Long-term results from the multicentric European randomized phase 3 trial CWS/RMS-96 for localized high-risk soft tissue sarcoma in children, adolescents, and young adults

Multi-Targeted Kinase Inhibitor Therapy in Pediatric Bone and Soft Tissue Sarcoma Patients-A Single Centre Experience

BACKGROUND

Patients with relapsed or refractory soft tissue and bone sarcomas have dismal outcomes. Multi-targeted kinase inhibitors (mTKI) have proven to be potent agents in several malignancies, both as primer therapy and as a salvage option. Our aim was to evaluate the clinical outcomes of mTKI treatment in a heterogeneous group of pediatric sarcoma patients retrospectively.

PROCEDURES

A total of 18 patients were treated with sorafenib, regorafenib, or pazopanib; 13 of them had osteosarcoma (OSC), 3 had synovial sarcoma (SySa), and 1-1 patient had chondrosarcoma and rhabdomyosarcoma. Indication for mTKI treatment was primarily progressive, inoperable, relapsed, or chemotherapy-resistant disease after completion of first- and second-line chemotherapy.

RESULTS

At the time of the beginning of mTKI treatment, the median age was 16.5 years, and the median time to progression from initiation of mTKI was 4 months. The overall response rate was 16%. We conducted a comparison of the survival outcomes of OSC patients receiving mTKIs against a retrospective, non-randomized control group. Overall survival was evaluated from the time of progression or relapse after second-line treatment to the time of death. The log-rank test revealed a significant difference in the survival distribution between patients receiving mTKIs and those who did not (chi2(1) = 8.13 p = 0.004). We observed benefits from mTKI treatment in 3 SySa patients, with pazopanib demonstrating effectiveness and no progression observed thus far.

CONCLUSIONS

Our findings suggest that mTKIs are well-tolerated and can serve as a therapeutic option for refractory bone sarcomas as palliative treatment, aiming to slow disease progression and uphold a good quality of life.

Druggable upregulated proteins in EWS-FLI-driven Ewing sarcoma as emerging new therapeutic targets

Ewing sarcoma (ES) is a highly aggressive soft tissue tumor that primarily affects the long bones of children and young adults. It is distinguished by a characteristic chromosomal translocation between the Ewing sarcoma breakpoint region 1 (EWS) gene and the erythroblast transformation-specific (ETS) family of genes, most commonly resulting in the EWS-friend leukemia integration 1 (EWS-FLI1) fusion gene. This translocation is observed in approximately 80%-85% of ES cases. This fusion gene encodes a non-physiological chimeric fusion protein that plays a central role in tumorigenesis by interacting with numerous partner proteins. Several studies have demonstrated the tumorigenic potential of the EWS-FLI1 protein when transfected into non-cancer cell lines. However, targeting EWS-FLI1 directly remains a significant challenge, as no drug to date has been reported to bind to and inhibit its activity effectively. An alternative therapeutic strategy involves targeting key overexpressed protein complexes implicated in ES tumorigenesis, many of which may be downstream interacting partners of EWS-FLI1. This review explores emerging protein targets as potential therapeutic avenues in ES treatment.

Treatment of Pediatric, Adolescent, and Young Adult Patients With Fusion-Positive Alveolar Rhabdomyosarcoma Infiltrating Regional Lymph Nodes in the European CWS-2002P and RMS 2005 Studies and the Soft Tissue Sarcoma Registry

BACKGROUND

Patients with alveolar rhabdomyosarcoma (ARMS) with regional lymph node involvement (N1) are defined as "very-high-risk rhabdomyosarcoma" in Europe. Different chemotherapy regimens were used in European study protocols.

METHODS

Patients with FOXO1 fusion-positive N1 ARMS registered in the CWS-2002P study, the EpSSG RMS 2005 study, and SoTiSaR were retrospectively investigated. Patients received systemic treatment with chemotherapy (CHT) and local treatment of primary tumor (PT) and involved lymph nodes (LN) with radiotherapy (RT) and/or surgery. Kaplan-Meier estimators and Cox regression were used to examine event-free survival (EFS) and overall survival (OS) according to prognostic factors and treatment.

