Advanced chondrosarcomas: role of chemotherapy and survival

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

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

Development of Injectable Thermosensitive Nanocomposite Hydrogel for Ratiometric Drug Delivery to Treat Drug Resistant Chondrosarcoma In Vivo

Chondrosarcoma(CS), a prevalent primary malignant bone tumor, frequently exhibits chemotherapy resistance attributed to upregulated anti-apoptosis pathways such as the Bcl-2 family. In this manuscript, a new strategy is presented to augment chemosensitivity and mitigate systemic toxicity by harnessing a nano-enabled drug delivery hydrogel platform. The platform utilizes "PLGA-PEG-PLGA", an amphiphilic triblock copolymer combining hydrophilic polyethylene glycol (PEG) and hydrophobic polylactide glycolide (PLGA) blocks, renowned for its properties conducive to crafting a biodegradable, temperature-sensitive hydrogel. This platform is tailored to encapsulate a ratiometrically designed dual-loaded liposomes containing a first-line chemo option for CS, Doxorubicin (Dox), plus a calculated amount of small molecule inhibitor for anti-apoptotic Bcl-2 pathway, ABT-737. In vitro and in vivo evaluations demonstrate successful Bcl-2 suppression, resulting in the restoration of Dox sensitivity, evident through impeded tumor growth and amplified necrosis rates at the tumor site. This delivery system showcases remarkable thermal responsiveness, injectability, and biodegradability, all finely aligned with the clinical demands of CS treatment. Collectively, this study introduces a transformative avenue for tackling drug resistance in CS chemotherapy, offering significant clinical potential.

A Systematic Review of Adjuvant Chemotherapy in Localized Dedifferentiated Chondrosarcoma

Dedifferentiated chondrosarcoma (DDCS) is a high-grade subtype of chondrosarcoma with the bimorphic histological appearance of a conventional chondrosarcoma component with abrupt transition to a high-grade, non-cartilaginous sarcoma. DDCS can be radiographically divided into central and peripheral types. Wide resection is currently the main therapeutic option for localized DDCS. Moreover, the effectiveness of adjuvant chemotherapy remains controversial. Therefore, we performed a systematic review of available evidence to evaluate the effect of adjuvant chemotherapy on localized DDCS. The purpose was to compare the 5-year survival rate among patients treated with surgery plus adjuvant chemotherapy or surgery alone for localized DDCS. The search was conducted in PubMed, Embase, and Cochrane Central Register of Controlled Trials (CENTRAL) databases. Of the 217 studies shortlisted, 11 retrospective non-randomized studies (comprising 556 patients with localized DDCS) were selected. The 5-year survival rates were similar between the two treatment groups (28.2% (51/181) vs. 24.0% (90/375), respectively). The overall pooled odds ratio was 1.25 (95% confidence interval: 0.80-1.94; p = 0.324), and heterogeneity I2 was 2%. However, when limited to peripheral DDCS, adjuvant chemotherapy was associated with prolonged survival (p = 0.03). Due to the paucity of included studies and the absence of prospective comparative studies, no conclusions can be drawn regarding the effectiveness or ineffectiveness of adjuvant chemotherapy for localized DDCS.

Intratumoral and peritumoral CT radiomics in predicting prognosis in patients with chondrosarcoma: a multicenter study

OBJECTIVE

To evaluate the efficacy of the CT-based intratumoral, peritumoral, and combined radiomics signatures in predicting progression-free survival (PFS) of patients with chondrosarcoma (CS).

METHODS

In this study, patients diagnosed with CS between January 2009 and January 2022 were retrospectively screened, and 214 patients with CS from two centers were respectively enrolled into the training cohorts (institution 1, n = 113) and test cohorts (institution 2, n = 101). The intratumoral and peritumoral radiomics features were extracted from CT images. The intratumoral, peritumoral, and combined radiomics signatures were constructed respectively, and their radiomics scores (Rad-score) were calculated. The performance of intratumoral, peritumoral, and combined radiomics signatures in PFS prediction in patients with CS was evaluated by C-index, time-dependent area under the receiver operating characteristics curve (time-AUC), and time-dependent C-index (time C-index).

RESULTS

Eleven, 7, and 16 features were used to construct the intratumoral, peritumoral, and combined radiomics signatures, respectively. The combined radiomics signature showed the best prediction ability in the training cohort (C-index, 0.835; 95%; confidence interval [CI], 0.764-0.905) and the test cohort (C-index, 0.800; 95% CI, 0.681-0.920). Time-AUC and time C-index showed that the combined signature outperformed the intratumoral and peritumoral radiomics signatures in the prediction of PFS.

CONCLUSION

The CT-based combined signature incorporating intratumoral and peritumoral radiomics features can predict PFS in patients with CS, which might assist clinicians in selecting individualized surveillance and treatment plans for CS patients.

CRITICAL RELEVANCE STATEMENT

Develop and validate CT-based intratumoral, peritumoral, and combined radiomics signatures to evaluate the efficacy in predicting prognosis of patients with CS.

KEY POINTS

• Reliable prognostic models for preoperative chondrosarcoma are lacking. • Combined radiomics signature incorporating intratumoral and peritumoral features can predict progression-free survival in patients with chondrosarcoma. • Combined radiomics signature may facilitate individualized stratification and management of patients with chondrosarcoma.

Decoupling NAD+ metabolic dependency in chondrosarcoma by targeting the SIRT1-HIF-2α axis

Chondrosarcomas represent the second most common primary bone malignancy. Despite the vulnerability of chondrosarcoma cells to nicotinamide adenine dinucleotide (NAD+) depletion, targeting the NAD+ synthesis pathway remains challenging due to broad implications in biological processes. Here, we establish SIRT1 as a central mediator reinforcing the dependency of chondrosarcoma cells on NAD+ metabolism via HIF-2α-mediated transcriptional reprogramming. SIRT1 knockdown abolishes aggressive phenotypes of chondrosarcomas in orthotopically transplanted tumors in mice. Chondrosarcoma cells thrive under glucose starvation by accumulating NAD+ and subsequently activating the SIRT1-HIF-2α axis. Decoupling this link via SIRT1 inhibition unleashes apoptosis and suppresses tumor progression in conjunction with chemotherapy. Unsupervised clustering analysis identifies a high-risk chondrosarcoma patient subgroup characterized by the upregulation of NAD+ biosynthesis genes. Finally, SIRT1 inhibition abolishes HIF-2α transcriptional activity and sensitizes chondrosarcoma cells to doxorubicin-induced cytotoxicity, irrespective of underlying pathways to accumulate intracellular NAD+. We provide system-level guidelines to develop therapeutic strategies for chondrosarcomas.

Grade 2, 3 and Dedifferentiated Chondrosarcomas: A Comparative Study of Isocitrate Dehydrogenase-Mutant and Wild-Type Tumors with Implications for Prognosis and Therapy

BACKGROUND

Grade 2 and 3 and dedifferentiated chondrosarcomas (CS) are frequently associated with isocitrate dehydrogenase (IDH) mutations and often exhibit a poor clinical outcome. Treatment is limited mainly to surgery. Defining IDH status (wild type (WT) and mutant) and the associated transcriptome may prove useful in determining other therapeutic options in these neoplasms.

METHODS

Formalin-fixed paraffin-embedded material from 69 primary and recurrent grade 2, 3 and dedifferentiated CS was obtained. DNA sequencing for IDH1 and IDH2 mutations (n = 47) and RNA sequencing via Nextseq 2000 (n = 14) were performed. Differentially expressed genes (DEGs) were identified and used to predict aberrant biological pathways with Ingenuity Pathway Analysis (IPA) software (Qiagen). Gene Set Enrichment Analyses (GSEA) using subsets C3, C5 and C7 were performed. Differentially expressed genes were validated by immunohistochemistry. Outcome analysis was performed using the Wilcoxon test.

