Osteosarcoma relapse after combined modality therapy: an analysis of unselected patients in the Cooperative Osteosarcoma Study Group (COSS)

Sex differences in osteosarcoma survival across the age spectrum: A National Cancer Database analysis (2004-2016)

BACKGROUND

Osteosarcoma displays a bimodal peak in incidence in adolescence and later adulthood. Males are more frequently diagnosed with osteosarcoma in both periods. Males have worse survival than females, which is generally poor at 30-70% 5-years post diagnosis, depending on age, but treatment received is often unaccounted for in survival analyses.

METHODS

Therefore, we estimated sex differences in survival for children and adults stratifying by treatment received and other disease characteristics using the National Cancer Database (2004-2016, n=9017). We estimated sex differences in long-term survival using Kaplan Meier survival curves and Log-Rank p-values. We also estimated hazard ratios (HR) and 95% confidence intervals (CIs) as the measure of association between sex and death using Cox regression.

RESULTS

In all age groups, cases were predominantly male (52-58%). In Kaplan-Meier analyses, males had worse overall survival than females for 0-19, 20-39, and ≥60-year-olds (Log-Rank p<0.05). Females had higher 5- and 10-year survival percentages in all age groups. In adjusted Cox models, males had a higher risk of death among 0-19-year-olds (HRoverall: 1.24, 95% CI: 1.06-1.44; HRnon-metastatic disease: 1.35, 95% CI: 1.12, 1.63, HRlower limb tumors: 1.31, 95% CI: 1.09-1.59). Among 20-39-year-olds, males had an increased risk of death when receiving surgery only (HR: 4.67, 95% CI: 1.44, 15.09). Among those ≥60-year-olds, males had a suggestive increased risk of death overall (HR: 1.17, 95% CI: 0.99-1.39) and a higher risk of death based on some tumor locations, (HRupper limb: 2.52, 95% CI: 1.24, 5.11; HRmidline: 1.36, 95% CI: 1.02, 1.82).

CONCLUSIONS

Our findings suggest that the worse survival among young males compared to females with osteosarcoma persisted after accounting for many major disease characteristics, including treatment received. Collectively, our work points toward other unexplored mechanisms beyond treatment, potentially biologic or otherwise, which may be driving the observed sex differences in long-term survival.

Unlocking the tumor-immune microenvironment in osteosarcoma: insights into the immune landscape and mechanisms

Osteosarcoma has a unique tumor microenvironment (TME), which is characterized as a complex microenvironment comprising of bone cells, immune cells, stromal cells, and heterogeneous vascular structures. These elements are intricately embedded in a mineralized extracellular matrix, setting it apart from other primary TMEs. In a state of normal physiological function, these cell types collaborate in a coordinated manner to maintain the homeostasis of the bone and hematopoietic systems. However, in the pathological condition, i.e., neoplastic malignancies, the tumor-immune microenvironment (TIME) has been shown to promote cancer cells proliferation, migration, apoptosis and drug resistance, as well as immune escape. The intricate and dynamic system of the TIME in osteosarcoma involves crucial roles played by various infiltrating cells, the complement system, and exosomes. This complexity is closely associated with tumor cells evading immune surveillance, experiencing uncontrolled proliferation, and facilitating metastasis. In this review, we elucidate the intricate interplay between diverse cell populations in the osteosarcoma TIME, each contributing uniquely to tumor progression. From chondroblastic and osteoblastic osteosarcoma cells to osteoclasts, stromal cells, and various myeloid and lymphoid cell subsets, the comprehensive single-cell analysis provides a detailed roadmap of the complex osteosarcoma ecosystem. Furthermore, we summarize the mutations, epigenetic mechanisms, and extracellular vesicles that dictate the immunologic landscape and modulate the TIME of osteosarcoma. The perspectives of the clinical implementation of immunotherapy and therapeutic approaches for targeting immune cells are also intensively discussed.

Construction of a 5-Gene super-enhancer-related signature for osteosarcoma prognosis and the regulatory role of TNFRSF11B in osteosarcoma

Osteosarcoma, one of the most common primary malignancies in children and adolescents, has the primary characteristics of a poor prognosis and high rate of metastasis. This study used super-enhancer-related genes derived from two different cell lines to construct five novel super-enhancer-related gene prognostic models for patients with osteosarcoma. The training and testing datasets were used to confirm the prognostic models of the five super-enhancer-related genes, which resulted in an impartial predictive element for osteosarcoma. The immunotherapy and prediction of the response to anticancer drugs have shown that the risk signature of the five super-enhancer-related genes positively correlate with chemosensitivity. Furthermore, functional analysis of the risk signature genes revealed a significant relationship between gene groups and the malignant characteristics of tumours. TNF Receptor Superfamily Member 11b (TNFRSF11B) was selected for functional verification. Silencing of TNFRSF11B suppressed the proliferation, migration, and invasion of osteosarcoma cells in vitro and suppressed osteosarcoma growth in vivo. Moreover, transcriptome sequencing was performed on MG-63 cells to study the regulatory mechanism of TNFRSF11B in osteosarcoma cells, and it was discovered that TNFRSF11B is involved in the development of osteosarcoma via the phosphoinositide 3-kinase signalling pathway. Following the identification of TNFRSF11B as a key gene, we selected an inhibitor that specifically targeted this gene and performed molecular docking simulations. In addition, risedronic acid inhibited osteosarcoma growth at both cellular and molecular levels. In conclusion, the super-enhancer-related gene signature is a viable therapeutic tool for osteosarcoma prognosis and treatment.

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.

Amicis Omnia Sunt Communia: NF-κB Inhibition as an Alternative to Overcome Osteosarcoma Heterogeneity

Tumor heterogeneity poses a significant challenge in osteosarcoma (OS) treatment. In this regard, the "omics" era has constantly expanded our understanding of biomarkers and altered signaling pathways (i.e., PI3K/AKT/mTOR, WNT/β-catenin, NOTCH, SHH/GLI, among others) involved in OS pathophysiology. Despite different players and complexities, many commonalities have been described, among which the nuclear factor kappa B (NF-κB) stands out. Its altered activation is pervasive in cancer, with pleiotropic action on many disease-relevant traits. Thus, in the scope of this article, we highlight the evidence of NF-κB dysregulation in OS and its integration with other cancer-related pathways while we summarize the repertoire of compounds that have been described to interfere with its action. In silico strategies were used to demonstrate that NF-κB is closely coordinated with other commonly dysregulated signaling pathways not only by functionally interacting with several of their members but also by actively participating in the regulation of their transcription. While existing inhibitors lack selectivity or act indirectly, the therapeutic potential of targeting NF-κB is indisputable, first for its multifunctionality on most cancer hallmarks, and secondly, because, as a common downstream effector of the many dysregulated pathways influencing OS aggressiveness, it turns complex regulatory networks into a simpler picture underneath molecular heterogeneity.

System analysis based on Anoikis-related genes identifies MAPK1 as a novel therapy target for osteosarcoma with neoadjuvant chemotherapy

BACKGROUND

Osteosarcoma (OS) is the most common bone malignant tumor in children, and its prognosis is often poor. Anoikis is a unique mode of cell death.However, the effects of Anoikis in OS remain unexplored.

METHOD

Differential analysis of Anoikis-related genes was performed based on the metastatic and non-metastatic groups. Then LASSO logistic regression and SVM-RFE algorithms were applied to screen out the characteristic genes. Later, Univariate and multivariate Cox regression was conducted to identify prognostic genes and further develop the Anoikis-based risk score. In addition, correlation analysis was performed to analyze the relationship between tumor microenvironment, drug sensitivity, and prognostic models.

