Developments in the Surgical Approach to Staging and Resection of Rhabdomyosarcoma.

Although survival after rhabdosarcoma treatment has improved over the years, one third of patients still develop locoregional relapse. This review aims to highlight developments pertaining to staging and local treatment of specific RMS tumor sites, including head and neck, chest/trunk, bladder-prostate, female genito-urinary, perianal, and extremity sites.

QUARTET: A SIOP Europe project for quality and excellence in radiotherapy and imaging for children and adolescents with cancer.

The European Society for Paediatric Oncology (SIOPE) Radiation Oncology Working Group presents the QUARTET Project: a centralised quality assurance programme designed to standardise care and improve the quality of radiotherapy and imaging for international clinical trials recruiting children and adolescents with cancer throughout Europe. QUARTET combines the paediatric radiation oncology expertise of SIOPE with the infrastructure and experience of the European Organisation for Research and Treatment of Cancer to deliver radiotherapy quality assurance programmes for large, prospective, international clinical trials. QUARTET-affiliated trials include children and adolescents with brain tumours, neuroblastoma, sarcomas including rhabdomyosarcoma, and renal tumours including Wilms' tumour. With nine prospective clinical trials and two retrospective studies within the active portfolio in March 2022, QUARTET will collect one of the largest repositories of paediatric radiotherapy and imaging data, support the clinical assessment of radiotherapy, and evaluate the role and benefit of radiotherapy quality assurance for this cohort of patients within the context of clinical trials.

What Do We Know about Survival in Skeletally Premature Children Aged 0 to 10 Years with Ewing Sarcoma? A Multicenter 10-Year Follow-Up Study in 60 Patients.

(1) Background: Younger age has been associated with better overall survival (OS) in Ewing sarcoma (ES), especially under the age of 10. The favorable survival in younger patients underlines the need for minimizing treatment burden and late sequelae. Our study aimed at describing clinical characteristics, treatment and outcome of a cohort of ES patients aged 0−10. (2) Methods: In this retrospective multicenter study, all consecutive ES patients aged 0−10, treated in four sarcoma centers in the Netherlands (n = 33) and one in Spain (n = 27) between 1982 and 2008, with a minimum follow-up of 10 years, were included. OS, local recurrence-free survival (LRFS) and distant metastasis-free survival (DMFS) were calculated. Potential factors of influence on OS (risk and protective factors) were analyzed. (3) Results: 60 patients with median follow-up 13.03 years were included. All patients were treated with chemotherapy in combination with local treatment, being surgery alone in 30 (50%) patients, radiotherapy (RT) alone in 12 (20%) patients or surgery plus RT in 18 (30%) patients (12 pre- and 6 postoperative). Limb salvage was achieved in 93% of patients. The 10-OS, -LRFS and -DMFS are 81% (95% CI: 71−91%), 89% (95% CI: 85−93%) and 81% (95% CI: 71−91%), respectively. Six patients developed LR, of which two developed subsequent DM; all had axial ES (pelvis, spine or chest wall), and these patients all died. Ten patients developed DM; eight died due to progressive disease, and two are currently in remission, both with pulmonary metastasis only. Negative or wide resection margin was significantly associated with better OS. Age < 6 years, tumor volume < 200 mL, absence of metastatic disease and treatment after 2000 showed trends towards better OS. Two patients developed secondary malignancy; both had chemotherapy combined with definitive RT for local treatment. (4) Conclusions: Overall survival of these youngest patients with ES was very good. Limb salvage surgery was achieved in >90% of patients. Wide resection margin was the only factor significantly associated with better survival.

Loss of H3K27me3 occurs in a large subset of embryonal rhabdomyosarcomas: Immunohistochemical and molecular analysis of 25 cases.

