BACKGROUND: Despite advances in therapy, nearly 30% of children with rhabdomyosarcoma experience progressive or relapsed disease, which is often fatal. PATIENTS AND METHODS: To facilitate the development of a retrieval therapy protocol, we studied potential risk factors that were predictive of survival after first relapse in 605 children who were enrolled onto three consecutive Intergroup Rhabdomyosarcoma Study Group protocols. RESULTS: The median survival time from first recurrence was 0.8 years; the estimated percentage of patients who survived 5 years from first recurrence was 17% ± 2% (mean ± SD). Univariate analysis showed that tumor histology was an important predictor of 5-year survival (P < .001): the 5-year survival rate was 64% for patients with botryoid tumors (n = 19), 26% for patients with embryonal tumors (n = 313), and 5% for patients with alveolar or undifferentiated sarcoma (n = 273). Further analysis identified prognostic factors within histologic subtypes (P < .001). For patients with embryonal tumors, the estimated 5-year survival rate was 52% for patients who initially presented with stage 1 or group I disease, 20% for those with stage 2/3 or group II/III disease, and 12% for those with group IV disease. For patients with stage 1/group I disease, estimated 5-year survival rates were higher for patients with local (72%) or regional (50%) recurrence than for those with distant (30%) recurrence. Among patients with alveolar or undifferentiated sarcoma, only the disease group predicted outcome: the 5-year survival estimate was 40% for group I versus 3% for groups II through IV. We identified a “favorable risk” group (approximately 20% of patients) whose 5-year estimated survival rate was near 50%; for all other patients, the estimated survival was near 10%. CONCLUSION: This analysis demonstrates that the probability of 5-year survival after relapse for rhabdomyosarcoma is dependent on several factors at the time of initial diagnosis, including histologic subtype, disease group, and stage. These findings will form the basis of a multi-institutional risk-adapted relapse protocol for childhood rhabdomyosarcoma.

Despite remarkable advances in the genomic characterization of adult melanoma, the molecular pathogenesis of pediatric melanoma remains largely unknown. We analyzed 15 conventional melanomas (CMs), 3 melanomas arising in congenital nevi (CNMs), and 5 spitzoid melanomas (SMs), using various platforms, including whole genome or exome sequencing, the molecular inversion probe assay, and/or targeted sequencing. CMs demonstrated a high burden of somatic single-nucleotide variations (SNVs), with each case containing a TERT promoter (TERT-p) mutation, 13/15 containing an activating BRAF V600 mutation, and >80% of the identified SNVs consistent with UV damage. In contrast, the three CNMs contained an activating NRAS Q61 mutation and no TERT-p mutations. SMs were characterized by chromosomal rearrangements resulting in activated kinase signaling in 40%, and an absence of TERT-p mutations, except for the one SM that succumbed to hematogenous metastasis. We conclude that pediatric CM has a very similar UV-induced mutational spectrum to that found in the adult counterpart, emphasizing the need to promote sun protection practices in early life and to improve access to therapeutic agents being explored in adults in young patients. In contrast, the pathogenesis of CNM appears to be distinct. TERT-p mutations may identify the rare subset of spitzoid melanocytic lesions prone to disseminate.

BACKGROUND: Insulin‐like growth factor‐1 receptor (IGF‐1R) is implicated in the pathogenesis of rhabdomyosarcoma (RMS), osteosarcoma (OS), and synovial sarcoma (SS). The authors conducted a multi‐institutional phase 2 trial of the monoclonal antibody R1507 in patients with various subtypes of recurrent or refractory sarcomas.METHODS: Eligibility criteria included age ≥2 years and a diagnosis of recurrent or refractory RMS, OS, SS, and other soft tissue sarcomas. Patients received a weekly dose of 9 mg/kg R1507 intravenously. The primary endpoint was the best objective response rate using World Health Organization criteria. Tumor imaging was performed every 6 weeks × 4 and every 12 weeks thereafter.RESULTS: From December 2007 through August 2009, 163 eligible patients from 33 institutions were enrolled. The median patient age was 31 years (range, 7‐85 years). Histologic diagnoses included OS (n = 38), RMS (n = 36), SS (n = 23), and other sarcomas (n = 66). The overall objective response rate was 2.5% (95% confidence interval, 0.7%‐6.2%). Partial responses were observed in 4 patients, including 2 patients with OS, 1 patient with RMS, and 1 patient with alveolar soft part sarcoma. Four additional patients (3 with RMS and 1 with myxoid liposarcoma) had a ≥50% decrease in tumor size that lasted for <4 weeks. The median progression‐free survival was 5.7 weeks, and the median overall survival was 11 months. The most common grade 3/4 toxicities were metabolic (12%), hematologic (6%), gastrointestinal (4%), and general constitutional symptoms (8%).CONCLUSIONS: R1507 is safe and well tolerated but has limited activity in patients with recurrent or refractory bone and soft tissue sarcomas. Additional studies to help identify the predictive factors associated with clinical benefit in selected histologies such as RMS appear to be warranted. Cancer 2014;120:2448–2456. © 2014 American Cancer Society.

