Systemic therapy for osteosarcoma and Ewing sarcoma

The Role of Ubiquitination in Osteosarcoma Development and Therapies

The ubiquitin-proteasome system (UPS) maintains intracellular protein homeostasis and cellular function by regulating various biological processes. Ubiquitination, a common post-translational modification, plays a crucial role in the regulation of protein degradation, signal transduction, and other physiological and pathological processes, and is involved in the pathogenesis of various cancers, including osteosarcoma. Osteosarcoma, the most common primary malignant bone tumor, is characterized by high metastatic potential and poor prognosis. It is a refractory bone disease, and the main treatment modalities are surgery combined with chemotherapy. Increasing evidence suggests a close association between UPS abnormalities and the progression of osteosarcoma. Due to the complexity and pleiotropy of the ubiquitination system, each step in the ubiquitination process can be targeted by drugs. In recent years, research and development of inhibitors targeting the ubiquitin system have increased gradually, showing great potential for clinical application. This article reviews the role of the ubiquitination system in the development and treatment of osteosarcoma, as well as research progress, with the hope of improving the therapeutic effects and prognosis of osteosarcoma patients by targeting effective molecules in the ubiquitination system.

Correlation of High-Grade Osteosarcoma Response to Chemotherapy with Enhanced Tissue Immunological Response: Analysis of CD95R, IFN-γ, Catalase, Hsp70, and VEGF

High-grade osteosarcoma, a primary malignant bone tumour, is experiencing a global increase in reported incidence with varied prevalence. Despite advances in management, which include surgery and neoadjuvant chemotherapy often an unsatisfactory outcome is found due to poor or heterogeneous response to chemotherapy. Our study delved into chemotherapy responses in osteosarcoma patients and associated molecular expressions, focusing on CD95 receptor (CD95R), interferon (IFN)-γ, catalase, heat-shock protein (Hsp)70, and vascular endothelial growth factor (VEGF). Employing immunohistochemistry and Huvos grading of post-chemo specimens, we analysed formalin-fixed paraffin-embedded (FFPE) osteosarcoma tissue of resected post-chemotherapy specimens from Dr. Soetomo General Academic Hospital in Surabaya, Indonesia (DSGAH), spanning from 2016 to 2020. Results revealed varied responses (poor 40.38%, moderate 48.08%, good 11.54%) and distinct patterns in CD95R, IFN-γ, catalase, Hsp70, and VEGF expression. Significant differences among response groups were observed in CD95R and IFN-γ expression in tumour-infiltrating lymphocytes. The trend of diminishing CD95R expression from poor to good responses, accompanied by an increase in IFN-γ, implied a reduction in the count of viable osteosarcoma cells with the progression of Huvos grading. Catalase expression in osteosarcoma cells was consistently elevated in the poor response group, while Hsp70 expression was highest. VEGF expression in macrophages was significantly higher in the good response group. In conclusion, this study enhances our understanding of immune-chemotherapy interactions in osteosarcoma and identifies potential biomarkers for targeted interventions.

Current approaches in tissue engineering-based nanotherapeutics for osteosarcoma treatment

Osteosarcoma (OS) is a malignant bone neoplasm plagued by poor prognosis. Major treatment strategies include chemotherapy, radiotherapy, and surgery. Chemotherapy to treat OS has severe adverse effects due to systemic toxicity to healthy cells. A possible way to overcome the limitation is to utilize nanotechnology. Nanotherapeutics is an emerging approach in treating OS using nanoparticulate drug delivery systems. Surgical resection of OS leaves a critical bone defect requiring medical intervention. Recently, tissue engineered scaffolds have been reported to provide physical support to bone defects and aid multimodal treatment of OS. These scaffolds loaded with nanoparticulate delivery systems could also actively repress tumor growth and aid new bone formation. The rapid developments in nanotherapeutics and bone tissue engineering have paved the way for improved treatment efficacy for OS-related bone defects. This review focuses on current bifunctional nanomaterials-based tissue engineered (NTE) scaffolds that use novel approaches such as magnetic hyperthermia, photodynamic therapy, photothermal therapy, bioceramic and polymeric nanotherapeutics against OS. With further optimization and screening, NTE scaffolds could meet clinical applications for treating OS patients.

Surgical Treatments and Long-Term Outcomes for Pediatric Patients With Lumbar Spinal Tumors

STUDY DESIGN

Retrospective case‒control study.

OBJECTIVES

This study aimed to report the effects of surgical intervention on spinal stability recovery and to assess the long-term outcomes of children and adolescents with lumbar tumors.

METHODS

From January 2016 to June 2021, 42 pediatric patients with lumbar tumors were selected and separated into different groups based on the surgical method used (total en bloc resection (TER) group, n = 21; piecemeal resection (PR) group, n = 21; titanium mesh (TM) group n = 23; artificial vertebrae (AV) group n = 19). The clinicopathological characteristics, treatments and related outcomes were described in detail and compared between groups, with P value ≤.05 indicating statistically significant differences.

RESULTS

The average follow-up duration was 24.89 months, and the mean age was 14.89 ± 2.41 years. There were no significant differences in the mean operation time, average blood loss, complication rate, or length of hospital stay between the groups. The ODI, VAS and JOA scores at the final follow-up (FF) were elevated after surgery in all groups. The FF local angular drift (LOD) and lumbar angular drift (LUD) were greater in the TM group than in the AV group (P = .03, P = .001).

CONCLUSIONS

After surgery, pediatric patients with lumbar tumors can obtain satisfactory spinal stability, effective relief of pain symptoms and substantial improvements in neurological function. There was no significant difference in the invasiveness, safety or timeliness between the 2 surgical methods, so TER is recommended due to its low postoperative recurrence rate and good local control. Spinal fusion in the AV group resulted in better spinal stability.

