European Paediatric Soft Tissue Sarcoma Research Articles

Brachytherapy for rhabdomyosarcoma: Survey of international clinical practice and development of guidelines

Background and purposeThe purpose of this study was to address the lack of published data on the use of brachytherapy in pediatric rhabdomyosarcoma by describing current practice as starting point to develop consensus guidelines. Materials and methodsAn international expert panel on the treatment of pediatric rhabdomyosarcoma comprising 24 (pediatric) radiation oncologists, brachytherapists and pediatric surgeons met for a Brachytherapy Workshop hosted by the European paediatric Soft tissue Sarcoma Study Group (EpSSG). The panel’s clinical experience, the results of a previously distributed questionnaire, and a review of the literature were presented. ResultsThe survey indicated the most common use of brachytherapy to be in combination with tumor resection, followed by brachytherapy as sole local therapy modality. HDR was increasingly deployed in pediatric practice, especially for genitourinary sites. Brachytherapy planning was mostly by 3D imaging based on CT. Recommendations for patient selection, treatment requirements, implant technique, delineation, dose prescription, dose reporting and clinical management were defined. ConclusionsConsensus guidelines for the use of brachytherapy in pediatric rhabdomyosarcoma have been developed through multicenter collaboration establishing the basis for future work. These have been adopted for the open EpSSG overarching study for children and adults with Frontline and Relapsed RhabdoMyoSarcoma (FaR-RMS).

Frontline and Relapsed Rhabdomyosarcoma (FAR-RMS) Clinical Trial: A Report from the European Paediatric Soft Tissue Sarcoma Study Group (EpSSG).

The Frontline and Relapsed Rhabdomyosarcoma (FaR-RMS) clinical trial is an overarching, multinational study for children and adults with rhabdomyosarcoma (RMS). The trial, developed by the European Soft Tissue Sarcoma Study Group (EpSSG), incorporates multiple different research questions within a multistage design with a focus on (i) novel regimens for poor prognostic subgroups, (ii) optimal duration of maintenance chemotherapy, and (iii) optimal use of radiotherapy for local control and widespread metastatic disease. Additional sub-studies focusing on biological risk stratification, use of imaging modalities, including [18F]FDG PET-CT and diffusion-weighted MRI imaging (DWI) as prognostic markers, and impact of therapy on quality of life are described. This paper forms part of a Special Issue on rhabdomyosarcoma and outlines the study background, rationale for randomisations and sub-studies, design, and plans for utilisation and dissemination of results.

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.

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. 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. The EFS and overall survival rates at 5years 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 ageat 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. 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.

Indeterminate pulmonary nodules in non-rhabdomyosarcoma soft tissue sarcoma: A study of the European paediatric Soft Tissue Sarcoma Study Group.

The aim of this study was to assess the clinical impact of indeterminate pulmonary nodules (no more than four pulmonary nodules of less than 5mm or one nodule measuring between 5 and less than 10mm by computed tomography [CT]) in children and adolescents with adult-type non-rhabdomyosarcoma soft tissue sarcoma (NRSTS) at diagnosis. Patients with NRSTS treated in 11 centers as part of the European paediatric Soft Tissue Sarcoma Study Group (EpSSG) were retrospectively assessed. Local radiologists, blinded to clinical information except for patients' age and tumor histotype, reviewed the chest CT at diagnosis and filled out a case report form. Because patients with or without indeterminate nodules in the EpSSG NRSTS 2005 study received the same type of treatment, event-free survival (EFS) and overall survival (OS) between groups by log-rank test were compared. Overall, 206 patients were examined: 109 (52.9%) were without any nodules, 78 (38%) had at least one indeterminate nodule, and 19 (9.2%) had nodules meeting the definition of metastases, which were then considered to be misclassified and were excluded from further analyses. Five-year EFS was 78.5% (95% CI, 69.4%-85.1%) for patients without nodules and 69.6% (95% CI, 57.9%-78.7%) for patients with indeterminate nodules (p=.135); 5-year OS was 87.4% (95% CI, 79.3%-92.5%) and 79.0% (95% CI, 67.5%-86.8%), respectively (p=.086). This study suggests that survival does not differ in otherwise nonmetastatic patients with indeterminate pulmonary nodules compared to nonmetastatic patients without pulmonary nodules. Radiologists should be aware of the classification of indeterminate pulmonary nodules in non-rhabdomyosarcoma soft tissue sarcomas and use it in their reports. More than a third of patients with non-rhabdomyosarcoma soft tissue sarcoma can be affected by indeterminate pulmonary nodules. Indeterminate pulmonary nodules do not significantly affect the overall survival of pediatric patients with non-rhabdomyosarcoma soft tissue sarcoma.