RESULTS

A total of 156 patients registered in RMS 2005 (n = 99), CWS-2002P (n = 20), and SoTiSaR (n = 37) between 2003 and 2020 were eligible for this analysis. Median age at diagnosis was 10.2 years [0.1-21.9]. Treatment comprised CHT with IVADo (ifosfamide, vincristine, actinomycin-D, doxorubicin, n = 93; 60%), VAIA (vincristine, actinomycin-D, ifosfamide, adriamycin/doxorubicin, n = 53; 34%) or other regimens (n = 10; 6%); resection of the PT (n = 89; 57%), LN sampling or dissection (n = 92; 59%), and/or RT (n = 139; 89%). Maintenance treatment (MT) was added in n = 99/135 (73%) patients who achieved complete remission. Five-year EFS and OS of the cohort were 45% and 47%, respectively. Age and tumor size were independent prognostic factors for EFS. Local treatment applied to the LN with surgery, RT or both significantly improved EFS (p = 0.02) and OS (p = 0.04), with no difference between the modalities (p = 0.7).

CONCLUSIONS

Patients with fusion-positive N1 ARMS carry a poor prognosis. Adequate local treatment of LN improved survival.

Osteosarcoma as a secondary malignancy following rhabdomyosarcoma: A report of 28 affected patients from the Cooperative Osteosarcoma Study Group (COSS)

BACKGROUND

Osteosarcoma may arise as a secondary malignancy following rhabdomyosarcoma (RMS). We utilized the Cooperative Osteosarcoma Study Group (COSS) database to better understand this association.

PATIENTS AND METHODS

The COSS database (1980-05/2023) was searched for patients whose osteosarcoma was preceded by RMS. Eligible patients were analyzed for patient-, tumor-, and treatment-related variables as well as outcomes.

RESULTS

The search revealed 28 eligible osteosarcomas (27 high-grade central, one periosteal; male:female = 16:12; median age RMS 2.1 [range: 0.9-10.0] years, osteosarcoma 13.5 [7.2-29.0] years). Genetic tumor-predisposition syndromes were documented in 12 patients. One patient had had a distinct malignancy prior to RMS, two intermittently, seven following osteosarcoma. Local RMS treatment had included radiotherapy in 20/26 cases (two unknown). Secondary osteosarcoma sites were extremity 13, trunk seven, head and neck eight; 15 osteosarcomas were radiation-associated. There was only one case of primary osteosarcoma metastases. Osteosarcoma treatment included chemotherapy (27), surgery (26), or radiotherapy (2). A macroscopically complete remission of all osteosarcoma sites was achieved in 24 cases. Median follow-up was 5.8 (range: 0.5-18.4) years after osteosarcoma and 8.1 (1.0-15.4) years for 14 survivors. Actuarial 5-year overall and event-free survival were 66% (standard error 9%) and 45% (10%), respectively. Five of 14 deaths were caused by further malignancies.

CONCLUSION

This series offers a benchmark for patients who develop a secondary osteosarcoma after RMS. Affected patients are generally still in the pediatric age. The results obtained strongly argue for genetic predisposition testing in RMS and against therapeutic leniency in comparable situations.

Maintenance therapy with trofosfamide, idarubicin and etoposide in patients with rhabdomyosarcoma and other high-risk soft tissue sarcomas (CWS-2007-HR): a multicentre, open-label, randomised controlled phase 3 trial

Background

Rhabdomyosarcoma and other soft tissue sarcomas (STS) with high-risk features are still associated with an unsatisfactory outcome. We evaluated the efficacy of oral maintenance therapy added at the end of standard therapy in patients with high-risk rhabdomyosarcoma and STS.