Targeting transforming growth factor beta signaling in metastatic osteosarcoma

Osteosarcoma is a rare type of bone cancer, and half of the cases affect children and adolescents younger than 20 years of age. Despite intensive efforts to improve both chemotherapeutics and surgical management, the clinical outcome for metastatic osteosarcoma remains poor. Transforming growth factor β (TGF-β) is one of the most abundant growth factors in bones. The TGF-β signaling pathway has complex and contradictory roles in the pathogenesis of human cancers. TGF-β is primarily a tumor suppressor that inhibits proliferation and induces apoptosis of premalignant epithelial cells. In the later stages of cancer progression, however, TGF-β functions as a metastasis promoter by promoting tumor growth, inducing epithelial-mesenchymal transition (EMT), blocking antitumor immune responses, increasing tumor-associated fibrosis, and enhancing angiogenesis. In contrast with the dual effects of TGF-β on carcinoma (epithelial origin) progression, TGF-β seems to mainly have a pro-tumoral effect on sarcomas including osteosarcoma (mesenchymal origin). Many drugs that target TGF-β signaling have been developed: neutralizing antibodies that prevent TGF-β binding to receptor complexes; ligand trap employing recombinant Fc-fusion proteins containing the soluble ectodomain of either type II (TβRII) or the type III receptor ((TβRIII), preventing TGF-β from binding to its receptors; antisense nucleotides that reduce TGF-β expression at the transcriptional/translational level; small molecule inhibitors of serine/threonine kinases of the type I receptor (TβRI) preventing downstream signaling; and vaccines that contain cell lines transfected with TβRII antisense genes, or target furin convertase, resulting in reduced TGF-β signaling. TGF-β antagonists have been shown to have effects on osteosarcoma in vitro and in vivo. One of the small molecule TβRI inhibitors, Vactosertib, is currently undergoing a phase 1/2 clinical trial to evaluate its effect on osteosarcoma. Several phase 1/2/3 clinical trials have shown TGF-β antagonists are safe and well tolerated. For instance, Luspatercept, a TGF-β ligand trap, has been approved by the FDA for the treatment of anemia associated with myeloid dysplastic syndrome (MDS) with ring sideroblasts/mutated SF3B1 with acceptable safety. Clinical trials evaluating the long-term safety of Luspatercept are in process.

The effectiveness and mechanical properties of chemotherapy-impregnated cement in Ewing sarcoma

Bone cement is often used in the surgical treatment of Ewing sarcoma (ES). Chemotherapy-impregnated cement (CIC) has never been tested in slowing ES growth. The purpose of the study is to determine if CIC can decrease cell proliferation, and to assess changes in the mechanical qualities of the cement. Chemotherapeutic agents including doxorubicin, cisplatin, etoposide, and SF2523 were mixed with bone cement. ES cells were plated and exposed to cell growth media that had contained CIC or regular bone cement (RBC) as a control, and cell proliferation assays were performed daily for 3 days. Mechanical testing on RBC and CIC was also performed. There was a significant decrease (p < 0.001) in cell proliferation among all cells treated with CIC compared to cells treated with RBC by 48 h postexposure. Additionally, there was a synergistic effectiveness of the CIC noted when multiple antineoplastic agents were combined. Three-point bending tests did not reveal substantial reductions in tolerated maximum bending load and maximal displacement at maximal bending load between CIC and RBC. Statement of Clinical Significance: CIC does appear to be effective at decreasing cell growth and does not appear to substantially alter the mechanical properties of the cement.

Topoisomerase II inhibitors design: Early studies and new perspectives

The DNA topoisomerase enzymes are widely distributed throughout all spheres of life and are necessary for cell function. Numerous antibacterial and cancer chemotherapeutic drugs target the various topoisomerase enzymes because of their roles in maintaining DNA topology during DNA replication and transcription. Agents derived from natural products, like anthracyclines, epipodophyllotoxins and quinolones, have been widely used to treat a variety of cancers. A very active field of fundamental and clinical research is the selective targeting of topoisomerase II enzymes for cancer treatment. This thematic review summarizes the recent advances in the anticancer activity of the most potent topoisomerase II inhibitors (anthracyclines, epipodophyllotoxins and fluoroquinolones) their modes of action, and structure-activity relationships (SARs) organized chronologically in the last ten years from 2013 to 2023. The review also highlights the mechanism of action and SARs of promising new topoisomerase II inhibitors.

The Survival Outcomes, Prognostic Factors and Adverse Events following Systemic Chemotherapy Treatment in Bone Sarcomas: A Retrospective Observational Study from the Experience of the Cancer Referral Center in Northern Thailand

This study aimed to assess survival outcomes, prognostic factors, and adverse events following chemotherapy treatment for osteosarcoma and Ewing’s sarcoma. This retrospective observational study was conducted to collect the data of the patients with osteosarcoma or Ewing’s sarcoma who received chemotherapy treatment between 2008 and 2019. The flexible parametric survival model was performed to explore the adjusted survival probability and the prognostic factors. A total of 102 patients (79 with osteosarcoma and 23 with Ewing’s sarcoma) were included. The estimated 5-year disease-free survival (DFS) and 5-year overall survival (OS) probabilities in patients with resectable disease were 60.9% and 63.3% for osteosarcoma, and 54.4% and 88.3% for Ewing’s sarcoma, respectively, whereas the 5-year DFS and 5-year OS for those with unresectable/metastatic disease remained below 25%. Two prognostic factors for osteosarcoma included a response to neoadjuvant chemotherapy and female gender. Ewing’s sarcoma patients aged 25 years and older were significantly associated with poorer survival outcomes. Of 181 chemotherapy treatment cycles, common self-reported adverse symptoms included tumor pain (n = 32, 17.7%), fever (n = 21, 11.6%), and fatigue (n = 16, 8.8%), while common grade III adverse events included febrile neutropenia (n = 13, 7.3%) and neutropenia (n = 9, 5.1%). There was no chemotherapy-related mortality (grade V) or anaphylaxis events.

Ewing’s Sarcoma of the Zygoma: A Very Rare Location

Ewing's sarcoma is a rare and aggressive neoplasm that typically affects the long bones. The presence of a primary tumor in the facial bones is extremely uncommon. Here, we present a case of a 21-year-old male with Ewing's sarcoma of the zygoma. To date, only a few such cases have been reported worldwide in the literature.

Survival estimates of childhood malignancies treated at the Mexican telethon pediatric oncology hospital

BACKGROUND

Pediatric cancer incidence in Mexico is ~160/million/year with leukemias making 49.8% of the cases. While survival rates have been reported in various Mexican studies, no data is available from the Telethon Pediatric Oncology Hospital-HITO, a nonprofit private institution specialized exclusively in comprehensive pediatric oncology care in the country that closely follows high-income countries' advanced standards of cancer care.

AIM

To determine overall survival (OS) and relapse-free survival (RFS) in patients treated at HITO between December 2013 and February 2018.

