Abstract 3566: Mohs surgery trends in 104 cases of pediatric melanoma
Authors: Brandt Zachary G. , Wu Xinxin , Kennard Jared , Griffin Julia , Silberstein Peter 
Published: March 2024

Background: Cutaneous melanoma is rare in children with a global incidence of two to five cases per million people per year, accounting for roughly 1% of all pediatric malignancies.5 However, the incidence of pediatric melanoma in the United States is increasing.1 Mohs Micrographic Surgery (MMS) is a standard treatment for adult skin cancer due to its low recurrence rates and tissue preservation. However, it is less commonly used to treat melanoma in children because the required infrastructure is not widely accessible and many pediatric surgeons are not familiar with MMS.4 With more limited treatment options for pediatric melanoma, it is important to question the role of socioeconomic factors that may contribute to MMS treatment of pediatric patients with melanoma.2

Purpose: The purpose of the study is to investigate pediatric patients with melanoma and assess their tumor characteristics by comparing various skin cancer treatments (Mohs, other treatments [local excision], or no treatment).Methods: This is a retrospective cohort study of pediatric patients (age &lt; 21 years) diagnosed with cutaneous Melanoma who received MMS between 2004 and 2020 in the National Cancer Database (NCDB). Descriptive statistics were collected on the following variables: the year of diagnosis, sex, race, tumor stage, tumor behavior, primary site, and surgical procedure. Overall survival was determined via the Kaplan-Meier test.

Results: 104 cases of pediatric melanoma treated with MMS were identified. Per statistical analysis, it does not appear that surgical frequency has varied yearly from 2004 to 2020 (r² = 0). The median age of patients analyzed was 18 years old. Most patients were female (64.4%, N = 67), White (100%, N=104), non-Hispanic (100%, N=104), and had private insurance (87.3%, N = 90). 70.2% (N=73) of cases were defined as early-stage (stage 0 or I). 72.1% (N=75) of cases were identified as invasive. 45.2% (N=47) of MMS were performed with a margin of 1 cm or less, 19.2% (N=20) were performed with a margin of 1 cm or more, and the remaining had unspecified margins. The most common primary site for MMS was skin of the trunk (33.7%, N=35), followed by the upper limb and shoulder (16.3%, N=17), and the lower limb and hip (15.4%, N=16). All patients were alive at the last contact, with a median overall survival of 182 months (15.2 years).

Discussion: MMS is used commonly in adults to treat a variety of skin tumors that can have aggressive traits such as melanoma. Although it offers low recurrence rates and tissue-sparing treatment in adult populations, MMS frequency has not changed within the pediatric population. MMS is mainly seen in privately insured, White patients with an early stage of melanoma; this is likely due to lower rates and delayed diagnosis in patients with darker skin that would otherwise present with metastatic disease. Given its clinical advantages and low rate of use, further research should address barriers that affect the availability of MMS in the pediatric population.

Citation Format: Zachary G. Brandt, Xinxin Wu, Jared Kennard, Julia Griffin, Peter Silberstein. Mohs surgery trends in 104 cases of pediatric melanoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3566.