Methods

CWS-2007-HR was a multicentre, open-label, randomised controlled, phase 3 trial done at 87 centers in 5 countries. Eligible patients were those aged 6 months to 21 years with non-metastatic incompletely resected embryonal rhabdomyosarcoma occurring in unfavourable sites with unfavourable age (≥10 years) and/or tumour size (>5 cm); all non-metastatic alveolar rhabdomyosarcoma and those with any non-metastatic rhabdomyosarcoma with nodal involvement. A further group was also eligible: patients with non-metastatic undifferentiated sarcoma, extraskeletal Ewing sarcoma and primary unresected synovial sarcoma. Patients in complete remission at the end of standard therapy (nine cycles of ifosfamide, vincristine with doxorubicine or dactinomycin, and surgery or radiotherapy, or both) were randomised to either stop treatment (S-arm) or to receive oral maintenance therapy (M-arm) with eight 10-day courses (25 weeks) of trofosfamide (2 × 75 mg/m2/day) and idarubicin (1 × 5 mg/m2/day 1,4,7,10) alternating with trofosfamide and etoposide (2 × 25 mg/m2/day). The primary outcome was event-free survival (EFS) and the secondary outcome was overall survival (OS) in the intent-to treat population. This trial is registered at ClinicalTrials.gov, NCT00876031, and, EudraCT 2007-0001478-10.

Findings

Between July 1st, 2009 and June 30th, 2019, 195 patients were randomly assigned to the M-arm (n = 96) or S-arm (n = 99). In the intent-to-treat population, with a median follow-up of 5.2 years (IQR 3.9-6.1) for surviving patients, the 3-year EFS in the M-arm was 66.9% (95% CI 58.1-77.2) versus 75.6% (67.6-84.6) in the S-arm (hazard ratio, (HR) 1.62, 95% CI 0.98-2.69, p = 0.06). 3-year OS was 82.8% (95% CI 75.4-90.8) in the M-arm versus 84.7% (95% CI 77.8-92.1) in the S-arm (HR 1.55, 95% CI 0.84-2.89, p = 0.17). Grade 3-4 adverse events were haematological in 66% of patients, febrile infections in 6%, gastrointestinal in 10%, and sensory neuropathy in 1%.

Interpretation

The addition of 25 weeks of oral maintenance therapy with trofosfamide, etoposide and idarubicin after standard therapy does not improve EFS and OS in patients with high-risk rhabdomyosarcoma and other STS.

Funding

Deutsche Kinderkrebsstiftung Grant No.DKS 2009.09, DKS 2012.06, DKS 2015.13, DKS 2018.10 and DKS 2021.04.

Decoding pediatric spinal tumors: a single-center retrospective case series on etiology, presentation, therapeutic strategies, and outcomes

INTRODUCTION

Spinal tumors (ST) often result in dire prognosis, carrying risks such as permanent paralysis, sensory loss, and sphincter dysfunction. Data on their incidence and etiology in pediatric populations are markedly scant. Our study investigates the etiology, clinical manifestation, treatment, and outcomes of pediatric ST.

METHODS

We conducted a retrospective review of our institutional pediatric oncology and neurosurgery database, examining 14 patients under 18 years admitted with ST due to oncological diseases since 2005. We analyzed the clinical presentations, evaluations, molecular diagnostics and treatments for these patients.

RESULTS

The study spanned 15 years and included 14 pediatric patients, each diagnosed with distinct spinal tumor entity. The mean patient age was approximately 19.6 ± 10.1 months. Severe axial pain along the vertebral column was observed in 13 patients, while acute neurological deterioration manifested in 7 patients. As a first-line intervention, 13 patients underwent decompressive surgery through laminectomy and tumor resection, and only one patient received chemotherapy solely. Before surgery, seven patients were unable to walk; post-surgery, six of them regained their ability to ambulate. The diagnosis encompassed a range of neoplasms: two instances of Ewing sarcoma, 3 instances of teratoma, one case presenting an atypical teratoid Rhabdoid tumor, two instances each of low-grade astrocytoma and neuroblastoma, and single instances of ependymoma, meningioma, rhabdomyosarcoma, and embryonal tumors with multilayered rosettes (ETMRs). Three patients succumbed two years after initiating therapy.