METHODS AND RESULTS

Secondary analysis of data extracted from medical records. It included 286 children aged 0-17 years diagnosed with various cancers grouped into three categories based on location: (1) Acute lymphoblastic leukemia (ALL), (2) tumors within the central nervous system (TWCNS), and (3) tumors outside the CNS (TOCNS). OS and RFS rates for patients who completed 1 (n = 230) and 3 (n = 132) years of follow-up after admission were computed by sex, age, and cancer location, and separately for a subsample (1-year = 191, 3-years = 110) who fulfilled the HITO criteria (no prior treatment, underwent surgery/chemotherapy when indicated, and initiated therapy). TOCNS accounted for 45.1%, but ALL was the most frequent single diagnosis with 28%. Three-year OS for patients with ALL, TWCNS, and TOCNS who fulfilled the HITO criteria were 91.9%, 86.7%, and 79.3%, respectively; for 3-year RFS these were 89.2%, 60%, and 72.4%. Boys showed slightly higher OS and RFS, but no major differences or trends were seen by age group.

CONCLUSION

This study sets a relevant reference in terms of survival and relapse for children with cancer in Mexico treated at a private oncology center that uses a comprehensive and integrated therapeutic model.

Current Status and Prospects of Targeted Therapy for Osteosarcoma

Osteosarcoma (OS) is a highly malignant tumor occurring in bone tissue with a high propensity to metastasize, and its underlying mechanisms remain largely elusive. The OS prognosis is poor, and improving the survival of OS patients remains a challenge. Current treatment methods such as surgical approaches, chemotherapeutic drugs, and immunotherapeutic drugs remain ineffective. As research progresses, targeted therapy is gradually becoming irreplaceable. In this review, several treatment modalities for osteosarcoma, such as surgery, chemotherapy, and immunotherapy, are briefly described, followed by a discussion of targeted therapy, the important targets, and new technologies for osteosarcoma treatment.

Mediating effect assessment of ifosfamide on limb salvage rate in osteosarcoma: A study from a single center in China

Osteosarcoma is one of the most prevalent primary bone malignancies in children and adolescents. Surgery and chemotherapy are the standard treatment methods of osteosarcoma. Methotrexate, adriamycin, and cisplatin, and methotrexate, adriamycin, cisplatin, and ifosfamide regimens are both first-line neoadjuvant chemotherapy regimens for osteosarcoma. Moreover, the use of ifosfamide is highly controversial. Most studies of ifosfamide focused on the overall survival rate and event-free survival rate; few studies concentrated on surgical options. We conducted this retrospective study to compare the baseline characteristic of amputation and limb salvage osteosarcoma patients. Furthermore, we analyzed the direct and indirect roles in surgical decision-making and found that ifosfamide may play a partial mediating role in the surgery option choice by mediating tumor mass volume change, tumor response, and the shortest distance from the center of main blood vessels to the margin of the tumor lesion.

Primary Ewing’s sarcoma of sphenoid sinus: A case report and literature review

Background

Primary Ewing’s sarcoma of sphenoid sinus, observed in children and adolescents, is an extremely rare malignancy. Such rarity makes the imaging features and treatment strategies for Ewing’s sarcoma of sphenoid sinus unclear. This study aimed to offer guidance for treating this very disease by describing a patient with a rare primary Ewing’s sarcoma of sphenoid sinus and reviewing the available data in the literature.

Case description

A case of Ewing’s sarcoma in sphenoid sinus treated with multidisciplinary treatment approaches, including tumor resection, radiotherapy, chemotherapy, and antiangiogenic therapy, was presented in this study. Moreover, literature for Ewing’s sarcoma in the head was systematically searched, and two cases in the sphenoid sinus and five cases in the sphenoid bone were identified. Furthermore, the clinical features, imaging findings, pathological characteristics, treatment, and prognosis were summarized.

Conclusion

Tumor resection combined with radiotherapy and chemotherapy may provide favorable results for patients with Ewing’s sarcoma of sphenoid sinus and bone. However, more reports are still necessary to further clarify optimal management.

Solid pancreatic masses in children: A review of current evidence and clinical challenges

Pancreatic tumors in children are infrequently encountered in clinical practice. Their non-specific clinical presentation and overlapping imaging characteristics often make an accurate preoperative diagnosis difficult. Tumors are categorized as epithelial or non-epithelial, with epithelial tumors further classified as tumors of the exocrine or endocrine pancreas. Although both are tumors of the exocrine pancreas, solid pseudopapillary neoplasm is the most prevalent solid pancreatic tumor in children, while pancreatoblastoma is the most common malignant tumor. Insulinoma is the most common pediatric pancreatic tumor of the endocrine pancreas. Malignant tumors require a complete, often radical, surgical resection. However, pancreatic parenchyma-sparing surgical procedures are utilized for benign tumors and low-grade malignancy to preserve gland function. This review will discuss the epidemiology, pathophysiology, clinical and diagnostic characteristics, and management options associated with both common and rare solid pancreatic masses in children. We will also discuss current challenges encountered in their evaluation and treatment.

Monophasic Synovial Sarcoma in the Elbow Misclassified but Successfully Treated as Ewing's Sarcoma with Chemotherapy

To the best of the authors’ knowledge, this is the first published case of monophasic synovial sarcoma (SS) initially diagnosed as Ewing’s sarcoma (ES), yet successfully treated with chemotherapy in a 24-year-old patient. The initial diagnosis showed a monotonous round cell tumor and positivity for CD99, characteristic of ES; however, the cytology was negative for the classic EWSR1 rearrangement of ES. The patient was treated with the standard chemotherapy protocol of ES – COG AEWS1031 Regimen A with vincristine, doxorubicin, cyclophosphamide, and mesna – as well as with wide resection. Post-resection tissue submission showed additional morphologic features which led to a re-evaluation of the classification of the tumor as well as additional molecular studies; these revealed positivity for translocations of SS18 (18q11.1) in 100% of the nuclei, which is most characteristic of SS, thus, reclassifying the neoplasm as a SS tumor. This case underscores the importance of considering several pathologic entities in the differential diagnosis of small, round blue cell tumors, including ES, SS, and lymphoma. It also demonstrates the importance of using chromosomal identification for a more definitive diagnosis, rather than relying on histological features and markers which are found in more than one tumor classification. There is conflicting evidence of the impact of chemotherapy on survival in SS, as it is primarily treated with radiation therapy. Since SS is rare, prospective studies on the effect of chemotherapy on survival are limited in number. However, our case study demonstrates that chemotherapy is another modality that can be used in the treatment of SS neoplasms.