RESULTS

We established novel Anoikis-related subgroups and developed a prognostic model based on three Anoikis-related genes (MAPK1, MYC, and EDIL3). The survival and ROC analysis results showed that the prognostic model was reliable. Besides, the results of single-cell sequencing analysis suggested that the three prognostic genes were closely related to immune cell infiltration. Subsequently, aberrant expression of two prognostic genes was identified in osteosarcoma cells. Nilotinib can promote the apoptosis of osteosarcoma cells and down-regulate the expression of MAPK1.

CONCLUSIONS

We developed a novel Anoikis-related risk score model, which can assist clinicians in evaluating the prognosis of osteosarcoma patients in clinical practice. Analysis of the tumor immune microenvironment and chemotherapeutic drug sensitivity can provide necessary insights into subsequent mechanisms. MAPK1 may be a valuable therapeutic target for neoadjuvant chemotherapy in osteosarcoma.

Pulmonary Surgical Margins for Metastatic Osteosarcoma: Is Negative Margin Enough?

BACKGROUND

In advanced osteosarcoma, the lung is the most frequent site of distant metastasis, with metastasectomy often used for local disease control. The influence of pulmonary resection margin length on outcomes for osteosarcoma has not been well explored. This study sought to evaluate the impact of margin length relative to tumor size on local recurrence and survival in lung-limited metastatic osteosarcoma.

METHODS

Patients with metastatic osteosarcoma who underwent lung resection between 2000 and 2020 were identified from a single institution. Clinicopathologic variables were collected. The margin length-to-tumor size ratio (MTR) was calculated per nodule and classified relative to an MTR of 0.5. The primary outcome was development of local recurrence per nodule. Multivariate logistic regression was used to investigate covariates.

RESULTS

A total of 142 patients with 689 nodules met inclusion criteria, with mean age of 35.6 years (interquartile range [IQR], 20.9-46.6 years). Patients were predominantly male (n = 87; 61.3%) and White (n = 106; 72.5%). Most nodules (n = 644; 93.5%) were resected through thoracotomy. The mean tumor size was 0.8 cm (IQR, 0.5-1.70 cm), with an average margin length of 0.3 cm (IQR, 0.1-0.7 cm). Among all nodules, 299 (43.4%) had an MTR >0.5. Systemic therapy was received by 94 patients (66.2%) preoperatively and by 100 patients (70.4%) postoperatively. Importantly, the study found that an MTR >0.5 conferred a protective effect against disease recurrence (hazard ratio, 0.67; 95% CI, 0.52-0.87; P = .003).

CONCLUSIONS

In resected pulmonary metastatic osteosarcoma, a margin length greater than one-half the size of the pulmonary nodule is associated with a lower incidence of local disease recurrence. This finding has implications for the subsequent need for additional therapy and disease-free status, thus meriting attentive intraoperative consideration.

Predictors of pulmonary metastases on chest computed tomography in children and adolescents with osteosarcoma-tips for qualifying patients for thoracotomy

BACKGROUND

Osteosarcoma is the most common primary malignant bone tumour in children and adolescents. Lungs are the most frequent and often the only site of metastatic disease. The presence of pulmonary metastases is a significant unfavourable prognostic factor. Thoracotomy is strongly recommended in these patients, while computed tomography (CT) remains the gold imaging standard. The purpose of our study was to create tools for the CT-based qualification for thoracotomy in osteosarcoma patients in order to reduce the rate of useless thoracotomies.

METHODS

Sixty-four osteosarcoma paediatric patients suspected of lung metastases on CT and their first-time thoracotomies (n = 100) were included in this retrospective analysis. All CT scans were analysed using a compartmental evaluation method based on the number and size of nodules. Calcification and location of lung lesions were also analysed. Inter-observer reliability between two experienced radiologists was assessed. The CT findings were then correlated with the histopathological results of thoracotomies. Various multivariate predictive models (logistic regression, classification tree and random forest) were built and predictors of lung metastases were identified.

RESULTS

All applied models proved that calcified nodules on the preoperative CT scan best predict the presence of pulmonary metastases. The rating of the operated lung on the preoperative CT scan, dependent on the number and size of nodules, and the total number of nodules on this scan were also found to be important predictors. All three models achieved a relatively high sensitivity (72-92%), positive predictive value (81-90%) and accuracy (74-79%). The positive predictive value of each model was higher than of the qualification for thoracotomy performed at the time of treatment. Inter-observer reliability was at least substantial for qualitative variables and excellent for quantitative variables.

CONCLUSIONS

The multivariate models built and tested in our study may be useful in the qualification of osteosarcoma patients for metastasectomy through thoracotomy and may contribute to reducing the rate of unnecessary invasive procedures in the future.

Liquiritigenin Induces Cell Cycle Arrest and Apoptosis in Lung Squamous Cell Carcinoma

Liquiritigenin (LQ), as a dihydroflavone monomer compound extracted from Glycyrrhiza uralensis Fisch, has been demonstrated to show anti-tumor effects in multiple human cancers, including lung adenocarcinoma. Our study aimed to explore its role in lung squamous cell carcinoma (LSCC) development and the related mechanism. The effects of LQ on SK-MES-1 and NCI-H520 cell proliferation, cell cycle, and apoptosis were investigated. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and colony formation assays revealed that LQ inhibited LSCC cell viability and proliferation in a dose- and time-dependent manner. Flow cytometry analysis demonstrated that LQ promoted G2/M cell cycle arrest, cell apoptosis, and loss of mitochondrial membrane potential. In vivo assays showed that LQ administration suppressed tumor growth in nude mice. Additionally, LQ treatment reduced the levels of phosphorylated PI3K, AKT, and mTOR levels in LSCC cells. Pretreatment with the PI3K inhibitor LY294002 antagonized the LQ-mediated effects on cell proliferation, cell cycle arrest, and apoptosis in LSCC cells. Collectively, LQ induces cell cycle arrest and apoptosis in LSCC by inactivating the PI3K/AKT/mTOR pathway.

Autologous HER2-specific CAR T cells after lymphodepletion for advanced sarcoma: a phase 1 trial

In this prospective, interventional phase 1 study for individuals with advanced sarcoma, we infused autologous HER2-specific chimeric antigen receptor T cells (HER2 CAR T cells) after lymphodepletion with fludarabine (Flu) ± cyclophosphamide (Cy): 1 × 108 T cells per m2 after Flu (cohort A) or Flu/Cy (cohort B) and 1 × 108 CAR+ T cells per m2 after Flu/Cy (cohort C). The primary outcome was assessment of safety of one dose of HER2 CAR T cells after lymphodepletion. Determination of antitumor responses was the secondary outcome. Thirteen individuals were treated in 14 enrollments, and seven received multiple infusions. HER2 CAR T cells expanded after 19 of 21 infusions. Nine of 12 individuals in cohorts A and B developed grade 1-2 cytokine release syndrome. Two individuals in cohort C experienced dose-limiting toxicity with grade 3-4 cytokine release syndrome. Antitumor activity was observed with clinical benefit in 50% of individuals treated. The tumor samples analyzed showed spatial heterogeneity of immune cells and clustering by sarcoma type and by treatment response. Our results affirm HER2 as a CAR T cell target and demonstrate the safety of this therapeutic approach in sarcoma. ClinicalTrials.gov registration: NCT00902044 .

Unveiling research trends in the prognosis of osteosarcoma: A bibliometric analysis from 2000 to 2022

Background

Osteosarcoma (OSA) is the most prevalent form of malignant bone tumor in children and adolescents, producing osteoid and immature bone. Numerous high quality studies have been published in the OSA field, however, no bibliometric study related to this area has been reported thus far. Therefore, the present study retrieved the published data from 2000 to 2022 to reveal the dynamics, development trends, hotspots and future directions of the OSA.

Methods

Publications regard to osteogenic sarcoma and prognosis were searched in the core collection on Web of Science database. The retrieved publications were analyzed by publication years, journals, categories, countries, citations, institutions, authors, keywords and clusters using the two widely available bibliometric visualization tools, VOS viewer (Version 1.6.16), Citespace (Version 6.2. R1).

