Zoledronate in combination with chemotherapy and surgery to treat osteosarcoma (OS2006): a randomised, multicentre, open-label, phase 3 trial

Microenvironment matters: insights from the FOSTER consortium on microenvironment-driven approaches to osteosarcoma therapy

Osteosarcoma (OS), a prevalent malignant bone tumor, has seen limited progress in treatment efficacy and patient outcomes over decades. Recent insights into the tumor microenvironment (TME) have revealed its crucial role in tumor progression and therapeutic resistance, particularly in OS. This review offers a comprehensive exploration of the OS microenvironment, meticulously dissecting its crucial components: the mesenchymal stromal TME, the immune microenvironment, hypoxia-induced adaptations, and the impact of the physical microenvironment. By demonstrating how these elements collectively drive tumor proliferation, immune evasion, and invasion, this review explores the intricate molecular and cellular dynamics at play. Furthermore, innovative approaches targeting the OS microenvironment, such as immunotherapies, are presented. This review highlights the importance of the TME in OS progression and its potential as a source of novel therapeutic strategies, offering new hope for improved patient outcomes.

Methotrexate, Doxorubicin, and Cisplatin Versus Methotrexate, Doxorubicin, and Cisplatin + Ifosfamide in Poor Responders to Preoperative Chemotherapy for Newly Diagnosed High-Grade Osteosarcoma (JCOG0905): A Multicenter, Open-Label, Randomized Trial

PURPOSE

Our previous NECO phase II studies on high-grade osteosarcoma suggested that administering ifosfamide (IF; 16 g/m2 [4g/m2 once on day 1, then 2g/m2 once on days 2-7] × six) to patients showing a poor response (PrRsp) to preoperative chemotherapy with methotrexate, doxorubicin, and cisplatin (MAP) improves their prognoses. In this Japan Clinical Oncology Group (JCOG) study, JCOG0905, we aimed to investigate the efficacy and safety of IF in patients with PrRsp.

METHODS

JCOG0905 is a multicenter, open-label, multi-institutional, randomized trial. Eligible patients (50 years and younger) had resectable, high-grade osteosarcoma (stage II or III, Union for International Cancer Control TNM) of the extremities, limb girdles, and thoracic wall. After two MAP cycles and tumor resection, patients with PrRsp were randomly assigned to either the MAP or MAP plus 15 g/m2 (3g/m2 once daily on days 1-5) × six IF (MAP + IF [MAPIF]) group. The primary end point was disease-free survival (DFS); secondary end points were overall survival (OS) and safety. The planned sample size was 100 patients with a one-sided α of .1 and a power of 0.7, assuming a 3-year DFS of 50% and 65% for MAP and MAPIF, respectively. This trial is registered with the Japan Registry of Clinical Trials (jRCT; jRCTs031180126).

RESULTS

Of the 287 patients registered between February 2010 and August 2020, 51 and 52 patients with PrRsp were assigned to the MAP and MAPIF groups, respectively. As of March 2022, DFS did not differ between groups (hazard ratio [HR], 1.05 [95% CI, 0.55 to 1.98]) and OS was numerically inferior in the MAPIF group (HR, 1.48 [95% CI, 0.68 to 3.22]). Nine and zero patients in the MAPIF and MAP groups discontinued treatment because of adverse events, respectively.

CONCLUSION

Evidence from JCOG0905 does not support the addition of IF for patients with PrRsp.

PD-1 interactome in osteosarcoma: identification of a novel PD-1/AXL interaction conserved between humans and dogs

The PD-1/PDL-1 immune checkpoint inhibitors revolutionized cancer treatment, yet osteosarcoma remains a therapeutic challenge. In some types of cancer, PD-1 receptor is not solely expressed by immune cells but also by cancer cells, acting either as a tumor suppressor or promoter. While well-characterized in immune cells, little is known about the role and interactome of the PD-1 pathway in cancer. We investigated PD-1 expression in human osteosarcoma cells and studied PD-1 protein-protein interactions in cancer. Using U2OS cells as a model, we confirmed PD-1 expression by western blotting and characterized its intracellular as well as surface localization through flow cytometry and immunofluorescence. High-throughput analysis of PD-1 interacting proteins was performed using a pull-down assay and quantitative mass spectrometry proteomic analysis. For validation and molecular modeling, we selected tyrosine kinase receptor AXL-a recently reported cancer therapeutic target. We confirmed the PD-1/AXL interaction by immunoblotting and proximity ligation assay (PLA). Molecular dynamics (MD) simulations uncovered binding affinities and domain-specific interactions between extracellular (ECD) and intracellular (ICD) domains of PD-1 and AXL. ECD complexes exhibited strong binding affinity, further increasing for the ICD complexes, emphasizing the role of ICDs in the interaction. PD-1 phosphorylation mutant variants (Y223F and Y248F) did not disrupt the interaction but displayed varying strengths and binding affinities. Using bemcentinib, a selective AXL inhibitor, we observed reduced binding affinity in the PD-1/AXL interaction, although it was not abrogated. To facilitate the future translation of this finding into clinical application, we sought to validate the interaction in canine osteosarcoma. Osteosarcoma spontaneously occurs at significantly higher frequency in dogs and shares close genetic and pathological similarities with humans. We confirmed endogenous expression of PD-1 and AXL in canine osteosarcoma cells, with PD-1/AXL interaction preserved in the dog cells. Also, the interacting residues remain conserved in both species, indicating an important biological function of the interaction. Our study shed light on the molecular basis of the PD-1/AXL interaction with the implication for its conservation across species, providing a foundation for future research aimed at improving immunotherapy strategies and developing novel therapeutic approaches.

Li-Fraumeni-associated osteosarcomas: The French experience

PURPOSE

Describe clinical characteristics and outcome of Li-Fraumeni syndrome (LFS)-associated osteosarcomas.

METHODS

TP53 germline pathogenic/likely pathogenic variant carriers diagnosed with osteosarcoma in France between 1980 and 2019 were identified via the French Li-Fraumeni database at Rouen University Hospital. Sixty-five osteosarcomas in 52 patients with available clinical and histological data were included. The main clinical characteristics were compared with data from National Cancer Institute's SEER (Surveillance, Epidemiology, and End Results) for patients of the same age group.

RESULTS

Median age at first osteosarcoma diagnosis was 13.7 years (range: 5.9-36.7). Compared to unselected osteosarcomas, LFS-associated osteosarcomas occurred more frequently in patients less than 10 years of age (23% vs. 9%), and when compared with osteosarcomas in patients less than 25 years were characterized by an excess of axial (16% vs. 10%) and jaw sites (15% vs. 3%) and histology with predominant chondroblastic component and periosteal subtypes (17% vs. 1%). Metastases incidence (25%) was as expected in osteosarcomas. After the first osteosarcoma treatment, the rate of good histologic response (62%) and the 5-year progression-free survival (55%, 95% confidence interval [CI]: 42.6-71.1) were as expected in unselected series of osteosarcomas, whereas the 5-year event-free survival was 36.5% [95% CI: 25.3-52.7] due to the high incidence of second malignancies reaching a 10-year cumulative risk of 43.4% [95% CI: 28.5-57.5].

CONCLUSION

In osteosarcoma, young age at diagnosis, axial and jaw sites, histology with periosteal or chondroblastic subtype, and synchronous multifocal tumors should prompt suspicion of a germline TP53 mutation. Standard treatments are effective, but multiple malignancies impair prognosis. Early recognition of these patients is crucial for tailored therapy and follow-up.

Bayesian unsupervised clustering identifies clinically relevant osteosarcoma subtypes

Identification of cancer subtypes is a critical step for developing precision medicine. Most cancer subtyping is based on the analysis of RNA sequencing (RNA-seq) data from patient cohorts using unsupervised machine learning methods such as hierarchical cluster analysis, but these computational approaches disregard the heterogeneous composition of individual cancer samples. Here, we used a more sophisticated unsupervised Bayesian model termed latent process decomposition (LPD), which handles individual cancer sample heterogeneity and deconvolutes the structure of transcriptome data to provide clinically relevant information. The work was performed on the pediatric tumor osteosarcoma, which is a prototypical model for a rare and heterogeneous cancer. The LPD model detected three osteosarcoma subtypes. The subtype with the poorest prognosis was validated using independent patient datasets. This new stratification framework will be important for more accurate diagnostic labeling, expediting precision medicine, and improving clinical trial success. Our results emphasize the importance of using more sophisticated machine learning approaches (and for teaching deep learning and artificial intelligence) for RNA-seq data analysis, which may assist drug targeting and clinical management.