Quantitative diffusion-weighted MRI response assessment in rhabdomyosarcoma: an international retrospective study on behalf of the European paediatric Soft tissue sarcoma Study Group Imaging Committee

ObjectiveTo investigate the feasibility of diffusion-weighted magnetic resonance imaging (DW-MRI) as a predictive imaging marker after neoadjuvant chemotherapy in patients with rhabdomyosarcoma.Material and methodsWe performed a multicenter retrospective study including pediatric, adolescent and young adult patients with rhabdomyosarcoma, Intergroup Rhabdomyosarcoma Study group III/IV, treated according to the European paediatric Soft tissue sarcoma Study Group (EpSSG) RMS2005 or MTS2008 studies. DW-MRI was performed according to institutional protocols. We performed two-dimensional single-slice tumor delineation. Areas of necrosis or hemorrhage were delineated to be excluded in the primary analysis. Mean, median and 5th and 95th apparent diffusion coefficient (ADC) were extracted.ResultsOf 134 included patients, 82 had measurable tumor at diagnosis and response and DW-MRI scans of adequate quality and were included in the analysis. Technical heterogeneity in scan acquisition protocols and scanners was observed. Mean ADC at diagnosis was 1.1 (95% confidence interval [CI]: 1.1–1.2) (all ADC expressed in * 10−3 mm2/s), versus 1.6 (1.5–1.6) at response assessment. The 5th percentile ADC was 0.8 (0.7–0.9) at diagnosis and 1.1 (1.0–1.2) at response. Absolute change in mean ADC after neoadjuvant chemotherapy was 0.4 (0.3–0.5). Exploratory analyses for association between ADC and clinical parameters showed a significant difference in mean ADC at diagnosis for alveolar versus embryonal histology. Landmark analysis at nine weeks after the date of diagnosis showed no significant association (hazard ratio 1.3 [0.6–3.2]) between the mean ADC change and event-free survival.ConclusionA significant change in the 5th percentile and the mean ADC after chemotherapy was observed. Strong heterogeneity was identified in DW-MRI acquisition protocols between centers and in individual patients.Graphical

Outcomes in lung-only metastatic rhabdomyosarcoma: An analysis of data from the European paediatric Soft tissue sarcoma Study Group MTS 2008 study

PurposePatients with metastatic rhabdomyosarcoma (MTS RMS) and lung as the only metastatic site have better reported outcomes than other patients with MTS RMS. We analysed patients with lung-only MTS RMS receiving standard treatment within the EpSSG MTS 2008 protocol. Patients and methodsPreviously untreated patients aged< 21 years with MTS RMS received standard induction chemotherapy with radiotherapy (RT) and/or surgery to the primary site and RT recommended to all metastatic sites. Clinical characteristics, treatment and outcomes of patients with lung-only MTS RMS were compared to lung + other site and other site MTS RMS. ResultsAmong 270 patients with MTS RMS, 59 (22%) had lung-only metastatic disease, 68 (25%) in lung + other and 143 (53%) in other sites. 3-yr Event Free Survival (EFS) and Overall Survival (OS) for lung-only MTS RMS were 40% (95%CI 27–53%) and 60% (95%CI 46–71%). Although 3-yr OS for lung-only MTS RMS was significantly better than lung + other (35%; 95% CI 24–47%) and other (49%; 95% CI 40–57%) sites (p = 0.0382), EFS and OS adjusted for known clinical (Oberlin) risk factors, did not differ between the groups. 3-year EFS was significantly higher in patients with lung-only MTS who received RT to the lungs (RT, n = 26, EFS 56%, 95% CI 35–73%; no RT, n = 24, EFS 33%, 95% CI 16–52%, p = 0.0435). ConclusionsBetter outcomes for lung-only MTS RMS seem to be determined by the presence of fewer clinical risk factors. Whole lung radiotherapy continues to be recommended in patients with lung-only MTS RMS.

