Reappraisal of prognostic factors used in the European Pediatric Soft Tissue Sarcoma Study Group RMS 2005 study for localized rhabdomyosarcoma to optimize risk stratification and generate a prognostic nomogram.

BACKGROUND: The objective of this study was to investigate the role of clinical factors together with FOXO1 fusion status in patients with nonmetastatic rhabdomyosarcoma (RMS) to develop a predictive model for event-free survival and provide a rationale for risk stratification in future trials. METHODS: The authors used data from patients enrolled in the European Pediatric Soft Tissue Sarcoma Study Group (EpSSG) RMS 2005 study (EpSSG RMS 2005; EudraCT number 2005-000217-35). The following baseline variables were considered for the multivariable model: age at diagnosis, sex, histology, primary tumor site, Intergroup Rhabdomyosarcoma Studies group, tumor size, nodal status, and FOXO1 fusion status. Main effects and significant second-order interactions of candidate predictors were included in a multiple Cox proportional hazards regression model. A nomogram was generated for predicting 5-year event-free survival (EFS) probabilities. RESULTS: The EFS and overall survival rates at 5 years were 70.9% (95% confidence interval, 68.6%-73.1%) and 81.0% (95% confidence interval, 78.9%-82.8%), respectively. The multivariable model retained five prognostic factors, including age at diagnosis interacting with tumor size, tumor primary site, Intergroup Rhabdomyosarcoma Studies clinical group, and FOXO1 fusion status. Based on each patient's total score in the nomogram, patients were stratified into four groups. The 5-year EFS rates were 94.1%, 78.4%, 65.2%, and 52.1% in the low-risk, intermediate-risk, high-risk, and very-high-risk groups, respectively, and the corresponding 5-year overall survival rates were 97.2%, 91.5%, 74.3%, and 60.8%, respectively. CONCLUSIONS: The results presented here provide the rationale to modify the EpSSG stratification, with the most significant change represented by the replacement of histology with fusion status. This classification was adopted in the new international trial launched by the EpSSG.

Perianal/perineal rhabdomyosarcoma: Results of the SIOP MMT 95, Italian RMS 96, and EpSSG RMS 2005 studies.

BACKGROUND/OBJECTIVES: Rhabdomyosarcoma of the perianal/perineal region (PRMS) is rare, with poor survival and limited understanding of the functional consequences of treatment. DESIGN/METHODS: International Society of Pediatric Oncology (SIOP) malignant mesenchymal tumor (MMT) 95, Italian RMS 96, and European paediatric Soft tissue sarcoma Study Group (EpSSG) RMS 2005 studies were interrogated to identify factors that impact survival; in RMS 2005, functional outcomes were analyzed. RESULTS: Fifty patients (nonmetastatic) were identified, median age 6.4 years (range: 0.1-19.6): 29 male, 21 female. Tumors were >5 cm in 33 patients. Histopathological subtype was alveolar in 35. Lymph nodes were involved in 23 patients. In RMS 2005, 16/21 (76%) tested alveolar tumors had positive FOXO1 fusion status. Diagnostic biopsy was performed in 37. Primary resection (13) was complete (R0) in one. Delayed primary excision (16) was complete in three. Radiotherapy (RT) in 34/50 patients included external beam (28), brachytherapy (3), and both (3). Nodal RT was given in 16/23 N1 patients (70%). Median follow-up of alive patients (29) was 84.1 months (range: 3.6-221.1). Relapse or progression occurred in 24 patients (48%), 87% were fatal and most events (63%) were locoregional. Five-year event-free survival (EFS) was 47.8 (95% CI: 32.8-61.3), and 5-year overall survival (OS) was 52.6 (95% CI: 36.7-66.2), with age ≥10 years and tumor size >5 cm impacting 5-year EFS and OS (p < .05). Functional outcome data showed bowel, genito-urinary, and psychological issues; fecal incontinence in four of 21 survivors, and urinary symptoms in two of 21. CONCLUSIONS: About 60% of patients with nonmetastatic PRMS survive; older patients and those with large tumors have the worst outcomes. Biopsy should be the initial procedure, and definitive local therapy individualized. Quality-of-life and functional studies are needed to better understand the consequences of treatment.

Instability of the mitochondrial alanyl-tRNA synthetase underlies fatal infantile-onset cardiomyopathy.