Pancreatic Masses in Children and Young Adults: Multimodality Review with Pathologic Correlation

Masses and masslike lesions of the pancreas are uncommon in the pediatric population. However, owing to overlapping clinical and imaging features, it can be challenging to differentiate the various causes of pediatric pancreatic masses at initial patient presentation. Clinical data such as patient age, signs and symptoms at presentation, laboratory test results, and potential underlying cancer predisposition syndrome can be helpful when formulating a differential diagnosis. US may be the first imaging study to depict a pancreatic mass in a child, as this examination is frequently performed in children with nonspecific abdominal signs and symptoms because of its wide availability and relatively low cost and the lack of a need for sedation or anesthesia. CT or MRI is typically required for more thorough characterization of the mass and surgical planning. Complete characterization of pancreatic masses includes assessment of vascular involvement, local invasion, and extrapancreatic spread of tumor. The authors provide an up-to-date comprehensive review of the clinical manifestations, histopathologic features, and imaging findings of primary and secondary tumors of the pancreas in children and young adults. Advances in imaging, current prognostic information, and treatment paradigms also are highlighted. Finally, nontumorous masslike lesions of the pediatric pancreas, including vascular malformations, cystic disorders (eg, von Hippel-Lindau syndrome, cystic fibrosis), intrapancreatic accessory spleen, and autoimmune pancreatitis, are discussed. Online supplemental material is available for this article. ^©RSNA, 2021.

Wide Surgery in the Cervical Spine: Indications, Results, and Complications in a Series of 30 Patients Affected by Primary Bone Tumors

BACKGROUND

En bloc surgery is the mainstay treatment for primary malignant bone tumors, as well as in the cervical spine. Unfortunately, literature on the topic is limited to case reports and small series.

METHODS

We reviewed all patients affected by primary cervical spine bone tumors treated with en bloc surgeries from 1996 to 2016 and identified 30 eligible cases. We evaluated the clinical presentation and tumor characteristics and reported surgical results, complications, recurrence, and survival rates.

RESULTS

Only 17 of 30 patients had not been previously treated at presentation. Osteosarcoma and chordoma were the most frequent tumors, and pain was reported in all cases. En bloc spondylectomy, hemispondylectomy, and posterior arch en bloc resection were performed in 16, 12, and 2 patients, respectively. The obtained margin was adequate (wide and marginal) in 60% of cases and intralesional in the remaining cases. Two deaths occurred in the immediate postoperative period. Neurological deterioration, dural tear, and dysphagia were the most frequent complications. The 5-year local recurrence-free survival was 70.4%. The recurrence rate was 38.5% and 11.7% in previously and non-previously treated patients, respectively (χ²: 2.94; P = 0.086). Overall survival at 5 years was 58% and 47% for all series and malignant tumors, respectively.

CONCLUSION

Primary cervical spine bone tumors present a difficult approach. Findings suggest that patients treated with en bloc surgery show recurrence and survival rates comparable to the same tumors located in the thoracolumbar spine.

Bone sarcoma: success through interdisciplinary collaboration

PURPOSE

Osteosarcoma and Ewing sarcoma are the most frequent malignant bone tumours of childhood and adolescence. This review summarizes the oncologist's view of these diseases and their treatment.

METHODS

A non-systematic literature review was performed, the personal impressions and experience of the authors is described.

RESULTS

Local therapy and chemotherapy, each on their own, will not cure patients with malignant bone sarcomas. Together, they present a highly efficacious combination. While the most effective drugs were defined decades ago, progress since then has been limited. It is hoped that substances shown to be active in relapsed disease will be forwarded into even more efficacious frontline treatments. Good palliative therapy is necessary when cure is no longer an option.

CONCLUSION

Close interdisciplinary collaboration is the key to successful treatment of bone sarcomas in paediatric patients.

Tissue-Engineered Bone Tumor as a Reproducible Human in Vitro Model for Studies of Anticancer Drugs

Studies of anticancer therapies in traditional cell culture models can demonstrate efficacy of direct-acting compounds but lack the 3-dimensional arrangement of the tumor cells and their tissue-specific microenvironments, both of which are important modulators of treatment effects in vivo. Bone cells reside in complex environments that regulate their fate and function. A bioengineered human bone-tumor model has been shown to provide a microphysiological niche for studies of cancer cell behavior. Here, we demonstrate successful transfer between 2 laboratories and utility of this model in efficacy studies using well-established chemotherapeutic agents. The bioengineered human bone-tumor model consisted of Ewing sarcoma (RD-ES) cancer cell aggregates infused into tissue-engineered bone that was grown from human mesenchymal stem cell-derived differentiated into osteoblasts within mineralized bone scaffolds. The tumor model was maintained in culture for over 5 weeks and subjected to clinically relevant doses of linsitinib, doxorubicin, cisplatin, methotrexate, vincristine, dexamethasone, or MAP (methotrexate, doxorubicin, and cisplatin combination). Drug administration cycles were designed to mimic clinical treatment regimens. The bioengineered tumors were evaluated days to weeks after the cessation of treatment to monitor the potential for relapse, using bioengineered bone and ES cell monolayers as controls. Drug binding to the scaffolds and media proteins and gene expression were also evaluated. We show that a bioengineered human bone tumor can be used as a microphysiological model for preclinical studies of anticancer drugs. We found that anticancer efficacy was achieved at concentrations approximating the human Cmax, in contrast to traditional ES cell monolayers. These studies show that the bone-tumor model can be successfully transferred between laboratories and has predictive power in preclinical studies. The effects of drugs on the bone tumors and healthy bone were studied in parallel, in support of the utility of this model for identification of new therapeutic targets.

Recent Developments in Nanomedicine for Pediatric Cancer

Cancer is the second biggest cause of death in children in the US. With the development of chemotherapy, there has been a substantial increase in the overall survival rate in the last 30 years. However, the overall mortality rate in children with cancer remains 25%, and many survivors experience a decline in overall quality of life and long-term adverse effects caused by treatments. Although cancer cells share common characteristics, pediatric cancers are different from adult cancers in their prevalence, mutation load, and drug response. Therefore, there is an urgent unmet need to develop therapeutic approaches specifically designed for children with cancer. Nanotechnology can potentially overcome the deficiencies of conventional methods of administering chemotherapy and ultimately improve clinical outcomes. The nanoparticle-based drug delivery systems can decrease the toxicity of therapy, provide a sustained or controlled drug release, improve the pharmacokinetic properties of loading contents, and achieve a targeted drug delivery with achievable modifications. Furthermore, therapeutic approaches based on combining nanoformulated drugs with novel immunotherapeutic agents are emerging. In this review, we discussed the recently developed nanotechnology-based strategies for treating blood and solid pediatric cancers.