Intra-abdominal desmoplastic small round cell tumor: The European pediatric Soft tissue sarcoma Study Group (EpSSG) experience.

This study describes the clinical findings of a consecutive series of pediatric and adolescent patients with a diagnosis of intra-abdominal desmoplastic small round cell tumor (DSRCT) prospectively enrolled in European pediatric Soft tissue sarcoma Study Group (EpSSG) protocols: the BERNIE study, the EpSSG MTS 2008 study, and the EpSSG NRSTS 2005 study. Patients aged less than 21years with a diagnosis of DSRCT arising in the abdomen were included. All trials recommended a multimodal approach including intensive multidrug chemotherapy and loco-regional treatment with surgery and/or radiotherapy whenever possible. The analysis included 32 cases (median age 13.7years, male:female ratio 1.5:1). Three patients had localized tumors, seven had regionally disseminated disease, and 22 extraperitoneal metastases. All but one patient received multidrug chemotherapy and 11 had maintenance chemotherapy. Loco-regional treatment consisted of surgery only in seven cases, surgery plus adjuvant radiotherapy in 10, and radiotherapy only in six. Among the 17 cases who had radiotherapy, six had irradiation of the primary site, 10 had whole abdominopelvic radiotherapy plus boost to macroscopic residual disease, and one had irradiation to lung metastases only. With a median follow-up of 76months (range: 18-124months), 5-year event-free and overall survivals were 19.7% and 21.0%, respectively. Event-free survival was significantly worse for patients who did not receive loco-regional treatment (p-value .007). The study confirmed that the outcome of patients with DSRCT remains dismal and did not improve over recent years despite an intensive multimodal treatment approach.

Metastatic adult-type non-rhabdomyosarcoma soft tissue sarcomas in children and adolescents: A cohort study from the European paediatric Soft tissue sarcoma Study Group.

Limited data exist on the clinical behavior of pediatric non-rhabdomyosarcoma soft tissue sarcomas (NRSTS) with distant metastases at onset, and a clear standard of care has not yet been defined. This cohort study reports on pediatric adult-type metastatic NRSTS enrolled in two concurrent prospective European studies, i.e., the randomized BERNIE study and the single-arm MTS 2008 study developed by the European paediatric Soft tissue sarcoma Study Group. Treatment programs were originally designed for patients with metastatic rhabdomyosarcoma, i.e., nine courses of multidrug chemotherapy (with or without bevacizumab in the BERNIE study), followed by 12 cycles of maintenance therapy, whereas radiotherapy and/or surgery (on primary tumor and/or metastases) were delayed until after seven courses of chemotherapy had been administered. The study included 61 patients <21years old treated from July 2008 to December 2016. The lung was the site of metastases in 75% of the cases. All patients received multi-agent chemotherapy, 44% had local therapy to primary tumor, and 18% had treatment of metastases. Median time to progression/relapse was 6months. A high rate of tumor progression was observed during the initial part of the chemotherapy program. With a median follow-up of 41.5months (range, 2-111months), 3-year event-free survival and overall survival were 15.4% (95% confidence interval [CI], 7.6-25.7) and 34.9% (95% CI, 22.7-47.5), respectively. There were no statistically significant differences in outcome depending on the type of treatment administered. The study confirmed the overall poor outcome for patients with metastatic NRSTS, whose treatment remains a challenge. Pediatric non-rhabdomyosarcoma soft tissue sarcomas form a heterogeneous group of rare tumors. Although recent international studies have defined the standard of care for patients with localized disease, limited data are available on the clinical behavior of patients with distant metastases. This study on 61 metastatic cases treated on two prospective European protocols confirms that the chances of survival of such patients are often dismal and a standard treatment is still lacking.

