Cabozantinib in patients with advanced Ewing sarcoma or osteosarcoma (CABONE): a multicentre, single-arm, phase 2 trial

CT-derived Radiomics Predicts the Efficacy of Tyrosine Kinase Inhibitors in Osteosarcoma Patients with Pulmonary Metastasis

BACKGROUND

To construct and validate the CT-based radiomics model for predicting the tyrosine kinase inhibitors (TKIs) effects in osteosarcoma (OS) patients with pulmonary metastasis.

METHODS

OS patients with pulmonary metastasis treated with TKIs were randomly separated into training and testing cohorts (2:1 ratio). Radiomic features were extracted from the baseline unenhanced chest CT images. The random survival forest (RSF) and Kaplan-Meier survival analyses were performed to construct and evaluate radiomics signatures (R-model-derived). The univariant and multivariant Cox regression analyses were conducted to establish clinical (C-model) and combined models (RC-model). The discrimination abilities, goodness of fit and clinical benefits of the three models were assessed and validated in both training and testing cohorts.

RESULTS

A total of 90 patients, 57 men and 33 women, with a mean age of 18 years and median progression-free survival (PFS) of 7.2 months, were enrolled. The R-model was developed with nine radiomic features and demonstrated significant predictive and prognostic values. In both training and testing cohorts, the time-dependent area under the receiver operating characteristic curves (AUC) of the R-model and RC-model exhibited obvious superiority over C-model. The calibration and decision curve analysis (DCA) curves indicated that the accuracy of the R-model was comparable to RC-model, which exhibited significantly better performance than C-model.

CONCLUSIONS

The R-model showed promising potential as a predictor for TKI responses in OS patients with pulmonary metastasis. It can potentially identify pulmonary metastatic OS patients most likely to benefit from TKIs treatment and help guide optimized clinical decisions.

Emerging therapies in Ewing sarcoma

PURPOSE OF REVIEW

There is an unmet need to improve outcomes for patients for Ewing sarcoma, a rare, aggressive sarcoma with a peak incidence in adolescents and young adults (AYA). Current therapy at diagnosis involves multiagent chemotherapy and local therapy, but despite intensification of treatment, those with metastases at diagnosis and recurrent disease have poor outcomes.

RECENT FINDINGS

Improved understanding of Ewing sarcoma biology has identified novel targets with promising activity in Ewing sarcoma patients, including tyrosine kinase inhibitors that are now undergoing evaluation as combination and maintenance therapy. Other emerging therapies include those that target the EWSR1::FLI1 fusion oncoprotein, and act on DNA damage, cell cycle and apoptotic pathways. Immunotherapeutic approaches, particularly CAR-T-cell therapy directed at GD2, also hold promise. Recent collaborative clinical trials that have defined an international standard of care for patients with newly diagnosed Ewing sarcoma and novel platform studies with adaptive designs offer unique opportunities to investigate these therapies inclusive of all ages.

SUMMARY

Close international collaboration between clinicians and biologists will allow us to prioritize promising emerging therapies and develop biomarkers to facilitate their incorporation into standard of care and more rapidly translate into benefit for Ewing sarcoma patients.

Sarcoma_CellminerCDB: A tool to interrogate the genomic and functional characteristics of a comprehensive collection of sarcoma cell lines

Sarcomas are a diverse group of rare malignancies composed of multiple different clinical and molecular subtypes. Due to their rarity and heterogeneity, basic, translational, and clinical research in sarcoma has trailed behind that of other cancers. Outcomes for patients remain generally poor due to an incomplete understanding of disease biology and a lack of novel therapies. To address some of the limitations impeding preclinical sarcoma research, we have developed Sarcoma_CellMinerCDB, a publicly available interactive tool that merges publicly available sarcoma cell line data and newly generated omics data to create a comprehensive database of genomic, transcriptomic, methylomic, proteomic, metabolic, and pharmacologic data on 133 annotated sarcoma cell lines. The reproducibility, functionality, biological relevance, and therapeutic applications of Sarcoma_CellMinerCDB described herein are powerful tools to address and generate biological questions and test hypotheses for translational research. Sarcoma_CellMinerCDB (https://discover.nci.nih.gov/SarcomaCellMinerCDB) aims to contribute to advancing the preclinical study of sarcoma.

Prolonged 14-day continuous infusion of high-dose ifosfamide for patients with relapsed and refractory high-grade osteosarcoma: a retrospective multicentre cohort study

BACKGROUND

The prognosis of patients with Relapsed/Refractory Osteosarcoma (R/R OS) remains dismal without an agreement on systemic therapy. The use of High-Dose Ifosfamide (14 g/sqm) with an external pump in outpatient setting (14-IFO) in R/R OS patients is limited. This study represents the first retrospective cohort analysis focused on evaluating the activity and toxicity of 14-IFO in this setting.

PATIENTS AND METHODS

The study investigated 14-IFO activity, in terms of tumour response according to RECIST 1.1 criteria, as well as survival rates and toxicity, according to CTCAE v.5.

RESULTS

The trial enrolled 26 patients with R/R OS. The Overall Response Rate (ORR) and Disease Control Rate (DCR) obtained was 23% and 57.5%, respectively. Patients with relapsed OS showed a higher ORR (45%) and DCR (82%) compared to refractory patients, irrespective of the number of prior treatment lines received. The achievement of disease control with 14-IFO administration enabled 27% of patients to undergo new local treatment. Four-month Progression-Free Survival (PFS) was 54% for all patients and 82% for the relapsed OS sub-group. Median Overall Survival (OSurv) was 13.7 months, with 1-year OSurv of 51% for all patients and 71% for relapsed patients. Age over 18 years and the presence of refractory disease were identified as negative prognostic factors for this patient cohort. A total of 101 cycles were evaluated for toxic assessment, demonstrating a tolerable profile without grade 3-4 non-haematological toxicities.

CONCLUSIONS

14-IFO should be considered a viable treatment option for R/R OS, particularly due to its well tolerated toxicity profile and the potential for home-administration, which can improve patient quality of life without compromising efficacy.

From biology to personalized medicine: Recent knowledge in osteosarcoma

High-grade osteosarcoma is the most common paediatric bone cancer. More than one third of patients relapse and die of osteosarcoma using current chemotherapeutic and surgical strategies. To improve outcomes in osteosarcoma, two crucial challenges need to be tackled: 1-the identification of hard-to-treat disease, ideally from diagnosis; 2- choosing the best combined or novel therapies to eradicate tumor cells which are resistant to current therapies leading to disease dissemination and metastasize as well as their favorable microenvironment. Genetic chaos, tumor complexity and heterogeneity render this task difficult. The development of new technologies like next generation sequencing has led to an improvement in osteosarcoma oncogenesis knownledge. This review summarizes recent biological and therapeutical advances in osteosarcoma, as well as the challenges that must be overcome in order to develop personalized medicine and new therapeutic strategies and ultimately improve patient survival.

Identifying Genetic Signatures Associated with Oncogene-Induced Replication Stress in Osteosarcoma and Screening for Potential Targeted Drugs

Osteosarcoma is the most common type of primary malignant bone tumor. Due to the lack of selectivity and sensitivity of chemotherapy drugs to tumor cells, coupled with the use of large doses, chemotherapy drugs often have systemic toxicity. The use of modern sequencing technology to screen tumor markers in a large number of tumor samples is a common method for screening highly specific and selective anti-tumor drugs. This study aims to identify potential biomarkers using the latest reported gene expression signatures of oncogene-induced replication stress (ORS) in aggressive cancers, and potential anti-osteosarcoma drugs were screened in different drug databases. In this study, we obtained 89 osteosarcoma-related samples in the TARGET database, all of which included survival information. According to the median expression of each of six reported ORS gene markers (NAT10/DDX27/ZNF48/C8ORF33/MOCS3/MPP6), we divided 89 osteosarcoma gene expression datasets into a high expression group and a low expression group and then performed a differentially expressed gene (DEG) analysis. The coexisting genes of 6 groups of DEGs were used as replication stress-related genes (RSGs) of osteosarcoma. Then, key RSGs were screened using LASSO regression, a Cox risk proportional regression prognostic model and a tenfold cross-validation test. GSE21257 datasets collected from the Gene Expression Omnibus (GEO) database were used to verify the prognostic model. The final key RSGs selected were used in the L1000PWD and DGIdb databases to mine potential drugs. After further validation by the prognostic model, we identified seven genes associated with ORS in osteosarcoma as key RSGs, including transcription factor 7 like 2 (TCF7L2), solute carrier family 27 member 4 (SLC27A4), proprotein convertase subtilisin/kexin type 5 (PCSK5), nucleolar protein 6 (NOL6), coiled-coil-coil-coil-coil-helix domain containing 4 (CHCHD4), eukaryotic translation initiation factor 3 subunit B (EIF3B), and synthesis of cytochrome C oxidase 1 (SCO1). Then, we screened the seven key RSGs in two drug databases and found six potential anti-osteosarcoma drugs (D GIdb database: repaglinide, tacrolimus, sirolimus, cyclosporine, and hydrochlorothiazide; L1000PWD database: the small molecule VU-0365117-1). Seven RSGs (TCF7L2, SLC27A4, PCSK5, NOL6, CHCHD4, EIF3B, and SCO1) may be associated with the ORS gene signatures in osteosarcoma. Repaglinide, tacrolimus, sirolimus, cyclosporine, hydrochlorothiazide and the small molecule VU-0365117-1 are potential therapeutic drugs for osteosarcoma.