Results

A total of 6260 publications related to the current topic were retrieved and analyzed, revealing exponential increase in the number of publications with an improvement in the citations on the OSA over time, in which China and the USA are the most productive nations. Shanghai Jiao Tong University, University of Texas System and Harvard University are prolific institutions, having highest collaboration network. Oncology Letters and Journal of Clinical Oncology are the most productive and the most cited journals respectively. The Wang Y is a prominent author and articles published by Bacci G had the highest number of citations indicating their significant impact in the field. According to keywords analysis, osteosarcoma, expression and metastasis were the most apparent keywords whereas the current research hotspots are biomarker, tumor microenvironment, immunotherapy and DNA methylation.

Conclusion

Our findings offer valuable information for researchers to understand the current research status and the necessity of future research to mitigate the mortality of the OS patients.

Role of bone scintigraphy (bone scan) in skeletal osteosarcoma: A retrospective audit and review from tertiary oncology centre

Introduction

Bone scan is a investigation which uses radionuclide phosphonate compound for whole skeletal survey. In this current study we have done the analysis of the role of bone scan in skeletal osteosarcoma at tertiary oncology care centre.

Material & methods

This is a retrospective study conducted in a tertiary oncology centre from January 2022 to February 2023. A total of 92 patients with skeletal OGS were included in our study undergone 99 mTCcMDP whole body bone scan. 99 mTc MDP was prepared freshly every morning and dose for each patient were calculated as per EANM guidelines. Images were acquired 2-3 h of post injection. All images were acquired at GE infinia dual head machine with peak setting at 140Kev and LEAP collimator. Suspicious lesions on planer bone scan were correlated with SPECT fused with CT. All the bone scans were reviewed retrospectively by two independent nuclear medicine physicians.

Results

In this study group, 86 patients with biopsy proven skeletal OGS underwent 99 mTCcMDP bone scan of which 63 were males and 23 were females (2.7:1) with age of study group ranging from 7years to 48years. Patients referred for bone scan were retrospectively categorized in two groups, first group patients (52) were referred for initial staging of disease and second group of patients (34) were referred for follow-up or re-staging of the disease. Total 09 patients showed distant skeletal metastases on bone scan, out of which 05 were in initial staging group and 04 in follow up group.

Conclusion

Osteosarcoma has propensity to metastasize to many sites in the body however most common site being lung followed by skeletal, nodal and rarely soft tissue metastasis. Bone scan enjoys a optimal sensitivity in case of osteosarcoma to detect skeletal metastasis but have low specificity. However being a cost effective and faster investigation makes it a wise investigation of choice in case of osteosarcoma for skeletal metastasis evaluation.

Identification of therapeutic targets and prognostic biomarkers in the Siglec family of genes in tumor immune microenvironment of sarcoma

Sarcomas (SARC) are a highly heterogeneous cancer type that is prone to recurrence and metastasis. Numerous studies have confirmed that Siglecs are involved in immune signaling and play a key role in regulating immune responses in inflammatory diseases and various cancers. However, studies that systematically explore the therapeutic and prognostic value of Siglecs in SARC patients are very limited. The online databases GEPIA, UALCAN, TIMER, The Kaplan-Meier Plotter, GeneMANIA, cBioPortal, and STING were used in this study. IHC staining was performed on the collected patient tissues, and clinical data were statistically analyzed. The transcript levels of most Siglec family members showed a high expression pattern in SARC. Compared with normal tissues, Siglec-5, Siglec-10, and Siglec-12 were abnormally highly expressed in tumor tissues. Importantly, Siglec-15 was significantly associated with poor prognosis. Functional enrichment analysis showed that the Siglec family was mainly enriched in hematopoietic cell lineages. The genes associated with molecular mutations in the Siglec family were mainly TP53 and MUC16, among which Siglec-2 and Siglec-15 were significantly associated with the survival of patients. The expression levels of all Siglec family members were significantly correlated with various types of immune cells (B cells, CD8 + T cells, CD4 + T cells, macrophages, neutrophils and dendritic cells). Furthermore, a significant correlation was found between the somatic copy number changes of all Siglec molecules and the abundance of immune infiltrates. Our study paints a promising vision for the development of immunotherapy drugs and the construction of prognostic stratification models by investigating the therapeutic and prognostic potential of the Siglec family for SARC.

The combination of baseline neutrophil to lymphocyte ratio and dynamic changes during treatment can better predict the survival of osteosarcoma patients

Background

Osteosarcoma is a primary malignant bone tumor with a high metastatic potential that accounts for a significant proportion of all bone tumors. The prognosis for patients with metastatic or recurrence disease remains poor. The neutrophil-to-lymphocyte ratio (NLR) has become a potential prognostic biomarker for cancer. Recent evidence suggests that the dynamic changes in neutrophil-to-lymphocyte ratio (NLR) during treatment may be more informative in predicting patient prognosis, but the value of dynamic NLR in osteosarcoma has not yet been determined.

Methods

This retrospective study retrospectively analyzed the clinical information of 251 osteosarcoma patients diagnosed and treated in West China Hospital of Sichuan University, explored the impact of baseline NLR and changes in NLR during treatment on the prognosis of osteosarcoma patients, and further combined baseline NLR with Delta NLR to build an NLR staging system.

Results

The results showed that both baseline NLR and delta NLR had some predictive ability for the prognosis of osteosarcoma patients (P = 6.90e-4, P = 0.022). Patients with high baseline NLR were more likely to have a decrease in delta NLR (P = 1.24e-10). The NLR stage had a better predictive ability than baseline NLR and delta NLR, and was an independent prognostic factor for overall survival in osteosarcoma patients HR: 2.456 (1.625-3.710) (P = 1.97e-05).

Conclusion

NLR has value in continuous monitoring, and continuous monitoring of NLR can better predict the survival of osteosarcoma patients compared to baseline NLR.

Tyrosine kinase inhibitor therapy in pediatric sarcoma: Prognostic implications of pulmonary metastatic cavitation

PURPOSES

This study aims to ascertain the prevalence of cavitations in pulmonary metastases among pediatric and young adult patients with sarcoma undergoing tyrosine kinase inhibitor (TKI) therapy, and assess whether cavitation can predict clinical response and survival outcomes.

METHODS

In a single-center retrospective analysis, we examined chest computed tomography (CT) scans of 17 patients (median age 16 years; age range: 4-25 years) with histopathologically confirmed bone (n = 10) or soft tissue (n = 7) sarcoma who underwent TKI treatment for lung metastases. The interval between TKI initiation and the onset of lung nodule cavitation and tumor regrowth were assessed. The combination of all imaging studies and clinical data served as the reference standard for clinical responses. Progression-free survival (PFS) was compared between patients with cavitating and solid nodules using Kaplan-Meier survival analysis and log-rank test.

RESULTS

Five out of 17 patients (29%) exhibited cavitation of pulmonary nodules during TKI therapy. The median time from TKI initiation to the first observed cavitation was 79 days (range: 46-261 days). At the time of cavitation, all patients demonstrated stable disease. When the cavities began to fill with solid tumor, 60% (3/5) of patients exhibited progression in other pulmonary nodules. The median PFS for patients with cavitated pulmonary nodules after TKI treatment (6.7 months) was significantly longer compared to patients without cavitated nodules (3.8 months; log-rank p-value = .03).

CONCLUSIONS

Cavitation of metastatic pulmonary nodules in sarcoma patients undergoing TKI treatment is indicative of non-progressive disease, and significantly correlates with PFS.

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.