Recessively inherited variants in AARS2 (NM_020745.2) encoding mitochondrial alanyl-tRNA synthetase (mt-AlaRS) were first described in patients presenting with fatal infantile cardiomyopathy and multiple oxidative phosphorylation defects. To date, all described patients with AARS2-related fatal infantile cardiomyopathy are united by either a homozygous or compound heterozygous c.1774C>T (p.Arg592Trp) missense founder mutation that is absent in patients with other AARS2-related phenotypes. We describe the clinical, biochemical and molecular investigations of two unrelated boys presenting with fatal infantile cardiomyopathy, lactic acidosis and respiratory failure. Oxidative histochemistry showed cytochrome c oxidase-deficient fibres in skeletal and cardiac muscle. Biochemical studies showed markedly decreased activities of mitochondrial respiratory chain complexes I and IV with a mild decrease of complex III activity in skeletal and cardiac muscle. Using next-generation sequencing, we identified a c.1738C>T (p.Arg580Trp) AARS2 variant shared by both patients that was in trans with a loss-of-function heterozygous AARS2 variant; a c.1008dupT (p.Asp337*) nonsense variant or an intragenic deletion encompassing AARS2 exons 5-7. Interestingly, our patients did not harbour the p.Arg592Trp AARS2 founder mutation. In silico modelling of the p.Arg580Trp substitution suggested a deleterious impact on protein stability and folding. We confirmed markedly decreased mt-AlaRS protein levels in patient fibroblasts, skeletal and cardiac muscle, although mitochondrial protein synthesis defects were confined to skeletal and cardiac muscle. In vitro data showed that the p.Arg580Trp variant had a minimal effect on activation, aminoacylation or misaminoacylation activities relative to wild-type mt-AlaRS, demonstrating that instability of mt-AlaRS is the biological mechanism underlying the fatal cardiomyopathy phenotype in our patients.

Pathology of childhood rhabdomyosarcoma: A consensus opinion document from the Children's Oncology Group, European Paediatric Soft Tissue Sarcoma Study Group, and the Cooperative Weichteilsarkom Studiengruppe.

The diagnosis and classification of rhabdomyosarcoma (RMS) has undergone several shifts over the last 30 years. While the main diagnostic categories remained the same, changes in the histologic criteria necessary for diagnosis, as well as varied reliance on immunohistochemical and molecular data over time, have created confusion, particularly regarding how these shifts impacted risk stratification and enrollment onto clinical trials. The goal of this report is to review the evolution and current status of RMS diagnosis, focusing on diagnostic criteria in the Children's Oncology Group (COG), the European Paediatric Soft Tissue Sarcoma Group (EpSSG), and the Cooperative Weichteilsarkom Studiengruppe (CWS). In addition, we emphasize research tools used to classify RMS and address biological questions within current clinical trials run by each group. The INternational Soft Tissue SaRcoma ConsorTium (INSTRuCT) initiative will maximize potential to optimize risk stratification by recognizing and accounting for differences in historical data and current practices.

Paratesticular rhabdomyosarcoma-Impact of locoregional approach on patient outcome: A report from the European paediatric Soft tissue sarcoma Study Group (EpSSG).

BACKGROUND: Paratesticular rhabdomyosarcoma (PT RMS) is rare compared to benign scrotal pathology. Inappropriate first surgery (InFS) required supplementary treatment to maintain excellent outcomes. Initial staging of regional lymph nodes is important. The aim of this study was to determine to what extent the quality of locoregional approach impacted on patient morbidity and survival. DESIGN/METHODS: Analysis was performed on all nonmetastatic PT RMS patients enrolled in the European paediatric Soft tissue sarcoma Study Group (EpSSG) RMS 2005 protocol. Aspects assessed were adherence to surgical guidelines and impact of protocol violations, relapse analysis, and survival outcomes. RESULTS: Analysis was performed on 237 patients, with median follow up of 67.1 months. Median age was 9.0 years. InFS occurred in 75 of 237 (32%) patients. InFS required intensified chemotherapy (10) and local therapy. After InFS, 61 required primary reexcision and five delayed surgery. Of 26 recurrences, the risk of relapse was higher in patients ≥10 years (21/26) and was mainly locoregional in 16 of 26 recurrences (± metastatic). Sixteen of 26 died with 14 of 16 patients ≥10 years. Nodal relapse neither occurred when N1 nodes were identified at diagnosis, nor after surgical staging. Five-year overall survival (OS) at age <10 years versus ≥10 years was 98.1 and 86.7%, respectively (P = .0013). Event-free survival (EFS) at age <10 years versus ≥10 years was 95.8 and 79.6%, respectively (P = .0004). OS and EFS did not highlight a significant difference in patients undergoing appropriate versus InFS (P = .8479, P = .2780, respectively). CONCLUSIONS: InFS required intensified therapy to maintain excellent OS and EFS, so better anticipation of malignancy is required. Surgical staging of the retroperitoneal lymph nodes should be performed in patients ≥10 years old.