Immunological role of Gas6/TAM signaling in hemostasis and thrombosis

The immune system is an emerging regulator of hemostasis and thrombosis. The concept of immunothrombosis redefines the relationship between coagulation and immunomodulation, and the Gas6/Tyro3-Axl-MerTK (TAM) signaling pathway builds the bridge across them. During coagulation, Gas6/TAM signaling pathway not only activates platelets, but also promotes thrombosis through endothelial cells and vascular smooth muscle cells involved in inflammatory responses. Thrombosis appears to be a common result of a Gas6/TAM signaling pathway-mediated immune dysregulation. TAM TK and its ligands have been found to be involved in coagulation through the PI3K/AKT or JAK/STAT pathway in various systemic diseases, providing new perspectives in the understanding of immunothrombosis. Gas6/TAM signaling pathway serves as a breakthrough target for novel therapeutic strategies to improve disease management. Many preclinical and clinical studies of TAM receptor inhibitors are in process, confirming the pivotal role of Gas6/TAM signaling pathway in immunothrombosis. Therapeutics targeting the TAM receptor show potential both in anticoagulation management and immunotherapy. Here, we review the immunological functions of the Gas6/TAM signaling pathway in coagulation and its multiple mechanisms in diseases identified to date, and discuss the new clinical strategies that may generated by these roles.

Therapeutic potential of tyrosine-protein kinase MET in osteosarcoma

Osteosarcoma, the most prevalent primary bone tumor in children and young adults, can often be successfully treated with standard chemotherapy and surgery when diagnosed at an early stage. However, patients presenting with metastases face significant challenges in achieving a cure. Despite advancements in classical therapies over the past few decades, clinical outcomes for osteosarcoma have not substantially improved. Recently, there has been increased understanding of the biology of osteosarcoma, leading to the identification of new therapeutic targets. One such target is MET, a tyrosine kinase receptor for Hepatocyte Growth Factor (HGF) encoded by the MET gene. In vitro and in vivo studies have demonstrated that the HGF/MET pathway plays a crucial role in cancer growth, invasion, metastasis, and drug resistance across various cancers. Clinical trials targeting this pathway are already underway for lung cancer and hepatocellular carcinoma. Moreover, MET has also been implicated in promoting osteosarcoma progression. This review summarizes 3 decades' worth of research on MET's involvement in osteosarcoma and further explores its potential as a therapeutic target for patients with this disease.

Leveraging spatial omics for the development of precision sarcoma treatments

Sarcomas are rare and heterogeneous cancers that arise from bone or soft tissue, and are the second most prevalent solid cancer in children and adolescents. Owing to the complex nature of pediatric sarcomas, the development of therapeutics for pediatric sarcoma has seen little progress in the past decades. Existing treatments are largely limited to chemotherapy, radiation, and surgery. Limited knowledge of the sarcoma tumor microenvironment (TME) and of well-defined target antigens in the different subtypes necessitates an alternative investigative approach to improve treatments. Recent advances in spatial omics technologies have enabled a more comprehensive study of the TME in multiple cancers. In this opinion article we discuss advances in our understanding of the TME of some cancers enabled by spatial omics technologies, and we explore how these technologies might advance the development of precision treatments for sarcoma, especially pediatric sarcoma.

Primary Multi-Systemic Metastases in Osteosarcoma: Presentation, Treatment, and Survival of 83 Patients of the Cooperative Osteosarcoma Study Group

BACKGROUND

To evaluate patient and tumour characteristics, treatment, and their impact on survival in patients with multi-systemic metastases at initial diagnosis of high-grade osteosarcoma. Precedure: Eighty-three consecutive patients who presented with multi-systemic metastases at initial diagnosis of high-grade osteosarcoma were retrospectively reviewed. In cases of curative intent, the Cooperative Osteosarcoma Study Group recommended surgical removal of all detectable metastases in addition to complete resection of the primary tumour and chemotherapy.

RESULTS

Eighty-three eligible patients (1.8%) were identified among a total of 4605 individuals with high-grade osteosarcoma. Nine (10.8%) of these achieved complete surgical remission, of whom seven later had recurrences. The median follow-up time was 12 (range, 1-165) months for all patients. Actuarial event-free survival after 1, 2, and 5 years was 9.6 ± 3.2%, 1.4 ± 1.4%, and 1.4 ± 1.4%, and overall survival was 54.0 ± 5.6%, 23.2 ± 4.9%, and 8.7 ± 3.3%. In univariate analyses, elevated alkaline phosphatase before chemotherapy, pleural effusion, distant bones as metastatic sites, and more than one bone metastasis were negative prognostic factors. Among treatment-related factors, the microscopically complete resection of the primary tumour, a good response to first-line chemotherapy, the macroscopically complete resection of all affected tumour sites, and local treatment (surgery ± radiotherapy) of all bone metastases were associated with better outcomes. Tumour progression under first-line treatment significantly correlated with shorter survival times.

CONCLUSION

The outlook for patients with multi-systemic primary metastases from osteosarcoma remains very poor. The utmost importance of surgical resection of all tumour sites was confirmed. For unresectable bone metastases, radiotherapy might be considered. In the patient group studied, standard chemotherapy was often insufficiently effective. In the case of such advanced disease, alternative treatment options are urgently required.

The function and mechanism of PSMD14 in promoting progression and resistance to anlotinib in osteosarcoma

BACKGROUND

Osteosarcoma is a rare bone malignancy that frequently affects adolescents and poses formidable obstacles in its advanced stages. Studies revealed that PSMD14 may be a viable osteosarcoma treatment target. However, PSMD14's function and mechanism in osteosarcoma remain unknown. This study aimed to examine the function and mechanism of PSMD14 in the biological behavior of osteosarcoma and its role in anlotinib resistance.

METHODS

Western blotting, qRT-PCR, and immunohistochemistry (IHC) studies were used to examine PSMD14 levels. The role of PSMD14 in the malignant phenotype of osteosarcoma and its molecular pathway was explored by a series of studies, including Western blotting, cell amplification assay, transwell assay, and tumor growth. Furthermore, a series of in vitro investigations were done to determine the effect of PSMD14 on anlotinib-resistant osteosarcoma cell lines.

RESULTS

PSMD14 expression was elevated in osteosarcoma tissues compared to normal tissues. Overexpression of PSMD14 was associated with osteosarcoma patients' pathological grade and clinical stage, and PSMD14 was an independent poor prognostic factor. PSMD14 knockdown inhibits in vitro cell proliferation, migration, invasion, and in vivo tumor growth. PSMD14 knockdown has the potential to downregulate the PI3K/Akt/mTOR pathway, which was regarded as one of the key mechanisms promoting tumor growth. PSMD14 was likewise overexpressed in anlotinib-resistant OS cell lines, and its knockdown not only reduced the proliferation, migration, and invasion of subline cells and triggered cell apoptosis. Importantly, combination therapy with anlotinib enhanced these effects.

CONCLUSIONS

PSMD14 is substantially expressed in osteosarcoma and may be an independent risk factor associated with poor prognosis. It can promote tumor progression and anlotinib resistance in osteosarcoma and may promote osteosarcoma progression by modulating PI3K/AKT/mTOR signaling pathway.

Regorafenib in patients with advanced Ewing sarcoma: results of a non-comparative, randomised, double-blind, placebo-controlled, multicentre Phase II study

BACKGROUND

The REGOBONE multi-cohort study explored the efficacy and safety of regorafenib for patients with advanced bone sarcomas; this report details the Ewing sarcoma (ES) cohort.

METHODS

Patients with relapsed ES progressing despite prior standard therapy, were randomised (2:1) to receive regorafenib or placebo. Patients on placebo could crossover to receive regorafenib after centrally confirmed progression. The primary endpoint was the progression-free rate at 8 weeks. With one-sided α of 0.05, and 80% power, at least 14/24 progression-free patients at 8 weeks were needed for success.