Augmented Antitumor Activity for Novel Dual PI3K/BDR4 Inhibitors, SF2523 and SF1126 in Ewing Sarcoma

Ewing sarcoma (ES) is the second most common pediatric bone cancer. Despite recent advances in the treatment, patients with metastatic tumors have dismal prognosis and hence novel therapies are urgently needed to combat this cancer. A recent study has shown that phosphoinositide-3 kinase (PI3K) inhibitors can synergistically increase sensitivity to bromodomain and extraterminal domain inhibitors in ES cells and therefore combined inhibition of PI3K and bromodomain and extraterminal domain bromodomain proteins might provide benefit in this cancer. Herein, we have investigated the efficacy of dual PI3K/BRD4 inhibitors, SF2523 and SF1126, for their antitumor activity in ES cell lines. The effect of SF1126 and SF2523 on cell viability and PI3K signaling was assessed on a panel of human ES cell lines. To evaluate the antitumor activity of SF1126, A673 cells were injected intrafemorally into RAG-2-/- mice and treated with 50 mg/kg SF1126 6 days per week, for 30 days. Both SF1126 and SF2523 decreased cell survival and inhibited phosphorylation of AKT in human ES cell lines. In vivo, SF1126 showed a significant reduction in tumor volume. These results suggest that dual PI3K/BRD4 inhibitor, SF1126, has antitumor activity in ES models.

Sarcoma treatment in the era of molecular medicine

Sarcomas are heterogeneous and clinically challenging soft tissue and bone cancers. Although constituting only 1% of all human malignancies, sarcomas represent the second most common type of solid tumors in children and adolescents and comprise an important group of secondary malignancies. More than 100 histological subtypes have been characterized to date, and many more are being discovered due to molecular profiling. Owing to their mostly aggressive biological behavior, relative rarity, and occurrence at virtually every anatomical site, many sarcoma subtypes are in particular difficult-to-treat categories. Current multimodal treatment concepts combine surgery, polychemotherapy (with/without local hyperthermia), irradiation, immunotherapy, and/or targeted therapeutics. Recent scientific advancements have enabled a more precise molecular characterization of sarcoma subtypes and revealed novel therapeutic targets and prognostic/predictive biomarkers. This review aims at providing a comprehensive overview of the latest advances in the molecular biology of sarcomas and their effects on clinical oncology; it is meant for a broad readership ranging from novices to experts in the field of sarcoma.

Inactivation of ICAM1 inhibits metastasis and improves the prognosis of Ewing's sarcoma

BACKGROUND

Ewing's sarcoma (ES) is a kind of malignant tumor, which often occurs in the long bone, pelvis, and other bone tissues, as well as some soft tissues. It often occurs in children and adolescents, second only to osteosarcoma and rhabdomyosarcoma. In the past 30 years, little progress has been made on the genomic mechanism of ES metastasis.

METHODS

The gene expression sequence of ES metastasis samples was compared with that of primary tumor samples to obtain differentially expressed genes (DEGs). Subsequently, we annotated the gene functions and enriched pathways of DEGs. Additionally, the protein and protein interaction network were constructed to screen key genes that can lead to the metastasis in ES. Then, cell and molecular biology experiments were conducted to verify the results obtained from the bioinformatics analysis. Finally, we assessed the correlation of expression between the key genes EWSR and FLI1, and conducted a survival analysis of ICAM1.

RESULTS

Our study revealed 153 DEGs. Of these, 82 (53.59%) were upregulated and the remaining 71 (46.41%) were downregulated. The bioinformatics analysis showed that ICAM1 was the key gene leading to the invasion and metastasis of ES. Through cell biology and molecular biology experiments, inactivation of ICAM1 inhibited the metastasis of ES cells. The survival and correlation analyses showed that ICAM1 was a risk factor in patients with ES, and that ICAM1 expression was correlated with EWSR and FLI1 expression.

CONCLUSION

Our study shows that inactivation of ICAM1 inhibits metastasis and improves the prognosis of ES. Additionally, our findings provide a better understanding of the underlying mechanisms of metastatic ES, a basis for an accurate diagnosis, and therapeutic targets for ES patients.

Optimizing an Osteosarcoma-Fibroblast Coculture Model to Study Antitumoral Activity of Magnesium-Based Biomaterials

Osteosarcoma is among the most common cancers in young patients and is responsible for one-tenth of all cancer-related deaths in children. Surgery often leads to bone defects in excised tissue, while residual cancer cells may remain. Degradable magnesium alloys get increasing attention as orthopedic implants, and some studies have reported potential antitumor activity. However, most of the studies do not take the complex interaction between malignant cells and their surrounding stroma into account. Here, we applied a coculture model consisting of green fluorescent osteosarcoma cells and red fluorescent fibroblasts on extruded Mg and Mg-6Ag with a tailored degradation rate. In contrast to non-degrading Ti-based material, both Mg-based materials reduced relative tumor cell numbers. Comparing the influence of the material on a sparse and dense coculture, relative cell numbers were found to be statistically different, thus relevant, while magnesium alloy degradations were observed as cell density-independent. We concluded that the sparse coculture model is a suitable mechanistic system to further study the antitumor effects of Mg-based material.

Modeling the Tumor Microenvironment and Pathogenic Signaling in Bone Sarcoma

Investigations of cancer biology and screening of potential therapeutics for efficacy and safety begin in the preclinical laboratory setting. A staple of most basic research in cancer involves the use of tissue culture plates, on which immortalized cell lines are grown in monolayers. However, this practice has been in use for over six decades and does not account for vital elements of the tumor microenvironment that are thought to aid in initiation, propagation, and ultimately, metastasis of cancer. Furthermore, information gleaned from these techniques does not always translate to animal models or, more crucially, clinical trials in cancer patients. Osteosarcoma (OS) and Ewing sarcoma (ES) are the most common primary tumors of bone, but outcomes for patients with metastatic or recurrent disease have stagnated in recent decades. The unique elements of the bone tumor microenvironment have been shown to play critical roles in the pathogenesis of these tumors and thus should be incorporated in the preclinical models of these diseases. In recent years, the field of tissue engineering has leveraged techniques used in designing scaffolds for regenerative medicine to engineer preclinical tumor models that incorporate spatiotemporal control of physical and biological elements. We herein review the clinical aspects of OS and ES, critical elements present in the sarcoma microenvironment, and engineering approaches to model the bone tumor microenvironment. Impact statement The current paradigm of cancer biology investigation and therapeutic testing relies heavily on monolayer, monoculture methods developed over half a century ago. However, these methods often lack essential hallmarks of the cancer microenvironment that contribute to tumor pathogenesis. Tissue engineers incorporate scaffolds, mechanical forces, cells, and bioactive signals into biological environments to drive cell phenotype. Investigators of bone sarcomas, aggressive tumors that often rob patients of decades of life, have begun to use tissue engineering techniques to devise in vitro models for these diseases. Their efforts highlight how critical elements of the cancer microenvironment directly affect tumor signaling and pathogenesis.

