UV-radiation and MC1R germline mutations are risk factors for the development of conventional and spitzoid melanomas in children and adolescents.

BACKGROUND: Genomic characterisation has led to an improved understanding of adult melanoma. However, the aetiology of melanoma in children is still unclear and identifying the correct diagnosis and therapeutic strategies remains challenging. METHODS: Exome sequencing of matched tumour-normal pairs from 26 paediatric patients was performed to study the mutational spectrum of melanomas. The cohort was grouped into different categories: spitzoid melanoma (SM), conventional melanoma (CM), and other melanomas (OT). FINDINGS: In all patients with CM (n = 10) germline variants associated with melanoma were found in low to moderate melanoma risk genes: in 8 patients MC1R variants, in 2 patients variants in MITF, PTEN and BRCA2. Somatic BRAF mutations were detected in 60% of CMs, homozygous deletions of CDKN2A in 20%, TERTp mutations in 30%. In the SM group (n = 12), 5 patients carried at least one MC1R variant; somatic BRAF mutations were detected in 8.3%, fusions in 25% of the cases. No SM showed a homozygous CDKN2A deletion nor a TERTp mutation. In 81.8% of the CM/SM cases the UV damage signatures SBS7 and/or DBS1 were detected. The patient with melanoma arising in giant congenital nevus (CNM) demonstrated the characteristic NRAS Q61K mutation. INTERPRETATION: UV-radiation and MC1R germline variants are risk factors in the development of conventional and spitzoid paediatric melanomas. Paediatric CMs share genomic similarities with adult CMs while the SMs differ genetically from the CM group. Consistent genetic characterization of all paediatric melanomas will potentially lead to better subtype differentiation, treatment, and prevention in the future. FUNDING: Found in Acknowledgement.

Therapy and prognostic significance of regional lymph node involvement in embryonal rhabdomyosarcoma: a report from the European paediatric Soft tissue sarcoma Study Group.

PURPOSE: Regional lymph node disease (N1) is a component of the risk-based treatment stratification in rhabdomyosarcoma (RMS). The purpose of this study was to determine the contribution of nodal disease to the prognosis of patients with non-metastatic embryonal RMS (ERMS) and analyse their outcome by treatment received. PATIENTS AND METHODS: Between 2005 and 2016, 1294 children with ERMS were enrolled in the European paediatric Soft tissue sarcoma Study Group (EpSSG) RMS 2005 protocol, 143 patients with N1. Treatment comprised 9 cycles of ifosfamide, vincristine and dactinomycin. Some patients also received doxorubicin and/or maintenance if enrolled in the randomised studies. Local treatment was planned after 4 cycles of chemotherapy and included surgery to remove macroscopic residual tumour and/or radiotherapy (primary tumour and involved nodes). RESULTS: N1 patients were older and presented with tumours of unfavourable size, invasiveness, site and resectability. Unlike alveolar RMS, nodal involvement was more frequent in the head and neck area and rare in extremity sites. The 5-year event-free and overall survival were 75.5% and 86.3% for patients with N0, and 65.2% and 70.7% for patients with N1, respectively. The nodal involvement and the result of surgery at diagnosis (Intergroup Rhabdomyosarcoma Study group) were independent prognostic factors on multivariate analysis. Considering only patients with N1 ERMS, we were not able to identify any treatment variables which correlated with the outcome. CONCLUSION: In the case of nodal involvement, patients with ERMS present different characteristics and a better outcome than alveolar RMS. Regional nodal involvement is an independent prognostic factor in ERMS, therefore it is appropriate to include this population in the high-risk category.

Brachytherapy for Pediatric Patients at Gustave Roussy Cancer Campus: A Model of International Cooperation for Highly Specialized Treatments.