RESULTS

From September 2014 to November 2019, 41 patients were accrued. 36 patients were evaluable for efficacy: 23 on regorafenib and 13 on placebo. Thirteen patients (56%; one-sided 95% CI [37.5%-[)) were progression-free at 8 weeks on regorafenib vs. 1 (7.7%; 95% CI [0.4%-[) on placebo. Median PFS was 11.4 weeks on regorafenib, and 3.9 weeks on placebo. Ten placebo patients crossed over to receive regorafenib after progression. The most common grade ≥3 regorafenib-related adverse events were pain (22%), asthenia (17%), thrombocytopenia (13%) and diarrhoea (13%).

CONCLUSION

Although the primary endpoint was not met statistically in this randomised cohort, there is evidence to suggest that regorafenib might modestly delay tumour progression in relapsed ES after failure of prior chemotherapy.

Does primary tumor resection improve survival for patients with sarcomas of pelvic bones, sacrum, and coccyx who have metastasis at diagnosis ?

BACKGROUND

Recent studies demonstrated that primary tumor resection (PTR) improves survival of patients with metastatic bone sarcomas. However, it remains quite unclear regarding the role of PTR in the treatment of sarcomas of pelvic bones with synchronous metastasis at diagnosis.

METHODS

Using the Surveillance, Epidemiology, and End Results Program, we enrolled a total of 385 patients with sarcomas of pelvic bones, sacrum, and coccyx who have metastasis at initial diagnosis, including 139 patients with osteosarcoma, 176 with Ewing sarcoma, and 70 with chondrosarcoma. Association between PTR and disease-specific survival (DSS) were investigated using the univariable and multivariable Cox regression models. Hazard ratio (HR) and 95% confidence interval (CI) were reported. Representative institutional PTR strategies and clinical outcomes for patients with metastatic pelvic sarcomas from our cancer center were displayed.

RESULTS

The usage rate of PTR was 28.1% (39/139) in osteosarcoma, 13.6% (24/176) in Ewing sarcoma, and 41.4% (29/70) in chondrosarcoma with synchronous metastatic lesions. PTR was not associated with an improved DSS for metastatic pelvic osteosarcoma (HR = 0.686, 95% CI = 0.430 ~ 1.094, P = 0.113) and Ewing sarcoma (HR = 0.580, 95% CI = 0.291 ~ 1.154, P = 0.121). The use of PTR was associated with an improved DSS for metastatic pelvic chondrosarcoma (HR = 0.464, 95% CI = 0.225 ~ 0.954, P = 0.037).

CONCLUSION

Primary lesion resection may provide a survival benefit for metastatic chondrosarcoma, but not for osteosarcoma and Ewing sarcoma of pelvic bones, sacrum, and coccyx. This population-based study recommends an active surgical intervention for metastatic chondrosarcoma while non-surgical treatment for metastatic osteosarcoma and Ewing sarcoma of the pelvis in terms of survival improvement.

Phase 1 study of cabozantinib in combination with topotecan-cyclophosphamide for patients with relapsed Ewing sarcoma or osteosarcoma

PURPOSE

Phase 1 study assessing the safety and toxicity of cabozantinib in combination with topotecan and cyclophosphamide for relapsed osteosarcoma and Ewing sarcoma.

METHODS

Oral cabozantinib (25 mg/m2 ) was administered daily for 21 (dose level 1) or 14 (dose level -1B) days. Topotecan (0.75 mg/m2 ) and cyclophosphamide (250 mg/m2 ) were administered intravenously (IV) on days 1-5. A modified 3+3 design based upon first cycle dose-limiting toxicities (DLT) was used for dose escalation.

RESULTS

Twelve patients with a median age of 15 (12.9-33.2) years were enrolled (seven with Ewing sarcoma; five with osteosarcoma); all were evaluable for toxicity. At dose level 1, three of six patients developed first cycle DLT: grade 3 epistaxis, grade 3 transaminitis, and prolonged grade 2 thrombocytopenia. Six patients were enrolled on dose level -1B (interrupted cabozantinib, given days 8-21), with one first cycle DLT (grade 3 pneumothorax) observed. Of the 10 response evaluable patients, one had partial response (Ewing sarcoma), seven had stable disease, and two had progressive disease.

CONCLUSIONS

The recommended phase 2 doses and schedules for this combination are topotecan 0.75 mg/m2 IV days 1-5, cyclophosphamide 250 mg/m2 IV days 1-5, and cabozantinib 25 mg/m2 days 8-21. Non-concomitant administration of cabozantinib with cytotoxic therapy in this population has acceptable toxicity, while allowing for potential disease control.

Tyrosine kinase inhibitors in osteosarcoma: Adapting treatment strategiesa

Osteosarcoma (OS) is an aggressive primary bone malignancy that metastasizes rapidly. The standard of care has changed little over the previous four decades, and survival rates have plateaued. In this context, tyrosine kinase inhibitors (TKIs) emerge as potential treatments. A literature search was conducted to collect data related to receptor tyrosine kinase genetic alterations and expression in OS specimens. Gene amplification and protein expression of these receptors were linked to prognosis and tumor behavior. Relevant TKIs were evaluated as monotherapies and as parts of combination therapies. Certain TKIs, such as apatinib, regorafenib, and cabozantinib, present a potential therapeutic avenue for OS patients, especially when combined with chemotherapy. Producing long-lasting responses and enhancing quality of life remain key goals in OS treatment. To this effect, optimizing the use of TKIs by identifying biomarkers predictive of response and assessing promising TKIs in larger-scale trials to validate the efficacy and safety outcomes relative to these drugs reported in phase II clinical trials. To this effect, it is necessary to identify biomarkers predictive of response to TKIs in larger-scale trials and to validate the efficacy and safety of these drugs reported in phase II clinical trials.

A pilot study of multi-antigen stimulated cell therapy-I plus camrelizumab and apatinib in patients with advanced bone and soft-tissue sarcomas

BACKGROUND

Cell-based  immunotherapy shows the therapeutic potential in sarcomas, in addition to angiogenesis-targeted tyrosine kinase inhibitor (TKI) and immune checkpoint inhibitor (ICI). Multi-antigen stimulated cell therapy-I (MASCT-I) technology is a sequential immune cell therapy for cancer, which composes of multiple antigen-loaded dendritic cell (DC) vaccines followed by the adoptive transfer of anti-tumor effector T-cells.

METHODS

In this phase 1 study, we assessed MASCT-I plus camrelizumab (an ICI against PD-1) and apatinib (a highly selective TKI targeting VEGFR2) in patients with unresectable recurrent or metastatic bone and soft-tissue sarcoma after at least one line of prior systemic therapy. One MASCT-I course consisted of 3 DC subcutaneous injections, followed by 3 active T cell infusions administered 18-27 days after each DC injection. In schedule-I group, 3 DC injections were administered with a 28-day interval in all courses; in schedule-II group, 3 DC injections were administered with a 7-day interval in the first course and with a 28-day interval thereafter. All patients received intravenous camrelizumab 200 mg every 3 weeks and oral apatinib 250 mg daily.

RESULTS

From October 30, 2019, to August 12, 2021, 19 patients were enrolled and randomly assigned to schedule-I group (n = 9) and schedule-II group (n = 10). Of the 19 patients, 11 (57.9%) experienced grade 3 or 4 treatment-related adverse events. No treatment-related deaths occurred. Patients in schedule-II group showed similar objective response rate (ORR) with those in schedule-I group (30.0% versus 33.3%) but had higher disease control rate (DCR; 90.0% versus 44.4%) and longer median progression-free survival (PFS; 7.7 versus 4.0 months). For the 13 patients with soft-tissue sarcomas, the ORR was 30.8%, DCR was 76.9%, and median PFS was 12.9 months; for the 6 patients with osteosarcomas, the ORR was 33.3%, the DCR was 50.0%, and median PFS was 5.7 months.

CONCLUSIONS

Overall, MASCT-I plus camrelizumab and apatinib was safe and showed encouraging efficacy in advanced bone and soft-tissue sarcoma, and schedule-II administration method was recommended.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT04074564.

