Outcomes of invasive melanoma of the head and neck treated with Mohs Micrographic Surgery – a multicenter study
Background: There are no randomized controlled trials to guide surgical margins for invasive head and neck (H&N) melanoma using conventional excision (CE). Mohs Micrographic Surgery (MMS) has shown improved local recurrence rates and survival for invasive H&N melanomas. Objective: Determine local, nodal, and distant recurrence rates (LR, NR, DR respectively), and disease-specific survival (DSS) for invasive melanoma of the head and neck treated with MMS. Methods: A retrospective multicenter study of 785 cases of invasive H&N melanoma treated with MMS using frozen sections with MART-1 immunohistochemical staining was performed to evaluate long-term outcomes over 12-years. Results: 785 melanomas (thickness 0.3mm-8.5mm) were treated with MMS. LR, NR, and DR rates were 0.51% (4/785), 1.0% (8/785), and 1.1% (9/785) respectively. For T1, T2, T3 and T4 tumors LR was 0.16% (1/636), 1.18% (1/85), 2.22% (1/45), and 5.26% (1/19), respectively. Five and 10-year DSS were 96.8% (95%CI 95.0%-98.5%) and 93.4% (95%CI 88.5%-98.3%). Limitations: A non-randomized retrospective study. Conclusion: MMS achieves significant improvements in local recurrence compared to a meta-analysis of historical cohorts of patients treated with CE. MMS should be considered an important surgical option for invasive head and neck melanoma.