Biological Role and Clinical Implications of MYOD1L122R Mutation in Rhabdomyosarcoma

Major progress in recent decades has furthered our clinical and biological understanding of rhabdomyosarcoma (RMS) with improved stratification for treatment based on risk factors. Clinical risk factors alone were used to stratify patients for treatment in the European Pediatric Soft Tissue Sarcoma Study Group (EpSSG) RMS 2005 protocol. The current EpSSG overarching study for children and adults with frontline and relapsed rhabdomyosarcoma (FaR-RMS NCT04625907) includes FOXO1 fusion gene status in place of histology as a risk factor. Additional molecular features of significance have recently been recognized, including the MYOD1L122R gene mutation. Here, we review biological information showing that MYOD1L122R blocks cell differentiation and has a MYC-like activity that enhances tumorigenesis and is linked to an aggressive cellular phenotype. MYOD1L122R mutations can be found together with mutations in other genes, such as PIK3CA, as potentially cooperating events. Using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, ten publications in the clinical literature involving 72 cases were reviewed. MYOD1L122R mutation in RMS can occur in both adults and children and is frequent in sclerosing/spindle cell histology, although it is also significantly reported in a subset of embryonal RMS. MYOD1L122R mutated tumors most frequently arise in the head and neck and extremities and are associated with poor outcome, raising the issue of how to use MYOD1L122R in risk stratification and how to treat these patients most effectively.

Nonmetastatic Rhabdomyosarcoma in Children and Adolescents: Overall Results of the European Pediatric Soft Tissue Sarcoma Study Group RMS2005 Study.

Clinical trials frequently include multiple end points that mature at different times. The initial report, typically based on the primary end point, may be published when key planned co-primary or secondary analyses are not yet available. Clinical Trial Updates provide an opportunity to disseminate additional results from studies, published in JCO or elsewhere, for which the primary end point has already been reported.The RMS2005 study included two phase III randomized trials for high-risk (HR) and observational trials for low (LR), standard (SR), and very high-risk (VHR) patients who have been partially reported. Herein, we present a comprehensive report of results achieved for the complete unselected nonmetastatic cohort and analyze the evolution of treatment in comparison with previous European protocols. After a median follow-up of 73.1 months, the 5-year event-free survival (EFS) and overall survival (OS) of the 1,733 patients enrolled were 70.7% (95% CI, 68.5 to 72.8) and 80.4% (95% CI, 78.4 to 82.3), respectively. The results by subgroup: LR (80 patients) EFS 93.7% (95% CI, 85.5 to 97.3), OS 96.7% (95% CI, 87.2 to 99.2); SR (652 patients) EFS 77.4% (95% CI, 73.9 to 80.5), OS 90.6% (95% CI, 87.9 to 92.7); HR (851 patients) EFS 67.3% (95% CI, 64.0 to 70.4), OS 76.7% (95% CI, 73.6 to 79.4); and VHR (150 patients) EFS 48.8% (95% CI, 40.4 to 56.7), OS 49.7% (95% CI, 40.8 to 57.9). The RMS2005 study demonstrated that 80% of children with localized rhabdomyosarcoma could be long-term survivors. The study has established the standard of care across the European pediatric Soft tissue sarcoma Study Group countries with the confirmation of a 22-week vincristine/actinomycin D regimen for LR patients, the reduction of the cumulative ifosfamide dose in the SR group, and for HR disease, the omission of doxorubicin and the addition of maintenance chemotherapy.

