Melanomas in children and adolescents: Clinicopathologic features and survival outcomes

[Diagnosis of pediatric melanocytic tumors]

The histological diagnosis of pediatric melanocytic tumors is challenging, as benign nevi often resemble aggressive tumors. Accurate diagnosis is crucial for the early detection of rare pediatric melanomas. Recent advancements have established a classification based on genetic backgrounds. This classification distinguishes between rarer subtypes and includes groups such as conventional melanomas, Spitz tumors, and melanomas arising from congenital melanocytic nevi. While the most common group, Spitz tumors, generally has a favorable prognosis, conventional melanomas and especially those arising from congenital nevi may exhibit an aggressive course similar to that of adult melanoma.

Pediatric melanoma incidence and survival: a fifteen-year nationwide retrospective cohort study in Korea

The aim of this study was to explore the epidemiology of cutaneous malignant melanoma (CMM) and the associated risk factors influencing its occurrence and survival among Koreans aged <20 years. In this retrospective cohort investigation, we identified cases of incident melanoma diagnosed in Korean patients aged 0-19 years between 2004 and 2019, utilizing the National Health Insurance database. We assessed annual fluctuations in age-adjusted incidence rates and examined 5-year survival rates based on various factors, including sex, age, income level, sun-exposed sites, and the Charlson Comorbidity Index. Of 1160 patients, 51.4% were male and 48.6% were female. The mean age of the patients was 11 years, mostly belonging to the top 25% high-income group. The head and neck regions were the most frequently affected sites. The overall age-adjusted incidence rate of melanoma was 0.22 per 100,000 persons. This rate witnessed a decline of 4.5% annually from 2004 to 2012, followed by a subsequent increase of 12.6% annually from 2012 to 2019. Notably, patients with CMM in low-sun-exposed sites exhibited poorer survival rates compared with those in high-sun-exposed areas ( P  < 0.05). The incidence of melanomas in children and adolescents in Korea has shown a rising trend since 2012. Further research is needed to investigate the etiology and risk factors in pediatric patients.

Efficacy of anti PD-1 therapy in children and adolescent melanoma patients (MELCAYA study)

BACKGROUND

Data on the efficacy and safety of anti PD-1 antibodies in children and adolescents (CA) with melanoma are lacking. The aim of this study was to determine outcomes of CA melanoma patients receiving anti PD-1 antibodies.

METHODS

Melanoma patients ≤18 years treated with anti PD-1 were retrospectively retrieved from 15 academic centers. Information on histopathological diagnosis, surgical treatment, systemic therapy, objective response rate (ORR), safety profile was collected. Progression-free survival (PFS) and overall survival (OS) were assessed by Kaplan-Meier method.

RESULTS

Between April 2016 and March 2024, 99 patients treated with systemic therapy were retrieved, 81 treated with anti PD-1 therapy. Median age was 14 years (range 2-18 years), 37 pts were ≤12 yrs. Overall, 38 CA patients received anti PD-1 in adjuvant setting, and the 3-year PFS and OS were 70.6 % and 81.1 %, respectively. Two patients received anti-PD-1 based neoadjuvant treatment, both had a pathologic complete response and remain disease free. Fifty-six received a systemic therapy for advanced disease and among them, 43 received anti PD-1-based therapy for advanced disease in 1st line, while 12 and 5 pts received a 2nd and 3rd line, respectively. Among patients receiving a 1st line therapy with anti PD-1 monotherapy the ORR was 25 %, and the 3-year OS was 34 %. Toxicities were consistent with previous studies in adult melanoma patients.

CONCLUSIONS

Our study provides the first evidence of efficacy of anti PD-1 in CA melanoma patients and supports the use of anti PD-1 therapy in pts ≤18 years, included those <12 years.

Preclinical ImmunoPET Imaging Using a Zr-89-Labeled Anti-CD146 Monoclonal Antibody for Diagnosis of Melanoma