Long non-coding RNA GAS5 promotes cisplatin-chemosensitivity of osteosarcoma cells via microRNA-26b-5p/TP53INP1 axis

Osteosarcoma is a common malignant bone tumor. Cisplatin (DDP) achieves a high response rate in osteosarcoma. Here we aim to study the dysregulation of long non-coding RNA the growth arrest-specific transcript 5 (GAS5), and its roles in DDP-resistance of osteosarcoma. The expression of mRNA and microRNA in osteosarcoma tissues and osteosarcoma cell lines were detected by quantitative reverse-transcription polymerase chain reaction, and protein expression levels were measured by western blotting assay. Cell Counting Kit-8 and 5-Ethynyl-2'-deoxyuridine were used to measure cell proliferation. Flow cytometer assay was used to evaluate cell apoptosis. The interactions between miR-26b-5p and GAS5 or tumor protein p53-induced nuclear protein 1 (TP53INP1) were verified by dual luciferase reporter along with biotin RNA pull-down assays. GAS5 was identified to be significantly lowly expressed in osteosarcoma samples especially in cisplatin-resistant (DDP-resistant) tissues. GAS5 was also downregulated in DDP-resistant cells. Over-expressed GAS5 prominently increased the sensitivity of osteosarcoma cells to DDP in vitro. Furthermore, over-expression of GAS5 suppressed cell proliferation and facilitated apoptosis of DDP-resistant cells. Mechanistically, GAS5 sponged miR-26b-5p, over-expression of which reversed the effects of GAS5 on cell proliferation and apoptosis of DDP-resistant cells. In addition, miR-26b-5p targeted TP53INP1. TP53INP1 abrogated the functions of miR-26b-5p on cell proliferation and apoptosis in DDP-resistant cells. Taken together, GAS5 enhanced the sensitivity of osteosarcoma cells to DDP via GAS5/miR-26b-5p/TP53INP1 axis. Therefore, GAS5 may be a potential indicator for the management of osteosarcoma.

Prognosis of limb‑salvage treatment of osteosarcoma in adolescent patients: a meta‑analysis

To evaluate the effectiveness of limb-salvage treatment for osteosarcoma in adolescent patients, a comprehensive search on PubMed, Embase and Cochrane Library was conducted. Studies with a clear diagnosis of osteosarcoma were included and duplicate publications, studies without full text or incomplete information, those with an inability to extract data, divergent definitions of exposure, animal experiments, reviews, and systematic reviews were excluded. The data were analyzed using STATA 15.1. The findings of the present study revealed that overall survival (OS) and progression-free survival (PFS) of patients with osteosarcoma in the limb-salvage treatment group were significantly longer than those in the amputation treatment group [hazard ratio (HR)=0.71; 95% confidence interval (CI): 0.63-0.80; P=0.000 vs. HR=0.60; 95% CI: 0.48-0.76; P=0.000]. Additionally, the five-year OS rate for patients in the limb-salvage treatment group was higher than that in the amputation group [odds ratio (OR)=4.48; 95% CI: 2.74-7.31; P=0.000]. However, the local recurrence rate was notably higher in the limb-salvage treatment group compared with the amputation treatment group (OR=2.68; 95% CI: 1.50-4.77; P=0.001). Furthermore, the results indicated no significant difference in distant metastasis rates between the limb-salvage treatment group and the amputation treatment group (OR=0.32; 95% CI: 0.10-1.06; P=0.062). In conclusion, the present meta-analysis underscores the potential of limb-salvage therapy for adolescent patients with osteosarcoma. The OS and PFS of patients undergoing limb-salvage surgery are longer than those of amputation, with a higher five-year OS rate and a similar rate of distant metastasis. However, the local recurrence rate of limb-salvage surgery is significantly higher than that of amputation.

A systematic review of recent phase-II trials in refractory or recurrent osteosarcoma: Can we inform future trial design?

BACKGROUND/OBJECTIVE

To analyze changes in recurrent/refractory osteosarcoma phase II trials over time to inform future trials in this population with poor prognosis.

METHODS

A systematic review of trials registered on trial registries between 01/01/2017-14/02/2022. Comparison of 98 trials identified between 2003 and 2016. Publication search/analysis for both periods, last update on 01/12/2022.

RESULTS

Between 2017 and 2022, 71 phase-II trials met our selection criteria (19 osteosarcoma-specific trials, 14 solid tumor trials with and 38 trials without an osteosarcoma-specific stratum). The trial number increased over time: 13.9 versus 7 trials/year (p = 0.06). Monotherapy remained the predominant treatment (62% vs. 62%, p = 1). Targeted therapies were increasingly evaluated (66% vs. 41%, P = 0.001). Heterogeneity persisted in the trial characteristics. The inclusion criteria were measurable disease (75%), evaluable disease (14%), and surgical remission (11%). 82% of the trials included pediatric or adolescent patients. Biomarker-driven trials accounted for 25% of the total trials. The survival endpoint use (rather than response) slightly increased (40% versus 31%), but the study H1/H0 hypotheses remained heterogeneous. Single-arm designs predominated over multiarm trials (n = 7). Available efficacy data on 1361 osteosarcoma patients in 58 trials remained disappointing, even though 21% of these trials were considered positive, predominantly those evaluating multi-targeted kinase inhibitors.

CONCLUSION

Despite observed changes in trial design and an increased number of trials investigating new therapies, high heterogeneity remained with respect to patient selection, study design, primary endpoints, and statistical hypotheses in recently registered phase II trials for osteosarcoma. Continued optimization of trial design informed by a deeper biological understanding should strengthen the development of new therapies.

Evaluation of prevalence and outcomes of serial tyrosine kinase inhibitor use in pediatric patients with advanced solid tumors

PURPOSE

Multitargeted tyrosine kinase inhibitors (mTKIs) are increasingly utilized in the treatment of pediatric sarcomas and other solid tumors. It is unknown whether serial treatment with multiple TKIs provides a benefit and which patients are most likely to benefit from mTKI rechallenge.

METHODS

We performed a retrospective cohort study of pediatric cancer patients who received serial mTKI therapy off-study between 2007 and 2020 as either monotherapy or combination therapy. We report patient characteristics, clinical outcomes, dosing patterns, and treatment-associated toxicity.

RESULTS

The study cohort included 25 patients. The overall prevalence of serial mTKI therapy among all patients treated for sarcoma at our institution was 3.7%, and the response rate to second mTKI was 9%. Median 6-month progression-free survival (PFS) and overall survival (OS) from start of second mTKI were 42.1% (95% CI: 20.4%-62.5%) and 79.1% (95% CI: 57.0%-90.8%), respectively. Patients who had received 4 months or more (n = 11) of therapy with first mTKI had significantly longer PFS versus those who received less than 4 months (n = 11; p = .001). Thirty-three percent of patients discontinued second mTKI due to toxicity. Six (40%) of 15 patients who discontinued the first mTKI due to progression had either a partial response or stable disease on the second mTKI.

CONCLUSIONS

We observed a low response rate to mTKI rechallenge. However, we identified patients who had been treated with first mTKI for  ≥4 months as more likely to have prolonged stable disease with second mTKI. Several patients had a response or stable disease on the second mTKI despite having progressed on the first mTKI. Though toxicity was common, only a minority of patients discontinued the second mTKI due to toxicity.

Network pharmacology and experimental verification-based strategy for exploring the mechanisms of luteolin in the treatment of osteosarcoma

BACKGROUND

Luteolin is an active ingredient in various traditional Chinese medicines for the treatment of multiple tumors. However, the mechanisms of its inhibitory effect on osteosarcoma proliferation and metastasis remain unclear.

PURPOSE

To elucidate the anti-osteosarcoma mechanisms of luteolin based on network pharmacology and experimental verification.

STUDY DESIGN

Integrate network pharmacology predictions, scRNA-seq analysis, molecular docking, and experimental validation.

METHODS

Luteolin-related targets and osteosarcoma-associated targets were collected from several public databases. The luteolin against osteosarcoma targets were screened and a PPI network was constructed to identify the hub targets. The GO and KEGG enrichment of osteosarcoma-associated targets and luteolin against osteosarcoma targets were performed. And scRNA-seq analysis was performed to determine the distribution of the core target expression in OS tissues. Molecular docking, cell biological assays, and osteosarcoma orthotopic mouse model was performed to validate the inhibitory effect and mechanisms of luteolin on osteosarcoma proliferation and metastasis.

RESULTS

Network pharmacology showed that 251 luteolin against osteosarcoma targets and 8 hub targets including AKT1, ALB, CASP3, IL6, JUN, STAT3, TNF, and VEGFA, and the PI3K-AKT signaling pathway might play an important role in anti-osteosarcoma of luteolin. Analysis of public data revealed that AKT1, IL6, JUN, STAT3, TNF, and VEGFA expression in OS tissue was significantly higher than that in normal bones, and the diagnostic value of VEGFA for overall survival and metastasis was increased over time. scRNA-seq analysis revealed significantly higher expression of AKT1, STAT3, and VEGFA in MYC+ osteoblastic OS cells, especially in primary samples. Moreover, the docking activity between luteolin and the hub targets was excellent, as verified by molecular docking. Experimental results showed that luteolin could inhibit cell viability and significantly decrease the expression of AKT1, STAT3, IL6, TNF, and VEGFA, and luteolin could also inhibit osteosarcoma proliferation and metastasis in osteosarcoma orthotopic mouse model.

CONCLUSION

This study shows that luteolin may regulate multiple signaling pathways by targeting various genes like AKT1, STAT3, IL6, TNF, and VEGFA to inhibit osteosarcoma proliferation and metastasis.

