Higher Rates of Regional Disease but Improved Outcomes in Pediatric versus Adult Melanoma

Background: Malignant melanoma is rare in the pediatric population and management is largely extrapolated from adult guidelines. Recent adult data have shown that immediate completion lymph node dissection (LND) does not improve overall survival in selected patients with clinically node negative, sentinel lymph node-positive disease. The aims of this study were to (1) compare the frequency and management of regional disease between children and adults, (2) evaluate trends in the utilization of completion LND in children and (3) determine the impact of regional disease on survival in children.

Methods: The National Cancer Database (NCDB) was queried for patients with melanoma from 2012-2017 and patients categorized as pediatric (≤18 years, n=962) or adult (n=327,987). Factors associated with completion LND in children with positive SLNB were evaluated in multivariable analysis. Kaplan-Meier survival analysis was performed.

Results: Compared to adult patients, children present with deeper primary tumors (T3 or T4 26.5% vs 15.5%, p<0.001), resulting in higher rates of nodal assessment with SLN biopsy or LND (60.2% vs 36.6%, p<0.001) and higher rates of regional nodal disease (35.1% vs 23.4%, p<0.001) in those who underwent nodal interrogation. For the entire study time period, children underwent higher rates of completion LND after SLN biopsy (10.4% vs 4.1%) and upfront LND (15.2% vs 8.7%). A decreased rate of completion LND was noted in 2017 compared to 2012 (odds ratio (OR) 0.16 (p=0.005). Predictors of completion LND in multivariable analysis included older pediatric age (>12 years, OR=1.6, p=0.037) and lower extremity primary (OR=0.29, p<0.001). Children with regional nodal disease have improved 3-year overall survival compared to adults (96.5% vs 71.0%, p<0.001), and this holds true even after excluding patients with distant metastatic disease.

Conclusion: Children with melanoma have higher rates of nodal disease but better survival than adults. As in adults, there has been a recent increase in close nodal observation rather than completion LND for patients with positive SLN. Further study of nodal surveillance for pediatric patients is warranted.