RESULTS

A set of 69 CS (28 females, 41 males), average age 65, distributed among femur, pelvis, humerus, and chest wall were identified from available clinical material. After further selection based on available IDH status, we evaluated 15 IDH WT and 32 IDH mutant tumors as part of this dataset. Out of 15 IDH WT tumors, 7 involved the chest wall/scapula, while 1 of 32 mutants arose in the scapula. There were far more genes overexpressed in IDH WT tumors compared to IDH mutant tumors. Furthermore, IDH WT and IDH mutant tumors were transcriptomically distinct in the IPA and GSEA, with IDH mutant tumors showing increased activity in methylation pathways and endochondral ossification, while IDH WT tumors showed more activity in normal matrix development pathways. Validation immunohistochemistry demonstrated expression of WT1 and AR in IDH WT tumors, but not in IDH mutants. SATB2 was expressed in IDH mutant tumors and not in WT tumors. Outcome analysis revealed differences in overall survival between mutant and WT tumors (p = 0.04), dedifferentiated mutant and higher-grade (2, 3) mutant tumors (p = 0.03), and dedifferentiated mutant and higher-grade (2, 3) WT tumors (p = 0.03). The longest survival times were observed in patients with higher-grade WT tumors, while patients with dedifferentiated mutant tumors showed the lowest survival. Generally, patients with IDH WT tumors displayed longer survival in both the higher-grade and dedifferentiated groups.

CONCLUSIONS

Grade 2, 3 and dedifferentiated chondrosarcomas are further characterized by IDH status, which in turn informs transcriptomic phenotype and overall survival. The transcriptome is distinct depending on IDH status, and implies different treatment targets.

Intraosseous conventional central chondrosarcoma does not metastasise irrespective of grade in pelvis, scapula and in long bone locations

Background

Histological grade has been regarded as the most important prognostic factor in conventional central chondrosarcoma. To evaluate whether the presence of an extraosseous tumour component is associated with a decreased metastasis-free survival or disease-specific survival and alternatively to develop a simple prognostic and clinical decision-making tool.

Material and methods

We searched two prospectively maintained international sarcoma centre databases for primary non metastatic central conventional chondrosarcomas of all grades in pelvis, scapula or long bone location, undergoing curative treatment, diagnosed between 2000 and 2020. Pre-treatment MRI scans were reviewed for the presence of an extraosseous mass. The metastasis-free survival (MFS) and disease-specific survival (DSS) were estimated by the Kaplan-Meier method from surgery to event, death or last follow-up.

Results

336 patients were identified between 2000 and 2020, undergoing surgical treatment for conventional central chondrosarcoma. 111 patients (33 %) had grade 1 tumours, 149 patients (44 %) had grade 2, and 76 patient (23 %) had grade 3 chondrosarcomas determined as the highest grade in the final resected specimen. An extraosseous soft tissue component was more frequent in higher grade tumours (p < 0.001) and present in 200 cases (60 %). None of the patients with an intraosseous tumour developed metastases or died of the disease. For patients with extraosseous tumour component, MFS was 92 % (95 % CI, 96-100) at 2-years and 74 % (95 % CI, 67-81) at 10-years and DSS was 91 % (95 % CI, 87-95) at 2-years and 75 % (95 % CI, 68-82) at 10-years. The MFS and DSS was significantly different (p < 0.001) for those patients with or without an extraosseous tumour component, irrespective of grade or anatomical location.

Discussion

The results of this study has shown that the metastatic potential of intraosseous conventional central chondrosarcoma is negligible. The presence of an extraosseous soft tissue component may be used for prognostication and to guide treatment pathways for patients with central cartilage tumours.

IDH-negative chondrosarcoma with metachronous dedifferentiation only in the metastatic site-A diagnostic pitfall

Dedifferentiated chondrosarcoma is a subtype of chondrosarcoma with a biphasic histological appearance of a chondrosarcoma component transitioning to a high-grade, noncartilaginous sarcoma. It is particularly difficult to confirm the diagnosis when a sarcoma lacking cartilaginous component occurs at a distant location from the primary lesion. The patient was a 72-year-old woman with multiple lesions in the pelvis, lungs, and liver, 18 months after resection of grade 2 central chondrosarcoma of the sternum. Imaging showed no cartilage component in any location. Although a needle biopsy from the pelvic region confirmed the diagnosis as high-grade sarcoma without a cartilage component, it was difficult to distinguish between a new primary sarcoma and metachronous metastatic lesions from patient's known prior dedifferentiated chondrosarcoma. We therefore performed a comparative molecular analysis by whole-exome sequencing of the biopsy sample and the resected sternal central chondrosarcoma. Both lesions had no IDH1/2 mutations but shared 19 somatic mutations and wide-range chromosomal losses, indicating similar origin. This case illustrates the challenge is coupling a diagnosis of metastatic dedifferentiated chondrosarcoma when no chondroid component is evident. Our study also highlights the benefit of genomic analysis in this differential diagnosis, especially in the context of dedifferentiated chondrosarcoma lacking IDH1/2 mutations.

Construction of novel predictive tools for post-surgical cancer-specific survival probability in patients with primary chondrosarcoma and external validation in Chinese cohorts: a large population-based retrospective study

BACKGROUND

Surgery is the predominant treatment modality for chondrosarcoma. This study aims to construct a novel clinic predictive tool that accurately predicts the 3-, 5-, and 8-year probability of cancer-specific survival (CSS) for primary chondrosarcoma patients who have undergone surgical treatment.

METHODS

The Surveillance, Epidemiology, and End Results (SEER) database was used to identify 982 primary chondrosarcoma patients after surgery, who were randomly divided into two sets: training set (60%) and internal validation set (40%). Cox proportional regression analyses were used to screen post-surgical independent prognostic variables in primary chondrosarcoma patients. These identified variables were used to construct a nomogram to predict the probability of post-surgical CSS of primary chondrosarcoma patients. The k-fold cross-validation method (k = 10), Harrell's concordance index (C-index), receiver operating characteristic curve (ROC) and area under curve (AUC) were used to assess the predictive accuracy of the nomogram. Calibration curve and decision curve analysis (DCA) were used to validate the clinical application of the nomogram.

RESULTS

Age, tumor size, disease stage and histological type were finally identified post-surgical independent prognostic variables. Based the above variables, a nomogram was constructed to predict the 3-, 5- and 8-year probability of post-surgical CSS in primary chondrosarcoma patients. The results of the C-index showed excellent predictive performance of the nomogram (training set: 0.837, 95% CI: 0.766-0.908; internal validation set: 0.835, 95% CI: 0.733-0.937; external validation set: 0.869, 95% CI: 0.740-0.998). The AUCs of ROC were all greater than 0.830 which again indicated that the nomogram had excellent predictive performance. The results of calibration curve and DCA indicated that the clinical applicability of this nomogram was outstanding. Finally, the risk classification system and online access version of the nomogram was developed.

CONCLUSION

We constructed the first nomogram to accurately predict the 3-, 5- and 8-year probability of post-surgical CSS in primary chondrosarcoma patients. This nomogram would assist surgeons to provide individualized post-surgical survival predictions and clinical strategies for primary chondrosarcoma patients.