Special Issue: "Pediatric Orthopedic Malignancy: Types, Symptoms, and Treatment"

Pediatric orthopedic malignancies are extremely rare and require appropriate diagnosis and treatment by a multidisciplinary team [...].

Antitumor Effects of β-Elemene Through Inducing Autophagy-Mediated Apoptosis in Ewing Sarcoma Family Tumor Cells

Ewing sarcoma family tumors (ESFTs) are a group of aggressive tumors mainly affecting children and young people. A compound derived from Curcuma wenyujin plant or lemon grass, β-elemene, has exhibited antitumor effects to ESFT cells, the mechanism of which remains to be clarified further. Autophagy is involved in the antitumor effects of various drugs, whereas the role of autophagy in the antitumor effects of β-elemene persists controversial. Herein we found that β-elemene treatment inhibited the viability of ESFT cells in a dose-dependent manner. The increase of LC3-II level and the decrease of p62 level were observed in β-elemene-treated cells, as well as the increase of autolysosomes, which indicated the promotion of autophagic flux. Sequentially the autophagy inhibition using 3-MA treatment or ATG5 depletion significantly reversed the viability repression and apoptosis induction by β-elemene treatment. In addition, autophagy was found to be important in the toxic effects induced by the combination treatment of β-elemene and IGF1R inhibition in ESFT cells. Our data suggested an essential role of autophagy in β-elemene-induced apoptosis in ESFT cells, which is anticipated to provide novel insights to the development of ESFT treatments.

Real-world experience of tyrosine kinase inhibitors in children, adolescents and adults with relapsed or refractory bone tumours: A Canadian Sarcoma Research and Clinical Collaboration (CanSaRCC) study

OBJECTIVES

We conducted a retrospective multi-centre study to assess the real-world outcome of regorafenib (REGO) and cabozantinib (CABO) in recurrent/refractory bone tumours (BTs) including osteosarcoma (OST), Ewing sarcoma (EWS) and chondrosarcoma (CS)/extra-skeletal mesenchymal CS (ESMC).

METHODS

After regulatory approval, data from patients with recurrent BT (11 institutions) were extracted from CanSaRCC (Canadian Sarcoma Research and Clinical Collaboration) database. Patient characteristics, treatment and outcomes were collected. Progression-free survival (PFS) and overall survival (OS) were estimated using the Kaplan-Meier method.

RESULTS

From July 2018 to May 2022, 66 patients received REGO or CABO; 39 OST, 18 EWS, 4 CS and 5 ESMC. Median age was 27.8 years (range 12-76); median starting dose was 60 mg for CABO (n = 37, range 40-60) and 120 mg for REGO (n = 29, range 40-160). Twenty-eight (42.4%) patients required dose reduction: hand-foot syndrome 7 (10.6%), nausea/vomiting 1 (1.5%), diarrhoea 1 (1.5%), 2 elevated LFTs (3%), elevated bilirubin 1 (1.5%) and mucositis 1 (1.5%). The median OS for patients with OST, EWS, CS and ESMC was 8.5 months (n = 39, 95% CI 7-13.1); 13.4 months (n = 18, 95% CI 3.4-27.2), 8.1 (n = 4, 95% CI 4.1-9.3) and 18.2 (n = 5, 95% CI (10.4-na), respectively. Median PFS for OST, EWS, CS and ECMS was 3.5 (n = 39, 95% CI 2.8-5), 3.9 (n = 18, 95% CI 2.1-5.9), 5.53 (n = 4. 95% CI 2.13-NA) and 11.4 (n = 5, 95% CI 1.83-14.7), respectively. Age, line of therapy, REGO versus CABO, or time from diagnosis to initiation of TKI were not associated with PFS on univariable analysis.

CONCLUSION

Our real-world data show that TKIs have meaningful activity in recurrent BT with acceptable toxicities when started at modified dosing. Inclusion of TKIs in earlier lines of treatment and/or maintenance therapy could be questions for future research.

Current topics and management of head and neck sarcomas

Given the low incidence, variety of histological types, and heterogeneous biological features of head and neck sarcomas, there is limited high-quality evidence available to head and neck oncologists. For resectable sarcomas, surgical resection followed by radiotherapy is the principle of local treatment, and perioperative chemotherapy is considered for chemotherapy-sensitive sarcomas. They often originate in anatomical border areas such as the skull base and mediastinum, and they require a multidisciplinary treatment approach considering functional and cosmetic impairment. Moreover, head and neck sarcomas may exhibit different behaviour and characteristics than sarcomas of other areas. In recent years, the molecular biological features of sarcomas have been used for the pathological diagnosis and development of novel agents. This review describes the historical background and recent topics that head and neck oncologists should know about this rare tumour from the following five perspectives: (i) epidemiology and general characteristics of head and neck sarcomas; (ii) changes in histopathological diagnosis in the genomic era; (iii) current standard treatment by histological type and clinical questions specific to head and neck; (iv) new drugs for advanced and metastatic soft tissue sarcomas; and (v) proton and carbon ion radiotherapy for head and neck sarcomas.

Targeting signaling pathways in osteosarcoma: Mechanisms and clinical studies

Osteosarcoma (OS) is a highly prevalent bone malignancy among adolescents, accounting for 40% of all primary malignant bone tumors. Neoadjuvant chemotherapy combined with limb-preserving surgery has effectively reduced patient disability and mortality, but pulmonary metastases and OS cells' resistance to chemotherapeutic agents are pressing challenges in the clinical management of OS. There has been an urgent need to identify new biomarkers for OS to develop specific targeted therapies. Recently, the continued advancements in genomic analysis have contributed to the identification of clinically significant molecular biomarkers for diagnosing OS, acting as therapeutic targets, and predicting prognosis. Additionally, the contemporary molecular classifications have revealed that the signaling pathways, including Wnt/β-catenin, PI3K/AKT/mTOR, JAK/STAT3, Hippo, Notch, PD-1/PD-L1, MAPK, and NF-κB, have an integral role in OS onset, progression, metastasis, and treatment response. These molecular classifications and biological markers have created new avenues for more accurate OS diagnosis and relevant treatment. We herein present a review of the recent findings for the modulatory role of signaling pathways as possible biological markers and treatment targets for OS. This review also discusses current OS therapeutic approaches, including signaling pathway-based therapies developed over the past decade. Additionally, the review covers the signaling targets involved in the curative effects of traditional Chinese medicines in the context of expression regulation of relevant genes and proteins through the signaling pathways to inhibit OS cell growth. These findings are expected to provide directions for integrating genomic, molecular, and clinical profiles to enhance OS diagnosis and treatment.

Kinome-wide CRISPR-Cas9 knockout screens revealed PLK1 as a therapeutic target for osteosarcoma

Osteosarcoma is the most common malignant bone tumor, tending to be aggressive and recurrent. The therapeutic development for treating osteosarcoma has been largely hampered by the lack of effective and specific targets. Using kinome-wide CRISPR-Cas9 knockout screens, we systematically revealed a cohort of kinases essential for the survival and growth of human osteosarcoma cells, in which Polo-like kinase 1 (PLK1) appeared as a specific prominent hit. PLK1 knockout substantially inhibited proliferation of osteosarcoma cells in vitro and the tumor growth of osteosarcoma xenograft in vivo. Volasertib, a potent experimental PLK1 inhibitor, can effectively inhibit the growth of the osteosarcoma cell lines in vitro. It can also disrupt the development of tumors in the patient-derived xenograft (PDX) models in vivo. Furthermore, we confirmed that the mode of action (MoA) of volasertib is primarily mediated by the cell-cycle arrest and apoptosis triggered by DNA damage. As PLK1 inhibitors are entering phase III clinical trials, our findings provide important insights into the efficacy and MoA of the relevant therapeutic approach for combating osteosarcoma.

The Diagnosis and Treatment of Osteosarcoma and Ewing's Sarcoma in Children and Adolescents

BACKGROUND

Osteosarcoma and Ewing's sarcoma in children and adolescents require age-specific interdisciplinary diagnosis and treatment to achieve optimal therapeutic outcomes.

METHODS

The diagnosis and treatment of malignant bone tumors in childhood and adolescence are presented in the light of publications retrieved by a selective search, pertinent guidelines, and the authors' extensive experience in an interdisciplinary cancer center.

RESULTS

Bone sarcomas make up approximately 5% of all malignancies in children and adolescents; the most common types are Ewing's sarcoma and osteosarcoma. Patients are often not referred to a specialized center until long after the onset of symptoms, as they and their physicians rarely consider the possibility of a bone tumor, and the symptoms are often trivialized. Bone pain of unknown origin, swelling, and functional limitations should be investigated with conventional x-rays. Lesions of unclear origin should be biopsied after a meticulous clinical and radiologic evaluation. Multimodal treatment consists of neo - adjuvant chemotherapy, limb-preserving resection if possible, and radiotherapy where indicated. In multicenter studies, patients with osteosarcoma achieve event-free survival in 64% of cases if their disease is localized, and 28% if it is metastatic; the corresponding figures for patients with Ewing's sarcoma are 80% and 27%, respectively.