New emerging targets in osteosarcoma therapy: PTEN and PI3K/Akt crosstalk in carcinogenesis

Osteosarcoma (OS) is a malignant bone carcinoma that affects people in childhood and adulthood. The heterogeneous nature and chromosomal instability represent certain characteristics of OS cells. These cancer cells grow and migrate abnormally, making the prognosis undesirable for patients. Conventional and current treatments fail to completely eradicate tumor cells, so new therapeutics targeting genes may be considered. PI3K/Akt is a regulator of events such as growth, cell death, migration, and differentiation, and its expression changes during cancer progression. PTEN reduces PI3K/Akt expression, and its mutations and depletions have been reported in various tumors. Experimental evidence shows that there is upregulation of PI3K/Akt and downregulation of PTEN in OS. Increasing PTEN expression may suppress PI3K/Akt to minimize tumorigenesis. In addition, PI3K/Akt shows a positive association with growth, metastasis, EMT and metabolism of OS cells and inhibits apoptosis. Importantly, overexpression of PI3K/Akt causes drug resistance and radio-resistance and its level can be modulated by miRNAs, lncRNAs and circRNAs. Silencing PI3K/Akt by compounds and drugs can suppress OS. Here, we review in detail the function of the PTEN/PI3K/Akt in OS, revealing its biological function, function in tumor progression, resistance to therapy, and pharmacological significance.

Survival outcomes and surgical morbidity based on surgical approach to pulmonary metastasectomy in pediatric, adolescent and young adult patients with osteosarcoma

BACKGROUND

Thoracotomy is considered the standard surgical approach for the management of pulmonary metastases in osteosarcoma (OST). Several studies have identified the advantages of a thoracoscopic approach, however, the clinical significance of thoracotomy compared to thoracoscopy is yet to be evaluated in a randomized trial.

AIMS

The primary aim was to determine the survival outcomes in OST patients based on surgical approach for pulmonary metastasectomy (PM) and secondary aim was to assess the post-operative morbidities of OST PM through various surgical approaches.

MATERIALS AND METHODS

We conducted a single institution retrospective study to compare survival outcomes and surgical morbidity according to the surgical approach of the management of pulmonary metastases in patients with OST.

RESULTS

Sixty-one patients with OST underwent PM. Twenty-one patients were metastatic at diagnosis and underwent PM during primary treatment; nine had thoracotomy, six thoracoscopy, and six combined thoracoscopy with thoracotomy (CTT). Forty-three patients with first pulmonary relapse or progression underwent PM; 18 had thoracotomy, 16 thoracoscopy and nine CTT. There was no difference in survival between surgical approaches. There were significantly more postoperative morbidities associated with thoracotomy for initial PM (pain and postoperative chest tube placement), and for PM at first relapse (pneumothoraces, pain, Foley catheter use and prolonged hospitalizations).

CONCLUSION

Our study demonstrates that patients with OST pulmonary metastases have comparable poor outcomes despite varying surgical approaches for PM. There were significantly more postoperative morbidities associated with thoracotomy for PM. Surgical bias and other competing risks could not be assessed given the limitations of a retrospective study and may be addressed in a prospective trial evaluating surgical approach for PM in OST.

Long intergenic non-coding RNA DIO3OS promotes osteosarcoma metastasis via activation of the TGF-β signaling pathway: a potential diagnostic and immunotherapeutic target for osteosarcoma

BACKGROUND

The aim of this study was to determine the underlying potential mechanisms and function of DIO3OS, a lincRNA in osteosarcoma and clarify that DIO3OS can be used as a potential diagnostic biomarker and immunotherapeutic target.

METHODS

The expression matrix data and clinical information were obtained from XENA platform of UCSC and GEO database as the test cohorts. The external validation cohort was collected from our hospital. Bioinformatics analysis was used to annotate the biological function of DIO3OS. Immune infiltration and immune checkpoint analysis were applied to evaluate whether DIO3OS can be used as an immunotherapeutic target. ROC curves and AUC were established to assess the diagnostic value of DIO3OS for differentiating patients from other subtypes sarcoma. The expression analysis was detected by qRT-PCR, western blot, and immunohistochemical. Wound healing assay and Transwell assay were applied to determine the migration and invasion function of DIO3OS in osteosarcoma cell lines. The tail vein injection osteosarcoma cells metastases model was used in this research.

RESULTS

High expression of DIO3OS was identified as a risk lincRNA for predicting overall survival of osteosarcoma in test cohort. The outcomes of experiments in vitro and in vivo showed that low expression of DIO3OS limited osteosarcoma tumor metastasis with inhibiting TGF-β signaling pathway. Immune checkpoint genes (CD200 and TNFRSF25) expressions were inhibited in the low DIO3OS expression group. The DIO3OS expression can be applied to reliably distinguish osteosarcoma from lipomatous neoplasms, myomatous neoplasms, nerve sheath tumors, and synovial-like neoplasms. This result was further validated in the validation cohort.

CONCLUSIONS

In conclusion, our outcomes indicated that DIO3OS is a potential diagnostic and prognostic biomarker of osteosarcoma, emphasizing its potential as a target of immunotherapy to improve the treatment of osteosarcoma through TGF-β signaling pathway.

TRIAL REGISTRATION NUMBER

The present retrospectively study was approved by the Ethics Committee of The Second Affiliated Hospital of Nanchang University [Review (2020) No. (115)].

Solitary pulmonary metastases at first recurrence of osteosarcoma: Presentation, treatment, and survival of 219 patients of the Cooperative Osteosarcoma Study Group

BACKGROUND

To evaluate patient and tumour characteristics, treatment and their impact on survival in patients with a solitary pulmonary metastasis at first relapse of high-grade osteosarcoma.

PROCEDURE

Two-hundred and nineteen consecutive patients who had achieved a complete surgical remission and then developed a solitary pulmonary metastasis at first recurrence of high-grade osteosarcoma were retrospectively reviewed.

RESULTS

Two hundred and three (94.9%) of 214 patients achieved a second complete remission. After a median time from initial diagnosis of osteosarcoma to first relapse of 2.3 years (range, 0.3-18.8 years), actuarial post-relapse overall survival after 2 and 5 years was 72.0% and 51.2%. Post-relapse event-free survival was 39.1% and 31.1%. Median follow-up time was 3.2 years (range, 0.1-29.4 years). A longer time until first relapse and diagnosis due to imaging were positive prognostic factors in uni- and multivariate analyses, as were a second complete surgical remission and, in regard to death, the absence of a subsequent relapse. The use of salvage chemotherapy and radiotherapy were not associated with patient outcomes, nor was the surgical approach (thoracoscopy vs. thoracotomy) nor the exploration (uni- vs. bilateral).

CONCLUSION

Approximately half of the patients who experience a solitary pulmonary relapse at first recurrence of osteosarcoma remain alive 5 years after this first relapse. Only one third will remain disease-free. A complete surgical resection of the lesion is essential for long-term survival while relapse chemotherapy does not seem to improve survival. Innovative therapies are required to improve outcomes.

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.

Spectral computed tomography-guided radiotherapy of osteosarcoma utilizing BiOI nanosheets

As an aggressive malignant bone tumor, osteosarcoma (OS) is usually found in children and adolescents. Computed tomography (CT) is an important tool for the clinical evaluation of osteosarcoma, but limits to low diagnostic specificity due to single parameters of traditional CT and modest signal-to-noise ratio of clinical iodinated contrast agents. As one kind of spectral CT, dual-energy CT (DECT), with the advantage of a provision of multi-parameter information, makes it possible to acquire the best signal-to-noise ratio image, accurate detection, as well as imaging-guided therapy of bone tumors. Hereby, we synthesized BiOI nanosheets (BiOI NSs) as a DECT contrast agent with superior imaging capability compared to iodine agents for clinical detection of OS. Meanwhile, the synthesized BiOI NSs with great biocompatibility is able to achieve effective radiotherapy (RT) by enhancing X-ray dose deposition at the tumor site, leading to DNA damage, which in turn inhibits tumor growth. This study offers a promising new avenue for DECT imaging-guided treatment of OS. STATEMENT OF SIGNIFICANCE: Osteosarcoma (OS) is a common primary malignant bone tumor. Traditional surgical procedures and conventional CT scans are often used for the treatment and monitoring of OS, but the effects are generally unsatisfactory. In this work, BiOI nanosheets (NSs) was reported for dual-energy CT (DECT) imaging-guided OS radiotherapy. The powerful and constant X-ray absorption of BiOI NSs at any energy guarantees excellent enhanced DECT imaging performance, allowing detailed visualization of OS through images with a better signal-to-noise ratio and guiding radiotherapy process. The deposition of X-rays could be greatly enhanced by Bi atoms to induce serious DNA damage in radiotherapy. Taken together, the BiOI NSs for DECT-guided radiotherapy will greatly improve the current treatment status of OS.