Dermatofibrosarcoma protuberans in children and adolescents: The European Paediatric Soft Tissue Sarcoma Study Group prospective trial (EpSSG NRSTS 2005).

BACKGROUND: As dermatofibrosarcoma protuberans (DFSP) are rare with no prospective series within paediatric sarcoma trials, the European Paediatric Soft Tissue Sarcoma Study Group (EpSSG) examined the clinical data and outcomes of DFSP enrolled in a multinational study of non-rhabdomyosarcoma soft tissue sarcomas (NRSTS). PATIENTS AND METHODS: Forty-six patients with confirmed DFSP were enrolled into the EpSSG NRSTS 2005 study. All had surgical resection and none had any further therapy at diagnosis. RESULTS: The median age at diagnosis was 6.9 years (range 0.4-17.5). All patients had localised disease, and the majority had small <5 cm tumours (93%), and 76% had Intergroup Rhabdomyosarcoma Study (IRS) I tumours. All patients had up front surgery, 32 requiring two operations. There were 11 patients with IRS II tumours, of which only two went on to have a local recurrence. After a median follow up of 49.0 months (range 4.2-130.9), all patients were alive at the time of this report, with 5-year event-free survival of 92.6% (CI 78.8-97.6) with a 100% overall survival. CONCLUSION: This report demonstrates the ability to run prospective paediatric studies in NRSTS in multiple European countries, with reasonable numbers of DFSP patients, with few events and no deaths, and hence excellent outcomes.

Vinorelbine and continuous low-dose cyclophosphamide as maintenance chemotherapy in patients with high-risk rhabdomyosarcoma (RMS 2005): a multicentre, open-label, randomised, phase 3 trial.

BACKGROUND: For more than three decades, standard treatment for rhabdomyosarcoma in Europe has included 6 months of chemotherapy. The European paediatric Soft tissue sarcoma Study Group (EpSSG) aimed to investigate whether prolonging treatment with maintenance chemotherapy would improve survival in patients with high-risk rhabdomyosarcoma. METHODS: RMS 2005 was a multicentre, open-label, randomised, controlled, phase 3 trial done at 102 hospitals in 14 countries. We included patients aged 6 months to 21 years with rhabdomyosarcoma who were considered to be at high risk of relapse: those with non-metastatic incompletely resected embryonal rhabdomyosarcoma occurring at unfavourable sites with unfavourable age (≥10 years) or tumour size (>5 cm), or both; those with any non-metastatic rhabdomyosarcoma with nodal involvement; and those with non-metastatic alveolar rhabdomyosarcoma but without nodal involvement. Patients in remission after standard treatment (nine cycles of ifosfamide, vincristine, dactinomycin with or without doxorubicin, and surgery or radiotherapy, or both) were randomly assigned (1:1) to stop treatment or continue maintenance chemotherapy (six cycles of intravenous vinorelbine 25 mg/m2 on days 1, 8, and 15, and daily oral cyclophosphamide 25 mg/m2, on days 1-28). Randomisation was done by use of a web-based system and was stratified (block size of four) by enrolling country and risk subgroup. Neither investigators nor patients were masked to treatment allocation. The primary outcome was disease-free survival in the intention-to-treat population. Secondary outcomes were overall survival and toxicity. This trial is registered with EudraCT, number 2005-000217-35, and ClinicalTrials.gov, number NCT00339118, and follow-up is ongoing. FINDINGS: Between April 20, 2006, and Dec 21, 2016, 371 patients were enrolled and randomly assigned to the two groups: 186 to stop treatment and 185 to receive maintenance chemotherapy. Median follow-up was 60·3 months (IQR 32·4-89·4). In the intention-to-treat population, 5-year disease-free survival was 77·6% (95% CI 70·6-83·2) with maintenance chemotherapy versus 69·8% (62·2-76·2) without maintenance chemotherapy (hazard ratio [HR] 0·68 [95% CI 0·45-1·02]; p=0·061), and 5-year overall survival was 86·5% (95% CI 80·2-90·9) with maintenance chemotherapy versus 73·7% (65·8-80·1) without (HR 0·52 [95% CI 0·32-0·86]; p=0·0097). Toxicity was manageable in patients who received maintenance chemotherapy: 136 (75%) of 181 patients had grade 3-4 leucopenia, 148 (82%) had grade 3-4 neutropenia, 19 (10%) had anaemia, two (1%) had thrombocytopenia, and 56 (31%) had an infection. One (1%) patient had a grade 4 non-haematological toxicity (neurotoxicity). Two treatment-related serious adverse events occurred: one case of inappropriate antidiuretic hormone secretion and one of a severe steppage gait with limb pain, both of which resolved. INTERPRETATION: Adding maintenance chemotherapy seems to improve survival for patients with high-risk rhabdomyosarcoma. This approach will be the new standard of care for patients with high-risk rhabdomyosarcoma in future EpSSG trials. FUNDING: Fondazione Città della Speranza, Association Léon Berard Enfant Cancéreux, Clinical Research Hospital Program (French Ministry of Health), and Cancer Research UK.