CONCLUSION

With implementation of the current treatment recommendations, most children and adolescents with malignant bone tumors can be treated successfully with curative intent. These patients should be referred to a sarcoma center for diagnosis and treatment.

Modern treatment strategies in pediatric oncology and hematology

Every year, approximately 400 00 children worldwide are diagnosed with cancer. Although treatment results in most types of childhood neoplasms are excellent with survival more than 80%, there are some with poor prognosis. Also recurrent and resistant to treatment childhood cancer remain a therapeutic challenge. Besides chemotherapy, which has been the basis of cancer therapy for years, molecular methods and precisely targeted therapies have recently found their usage. As a result of that, survival has improved and has positively impacted the rate of toxicities associated with chemotherapy (Butler et al. in CA Cancer J Clin 71:315-332, 2021). These achievements have contributed to better quality of patients' lives. Current methods of treatment and ongoing trials give hope for patients with relapses and resistance to conventional chemotherapy. This review focuses on the most recent progress in pediatric oncology treatments and discusses specific therapy methods for particular cancers types of cancer. Targeted therapies and molecular approaches have become more beneficial but research need to be continued in this field. Despite significant breakthroughs in pediatric oncology in the last few years, there is still a need to find new and more specific methods of treatment to increase the survival of children with cancer.

A meta-analysis: the clinical value of PD-1 inhibitor or protein tyrosine kinase inhibitors in the treatment of advanced osteosarcoma

Backgrounds

PD-1 inhibitors and TKIs have been used to treat advanced osteosarcoma, but there is still a lack of intuitive data for the comparison of their efficacy. We conducted a meta-analysis to evaluate their therapeutic benefits.

Methods

A systematic methodological search of five primary electronic databases was performed. Studies with a randomized design of any type about PD-1 inhibitors or TKIs for the treatment of advanced osteosarcoma were included. The primary outcomes mainly included CBR, PFS, OS and ORR, The CR, PR, SD and AEs were the secondary outcomes. The survival period (months) of patients was taken as the main analysis data. Random-effects models were used for meta-analysis.

Results

Eight immunocheckpoint inhibitors in 327 patients from 10 clinical trials were finally evaluated. For OS, TKIs [11.67 months (95% CI, 9.32-14.01)] show more obvious advantages than PD-1 inhibitors [6.37 months (95% CI, 3.96-8.78)]. For PFS, TKIs [4.79 months (95% CI, 3.33-6.24)] are longer than PD-1 inhibitors [1.46 months (95% CI, 1.23-1.69)]. Although there was no fatal event, attention should still be paid, especially during the combined application of PD-1 inhibitors with TKIs since their obvious AEs.

Conclusions

The findings of this study suggest that patients with advanced osteosarcoma, TKIs may be more beneficial than PD-1 inhibitors. TKIs combined with PD-1 inhibitors has a bright future in the treatment of advanced osteosarcoma, but we should always pay attention to the strong side effects.

Safety profile of vascular endothelial growth factor receptor tyrosine-kinase inhibitors in pediatrics: a pharmacovigilance disproportionality analysis

Introduction: existing research on children consists primarily of phase I/II clinical trials for VEGFR-TKI. System reports of safety on the use of VEGFR-TKI in pediatrics are lacking. Aim: to investigate the safety profiles of VEGFR-TKI in pediatrics via the FDA Adverse Event Reporting System (FAERS). Method: data regarding VEGFR-TKIs were extracted from the FAERS between 2004Q1 to 2022Q3 and categorized by the Medical Dictionary for Regulatory Activities (MedDRA). Population characteristics were analyzed, and reporting odds ratio (ROR) was performed to identify risk signals associated with VEGFR-TKI. Results: 53,921 cases containing 561 children were identified in the database from 18 May 2005, to 30 September 2022. Among those in the system organ class, skin, subcutaneous tissue disorders, and blood and lymphatic system disorders in pediatrics contributed to over 140 cases. Palmar-plantar eythrodysesthesia syndrome (PPES) in VEGFR-TKI presented the most significant 340.9 (95% 229.2-507.0). And pneumothorax also gave a high reporting odds ratio of 48.9 (95% 34.7-68.9). For a specific drug, musculoskeletal pain gave a ROR of 78.5 (95% 24.4-252.6) in cabozantinib and oesophagitis in lenvatinib with a ROR of 95.2 (95% 29.5-306.9). Additionally, hypothyroidism presented a high signal, especially sunitinib, with a ROR of 107.8 (95% 37.6-308.7). Conclusion: the present study explored the safety profile of VEGFR-TKI in pediatrics using the FAERS database. Multiple skin and subcutaneous tissue disorders, as well as blood and lymphatic system disorders, were common VEGFR-TKI-related AEs in system organ class. No serious hepatobiliary AEs were detected. For the specific AEs, PPES and pneumothorax were VEGFR-TKI-related AEs that presented significantly higher signals than those in the general population.

Large retroperitoneal extraskeletal Ewing's sarcoma with renal pedicle invasion: a case report

BACKGROUND

Extraskeletal Ewing's sarcoma (EES) is a rare malignant tumor primarily found in children and young adults. Localized disease can present with nonspecific symptoms such as local mass, regional pain, and increased skin temperature. More severe cases may present with systemic symptoms such as malaise, weakness, fever, anemia, and weight loss. Among these lesions, retroperitoneal sarcomas are relatively uncommon and difficult to diagnose. Since they are usually asymptomatic until large enough to compress or invade the surrounding tissues, most are already advanced at first detection. Traditionally, the treatment of choice is complete surgical resection, sometimes combined with postoperative radiotherapy and chemotherapy. We report a case of EES with left renal artery invasion in the left retroperitoneal cavity successfully treated with transarterial embolization and surgery.

CASE PRESENTATION

A 57-year-old woman with a negative family history of cancer presented at our Urology Department with a large left retroperitoneal tumor found by magnetic resonance imaging during the health exam. Physical examination showed a soft abdomen and no palpable mass or tenderness. Imaging studies showed that the tumor covered the entire left renal pedicle, but the left kidney, left adrenal gland, and pancreas appeared tumor free. Since the tumor tightly covered the entire renal pedicle, tumor excision with radical nephrectomy was advised. The patient underwent transarterial embolization of the left renal artery with 10 mg of Gelfoam pieces daily before surgical excision. Tumor excision and left radical nephrectomy were uneventful the day after embolization. Post-operatively, the patient recovered well and was discharged on day 10. The final histopathological analysis showed a round blue cell tumor consistent with an Ewing sarcoma, and the surgical margins were tumor free.

CONCLUSIONS

Retroperitoneal malignancies are rare but usually severe conditions. Our case report showed that retroperitoneal EES with renal artery invasion could be treated safely with transarterial embolization and surgery.

Bad to the Bone: Emerging Approaches to Aggressive Bone Sarcomas

Bone sarcomas are rare heterogeneous tumors that affect patients of all ages including children, adolescent young adults, and older adults. They include many aggressive subtypes and patient groups with poor outcomes, poor access to clinical trials, and lack of defined standard therapeutic strategies. Conventional chondrosarcoma remains a surgical disease, with no defined role for cytotoxic therapy and no approved targeted systemic therapies. Here, we discuss promising novel targets and strategies undergoing evaluation in clinical trials. Multiagent chemotherapy has greatly improved outcomes for patients with Ewing sarcoma (ES) and osteosarcoma, but management of those with high-risk or recurrent disease remains challenging and controversial. We describe the impact of international collaborative trials, such as the rEECur study, that aim to define optimal treatment strategies for those with recurrent, refractory ES, and evidence for high-dose chemotherapy with stem-cell support. We also discuss current and emerging strategies for other small round cell sarcomas, such as CIC-rearranged, BCOR-rearranged tumors, and the evaluation of emerging novel therapeutics and trial designs that may offer a new paradigm to improve survival in these aggressive tumors with notoriously bad (to the bone) outcomes.