CONCLUSION

Despite their rarity, intraspinal tumors in pediatric patients pose substantial therapeutic challenges. The intertwined complexities of the disease entity and the patient's neurological status demand swift initiation of an individualized therapeutic strategy. This crucial step helps optimize outcomes for this patient cohort, who frequently grapple with debilitating health conditions. Inclusion of these patients within a registry is mandatory to optimize treatment outcomes due to their rarity in pediatric population.

Importance of Adequate Surgical Local Control in Fusion-Negative Para-Testicular Rhabdomyosarcoma: Data From the Cooperative Weichteilsarkom Studiengruppe Trials (CWS-96 and CWS-2002P) and the European Soft Tissue Sarcoma Registry (SoTiSaR)

BACKGROUND

This study aimed to assess the impact that the quality of primary and subsequent surgeries has on the survival of patients with para-testicular rhabdomyosarcoma (PTRMS).

METHODS

Patients with localized (IRS I-III) and metastatic (IRS IV) PTRMS were enrolled in the two Cooperative Weichteilsarkom Studiengruppe (CWS) trials (CWS-96, CWS-2002P) and the Soft Tissue Sarcoma Registry (SoTiSaR).

RESULTS

Among 196 patients (median age, 8.4 years), 106 (54.1%) had primary complete resection. Image-defined lymph node (LN) disease was detected in 21 (11.5%) patients in the localized cohort and 12 (92.3%) patients in the metastatic cohort. The 5-year event-free survival (EFS) and overall survival (OS) were respectively 87.3% and 94.0% for the patients with localized PTRMS and 46.2% and 42.2% for the patients with metastatic PTRMS. Protocol violations during the primary surgery (PV-PS) were observed in 70 (42%) of the IRS I-III patients. This resulted in higher rates of R1/R2 resections (n = 53 [76%] vs n = 20 [21%]; p < 0.001) with a need for pretreatment re-excision (PRE) (n = 50 [83%] vs n = 10 [17%]; p < 0.001) compared with the patients undergoing correct primary surgery. Protocol violations during PRE occurred for 13 (20%) patients. Although PV-PS did not influence the 5-year EFS or OS in the localized PTRMS cohort, the unadjusted log-rank test showed that R status after PRE is a prognostic factor for 5-year OS (R1 vs R0 [81.8% vs 97.6%]; p = 0.02).

CONCLUSIONS

The quality of surgical local control in PTRMS is unsatisfactory. Emphasis should be placed on evaluating the resection status after PRE in further clinical trials.

What are the Optimal Systemic Treatment Options for Rhabdomyosarcoma?

OPINION STATEMENT

Rhabdomyosarcoma, a soft tissue sarcoma commonly observed in childhood, requires multidisciplinary treatment, including surgical tumor resection, chemotherapy, and radiation therapy. Although long-term survival can be expected in patients with localized rhabdomyosarcoma, the clinical outcomes in patients with metastatic or unresectable rhabdomyosarcoma remain unsatisfactory. To improve the outcomes of rhabdomyosarcoma, it is important to explore effective systemic treatments for metastatic rhabdomyosarcoma. Currently, multiagent chemotherapy comprising vincristine, actinomycin D, and ifosfamide/cyclophosphamide remains standard systemic treatment for rhabdomyosarcoma. On the other hand, new treatment, such as immune checkpoint inhibitors and molecular targeted drugs, have demonstrated superior clinical outcomes compared to those of standard treatments in various type of malignancies. Therefore, it is necessary to assess the efficacies of these treatments in patients with rhabdomyosarcoma. Recent clinical studies have shown efficacies and safeties of temozolomide combined with vincristine/irinotecan, olaratumab combined with doxorubicin or vincristine/irinotecan, and long-term maintenance therapy. Furthermore, basic researches demonstrated new therapeutic targets. Future studies using these approaches are required to assess their clinical significances.