Osteosarcoma through the Lens of Bone Development, Signaling, and Microenvironment

In this work, we review the multifaceted connections between osteosarcoma (OS) biology and normal bone development. We summarize and critically analyze existing research, highlighting key areas that merit further exploration. The review addresses several topics in OS biology and their interplay with normal bone development processes, including OS cell of origin, genomics, tumor microenvironment, and metastasis. We examine the potential cellular origins of OS and how their roles in normal bone growth may contribute to OS pathogenesis. We survey the genomic landscape of OS, highlighting the developmental roles of genes frequently altered in OS. We then discuss the OS microenvironment, emphasizing the transformation of the bone niche in OS to facilitate tumor growth and metastasis. The role of stromal and immune cells is examined, including their impact on tumor progression and therapeutic response. We further provide insights into potential development-informed opportunities for novel therapeutic strategies.

Zoledronic acid enhances tumor growth and metastatic spread in a mouse model of jaw osteosarcoma

OBJECTIVES

Investigation of the therapeutic effect of zoledronic acid (ZA) in a preclinical model of jaw osteosarcoma (JO).

MATERIALS AND METHODS

The effect of 100 μg/kg ZA administered twice a week was assessed in a xenogenic mouse model of JO. The clinical (tumor growth, development of lung metastasis), radiological (bone microarchitecture by micro-CT analysis), and molecular and immunohistochemical (TRAP, RANK/RANKL, VEGF, and CD146) parameters were investigated.

RESULTS

Animals receiving ZA exhibited an increased tumor volume compared with nontreated animals (71.3 ± 14.3 mm3 vs. 51.9 ± 19.9 mm3 at D14, respectively; p = 0.06) as well as increased numbers of lung metastases (mean 4.88 ± 4.45 vs. 0.50 ± 1.07 metastases, respectively; p = 0.02). ZA protected mandibular bone against tumor osteolysis (mean bone volume of 12.81 ± 0.53 mm3 in the ZA group vs. 11.55 ± 1.18 mm3 in the control group; p = 0.01). ZA induced a nonsignificant decrease in mRNA expression of the osteoclastic marker TRAP and an increase in RANK/RANKL bone remodeling markers.

CONCLUSION

The use of bisphosphonates in the therapeutic strategy for JO should be further explored, as should the role of bone resorption in the pathophysiology of the disease.

Metallocompounds as anticancer agents against osteosarcoma

Metallocompounds are a class of anticancer compounds largely used in the treatment of several types of solid tumors, including bone cancer. Osteosarcoma (OS) is a primary malignant bone tumor that frequently affects children, adolescents and young adults. It is a very invasive type of tumor, so ∼40% of patients develop distant metastases, showing elevated mortality rates. In this review, we present an outline of the chemistry and antitumor properties of metal-based compounds in preclinical (in vitro and in vivo) and clinical OS models, focusing on the relationship between structure-activity, molecular targets and the study of the mechanism of action involved in metallocompound anticancer activity.

Impact of age on safety of Busulfan-Melphalan followed by autologous hematopoietic stem-cell transplantation versus standard chemotherapy in the patients of the EURO-E.W.I.N.G. 99 and Ewing 2008 clinical trials

INTRODUCTION

Ewing sarcoma (ES), is a rare cancer affecting children, adolescents and adults. After VIDE (vincristine-ifosfamide-doxorobucin-etoposide) induction chemotherapy, Busulfan-Melphalan (BuMel) high-dose chemotherapy followed by autologous hematopoietic stem cells transplantation improved outcomes in unfavourable localized ES, but with more toxicities than conventional chemotherapy (VAI: Vincristine-dactinomycin-Ifosfamide). We evaluated whether the risk of acute toxicity associated with BuMel compared to VAI varied according to age in patients recruited in the R2Loc and R2Pulm randomised trials of the Euro-E.W.I.N.G.99 and Ewing-2008 trials.

METHODS

We included patients with a localized high-risk disease, or pulmonary or pleural metastasis. We analysed the risk of severe toxicity according to randomised treatment group (VAI versus BuMel) and age group (<12 years, 12-17 years, 18-24 years, ≥25 years). We evaluated the heterogeneity of treatment effects by age group using interaction terms in logistic multivariable models.

RESULTS

The analysis included 243 patients treated with VAI and 205 with BuMel. Overall, BuMel was associated with a higher risk of severe acute toxicity than VAI particularly haematological, gastrointestinal, liver, sinusoidal occlusive syndrome, and infections. Severe haematological toxicity and lower general condition were significantly more frequent in younger patients, whatever treatment. We did not observe any significant heterogeneity in terms of the excess risk of severe toxicities associated with BuMel compared to VAI according to age group.

CONCLUSION

The excess of acute toxicity associated with BuMel compared to VAI does not vary significantly with age, suggesting the feasibility of BuMel across all age groups.

Intratumoral Heterogeneity Assessment of the Extracellular Bone Matrix and Immune Microenvironment in Osteosarcoma Using Digital Imaging to Predict Therapeutic Response

The assessment of chemotherapy response in osteosarcoma (OS) based on the average percentage of viable cells is limited, as it overlooks the spatial heterogeneity of tumor cell response (foci of resistant cells), immune microenvironment, and bone microarchitecture. Despite the resulting positive classification for response to chemotherapy, some patients experience early metastatic recurrence, demonstrating that our conventional tools for evaluating treatment response are insufficient. We studied the interactions between tumor cells, immune cells (lymphocytes, histiocytes, and osteoclasts), and bone extracellular matrix (ECM) in 18 surgical resection samples of OS using multiplex and conventional immunohistochemistry (IHC: CD8, CD163, CD68, and SATB2), combined with multiscale characterization approaches in territories of good and poor response (GRT/PRT) to treatment. GRT and PRT were defined as subregions with <10% and ≥10% of viable tumor cells, respectively. Local correlations between bone ECM porosity and density of immune cells were assessed in these territories. Immune cell density was then correlated to overall patient survival. Two patterns were identified for histiocytes and osteoclasts. In poor responder patients, CD68 osteoclast density exceeded that of CD163 histiocytes but was not related to bone ECM load. Conversely, in good responder patients, CD163 histiocytes were more numerous than CD68 osteoclasts. For both of them, a significant negative local correlation with bone ECM porosity was found (P < .01). Moreover, in PRT, multinucleated osteoclasts were rounded and intermingled with tumor cells, whereas in GRT, they were elongated and found in close contact with bone trabeculae. CD8 levels were always low in metastatic patients, and those initially considered good responders rapidly died from their disease. The specific recruitment of histiocytes and osteoclasts within the bone ECM, and the level of CD8 represent new features of OS response to treatment. The associated prognostic signatures should be integrated into the therapeutic stratification algorithm of patients after surgery.

Camrelizumab in combination with doxorubicin, cisplatin, ifosfamide, and methotrexate in neoadjuvant treatment of resectable osteosarcoma: A prospective, single-arm, exploratory phase II trial

BACKGROUND

The poor overall survival of osteosarcoma (OS) underscores the need to explore new therapeutic avenues. Tumor necrosis rate (TNR) after neoadjuvant chemotherapy predicts prognosis.

AIMS

The study was to investigate safety and activity of neoadjuvant chemotherapy with camrelizumab (a humanized antibody against PD-1) in patients with resectable OS.

MATERIALS & METHODS

We conducted a prospective, single-arm, exploratory phase II trial in OS patients. Eligible patients received camrelizumab combined with doxorubicin or liposomal doxorubicin, cisplatin, methotrexate, ifosfamide with mesna. Surgery was performed 12-14 days after neoadjuvant therapy and adjuvant therapy starting 2-3 weeks postoperatively. The primary endpoint was the rate of good tumor necrosis (TNR ≥90%) after neoadjuvant therapy, and the secondary outcomes were safety, 2-year progression free survival and 2-year overall survival.

RESULTS

Seventy-five patients were recruited to the study. Subsequently, 64 patients completed neoadjuvant therapy and underwent surgery. Thirty-one patients (48.4%) have a good TNR to neoadjuvant therapy. With a median follow-up of 22.4 months (range 2.2-44.9 months), the estimated 2-year PFS was 69.6% and the estimated 2-year overall survival was 89.4%. Grade 3 or 4 treatment-related adverse events were noticed in 62.7% of the patients. Frequent grade 3 or 4 adverse events were decreased platelet count (45.3%), decreased white blood cell count (36%). No immune-related serious adverse events were observed.

DISCUSSION

Our study had limitations. First, it was limited by its non-randomized design. Besides, stromal tumor-infiltrating lymphocytes was comprehensively analyzed in this study.