Roles of TGF-β signals in tumor microenvironment via regulation of the formation and plasticity of vascular system

Tumor cells evolve in tumor microenvironment composed of multiple cell types. Among these, endothelial cells (ECs) are the major players in tumor angiogenesis, which is a driver of tumor progression and metastasis. Increasing evidence suggests that ECs also contribute to tumor progression and metastasis as they modify their phenotypes to differentiate into mesenchymal cells through a process known as endothelial-mesenchymal transition (EndoMT). This plasticity of ECs is mediated by various cytokines, including transforming growth factor-β (TGF-β), and modulated by other stimuli depending on the cellular contexts. Recent lines of evidence have shown that EndoMT is involved in various steps of tumor progression, including tumor angiogenesis, intravasation and extravasation of cancer cells, formation of cancer-associated fibroblasts, and cancer therapy resistance. In this review, we summarize current updates on EndoMT, highlight the roles of EndoMT in tumor progression and metastasis, and underline targeting EndoMT as a potential therapeutic strategy.

Osteosarcoma: Current Concepts and Evolutions in Management Principles

Osteosarcoma is a rare malignancy arising from mesenchymal tissue, and represents the most common bone sarcoma. The management of osteosarcoma is challenging, and requires a multidisciplinary approach. In daily clinical practice, surgery, radiotherapy, and conventional chemotherapy constitute the therapeutic armamentarium against the disease. However, a significant number of patients with initially localized osteosarcoma will experience local or distant recurrence, and the prognosis for metastatic disease remains dismal. There is a pressing need to identify novel therapeutic strategies to better manage osteosarcoma and improve survival outcomes. In this study, we present recent advances in the therapeutic management of osteosarcoma, including surgical and medical advances. The role of immunotherapy (immune checkpoint inhibitors, adoptive cellular therapy, cancer vaccines) and other targeted therapies including tyrosine kinase inhibitors is discussed; however, additional studies are required to delineate their roles in clinical practice.

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.

The Use of Hydrogels for the Treatment of Bone Osteosarcoma via Localized Drug-Delivery and Tissue Regeneration: A Narrative Review

Osteosarcoma is a malignant tumor of bone that leads to poor mortality and morbidity. Management of this cancer through conventional methods involves invasive treatment options that place patients at an increased risk of adverse events. The use of hydrogels to target osteosarcoma has shown promising results both in vitro and in vivo to eradicate tumor cells while promoting bone regeneration. The loading of hydrogels with chemotherapeutic drugs provides a route for site-specific targeted therapy for osteosarcoma. Current studies demonstrate tumor regression in vivo and lysis of tumor cells in vitro when exposed to doped hydrogel scaffolds. Additionally, novel stimuli-responsive hydrogels are able to react with the tissue microenvironment to facilitate the controlled release of anti-tumor drugs and with biomechanical properties that can be modulated. This narrative review of the current literature discusses both in vitro and in vivo studies of different hydrogels, including stimuli-responsive, designed to treat bone osteosarcoma. Future applications to address patient treatment for this bone cancer are also discussed.

Receptor tyrosine kinase inhibitors in cancer

Targeted therapy is a new cancer treatment approach, involving drugs that particularly target specific proteins in cancer cells, such as receptor tyrosine kinases (RTKs) which are involved in promoting growth and proliferation, Therefore inhibiting these proteins could impede cancer progression. An understanding of RTKs and the relevant signaling cascades, has enabled the development of many targeted drug therapies employing RTK inhibitors (RTKIs) some of which have entered clinical application. Here we discuss RTK structures, activation mechanisms and functions. Moreover, we cover the potential effects of combination drug therapy (including chemotherapy or immunotherapy agents with one RTKI or multiple RTKIs) especially for drug resistant cancers.

Recent advances on anti-angiogenic multi-receptor tyrosine kinase inhibitors in osteosarcoma and Ewing sarcoma

Osteosarcoma (OS) and Ewing sarcoma (ES) are the two most common types of primary bone cancer that predominantly affect the young. Despite aggressive multimodal treatment, survival has not improved significantly over the past four decades. Clinical efficacy has historically been observed for some mono-Receptor Tyrosine Kinase (RTK) inhibitors, albeit in small subsets of OS and ES patients. Clinical efficacy in larger groups of OS or ES patients was reported recently with several newer generation multi-RTK inhibitors. All these inhibitors combine a strong anti-angiogenic (VEGFRs) component with simultaneous inhibition of other key RTKs implicated in OS and ES progression (PDGFR, FGFR, KIT and/or MET). However, despite interesting clinical data, none of these agents have obtained a registration for these indications and are thus difficult to implement in routine OS and ES patient care. It is at present also unclear which of these drugs, with largely overlapping molecular inhibition profiles, would work best for which patient or subtype, and treatment resistance almost uniformly occurs. Here, we provide a critical assessment and systemic comparison on the clinical outcomes to the six most tested drugs in this field in OS and ES to date, including pazopanib, sorafenib, regorafenib, anlotinib, lenvatinib and cabozantinib. We pay special attention to clinical response evaluations in bone sarcomas and provide drug comparisons, including drug-related toxicity, to put these drugs into context for OS and ES patients, and describe how future trials utilizing anti-angiogenic multi-RTK targeted drugs could be designed to ultimately improve response rates and decrease toxicity.

The Next Frontier in Sarcoma: Molecular Pathways and Associated Targeted Therapies

Soft tissue sarcomas (STS) are a rare, complex, heterogeneous group of mesenchymal neoplasms with over 150 different histological subtypes. Treatments for this malignancy have been especially challenging due to the heterogeneity of the disease and the modest efficacy of conventional chemotherapy. The next frontier lies in discerning the molecular pathways in which these mesenchymal neoplasms arise, metastasize, and develop drug-resistance, thereby helping guide new therapeutic targets for the treatment of STS. This comprehensive review will discuss the current understanding of tumorigenesis of specific STS subtypes, including oncogenic pathway alterations involved in cell cycle regulation, angiogenesis, NOTCH signaling, and aberrant genetic rearrangements. It will then review current therapies that have been recently developed to target these pathways, including a review of ongoing clinical studies for targeted sarcoma treatment, as well as discuss new potential avenues for therapies against known molecular pathways of sarcomagenesis.

Targeted therapy for osteosarcoma: a review

BACKGROUND

Osteosarcoma is a common primary malignant tumour of the bone that usually occurs in children and adolescents. It is characterised by difficult treatment, recurrence and metastasis, and poor prognosis. Currently, the treatment of osteosarcoma is mainly based on surgery and auxiliary chemotherapy. However, for recurrent and some primary osteosarcoma cases, owing to the rapid progression of disease and chemotherapy resistance, the effects of chemotherapy are poor. With the rapid development of tumour-targeted therapy, molecular-targeted therapy for osteosarcoma has shown promise.

PURPOSE

In this paper, we review the molecular mechanisms, related targets, and clinical applications of targeted osteosarcoma therapy. In doing this, we provide a summary of recent literature on the characteristics of targeted osteosarcoma therapy, the advantages of its clinical application, and development of targeted therapy in future. We aim to provide new insights into the treatment of osteosarcoma.

CONCLUSION

Targeted therapy shows potential in the treatment of osteosarcoma and may offer an important means of precise and personalised treatment in the future, but drug resistance and adverse effects may limit its application.

Real-World Data on Cabozantinib in Advanced Osteosarcoma and Ewing Sarcoma Patients: A Study from the Hellenic Group of Sarcoma and Rare Cancers

Advanced osteosarcomas (OSs) and Ewing sarcomas (ESs) tend to have poor prognosis with limited therapeutic options beyond first-line therapy. Aberrant angiogenesis and MET signaling play an important role in preclinical models. The anti-angiogenic drug cabozantinib was tested in a phase 2 trial of advanced OS and ES and was associated with clinical benefits. We retrospectively analyzed the off-label use of cabozantinib in adult patients with advanced OS and ES/primitive neuroectodermal tumors (PNETs) in three centers of the Hellenic Group of Sarcoma and Rare Cancers (HGSRC). Between April 2019 and January 2022, 16 patients started taking 60 mg of cabozantinib for advanced bone sarcoma or PNET. Median age at cabozantinib initiation was 31 years (17-83). All patients had received peri-operative chemotherapy for primary sarcoma and between 0 and 4 lines of treatment (median; 2.5) for advanced disease. The most common adverse effects included fatigue, anorexia, hypertransaminasemia, weight loss, and diarrhea. One toxic death was noted (cerebral hemorrhage). Dose reduction to 40 mg was required in 31.3% of the patients. No objective response was noted, and 9/16 patients exhibited stable disease outcomes. Progression-free survival varied from 1 to 8 (median; 5) months. Our study demonstrates that cabozantinib has antitumor activity in this population. In the real-life setting, we observed similar adverse events as in the CABONE study and in other neoplasms.