International Consensus Statement on Allergy and Rhinology: Sinonasal Tumors

BACKGROUND

Sinonasal neoplasms, whether benign and malignant, pose a significant challenge to clinicians and represent a model area for multidisciplinary collaboration in order to optimize patient care. The International Consensus Statement on Allergy and Rhinology: Sinonasal Tumors (ICSNT) aims to summarize the best available evidence and presents 48 thematic and histopathology-based topics spanning the field.

METHODS

In accordance with prior International Consensus Statement on Allergy and Rhinology documents, ICSNT assigned each topic as an Evidence-Based Review with Recommendations, Evidence-Based Review, and Literature Review based on the level of evidence. An international group of multidisciplinary author teams were assembled for the topic reviews using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses format, and completed sections underwent a thorough and iterative consensus-building process. The final document underwent rigorous synthesis and review prior to publication.

RESULTS

The ICSNT document consists of four major sections: general principles, benign neoplasms and lesions, malignant neoplasms, and quality of life and surveillance. It covers 48 conceptual and/or histopathology-based topics relevant to sinonasal neoplasms and masses. Topics with a high level of evidence provided specific recommendations, while other areas summarized the current state of evidence. A final section highlights research opportunities and future directions, contributing to advancing knowledge and community intervention.

CONCLUSION

As an embodiment of the multidisciplinary and collaborative model of care in sinonasal neoplasms and masses, ICSNT was designed as a comprehensive, international, and multidisciplinary collaborative endeavor. Its primary objective is to summarize the existing evidence in the field of sinonasal neoplasms and masses.

Radiotherapy and long-term sequelae in pediatric patients with parameningeal rhabdomyosarcoma: Results of two Cooperative Weichteilsarkom Studiengruppe (CWS) trials and one registry

BACKGROUND

Parameningeal location of rhabdomyosarcoma (PM RMS) is known to be an unfavorable prognostic factor. Scarce data are available on radiotherapy (RT) concepts with regard to outcome.

METHODS

Treatment and outcome of 395 children with PM RMS registered within two Cooperative Weichteilsarkom Studiengruppe (CWS) trials and one registry (1995-2021) were evaluated.

RESULTS

Patients were IRS group II (n = 15) and III (n = 380) and received systemic treatment according to the enrolled protocols: I2VA (n = 172), VAIA/CEVAIE (n = 223). Delayed resection was performed in 88/395 (22%) patients, and RT was additionally given in 79/88 (90%) resected patients. RT was the predominant local treatment in 355/395 (90%) patients: hyperfractionated accelerated photon (HART; n = 77), conventionally fractionated photon (n = 91) or proton beam (n = 126), brachytherapy (n = 4), heavy ions (n = 1), not available (n = 56). In the subgroup of RT as only local treatment (n = 278), no intracranial tumor extension and complete remission at end of treatment were significant positive prognostic factors. No significant difference on tumor outcome was seen between different radiotherapy concepts. Long-term toxicity with mostly endocrinological and visual deficiencies was reported in 161/279 (58%) surviving patients with a lower trend after proton beam RT (48%) when compared to HART or conventionally fractionated photon RT (71% and 72%, respectively). Ten-year event-free and overall survival in the overall group were 62% (±5, 95% confidence interval [CI]) and 67% (±5, 95% CI); in the RT-only group 67% (±6, 95% CI) and 71% (±6, 95% CI), respectively.

CONCLUSION

CWS data confirm the recent RT concept in PM RMS. Long-term sequelae as endocrinological and visual deficiencies need to be addressed.

Significance of fusion status, Oberlin risk factors, local and maintenance treatment in pediatric and adolescent patients with metastatic rhabdomyosarcoma: Data of the European Soft Tissue Sarcoma Registry SoTiSaR

BACKGROUND

Outcome of primary metastatic rhabdomyosarcoma (RMS) is poor. Certain risk factors as fusion status, Oberlin score, and local treatment of primary tumor are known to influence prognosis.