Imaging in rhabdomyosarcoma: a patient journey

Rhabdomyosarcoma, although rare, is the most frequent soft tissue sarcoma in children and adolescents. It can present as a mass at nearly any site in the body, with most common presentations in the head and neck, genitourinary tract and extremities. The optimal diagnostic approach and management of rhabdomyosarcoma require a multidisciplinary team with multimodal treatment, including chemotherapy and local therapy. Survival has improved over the last decades; however, further improvement in management is essential with current 5-year overall survival ranging from 35% to 100%, depending on disease and patient characteristics. In the full patient journey, from diagnosis, staging, management to follow-up after therapy, the paediatric radiologist and nuclear physician are essential members of the multidisciplinary team. Recently, guidelines of the European paediatric Soft tissue sarcoma Study Group, the Cooperative Weichteilsarkom Studiengruppe and the Oncology Task Force of the European Society of Paediatric Radiology (ESPR), in an ongoing collaboration with the International Soft-Tissue Sarcoma Database Consortium, provided guidance for high-quality imaging. In this educational paper, given as a lecture during the 2022 postgraduate ESPR course, the multi-disciplinary team of our national paediatric oncology centre presents the journey of two patients with rhabdomyosarcoma and discusses the impact on and considerations for the clinical (paediatric) radiologist and nuclear physician. The key learning points of the guidelines and their implementation in clinical practice are highlighted and up-to-date insights provided for all aspects from clinical suspicion of rhabdomyosarcoma and its differential diagnosis, to biopsy, staging, risk stratification, treatment response assessment and follow-up.

The significance of margins in pediatric Non-Rhabdomyosarcoma soft tissue sarcomas: Consensus on surgical margin definition harmonization from the INternational Soft Tissue SaRcoma ConsorTium (INSTRuCT).

Margin status following surgery in children, adolescents, and young adults with soft tissue sarcomas is controversial and has been defined differently by various specialties, with definitions changing over time and by cooperative group. The International Soft Tissue Sarcoma Consortium (INSTRuCT) is a collaboration of the Children's Oncology Group (COG) Soft Tissue Sarcoma Committee, European pediatric Soft Tissue sarcoma Study Group (EpSSG), and the European Cooperative Weichteilsarkom Studiengruppe (CWS) devoted to improving patient outcomes by pooling and mining cooperative group clinical trial data. The INSTRuCT non-rhabdomyosarcoma soft tissue sarcoma (NRSTS) working group aimed to develop international harmonized recommendations regarding surgical margin assessment and definitions in children and adolescents with soft tissue tumors. This review addresses accepted principles and areas of controversy, including the perspectives of surgeons, pathologists, radiation oncologists, and pediatric oncologists, to develop a framework for building common guidelines for future research.

Time to broaden the eligibility criteria in paediatric oncology trials? An analysis of patients with rhabdomyosarcoma non-eligible to the EpSSG RMS2005 trial

PurposeClinical trials include a series of eligibility and exclusion criteria that define the study population to reduce inter-patient heterogeneity and increase safety. Little is known about children with oncological diseases excluded from trials because they do not satisfy these criteria. We analysed the eligibility criteria adopted in the European paediatric Soft tissue sarcoma Study Group RMS2005 study and the survival of non-eligible patients.Patients and methodsRMS2005 run from 10/2005–12/2016. Eligibility criteria were age ≤ 25 years; pathologically proven diagnosis of rhabdomyosarcoma (RMS); no evidence of metastases; no pre-treatment; no pre-existing conditions preventing treatment; no previous malignant tumours and an interval between diagnostic surgery and the start of treatment ≤ 8 weeks. Clinical characteristics, 5-year progression-free survival (PFS), and overall survival (OS) were analysed for eligible and non-eligible patients.ResultsThe 79 non-eligible patients (4.3% of registered patients) were older than eligible patients (p<0.0001), with RMS arising in favourable sites (p = 0.004) and completely resected at diagnosis (p<0.0001). PFS for non-eligible vs. eligible patients was 67.1% (95%CI 55.3–76.5) vs. 71.5% (95%CI 69.3–73.6) (p = 0.23) and OS 77.1% (95%CI 65.7–85.1) vs. 80.4% (95%CI 78.4–82.3) (p = 0.12), respectively. Patients with a delayed start of treatment or pre-treated had significantly better PFS than those with a pre-existing condition (p = 0.0004).Conclusionnon-eligible patients data should be systematically collected. This will be important to confirm that trial eligibility criteria for patients with RMS could be modified without jeopardising results and increasing study enrolment and generalisability of results.