PURPOSE: Childhood cancer is rare, and treatment is frequently associated with long-term morbidity. Disparities in survival and long-term side effects encourage the establishment of networks to increase access to complex organ-conservative strategies, such as brachytherapy. We report our experience of an international cooperation model in childhood cancers. METHODS AND MATERIALS: We examined the outcome of all children referred to our center from national or international networks to be treated according to a multimodal organ-conservative approach, including brachytherapy. RESULTS: We identified 305 patients whose median age at diagnosis was 2.2 years (range, 1.4 months to 17.2 years). Among these patients, 99 (32.4%) were treated between 2015 and 2020; 172 (56.4%) were referred from national centers; and 133 (43.6%) were international patients from 31 countries (mainly Europe). Also, 263 patients were referred for primary treatment and 42 patients were referred for salvage treatment. Genitourinary tumors were the most frequent sites, with 56.4% bladder/prostate rhabdomyosarcoma and 28.5% gynecologic tumors. In addition to brachytherapy, local treatment consisted of partial tumor resection in 207 patients (67.9%), and 39 patients (13%) had additional external radiation therapy. Median follow-up was 58 months (range, 1 month to 48 years), 93 months for national patients, and 37 months for international patients (P < .0001). Five-year local control, disease-free survival, and overall survival rates were 90.8% (95% confidence interval [CI], 87.3%-94.4%), 84.4% (95% CI, 80.1%-89.0%), and 93.3% (95% CI, 90.1%-96.5%), respectively. Patients referred for salvage treatment had poorer disease-free survival (P < .01). Implementation of image guided pulse-dose-rate brachytherapy was associated with better local control among patients with rhabdomyosarcoma referred for primary treatment (hazard ratio, 9.72; 95% CI, 1.24-71.0). At last follow-up, 16.7% patients had long-term severe treatment-related complications, and 2 patients (0.7%) had developed second malignancy. CONCLUSIONS: This retrospective series shows the feasibility of a multinational referral network for brachytherapy allowing high patient numbers in rare pediatric cancers. High local control probability and acceptable late severe complication probability could be achieved despite very challenging situations. This cooperation model could serve as a basis for generating international reference networks for high-tech radiation such as brachytherapy to increase treatment care opportunities and cure probability.

Localised rhabdomyosarcoma in infants (<12 months) and young children (12-36 months of age) treated on the EpSSG RMS 2005 study.

BACKGROUND: Infants (<12 months) with rhabdomyosarcoma have historically had poorer outcome than the older age groups. We present outcomes for infants and young children aged 12-36 months with localised rhabdomyosarcoma with a particular emphasis on infants. PATIENTS AND METHODS: All children less than 36 months of age enrolled on the EpSSG RMS 2005 study for localised disease are included. Treatment comprised chemotherapy, local surgery and/or radiation therapy adapted to risk group and age. Main outcome measures were event free survival (EFS) and overall survival (OS). RESULTS: Outcome data were available for 485/490 patients aged less than 36 months, 110 were infants. Infants received chemotherapy according to the risk group with no toxic deaths. Radiotherapy was delivered to 33.6% of infants and 63.5% of 12-36 months old, with respectively 41.7% and 22.2% receiving brachytherapy. Radical surgery was performed in 62% of infants and 57.1% of 12-36 months old. Median follow up for patients who are alive (n = 393) was 72.7 months (range 6.9-158.2). Five-year OS for infants was 88.4% (95%CI 80.3-93.2), which is significantly better than the OS in 12-36 months old patients of 78.0% (95%CI 73.2-82.0; p = 0.0204). Five-year EFS for infants was 72.5% (95%CI 62.8-80.0) compared with 66.1% (95%CI 61.0-70.7; p = 0.2663) for 12-36 months old. CONCLUSION: Infants treated on RMS 2005 achieved excellent EFS and OS. The EpSSG RMS 2005 chemotherapy regimen, combined with an increase in the application of adequate local therapy, improvements in imaging and supportive care and potentially favourable patients' characteristics may have contributed to these results.

Randomized Trial of Two Induction Therapy Regimens for High-Risk Neuroblastoma: HR-NBL1.5 International Society of Pediatric Oncology European Neuroblastoma Group Study.