CONCLUSIONS

This study demonstrated that amrelizumab combined with adriamycin, cisplatin, methotrexate, and ifosfamide in the neoadjuvant treatment of resectable OS was safe and tolerable. This combined therapeutic strategy may not increase TNR, but the long-term survival benefit remains to be followed up.

Long term survival in adult osteosarcoma patients treated with a two-drug regimen: Final results of the OSAD93 phase II study of the FSG-GETO

RATIONALE

We report a phase II trial (OSAD93) testing CDDP with ifosfamide (IFO), without doxorubicin in neoadjuvant phase, in adult osteosarcoma with a 25 years follow-up.

PATIENTS AND METHODS

This is a multicentric phase II study of neoadjuvant chemotherapy with IFO and CDDP in localized high-grade osteosarcoma of patients. Patients received 4 pre-operative courses of IFO 9 g/m2 and CDDP 100 mg/m2 on day 4 (SHOC regimen), followed by local treatment. Doxorubicin was added post-operatively (HOCA regimen) in patients with > 10 % residual tumor cells. A Good Histological Response (GHR), ie ≤ 10 % residual tumor cells in > 30 % of patients, was the primary objective. Disease-free survival (DFS), overall survival (OS) and toxicity were secondary objectives.

RESULTS

From Jan 1994 to Jun 1998, 60 patients were included. Median age was 27 (range: 16-63). Primary tumor sites were limbs (76 %), trunk, head or neck (24 %). After neoadjuvant SHOC, grade 3-4 and febrile neutropenia, thrombopenia, and re-hospitalization occurred in 58 %, 17 %, 17 % and 22 % of SHOC courses and in 76 %, 28 %, 47 %, 47 % of HOCA courses, respectively. GHR was obtained in 16/60 (27.5 %) patients. With a median follow-up of 322 months, the DFS and OS were 51.8 % and 64.4 % at 5 years. At 10 years, DFS and OS were 49.9 % and 64.4 %. At 25 years, DFS and OS were 47.8 % and 55.9 %. No long-term cardiac toxicity was observed. Three patients developed a second malignancy (one fatal) after 300 months.

CONCLUSION

Though the primary endpoint of OSAD93 was not met, this pre-operative doxorubicin-free regimen led to excellent long-term survival with limited toxicity in localized osteosarcoma.

Machine Learning versus Cox Models for Predicting Overall Survival in Patients with Osteosarcoma: A Retrospective Analysis of the EURAMOS-1 Clinical Trial Data

Since the mid-1980s, there has been little progress in improving survival of patients diagnosed with osteosarcoma. Survival prediction models play a key role in clinical decision-making, guiding healthcare professionals in tailoring treatment strategies based on individual patient risks. The increasing interest of the medical community in using machine learning (ML) for predicting survival has sparked an ongoing debate on the value of ML techniques versus more traditional statistical modelling (SM) approaches. This study investigates the use of SM versus ML methods in predicting overall survival (OS) using osteosarcoma data from the EURAMOS-1 clinical trial (NCT00134030). The well-established Cox proportional hazard model is compared to the extended Cox model that includes time-varying effects, and to the ML methods random survival forests and survival neural networks. The impact of eight variables on OS predictions is explored. Results are compared on different model performance metrics, variable importance, and patient-specific predictions. The article provides comprehensive insights to aid healthcare researchers in evaluating diverse survival prediction models for low-dimensional clinical data.

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.

Payload-delivering engineered γδ T cells display enhanced cytotoxicity, persistence, and efficacy in preclinical models of osteosarcoma

T cell-based cancer immunotherapy has typically relied on membrane-bound cytotoxicity enhancers such as chimeric antigen receptors expressed in autologous αβ T cells. These approaches are limited by tonic signaling of synthetic constructs and costs associated with manufacturing. γδ T cells are an emerging alternative for cellular therapy, having innate antitumor activity, potent antibody-dependent cellular cytotoxicity, and minimal alloreactivity. We present an immunotherapeutic platform technology built around the innate properties of the Vγ9Vδ2 T cell, harnessing specific characteristics of this cell type and offering an allocompatible cellular therapy that recruits bystander immunity. We engineered γδ T cells to secrete synthetic tumor-targeting opsonins in the form of an scFv-Fc fusion protein and a mitogenic IL-15Rα-IL-15 fusion protein (stIL15). Using GD2 as a model antigen, we show that GD2-specific opsonin-secreting Vγ9Vδ2 T cells (stIL15-OPS-γδ T cells) have enhanced cytotoxicity and promote bystander activity of other lymphoid and myeloid cells. Secretion of stIL-15 abrogated the need for exogenous cytokine supplementation and further mediated activation of bystander natural killer cells. Compared with unmodified γδ T cells, stIL15-OPS-γδ T cells exhibited superior in vivo control of subcutaneous tumors and persistence in the blood. Moreover, stIL15-OPS-γδ T cells were efficacious against patient-derived osteosarcomas in animal models and in vitro, where efficacy could be boosted with the addition of zoledronic acid. Together, the data identify stIL15-OPS-γδ T cells as a candidate allogeneic cell therapy platform combining direct cytolysis with bystander activation to promote tumor control.

Biomechanical Aspects in Bone Tumor Engineering

In the past decades, anticancer drug development brought the field of tumor engineering to a new level by the need of robust test systems. Simulating tumor microenvironment in vitro remains a challenge, and osteosarcoma-the most common primary bone cancer-is no exception. The growing evidence points to the inevitable connection between biomechanical stimuli and tumor chemosensitivity and aggressiveness, thus making this component of the microenvironment a mandatory requirement to the developed models. In this review, we addressed the question: is the "in vivo - in vitro" gap in osteosarcoma engineering bridged from the perspective of biomechanical stimuli? The most notable biomechanical cues in the tumor cell microenvironment are observed and compared in the contexts of in vivo conditions and engineered three-dimensional in vitro models. Impact statement The importance of biomechanical stimuli in three-dimensional in vitro models for drug testing is becoming more pronounced nowadays. This review might assist in understanding the key players of the biophysical environment of primary bone cancer and the current state of bone tumor engineering from this perspective.

An evaluation of the combination effect of zoledronate and chemotherapeutic agents in canine osteosarcoma cells

Introduction

Osteosarcoma (OSA) is an aggressive form of bone cancer in both dogs and humans. The treatment options for metastatic (stage III) OSA are currently limited and the prognosis is poor. Zoledronate, a second generation amino-bisphosphonate, is commonly used for palliation of cancer induced bone pain. Zoledronate has also demonstrated anti-cancer properties and possibly enhances the cytotoxicity of doxorubicin in a canine histiocytosis cell line and human prostatic cancer cell line. The goal of this study was to evaluate the combination effect of zoledronate and various chemotherapeutic drugs in canine OSA cells.

Methods

Canine OSA cell line (D17), cells from two canine primary OSAs, and MDCK, a canine kidney cell line, were used to evaluate the therapeutic potential of these drugs. Carboplatin, doxorubicin, vinorelbine, toceranib, and isophosphoramide mustard (active metabolite of ifosfamide) were used as chemotherapeutic agents. First, cells were treated with either zoledronate or chemotherapy drug alone for 72 hours. Cell viability was assessed using CellTiter Glo and IC5, IC10, IC20, and IC50 were calculated. Second, cells were treated with a combination of zoledronate and each chemotherapeutic agent at their IC5, IC10, IC20, and IC50 concentrations. After 72 hours, cell viability was assessed by CellTiter Glo.

Results and discussion

Zoledronate, carboplatin, doxorubicin, vinorelbine, and isophosphoramide mustard showed concentration dependent decrease in cell viability. Toceranib showed decreased cell viability only at higher concentrations. When zoledronate was used in combination with chemotherapy drugs, while it showed potential synergistic effects with toceranib, potential antagonistic effects with vinorelbine and isophosphoramide mustard were observed. However, the results differed by cell line and thus, further evaluation is warranted to understand the exact mechanism of action.

Nonsyndromic Craniofacial Disorders

We describe the investigation and management of select pediatric craniofacial disorders their recent advances. Positional plagiocephaly: The incidence of positional plagiocephaly has increased since the institution of the "safe to sleep" campaign to reduce sudden infant death syndrome. Positional plagiocephaly may be associated with underlying developmental delay. Nonsyndromic craniosynostosis: Treatment of nonsyndromic craniosynostosis depends on the age of the patient and the suture involved. Pediatric skull lesions: Management of skull lesions depends on histologic diagnosis. Some benign skull lesions are managed conservatively, whereas erosive and malignant lesions may require surgical excision, radiotherapy, chemotherapy, or multimodality treatment.

ctDNA quantification improves estimation of outcomes in patients with high-grade osteosarcoma: a translational study from the OS2006 trial

BACKGROUND

Osteosarcoma stratification relies on clinical parameters and histological response. We developed a new personalized stratification using less invasive circulating tumor DNA (ctDNA) quantification.