High dose, dual-release polymeric films for extended surgical bed paclitaxel delivery

While surgery represents a major therapy for most solid organ cancers, local recurrence is clinically problematic for cancers such as sarcoma for which adjuvant radiotherapy and systemic chemotherapy provide minimal local control or survival benefit and are dose-limited due to off-target side effects. We describe an implantable, biodegradable poly(1,2-glycerol carbonate) and poly(caprolactone) film with entrapped and covalently-bound paclitaxel enabling safe, controlled, and extended local delivery of paclitaxel achieving concentrations 10,000× tissue levels compared to systemic administration. Films containing entrapped and covalently-bound paclitaxel implanted in the tumor bed, immediately after resection of human cell line-derived chondrosarcoma and patient-derived xenograft liposarcoma and leiomyosarcoma in mice, improve median 90- or 200-day recurrence-free and overall survival compared to control mice. Furthermore, mice in the experimental film arm show no film-related morbidity. Continuous, extended, high-dose paclitaxel delivery via this unique polymer platform safely improves outcomes in three different sarcoma models and provides a rationale for future incorporation into human trials.

Dedifferentiated Chondrosarcoma: Diagnostic Controversies and Emerging Therapeutic Targets

PURPOSE OF REVIEW

The pathogenesis of dedifferentiated chondrosarcoma is controversial, and no genetic abnormality has consistently been identified in the disease. Focusing on the diagnostic challenges encountered in dedifferentiated chondrosarcoma, the following review aims at summarizing the tumor's active neoplastic pathways while highlighting therapeutic modalities that could potentially be explored to enhance patient survivorship.

RECENT FINDINGS

Owing to the challenging examination of small needle biopsy sampling as well as the disease's overlapping morphological and immunohistochemical features with other bone and soft-tissue sarcomas, the diagnosis of dedifferentiated chondrosarcoma can be problematic. While combined doxorubicin- and cisplatin-based regimens remain the first-line systemic chemotherapy in the disease, ~50% of tumors carry EXT1/2 or IDH1/2 mutations, advancing EXT or IDH inhibitors as potential alternative therapies, respectively. Despite systemic chemotherapy, dedifferentiated chondrosarcoma remains an aggressive tumor with dismal prognosis and limited survival. A multidisciplinary collaboration across multiple cancer centers is warranted to yield an accurate diagnosis, understand the disease's underlying pathogenesis, develop adequate treatment, and improve patient survivorship.

IDH mutations in G2-3 conventional central bone chondrosarcoma: a mono institutional experience

BACKGROUND

Heterozygous isocitrate dehydrogenase (IDH) mutations occur in about half of conventional central bone chondrosarcomas (CCBC). Aim of this study was to assess the frequency and prognostic impact of IDH mutations in high grade CCBC patients.

METHODS

64 patients with G2 and G3 CCBC were included. DNA extraction, PCR amplification of IDH1/2 exon 4s, and sequencing analysis with Sanger were performed.

RESULTS

IDH mutations were detected in 24/54 patients (44%): IDH1 in 18, IDH2 in 4, and both IDH1/2 in 2 patients. The frequency of mutations was 37% in G2 vs. 69% in G3 (p = 0.039), and 100% in three Ollier disease associated chondrosarcoma. 5-year overall survival (OS) at 124 months (range 1-166) was 51%, with no significant difference based on the IDH mutational status: 61% in IDHmut vs. 44% in IDH wild type (IDHwt). The 5-year relapse free survival (RFS) was 33% (95% CI:10-57) for IDHmut vs. 57% (95%CI: 30-77) for IDHwt. Progression free survival (PFS) was 25% (95%CI:1-65) IDHmut vs. 16% (95%CI: 0.7-52) IDHwt. 55% (5/9) of IDHmut G2 became higher grade at the recurrence, as compared with 25% (3/12) of G2 IDHwt.

CONCLUSIONS

This study shows a higher frequency of IDH mutations in G3 CCBC as compared with G2. No significant differences in OS, RFS, and PFS by mutational status were detected. After relapse, a higher rate of G3 for IDH mutated CCBC was observed.

Dedifferentiated Chondrosarcoma from Molecular Pathology to Current Treatment and Clinical Trials

Dedifferentiated chondrosarcoma (DDCS) is a rare subtype of chondrosarcoma, a primary cartilaginous malignant neoplasm. It accounts for up to 1-2% of all chondrosarcomas and is generally associated with one of the poorest prognoses among all chondrosarcomas with the highest risk of metastasis. The 5-year survival rates range from 7% to 24%. DDCS may develop at any age, but the average presentation age is over 50. The most common locations are the femur, pelvis humerus, scapula, rib, and tibia. The standard treatment for localised disease is surgical resection. Most patients are diagnosed in unresectable and advanced stages, and chemotherapy for localised and metastatic dedifferentiated DDCS follows protocols used for osteosarcoma.

A Retrospective Multi-Institutional Cohort Analysis of Clinical Characteristics and Outcomes in Dedifferentiated Chondrosarcoma

BACKGROUND

Dedifferentiated chondrosarcoma (DDCS) is a rare subset of chondrosarcoma. It is an aggressive neoplasm characterized by a high rate of recurrent and metastatic disease with overall poor outcomes. Systemic therapy is often used to treat DDCS; however, the optimal regimen and timing are not well defined, with current guidelines recommending following osteosarcoma protocols.

METHODS

We conducted a multi-institutional retrospective analysis of clinical characteristics and outcomes of patients with DDCS. Between 1 January 2004 and 1 January 2022, the databases from five academic sarcoma centers were reviewed. Patient and tumor factors, including age, sex, tumor size, site, location, the treatments rendered, and survival outcomes, were collected.

RESULTS

Seventy-four patients were identified and included in the analysis. Most patients presented with localized disease. Surgical resection was the mainstay of therapy. Chemotherapy was used predominantly in the metastatic setting. Partial responses were low (n = 4; 9%) and occurred upon treatment with doxorubicin with cisplatin or ifosfamide and single-agent pembrolizumab. For all other regimens, stable disease was the best response. Prolonged stable disease occurred with the use of pazopanib and immune checkpoint inhibitors.

CONCLUSIONS

DDCS has poor outcomes and conventional chemotherapy has limited benefit. Future studies should focus on defining the possible role of molecularly targeted therapies and immunotherapy in the treatment of DDCS.

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.

Intracranial Metastasis of Extracranial Chondrosarcoma: Systematic Review With Illustrative Case

BACKGROUND

Cerebral chondrosarcoma metastases are rare and aggressive neoplasms. The rarity of presentation has precluded rigorous analysis of diagnosis, risk factors, treatment, and survival. We analyzed every reported case through exhaustive literature review. We further present the first case with Maffucci syndrome.

METHODS

Three databases, PubMed, Embase, and Google Scholar, and crossed references were queried for cerebral chondrosarcoma metastases. Extracted variables included demographics, risk factors, tumor characteristics, interventions, and outcomes. Univariate and multivariate analyses were performed.

RESULTS

Fifty-six patients were included from 1,489 literature results. The average age at brain metastasis was 46.6±17.6 years and occurred at a median of 24±2.8 months from primary diagnosis. Primary tumor histology (dedifferentiated 5.0±1.5 months, mesenchymal 24±3.0 months, conventional 41±7.4 months, p<0.05) and grade (low grade 54±16.7 months vs. high-grade 10±6.4 months, p<0.001) correlated with time interval until brain metastasis. A multiple enchondromatosis syndrome occurred in 13.2% of cases. At time of brain metastases diagnosis, extracranial metastases were identified in 76.2% of cases. Median survival after the development of brain metastasis was 2.0±0.78 months with a 1-year survival of 10.0%. On regression analysis, surgery reduced brain metastasis mortality risk and radiation trended towards reduced mortality risk (surgery: hazard ratio [HR] 0.22, 95% confidence interval [CI] 0.064-0.763, p=0.017; radiation: HR 0.31, 95% CI 0.091-1.072, p=0.064).