PURPOSE: Induction therapy is a critical component of the therapy of high-risk neuroblastoma. We aimed to assess if the Memorial Sloan Kettering Cancer Center (MSKCC) N5 induction regimen (MSKCC-N5) would improve metastatic complete response (mCR) rate and 3-year event-free survival (EFS) compared with rapid COJEC (rCOJEC; cisplatin [C], vincristine [O], carboplatin [J], etoposide [E], and cyclophosphamide [C]). PATIENTS AND METHODS: Patients (age 1-20 years) with stage 4 neuroblastoma or stage 4/4s aged < 1 year with MYCN amplification were eligible for random assignment to rCOJEC or MSKCC-N5. Random assignment was stratified according to national group and metastatic sites. Following induction, therapy comprised primary tumor resection, high-dose busulfan and melphalan, radiotherapy to the primary tumor site, and isotretinoin with ch14.18/CHO (dinutuximab beta) antibody with or without interleukin-2 immunotherapy. The primary end points were mCR rate and 3-year EFS. RESULTS: A total of six hundred thirty patients were randomly assigned to receive rCOJEC (n = 313) or MSKCC-N5 (n = 317). Median age at diagnosis was 3.2 years (range, 1 month to 20 years), and 16 were younger than 1 year of age with MYCN amplification. mCR rate following rCOJEC induction (32%, 86/272 evaluable patients) was not significantly different from 35% (99/281) with MSKCC-N5 (P = .368), and 3-year EFS was 44% ± 3% for rCOJEC compared with 47% ± 3% for MSKCC-N5 (P = .527). Three-year overall survival was 60% ± 3% for rCOJEC compared with 65% ± 3% for MSKCC-N5 (P = .379). Toxic death rates with both regimens were 1%. However, nonhematologic CTC grade 3 and 4 toxicities were higher with MSKCC-N5: 68% (193/283) versus 48% (129/268) (P < .001); infection 35% versus 25% (P = .011); stomatitis 25% versus 3% (P < .001); nausea and vomiting 17% versus 7% (P < .001); and diarrhea 7% versus 3% (P = .011). CONCLUSION: No difference in outcome was observed between rCOJEC and MSKCC-N5; however, acute toxicity was less with rCOJEC, and therefore rCOJEC is the preferred induction regimen for International Society of Pediatric Oncology European Neuroblastoma Group.

Cutaneous melanoma in children and adolescents: The EXPeRT/PARTNER diagnostic and therapeutic recommendations.

Cutaneous melanoma is rare in children and, like other very rare pediatric tumors, it suffers from a shortage of knowledge and clinical expertise. The clinical management of pediatric melanoma is often challenging. Its clinical and pathological diagnosis may be difficult, and there is no standard treatment. In the absence of specific treatment guidelines, young patients are generally treated following the same principle as for adults, but concern remains about their access to clinical trials and new drugs, which have been shown to dramatically change the natural history of advanced melanoma. This paper presents the internationally recognized recommendations for the diagnosis and treatment of children and adolescents with cutaneous melanoma, established by the European Cooperative Study Group for Pediatric Rare Tumors (EXPeRT) within the EU-funded project called PARTNER (Paediatric Rare Tumours Network - European Registry). Main recommendations for melanoma are to discuss pediatric patients in multidisciplinary teams that include both pediatric oncologists and specialists in adult melanoma; to enroll patients in prospective trials, if available; to collect data in national-international databases; and to develop an effective international collaboration between pediatric and adult melanoma groups in order to facilitate the transfer of potentially effective new agents from the adult to the pediatric setting.

Pleuropulmonary blastoma in children and adolescents: The EXPeRT/PARTNER diagnostic and therapeutic recommendations.

Pleuropulmonary blastoma (PPB) is a rare cancer occurring mainly during early childhood and often associated with germline DICER1 mutations. It is classified by the macroscopic appearance into three interrelated clinico-pathologic entities on a developmental continuum. Complete tumor resection is a main prognostic factor and can be performed at diagnosis or after neoadjuvant treatment that includes chemotherapy and in some cases radiotherapy. Optimal modalities of neo- or adjuvant treatments can be challenging taking into account potential long-term toxicities in this young population. This paper presents the recommendations for diagnosis and treatment of children and adolescents with PPB elaborated by the European Cooperative Study Group for Pediatric Rare Tumors (EXPeRT) within the European Union-funded project PARTNER (Paediatric Rare Tumours Network - European Registry).

Cardiac resynchronization therapy for the failing Fontan patient.

Myocardial dysfunction is the leading cause of death in single-ventricle patients. Heart transplantation has traditionally been reserved for Fontan patients with end-stage myocardial dysfunction. Cardiac resynchronization therapy with multisite pacing was found to improve the myocardial performance in Fontan patients in acute postoperative settings; however, its role is unclear in chronic Fontan patients with progressive myocardial dysfunction. We present a case in which cardiac resynchronization therapy improved both hemodynamics and clinical condition in a Fontan patient with advanced myocardial dysfunction.