Association of Mohs Micrographic Surgery vs Wide Local Excision With Overall Survival Outcomes for Patients With Melanoma of the Trunk and Extremities

Question  Is Mohs micrographic surgery vs wide local excision associated with improved overall survival for trunk and extremity (T&E) melanomas?

Findings  This cohort study of 188 862 cases of in situ and invasive T&E melanomas from the National Cancer Database between 2004 and 2015 did not demonstrate a difference in overall survival among T&E melanomas treated with Mohs micrographic surgery vs wide local excision.

Meaning  Mohs micrographic surgery may be considered a reasonable treatment option for select T&E melanomas; the absence of a survival benefit for Mohs micrographic surgery supports current US practice patterns, where wide local excision is the predominant treatment for T&E melanomas.

Importance  Although previous database studies suggest that Mohs micrographic surgery (MMS) treatment is associated with improved overall survival (OS) for head and neck melanomas, outcomes for trunk and extremity (T&E) tumors have not been adequately evaluated.

Objective  To assess survival outcomes for patients with melanomas of the T&E treated with MMS vs wide local excision (WLE).

Design, Setting, and Participants  This retrospective cohort study examined deidentified data from the National Cancer Database between 2004 and 2015. Inclusion criteria for the analysis included diagnosis of trunk, upper extremity, or lower extremity melanoma; known Breslow depth; removal by MMS or WLE; and known last date of survival status.

Main Outcomes and Measures  Five-year all-cause mortality (ACM) rates.

Results  A total of 188 862 in situ and invasive melanomas were included in the analysis (MMS, 2.3%; WLE, 97.7%); the mean (SD) age of patients included was 58.8 (16.0) years, and 52.7% were male. Multivariate analysis demonstrated no OS difference among trunk (WLE hazard ratio [HR], 1.097; 95% CI, 0.950-1.267; P = .21), upper extremity (WLE HR, 1.013; 95% CI, 0.872-1.176; P = .87), lower extremity (WLE HR, 0.934; 95% CI, 0.770-1.134; P = .49), or combined T&E (WLE HR, 1.031; 95% CI, 0.941-1.130; P = .51) tumors. Factors associated with increased risk of ACM on multivariate analysis of all tumors included increasing age (HR, 1.043; 95% CI, 1.042-1.044; P < .001), no insurance or nonprivate insurance (none: HR, 1.921 [95% CI, 1.782-2.071]; Medicaid: HR, 2.410 [95% CI, 2.242-2.591]; Medicare: HR, 1.237 [95% CI, 1.194-1.281]; other government insurance: HR, 1.279 [95% CI, 1.117-1.465]; P < .001 for all), positive surgical margins (HR, 1.609; 95% CI, 1.512-1.712; P < .001), a Charlson-Deyo comorbidity score greater than 0 (Charlson-Deyo score of 1: HR, 1.340; 95% CI, 1.295-1.385; P < .001; Charlson-Deyo score of ≥2: HR, 2.044; 95% CI, 1.934-2.159; P < .001), tumor ulceration (HR, 2.175; 95% CI, 2.114-2.238; P < .001), and increasing Breslow depth (HR, 1.002 [per 0.1 mm]; P < .001). Female sex (HR, 0.698; 95% CI, 0.680-0.716; P < .001) and nonnodular subtype (lentigo maligna/lentigo maligna melanoma: HR, 0.743; 95% CI, 0.686-0.805; P < .001; superficial spreading: HR, 0.739; 95% CI, 0.710-0.769; P < .001; other subtype: HR, 0.817; 95% CI, 0.790-0.845; P < .001; nodular: HR, 1 [reference]) were associated with improved OS.

Conclusions and Relevance  This cohort study of patients surgically treated for melanomas of the trunk and/or extremities found that, compared with WLE, MMS was not associated with significantly different OS for T&E melanomas.