Mohs micrographic surgery versus wide local excision for melanoma in situ: analysis of a nationwide database

With the rising incidence of melanoma in situ (MIS) or cutaneous melanoma, there is an increasing emphasis on the need to understand optimal treatment strategies. The current standard of surgical care is wide local excision (WLE). Alternative surgical techniques have been proposed including Mohs micrographic surgery (MMS). We aimed to compare survival rates following WLE versus MMS surgery for MIS.

We performed a retrospective analysis of the Surveillance, Epidemiology, and End Results (SEER) cancer registry. 24,515 cases of WLE were identified and compared with 4122 cases of MMS surgery for MIS.

There was a significantly higher proportion of elderly patients aged ≥75 years in the MMS group compared to WLE (23.3% vs. 15.3%). The proportion of females was higher for WLE compared to MMS (48.8% vs. 40%). Facial MIS tumors were significantly higher for MMS, as were scalp/neck tumors. After adjustment for confounding factors, there was no significant difference in cancer-specific survival (HR 0.928, 95% CI 0.596-1.446, P = 0.74) and overall survival (HR 1.006, 95% CI 0.896-1.129, P = 0.924).

Adjusted analyses demonstrated no differences in overall survival or cancer-specific survival between MIS patients treated with MMS compared with WLE.