Comprehensive analysis of angiogenesis pattern and related immune landscape for individual treatment in osteosarcoma

Postoperative recurrence and metastasis are the main reasons for the poor prognosis of osteosarcoma (OS). Currently, an ideal predictor for not only prognosis but also drug sensitivity and immunotherapy responses in OS patients is urgently needed. Angiogenesis plays a crucial role in tumour progression, which suggests its immense potential for predicting prognosis and responses to immunotherapy for OS. Angiogenesis patterns in OS were explored in depth in this study to construct a prognostic model called ANGscore and clarify the underlying mechanism involved in the immune microenvironment. The efficacy and robustness of the model were validated in multiple datasets, including bulk RNA-seq datasets (TARGET-OS, GSE21257), a single-cell RNA-seq dataset (GSE152048) and immunotherapy-related datasets (GSE91061, GSE173839). OS patients with a high ANGscore had a worse prognosis, accompanied by the immune desert phenotype. Pseudotime and cellular communication analyses in scRNA-seq data revealed that as the ANGscore increased, the malignant degree of cells increased, and IFN-γ signalling was involved in tumour progression and regulation of the tumour immune microenvironment. Furthermore, the ANGscore was associated with immune cell infiltration and the response rate to immunotherapy. OS patients with high ANGscore might be resistant to uprosertib, and be sensitive to VE821, AZD6738 and BMS.345541. In conclusion, we established a novel ANGscore system by comprehensively analysing the expression pattern of angiogenesis genes, which can accurately differentiate the prognosis and immune characteristics of OS populations. Additionally, the ANGscore can be used for patient stratification during immunotherapy, and guide individualized treatment strategies.

Longitudinal characterization of primary osteosarcoma and derived subcutaneous and orthotopic relapsed patient-derived xenograft models

Osteosarcoma is a rare bone cancer in adolescents and young adults with a dismal prognosis because of metastatic disease and chemoresistance. Despite multiple clinical trials, no improvement in outcome has occurred in decades. There is an urgent need to better understand resistant and metastatic disease and to generate in vivo models from relapsed tumors. We developed eight new patient-derived xenograft (PDX) subcutaneous and orthotopic/paratibial models derived from patients with recurrent osteosarcoma and compared the genetic and transcriptomic landscapes of the disease progression at diagnosis and relapse with the matching PDX. Whole exome sequencing showed that driver and copy-number alterations are conserved from diagnosis to relapse, with the emergence of somatic alterations of genes mostly involved in DNA repair, cell cycle checkpoints, and chromosome organization. All PDX patients conserve most of the genetic alterations identified at relapse. At the transcriptomic level, tumor cells maintain their ossification, chondrocytic, and trans-differentiation programs during progression and implantation in PDX models, as identified at the radiological and histological levels. A more complex phenotype, like the interaction with immune cells and osteoclasts or cancer testis antigen expression, seemed conserved and was hardly identifiable by histology. Despite NSG mouse immunodeficiency, four of the PDX models partially reconstructed the vascular and immune-microenvironment observed in patients, among which the macrophagic TREM2/TYROBP axis expression, recently linked to immunosuppression. Our multimodal analysis of osteosarcoma progression and PDX models is a valuable resource to understand resistance and metastatic spread mechanisms, as well as for the exploration of novel therapeutic strategies for advanced osteosarcoma.

Imaging of pediatric bone tumors: A COG Diagnostic Imaging Committee/SPR Oncology Committee White Paper

Malignant primary bone tumors are uncommon in the pediatric population, accounting for 3%-5% of all pediatric malignancies. Osteosarcoma and Ewing sarcoma comprise 90% of malignant primary bone tumors in children and adolescents. This paper provides consensus-based recommendations for imaging in children with osteosarcoma and Ewing sarcoma at diagnosis, during therapy, and after therapy.

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.

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.

Surgical margin assessment of bone tumours: A systematic review of current and emerging technologies

Osteosarcoma is the most common malignant tumour of the bone. Complete surgical excision is critical to achieve optimal outcomes and lower recurrence rates. However, accurate assessment of tumour margins remains a challenge and multiple technologies are employed for this purpose. The aim of this study is to highlight current and emerging technologies and their efficacy in detecting clear bone margins intraoperatively, through a systematic review of the literature. The following databases were searched using the OVID platform: Medline, Embase, Global Health and Google Scholar. Studies were screened using predetermined eligibility criteria. Data was extracted based on study and patient characteristics, modes of detection, and commercial availability, followed by quality assessment. A total of 17 studies were included. The primary diagnosis varied, with osteosarcoma being reported by 9 studies. Three studies reported relapse, ranging between 17.6%-48%. Twelve studies reported non-invasive imaging as the mode of detection used, while 4 studies reported the use of frozen section. MRI and CT were found to have an accuracy of up to 93 %. Raman spectroscopy was reported to have an accuracy, sensitivity, and specificity of 69%, 58.8% and 83.3% respectively. CT had a sensitivity and specificity up to 83% and 100%, respectively. In conclusion, there seems to be high potential for the use of multimodal technologies to increase the accuracy of intraoperative margin assessment. Although imaging modalities possess a fair level of accuracy, they carry the risk of radiation exposure, are expensive, and cannot be used in-situ. Future clinical trials are needed to test the effectiveness of these technologies to measure the diagnostic accuracy and overall patient survival.

Metachronous Osteosarcoma, A Differential Diagnosis to be Considered in Children With Osteosarcoma: A Review of Literature and a Case From Our Center

Metachronous osteosarcomas (MOS) are currently defined as tumors that arise in a way and site unusual for typical metastasis. In this article, we reviewed the recent literature on the occurrence of metachronous osteosarcoma and presented a case from our center. Our patient, a 10-year-old girl, presented with metachronous osteoblastic osteosarcoma of the left distal femur ∼5 years after the successful treatment for osteosarcoma of the right distal femur. Even after several relapses, complete remission (CR) was achieved after the first osteosarcoma and after the metachronous osteosarcoma. The literature research revealed that metachronous osteosarcoma occurs in 3.4 to 5.4% of osteosarcoma patients. The time interval between the diagnosis of the initial osteosarcoma and the metachronous tumor ranged from 0.2 to 14.3 years (median 2.5 y). MOS appears to have differences in localization and metastatic spread, as well as a different survival pattern compared with primary osteosarcoma and osteosarcoma recurrence. Survival (median 4.3 y, range 0 to 24.6 y) appears to be associated with the time interval to diagnosis of MOS. In particular, early MOS (<24 mo after primary diagnosis) seem to have a poorer prognosis. Therefore, the occurrence of MOS at oncological unusual sites should be considered as a differential diagnosis in osteosarcoma survivors.

Clinical Outcomes of Patients With Osteosarcoma Experiencing Relapse or Progression: A Single-institute Experience

BACKGROUND

Patients with osteosarcoma who experience relapse or progression [R/P] have a poor prognosis.

METHODS

Data from 30 patients who experienced R/P among 59 with a diagnosis of high-grade osteosarcoma, who were younger than 40 years old between 2000 and 2019, were retrospectively analyzed to identify prognostic and therapeutic factors influencing their outcomes.