The aim of this study was to evaluate the preclinical efficacy of [89Zr]Zr-DFO-Ab253 as a novel positron emission tomography (PET) tracer for CD146-positive malignant melanoma imaging. Considering the high expression of CD146 in malignant melanoma, this study investigated the effect of different CD146 expression levels on the tumor uptake of [89Zr]Zr-DFO-Ab253. CD146 selectivity was investigated by using the CD146-positive human melanoma cell A375 and the CD146-negative human alveolar epithelial cell A549. The cell uptake of [89Zr]Zr-DFO-Ab253 tracers was investigated, and receptor-binding affinities were measured by radioactive enzyme-linked immunosorbent assay. Biodistribution studies and micro-PET imaging of the radiotracers were performed on mice bearing A375 and A549 xenografts under baseline and blocking conditions. An immunohistochemical test was performed using A375 and A549 tissue sections for CD146 expression level analysis. [89Zr]Zr-DFO-Ab253 was obtained with a high radiochemical yield (87.86 ± 4.66%) and a satisfactory radiochemical purity (>98.0%). The specificity and affinity of [89Zr]Zr-DFO-Ab253 were confirmed in melanoma A375 cells and in vivo PET imaging of A375 tumor models. [89Zr]Zr-DFO-IgG and A549 lung tumors were prepared as control radiotracers and negative models to verify the specificity of [89Zr]Zr-DFO-Ab253 on CD146. [89Zr]Zr-DFO-Ab253 has a Kd of 4.01 ± 0.50 nM. PET imaging and biodistribution showed a higher uptake of [89Zr]Zr-DFO-Ab253 in A375 melanomas than that in A549 tumors (42.1 ± 4.04% vs 7.87 ± 1.30% ID/g at 120 h, P < 0.05). A low tumor uptake of [89Zr]Zr-DFO-IgG was observed with uptakes of 1.91 ± 0.41 and 2.80 ± 0.14 ID%/g when blocked at 120 h. The radiation-absorbed dose was calculated to be 0.13 mSv/MBq. This study demonstrates the synthesis and preclinical evaluation of [89Zr]Zr-DFO-Ab253 and indicates that the novel tracer has promising applications in malignant melanoma-specific PET imaging because of its high uptake and long-time retention in malignant melanoma. It also provides feasibility for the development of integrated molecular probes for diagnosis and treatment based on the CD146 target.

Adjuvant immune checkpoint inhibitor therapy may benefit pediatric patients with stage III melanoma and sentinel lymph node positivity: a case series

Melanoma is the most common skin cancer in children. While the current literature establishes treatment protocols for adult-type melanoma, very few pediatric-specific studies exist, and children are often excluded from melanoma clinical trials2. We report a case series of 23 pediatric patients aged 2-20 years old diagnosed with melanoma at the University of Rochester Medical Center between 1/1/2011 and 1/1/2022. 9/23 patients were Stage III; all patients underwent wide local excision and 9 received adjuvant therapies. 2/23 (8.7%) patients had recurrence of their malignancy after therapy while 21/23 (91.3%) remained without disease progression; 1 patient died from unknown cause, but the rest are alive and currently without disease. All patients whose initial therapy included nivolumab in addition to wide local excision did not have recurrence or progression of their disease. This case series highlights trends in the presentation, treatment, and outcomes of pediatric melanoma; however, additional multi-center studies are needed to establish the clinical utility of such features in pediatric melanoma.

A rare case of palmar congenital nevus with sclerodermoid reaction

Palmar congenital nevus with sclerodermoid reaction has not been reported. It has the potential of deep extension following the fibrous bundle. The utilization of slow Mohs or frozen sections with immunohistochemistry staining was recommended.

Gender differences in pediatric and adolescent melanoma: A retrospective analysis of 4645 cases

BACKGROUND

There is paucity of data on how gender impacts melanoma prognosis in pediatric and adolescent patients.

OBJECTIVES

This study explores gender differences in presentation and survival among pediatric and adolescent patients with melanoma.

METHODS

The National Cancer Database 2004-2018 was queried for cases of primary invasive cutaneous melanoma in pediatric and adolescent patients (birth to 21 years) for a retrospective cohort study.

RESULTS

Of the 4645 cases, 63.4% were female. Median Breslow depth was 1.05 mm for males (interquartile range 0.50-2.31) and 0.80 mm for females (interquartile range 0.40-1.67; P < .001). Trunk was the most common primary site for females (34.3%) and males (32.9%). More females than males were diagnosed with stage I disease (67.8% vs 53.6%). Males had higher rates of regional lymph node positivity (27.9% vs 18.1%; P < .001) and ulceration (17.1% vs 11.4%; P < .001). Five-year overall survival was 95.9% for females and 92.0% for males (P < .001). After adjusting for confounders, male gender independently increased mortality risk (reference: females; adjusted hazard ratio 1.57; 95% confidence interval 1.32-1.86).

LIMITATIONS

Retrospective study.

CONCLUSION

Males exhibited more aggressive pathologic features including greater Breslow thickness and higher ulceration and lymph node positivity rates. Male gender independently increased mortality risk.