PURPOSE: We evaluated whether combining a humanized antidisialoganglioside monoclonal antibody (hu14.18K322A) throughout therapy improves early response and outcomes in children with newly diagnosed high-risk neuroblastoma.PATIENTS AND METHODS: We conducted a prospective, single-arm, three-stage, phase II clinical trial. Six cycles of induction chemotherapy were coadministered with hu14.18K322A, granulocyte-macrophage colony-stimulating factor (GM-CSF), and low-dose interleukin-2 (IL-2). The consolidation regimen included busulfan and melphalan. When available, an additional cycle of parent-derived natural killer cells with hu14.18K322A was administered during consolidation (n = 31). Radiation therapy was administered at the end of consolidation. Postconsolidation treatment included hu14.18K322A, GM-CSF, IL-2, and isotretinoin. Early response was assessed after the first two cycles of induction therapy. End-of-induction response, event-free survival (EFS), and overall survival (OS) were evaluated.RESULTS: Sixty-four patients received hu14.18K322A with induction chemotherapy. This regimen was well tolerated, with continuous infusion narcotics. Partial responses (PRs) or better after the first two chemoimmunotherapy cycles occurred in 42 of 63 evaluable patients (66.7%; 95% CI, 55.0 to 78.3). Primary tumor volume decreased by a median of 75% (range, 100% [complete disappearance]-5% growth). Median peak hu14.18K322A serum levels in cycle one correlated with early response to therapy ( P = .0154, one-sided t-test). Sixty of 62 patients (97%) had an end-of-induction partial response or better. No patients experienced progressive disease during induction. The 3-year EFS was 73.7% (95% CI, 60.0 to 83.4), and the OS was 86.0% (95% CI, 73.8 to 92.8), respectively.CONCLUSION: Adding hu14.18K322A to induction chemotherapy improved early objective responses, significantly reduced tumor volumes in most patients, improved end-of-induction response rates, and yielded an encouraging 3-year EFS. These results, if validated in a larger study, may be practice changing.

PURPOSE: Adrenocortical carcinoma (ACC) is a rare aggressive pediatric malignancy with distinct biology. Its treatment follows the principles developed for adults; pediatric-specific studies are scarce. PATIENTS AND METHODS: Prospective single-arm risk-stratified interventional study. Study objectives were (1) to describe the outcome of patients with stage I ACC treated with adrenalectomy alone; (2) to describe the outcome of stage II patients (completely resected > 200 cc or > 100 g) treated with adrenalectomy and retroperitoneal lymph node dissection; and (3) to describe the outcome of patients with stage III or IV treated with mitotane and chemotherapy. RESULTS: Between September 2006 and May 2013, 78 patients (77 eligible, 51 females) were enrolled. The 5-year event-free survival estimates for stages I (24 patients), II (15 patients), III (24 patients), and IV (14 patients) were 86.2%, 53.3%, 81%, and 7.1%, respectively. The corresponding 5-year overall survival estimates were 95.2%, 78.8%, 94.7%, and 15.6%, respectively. On univariate analysis, age, stage, presence of virilization, Cushing syndrome, or hypertension, germline TP53 status, and presence of a somatic ATRX mutation were associated with outcome. On multivariable analysis, only stage and age were significantly associated with outcome. The probabilities of mitotane and chemotherapy feasibility events were 10.5% and 31.6%, respectively. CONCLUSION: Outcome for children with stage I ACC is excellent with surgery. Outcome for patients with stage II disease is inferior despite retroperitoneal lymph node dissection. Patients with stage III ACC have an excellent outcome combining surgery and chemotherapy. Patients with stage IV ACC are older and have a poor outcome; new treatments should be explored for this high-risk group. The combination of mitotane and chemotherapy as prescribed in ARAR0332 resulted in significant toxicity; one third of patients with advanced disease could not complete the scheduled treatment.