Targeted treatment of solid tumors in pediatric precision oncology

The treatment of childhood solid cancer has markedly evolved in recent years following a refined molecular characterization and the introduction of novel targeted drugs. On one hand, larger sequencing studies have revealed a spectrum of mutations in pediatric tumors different from adults. On the other hand, specific mutations or immune dysregulated pathways have been targeted in preclinical and clinical studies, with heterogeneous results. Of note, the development of national platforms for tumor molecular profiling and, in less measure, for targeted treatment, has been essential in the process. However, many of the available molecules have been tested only in relapsed or refractory patients, and have proven poorly effective, at least in monotherapy. Our future approaches should certainly aim at improving the access to molecular characterization, to obtain a deeper picture of the distinctive phenotype of childhood cancer. In parallel, the implementation of access to novel drugs should not only be limited to basket or umbrella studies but also to larger, multi-drug international studies. In this paper we reviewed the molecular features and the main available therapeutic options in pediatric solid cancer, focusing on available targeted drugs and ongoing investigations, aiming at providing a useful tool to navigate the heterogeneity of this promising but complex field.

Quantitative proteomic studies addressing unmet clinical needs in sarcoma

Sarcoma is a rare and complex disease comprising over 80 malignant subtypes that is frequently characterized by poor prognosis. Challenges in clinical management include uncertainties in diagnosis and disease classification, limited prognostic and predictive biomarkers, incompletely understood disease heterogeneity among and within subtypes, lack of effective treatment options, and limited progress in identifying new drug targets and novel therapeutics. Proteomics refers to the study of the entire complement of proteins expressed in specific cells or tissues. Advances in proteomics have included the development of quantitative mass spectrometry (MS)-based technologies which enable analysis of large numbers of proteins with relatively high throughput, enabling proteomics to be studied on a scale that has not previously been possible. Cellular function is determined by the levels of various proteins and their interactions, so proteomics offers the possibility of new insights into cancer biology. Sarcoma proteomics therefore has the potential to address some of the key current challenges described above, but it is still in its infancy. This review covers key quantitative proteomic sarcoma studies with findings that pertain to clinical utility. Proteomic methodologies that have been applied to human sarcoma research are briefly described, including recent advances in MS-based proteomic technology. We highlight studies that illustrate how proteomics may aid diagnosis and improve disease classification by distinguishing sarcoma histologies and identify distinct profiles within histological subtypes which may aid understanding of disease heterogeneity. We also review studies where proteomics has been applied to identify prognostic, predictive and therapeutic biomarkers. These studies traverse a range of histological subtypes including chordoma, Ewing sarcoma, gastrointestinal stromal tumors, leiomyosarcoma, liposarcoma, malignant peripheral nerve sheath tumors, myxofibrosarcoma, rhabdomyosarcoma, synovial sarcoma, osteosarcoma, and undifferentiated pleomorphic sarcoma. Critical questions and unmet needs in sarcoma which can potentially be addressed with proteomics are outlined.

The Outcome of Discontinuing Tyrosine Kinase Inhibitors in Advanced Sarcoma Following a Favorable Tumor Response to Antiangiogenics Therapy

(1) Background: The use of antiangiogenic TKIs (AA-TKIs) has recently emerged as a major paradigm shift in the treatment of advanced sarcoma. However, the feasibility of drug holidays for patients demonstrating a very favorable response remains unknown. (2) Methods: We aim to explore the outcomes of patients with advanced sarcoma who discontinued AA-TKIs after a (near-) complete remission or were long-term responders. Patients with advanced disease were included if they had bilateral or multiple lung metastases, extrapulmonary recurrence, a short disease-free interval, etc., at the initiation of AA-TKIs. (3) Results: A total of 22 patients with AA-TKI discontinuation were analyzed, with a median follow-up of 22.3 months post-discontinuation. Prior to discontinuation, there were four drug-induced complete remissions (CRs), twelve surgical CRs, and six long-term responders. Disease progression was observed in 17/22 (77.3%) patients, with a median of 4.2 months. However, since the majority were still sensitive to the original AA-TKIs and amenable to a second surgical remission, 7 out of these 17 patients achieved a second CR after disease progression and were thus considered as relapse-free post-discontinuation (pd-RFS). Therefore, the pd-RFS and post-discontinuation overall survival (pd-OS) in the last follow-up were 12/22 (54.5%) and 16/22 (72.7%), respectively. Remarkably, surgical CR and drug tapering off (versus abrupt stopping) were associated with a greater pd-RFS and pd-OS (p < 0.05). Furthermore, higher necrosis rates (p = 0.040) and lower neutrophil-to-lymphocyte ratios (NLR) (p = 0.060) before discontinuation tend to have a better pd-RFS. (4) Conclusions: Our results suggest that AA-TKI discontinuation with a taper-off strategy might be safe and feasible in highly selected patients with advanced sarcoma. Surgical CR, NLR, and tumor necrosis rates before discontinuation were potential biomarkers for AA-TKI withdrawal.

Nanomaterial-assisted theranosis of bone diseases

Bone-related diseases refer to a group of skeletal disorders that are characterized by bone and cartilage destruction. Conventional approaches can regulate bone homeostasis to a certain extent. However, these therapies are still associated with some undesirable problems. Fortunately, recent advances in nanomaterials have provided unprecedented opportunities for diagnosis and therapy of bone-related diseases. This review provides a comprehensive and up-to-date overview of current advanced theranostic nanomaterials in bone-related diseases. First, the potential utility of nanomaterials for biological imaging and biomarker detection is illustrated. Second, nanomaterials serve as therapeutic delivery platforms with special functions for bone homeostasis regulation and cellular modulation are highlighted. Finally, perspectives in this field are offered, including current key bottlenecks and future directions, which may be helpful for exploiting nanomaterials with novel properties and unique functions. This review will provide scientific guidance to enhance the development of advanced nanomaterials for the diagnosis and therapy of bone-related diseases.

Metastatic mesenchymal chondrosarcoma showing a sustained response to cabozantinib: A case report

Mesenchymal chondrosarcoma is a rare and aggressive sarcoma subtype with high risk for distant metastases and poor prognosis. Currently NCCN- and ESMO-Guidelines recommend using Ewing sarcoma protocols as standard treatment. Nevertheless, in localized disease overall 5-year survival rates are below 50% whereas in metastatic spread median progression-free survival rates of only 5 months can be expected. Here we present a patient with metastatic osseous spread of mesenchymal chondrosarcoma that showed a sustained clinical improvement and a good partial response on imaging over a period of one year when treated with the multi-tyrosine kinase inhibitor cabozantinib. Although we cannot explain the exact mechanism underlying this treatment effect, tumors with similar genetic patterns might respond to the same therapy as well.

Current progress and open challenges for applying tyrosine kinase inhibitors in osteosarcoma

Osteosarcoma (OS) is a mesenchymal-origin tumor that constitutes the most common primary malignant bone tumor. The survival rate of the patients has significantly improved since the introduction of neoadjuvant chemotherapy and extensive resection, but it has stagnated in recent 40 years. Tyrosine kinase inhibitors (TKIs) have played a key part in the treatment of malignant tumors. In advanced OS, TKIs including anlotinib, apatinib, sorafenib, etc. have significantly improved the progression-free survival of patients, while the overall survival remains unchanged. The main reason is the rapid and inevitable progress of acquired drug resistance of OS. However, as the application of TKIs in OS and other tumors is still in the exploratory phase, its drug resistance mechanism and corresponding solutions are rarely reported. Hence, in this review, we summarize knowledge of the applications of TKIs, the mechanism of TKIs resistance, and the attempts to overcome TKIs resistance in OS, which are the three potentially novel insights of TKIs in OS. Because most evidence is derived from studies using animal and cell models, we also reviewed clinical trials and related bioinformatics data available in public databases, which partially improved our understanding of TKIs applications.

Osteosarcoma

Osteosarcoma is the most common primary malignant tumour of the bone. Osteosarcoma incidence is bimodal, peaking at 18 and 60 years of age, and is slightly more common in males. The key pathophysiological mechanism involves several possible genetic drivers of disease linked to bone formation, causing malignant progression and metastasis. While there have been significant improvements in the outcome of patients with localized disease, with event-free survival outcomes exceeding 60%, in patients with metastatic disease, event-free survival outcomes remain poor at less than 30%. The suspicion of osteosarcoma based on radiographs still requires pathological evaluation of a bone biopsy specimen for definitive diagnosis and CT imaging of the chest should be performed to identify lung nodules. So far, population-based screening and surveillance strategies have not been implemented due to the rarity of osteosarcoma and the lack of reliable markers. Current screening focuses only on groups at high risk such as patients with genetic cancer predisposition syndromes. Management of osteosarcoma requires a multidisciplinary team of paediatric and medical oncologists, orthopaedic and general surgeons, pathologists, radiologists and specialist nurses. Survivors of osteosarcoma require specialized medical follow-up, as curative treatment consisting of chemotherapy and surgery has long-term adverse effects, which also affect the quality of life of patients. The development of osteosarcoma model systems and related research as well as the evaluation of new treatment approaches are ongoing to improve disease outcomes, especially for patients with metastases.