PATIENTS AND METHODS

Plasma from patients homogeneously treated in the prospective protocol OS2006, at diagnosis, before surgery and end of treatment, were sequenced using low-passage whole-genome sequencing (lpWGS) for copy number alteration detection. We developed a prediction tool including ctDNA quantification and known clinical parameters to estimate patients' individual risk of event.

RESULTS

ctDNA quantification at diagnosis (diagCPA) was evaluated for 183 patients of the protocol OS2006. diagCPA as a continuous variable was a major prognostic factor, independent of other clinical parameters, including metastatic status [diagCPA hazard ratio (HR) = 3.5, P = 0.002 and 3.51, P = 0.012, for progression-free survival (PFS) and overall survival (OS)]. At the time of surgery and until the end of treatment, diagCPA was also a major prognostic factor independent of histological response (diagCPA HR = 9.2, P < 0.001 and 11.6, P < 0.001, for PFS and OS). Therefore, the addition of diagCPA to metastatic status at diagnosis or poor histological response after surgery improved the prognostic stratification of patients with osteosarcoma. We developed the prediction tool PRONOS to generate individual risk estimations, showing great performance ctDNA quantification at the time of surgery and the end of treatment still required improvement to overcome the low sensitivity of lpWGS and to enable the follow-up of disease progression.

CONCLUSIONS

The addition of ctDNA quantification to known risk factors improves the estimation of prognosis calculated by our prediction tool PRONOS. To confirm its value, an external validation in the Sarcoma 13 trial is underway.

Zoledronic Acid Add-on Therapy for Standard-Risk Ewing Sarcoma Patients in the Ewing 2008R1 Trial

PURPOSE

The phase III, open-label, prospective, multicenter, randomized Ewing 2008R1 trial (EudraCT2008-003658-13) was conducted in 12 countries to evaluate the effect of zoledronic acid (ZOL) maintenance therapy compared with no add-on regarding event-free survival (EFS, primary endpoint) and overall survival (OS) in standard-risk Ewing sarcoma (EWS).

PATIENTS AND METHODS

Eligible patients had localized EWS with either good histologic response to induction chemotherapy and/or small tumors (<200 mL). Patients received six cycles of VIDE induction and eight cycles of VAI (male) or eight cycles of VAC (female) consolidation. ZOL treatment started parallel to the sixth consolidation cycle. Randomization was stratified by tumor site (pelvis/other). The two-sided adaptive inverse-normal four-stage design (planned sample size 448 patients, significance level 5%, power 80%) was changed after the first interim analysis using the Müller-Schäfer method.

RESULTS

Between April 2010 and November 2018, 284 patients were randomized (142 ZOL/142 no add-on). With a median follow-up of 3.9 years, EFS was not significantly different between ZOL and no add-on group in the adaptive design (HR, 0.74; 95% CI, 0.43-1.28, P = 0.27, intention-to-treat). Three-year EFS rates were 84.0% (95% CI, 77.7%-90.8%) for ZOL vs. 81.7% (95% CI, 75.2%-88.8%) for no add-on. Results were similar in the per-protocol collective. OS was not different between groups. The 3-year OS was 92.8% (95% CI, 88.4%-97.5%) for ZOL and 94.6% (95% CI, 90.9%-98.6%) for no add-on. Noticeable more renal, neurologic, and gastrointestinal toxicities were observed for ZOL (P < 0.05). Severe renal toxicities occurred more often in the ZOL arm (P = 0.003).

CONCLUSIONS

In patients with standard-risk localized EWS, there is no additional benefit from maintenance treatment with ZOL.

Effects of zoledronic acid on osteosarcoma progression and metastasis: systematic review and meta-analysis

Zoledronic Acid (ZA) has been shown to inhibit Osteosarcoma (OSA) progression in preclinical studies. However, the use of ZA as an intervention for OSA treatment and management remains controversial. A systematic review and meta-analysis of randomized-controlled trials comparing the use of ZA with standard treatment vs. standard treatment alone for OSA patients after resection was conducted. Primary outcomes assessed event-free survival (EFS) and overall survival (OS) rates, while secondary outcomes assessed impact of ZA on metastatic spread, histological response and adverse events occurrence. A literature search was conducted using EMBASE, MEDLINE, and the Cochrane Central Register of Controlled Trials. The Cochrane risk of bias tool (version 2) was used to assess trial quality. RevMan v5.4 was used for the meta-analysis. The between-trial heterogeneity was assessed using the Chi2 test and the I2 statistic and the GRADE methodology was utilized to assess certainty of evidence. Two studies were considered eligible for qualitative synthesis and meta-analysis. ZA had no benefit on EFS (HR, 0.95; 95% CI, 0.48-1.88; p-value 0.88), however, when compared to standard treatment it reduced OS (HR, 1.98; 95% CI, 1.49-2.64; p-value < 0.00001). ZA did not deter lung metastasis (RR, 2.56; 95% CI, 0.35-18.60; p-value 0.35), and neither did it increase good histological response (RR, 0.97; 95% CI, 0.90-1.05; p-value 0.48). ZA treatment was associated with higher risk of adverse events. Based on existing data, the use of ZA as adjuvant therapy is not recommended for the treatment of OSA patients.

A TLR4 Agonist Induces Osteosarcoma Regression by Inducing an Antitumor Immune Response and Reprogramming M2 Macrophages to M1 Macrophages

Osteosarcoma (OsA) has limited treatment options and stagnant 5-year survival rates. Its immune microenvironment is characterized by a predominance of tumor-associated macrophages (TAMs), whose role in OsA progression remain unclear. Nevertheless, immunotherapies aiming to modulate macrophages activation and polarization could be of interest for OsA treatment. In this study, the antitumor effect of a liposome-encapsulated chemically detoxified lipopolysaccharide (Lipo-MP-LPS) was evaluated as a therapeutic approach for OsA. Lipo-MP-LPS is a toll-like receptor 4 (TLR4) agonist sufficiently safe and soluble to be IV administered at effective doses. Lipo-MP-LPS exhibited a significant antitumor response, with tumor regression in 50% of treated animals and delayed tumor progression in the remaining 50%. The agent inhibited tumor growth by 75%, surpassing the efficacy of other immunotherapies tested in OsA. Lipo-MP-LPS modulated OsA's immune microenvironment by favoring the transition of M2 macrophages to M1 phenotype, creating a proinflammatory milieu and facilitating T-cell recruitment and antitumor immune response. Overall, the study demonstrates the potent antitumor effect of Lipo-MP-LPS as monotherapy in an OsA immunocompetent model. Reprogramming macrophages and altering the immune microenvironment likely contribute to the observed tumor control. These findings support the concept of immunomodulatory approaches for the treatment of highly resistant tumors like OsA.

Survival benefits and challenges of adjuvant chemotherapy for high-grade osteosarcoma: a population-based study

BACKGROUND

Osteosarcoma is the most prevalent primary malignant bone tumor. The primary treatment for osteosarcoma is a combination of chemotherapy and surgery. However, there has been no recent progress in the role of chemotherapy in improving the long-term survival of osteosarcoma patients. This study aims to analyze the factors that affect chemotherapy in patients with osteosarcoma and explore the challenges and survival benefits of chemotherapy.

METHODS

Patient data were downloaded from The Surveillance, Epidemiology, and End Results database. Univariable and multivariable logistic regressions were used to analyze the factors affecting patients receiving chemotherapy. Kaplan-Meier (K-M) curve was used to analyze the survival benefit of chemotherapy in patients with osteosarcoma. Finally, we used annual percentage change (APC) to evaluate the annual changes in chemotherapy treatment rates and trends in 5-year survival rates in osteosarcoma patients.

RESULTS

A total of 2157 osteosarcoma patients were included, of which 1887 patients received chemotherapy. Factors affecting patients receiving chemotherapy included age, primary tumor site, tumor size, N stage, M stage, and surgery. The K-M curve showed that older patients could benefit significantly from chemotherapy. The APC results showed no significant change in the chemotherapy treatment rate and 5-year overall survival rate of osteosarcoma patients.