Establishment and Characterization of a Recurrent Osteosarcoma Cell Line: OSA 1777

Osteosarcoma (OSA) is the most common primary bone malignancy overall and is responsible for considerable adolescent mortality. Approximately 850 patients are newly diagnosed with OSA in the United States each year. While the 5-year survival rate for localized OSA has improved from <20% over 40 years ago to over 65% today, progress has dwindled over the past three decades. Therapeutic stagnation has occurred, in part, as a result of limited preclinical models and the overall heterogeneity of OSA among patients. In this study, we report the establishment and characterization of a novel OSA cell line: OSA 1777. This cell line was isolated from the recurrent tumor specimen of a 19-year-old female who initially experienced 99% tumor necrosis after neoadjuvant chemotherapy and eventually had local recurrence and metastases. We present OSA 1777 growth characteristics, tumor markers, chemotherapeutic sensitivities, and oncogenic spheroid formation. In a two-dimensional (2D) monolayer culture, OSA 1777 exhibited a spindle shape and 60 h doubling time. STR DNA profiling revealed a unique genomic identity not matching any existing human cancer cell lines from the ATCC or DSMZ databases. Consistent with the mesenchymal origin, western blot was positive for vimentin and negative for the carcinoma marker cytokeratin. Within three-dimensional (3D) culture, the cells formed spheroids of similar patterning and smaller size compared with MNNG-HOS and U2OS cell lines. The chemotherapeutic drug sensitivity of OSA 1777 was evaluated in both 2D and 3D culture systems. In summary, we report OSA 1777 as a novel biological model of OSA amenable to future studies focused on OSA that recurs despite an initially strong chemotherapeutic response. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 38:902-910, 2020.

Omic approaches to pediatric bone sarcomas

Over the last decade, next-generation sequencing technologies have improved our ability to assess biological aspects, at genomic and transcriptomic levels, on a large scale- and have been increasingly used for the management of adult cancers. However, their efficacy and feasibility within pediatrics is still under investigation. "Omic" approaches represent an opportunity to understand the oncogenic mechanisms driving the onset and progression of bone sarcoma and improve the clinical management of young patients with bone sarcomas. This review focuses on the current genomic and transcriptomic characteristics of managing pediatric patients, affected by Ewing sarcoma and osteosarcoma.

Apatinib ameliorates doxorubicin-induced migration and cancer stemness of osteosarcoma cells by inhibiting Sox2 via STAT3 signalling

Background

Osteosarcoma, ranking as the second primary cause of cancer-related death, is the most common type of bone cancer. Doxorubicin (DOX) is used as a first-line treatment for osteosarcoma; however, the tumour recurrence rate remains high. Recent studies have suggested that DOX-induced migration and stemness in osteosarcoma cells might be the primary reason of recurrence and drug resistance. However, the underlying mechanisms remain unclear. Therefore, it is urgent to explore novel effective treatments to overcome DOX-induced drug resistance of osteosarcoma.

Methods

Osteosarcoma cells KHOS and U2OS were treated with DOX and apatinib (AP) alone or in combination. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and colony formation assays were performed to evaluate effects on proliferation. Flow cytometry analysis was carried out to assess cell apoptosis. Cell migration was determined by the transwell assay. Cancer stemness was detected by flow cytometry analysis of CD133⁺ cells and sphere-formation assay. Western blot assay was used to measure the expression of E-cadherin, N-cadherin, vimentin, matrix metalloproteinase 9 (MMP-9), signal transducer and activator of transcription 3 (STAT3)/p-STAT3, SRY-box2 (Sox2) and octamer-binding protein 4 (Oct4), and Nanog in treated osteosarcoma cells.

Results

Herein, we revealed that AP treatment significantly enhanced the sensitivity of osteosarcoma cells to DOX, reversed the DOX-induced stemness phenotype and metastasis capacity of osteosarcoma cells, and abolished the upregulation of p-STAT3, Sox2, Oct4, and Nanog. We further demonstrated that AP reversed DOX-induced stemness and migration of osteosarcoma cells through Sox2.

Conclusion

These results suggested that AP significantly abolished the DOX-induced stemness phenotype and metastasis capacity in osteosarcoma cells by inhibiting Sox2 via STAT3 signalling.

The translational potential of this article

Our study indicates that Doxorubicin-based chemotherapeutics may simulate cancer stem cells (CSCs) properties in osteosarcoma, leading to the resistance of osteosarcoma. Apatinib can reduce the Doxorubicin-induced chemoresistance through STAT3/Sox2 pathway inactivation. This study represents that Apatinib may act as an effective chemotherapy sensitiser for reducing chemoresistance correlated with CSCs in osteosarcoma.

Inhibitory effects of indirubin-3'-monoxime against human osteosarcoma

Indirubin is widely used as the active component of "Dangui Luhui Wan" in ancient China. However, its effects against the osteosarcoma (OS), the most common primary malignancy, are still unknown. In our present study, we investigated the effects of the Indirubin-3'-monoxime (I3M), a derivative of indirubin with better water solubility, against the OS cells. We found I3M inhibited OS cell proliferation in a dose-dependent manner. Flow cytometry assays showed that I3M could not only induce OS cell apoptosis in a time- and dose-dependent manner but also regulate the cell cycle distribution. Additionally, we demonstrated that several Bcl-2 family members, cyclin-dependent kinases (CDKs) and cyclins contributed to this process. Furthermore, out data verified that I3M suppressed OS cell migration and invasion by decreasing MMP-2 and MMP-9 levels. Moreover, survivin and focal adhesion kinase (FAK) might play important roles in the anti-OS effects of I3M. The administration of I3M also inhibited the OS cell growth in mice. Taken together, our results indicated the inhibitory effects of I3M against human OS and thus might be an efficient candidate for OS chemotherapy.