CONCLUSION

We present a systematic review of cerebral chondrosarcoma metastases. Primary tumor histology and grade correlate with time until cerebral metastasis. Following cerebral metastasis, these tumors have poor prognosis and modestly benefit from surgery.

Chondrosarcoma: A Clinical Review

Chondrosarcomas are a diverse group of malignant cartilaginous matrix-producing neoplasms. Conventional chondrosarcomas are a continuum of disease based on the biologic activity of the tumor. The tumors range from the relatively biologically benign low-grade tumors or intermediate atypical cartilaginous tumors (ACTs), to malignant, aggressive high-grade tumors. The clinical presentation, radiographic and pathologic findings, treatments and outcomes vary significantly based on the histologic grade of the tumor. Chondrosarcomas present a diagnostic dilemma, particularly in the differentiation between high- and intermediate-grade tumors and that of low-grade tumors from benign enchondromas. A multidisciplinary team at a tertiary sarcoma centre allows for optimal care of these patients.

A retrospective case-control study for the comparison of 5-year survival rates: the role of adjuvant and neoadjuvant chemotherapy in craniofacial bone sarcoma in adults

Background

The impact of adjuvant or neoadjuvant chemotherapy in the treatment of craniofacial bone sarcomas has not been clarified. This study aimed to assess whether survival outcomes differed between patients who underwent adjuvant or neoadjuvant chemotherapy.

Methods

A retrospective search for adult patients diagnosed with malignant neoplasms of the craniofacial bones (International Classification of Diseases 10 codes C41.0-C41.1), within the past 20 years from the access date 28 April 2022, was conducted using the TriNetX network (TriNetX, Cambridge, MA, USA). Cohort I included patients who underwent adjuvant chemotherapy and cohort II included patients with neoadjuvant chemotherapy. A refined search for individuals that received common chemotherapeutic agents, such as methotrexate, doxorubicin, cisplatin, and/or ifosfamide, was conducted and patients were assigned to cohort A (adjuvant chemotherapy) and cohort B (neoadjuvant chemotherapy). Following matching for age and sex, Kaplan-Meier analysis was performed, and risk ratio, odds ratio (OR), and hazard ratio were calculated.

Results

Patients were assigned to two cohorts, with 181 patients each after matching. In cohorts I and II, 55 and 41 patients died, respectively. No significant differences were found between the two cohorts regarding the 5-year survival probability (I: 59.87% versus II: 68.45%; p = 0.076; log-rank test), or the risk of dying (I: 0.304 versus II: 0.227; risk difference: 0.077; p = 0.096). The risk analysis before matching for age and sex showed a significant survival benefit in cohort II (OR: 1.586; p = 0.0295; risk difference: 0.093). After a refined query to identify patients treated with methotrexate, doxorubicin, cisplatin, and/or ifosfamide, the two cohorts included 47 patients, respectively. In cohort A (adjuvant chemotherapy), 19 patients died, whereas 12 patients died in cohort B (neoadjuvant chemotherapy) within 5 years after diagnosis. Further analysis indicated a greater survival in cohort B, but the survival probability between the cohorts did not differ significantly (A: 43.55% versus B: 54.49%; p = 0.171).

Conclusion

The use of neoadjuvant chemotherapy may improve survival rates in patients with surgically treated craniofacial bone sarcomas. Due to the retrospective nature of this study, randomized controlled studies are required to derive treatment recommendations.

Biology and Management of High-Grade Chondrosarcoma: An Update on Targets and Treatment Options

This review provides an overview of histopathology, clinical presentation, molecular pathways, and potential new systemic treatments of high-grade chondrosarcomas (CS), including grade 2−3 conventional, dedifferentiated, and mesenchymal CS. The diagnosis of CS combines radiological and histological data in conjunction with patient clinical presentations. Conventional CS is the most frequent subtype of CS (85%) and represents about 25% of primary bone tumors in adults; they can be categorized according to their bone location into central, peripheral, and periosteal chondrosarcomas. Central and peripheral CS differ at the molecular level with either IDH1/2 mutations or EXT1/2 mutations, respectively. CDKN2A/B deletions are also frequent in conventional CS, as well as COL2A1 mutations. Dedifferentiated CS develops when low-grade conventional CS transforms into a high-grade sarcoma and most frequently exhibits features of osteosarcoma, fibrosarcoma, or undifferentiated pleomorphic sarcoma. Their molecular characteristics are similar to conventional CS. Mesenchymal CS is a totally different pathological entity exhibiting recurrent translocations. Their clinical presentation and management are different too. The standard treatment of CSs is wide en-bloc resection. CS are relatively radiotherapy resistant; therefore, doses >60 Gy are needed in an attempt to achieve local control in unresectable tumors. Chemotherapy is possibly effective in mesenchymal chondrosarcoma and is of uncertain value in dedifferentiated chondrosarcoma. Due to resistance to standard anticancer agents, the prognosis is poor in patients with metastatic or unresectable chondrosarcomas. Recently, the refined characterization of the molecular profile, as well as the development of new treatments, allow new therapeutic options for these rare tumors. The efficiency of IDH1 inhibitors in other malignancies suggests that these inhibitors will be part of IDH1/2 mutated conventional CS management soon. Other treatment approaches, such as PIK3-AKT-mTOR inhibitors, cell cycle inhibitors, and epigenetic or immune modulators based on improving our understanding of CS molecular biology, are emerging.

Malignant Brain and Spinal Tumors Originating from Bone or Cartilage

Malignant bone tumors affecting the brain and spine are a rare and exceedingly difficult-to-treat group of diseases. Most commonly consisting of chordoma and chondrosarcoma, these tumors also include giant-cell tumors and osteosarcomas. This chapter will cover the background, epidemiology, genetics, molecular biology, histopathology, radiographic features, clinical manifestations, therapeutic approaches, and clinical management of each entity.

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

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

Outcomes and Complications of Pelvic Chondrosarcomas Treated Using Navigation Guidance and Multidisciplinary Approach: Is the Tumor Volume a Prognostic Factor?

(1) Background: Pelvic Chondrosarcomas (CS) have a poor prognosis. The grade is the most important survival predictor; other factors are periacetabular location and Dedifferentiated CS subtype. The aim of the study is to investigate a series of CS of the pelvis, to analyze the prognostic factors that affect outcomes and to demonstrate how the use of intraoperative navigation can reduce the complications without worse outcomes. (2) Methods: Retrospective study on 35 patients (21 M, 14 F), median age at surgery 54 years (IQR 41−65), with pelvic CS, treated with hemipelvectomy under navigation guidance. (3) Results: 30 high-grade CS and 5 low-grade CS; mean follow-up 51.4 months. There was a positive linear correlation between the tumor volume and the presence of local recurrence at follow-up. The mean survival time of patients with larger chondrosarcoma volume was lower, but not significantly so. Lower MSTS score was associated with significantly lower survival time (p < 0.001). (4) Conclusion: in this series overall survival, LR and distant metastasis were comparable with recent literature, while complication rate was lower compared to similar series without the use of navigation. There was a correlation between tumor volume and local recurrence rate but not with the presence of metastasis at follow up.