CONCLUSION

Chemotherapy is an irreplaceable treatment for patients with osteosarcoma. However, in recent years, there has been no significant progress in chemotherapy for osteosarcoma, and the long-term survival of patients has not improved significantly. New chemotherapeutic drugs or drug delivery systems are urgently needed to improve the prognosis of patients with osteosarcoma.

Advances in Osteosarcoma

PURPOSE OF REVIEW

This article gives a brief overview of the most recent developments in osteosarcoma treatment, including targeting of signaling pathways, immune checkpoint inhibitors, drug delivery strategies as single or combined approaches, and the identification of new therapeutic targets to face this highly heterogeneous disease.

RECENT FINDINGS

Osteosarcoma is one of the most common primary malignant bone tumors in children and young adults, with a high risk of bone and lung metastases and a 5-year survival rate around 70% in the absence of metastases and 30% if metastases are detected at the time of diagnosis. Despite the novel advances in neoadjuvant chemotherapy, the effective treatment for osteosarcoma has not improved in the last 4 decades. The emergence of immunotherapy has transformed the paradigm of treatment, focusing therapeutic strategies on the potential of immune checkpoint inhibitors. However, the most recent clinical trials show a slight improvement over the conventional polychemotherapy scheme. The tumor microenvironment plays a crucial role in the pathogenesis of osteosarcoma by controlling the tumor growth, the metastatic process and the drug resistance and paved the way of new therapeutic options that must be validated by accurate pre-clinical studies and clinical trials.

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.

Targeting strategies for bone diseases: signaling pathways and clinical studies

Since the proposal of Paul Ehrlich's magic bullet concept over 100 years ago, tremendous advances have occurred in targeted therapy. From the initial selective antibody, antitoxin to targeted drug delivery that emerged in the past decades, more precise therapeutic efficacy is realized in specific pathological sites of clinical diseases. As a highly pyknotic mineralized tissue with lessened blood flow, bone is characterized by a complex remodeling and homeostatic regulation mechanism, which makes drug therapy for skeletal diseases more challenging than other tissues. Bone-targeted therapy has been considered a promising therapeutic approach for handling such drawbacks. With the deepening understanding of bone biology, improvements in some established bone-targeted drugs and novel therapeutic targets for drugs and deliveries have emerged on the horizon. In this review, we provide a panoramic summary of recent advances in therapeutic strategies based on bone targeting. We highlight targeting strategies based on bone structure and remodeling biology. For bone-targeted therapeutic agents, in addition to improvements of the classic denosumab, romosozumab, and PTH1R ligands, potential regulation of the remodeling process targeting other key membrane expressions, cellular crosstalk, and gene expression, of all bone cells has been exploited. For bone-targeted drug delivery, different delivery strategies targeting bone matrix, bone marrow, and specific bone cells are summarized with a comparison between different targeting ligands. Ultimately, this review will summarize recent advances in the clinical translation of bone-targeted therapies and provide a perspective on the challenges for the application of bone-targeted therapy in the clinic and future trends in this area.

Medication-Related Osteonecrosis of the Jaws (MRONJ) in Children and Young Patients-A Systematic Review

Medication-related osteonecrosis of the jaw (MRONJ) is defined by the American Association of Oral and Maxillofacial Surgeons (AAOMS) as the presence of an exposed bone area in the maxillofacial region, present for more than eight weeks in patients treated with the use of antiresorptive or antiangiogenic agents, with no history of radiation or metastatic disease. Bisphosphonates (BF) and denosumab (DS) are widely used in adults for the management of patients with cancer and osteoporosis, and recently there has been an increase in their use in child and young patients for the management of disorders such as osteogenesis imperfecta (OI), glucocorticoid-induced osteoporosis, McCune-Albright syndrome (MAS), malignant hypercalcemia, and others. There are differences between case reports in adults compared to child and young patients related to the use of antiresorptive/antiangiogenic drugs and the development of MRONJ. The aim was to analyze the presence of MRONJ in children and young patients, and the relation with oral surgery. A systematic review, following the PRISMA search matrix based on the PICO question, was conducted in PubMed, Embase, ScienceDirect, Cochrane, Google Scholar, and manual search in high-impact journals between 1960 and 2022, publications in English or Spanish, including randomized and non-randomized clinical trials, prospective and retrospective cohort studies, cases and controls studies, and series and case reports. A total of 2792 articles were identified and 29 were included; all of them published between 2007 and 2022, identifying 1192 patients, 39.68% male and 36.24% female, aged 11.56 years old on average, using these drugs mainly for OI (60.15%); 4.21 years on average was the therapy time and 10.18 drug doses administered on average; oral surgery was observed in 216 subjects, reporting 14 cases of MRONJ. We concluded that there is a low presence of MRONJ in the child and youth population treated with antiresorptive drugs. Data collection is weak, and details of therapy are not clear in some cases. Deficiencies in protocols and pharmacological characterization were observed in most of the included articles.

Characterization of the Tumor Microenvironment in Jaw Osteosarcomas, towards Prognostic Markers and New Therapeutic Targets

Background-The purpose of this study was to investigate the bone resorption, as well as the vascular and immune microenvironment, of jaw osteosarcomas (JO) and to correlate these features with patient clinical outcomes. Methods-We studied 50 JO biopsy samples by immunohistochemical analysis of tissue microarrays (TMAs). We investigated the bone remodeling markers RANK/RANKL/OPG, the endothelial glycoprotein CD146, and biomarkers of the immune environment (CD163 and CD68 of macrophages, CD4+ and CD8+ of tumor-infiltrating lymphocytes (TILs), and an immune checkpoint PD-1/PD-L1). The biomarkers were analyzed for their influence on progression (recurrence and metastasis), overall survival (OS), and disease-free survival (DFS). Results-A strong and significant correlation has been found between CD163 staining and lower OS and DFS. The level of CD4+ and CD8+ staining was low and non-significantly associated with survival outcomes. High levels of RANK and RANKL were found in the tumor samples and correlated with lower DFS. Conclusion-Our findings suggest that CD163+ TAMs represent markers of poor prognosis in JO. Targeting TAMs could represent a valuable therapeutic strategy in JO.

Microenvironment-responsive electrocution of tumor and bacteria by implants modified with degenerate semiconductor film

Implantable biomaterials are widely used in the curative resection and palliative treatment of various types of cancers. However, cancer residue around the implants usually leads to treatment failure with cancer reoccurrence. Postoperation chemotherapy and radiation therapy are widely applied to clear the residual cancer cells but induce serious side effects. It is urgent to develop advanced therapy to minimize systemic toxicity while maintaining efficient cancer-killing ability. Herein, we report a degenerate layered double hydroxide (LDH) film modified implant, which realizes microenvironment-responsive electrotherapy. The film can gradually transform into a nondegenerate state and release holes. When in contact with tumor cells or bacteria, the film quickly transforms into a nondegenerate state and releases holes at a high rate, rendering the "electrocution" of tumor cells and bacteria. However, when placed in normal tissue, the hole release rate of the film is much slower, thus, causing little harm to normal cells. Therefore, the constructed film can intelligently identify and meet the physiological requirements promptly. In addition, the transformation between degenerate and nondegenerate states of LDH films can be cycled by electrical charging, so their selective and dynamic physiological functions can be artificially adjusted according to demand.

GINS2 Promotes Osteosarcoma Tumorigenesis via STAT3/MYC Axis

GINS2 is overexpressed in several cancers, but little is known about its role in osteosarcoma (OS). A series of in vivo and in vitro experiments were conducted to explore the role of GINS2 in OS. In this study, we demonstrated that GINS2 was found to be highly expressed in OS tissues and cell lines, which was associated with poor outcomes in OS patients. GINS2 knockdown hindered the growth and induced apoptosis in OS cell lines in vitro. Furthermore, GINS2 knockdown effectively inhibited the growth of a xenograft tumor in vivo. By using an Affymetrix gene chip and intelligent pathway analysis, it was demonstrated that the GINS2 knockdown could reduce the expression of several targeted genes and reduce the activity of the MYC signaling pathway. Mechanically, LC-MS, CoIP, and rescue experiments revealed that GINS2 promoted tumor progression through the STAT3/MYC axis in the OS. Moreover, GINS2 was associated with tumor immunity and may be a potential immunotherapeutic target for OS.

Evaluation of zoledronate for the treatment of canine stage III osteosarcoma: A phase II study

BACKGROUND

Greater than 90% of dogs with appendicular osteosarcoma will develop pulmonary metastasis despite the standard of care. Available treatments have limited efficacy for stage III disease. Zoledronate, a bisphosphonate, induces apoptosis of canine osteosarcoma cells and appears to modulate the tumour microenvironment.