Predicting Ewing Sarcoma Treatment Outcome Using Infrared Spectroscopy and Machine Learning

Background: Improved outcome prediction is vital for the delivery of risk-adjusted, appropriate and effective care to paediatric patients with Ewing sarcoma—the second most common paediatric malignant bone tumour. Fourier transform infrared (FTIR) spectroscopy of tissues allows the bulk biochemical content of a biological sample to be probed and makes possible the study and diagnosis of disease. Methods: In this retrospective study, FTIR spectra of sections of biopsy-obtained bone tissue were recorded. Twenty-seven patients (between 5 and 20 years of age) with newly diagnosed Ewing sarcoma of bone were included in this study. The prognostic value of FTIR spectra obtained from Ewing sarcoma (ES) tumours before and after neoadjuvant chemotherapy were analysed in combination with various data-reduction and machine learning approaches. Results: Random forest and linear discriminant analysis supervised learning models were able to correctly predict patient mortality in 92% of cases using leave-one-out cross-validation. The best performing model for predicting patient relapse was a linear Support Vector Machine trained on the observed spectral changes as a result of chemotherapy treatment, which achieved 92% accuracy. Conclusion: FTIR spectra of tumour biopsy samples may predict treatment outcome in paediatric Ewing sarcoma patients with greater than 92% accuracy.

A combination of irinotecan/cisplatinum and irinotecan/temozolomide or tumor-targeting Salmonella typhimurium A1-R arrest doxorubicin- and temozolomide-resistant myxofibrosarcoma in a PDOX mouse model

Myxofibrosarcoma (MFS) is the most common sarcomas in elderly patients and is either chemo-resistant or recurs with metastasis after chemotherapy. This recalcitrant cancer in need of improved treatment. We have established a patient-derived orthotopic xenograft (PDOX) of MFS. The MFS PDOX model was established in the biceps femoris of nude mice and randomized into 7 groups of 7 mice each: control; doxorubicin (DOX); pazopanib (PAZ); temozolomide (TEM); Irinotecan (IRN); IRN combined with TEM; IRN combined with cisplatinum (CDDP) and Salmonella typhimurium A1-R (S. typhimurium A1-R). Treatment was evaluated by relative tumor volume and relative body weight. The MFS PDOX models were DOX, PAZ, and TEM resistant. IRN combined with TEM and IRN combined with CDDP were most effective on the MFS PDOX. S. typhimurium A1-R arrested the MFS PDOX tumor. There was no significant body weight loss in any group. The present study suggests that the combination of IRN with either TEM or CDDP, and S. typhimurium have clinical potential for MFS.

Survival after second and subsequent recurrences in osteosarcoma: a retrospective multicenter analysis

PURPOSE

Osteosarcoma (OS) is the most common primary bone tumor. Despite complete surgical removal and intensive chemotherapeutic treatment, 30%-35% of patients with OS have local or systemic recurrence. Some patients survive multiple recurrences, but overall survival after OS recurrence is poor. This analysis aims to describe and identify factors influencing post-relapse survival (PRS) after a second OS relapse.

METHODS

This is a retrospective analysis of 60 patients with a second relapse of OS of the extremities in 2 Italian centers between 2003 and 2013.

RESULTS

Treatment for first and subsequent relapses was planned according to institutional guidelines. After complete surgical remission (CSR) following the first recurrence, patients experienced a second OS relapse with a median disease-free interval (DFI) of 6 months. Lung disease was prevalent: 44 patients (76%) had pulmonary metastases. Survival after the second relapse was 22% at 5 years. Lung disease only correlated with better survival at 5 years (33.6%) compared with other sites of recurrence (5%; p = 0.008). Patients with a single pulmonary lesion had a better 5-year second PRS (42%; p = 0.02). Patients who achieved a second CSR had a 5-year second PRS of 33.4%. Chemotherapy (p<0.001) benefited patients without a third CSR.

CONCLUSIONS

This analysis confirms the importance of an aggressive, repeated surgical approach. Lung metastases only, the number of lesions, DFI and CSR influenced survival. It also confirms the importance of chemotherapy in patients in whom surgical treatment is not feasible.

Prognostic determinants and treatment outcomes analysis of osteosarcoma and Ewing sarcoma of the spine

BACKGROUND CONTEXT

Osteosarcoma (OGS) and Ewing sarcoma (EWS) are the two classic primary malignant bone tumors. Due to the rarity of these tumors, evidence on demographics, survival determinants, and treatment outcomes for primary disease of the spine are limited and derived from small case series.

PURPOSE

To use population-level data to determine the epidemiology and prognostic indicators in patients with OGS and EWS of the osseous spine.

STUDY DESIGN/SETTING

Large-scale retrospective study.

PATIENT SAMPLE

Patients diagnosed with OGS and EWS of the spine in the Surveillance, Epidemiology, and End Results (SEER) registry from 1973 to 2012.

OUTCOME MEASURES

Overall survival (OS) and disease-specific survival (DSS).

METHODS

Two separate queries of the SEER registry were performed to identify patients with OGS and EWS of the osseous spine from 1973-2012. Study variables included age, sex, race, year of diagnosis, tumor size, extent of disease (EOD), and treatment with surgery and/or radiation therapy. Primary outcome was defined as OS and DSS in months. Univariate survival analysis was performed using the Kaplan-Meier method and the log-rank test. Multivariate analysis was performed using Cox proportional hazards regression models.

RESULTS

The search identified 648 patients with primary OGS and 736 patients with primary EWS of the spine from 1973 to 2012. Mean age at diagnosis was 48.1 and 19.9 years for OGS and EWS, respectively, with OGS showing a bimodal distribution. The median OS and DSS were 1.3 and 1.7 years, respectively, for OGS, with OGS in Paget's disease having worse OS (0.7 years) relative to the mean (log-rank p=.006). The median OS and DSS for EWS were 3.9 and 4.3 years, respectively. Multivariate cox regression analysis showed that age (OS p<.001, DSS p<.001), decade of diagnosis (OS p=.049), surgical resection (OS p<.001, DSS p<.001), and EOD (OS p<.001, DSS p<.001) were independent positive prognostic indicators for spinal OGS; radiation therapy predicted worse OS (hazard ratio [HR] 1.48, confidence interval [CI] 1.05-2.10, p=.027) and DSS (HR 1.74, CI 1.13-2.66, p=.012) for OGS. For EWS, age (OS p<.001, DSS p<.001), surgical resection (OS p=.030, DSS p=.046), tumor size (OS p<.001, DSS p<.001), and EOD (OS p<.001, DSS p<.001) were independent determinants of improved survival; radiation therapy trended toward improved survival but did not achieve statistical significance for both OS (HR 0.76, CI 0.54-1.07, p=.113) and DSS (0.76, CI 0.54, 1.08, p=.126).