PROCEDURE

Patients with metastatic RMS were treated according to Cooperative Weichteilsarkom Studiengruppe (CWS) guidance with chemotherapy (CHT), radiotherapy (RT) excluding total lung irradiation (TLI), complete resection of the primary tumor, and metastasectomy if possible. Kaplan-Meier estimators and Cox proportional hazard models were used to examine event-free survival (EFS) and overall survival (OS) involving also landmark analyses.

RESULTS

In the European Soft Tissue Sarcoma Registry SoTiSaR (2009-2018), 211 patients were analyzed. Many patients had fusion-positive alveolar RMS (n = 83; 39%). Median age was 9.4 years [0.1-19.7 years]. Treatment primarily consisted of CHT with CEVAIE (carboplatin, epirubicine, vincristine, actinomycin-D, ifosfamide, etoposide: 86%, other regimens: 14%), RT (71%), resection of primary tumor (37%), metastasectomy (19%), and lymph node sampling/dissection (21%). Maintenance treatment (MT) (oral trofosfamide, idarubicin, etoposide) was added in 74% of patients. Oberlin factors, fusion status, and MT were predictive for EFS and OS. MT with O-TIE was not improving outcome when adjusting for the immortal time bias. Local treatment of the primary tumor and radical irradiation (except TLI) improved EFS, not OS, when adjusting for the Oberlin score. Patients with fusion-negative alveolar RMS (n = 9) had an excellent outcome with a 5-year EFS and OS of 100%, compared to patients with embryonal RMS (49%/62%), PAX7- (22%/47%) and PAX3/FOXO1-positive ARMS (10/13%), respectively (p < .001).

CONCLUSIONS

Prognosis of metastatic RMS primarily depends on fusion status and Oberlin score. Fusion status needs to be considered in future trials to optimize treatment outcome. The role of radical irradiation needs further investigation.

Progression and Relapse of Pediatric Soft Tissue Sarcoma: Individualized Approach of Treatment - Experience from a Major Pediatric Cancer Center in Europe

BACKGROUND

The outcome of children with refractory or relapsed soft tissue sarcoma (STS) is extremely poor. Whereas larger clinical trials evaluated specific treatment modalities, real-life data on individual multimodal therapeutic strategies, given alone or in combination, are scarce.

PATIENTS AND METHODS

We retrospectively analyzed the clinical course of 18 pediatric patients with progression of or relapsed STS treated between 2008 and 2018 in our institution.

RESULTS

A total of 18 patients (median age 12.4 years) suffered from progression or relapse of alveolar (n=7), embryonal (n=5), undifferentiated (n=2) rhabdomyosarcoma or desmoplastic small round cell tumor (n=4). 14 patents had an initial stage IV disease. All but one patient died. Median survival was 12.5 months. Shortest survival was seen in patients with systemic progression of the disease, longest in patients with local relapse. Patients with an Oberlin score<2 at the time of relapse had a significant longer time of survival than those with a score≥2. No significant advantage of a specific therapeutic modality was observed.

DISCUSSION

We critically analyzed the clinical course in the real-life setting, in which various treatment options were applied to an individual patient according to the best of available data. We observed that some patients died within a short period of time despite multiple treatment modalities, which underlines the need for better prognostic parameters.

CONCLUSION

In addition to well characterized clinical factors such as local or systemic relapse, the Oberlin score could be helpful in counselling patients and their families for choosing the best strategy of care.

Which Patients With Rhabdomyosarcoma Need Radiotherapy? Analysis of the Radiotherapy Strategies of the CWS-96 and CWS-2002P Studies and SoTiSaR Registry

PURPOSE

To analyze and compare the indications, doses, and application methods of radiotherapy (RT) and their influence on prognosis of patients with localized rhabdomyosarcoma (RMS).