OBJECTIVES

This prospective, single institutional phase IIa trial investigated the use of single agent zoledronate in dogs with pulmonary metastases from osteosarcoma.

METHODS

Zoledronate was administered once monthly, and thoracic radiographs were used to assess response.

RESULTS

Eleven dogs were enrolled. Stable disease was achieved in two of eight dogs available for response assessment. The median progression-free survival was 28 days (range: 4-93 days). The median stage III-specific survival time was 92 days. Adverse events were reported in four dogs; two dogs developed grade III or higher toxicities. Notable adverse events included conjunctivitis, fever, hypocalcaemia, and hypophosphatemia.

CONCLUSIONS

Zoledronate appears to have limited efficacy as a single agent for stage III osteosarcoma and may be associated with unexpected toxicity in this population. This clinical trial was registered on the AVMA Animal Health Studies Database (AAHSD004396).

Immune checkpoint inhibitors in osteosarcoma: A hopeful and challenging future

Osteosarcoma (OS), the most common malignant tumor in the musculoskeletal system, mainly occurs in adolescents. OS results in high mortality and disability rates due to a fatal metastatic tendency and subsequent iatrogenic damage caused by surgery, radiotherapy and chemotherapy. Recently, immunotherapies have resulted in promising prognoses with reduced side effects compared with traditional therapies. Immune checkpoint inhibitors (ICIs), which are a representative immunotherapy for OS, enhance the antitumor effects of immune cells. ICIs have shown satisfactory outcomes in other kinds of malignant tumors, especially hemopoietic tumors. However, there is still a high percentage of failures or severe side effects associated with the use of ICIs to treat OS, leading to far worse outcomes. To reveal the underlying mechanisms of drug resistance and side effects, recent studies elucidated several possible reasons, including the activation of other inhibitory immune cells, low immune cell infiltration in the tumor microenvironment, different immune properties of OS subtypes, and the involvement of osteogenesis and osteolysis. According to these mechanisms, researchers have developed new methods to overcome the shortcomings of ICIs. This review summarizes the recent breakthroughs in the use of ICIs to treat OS. Although numerous issues have not been solved yet, ICIs are still the most promising treatment options to cure OS in the long run.

Heparin and Heparin-Based Drug Delivery Systems: Pleiotropic Molecular Effects at Multiple Drug Resistance of Osteosarcoma and Immune Cells

One of the main problems of modern health care is the growing number of oncological diseases both in the elderly and young population. Inadequately effective chemotherapy, which remains the main method of cancer control, is largely associated with the emergence of multidrug resistance in tumor cells. The search for new solutions to overcome the resistance of malignant cells to pharmacological agents is being actively pursued. Another serious problem is immunosuppression caused both by the tumor cells themselves and by antitumor drugs. Of great interest in this context is heparin, a biomolecule belonging to the class of glycosaminoglycans and possessing a broad spectrum of biological activity, including immunomodulatory and antitumor properties. In the context of the rapid development of the new field of “osteoimmunology,” which focuses on the collaboration of bone and immune cells, heparin and delivery systems based on it may be of intriguing importance for the oncotherapy of malignant bone tumors. Osteosarcoma is a rare but highly aggressive, chemoresistant malignant tumor that affects young adults and is characterized by constant recurrence and metastasis. This review describes the direct and immune-mediated regulatory effects of heparin and drug delivery systems based on it on the molecular mechanisms of (multiple) drug resistance in (onco) pathological conditions of bone tissue, especially osteosarcoma.

Engineering Novel 3D Models to Recreate High-Grade Osteosarcoma and its Immune and Extracellular Matrix Microenvironment

Osteosarcoma (OS) is the most common primary bone cancer, where the overall 5-year surviving rate is below 20% in resistant forms. Accelerating cures for those poor outcome patients remains a challenge. Nevertheless, several studies of agents targeting abnormal cancerous pathways have yielded disappointing results when translated into clinic because of the lack of accurate OS preclinical modeling. So, any effort to design preclinical drug testing may consider all inter-, intra-, and extra-tumoral heterogeneities throughout models mimicking extracellular and immune microenvironment. Therefore, the bioengineering of patient-derived models reproducing the OS heterogeneity, the interaction with tumor-associated macrophages (TAMs), and the modulation of oxygen concentrations additionally to recreation of bone scaffold is proposed here. Eight 2D preclinical models mimicking several OS clinical situations and their TAMs in hypoxic conditions are developed first and, subsequently, the paired 3D models faithfully preserving histological and biological characteristics are generated. It is possible to shape reproducibly M2-like macrophages cultured with all OS patient-derived cell lines in both dimensions. The final 3D models pooling all heterogeneity features are providing accurate proliferation and migration data to understand the mechanisms involved in OS and immune cells/biomatrix interactions and sustained such that engineered 3D preclinical systems will improve personalized medicine.

Individual Trajectories of Bone Mineral Density Reveal Persistent Bone Loss in Bone Sarcoma Patients: A Retrospective Study

Multiagent chemotherapy offers an undoubted therapeutic benefit to cancer patients, but is also associated with chronic complications in survivors. Osteoporosis affects the quality of life of oncologic patients, especially at the paediatric age. However, very few studies have described the extent of loss of bone mineral density (BMD) in bone sarcoma patients. We analysed a retrospective series of children and adolescents with primary malignant bone tumours (52 osteosarcoma and 31 Ewing sarcoma) and retrieved their BMD at diagnosis and follow-up as Hounsfield units (HU). We studied their individual BMD trajectories before and after chemotherapy up to 5 years, using routine chest CT scan and attenuation thresholds on T12 vertebrae ROI. At one year, bone sarcoma patients showed significant bone loss compared to diagnosis: 17.6% and 17.1% less for OS and EW, respectively. Furthermore, a bone loss of more than 49.2 HU at one-year follow-up was predictive of the persistence of a reduced bone mass over the following 4 years, especially in patients with EW. At 4 years, only 26% and 12.5% of OS and EW, respectively, had recovered or improved their BMD with respect to the onset, suggesting a risk of developing morbidities related to a low BMD in those subjects.

Prognostic impact of pulmonary nodules diagnosed at initial presentation in patients with osteosarcoma

BACKGROUND

Resection of all lung metastases in patients with osteosarcoma improves survival. The increased computed tomography (CT) scan quality allows detecting smaller nodules. We aimed to evaluate the prognostic impact of those nodules that do not meet the classical criteria for lung metastases.

METHODS

A central radiology review (CRR) on lung CT scans performed during the treatment of patients included in OS2006 trial and treated with a high-dose methotrexate-based chemotherapy from 2007 to 2013 was realized in three centers.

RESULTS

At trial enrollment, among 77 patients, six (8%) had nodules meeting the trial's criteria for metastatic disease, 46 (60%) were classified as having localized disease, and 25 (32%) as having doubtful nodules. After CRR, 218 nodules were found at diagnosis (all in patients classified as "metastatic or doubtful" and 13 patients classified as "localized") (median two nodules per patient [1-52]). The 5-year event-free survival/overall survival (EFS/OS) of patients with at least one nodule versus no nodule were similar (67.7%/79.2% vs. 81.8%/91%). After histological analysis, two of 46 (4.3%) "localized" and eight of 25 (32.0%) "doubtful" patients were re-classified as "metastatic," whereas there was no change in patients initially "metastatic." The 5-year OS of confirmed histological metastatic versus nonmetastatic patients were different (56% vs. 92%, p < .01).

CONCLUSION

Central review of lung CT scan increased the detection of nodules in osteosarcoma. Patients with small lung nodules classified as doubtful had a quite similar outcome as those with a localized disease. However, patients with confirmed metastatic nodules have a poorer prognosis, even if considered as "localized" at diagnosis.

Insight into the interplay between mitochondria-regulated cell death and energetic metabolism in osteosarcoma

Osteosarcoma (OS) is a pediatric malignant bone tumor that predominantly affects adolescent and young adults. It has high risk for relapse and over the last four decades no improvement of prognosis was achieved. It is therefore crucial to identify new drug candidates for OS treatment to combat drug resistance, limit relapse, and stop metastatic spread. Two acquired hallmarks of cancer cells, mitochondria-related regulated cell death (RCD) and metabolism are intimately connected. Both have been shown to be dysregulated in OS, making them attractive targets for novel treatment. Promising OS treatment strategies focus on promoting RCD by targeting key molecular actors in metabolic reprogramming. The exact interplay in OS, however, has not been systematically analyzed. We therefore review these aspects by synthesizing current knowledge in apoptosis, ferroptosis, necroptosis, pyroptosis, and autophagy in OS. Additionally, we outline an overview of mitochondrial function and metabolic profiles in different preclinical OS models. Finally, we discuss the mechanism of action of two novel molecule combinations currently investigated in active clinical trials: metformin and the combination of ADI-PEG20, Docetaxel and Gemcitabine.

