clinical tumour size > 2 cm and deep tumour invasion. Results: A total of 579 patients with 672 cSCCs were included: 380 cSCCs were treated with MMS and 292 with standard excision. The risk of recurrence was 8% (22 of 292) after standard excision during a median follow-up of 5·7 years [interquartile range (IQR) 3·5–7·8], which was higher than the 3% (12 of 380) after MMS during a median follow-up of 4·9 years (IQR 2·3–6·0). The cumulative incidence of recurrence was higher for standard excision than for MMS during the entire follow-up period of 8·6 years. Carcinomas treated with MMS were at a three times lower risk of recurrence than those treated with standard excision when adjusted for tumour size and deep tumour invasion (adjusted HR 0·31, 95% confidence interval 0·12–0·66). Conclusions: MMS might be superior to standard excision for cSCCs of the head and neck because of a lower rate of recurrence.