The effect of preoperative chemotherapy on histological subtyping and staging of Wilms tumors: The United Kingdom Children's Cancer Study Group (UKCCSG) Wilms tumor trial 3 (UKW3) experience.

BACKGROUND: Two principal approaches to Wilms tumor (WT) treatment are immediate surgery (IS) and preoperative chemotherapy (PCT), and both treatments use the risk-adapted approach that includes histological subclassification of the tumor, combined with additional prognostic factors. In the UKW3 trial, these two approaches were compared. The aim of the present study was to compare histological features between the two groups, to assess the impact of PCT on distribution of histological subtyping and staging and to evaluate whether PCT resulted in more staging discrepancies between local and central pathology review (CPR). MATERIALS AND METHODS: The cases were identified from the UKW3 trial database. The criteria for inclusion in the study were unilateral, nonmetastatic, nonanaplastic WTs, and submitted for CPR with an adequate number of slides. They were subclassified according to the NWTS and later the SIOP 9301 criteria. RESULTS: There were 244 WTs in the IS and 182 in the PCT group subclassified as follows: blastemal 86 (35%) vs 9 (5%), epithelial 34 (14%) vs 12 (7%), stromal 12 (5%) vs 25 (14%), mixed 112 (46%) vs 45 (25%), respectively, plus 40% regressive and 10% completely necrotic WTs in the PCT group. The differences between the two groups for blastemal and mixed types were statistically significant. In the PCT group, there was a significant decrease in stage III tumors. The discrepancies in staging between local and CPR were not significant. CONCLUSION: PCT significantly altered histological features and typing of WTs. It resulted in fewer stage III tumors, and staging discrepancies were equally represented in both groups.

Outcome of localized liver-bile duct rhabdomyosarcoma according to local therapy: A report from the European Paediatric Soft-Tissue Sarcoma Study Group (EpSSG)-RMS 2005 study.

OBJECTIVES: To evaluate the impact of local therapies on the outcome of patients with liver-bile duct rhabdomyosarcoma (LBDRMS). METHODS: Data of 30 patients included in the EpSSG-RMS 2005 study were analyzed. RESULTS: The median age at diagnosis was 3 years (11 months-8 years). All patients had non-alveolar histology. Fifteen patients had a tumor > 5 cm and six had enlarged regional lymph nodes on imaging. Eight patients (27%) had primary surgery (1 R0). Six of them received external beam radiotherapy (EBRT). All are in first complete remission (CR1) except one (R1, EBRT+ , local relapse, death). Six patients (20%) received EBRT without surgery: one had local relapse and died. Sixteen patients (53%) underwent delayed surgery, with 12 achieving R0 margins, which were higher than those in the primary surgery group (P = 0.003). Three patients with R0 margins received EBRT; one had a metastatic relapse and died. Nine patients with R0 resection did not receive EBRT, three relapsed locally (two deaths). Four R1 patients received additional EBRT without relapses. Local relapse occurred in two among 19 patients with EBRT and three among 11 without EBRT (P = 0.326). At a median follow-up of 61 months (48-84 months), five patients died; all had a tumor size > 5 cm (P = 0.01). The five-year overall survival was 85% (95% CI, 65-94), and event-free survival was 76% (95% CI, 54-89). CONCLUSION: This analysis did not show any significant difference in outcome between irradiated and nonirradiated patients. Local relapse in LBDRMS is related to initial tumor size and is often fatal.

Outcome and prognostic factors in pediatric malignant peripheral nerve sheath tumors: An analysis of the European Pediatric Soft Tissue Sarcoma Group (EpSSG) NRSTS-2005 prospective study.

