Examining the role of wide excision margins in pediatric melanoma: A National Cancer Database analysis.

Background: Although adult guidelines are often applied to children, age-specific surgical margins have not been defined for pediatric melanoma.

Procedure: Patients <20 years of age with invasive, cutaneous melanoma were identified using the 2004-2016 National Cancer Database and categorized as undergoing wide (>1 cm) or narrow (≤1 cm) excision. Unadjusted overall survival (OS) was compared using the Kaplan-Meier method and log-rank test. Multivariable Cox proportional hazard models were used to estimate the effect of excision margin on OS after adjustment for available covariates.

Results: In total, 2081 patients met study criteria: 1338 (64.3%) patients underwent wide excision whereas 743 (35.7%) underwent narrow excision. Unadjusted OS was improved in the narrow-excision group (log-rank p = .01), which was consistent among patients with thicker (>1 mm) and thinner (≤1 mm) tumors. After adjustment for patient and tumor characteristics, we found no evidence of a difference in OS for patients who underwent narrow excision compared to patients who underwent wide excision (adjusted hazard ratio 0.57, 95% confidence interval 0.32-1.01, p = .053). There was no interaction between excision margin width and Breslow depth (p = .85), indicating that the effect of excision margin width on OS does not differ based on Breslow depth.

Conclusions: In this analysis, wide excision (>1 cm) does not appear to be associated with improved survival in children with melanoma regardless of tumor characteristics. Although further studies are needed to define optimal excision margins in pediatric melanoma, this study suggests that more narrow margins (≤1 cm) may be acceptable.