BackgroundThe use of Mohs micrographic surgery (MMS) in melanoma treatment has divided opinion and evidence‐based guidelines are lacking.ObjectivesThis systematic review aimed to analyse clinical outcomes for patients with invasive melanomas treated with Mohs rather than wide local excision (WLE).MethodsEmbase, MEDLINE and Cochrane databases (to 30 August 2023) were searched for studies using Mohs to treat invasive melanoma. Outcomes of interest were local recurrence and death from melanoma.ResultsThirty‐five articles involving 41,499 patients with invasive melanoma treated with Mohs were identified. Sixteen studies compared Mohs with WLE and 19 were Mohs‐only, non‐comparative studies. Patients treated with Mohs differed significantly from those undergoing WLE, in particular Mohs patients were older and had thinner melanomas. Two comparative studies using the same data source reported adjusted hazard ratios for melanoma‐specific death and both showed no significant difference between Mohs and WLE‐treated patients; 0.87 (95% CI 0.55–1.35) and 1.20 (95% CI 0.71–20.36). There was also no statistically significant difference in local recurrence risk; the unadjusted risk ratio for patients treated with Mohs was 0.46 (95% CI 0.14–1.51 p = 0.20) with moderate heterogeneity (I2 = 62%). No studies reported multivariable analyses for risk of local recurrence. Many studies generated from relatively few and often overlapping data sets have reported the use of Mohs to treat patients with invasive melanoma. Fewer studies were comparative between Mohs and WLE and these reported substantially different baseline risks of recurrence and death from melanoma between the groups. Mohs has generally been used for thinner melanomas in older patients; therefore, comparisons based on univariable analyses are likely to have been misleading.ConclusionsOn the basis of currently available data, it is not possible to reliably assess whether outcomes differ if invasive melanomas with comparable features are treated with Mohs or WLE, and randomized trial evidence will be required for reliable conclusions to be reached.