BACKGROUND: Malignant peripheral nerve sheath tumors (MPNST) are rare tumors of childhood. The role of standard chemotherapy in unresectable MPNST is still unclear. We report the outcome and prognostic factors in the EpSSG risk-adapted prospective study for localized pediatric MPNST. METHODS: Patients were stratified into four treatment groups defined by surgical resection, tumor size, and tumor grade (G): (a) surgery-only group-resected tumors G1; (b) adjuvant radiotherapy group-R0/R1, G2 tumors; (c) adjuvant chemotherapy group-R0/R1, G3 tumors; and (d) neoadjuvant chemotherapy group-R2 resected tumors and/or nodal involvement. Chemotherapy consisted of four courses of ifosfamide-doxorubicin and two courses of ifosfamide concomitant with radiotherapy (50.4-54 Gy). RESULTS: Overall, the study included 51 patients. The 5-year event-free survival (EFS) and overall survival (OS) were 52.9% (95% confidence interval, 38.1-65.8) and 62.1% (46.7-74.3), respectively. The 5-year EFS was 92% (56.6-98.9) for treatment group 1 (N = 13), 33% (0.9-77.4) for treatment group 2 (N = 4), 29% (4.1-61.2) for treatment group 3 (N = 7), and 42% (23.1-60.1) for treatment group 4 (N = 27). Response rate to chemotherapy (partial response + complete response) in patients with measurable disease was 46%. The presence of neurofibromatosis type 1 (NF1; 51% of patients) was an independent poor prognostic factor for OS and EFS. CONCLUSION: The outcome for patients with resectable MPNST was excellent. Standard ifosfamide-doxorubicin for unresectable MPNST rendered the best reported outcome. Children with NF1 disease seem to have worse prognosis.

Addition of dose-intensified doxorubicin to standard chemotherapy for rhabdomyosarcoma (EpSSG RMS 2005): a multicentre, open-label, randomised controlled, phase 3 trial.

BACKGROUND: Rhabdomyosarcoma is an aggressive tumour that can develop in almost any part of the body. Doxorubicin is an effective drug against rhabdomyosarcoma, but its role in combination with an established multidrug regimen remains controversial. Therefore, we aimed to evaluate the possible benefit of early dose intensification with doxorubicin in patients with non-metastatic rhabdomyosarcoma. METHODS: We did a multicentre, open-label, randomised controlled, phase 3 trial involving 108 hospitals from 14 countries. We included patients older than 6 months but younger than 21 years with a pathologically proven diagnosis of rhabdomyosarcoma. We assigned each patient to a specific subgroup according to the EpSSG stratification system. Those with embryonal rhabdomyosarcoma incompletely resected and localised at unfavourable sites with or without nodal involvement, or those with alveolar rhabdomyosarcoma without nodal involvement were considered at high risk of relapse. These high-risk patients were randomly assigned (1:1) to receive either nine cycles of IVA (ifosfamide 3 g/m2 given as a 3-h intravenous infusion on days 1 and 2, vincristine 1·5 mg/m2 weekly during the first 7 weeks then only on day 1 of each cycle [given as a single intravenous injection], and dactinomycin 1·5 mg/m2 on day 1 given as a single intravenous injection) or four cycles of IVA with doxorubicin 30 mg/m2 given as a 4-h intravenous infusion on days 1 and 2 followed by five cycles of IVA. The interval between cycles was 3 weeks. Randomisation was done using a web-based system and was stratified (block sizes of four) by enrolling country and risk subgroup. Neither investigators nor patients were masked to treatment allocation. The primary endpoint was 3-year event-free survival assessed by the investigator at each centre in the intention-to-treat population. Patients who received at least one dose of study treatment were considered in the safety analysis. In agreement with the independent data monitoring committee, the study was closed to patient entry on Dec 16, 2013, after futility analysis. This trial is registered with EudraCT, number 2005-000217-35, and is currently in follow-up. FINDINGS: Between Oct 1, 2005, and Dec 16, 2013, 484 patients were randomly assigned to receive each chemotherapy regimen (242 in the IVA group and 242 in the IVA plus doxorubicin group). Median follow-up was 63·9 months (IQR 44·6-78·9). The 3-year event-free survival was 67·5% (95% CI 61·2-73·1) in the IVA plus doxorubicin group and 63·3% (56·8-69·0) in the IVA group (hazard ratio 0·87, 95% CI 0·65-1·16; p=0·33). Grade 3-4 leucopenia (232 [93%] of 249 patients in the IVA plus doxorubicin group vs 194 [85%] of 227 in the IVA group; p=0·0061), anaemia (195 [78%] vs 111 [49%]; p<0·0001), thrombocytopenia (168 [67%] vs 59 [26%]; p<0.0001), and gastrointestinal adverse events (78 [31%] vs 19 [8%]; p<0·0001) were significantly more common in the IVA plus doxorubicin group than in the IVA group. Grade 3-5 infections (198 [79%] vs 128 [56%]; p<0·0001) were also significantly more common in the IVA plus doxorubicin group than in the IVA group, in which one patient had grade 5 infection. Two treatment-related deaths were reported (one patient developed septic shock and one affected by Goldenhar syndrome developed intractable seizures) in the IVA plus doxorubicin group, both occurring after the first cycle of treatment, and none were reported in the IVA group. INTERPRETATIONS: The addition of dose-intensified doxorubicin to standard IVA chemotherapy did not show a significant improvement in the outcome of patients with high-risk non-metastatic rhabdomyosarcoma. Therefore, the IVA chemotherapy regimen should remain the standard of care for patients with localised rhabdomyosarcoma in Europe. FUNDING: Fondazione Città della Speranza, Italy, and the Association Léon Berard Enfant Cancéreux, France.