RESULTS

The 5-year overall survival [OS] rates after the last R/P of patients experiencing first [n=30], second [n=14], and third [n=9] R/P were 50.3%, 51.3%, and 46.7%, respectively. Multivariate analysis did not identify any independent risk factors affecting OS. The 5-year PFS rate of the 30 patients after first R/P was 22.4%, and multivariate analysis identified histologic subtype and curative local surgery as independent risk factors influencing PFS. Long [>6 mo] partial response was observed in three patients treated using temozolomide+etoposide, irinotecan+carboplatin, or regorafenib.

CONCLUSIONS

OS rate in the patients with osteosarcoma experiencing R/P included in this study was markedly higher than that reported previously, mainly due to the surgical total removal of tumors, even after subsequent R/P. The recent establishment of salvage chemotherapy or molecular targeted therapy may also increase survival rates in a subgroup of patients.

Naturally occurring canine sarcomas: Bridging the gap from mouse models to human patients through cross-disciplinary research partnerships

Fueled by support from the National Cancer Institute's "Cancer Moonshot" program, the past few years have witnessed a renewed interest in the canine spontaneous cancer model as an invaluable resource in translational oncology research. Increasingly, there is awareness that pet dogs with cancer provide an accessible bridge to improving the efficiency of cancer drug discovery and clinical therapeutic development. Canine tumors share many biological, genetic, and histologic features with their human tumor counterparts, and most importantly, retain the complexities of naturally occurring drug resistance, metastasis, and tumor-host immune interactions, all of which are difficult to recapitulate in induced or genetically engineered murine tumor models. The utility of canine models has been particularly apparent in sarcoma research, where the increased incidence of sarcomas in dogs as compared to people has facilitated comparative research resulting in treatment advances benefitting both species. Although there is an increasing awareness of the advantages in using spontaneous canine sarcoma models for research, these models remain underutilized, in part due to a lack of more permanent institutional and cross-institutional infrastructure to support partnerships between veterinary and human clinician-scientists. In this review, we provide an updated overview of historical and current applications of spontaneously occurring canine tumor models in sarcoma research, with particular attention to knowledge gaps, limitations, and growth opportunities within these applications. Furthermore, we propose considerations for working within existing veterinary translational and comparative oncology research infrastructures to maximize the benefit of partnerships between veterinary and human biomedical researchers within and across institutions to improve the utility and application of spontaneous canine sarcomas in translational oncology research.

Prognostic Impact of Pulmonary Metastasectomy in Bone Sarcoma Patients: A Retrospective, Single-Centre Study

This retrospective study aimed at analyzing the impact of metastasectomy on post-metastasis survival (PMS) in bone sarcoma patients with lung metastases. Altogether, 47 bone sarcoma patients (24 males, median age at diagnosis of lung metastases: 21.8 (IQR: 15.6–47.3) years) with primary (n = 8) or secondary (n = 39) lung metastases treated at a single university hospital were retrospectively included. Based on a propensity score, inverse probability of treatment weight (IPTW) was calculated to account for selection bias whether patients had undergone metastasectomy or not. The most common underlying histology was osteosarcoma (n = 37; 78.7%). Metastasectomy was performed in 39 patients (83.0%). Younger patients (p = 0.025) with singular (p = 0.043) and unilateral lesions (p = 0.024), as well as those with an interval ≥ 9 months from primary diagnosis to development of lung metastases (p = 0.024) were more likely to undergo metastasectomy. Weighted 1- and 3-year PMS after metastasectomy was 80.8% and 58.3%, compared to 88.5% and 9.1% for patients who did not undergo metastasectomy. Naive Cox-regression analysis demonstrated a significantly prolonged PMS for patients with metastasectomy (HR: 0.142; 95%CI: 0.045–0.450; p = 0.001), which was confirmed after IPTW-weighting (HR: 0.279; 95%CI: 0.118–0.662; p = 0.004), irrespective of age, time to metastasis, and the number of lesions. In conclusion, metastasectomy should be considered in bone sarcoma patients with lung metastases, after carefully considering the individual risks, to possibly improve PMS.

ETC-159, an Upstream Wnt inhibitor, Induces Tumour Necrosis via Modulation of Angiogenesis in Osteosarcoma

There is an increasing urgency in the search for new drugs to target high-grade cancers such as osteosarcomas (OS), as these have limited therapeutic options and poor prognostic outlook. Even though key molecular events leading to tumorigenesis are not well understood, it is widely agreed that OS tumours are Wnt-driven. ETC-159, a PORCN inhibitor that inhibits the extracellular secretion of Wnt, has recently progressed on to clinical trials. In vitro and in vivo murine and chick chorioallantoic membrane xenograft models were established to examine the effect of ETC-159 on OS. Consistent with our hypothesis, we noted that ETC-159 treatment not only resulted in markedly decreased β-catenin staining in xenografts, but also increased tumour necrosis and a significant reduction in vascularity-a hereby yet undescribed phenotype following ETC-159 treatment. Through further understanding the mechanism of this new window of vulnerability, therapies can be developed to potentiate and maximize the effectiveness of ETC-159, further increasing its clinical utility for the treatment of OS.

Establishment, Maintenance, and Performance of the Cooperative Osteosarcoma Study Group (COSS)

INTRODUCTION

Osteosarcoma treatment has benefitted greatly from collaborative research. This paper describes the history and accomplishments of the Cooperative Osteosarcoma Study Group (COSS), mainly dedicated to clinical questions, as well as remaining challenges.

MATERIALS AND METHODS

Narrative review of over four decades of uninterrupted collaboration within the multi-national German-Austrian-Swiss COSS group.

RESULTS

Since its very first prospective osteosarcoma trial starting in 1977, COSS has continuously been able to provide high-level evidence on various tumor- and treatment-related questions. This includes both the cohort of patients enrolled into prospective trials as well as those patients excluded from them for various reasons, followed in a prospective registry. Well over one hundred disease-related publications attest to the group's impact on the field. Despite these accomplishments, challenging problems remain.

DISCUSSION

Collaborative research within a multi-national study group resulted in better definitions of important aspects of the most common bone tumor, osteosarcoma, and its treatments. Important challenges continue to persist.

Ultra-Late Osteosarcoma Recurrences: An Analysis of 17 Cooperative Osteosarcoma Study Group Patients with a First Recurrence Detected More Than 10 Years After Primary Tumor Diagnosis

Purpose: Osteosarcoma is a typical malignancy of childhood and adolescence. Recurrences usually occur early, but rarely may arise after decades of remission. Little is known about these very late events and we set out to fill this knowledge gap. Methods: The database of the Cooperative Osteosarcoma Study Group (COSS) was searched for patients with a first recurrence of a high-grade central osteosarcoma occurring >10 years after diagnosis of the primary disease. Identified patients were analyzed for demographic, tumor-, and treatment-related factors as well as outcomes. Results: Among a total of 1,178 10-year relapse-free survivors, 17 affected patients were identified. Only five of these had a documented good response to initial chemotherapy. No presenting factor was identified to predict these very late events. Prognosis was generally very poor despite intensive multimodal therapy. Inoperability of the recurrences seems to have constituted a major limiting factor. Conclusion: Osteosarcoma patients should be followed for potential recurrences for well >10 years from initial diagnosis. Only through such an extended truly long-term follow-up and a structured transition of young patients can these be detected while they are still operable and, hence, potentially curable.