Prognostic Factors for Survival in Patients With High-grade Chondrosarcoma

BACKGROUND/AIM

Chondrosarcoma (CS) is a rare primary malignant bone tumor, which is the second most common tumor after osteosarcoma. Since chemotherapy and radiotherapy have poor efficacy for CS, amputation or surgical wide resection is the main strategy for localized high-grade CS, making CS therapy difficult. As studies on high-grade CS are limited owing to its rare nature, there are many unknown prognostic factors for survival.

PATIENTS AND METHODS

This retrospective cohort study included 44 patients with high-grade CS who underwent surgery at a single institution. Overall survival (OS), distant failure-free survival (DFFS), and local failure-free survival (LFFS) were evaluated using the Kaplan-Meier method. Furthermore, we evaluated prognostic factors for survival in patients with high-grade CS using univariate and multivariate analyses.

RESULTS

The 5-year OS, LFFS, and DFFS rates of high-grade CS were 75.9%, 90.8%, and 66.5%, respectively. Univariate analysis revealed that tumor size, tumor grade, and surgical margin were significant prognostic factors for OS and DFFS, and distant metastasis was significantly associated with OS. Furthermore, the multivariate analysis indicated that the presence of local recurrence and distant metastasis was significantly associated with OS.

CONCLUSION

Local recurrence and distant metastasis were significant prognostic factors for high-grade CS.

The Effects and Mechanisms of Sennoside A on Inducing Cytotoxicity, Apoptosis, and Inhibiting Metastasis in Human Chondrosarcoma Cells

Currently, developing therapeutic strategies for chondrosarcoma (CS) remains important. Sennoside A (SA), a dianthrone glycoside from Senna and Rhubarb, is widely used as an irritant laxative, weight-loss agent, or dietary supplement, which possesses various bioactive properties such as laxative, antiobesity, and hypoglycemic activities. For the first time, our results suggested that cell proliferation and metastasis were inhibited by SA in CS SW1353 cells. SA induced cell growth arrest by inhibiting cell proliferation. The changes of N-cadherin and E-cadherin levels, the markers associated with epithelial mesenchymal transition (EMT), suggested the EMT-related mechanism of SA in inhibiting cell metastasis. Besides, SA significantly stimulated apoptosis in CS SW1353 cells, leading to cell death. The increase of Bax/Bcl2 ratio confirmed that the internal mitochondrial pathway of apoptosis was regulated by SA. In addition, the prediction of network pharmacology analysis suggested that the possible pathways of SA treatment for CS included the Wnt signaling pathway. Notably, the protein levels of the components in the Wnt pathway, such as Wnt3a, β-catenin, and c-Myc, were downregulated by SA in CS SW1353 cells. To sum up, these results demonstrated that the suppression of the growth, metastasis and the stimulation of cytotoxicity, and apoptosis mediated by SA in CS SW1353 cells were possibly caused by the inhibition of the Wnt/β-catenin pathway, indicating an underlying therapeutic prospect of SA for chondrosarcoma.

Chondroitin sulfate proteoglycan 4 expression in chondrosarcoma: A potential target for antibody-based immunotherapy

Chondrosarcoma is a common primary bone malignancy whose phenotype increases with its histologic grade. They are relatively resistant to chemotherapy and radiation therapy limiting curative options for disseminated disease. Chondroitin sulfate proteoglycan 4 (CSPG4) is a cell surface proteoglycan that is highly expressed across various human cancers, including chondrosarcoma, and has restricted distribution in healthy tissues, making it an attractive target for the antibody-based therapy. CSPG4 specific chimeric antigen receptor (CAR) T cell therapies have been shown to be effective in treating other cancers such as melanoma and triple negative breast cancer. The goal of this study was to assess the prevalence of CSPG4 in human chondrosarcoma and to assess the efficacy of CSPG4 specific CAR T cells in lysing chondrosarcoma cells in vitro. Using immunohistochemistry (IHC), we stained a tissue microarray containing primary conventional and dedifferentiated chondrosarcoma from 76 patients with CSPG4 specific monoclonal antibodies (mAbs). In addition, we incubated 2 chondrosarcoma cell lines with CSPG4-targeting CAR T cells and subsequently evaluated cell survival. Our results showed medium to high expression of CSPG4 in 29 of 41 (71%) conventional chondrosarcoma tumors and in 3 of 20 (15%) dedifferentiated chondrosarcoma tumors. CSPG4 expression showed a positive association with time to metastasis and survival in both subtypes. CSPG4 CAR T treated cell lines showed a lysis of respectively >80% and 70% demonstrating CSPG4-targeted CAR T cells effective in killing CSPG4-positive chondrosarcoma tumors.

Dynamic Predictive Models With Visualized Machine Learning for Assessing Chondrosarcoma Overall Survival

Chondrosarcoma is a malignant bone tumor with a low incidence rate. Accurate risk evaluation is crucial for chondrosarcoma treatment. Due to the limited reliability of existing predictive models, we intended to develop a credible predictor for clinical chondrosarcoma based on the Surveillance, Epidemiology, and End Results data and four Chinese medical institutes. Three algorithms (Best Subset Regression, Univariate and Cox regression, and Least Absolute Shrinkage and Selector Operator) were used for the joint training. A nomogram predictor including eight variables—age, sex, grade, T, N, M, surgery, and chemotherapy—is constructed. The predictor provides good performance in discrimination and calibration, with area under the curve ≥0.8 in the receiver operating characteristic curves of both internal and external validations. The predictor especially had very good clinical utility in terms of net benefit to patients at the 3- and 5-year points in both North America and China. A convenient web calculator based on the prediction model is available at https://drwenle029.shinyapps.io/CHSSapp, which is free and open to all clinicians.

Clinical Characteristics, Prognostic Factor and a Novel Dynamic Prediction Model for Overall Survival of Elderly Patients With Chondrosarcoma: A Population-Based Study

Background

Chondrosarcoma is the most common primary bone sarcoma among elderly population. This study aims to explore independent prognostic factors and develop prediction model in elderly patients with CHS.

Methods

This study retrospectively analyzed the clinical data of elderly patients diagnosed as CHS between 2004 and 2018 from the Surveillance, Epidemiology, and End Results (SEER) database. We randomly divided enrolled patients into training and validation group, univariate and multivariate Cox regression analyses were used to determine independent prognostic factors. Based on the identified variables, the nomogram was developed and verified to predict the 12-, 24-, and 36-month overall survival (OS) of elderly patients with CHS. A k-fold cross-validation method (k=10) was performed to validate the newly proposed model. The discrimination, calibration and clinical utility of the nomogram were assessed using the Harrells concordance index (C-index), receiver operating characteristic (ROC) curve and the area under the curve (AUC), calibration curve, decision curve analysis (DCA), the integrated discrimination improvement (IDI) and net reclassification index (NRI). Furthermore, a web-based survival calculator was developed based on the nomogram.

Results

The study finally included 595 elderly patients with CHS and randomized them into the training group (419 cases) and validation group (176 cases) at a ratio of 7:3. Age, sex, grade, histology, M stage, surgery and tumor size were identified as independent prognostic factors of this population. The novel nomogram displayed excellent predictive performance, which can be accessible by https://nomoresearch.shinyapps.io/elderlywithCHS/, with a C-index of 0.800 for the training group and 0.789 for the validation group. The value AUC values at 12-, 24-, and 36-month of 0.866, 0.855, and 0.860 in the training group and of 0.839, 0.856, and 0.840 in the validation group, respectively. The calibration curves exhibited good concordance from the predicted survival probabilities to actual observation. The ROC curves, IDI, NRI, and DCA showed the nomogram was superior to the existing AJCC staging system.