Loss of histone 3 lysine 27 trimethylation (H3K27me3) has been described as a diagnostic marker for malignant peripheral nerve sheath tumor (MPNST), also discriminating MPNST with rhabdomyoblastic differentiation (malignant Triton tumor) from rhabdomyosarcoma (RMS). We studied the immunohistochemical expression of H3K27me3 in embryonal RMSs (ERMSs), performed methylation profiling in order to support the diagnosis and RNA-sequencing for comparison of the transcriptome of H3K27me3-positive and -negative cases. Of the 25 ERMS patients, 17 were males and 8 were females with an age range from 1 to 67 years (median, 6 years). None were known with neurofibromatosis type 1. One patient had Li-Fraumeni syndrome. Tumor localization included paratesticular (n = 9), genitourinary (n = 6), head/neck (n = 5), retroperitoneal (n = 4) and lower arm (n = 1). Five MPNSTs served as reference group. All ERMS had classical features including a variable spindle cell component. Immunohistochemical loss (partial or complete) of H3K27me3 was detected in 18/25 cases (72%). Based on methylation profiling, 22/22 cases were classified as ERMS. Using RNA sequencing, the ERMS group (n = 14) had a distinct gene expression profile in contrast to MPNSTs, confirming that the H3K27me3 negative ERMS cases do not represent malignant Triton tumors. When comparing H3K27me3-negative and -positive ERMSs, gene set enrichment analysis revealed differential expression of genes related to histone acetylation and normal muscle function with H3K27me3 negative ERMSs being associated with acetylation. Conclusion: Loss of H3K27me3 frequently occurs in ERMSs and correlates with H3K27 acetylation. H3K27me3 is not a suitable marker to differentiate ERMS (with spindle cell features) from malignant Triton tumor.

Embryonal rhabdomyosarcoma completely resected at diagnosis: The European paediatric Soft tissue sarcoma Study Group RMS2005 experience.

BACKGROUND: Rhabdomyosarcoma (RMS) is the most common form of soft tissue sarcoma in children. We report the results of the European paediatric Soft tissue sarcoma Study Group (EpSSG) RMS 2005 study, which prospectively evaluated the reduction of chemotherapy in patients with embryonal RMS (ERMS) after initial surgery. METHODS: Between October 2005 and December 2016, all patients with localised ERMS with an initial microscopically complete resection (IRS group I) with lymph node-negative (N0) were prospectively enrolled in the low-risk (n = 70, subgroup A; age < 10 years and tumour size ≤ 5 cm) or standard-risk group (n = 108, subgroup B; age ≥ 10 years or tumour size > 5 cm. Subgroup A received 8 courses of vincristine and dactinomycin (VA) for 22 weeks; subgroup B received 4 courses of VA with ifosfamide (IVA) and 5 courses of VA for 25 weeks. RESULTS: The 5-year event-free survival (EFS) and overall survival (OS) were 90.8% (95% confidence interval [CI]: 85.0-94.4) and 95.7% (95% CI: 90.5-98.1), respectively (n = 178). The EFS and OS were 95.5% (95% CI: 86.8-98.5) and 100% (subgroupA), and 87.8% (95% CI: 79.3-93.0) and 93.0% (95% CI: 84.8-96.8)(subgroup B), respectively. Bearman stage 2 veno-occlusive disease (VOD) occurred in 4 very young patients. CONCLUSION: VA treatment for 8 courses was effective and well tolerated by the subgroup of patients with low-risk ERMS (group A). Four courses of IVA and 5 courses of VA instead of 9 courses of IVA also has very good results. Careful monitoring for liver toxicity is important in very young patients. European union drug regulating authorities clinical trials EUDRACT No. 2005-000217-35.

Phenotypic profiling with a living biobank of primary rhabdomyosarcoma unravels disease heterogeneity and AKT sensitivity.

Cancer therapy is currently shifting from broadly used cytotoxic drugs to patient-specific precision therapies. Druggable driver oncogenes, identified by molecular analyses, are present in only a subset of patients. Functional profiling of primary tumor cells could circumvent these limitations, but suitable platforms are unavailable for most cancer entities. Here, we describe an in vitro drug profiling platform for rhabdomyosarcoma (RMS), using a living biobank composed of twenty RMS patient-derived xenografts (PDX) for high-throughput drug testing. Optimized in vitro conditions preserve phenotypic and molecular characteristics of primary PDX cells and are compatible with propagation of cells directly isolated from patient tumors. Besides a heterogeneous spectrum of responses of largely patient-specific vulnerabilities, profiling with a large drug library reveals a strong sensitivity towards AKT inhibitors in a subgroup of RMS. Overall, our study highlights the feasibility of in vitro drug profiling of primary RMS for patient-specific treatment selection in a co-clinical setting.

Local staging and treatment in extremity rhabdomyosarcoma. A report from the EpSSG-RMS2005 study.