Origin and Therapies of Osteosarcoma

Simple Summary

Osteosarcoma is the most common malignant bone tumor in children, with a 5-year survival rate ranging from 70% to 20% depending on the aggressiveness of the disease. The current treatments have not evolved over the past four decades due in part to the genetic complexity of the disease and its heterogeneity. This review will summarize the current knowledge of OS origin, diagnosis and therapies.

Abstract

Osteosarcoma (OS) is the most frequent primary bone tumor, mainly affecting children and young adults. Despite therapeutic advances, the 5-year survival rate is 70% but drastically decreases to 20–30% for poor responders to therapies or for patients with metastasis. No real evolution of the survival rates has been observed for four decades, explained by poor knowledge of the origin, difficulties related to diagnosis and the lack of targeted therapies for this pediatric tumor. This review will describe a non-exhaustive overview of osteosarcoma disease from a clinical and biological point of view, describing the origin, diagnosis and therapies.

A simple, universal and multifunctional template agent for personalized treatment of bone tumors

Bone tumors occur in bone or its accessory tissues. Benign bone tumors are easy to cure and have good prognosis, while malignant bone tumors develop rapidly and have poor and high mortality. So far, there is no satisfactory treatment method. Here, we designed a universal template vector for bone tumor therapy that simultaneously meets the needs of bone targeting, tumor killing, osteoclast suppression, and tumor imaging. The template is composed of a polydopamine (PDA) core and a multifunctional surface. PDA has excellent biosafety and photothermal performance. In this study, alendronate sodium (ALN) is grafted to enable its general bone targeting function. PDA core can carry a variety of chemotherapy drugs, and the rich ALN group can carry a variety of metal ions with an imaging function. Therefore, more personalized treatment plans can be designed for different bone tumor patients. In addition, the PDA core enables photothermal therapy and enhanced chemotherapy. Through template drug Doxorubicin (DOX) and template imaging ion Fe (Ⅱ), we systematically verified the therapeutic effect, imaging effect, and inhibition of bone dissolution of the agent on Osteosarcoma (OS), a primary malignant bone tumor, in vivo. In conclusion, our work provides a more general template carrier for the clinical treatment of bone tumors, through which personalized treatment of bone tumors can be achieved.

•

The PDA-ALN-DOX presented high bone targeting property, photothermal conversion efficiency, drug loading capacity, and multimodal imaging modalities.

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CPT is a more efficient and convenient therapy for bone tumors.

Osteosarcoma: A Surveillance, Epidemiology, and End Results program-based analysis from 1975 to 2017

BACKGROUND

Osteosarcoma is the most common primary bone malignancy. As a rare cancer, population-based studies remain small with limited information on finer demographic categories. Recent studies have reported important genetic differences based on age and ethnicity, and more detailed studies are needed to better understand potentially important osteosarcoma risk groups.

METHODS

Incidence and survival rates for 5016 patients with osteosarcoma from the Surveillance, Epidemiology, and End Results (SEER) program (1975-2017) were analyzed by age (0-9, 10-24, 25-59, and >60 years old), race/ethnicity, histologic subtype, stage, and tumor location using SEER*Stat software.

RESULTS

For cases 0 to 9 years old, incidence of primary osteosarcoma was similar between the sexes, increased significantly throughout the study period (P < .05), and the 5-year relative survival has steadily increased over time. Blacks had the highest incidence in all aged cases combined and a significant increase in incidence throughout the study period (P < .05). Overall, survival rates for all cases have remained relatively unchanged over recent decades, with worse survival observed in males, American Indian/Alaska Native cases, older patients, metastatic disease, axial tumors, and subsequent osteosarcoma cases. For cases 0 to 24 years old, the incidence of subsequent osteosarcoma increased 3-fold since the 2000s.

CONCLUSION

Important differences in osteosarcoma incidence and survival, particularly for the youngest children, ethnic minorities, and subsequent osteosarcoma, are identified. A genetic risk factor may be associated with observed ancestry-specific incidence differences and illustrates the importance of analyzing osteosarcoma by specific age groups and ethnicities to better understand their unique epidemiology and underlying biology.

LAY SUMMARY

Osteosarcoma is the most common bone cancer, but still a relatively rare disease, and previous studies have had limited information on finer demographics. Using a large database, osteosarcoma incidence and survival patterns are thoroughly evaluated and important differences, especially for the youngest children, ethnic minorities, and subsequent osteosarcoma cases, are identified.

Therapeutic Effects of Zoledronic Acid-Loaded Hyaluronic Acid/Polyethylene Glycol/Nano-Hydroxyapatite Nanoparticles on Osteosarcoma

Zoledronic acid (ZOL) has been approved as the only bisphosphonate for the prevention and treatment of metastatic bone diseases with acceptable safety and tolerability. However, systemic or direct injection of ZOL often causes severe side effects, which limits its clinical application. Here, an innovative nano-drug delivery system, ZOL-loaded hyaluronic acid/polyethylene glycol/nano-hydroxyapatite nanoparticles (HA-PEG-nHA-ZOL NPs), has been found to effectively inhibit the proliferation of three types of human osteosarcoma cell lines (143b, HOS, and MG63) at 1-10 μmol/L, while with low cell cytotoxicity on normal cells. The NPs significantly enhanced the apoptosis-related protein expression and tumor cell apoptosis rate. The NPs could also inhibit the proliferation of osteosarcoma cells by blocking the S phase of the cell cycle. In the orthotopic osteosarcoma nude mice model, local injection of the HA-PEG-nHA-ZOL NPs stimulated tumor necrosis, apoptosis, and granulocyte infiltration in the blood vessels. Altogether, the ZOL nano-delivery system possesses great potential for local treatment to prevent local tumor recurrence and can be applied in clinical osteosarcoma therapy.

The Construction and Development of a Clinical Prediction Model to Assess Lymph Node Metastases in Osteosarcoma

Background: This study aimed to construct a clinical prediction model for osteosarcoma patients to evaluate the influence factors for the occurrence of lymph node metastasis (LNM).

Methods: In our retrospective study, a total of 1,256 patients diagnosed with chondrosarcoma were enrolled from the SEER (Surveillance, Epidemiology, and End Results) database (training cohort, n = 1,144) and multicenter dataset (validation cohort, n = 112). Both the univariate and multivariable logistic regression analysis were performed to identify the potential risk factors of LNM in osteosarcoma patients. According to the results of multivariable logistic regression analysis, A nomogram were established and the predictive ability was assessed by calibration plots, receiver operating characteristics (ROCs) curve, and decision curve analysis (DCA). Moreover, Kaplan-Meier plot of overall survival (OS) was plot and a web calculator visualized the nomogram.

Results: Five independent risk factors [chemotherapy, surgery, lung metastases, lymphatic metastases (M-stage) and tumor size (T-stage)] were identified by multivariable logistic regression analysis. What's more, calibration plots displayed great power both in training and validation group. DCA presented great clinical utility. ROCs curve provided the predictive ability in the training cohort (AUC = 0.805) and the validation cohort (AUC = 0.808). Moreover, patients in LNN group had significantly better survival than that in LNP group both in training and validation group.

Conclusion: In this study, we constructed and developed a nomogram with risk factors, which performed well in predicting risk factors of LNM in osteosarcoma patients. It may give a guide for surgeons and oncologists to optimize individual treatment and make a better clinical decision.

Bone Health Issues in the Pediatric Oncology Patient

OBJECTIVE

This article reviews how childhood cancers and related treatments affect bone integrity. Interventions related to exercise, hormone replacement, vitamin D and calcium supplementation, and bisphosphonate use are addressed.

DATA SOURCES

Literature was reviewed related to childhood cancers, treatment and side effects, assessment, and management to optimize bone health.

CONCLUSIONS

Cure rates of childhood cancer have dramatically improved due to new therapeutic advances allowing children diagnosed with cancer to live longer. Unfortunately, the cost of cure can be the increased development of chronic health issues. Since many children receive their treatment, including antineoplastic agents, radiation, surgery, and corticosteroid therapy, during time of active skeletal maturation and growth, their bone health may be negatively impacted. The development of bone mass can be impaired, bone density may be decreased, fractures may occur, growth may be restricted, and there may be poor bone repair. Review of the data indicates that more research is needed to understand what is necessary for optimal bone health in the pediatric population in general, specifically for the child affected by cancer.