Conclusion

This study developed a novel web-based nomogram for accurately predicting probabilities of OS in elderly patients with CHS, which will contribute to personalized survival assessment and clinical management for elderly patients with CHS.

Multifunctional mesoporous silica nanoparticles for pH-response and photothermy enhanced osteosarcoma therapy

The recurrence and bone defect of malignant osteosarcoma postsurgical treatment have gained remarkable attention. Therefore, the development of multifunctional treatment platform is urgently desirable to achieve efficient tumor treatment and bone regeneration. In this paper, a multifunctional nanomaterial using mesoporous silica (MSN) as platform modified with quercetin (Qr), collagen (Col) and dopamine (PDA) was developed. Our findings demonstrated that the nanoparticles designed in this work had excellent photothermal properties and pH responsiveness. In addition, the nanoparticles had outstanding anti-tumor ability and could killed Saos-2 cells within 10 min under 808 nm laser irradiation owing to the synergistic effect of hyperthermia and Qr. Besides, the modification of PDA and Col endows the nanoparticles with excellent osteogenic activity.

Dedifferentiated Chondrosarcoma: A Case Series and Review of the Literature

BACKGROUND

Dedifferentiated chondrosarcoma (DCS) is a rare and aggressive malignancy with a poor prognosis. The purpose of this investigation was to describe our treatment and outcomes of 16 DCS patients at our institution and provide a review of the current literature.

METHODS

This study was a retrospective review over a consecutive twenty-year period. Data including treatment details and outcomes were recorded.

RESULTS

A total of 16 cases from 2000 to 2018 were identified. The median age (IQR) was 62 years (52; 69) and the majority of DCS arose in the femur (50%, n=8) and pelvis (25%, n=4). Fourteen (88%) cases underwent limb salvage/wide margin resection (n=13) or intralesional surgery (n=1). For all DCS, the median survival (IQR) was 46 months (12; 140), with both a five and ten-year probability of 32.1% (95% CI, 7.3% to 57.0%). At study conclusion, 81.3% (n=13) were deceased and 18.7% (n=3) were alive.

CONCLUSIONS

Our findings confirm the poor prognosis of DCS patients, with a five-year estimate of 32%. Together with existing literature, our data might help enable future strategic recommendation of these patients.

Mesenchymal chondrosarcoma: An Australian multi-centre cohort study

BACKGROUND

Mesenchymal chondrosarcoma (MCS) is an ultra-rare sarcoma that follows a more aggressive course than conventional chondrosarcoma. This study evaluates prognostic factors, treatments (surgery, chemotherapy, and radiation), and outcomes in an Australian setting.

METHODS

We collected demographics, clinicopathological variables, treatment characteristics, and survival status from patients with MCS registered on the national ACCORD sarcoma database. Outcomes include overall survival (OS) and progression-free survival (PFS).

RESULTS

We identified 22 patients with MCS between 2001-2022. Median age was 28 (range 10-59) years, 19 (86%) had localised disease at diagnosis of whom 16 had surgery (84%), 11 received radiation (58%), and 10 chemotherapy (53%). Ten (52%) developed recurrence and/or metastases on follow-up and three patients with initial metastatic disease received surgery, radiation, and chemotherapy. At a median follow-up of 50.9  (range 0.4-210) months nine patients had died. The median OS was 104.1 months (95% CI 25.8-182.3). There was improved OS for patients with localised disease who had surgical resection of the primary (p = 0.003) and those with ECOG 0-1 compared to 2-3 (p = 0.023) on univariate analysis.

CONCLUSIONS

This study demonstrates contemporary Australian treatment patterns of MCS. The role of chemotherapy for localised disease remains uncertain. Understanding treatment patterns and outcomes help support treatment decisions and design of trials for novel therapeutic strategies.

Management of Unresectable Localized Pelvic Bone Sarcomas: Current Practice and Future Perspectives

Simple Summary

Some locally advanced pelvic bone tumors are deemed unresectable and, as such, not suitable for curative surgery. In this setting, treatment options are generally limited and not unanimous, with decisions being made on an individual basis after multidisciplinary discussion. Ultimately, and notwithstanding the bright prospects raised by novel therapeutic approaches, treatment should be patient-tailored, weighing a panoply of patient- and tumor-related factors.

Abstract

Bone sarcomas (BS) are rare mesenchymal tumors usually located in the extremities and pelvis. While surgical resection is the cornerstone of curative treatment, some locally advanced tumors are deemed unresectable and hence not suitable for curative intent. This is often true for pelvic sarcoma due to anatomic complexity and proximity to vital structures, making treatment options for these tumors generally limited and not unanimous, with decisions being made on an individual basis after multidisciplinary discussion. Several studies have been published in recent years focusing on innovative treatment options for patients with locally advanced sarcoma not amenable to local surgery. The present article reviews the evidence regarding the treatment of patients with locally advanced and unresectable pelvic BS, with the goal of providing an overview of treatment options for the main BS histologic subtypes involving this anatomic area and exploring future therapeutic perspectives. The management of unresectable localized pelvic BS represents a major challenge and is hampered by the lack of comprehensive and standardized guidelines. As such, the optimal treatment needs to be individually tailored, weighing a panoply of patient- and tumor-related factors. Despite the bright prospects raised by novel therapeutic approaches, the role of each treatment option in the therapeutic armamentarium of these patients requires solid clinical evidence before becoming fully established.

SELNET clinical practice guidelines for bone sarcoma

Bone sarcoma are infrequent diseases, representing < 0.2% of all adult neoplasms. A multidisciplinary management within reference centers for sarcoma, with discussion of the diagnostic and therapeutic strategies within an expert multidisciplinary tumour board, is essential for these patients, given its heterogeneity and low frequency. This approach leads to an improvement in patient's outcome, as demonstrated in several studies. The Sarcoma European Latin-American Network (SELNET), aims to improve clinical outcome in sarcoma care, with a special focus in Latin-American countries. These Clinical Practice Guidelines (CPG) have been developed and agreed by a multidisciplinary expert group (including medical and radiation oncologist, surgical oncologist, orthopaedic surgeons, radiologist, pathologist, molecular biologist and representatives of patients advocacy groups) of the SELNET consortium, and are conceived to provide the standard approach to diagnosis, treatment and follow-up of bone sarcoma patients in the Latin-American context.

Case report on the approach to surgical management for a large chest wall chondrosarcoma

Introduction and importance

Primary chest wall tumours are uncommon. Challenges arise in management due to delays in diagnosis and timing of treatment. The mainstay of treatment remains complete resection as adjuvant therapy has a limited role. Choice of repair and materials for chest wall reconstruction vary depending on the size and location of the defect. There are no published reports on management of chondrosarcomas arising from the rib in the Caribbean.

Case presentation

A 61-year-old female was referred from a rural clinic with a 10-month history of a progressively enlarging, painless right anterior chest wall lump. Computed Tomography (CT) shows features of a conventional chondrosarcoma arising from the ribs and including surrounding soft tissue, muscle and pleura. Surgical specimen confirms a grade 2 chondrosarcoma.

Clinical discussion

This case illustrates the importance of a multidisciplinary team discussion. Differentiating a chondrosarcoma from a benign cartilaginous tumour requires consideration of clinical features, radiological characteristics and histological features. Chest wall reconstruction aims to preserve functional and structural integrity with adequate soft tissue coverage. The patient had good cosmesis as well as pulmonary function postoperatively and no recurrence at the 3 year follow up.

