Abstract

Ewing sarcoma, a highly aggressive bone and soft-tissue cancer, is considered a prime example of the paradigms of a translocation-positive sarcoma: a genetically rather simple disease with a specific and neomorphic-potential therapeutic target, whose oncogenic role was irrefutably defined decades ago. This is a disease that by definition has micrometastatic disease at diagnosis and a dismal prognosis for patients with macrometastatic or recurrent disease. International collaborations have defined the current standard of care in prospective studies, delivering multiple cycles of systemic therapy combined with local treatment; both are associated with significant morbidity that may result in strong psychological and physical burden for survivors. Nevertheless, the combination of non-directed chemotherapeutics and ever-evolving local modalities nowadays achieve a realistic chance of cure for the majority of patients with Ewing sarcoma. In this review, we focus on the current standard of diagnosis and treatment while attempting to answer some of the most pressing questions in clinical practice. In addition, this review provides scientific answers to clinical phenomena and occasionally defines the resulting translational studies needed to overcome the hurdle of treatment-associated morbidities and, most importantly, non-survival.

Highlights

  • Ewing sarcoma (EwS) represents a rare, highly malignant cancer, with most patients harboring a priori micrometastases [1,2], since, without systemic therapy, over 90% of patients die from disseminated disease [3]

  • Apart from the above-mentioned ELS, there is an increasing number of very rare ELS with translocations such as Ewing sarcoma breakpoint region 1 gene (EWSR1)-SMARCA5, EWSR1-SP3, and EWSR1-PATZ1 [95,96,97], which do not cluster in unsupervised transcriptome analyses with EwS [84]. Clinicopathological data on these tumors are scarce, analyses of recent case series suggest that EWSR1-PATZ1 gene fusions may define a glioneuronal tumor entity [98], which appears to occur across a wide age range and which may show a predilection for the chest wall [95]

  • Recent publications displayed that combined surgical resection and RT are associated with a higher overall survival probability in non-sacral tumors compared with surgery alone, even in patients with a wide resection and a good histologic response to neoadjuvant chemotherapy [127,128]; in contrast, different data questioned the need for additional RT in extremity EwS because of low percentages of local recurrence in extremity tumors and associated toxicity [129]

Read more

Summary

Introduction

Ewing sarcoma (EwS) represents a rare, highly malignant cancer, with most patients harboring a priori micrometastases [1,2], since, without systemic therapy, over 90% of patients die from disseminated disease [3]. Many aspects of the disease require further study, e.g., cryptic cell of origin, phenomenon of oncogene addiction as well as oncogene plasticity, distinct molecular activities and clinical relevance of fusion proteins in EwS, CIC-rearranged sarcoma, sarcoma with BCOR genetic alterations, and round cell sarcoma with EWSR1-non-ETS fusions EwS-related entities may differ radiologically from classical EwS, e.g., small round cell sarcomas (SRCS) with CIC-DUX4 fusion often present as necrotic and hypermetabolic soft-tissue masses while SRCS with BCOR-CCNB3 translocations are vascular bone lesions with necrosis at imaging (please see section “Round cell sarcoma with non-ETS-fusions and CIC/BCOR-rearranged sarcoma”) [27]

Local Tumor Assessment and Staging—“Trust in T1”
Therapeutic Assessment and Follow-Up
The Risk of Tumor Seeding along the Access Path of Biopsy
Biopsy—The Holy Tissue Grail
Historical Evolution of EwS and EwS-Related Entities
Surgical Strategies—Both Form and Function Follow Local Control
Initial Versus Chemotherapy Responsive Tumor—Operate to What Extent?
Pathological Fracture in EwS
EwS of the Extremities and the Role of Limb Perfusion
Pelvic and Sacral EwS—When and How to Operate?
Primary Thoracic EwS
3.1.10. Disseminated and Relapsed EwS
Modern RT Strategies and Techniques
Radiation Toxicity with High-Dose Treatment
Irradiation for Palliation
Addition of Ifosfamide and Etoposide Further Improves Outcomes
Intensified Therapies—Time but Not Dose or Duration Matters
Key Findings
Approach Relapse Therapy
Maintenance Therapy in EwS
Adding Targeted Therapies to Existing Backbone Regimens
Established and Emerging Targeted Therapies for Relapsed Disease
Where Is Targeted Therapy Heading?
Challenges to Treat EwS in Low- and Middle-Income Countries
Immunotargeting of EwS Tumors
Biological Concepts for Organotropism of EwS Metastasis
Non-Patient Derived EwS Models
Biomarkers
Conclusion
Findings
Limitations and Future Perspectives for EwS Biomarkers
Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.