IMPLICATIONS FOR NURSING PRACTICE

Nurses are integral to the development of comprehensive understanding of the bone health needs of the pediatric oncology patient population and educating the patient and family about the importance of bone health. Children and young adult survivors would benefit from collaborative care between all their health care providers. Steps to improve bone health before diagnosis, on treatment, and through to survivorship remain to be addressed by future research.

Inhibiting Endothelin Receptors with Macitentan Strengthens the Bone Protective Action of RANKL Inhibition and Reduces Metastatic Dissemination in Osteosarcoma

Simple Summary

The efficacy of current osteosarcoma therapy is diminished by two adverse events, namely resistance to chemotherapy and metastatic dissemination. In recent decades, research has been devoted to reducing these adverse events. Inhibiting bone resorption has shown promising effects on metastatic dissemination and tumor growth, with, however, the formation of significant tumoral mineralized tissue. Endothelin signaling is implicated in activating the cell that forms the mineralized tissues, consequently the impact of inhibiting it alone and in combination with the inhibition of bone resorption was evaluated using osteosarcoma models. The results obtained showed that inhibiting endothelin signaling significantly reduced the formation of mineralized tumor tissue concomitantly to metastatic dissemination without affecting sensitivity to chemotherapy. This inhibition appears to be a promising new therapeutic tool in the fight against osteosarcoma.

Abstract

Current treatments for osteosarcoma, combining conventional polychemotherapy and surgery, make it possible to attain a five-year survival rate of 70% in affected individuals. The presence of chemoresistance and metastases significantly shorten the patient’s lifespan, making identification of new therapeutic tools essential. Inhibiting bone resorption has been shown to be an efficient adjuvant strategy impacting the metastatic dissemination of osteosarcoma, tumor growth, and associated bone destruction. Unfortunately, over-apposition of mineralized matrix by normal and tumoral osteoblasts was associated with this inhibition. Endothelin signaling is implicated in the functional differentiation of osteoblasts, raising the question of the potential value of inhibiting it alone, or in combination with bone resorption repression. Using mouse models of osteosarcoma, the impact of macitentan, an endothelin receptor inhibitor, was evaluated regarding tumor growth, metastatic dissemination, matrix over-apposition secondary to RANKL blockade, and safety when combined with chemotherapy. The results showed that macitentan has no impact on tumor growth or sensitivity to ifosfamide, but significantly reduces tumoral osteoid tissue formation and the metastatic capacity of the osteosarcoma. To conclude, macitentan appears to be a promising therapeutic adjuvant for osteosarcoma alone or associated with bone resorption inhibitors.

Recent and Ongoing Research into Metastatic Osteosarcoma Treatments

The survival rate for metastatic osteosarcoma has not improved for several decades, since the introduction and refinement of chemotherapy as a treatment in addition to surgery. Over two thirds of metastatic osteosarcoma patients, many of whom are children or adolescents, fail to exhibit durable responses and succumb to their disease. Concerted efforts have been made to increase survival rates through identification of candidate therapies via animal studies and early phase trials of novel treatments, but unfortunately, this work has produced negligible improvements to the survival rate for metastatic osteosarcoma patients. This review summarizes data from clinical trials of metastatic osteosarcoma therapies as well as pre-clinical studies that report efficacy of novel drugs against metastatic osteosarcoma in vivo. Considerations regarding the design of animal studies and clinical trials to improve survival outcomes for metastatic osteosarcoma patients are also discussed.

Together Intra-Tumor Hypoxia and Macrophagic Immunity Are Driven Worst Outcome in Pediatric High-Grade Osteosarcomas

Simple Summary

Radiological and immunohistochemical data were correlated with the outcome in a retrospective monocentric cohort of 30 pediatric osteosarcomas (OTS). A necrotic volume of more than 50 cm³ at diagnosis was significantly linked to a worse overall survival (OS). Regarding immunohistochemical analyses, an overexpression of hypoxic markers, such as HIF-1α and anhydrase carbonic IX (CAIX), was significantly linked to a worse OS, while pS6-RP hyperexpression was correlated with a better survival. We also featured that CD68 positive cells, representative of macrophagic M1 polarization, were mostly associated with HIF-1α and CAIX hyperexpressions and that M2-like polarization, mostly related to CD163 positivity, was correlated to mTor activation. These findings, involving clinical, radiological and biology data, allowed us to hypothesize a dual signature association ready to use routinely in future protocols.

Abstract

Background: Osteosarcomas (OTS) represent the most common primary bone cancer diagnosed in adolescents and young adults. Despite remarkable advances, there are no objective molecular or imaging markers able to predict an OTS outcome at diagnosis. Focusing on biomarkers contributing broadly to treatment resistance, we examine the interplay between the tumor-associated macrophages and intra-tumor hypoxia. Methods: Radiological and immunohistochemical (IHC) data were correlated with the outcome in a retrospective and monocentric cohort of 30 pediatric OTS. We studied hypoxic (pS6, phospho-mTor, HIF-1α and carbonic anhydrase IX (CAIX)) and macrophagic (CD68 and CD163) biomarkers. Results: The imaging analyses were based on MRI manual volumetric measures on axial post-contrast T1 weighted images, where, for each tumor, we determined the necrotic volume and its ratio to the entire tumor volume. When they were above 50 cm³ and 20%, respectively, they correlated with a worse overall survival (p = 0.0072 and p = 0.0136, respectively) and event-free survival (p = 0.0059 and p = 0.0143, respectively). IHC assessments enable a significant statistical link between HIF-1α/CAIX hyper-expressions, CD68+ cells and a worse outcome, whereas activation of mTor pathway was linked to a better survival rate and CD163+ cells. Conclusions: This study evidenced the links between hypoxia and immunity in OTS, as their poor outcome may be related to a larger necrotic volume on diagnostic MRI and, in biopsies, to a specific IHC profile.

The Emerging Role of PRMT6 in Cancer

Protein arginine methyltransferase 6 (PRMT6) is a type I PRMT that is involved in epigenetic regulation of gene expression through methylating histone or non-histone proteins, and other processes such as alternative splicing, DNA repair, cell proliferation and senescence, and cell signaling. In addition, PRMT6 also plays different roles in various cancers via influencing cell growth, migration, invasion, apoptosis, and drug resistant, which make PRMT6 an anti-tumor therapeutic target for a variety of cancers. As a result, many PRMT6 inhibitors are being utilized to explore their efficacy as potential drugs for various cancers. In this review, we summarize the current knowledge on the function and structure of PRMT6. At the same time, we highlight the role of PRMT6 in different cancers, including the differentiation of its promotive or inhibitory effects and the underlying mechanisms. Apart from the above, current research progress and the potential mechanisms of PRMT6 behind them were also summarized.

Pseudomyogenic hemangioendothelioma with bone and soft tissue involvement with favorable response to pamidronate: a case report and systematic review of the literature

Pseudomyogenic hemangioendothelioma (PMH) can be a challenge for diagnosis and might be confused with other tumors, such as epithelioid sarcoma. Here we present a case and a systematic review of the literature to identify and discuss PMH treatment in primary bone involvement. A 25-year-old woman was referred for bone pain (10/10) in the left lower limb. Magnetic resonance imaging (MRI) showed multiple bone lesions (left femur, tibia, patella, ankle, and foot) with well-defined borders without signs of local aggressiveness. Positron Emission Tomography-Computed Tomography (PET-CT) showed multiple metabolic musculoskeletal lesions in the left lower limb. A CT scan-guided biopsy was performed. Histological and immunohistochemical findings confirmed the diagnosis of PMH. After treatment with intravenous pamidronate (90 mg/monthly), the patient had clinical improvement, mild pain 2/10 without the use of non-steroidal anti-inflammatory drugs or opiates. Follow-up was assessed by MRI and PET-CT. PET-CT showed metabolic resolution of most of the bone and muscular lesions and a significant improvement of the femoral lesion. MRI showed that the lesions in the left femur, tibia, and foot had a marked decrease in size without intravenous post-contrast enhancement and smaller lesions had disappeared. After a 3-year follow-up, PET-CT showed no metabolically active images. Literature review identified 31 records including 58 clinical cases of PMH with primary bone involvement and treatment description for qualitative analysis. Most lesions (69%) were treated by local excision or curettage. In addition, amputations were performed in a significant percentage of cases (20.7%). In the last years, mTOR inhibitors (n = 7) and anti-resorptive treatments (n = 4) were considered as alternative treatment options, especially in multifocal lesions.