Conclusion

This case highlights that the MDT is essential to a good outcome for the surgical management of a chest wall chondrosarcoma. Wide en-bloc resection followed by reconstruction using polypropylene mesh and a latissimus dorsi flap as a one-stage procedure can be successful.

•

Primary Chest wall tumors are uncommon.

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Chondrosarcomas less commonly occur in the chest wall, accounting for 15% of cases.

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Diagnosis and management can be challenging- a Multi- Disciplinary Team approach is required.

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Treatment remains surgical as chemotherapy has a limited role.

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Chest wall reconstruction can be done as a single-step surgical procedure using synthetic mesh and autologous muscle flap.

Is Chemotherapy Associated with Improved Overall Survival in Patients with Dedifferentiated Chondrosarcoma? A SEER Database Analysis

BACKGROUND

Dedifferentiated chondrosarcoma is a chondrosarcoma subtype associated with high rates of recurrence and a poor prognosis. Others have proposed treatment of dedifferentiated chondrosarcoma using osteosarcoma protocols, including perioperative chemotherapy. However, the rarity of this condition poses difficulties in undertaking single- institution studies of sufficient sample size.

QUESTION/PURPOSE

Is perioperative chemotherapy associated with improved overall survival in patients with dedifferentiated chondrosarcoma?

METHODS

We queried the Surveillance, Epidemiology, and End Results (SEER) 1973 to 2016 database for patients with a diagnosis of dedifferentiated chondrosarcoma (n = 308). As dedifferentiated chondrosarcoma was only classified as a distinct entity in SEER starting in 2000, only patients treated in 2000 and later were included. We excluded from our analyses those patients with distant disease at diagnosis, a primary site of disease other than bone or joints, and those who did not receive cancer-directed surgery. These criteria yielded 185 dedifferentiated chondrosarcoma patients for inclusion. We used Kaplan-Meier analyses and Cox proportional hazards models to assess the association of clinical, demographic, and treatment characteristics on overall survival (OS).

RESULTS

After controlling for confounding variables, including age, sex, tumor size, stage, grade, location, and radiation treatment status, and after adjusting for missing data, no overall survival benefit was associated with receipt of chemotherapy in patients with dedifferentiated chondrosarcoma (hazard ratio 0.75 [95% confidence interval 0.49 to 1.12]; p = 0.16).

CONCLUSION

Chemotherapy treatment of dedifferentiated chondrosarcoma was not associated with improved OS. These results must be viewed cautiously, given the limited granularity of information on chemotherapy treatment, the concerns regarding chemotherapy misclassification in SEER data, and the small sample of patients with dedifferentiated chondrosarcoma, all of which limit the power to detect a difference. Our findings are nevertheless consistent with those of prior reports in which no benefit of chemotherapy could be detected. Lack of clear benefit from perioperative chemotherapy in dedifferentiated chondrosarcoma argues that it should be used only after careful consideration, and ideally in the context of a clinical trial.

LEVEL OF EVIDENCE

Level III, therapeutic study.

A bone implant with NIR-responsiveness for eliminating osteosarcoma cells and promoting osteogenic differentiation of BMSCs

Incomplete removal of tumor cells and insufficient osseointegration are the main causes of bone tumor recurrence and implantation failure. In the present study, a multifunctional titanium-based bioactive implant for near-infrared-triggered synergy therapy to overcome these hurdles is engineered, composed of titanium dioxide (TiO₂) nanoparticles doped with fluorine (F)/dopamine (PDA)/collagen. The TiO₂ nanoparticles designed in this work can simultaneously exhibit excellent near-infrared-activated photothermal and photocatalytic properties. Besides, the layer designed in this work show excellent anti-tumor activity under irradiation with 808 nm light due to the synergetic effect of hyperthermia and reactive oxygen species (ROS), and Saos-2 cells can be eradicated within 10 min. Moreover, modification of PDA and collagen endue the Ti alloy excellent osteogenic activity.

Radiosensitizing Effect of Celastrol by Inhibiting G2/M Phase Arrest Induced by the c-myc Gene of Human SW1353 Chondrosarcoma Cells: Network and Experimental Analyses

Objective

Studies have unveiled that the components of Tripterygium wilfordii Hook F (TWHF) such as celastrol could attenuate apoptosis and proliferation of various tumor cells. This study is focused on the radiosensitization effect and apoptotic pathways of celastrol via the inhibition of the c-myc gene and the influence of which combined with radiotherapy on the proliferation, apoptosis, invasion, and metastasis of chondrosarcoma cells.

Methods

A variety of bioinformatic tools were applied to explore the expression level and prognosis of the c-myc gene in different tumor cells and chondrosarcoma cells. We used pharmacology network to analyze the components, pathways, targets, molecular functions of TWHF and explore the relevant effective components over the MYC gene. Clone formation assay, CCK-8 assay, flow cytometry, and transwell migration assay were applied to detect the effects of celastrol on the expression of c-myc gene, cell apoptosis, and cell cycle. Radiation therapy was used to observe the radiosensitization effect of celastrol on chondrosarcoma.

Results

This study shows that the c-myc gene is overexpressed in various tumor cells and bone tumor cells to varying degrees. Celastrol can significantly inhibit the expression of the c-myc gene, induce G2/M phase arrest through regulation of G2/M phase-related proteins, and promote SW1353 cell apoptosis through the mitochondrial signaling pathway. In addition, we also found that the use of triptorubin to inhibit c-myc gene expression in combination with radiotherapy can increase the osteosarcoma cells' apoptosis rate through the mitochondrial signaling pathway significantly.

Conclusions

Our study validated the radiosensitization effect of celastrol through knocking down the expression of the c-myc gene to induce G2/M phase arrest and provides a new idea for the treatment of refractory or recurrent chondrosarcoma that is not sensitive to radiotherapy.

Therapeutic Targets and Emerging Treatments in Advanced Chondrosarcoma

Due to resistance to standard anticancer agents, it is difficult to control the disease progression in patients with metastatic or unresectable chondrosarcoma. Novel therapeutic approaches, such as molecule-targeting drugs and immunotherapy, are required to improve clinical outcomes in patients with advanced chondrosarcoma. Recent studies have suggested several promising biomarkers and therapeutic targets for chondrosarcoma, including IDH1/2 and COL2A1. Several molecule-targeting agents and immunotherapies have shown favorable antitumor activity in clinical studies in patients with advanced chondrosarcomas. This review summarizes recent basic studies on biomarkers and molecular targets and recent clinical studies on the treatment of chondrosarcomas.

Clinical development of IDH1 inhibitors for cancer therapy

Isocitrate dehydrogenase 1 (IDH1) has been investigated as a promising therapeutic target in select cancers with a mutated version of the enzyme (mtIDH1). With only one phase III trial published to date and two indications approved for routine clinical use by the FDA, we reviewed the entire clinical trial portfolio to broadly understand mtIDH1 inhibitor activity in patients. We queried PubMed.gov and ClinicalTrials.gov to identify published and ongoing clinical trials related to IDH1 and cancer. Progression-free survival (PFS), overall survival (OS), 2-hydroxyglutarate levels, and adverse events were summarized. To date, ten clinical trials investigating mtIDH1 inhibitors among patients with diverse malignancies (cholangiocarcinoma, acute myeloid leukemia, chondrosarcoma, glioma) have been published. Almost every trial (80%) has investigated ivosidenib. In multiple phase I trials, ivosidenib treatment resulted in promising radiographic and biochemical responses with improved survival outcomes (relative to historic data) among patients with both solid and hematologic mtIDH1 malignancies. Among patients enrolled in a phase III trial with advanced cholangiocarcinoma, ivosidenib resulted in a PFS rate of 32% at 6 months, as compared to 0% with placebo. There was a 5.2 month increase in OS with ivosidenib relative to placebo, after considering crossover. The treatment-specific grade ≥3 adverse event rate of ivosidenib was 2%-26% among all patients, and was just 3.6% among 284 patients who had a solid tumor across four trials. Although <1% of malignancies harbor IDH1 mutations, small molecule mtIDH1 inhibitors, namely ivosidenib, appear to be biologically active and well tolerated in patients with solid and hematologic mtIDH1 malignancies.

