Head and Neck Cutaneous Melanoma: Is Reduced Radial Margin of Excision Safe?

Introduction: It is often challenging to achieve recommended excision margins in head and neck cutaneous melanoma (HNCM). This study assessed the impact of reduced radial excision margins on disease-specific survival (DSS), disease-free survival (DFS), and local recurrence-free survival (LRFS) in these patients. Given ongoing uncertainty regarding optimal margin width for melanomas ≥1 mm, a secondary contemporary margin-based analysis was performed. Methods: This population-based study included patients diagnosed with HNCM in Manitoba, Canada, between 1970 and 2020. Radial excision margins were classified as "recommended" or "reduced" according to National Comprehensive Cancer Network guidelines. A secondary analysis compared outcomes between narrower (∼1 cm) and wider (∼2 cm) excision margins in patients with Breslow thickness ≥1.0 mm. Survival outcomes were evaluated using Kaplan-Meier analysis and multivariable Cox proportional hazards models. Results: A total of 716 patients met inclusion criteria; 177 had recommended margins and 539 had reduced margins. Patients in the reduced-margin group had thicker tumors (2.36 vs 1.72 mm, p = .007) and fewer Stage I melanomas (58.6% vs 78%, p < .001). Local recurrence occurred in 4.3% of reduced-margin and 6.2% of recommended-margin patients. Kaplan-Meier analysis showed no differences in DSS, DFS, or LRFS. On multivariable analysis, margin status was not an independent predictor of survival, whereas advanced stage and scalp location were associated with worse outcomes. In the secondary margin-based analysis, margin width was not independently associated with DSS, DFS, or LRFS. Conclusion: Reduced radial excision margins were not associated with inferior oncologic outcomes in HNCM. These findings support the oncologic safety of selective margin reduction in appropriately selected patients.