BOB Ped Surg 2023 - Steven Scoville, IPSO - Presentation

I'd like to thank you for this opportunity to present our work entitled Comparison of outcomes between surveillance ultrasound and completion lymph node dissection in children and adolescents with sentinel lymph node positive cutaneous melanoma. We have no disclosures. Pediatric melanoma has approximately 500 new cases diagnosed annually in children less than or equal to 18 years old. Compared to adults, we know that childhood melanoma is associated with delayed diagnosis and therefore not surprisingly more frequently has nodal involvement. It also has unique disease mechanisms. Despite these differences though, management of pediatric melanoma is based on adult studies. Melanoma management is largely based on depth of the tumor as well as presence of metastatic disease. Those with disease less than 8 millimeters thick are largely managed with wide local excision, while those with metastatic disease typically involve consideration of surgical excision and or systemic therapy. Those in the middle category of having tumors greater than or equal to 8 millimeters or less than 8 millimeters with high risk features without the presence of metastatic involvement, typically undergo wide local excision with sentinel lymph node biopsies. If the sentinel lymph node biopsy is positive, then these patients would typically undergo ultrasound observation versus a completion lymph node dissection, which has a high risk of morbidity. Within the past six years, two adult trials known as a DECOG-SLT and the MSLT-2 trials helped to show that within these low to intermediate risk patients, there's no significant difference in outcomes for patients with positive sentinel lymph node biopsies who were followed with ultrasound observation versus completion lymph node dissections. However, there is no pediatric data to support one versus the other. Therefore, we set out to answer this question. Our study included patients less than or equal to 18 years old, diagnosed with cutaneous melanoma between 2010 and 2020. 14 total institutions participated through the Pediatric Surgical Oncology Research Collaborative, otherwise known as PSOC. Of the 252 patients included in this study, we found nearly equal distribution of age, tumor location, while race was predominantly white consistent with prior literature. Bresla depth ranged from 2 mm C2 to 20 mm in depth with a median of 2.55 mm and extent of disease was nearly split between localized and regionalized disease. In categorizing our patients, we had four patients who underwent wide local excision alone that went on to undergo ultrasound observation. We then had a total of 227 patients who underwent wide local excision with sentinel lymph node biopsies. 111 of these had negative sentinel lymph nodes with six of those who went on to undergo ultrasound observation. In contrast, 115 patients had positive sentinel lymph node biopsies about 51%. Of those, 36 went on to have ultrasound observations, whereas 65 underwent completion lymph node dissections. Finally, two patients had wide local excision alone or had unknown sentinel lymph node biopsy results went on to have completion lymph node dissections. For a total of 46 patients in the ultrasound observation group compared to 67 that had completion lymph node dissections. Comparing outcomes between ultrasound observation versus completion lymph node dissection, we found that patients who underwent completion lymph node dissection were significantly older and more likely to receive adjuvin therapy. Furthermore, there was no significant differences between recurrence or death from disease between these two groups. Additional subgroup analysis found that positive sentinel lymph node biopsies had significantly higher rate of disease recurrence at 18% compared to 3% for the negative sentinel lymph node biopsy group. We also found that only 21% of those who underwent completion lymph node dissection had additional positive nodal disease. However, we found that rate of recurrence was not significantly different between completion lymph node dissection patients with or without additional nodal burden. In doing an analysis based on recurrence versus no recurrence, we found that recurrence was associated with positive nodal disease, deeper Bresla depth and greater use of advent therapy and a higher rate of death. Therefore, to summarize, pediatric melanoma presents as advanced disease with nearly 50% positive sentinel lymph node biopsy rate. Management of nodal disease had no significant impact on disease outcomes with respect to recurrence or death from disease. Only 21% of patients that underwent completion lymph node dissection had additional nodes discovered, and findings of additional nodal disease did not significantly correlate with recurrence. Recurrence did more strongly associate with positive sentinel lymph node biopsies and deeper Bresla depth. I would like to personally thank our many collabora- collaborators across the 14 institutions who helped with our data acquisition, analysis, and our manuscript preparation. Thank you.