Prognostic relevance of early radiologic response to induction chemotherapy in pediatric rhabdomyosarcoma: A report from the International Society of Pediatric Oncology Malignant Mesenchymal Tumor 95 study.

BACKGROUND: Early response to induction chemotherapy is used in current European guidelines to evaluate the efficacy of chemotherapy and subsequently to adapt treatment in pediatric patients with rhabdomyosarcoma (RMS). However, existing literature on the prognostic value of early radiologic response on survival is contradictory; here the prognostic value is analyzed with data from the International Society of Pediatric Oncology (SIOP) Malignant Mesenchymal Tumor 95 (MMT-95) study. METHODS: This study examined 432 Intergroup Rhabdomyosarcoma Study Grouping III (macroscopic residue) patients enrolled in the SIOP MMT-95 study with a response assessment after 3 courses of chemotherapy (a 2-dimensional assessment). Patients with progressive disease (PD) after 3 courses of chemotherapy were excluded (n = 7). Failure-free survival (FFS) and overall survival (OS), calculated with the Kaplan-Meier method, were compared for 3 groups (complete response [CR]/partial response [PR], objective response [OR], and no response [NR]). The prognostic impact of early response was assessed through the calculation of Cox proportional hazards. RESULTS: After 3 courses of chemotherapy, 85.2% of the patients had CR/PR, 8.6% had OR, and 6.3% had NR. For all patients, the 5-year FFS and OS rates were 60% (95% confidence interval [CI], 56%-65%) and 74% (95% CI, 70%-78%), respectively. However, a Cox proportional hazards regression analysis revealed no significant difference in FFS or OS between the response groups. The adjusted hazard ratios for an OR and NR were 1.09 (95% CI, 0.63-1.88) and 0.81 (95% CI, 0.39-1.67), respectively, for FFS and 0.91 (95% CI, 0.47-1.76) and 1.27 (95% CI, 0.61-2.64), respectively, for OS. CONCLUSIONS: No evidence was found for the idea that early radiologic response to chemotherapy is prognostic for survival for patients with RMS. Treatment adaptation based on early response (except for patients with PD) should, therefore, no longer be incorporated into future studies. Cancer 2018;124:1016-24. © 2017 American Cancer Society.

Alveolar soft part sarcoma in children and adolescents: The European Paediatric Soft Tissue Sarcoma study group prospective trial (EpSSG NRSTS 2005).

BACKGROUND: As alveolar soft part sarcomas (ASPS) are rare with no prospective series within pediatric sarcoma trials, the European Paediatric Soft Tissue Sarcoma Study Group (EpSSG) examined the clinical data and outcomes of ASPS enrolled in a multinational study of nonrhabdomyosarcoma soft tissue sarcomas (NRSTS). PATIENTS AND METHODS: Twenty-two patients with ASPS were enrolled into the EpSSG NRSTS 2005 study. After surgical resection, subsequent treatment depended on the stratification of patients for completeness of resection and Intergroup Rhabdomyosarcoma Study (IRS) stage, size, and French Federation of Cancer Centres Sarcoma Group (FNCLCC) grade. Chemotherapy using ifosfamide and doxorubicin was performed in IRS group III. Radiotherapy was performed in IRS groups II and III, and FNCLCC grades 2 and 3 tumors. RESULTS: The median age at diagnosis was 11.5 years (range 2.7-17.5 years). The majority in the series had localized disease (20), with small IRS I tumors (12), and in total 19 had surgical resection upfront. Of the four patients who received conventional chemotherapy, there were no responses. Three of 20 patients with localized tumors and all metastatic patients developed metastases. The median follow up of patients with localized disease is 61.7 months (range 25.7-135.5 months) from diagnosis. The 5-year event-free survival is 94.7% (95% confidence interval: 68.1-99.2), and therefore the overall survival (OS) is 100%. CONCLUSION: This report demonstrates the ability to run prospective pediatric studies in NRSTS in multiple European countries, despite the small numbers of ASPS patients. We can conclude that for the majority with small resected tumors, there were few events and no deaths.