Using Evidence-Based Medicine to Support Clinical Decision-Making in RMS

The foundations of evidence-based practice are the triad of patient values and preferences, healthcare professional experience, and best available evidence, used together to inform clinical decision-making. Within the field of rhabdomyosarcoma, collaborative groups such as the European Paediatric Soft Tissue Sarcoma Group (EpSSG) have worked to develop evidence to support this process. We have explored many of the key research developments within this review, including patient and public involvement, decision-making research, research into areas other than drug development, core outcome sets, reporting and dissemination of research, evidence synthesis, guideline development and clinical decision rules, research of research methodologies, and supporting research in RMS.

Metastatic rhabdomyosarcoma with exclusive distant lymph node involvement: A European Pediatric Soft tissue sarcoma Study Group (EpSSG) report.

The prognosis of patients with metastatic rhabdomyosarcoma (RMS) is not uniformly poor. Tumors with nodal involvement beyond the first lymph node station are currently considered to have distant metastases. The aim of this study is to evaluate the characteristics and outcome of RMS patients with distal nodal involvement as the only site of metastasis. This study included all patients with a diagnosis of RMS and distant nodal involvement as the only metastatic site, enrolled in the European Pediatric Soft tissue sarcoma Study Group (EpSSG) protocols. Treatment comprised chemotherapy, surgery, and/or radiotherapy. The main outcome measures were event-free survival (EFS) and overall survival (OS). A total of 22 patients (median age 7.1years, range 1.4-16.7) fit the inclusion criteria. The extremities were the most common primary tumor site (59%). Twenty-one patients had regional and distant nodal involvement, 12 were PAX3/7-FOXO1 positive. Twenty patients had radiotherapy including 16 to the nodal metastatic area. After a median follow-up of 53.9months (range 22.8-110.5), 15 patients remain in complete remission, seven had progressive disease or relapse, and six of them died. The 3-year EFS and OS were 67.1% (95% confidence interval [CI]: 42.9-82.9) and 71.9% (95% CI: 47.7-86.3), respectively. Patients with fusion-negative tumors had better outcomes than those with fusion-positive tumors (3-year EFS 100% vs. 46.6%; p=.04). In our experience, patients with RMS and distant lymph node involvement as the only site of metastasis present an outcome superior than other metastatic patients and comparable to patients with locoregional nodal involvement. In particular, excellent outcomes were seen in the limited number of patients with fusion-negative tumors.

Malignant ectomesenchymoma in children: The European pediatric Soft tissue sarcoma Study Group experience.

Malignant ectomesenchymoma (MEM) is an extremely rare soft tissue tumor typical of young children, currently included in the category of skeletal muscle malignancies and characterized by a neuroblastic component. This study describes a series of 10 patients prospectively registered in the European paediatric Soft tissue sarcoma Study Group (EpSSG) database Of the 10 cases, seven had an initial local diagnosis of rhabdomyosarcoma. All patients received chemotherapy according to rhabdomyosarcoma strategy, four had radiotherapy. Overall, six patients were alive in first remission, two in second remission and one after second tumor. Only the patient with initially metastatic tumor died of disease.

Rhabdomyosarcoma with unknown primary tumor site: A report from European pediatric Soft tissue sarcoma Study Group (EpSSG).