Profiling of Multiple Matrix Metalloproteinases Activities in the Progression of Osteosarcoma by Peptide Microarray-Based Fluorescence Assay on Polymer Brush-Coated Zinc Oxide Nanorod Substrate

Peptide microarray provides the ability to miniaturize, parallelize, and automate high-throughput screening substrate specificities of enzymes, profiling of multiple enzyme activities, discovery of disease biomarkers, and development of drugs. Matrix metalloproteinases (MMPs) are demonstrated as important biomarkers of tumor invasion and metastasis. Herein, a peptide microarray-based fluorescence assay is proposed to profile multiple MMPs (MMP-1, MMP-2, MMP-3, MMP-7, MMP-9, and MMP-13) activities in the culture medium of four human osteosarcoma (OS) cells and in the progression of OS by using the mouse-bearing xenograft OSs including U-2OS and Saos-2 human. This method has excellent selectivity and sensitivity, which enables to detect the activities of cellular secreted MMP-1, MMP-2, MMP-3, MMP-7, MMP-9, and MMP-13 with limit of detection downs to 10 pM, 30 pM, 113 pM, 13 pM, 93 pM, and 12 pM, respectively. Furthermore, it is demonstrated that the activity pattern of MMPs is serum closely relevant to the disease progression and type of tumor.

Evaluation of the pan-class I phosphoinositide 3-kinase (PI3K) inhibitor copanlisib in the Pediatric Preclinical Testing Consortium in vivo models of osteosarcoma

Copanlisib is a pan-class I phosphoinositide 3-kinase (PI3K) inhibitor, with activity against all four PI3K class I isoforms (PI3Kα, PI3Kβ, PI3Kγ, and PI3Kδ). Whole-genome and RNA sequencing data have revealed several PI3K aberrations in osteosarcoma tumor samples. The in vivo anticancer effects of copanlisib were assessed in a panel of six osteosarcoma models. Copanlisib induced prolonged event-free survival in five of six osteosarcoma models; however, all models demonstrated progressive disease suggesting minimal activity. While copanlisib did not result in tumor regression, more data are needed to fully explore the role of the PI3K pathway in the pathogenesis of osteosarcoma.

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.

Anticancer mechanism studies of iridium(III) complexes inhibiting osteosarcoma HOS cells proliferation

Three iridium (III) polypyridine complexes [Ir(bzq)₂(maip)](PF₆) (Ir1，bzq = benzo[h]quinoline, maip = 3-aminophenyl-1H-imidazo[4,5-f][1,10]phenanthroline), [Ir(bzq)₂(apip)](PF₆) (Ir2, apip = 2-aminophenyl-1H-imidazo[4,5-f][1,10]phenanthroline) and [Ir(bzq)₂(paip)](PF₆) (Ir3, paip = 4-aminophenyl-1H-imidazo[4,5-f][1,10]phenanthroline) were synthesized and characterized. The cytotoxic activities of the three complexes against human osteosarcoma HOS, U2OS, MG63 and normal LO2 cells were evaluated by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) method. The results showed that Ir1-3 exhibited moderate antitumor activity against HOS with IC₅₀ of 21.8 ± 0. 4 μM,10.5 ± 1.8 μM and 7.4 ± 0.4 μM, respectively. We found that Ir1-3 can effectively inhibit HOS cells growth and blocked the cell cycle at the G0/G1 phase. Further studies revealed that complexes can increase intracellular reactive oxygen species (ROS) and Ca²⁺, which accompanied by mitochondria-mediated intrinsic apoptosis pathway. In addition, autophagy was also investigated. Taken together, the complexes induce HOS apoptosis through a ROS-mediated mitochondrial dysfunction pathway and inhibition of the PI3K (phosphatidylinositol 3-kinase)/AKT (protein kinase B)/mTOR (mammalian target of rapamycin) signaling pathway. This study provides useful help for understanding the anticancer mechanism of iridium (III) complexes toward osteosarcoma treatment.

Controversies and Challenges in the Management of Osteosarcoma-an Indian Perspective

Osteosarcoma (OGS) is the most common primary bone tumor in children and adolescents which requires a multidisciplinary approach to management. Although chemotherapy and surgery can cure more than half of localized OGS cases, the unique challenges faced by resource-limited countries like India make this outcome difficult to achieve. Various questions in the management of OGS including role of high-dose methotrexate (HDMTX) in neoadjuvant setting, triplet vs doublet chemotherapy, intensification of chemotherapy based on response in setting of doublet, and indigenous prosthesis in setting of limb salvage need to be defined. Similarly, in the metastatic and recurrent setting, questions regarding intent of treatment, indications of chemotherapy, timing of surgery, and role of targeted therapies need clarification. Lack of randomized trials from India makes definite conclusions difficult, but an attempt can be made to define the best approach in the Indian scenario from available evidence. Hence, a critical review of literature from India and the West was done to define possible management approaches and highlight the lacuna for future research.

Machine learning and experimental validation to construct a metastasis-related gene signature and ceRNA network for predicting osteosarcoma prognosis

OBJECTIVE

Osteosarcoma (OS) is more common in adolescents and significantly harmful, and the survival rate is considerably low, especially in patients with metastatic OS. The identification of effective biomarkers and associated regulatory mechanisms, which predict OS occurrence and development as well as improve prognostic accuracy, will help develop more refined protocols for OS treatment.

METHODS

In this study, genes showing differential expression in metastatic and non-metastatic types of OS were identified, and the ones affecting OS prognosis were screened from among these. Following this, the functions and pathways associated with the genes were explored via enrichment analysis, and an effective predictive signature was constructed using Cox regression based on the machine learning algorithm, least absolute shrinkage and selection operator (LASSO). Next, a correlative competing endogenous RNA (ceRNA) regulatory axis was constructed after verification by bioinformatics analysis and luciferase reporter gene experiments conducted based on the prognostic signature.

RESULTS

Overall, 251 differentially expressed genes were identified and screened using bioinformatics and double luciferase reporter gene experiments. An effective prognostic signature was constructed based on 15 genes associated with OS metastasis, and upstream non-coding RNAs were identified to construct the "NBR2/miR-129-5p/FKBP11" regulatory axis based on the ceRNA networks, which helped identify candidate biomarkers for the OS clinical diagnosis and treatment, drug research, and prognostic prediction, among other applications. The findings of this study provide a novel strategy for determining the mechanism underlying OS occurrence and development and the appropriate treatment.

Renal metastasis of osteosarcoma after multiple pulmonary metastases: A case report and review of literature

Renal metastasis of osteosarcoma is a rare entity, with paucity of reported cases in the literature. We report a case of a 20-year-old gentleman who was diagnosed with right distal femur osteosarcoma, complicated with multiple pulmonary recurrences. At two-year-and-a-half interval post-treatment completion, the patient developed right flank pain and frank haematuria. Contrasted abdominal computed tomography revealed a right renal mass with calcification and perinephric haematoma. A right radical nephrectomy was undertaken and histopathological examination showed metastatic condroblastic osteosarcoma. A literature review on renal metastasis secondary to osteosarcoma was performed and we present a report and discussion of these cases.

The Critical Role of Academic Clinical Trials in Pediatric Cancer Drug Approvals: Design, Conduct, and Fit for Purpose Data for Positive Regulatory Decisions

PURPOSE

For decades, academic clinical trials consortia have collaborated to optimize outcomes for childhood cancers through evaluating incremental improvements in conventional mutimodality treatment regimes. There are now increasing opportunities to partner with industry to test new medicines in academic-sponsored trials, but these collaborative studies rarely contribute to marketing authorizations. We addressed why this is the case and sought solutions to enable academic-sponsored trials to directly contribute to the licensing of new medicines.

METHODS

Under the auspices of the multistakeholder platform ACCELERATE, we convened a working group of representatives from clinical academia, pharmaceutical industry, European Medicines Agency, US Food and Drug Administration, and patient advocacy to define the challenges and propose recommendations to facilitate academic-sponsored trial design and conduct to be aligned to both the needs of the pharmaceutical company who own the asset and the expectations of the regulatory (licensing) authorities.