Impact of fusion gene status versus histology on risk-stratification for rhabdomyosarcoma: Retrospective analyses of patients on UK trials.

BACKGROUND: Long-term toxicities from current treatments are a major issue in paediatric cancer. Previous studies, including our own, have shown prognostic value for the presence of PAX3/7-FOXO1 fusion genes in rhabdomyosarcoma (RMS). It is proposed to introduce PAX3/7-FOXO1 positivity as a component of risk stratification, rather than alveolar histology, in future clinical trials. PROCEDURE: To assess the potential impact of this reclassification, we have determined the changes to risk category assignment of 210 histologically reviewed patients treated in the UK from previous malignant mesenchymal tumour clinical trials for non-metastatic RMS based on identification of PAX3/7-FOXO1 by fluorescence in situ hybridisation and/or reverse transcription PCR. RESULTS: Using fusion gene positivity in the current risk stratification would reassign 7% of patients to different European Paediatric Soft Tissue Sarcoma Study Group (EpSSG) risk groups. The next European trial would have 80% power to detect differences in event-free survival of 15% over 10 years and 20% over 5 years in reassigned patients. This would decrease treatment for over a quarter of patients with alveolar histology tumours that lack PAX3/7-FOXO1. CONCLUSIONS: Fusion gene status used in stratification may result in significant numbers of patients benefitting from lower treatment-associated toxicity. Prospective testing to show this reassignment maintains current survival rates is now required and is shown to be feasible based on estimated recruitment to a future EpSSG trial. Together with developing novel therapeutic strategies for patients identified as higher risk, this may ultimately improve the outcome and quality of life for patients with RMS.

Paratesticular rhabdomyosarcoma in children and adolescents-Outcome and patterns of relapse when utilizing a nonsurgical strategy for lymph node staging: Report from the International Society of Paediatric Oncology (SIOP) Malignant Mesenchymal Tumour 89 and 95 studies.

PURPOSE: To report the results from International Society of Pediatric Oncology (SIOP) Malignant Mesenchymal Tumors studies (MMT 89 and 95) of males with nonmetastatic paratesticular rhabdomyosarcoma. METHODS: From 1989 to 2003, 159 patients were included. Radical inguinal orchidectomy was recommended, but retroperitoneal lymph node (LN) assessment was based on imaging alone. The treatment was stratified by stage (SIOP tumor-node-metastasis staging system) and histology. RESULTS: Median age at presentation was 5.6 years (range 0.3-17.6) and 120 patients were of <10 years (75%). Patients ≥10 years had tumors of >5 cm more frequently compared to patients of <10 years (54% vs. 22%, P = 0.0004). The 5- year overall and progression-free survivals were 94% and 83%, respectively. Seventy-eight percent of relapses occurred in the retroperitoneal LN. Thirty-one percent of stage N0 patients of age ≥10 years developed node relapse, compared with 8% of N0 patients aged <10 years (P = 0.0005). CONCLUSIONS: Older patients with paratesticular rhabdomyosarcoma have a significant risk of LN relapse. These results support a surgical approach to LN staging in this subgroup of patients.

Ventricular metastatic dissemination of a paediatric craniopharyngioma: case report and literature review.

Distant intraventricular metastasis is extremely rare in childhood craniopharyngioma. Here, we report the isolated posterior ventricular recurrence of an adamantinomatous craniopharyngioma, in a child previously treated with surgery and proton beam therapy for local progression. The importance of surveillance imaging is highlighted, while specific surgical approaches and techniques are considered.

Pediatric intracranial clear cell meningioma associated with a germline mutation of SMARCE1: a novel case.