Rhabdomyosarcoma (RMS) is an aggressive malignancy, and 20% of children present with metastases at diagnosis. Patients presenting with disseminated disease very occasionally have no clear evidence of a primary tumor mass. As these patients have rarely been investigated, we report on a series of patients with RMS and unknown primary tumor site registered in the Metastatic (MTS) RMS 2008 protocol (October 2008 to December 2016) coordinated by the European pediatric Soft tissue sarcoma Study Group. Patients were administered nine cycles of induction chemotherapy, and 48weeks of maintenance chemotherapy. Surgery and/or radiotherapy were planned after the first assessment of tumor response, and implemented after six cycles of chemotherapy. If feasible, radiotherapy to all sites of metastasis was recommended. We identified 10 patients with RMS and unknown primary site, most of them adolescents (median age 15.8years, range: 4.6-20.4). Nine had fusion-positive alveolar RMS. Multiple organ involvement was identified in seven patients, two only had bone marrow disease, and one only had leptomeningeal dissemination. All patients were given chemotherapy, four were irradiated, and none had surgery. Three patients underwent allogeneic bone marrow transplantation. At the time of this analysis, only two patients are alive in complete remission: one had received radiotherapy; and one had a bone marrow transplant. RMS with unknown primary tumor occurs mainly in adolescents and is typically fusion-positive alveolar. Radiotherapy may be important, but survival is poor and patients should be offered enrollment in investigational trials.

Pediatric Non-Rhabdomyosarcoma Soft Tissue Sarcomas: Standard of Care and Treatment Recommendations from the European Paediatric Soft Tissue Sarcoma Study Group (EpSSG).

This paper describes the standard of care for patients with non-rhabdomyosarcoma soft tissue sarcomas (NRSTS) and the therapeutic recommendations developed by the European paediatric Soft tissue sarcoma Study Group (EpSSG). NRSTS form a very mixed group of mesenchymal extraskeletal malignancies. Their rarity, heterogeneity, and aggressiveness make the management of children and adolescents with these tumors complex and challenging. The overall cure rate for patients with NRSTS is around 70%, but survival depends on several prognostic variables, such as histotype and tumor grade, extent of disease and stage, tumor size, and tumor site. While surgery remains the mainstay of treatment for most of these tumors, a multimodal therapeutic approach including radiotherapy and chemotherapy is required in many cases. The EpSSG NRSTS 2005 study was the first prospective protocol tailored specifically to NRSTS. Together with the ARST0332 study developed by the North-American Soft Tissue Sarcoma Committee of the Children’s Oncology Group (COG), the EpSSG NRSTS 2005 study currently represents the benchmark for these tumors, establishing risk-adapted standards of care. The EpSSG has developed common treatment recommendations for the large group of adult-type NRSTS (including synovial sarcoma), and specific treatment recommendations for other particular adult-type histologies (ie, alveolar soft-part sarcoma, clear cell sarcoma and dermatofibrosarcoma protuberans); other highly malignant tumors with a biology and clinical behavior differing from those of adult-type NRSTS (ie, rhabdoid tumors and desmoplastic small round cell tumor); and soft tissue tumors of intermediate malignancy (ie desmoid-type fibromatosis, inflammatory myofibroblastic tumors, and infantile fibrosarcoma). New effective drugs are needed for patients whose NRSTS carries the worst prognosis, ie, those with unresectable tumors, metastases at diagnosis, or relapsing disease. Progress in this area relies on our ability to develop international integrated prospective collaborations, both within existing pediatric oncology networks and, importantly, between the communities of specialists treating pediatric and adult sarcoma.

Epithelioid hemangioendothelioma in children: The European Pediatric Soft Tissue Sarcoma Study Group experience.

The European pediatric Soft tissue sarcoma Study Group analyzed all children with epithelioid hemangioendothelioma prospectively registered in the NRSTS-05 (EUDRACT 2005-001139-31) and in MTS-2008 (NCT00379457) studies: 10 patients with localized and one with metastatic disease. Median age was 14.3 years (range, 9.0-18.8). Local therapy was initial primary surgery in seven cases, and five patients received systemic therapy. No patients received radiotherapy. After a median follow-up of 50 months (range, 6-176) for living patients, nine patients remain alive off therapy and two died. Five-year progression free and overall survivals are, respectively, 77.1% (95% confidence interval [CI]: 34.5-93.9) and 74.1% (95% CI: 28.1-93.0).

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

PurposeRegional 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 methodsBetween 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). ResultsN1 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. ConclusionIn 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.