RESULTS

We identified that although academic consortia have long-standing expertise to conduct robust clinical trials, there were critical gaps in knowledge, standard procedures, and resources that hindered the trial data directly contributing to marketing authorization applications. We propose a suite of recommendations focused on (1) essential documents, (2) essential data, (3) data management, and (4) trial resources, specifically aimed at enabling academic-industry partnerships to deliver an academic-sponsored trial that meets the requirements for a marketing authorization submission. These recommendations pivot around transparency in academic-industry partnerships and early engagement with regulators.

CONCLUSION

Academic sponsors and industry partners need to prospectively recognize when the planned collaborative trial could contribute to an application to marketing authorization and plan accordingly. Transparent collaboration and knowledge sharing between the partners opens an important pathway for accelerating new treatments into clinical practice for children with cancer.

Identification of ATG7 as a Regulator of Proferroptosis and Oxidative Stress in Osteosarcoma

Background

Ferroptosis has gained significant attention from oncologists as a vital outcome of oxidative stress. The aim of this study was to develop a prognostic signature that was based on the ferroptosis-related genes (FRGs) for osteosarcoma patients and explore their specific role in osteosarcoma.

Methods

The training cohort dataset was extracted from the Therapeutically Applicable Research to Generate Effective Treatments (TARGET) database. Different techniques like the univariate Cox regression, least absolute shrinkage and selection operator (LASSO) regression, multivariate Cox regression analyses, and the Kaplan-Meier (KM) survival analyses were utilized to develop a prognostic signature. Then, the intrinsic relationship between the developed gene signature and the infiltration levels of the immune cells was further investigated. An external validation dataset from the Gene Expression Omnibus (GEO) database was employed to assess the predictive ability of the developed gene signature. Subsequently, the specific function of potential FRG in affecting the oxidative stress reaction and ferroptosis of osteosarcoma cells was identified.

Results

A prognostic signature based on 5 FRGs (CBS, MUC1, ATG7, SOCS1, and PEBP1) was developed, and the patients were classified into the low- and high-risk groups (categories). High-risk patients displayed poor overall survival outcomes. The risk level was seen to be an independent risk factor for determining the prognosis of osteosarcoma patients (p < 0.001, hazard ratio: 7.457, 95% CI: 3.302-16.837). Additionally, the risk level was associated with immune function, which might affect the survival status of osteosarcoma patients. Moreover, the findings of the study indicated that the expression of ATG7 was related to the regulation of oxidative stress in osteosarcoma. Silencing the ATG7 gene promoted the proliferation and migration in osteosarcoma cells, suppressing the oxidative stress and ferroptosis process.

Conclusions

A novel FRG signature was developed in this study to predict the prognosis of osteosarcoma patients. The results indicated that ATG7 might regulate the process of oxidative stress and ferroptosis in osteosarcoma cells and could be used as a potential target to develop therapeutic strategies for treating osteosarcoma.

The Combination of Anlotinib and Gemcitabine/Docetaxel in Patients with Metastatic Osteosarcoma Who Have Failed Standard Chemotherapy

Purpose

The options for the second-line treatment of metastatic osteosarcoma are still limited. Anlotinib is a multi-kinase inhibitor which has shown promising efficacy and good tolerability in various cancer types. This retrospective study was conducted to evaluate the efficacy and safety of anlotinib combined with gemcitabine/docetaxel (GD) in patients with metastatic osteosarcoma who have failed first-line chemotherapy.

Patients and Methods

The data of patients who received anlotinib combined with GD or GD were collected. The primary endpoint was progression-free survival. Secondary endpoints included objective response rate and safety.

Results

From July 2013 to November 2020, a total of 32 patients were enrolled, 13 received anlotinib combined with GD and 19 received GD. Median PFS was 9.0 months (95% CI 6.7-39.1) in the combination group and 5.0 months (95% CI 1.2-6.7) in the chemotherapy group. ORR were 38.4% and 15.8%, DCR were 69.2% and 38.1% in the combination and chemotherapy group, respectively. The most common adverse events included fatigue (78.9% in the combination group vs 69.2% in the chemotherapy group), hypertension (46.2% vs 10.5%), diarrhea (38.5% vs 21.1%), hypothyroidism (38.5% vs 15.8%), neutropenia (23.1% vs 36.8%) and AST elevation (30.8% vs 21.1%). The most common grade 3 or worse adverse events included hand-foot reaction (7.7% vs 5.3%), hypothyroidism (15.4% vs 0), neutropenia (0 vs 10.5%).

Conclusion

The combination of anlotinib and GD showed favorable efficacy with manageable toxicities compared with GD in the second-line treatment for metastatic osteosarcoma. This combination therapy deserves further investigations in patients with osteosarcoma.

LncRNA FGD5-AS1 potentiates autophagy-associated doxorubicin resistance by regulating the miR-154-5p/WNT5A axis in osteosarcoma

Osteosarcoma is prevalent in children and adolescent. The oncogenic function of long-chain noncoding RNA (lncRNA) FGD5 antisense RNA 1 (FGD5-AS1) has been reported. However, the function of FGD5-AS1 in doxorubicin-resistance in osteosarcoma remains to be illucidated. Quantitative real-time PCR (qRT-PCR) and western blot analysis (WB) were used to measure the expression of FGD5-AS1, miR-154-5p, WNT5A and autophagy proteins. MTT assay was used to assess cell viability and transwell assay was performed to evaluate migration. A nude mouse xenograft model was developed to verify the function of FGD5-AS1 in vivo. FGD5-AS1 was upregulated in doxorubicin-resistant (DXR) osteosarcoma cells. Knockdown of FGD5-AS1 suppressed osteosarcoma cell proliferation, migration, and autophagy. FGD5-AS1 upregulated WNT5A expression via sponging miR-154-5p. Furthermore, FGD5-AS1 enhanced osteosarcoma cell chemotherapy resistance through upregulation of WNT5A by inhibiting miR-154-5p. Suppression of FGD5-AS1 significantly suppressed tumor growth in nude mice. FGD5-AS1 may promote chemoresistance through WNT5A-induced autophagy by sponging miR-154-5p in osteosarcoma cells.

A novel necroptosis-related lncRNAs signature effectively predicts the prognosis for osteosarcoma and is associated with immunity

Background: Necroptosis is closely related to tumorigenesis and development. Accumulating evidence has revealed that long non-coding RNAs (lncRNAs) are also central players in osteosarcoma (OS). However, the role of necroptosis-related lncRNAs in OS remains unclear. In the present study, we aim to craft a prognostic signature based on necroptosis-related lncRNAs to improve the OS prognosis prediction.

Methods: The signature based on necroptosis-related lncRNAs was discovered using univariate Cox, least absolute shrinkage and selection operator (LASSO), and multivariate Cox regression analysis. The prognosis efficiency of the signature was then estimated by employing various bioinformatics methods. Subsequently, immunological analysis and Gene Set Enrichment Analysis (GSEA) were used to explore the association between necroptosis-related lncRNAs with clinical outcomes and immune status. More importantly, several necroptosis-related lncRNAs were validated with RT-qPCR.

Results: Consequently, a novel prognosis signature was successfully constructed based on eight necroptosis-related lncRNAs. Meanwhile, the novel necroptosis-related lncRNAs model could distribute OS patients into two risk groups with a stable and accurate predictive ability. Additionally, the GSEA and immune analysis revealed that the necroptosis-related lncRNAs signature affects the development and prognosis of OS by regulating the immune status. The necroptosis-related lncRNA signature was closely correlated with multiple anticancer agent susceptibility. Moreover, the RT-qPCR results indicated several necroptosis-related lncRNAs were significantly differently expressed in osteosarcoma and osteoblast cell lines.

Conclusion: In this summary, a novel prognostic signature integrating necroptosis-related lncRNAs was firstly constructed and could accurately predict the prognosis of OS. This study may increase the predicted value and guide the personalized chemotherapy treatment for OS.