CONCLUSIONS

Age, surgical resection, and EOD are key survival determinants for both OGS and EWS of the spine. Radiation therapy may be associated with worse outcomes in patients with OGS, and is of potential benefit in EWS. Overall prognosis has improved in patients with OGS of the spine over the last four decades.

Autologous hematopoietic stem cell transplantation following high-dose chemotherapy for nonrhabdomyosarcoma soft tissue sarcomas

BACKGROUND

Soft tissue sarcomas (STS) are a highly heterogeneous group of rare malignant solid tumors. Nonrhabdomyosarcoma soft tissue sarcomas (NRSTS) comprise all STS except rhabdomyosarcoma. In people with advanced local or metastatic disease, autologous hematopoietic stem cell transplantation (HSCT) applied after high-dose chemotherapy (HDCT) is a planned rescue therapy for HDCT-related severe hematologic toxicity. The rationale for this update is to determine whether any randomized controlled trials (RCTs) have been conducted and to clarify whether HDCT followed by autologous HSCT has a survival advantage.

OBJECTIVES

To assess the efficacy and safety of high-dose chemotherapy (HDCT) followed by autologous hematopoietic stem cell transplantation (HSCT) for all stages of nonrhabdomyosarcoma soft tissue sarcomas (NRSTS) in children and adults.

SEARCH METHODS

For this update, we revised the search strategy to improve the precision and reduce the number of irrelevant hits. We searched the following electronic databases: Cochrane Central Register of Controlled Trials (CENTRAL; 2016, Issue 8), PubMed from 2012 to 6 September 2016, and Embase from 2012 to 26 September 2016. We searched online trial registries and congress proceedings from 2012 to 26 September 2016.

SELECTION CRITERIA

Terms representing STS and autologous HSCT were required in the title or abstract. We restricted the study design to RCTs. We included studies if at least 80% of participants had a diagnosis listed in any version of the World Health Organization (WHO) classification and classified as malignant. The search included children and adults with no age limits.

DATA COLLECTION AND ANALYSIS

We used standard methodologic procedures expected by Cochrane. The primary outcomes were overall survival and treatment-related mortality.

MAIN RESULTS

We identified 1549 records; 85 items from electronic databases, 45 from study registries, and 1419 from congress proceedings. The revised search strategy did not identify any additional RCTs. In the previous version of the review, we identified one RCT comparing HDCT followed by autologous HSCT versus standard-dose chemotherapy (SDCT). The trial randomized 87 participants who were considerably heterogeneous with respect to 19 different tumor entities. The data from 83 participants were available for analysis.In the single included trial, overall survival at three years was 32.7% in the HDCT arm versus 49.4% in the SDCT arm and there was no difference between the treatment groups (hazard ratio (HR) 1.26, 95% confidence interval (CI) 0.70 to 2.29, P = 0.44; 1 study, 83 participants; high quality evidence). In a subgroup of participants who had a complete response before HDCT, overall survival was higher in both treatment groups and overall survival at three years was 42.8% in the HDCT arm versus 83.9% in the SDCT arm and favored the SDCT group (HR 2.92, 95% CI 1.1 to 7.6, P = 0.028; 1 study, 39 participants).In the single included trial, the authors reported one treatment-related leukemia death two years after HDCT. They also evaluated severe adverse events WHO grade 3 to 4 in 22 participants in the HDCT arm and in 51 participants in the SDCT arm. The authors reported 11 events concerning digestive-, infection-, pain-, or asthenia-related toxicity in the HDCT arm and one event in the SDCT arm (moderate quality evidence). The development of secondary neoplasia was not addressed. We judged the study to have an overall unclear risk of bias as three of seven items had unclear and four items had low risk of bias. For GRADE, we judged three items as high quality and three items were not reported.

AUTHORS' CONCLUSIONS

The limited data of a single RCT with an unclear risk of bias and moderate to high quality evidence showed no survival advantage for HDCT. If this treatment is offered it should only be given after careful consideration on an individual person basis and possibly only as part of a well-designed RCT.

Immune Therapy for Sarcomas

Absolute lymphocyte count (ALC) recovery rapidly occurring at 14 days after start of chemotherapy for osteosarcoma and Ewing sarcoma is a good prognostic factor. Conversely, lymphopenia is associated with significantly decreased sarcoma survival. Clearly, the immune system can contribute towards better survival from sarcoma. This chapter will describe treatment and host factors that influence immune function and how effective local control and systemic interventions of sarcoma therapy can cause inflammation and/or immune suppression but are currently the standard of care. Preclinical and clinical efforts to enhance immune function against sarcoma will be reviewed. Interventions to enhance immune function against sarcoma have included regional therapy (surgery, cryoablation, radiofrequency ablation, electroporation, and radiotherapy), cytokines, macrophage activators (mifamurtide), vaccines, natural killer (NK) cells, T cell receptor (TCR) and chimeric antigen receptor (CAR) T cells, and efforts to decrease inflammation. The latter is particularly important because of new knowledge about factors influencing expression of checkpoint inhibitory molecules, PD1 and CTLA-4, in the tumor microenvironment. Since these molecules can now be blocked using anti-PD1 and anti-CTLA-4 antibodies, how to translate this knowledge into more effective immune therapies in the future as well as how to augment effectiveness of current interventions (e.g., radiotherapy) is a challenge. Barriers to implementing this knowledge include cost of agents that release immune checkpoint blockade and coordination of cost-effective outpatient sarcoma treatment. Information on how to research clinical trial eligibility criteria and how to access current immune therapy trials against sarcoma are shared, too.

Osteosarcoma With Apparent Ewing Sarcoma Gene Rearrangement

Poorly differentiated round cell sarcomas present diagnostic challenges because of their variable morphology and lack of specific immunophenotypic markers. We present a case of a 15-year-old female with a tibial tumor that exhibited features of Ewing-like sarcoma, including apparent rearrangement of the EWSR1 gene. Hybridization capture-based next-generation DNA sequencing showed evidence of complex genomic rearrangements, absence of known pathogenic Ewing-like chromosome translocations, and deletions RB1, PTCH1, and ATRX, supporting the diagnosis of osteosarcoma. This illustrates the potential of clinical genomic profiling to improve diagnosis and enable specifically targeted therapies for cancers with complex pathologies.