METHODS

One thousand four hundred seventy patients with localized RMS 21 years and younger entered on CWS-96, CWS-2002P, and SoTiSaR were eligible for the analysis. The median follow-up was 6.5 years (IQR, 3.3-9.5).

RESULTS

The 5-year event-free survival (EFS) and local control survival (LCS) for 910 (62%) irradiated versus nonirradiated patients were 71% versus 69% and 78% versus 73% (P = .03), respectively. Ninety-five percent of patients in IRS I (90% embryonal RMS [eRMS]) were nonirradiated (EFS, 87%). Irradiated patients with IRS II had improved LCS (91% v 80%; P = .01) and EFS (not significant). In IRS III, EFS and LCS were significantly better for RT patients: 71% versus 56% (P = 3.1e-06) and 76% versus 61% (P = 4.1e-07). Patients with tumors in the head and neck region (orbita, parameningeal, and nonparameningeal) and in other sites had significantly better EFS and LCS and in parameningeal also overall survival (OS). The efficacy of low RT doses of 32 Gy (hyperfractionated, accelerated RT [HART]) and 36 and 41.4 Gy (conventional fractionated RT [CFRT]) in the favorable groups and higher doses of 44.8 Gy (HART) and 50.4 and 55.4 Gy (CFRT) in the unfavorable groups was comparable. Proton RT was used predominantly in head/neck-parameningeal (HN-PM) tumors, with similar EFS and LCS to photon RT.

CONCLUSION

RT can be omitted in patients with IRS I eRMS. RT improves LCS and EFS in IRS II and III. RT improves OS in patients with HN-PM, with proton RT comparable with photon RT. Doses of 32 Gy (HART) or 36 and 41.4 Gy (CFRT) had comparable efficacy in patients with favorable risk profiles and 44.8 Gy (HART) or 50.4 and 55.8 Gy (CFRT) in the unfavorable groups.

Clinical Insight on Proton Therapy for Paediatric Rhabdomyosarcoma

This paper offers an insight into the use of Proton Beam Therapy (PBT) in paediatric patients with rhabdomyosarcoma (RMS). This paper provides a comprehensive analysis of the literature, investigating comparative photon-proton dosimetry, outcome, and toxicity. In the complex and multimodal scenario of the treatment of RMS, clear evidence of the therapeutic superiority of PBT compared to other modern photon techniques has not yet been demonstrated; however, PBT can be considered an excellent treatment option, in particular for young children and patients with specific primary sites, such as the head and neck area (and especially the parameningeal regions), genito-urinary, pelvic, and paravertebral regions. The unique depth-dose characteristics of protons can be exploited to achieve significant reductions in normal tissue doses and may allow an escalation of tumour doses and greater sparing of normal tissues, thus potentially improving local control while at the same time reducing toxicity and improving quality of life. However, access of children with RMS (and more in general with solid tumors) to PBT remains a challenge, due to the limited number of available proton therapy installations.

Ewing Sarcoma Drug Therapy: Current Standard of Care and Emerging Agents

Ewing sarcoma is a translocation-associated sarcoma mainly impacting adolescents and young adults. The classic translocation (EWSR1::FLI1) leads to a fusion oncoprotein that functions as an aberrant transcription factor. As such, the oncogenic driver of this disease has been difficult to target pharmacologically and, therefore, the systemic therapies used to treat patients with Ewing sarcoma have typically been non-selective cytotoxic chemotherapy agents. The current review highlights recent clinical trials from the last decade that provide the evidence base for contemporary drug therapy for patients with Ewing sarcoma, while also highlighting novel therapies under active clinical investigation in this disease. We review recent trials that have led to the establishment of interval-compressed chemotherapy as an international standard for patients with newly diagnosed localized disease. We further highlight recent trials that have shown a lack of demonstrable benefit from high-dose chemotherapy or IGF-1R inhibition for patients with newly diagnosed metastatic disease. Finally, we provide an overview of chemotherapy regimens and targeted therapies used in the management of patients with recurrent Ewing sarcoma.

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.