PURPOSE: Intracranial clear cell meningioma (CCM) represents a rare and potentially more aggressive subgroup of meningioma that is observed more frequently in children and adolescents. Despite its characterization as a histological entity, there is little evidence identifying tumorigenic etiologies. Recently, a novel mutation in SMARCE1, encoding a subunit of the SWI/SNF chromatin remodeling complex, was identified in a cohort of spinal CCMs. To date, no intracranial CCM has been subjected to analysis. METHODS: We report the case of an isolated intracranial CCM in a 14-year-old girl. Gross total resection was achieved following a two-stage approach with no evidence of tumor recurrence 8 months following presentation. RESULTS: Exon sequencing identified a germline mutation in SMARCE1, which was also present in tumor DNA. Extensive literature review confirmed our study is the first to seek and report a genetic anomaly for childhood intracranial CCMs outside of the NF2 gene locus, and the first to make an association between a germline SMARCE1 mutation and childhood intracranial CCMs. CONCLUSIONS: Together with the previous description of SMARCE1 mutations in spinal CCMs, our report suggests that SMARCE1 aberrations may be implicated in establishing a clear cell histology irrespective of meningioma location. We would advocate that, where feasible, genetic sequencing is performed on future new cases of childhood neuraxial CCMs and includes interrogation of the SMARCE1 gene.

Primary cerebral histiocytic sarcoma in childhood: a case report of protracted survival and review of the literature.

INTRODUCTION: Histiocytic sarcoma (HS) of the central nervous system (CNS) is exceptionally rare in pediatric patients, historically associated with an exceptionally poor prognosis. Here, the authors present a novel case of protracted progression-free survival following surgical excision, radiotherapy and temozolomide. CASE REPORT: A 15-year-old Caucasian girl presented with a two-month history of headache, diplopia, vomiting, lethargy, weight loss and neurocognitive deterioration without gross neurological deficit on physical examination. Magnetic resonance imaging (MRI) of the brain identified a 5.8 × 4.7 × 4.0 cm lesion in the right frontal lobe with associated mass effect and no dissemination. Following two surgical procedures, gross total resection was achieved. Histology and immunohistochemistry confirmed HS, with strong CD163 staining. After focal radiotherapy with concomitant temozolomide, and a further seven cycles of temozolomide, the patient made an excellent recovery and is recurrence free without neurological deficit, 23 months following presentation. CONCLUSION: To the authors' knowledge, this is the first incidence of a prolonged, functionally preserved and recurrence-free outcome following a diagnosis of HS within the CNS of a pediatric patient. We suggest early diagnosis prior to dissemination and complete surgical resection as an essential treatment goal in this rare disease.

Conservative approach in localised rhabdomyosarcoma of the bladder and prostate: results from International Society of Paediatric Oncology (SIOP) studies: malignant mesenchymal tumour (MMT) 84, 89 and 95.

BACKGROUND: The three sequential SIOP MMT studies provide the largest dataset available to date, to define the patient and tumour characteristics, treatment modalities and event-free and overall survival for children with non metastatic rhabdomyosarcoma (RMS) of the bladder and/or prostate (BP). PROCEDURE: The combined dataset of 172 patients with BP RMS treated on the SIOP MMT 84, 89 and 95 studies was reviewed to determine tumour characteristics, details of treatment and outcome. RESULTS: Median age at diagnosis was 2.5 years (range 2 months-17.8 years) and 138 (79%) were males. Median follow-up was 11.4 years (range 3 months-22 years). The 5-year overall survival of the combined cohort was 77% (CI 70-83%). The 5-year event-free survival was 63% and included 7 patients (4%) who did not achieve complete remission (CR), and 57 (33%) who relapsed. Age ≥ 10 years (RR 3.7) and alveolar pathology (RR 3.3) were identified as independent prognostic factors on multivariate analysis. Fifty-nine (50%) of the 119 survivors were cured without significant local therapy, improving from 31% in MMT84 study to 61% in MMT95 study. CONCLUSION: The clinical strategy of the MMT studies aims to minimise the burden of therapy whilst maintaining survival rates. Overall survival is comparable to that of other international groups, despite the lower use of radiotherapy and or radical surgery, although number of events experienced is higher. Further assessment of the late effects of therapy is required to confirm whether this approach results in lower morbidity in the long-term.

Inflammatory myofibroblastic tumors following the treatment of malignancy in childhood: case reports.

Inflammatory myofibroblastic tumors (IMT) are rare, mostly benign soft tissue tumors. Occurring mainly in children the presentation, clinical features, and diagnostic dilemmas raised are well reported. Here we describe 4 patients diagnosed with IMT after the treatment of childhood cancer, and review the literature regarding IMT and malignancy. Discussing them in this context raises clinical questions; Are these tumors incidental or a consequence of treatment? Are they more common than we think and are any miss-diagnosed as tumor recurrence? This paper aims to raise awareness of IMT as diagnostic possibilities after treatment for childhood malignancies.