Rhabdomyosarcoma of the extremities present with two main challenges: correct evaluation of initial regional nodal involvement and define adequate local treatment. METHODS: Pediatric patients with localized rhabdomyosarcoma of the extremity included in the EpSSG-RMS2005 study between 2005 and 2014 were evaluated for staging, treatment, and survival. The outcome was compared to the preceding European SIOP-MMT studies. RESULTS: Of the 162 patients included, histology was unfavorable in 113 (70%), 124 (77%) were younger than 10 years, 128 (79%) were IRS III, and 47 (29%) were node-positive. A regional node biopsy was performed in 97 patients (60%) and modified the lymph node stage in 15/97 (16%). Primary and delayed surgery was performed in 155 (96%) and radiotherapy delivered in 118 (73%) patients. Relapse occurred in 61 cases (38%), local in 14 (23%), regional in 13 (21%), distant in 22 (36%), and combined relapse in 12 (20%) with five progressive diseases (8%) and four secondary tumors (7%). Five-year event free (EFS) and overall survival (OS) were 58.4% (95%CI, 50.3-65.7) and 71.7% (63.6-78.4), respectively. In the previous studies MMT89 and MMT95, tumor surgery was performed in 32/53 (60%) and 74/82(90%), respectively, and radiotherapy delivered in 13/53 (25%) and 26/82 (30%), respectively. Five-year EFS and OS were 35.6%, and 50.3% in MMT89 and 54.3% and 68.2% in the MMT95 study. CONCLUSIONS: Even if the lymph node staging was not always complete according to the RMS2005 protocol, node sampling changed lymph node status in a significant number of patients. Despite the higher rate of patients treated with locoregional radiotherapy, survival in RMS2005 did not improve compared to the previous European SIOP-MMT95 study.

An overview of radiological manifestations of acquired dental developmental disturbances in paediatric head and neck cancer survivors.

OBJECTIVES: In paediatric cancer survivors treated with chemotherapy and radiotherapy therapy, late effects on dental development are quite common. Oral radiologists are not familiar with the radiographic images of these specific dental consequences of chemotherapy and radiotherapy. With the goal of educating colleagues, to raise awareness of the needs of survivors, and to identify directions for future research, we present dental radiographs of survivors treated for head and neck rhabdomyosarcoma with chemotherapy and radiotherapy. Also, based on the survivors reviewed, a radiographic inventory of commonly found late dental developmental effects seen in conjunction with treatment is presented. METHODS: Panoramic radiographic findings of five illustrative cases are presented, from a group of 42 survivors of head and neck rhabdomyosarcoma treated at the Academic Medical Center Amsterdam, The Netherlands over the past 25 years. RESULTS: Five cases showing dental developmental disorders are presented. These cases show an association of the location of the radiation field and the developmental stage of the teeth with the severity of the effect on dental development. We also report an inventory of severe and moderate effects of chemotherapy and radiotherapy on the development of molars and anterior teeth. CONCLUSIONS: This paper presents five cases and a radiographic inventory to illustrate disturbances of dental development associated with chemotherapy and radiotherapy in children. Medical and dental professionals involved in the treatment of cancer survivors are relatively unaware of the dental consequences of radiation therapy and the age dependency of specific regional effects. These effects can be severe, with great impact on quality of life. Further research in this area could help improve planning of radiation therapy for children, potentially preventing or limiting dental or maxillofacial sequelae.

Expression and clinical association of programmed cell death-1, programmed death-ligand-1 and CD8+ lymphocytes in primary sarcomas is subtype dependent.

In order to explore the potential of immune checkpoint blockade in sarcoma, we investigated expression and clinical relevance of programmed cell death-1 (PD-1), programmed death ligand-1 (PD-L1) and CD8 in tumors of 208 sarcoma patients. Primary untreated osteosarcoma (n = 46), Ewing sarcoma (n = 32), alveolar rhabdomyosarcoma (n = 20), embryonal rhabdomyosarcoma (n = 77), synovial sarcoma (n = 22) and desmoplastic small round cell tumors (DSRCT) (n = 11) were examined immunohistochemically. PD-L1 expression was predominantly detected in alveolar and embryonal rhabdomyosarcomas (15% and 16%, respectively). In the alveolar subtype PD-L1 expression was associated with better overall, event-free and metastases-free survival. PD-1 expression on lymphocytes was predominantly seen in synovial sarcomas (18%). High levels of CD8+ lymphocytes were predominantly detected in osteosarcomas (35%) and associated with worse event-free survival in synovial sarcomas. Ewing sarcoma and DSRCTs showed PD-1 on tumor cells instead of on tumor infiltrating lymphocytes. Overall, expression and clinical associations were found to be subtype dependent. For the first time PD-1 expression on Ewing sarcoma (19%) and DSRCT (82%) tumor cells was described.