Metabolic Pathways and Targets in Chondrosarcoma

Chondrosarcomas are the second most common primary bone malignancy. Chondrosarcomas are characterized by the production of cartilaginous matrix and are generally resistant to radiation and chemotherapy and the outcomes are overall poor. Hence, there is strong interest in determining mechanisms of cancer aggressiveness and therapeutic resistance in chondrosarcomas. There are metabolic alterations in chondrosarcoma that are linked to the epigenetic state and tumor microenvironment that drive treatment resistance. This review focuses on metabolic changes in chondrosarcoma, and the relationship between signaling via isocitrate dehydrogenase 1 and 2 (IDH1 and IDH2), hedgehog, PI3K-mTOR-AKT, and SRC, as well as histone acetylation and angiogenesis. Also, potential treatment strategies targeting metabolism will be discussed including potential synergy with immunotherapies.

Advances in Filament Structure of 3D Bioprinted Biodegradable Bone Repair Scaffolds

Conventional bone repair scaffolds can no longer meet the high standards and requirements of clinical applications in terms of preparation process and service performance. Studies have shown that the diversity of filament structures of implantable scaffolds is closely related to their overall properties (mechanical properties, degradation properties, and biological properties). To better elucidate the characteristics and advantages of different filament structures, this paper retrieves and summarizes the state of the art in the filament structure of the three-dimensional (3D) bioprinted biodegradable bone repair scaffolds, mainly including single-layer structure, double-layer structure, hollow structure, core-shell structure and bionic structures. The eximious performance of the novel scaffolds was discussed from different aspects (material composition, ink configuration, printing parameters, etc.). Besides, the additional functions of the current bone repair scaffold, such as chondrogenesis, angiogenesis, anti-bacteria, and anti-tumor, were also concluded. Finally, the paper prospects the future material selection, structural design, functional development, and performance optimization of bone repair scaffolds.

Malignant Cartilage-Forming Tumors

Chondrosarcomas are heterogeneous matrix-producing cartilaginous neoplasms with variable clinical behavior. Subtypes include conventional (75%), dedifferentiated (10%), clear cell (2%), mesenchymal (2%), and periosteal chondrosarcoma (<1%). Tumor location and primary vs secondary also play a role. In conventional chondrosarcoma, histologic grading (I, II, and III) remains the gold standard for predicting recurrence and metastases. Due to the locally aggressive but overall nonmetastatic behavior, grade I chondrosarcomas (primary and secondary) of long and short tubular bones have been reclassified as atypical cartilaginous tumor. In this review, the pathologic features of malignant cartilage tumors are discussed with updates on recent genetic findings.

Dedifferentiated chondrosarcoma: current standards of care

Dedifferentiated chondrosarcomas are aggressive variants of chondrosarcoma, associated with poor outcomes. Tumor biphasism is the norm. The majority of these tumors are symptomatic at presentation. Radiologically, large soft tissue masses with bony destruction predominate. Treatment protocols of these tumors are not well defined. Surgical resection forms the standard of care for localized disease. (Neo)adjuvant therapies remain controversial as the results from multiple (mainly retrospective) studies remain conflicting. Age at presentation, stage and ability to obtain negative resection margins are important prognostic factors. The overall prognosis is dismal. Newer and novel therapies targeting the complex genetic makeup of these tumors have renewed interest in the adjuvant setting that could hold promise in the near future.

Progress of Phototherapy Applications in the Treatment of Bone Cancer

Bone cancer including primary bone cancer and metastatic bone cancer, remains a challenge claiming millions of lives and affecting the life quality of survivors. Conventional treatments of bone cancer include wide surgical resection, radiotherapy, and chemotherapy. However, some bone cancer cells may remain or recur in the local area after resection, some are highly resistant to chemotherapy, and some are insensitive to radiotherapy. Phototherapy (PT) including photodynamic therapy (PDT) and photothermal therapy (PTT), is a clinically approved, minimally invasive, and highly selective treatment, and has been widely reported for cancer therapy. Under the irradiation of light of a specific wavelength, the photosensitizer (PS) in PDT can cause the increase of intracellular ROS and the photothermal agent (PTA) in PTT can induce photothermal conversion, leading to the tumoricidal effects. In this review, the progress of PT applications in the treatment of bone cancer has been outlined and summarized, and some envisioned challenges and future perspectives have been mentioned. This review provides the current state of the art regarding PDT and PTT in bone cancer and inspiration for future studies on PT.

Tracheal chondrosarcoma: A case report, systematic review, and pooled analysis

Background

Tracheal chondrosarcoma is a rare malignancy, and formal treatment guidelines have not been established due to the lack of high quality studies. Best evidence at this time is limited to case reports.

Aim

Explore the role of surgical intervention, radiation therapy, and chemotherapy, and the long‐term outcomes for these interventions for tracheal chondrosarcoma.

Methods and Results

A literature search was performed using PubMed (1959–2020) and ResearchGate (1959–2020) using medical subject heading terms “tracheal chondrosarcoma” OR “trachea chondrosarcoma.” Additional reports were identified within reviewed articles and included for review. Articles pertaining to chondrosarcomas of the lung, bronchus, larynx, or other head and neck subsites were excluded. Cases of chondromas were excluded. Thirty‐five patients with tracheal chondrosarcoma were identified in the literature since 1959. Advanced age was significantly associated with recurrent or persistent disease (p = .003). The majority (77%) of cases were treated with open surgical resection, with an open approach and negative surgical margins being significantly associated with being disease‐free after treatment (p = .001 and p < .001, respectively). Adjuvant radiotherapy was reserved for those unfit for surgery or for recurrent disease. Tumor size, extra‐tracheal extension, tumor calcification, location, and initial diagnosis were not associated with tumor recurrence.

Conclusion

Non‐metastatic tracheal chondrosarcoma can be treated by adequate surgical resection, with little to no role for adjuvant radiotherapy or chemotherapy. Open surgery and negative margins were associated with oncologic control, while advanced age was associated with recurrent or persistent disease.

Survival and Scoliosis Following Resection of Chest Wall Tumors in Children and Adolescents: A Single-center Retrospective Analysis

OBJECTIVE

We reviewed our experience with pediatric chest wall tumors (CWTs) to identify variables associated with survival, scoliosis development, and need for corrective scoliosis surgery.

BACKGROUND

Chest wall neoplasms in children or adolescents are rare. Consequently, there are few large series that detail survival or quality of life indicators, like scoliosis.

METHODS

Medical records were reviewed for all chest wall resections for primary and metastatic CWT performed from October 1, 1986 to September 30, 2016 on patients 21 years or younger at diagnosis. Kaplan-Meier distributions were compared using the log-rank test. Variables correlated with survival, scoliosis development, or need for corrective surgeries were analyzed using competing-risk analysis.

RESULTS

Seventy-six cases [57 (75%) primary, 19 (25%) metastatic] were identified. Median age at diagnosis was 15.6 years (range: 0.5-21 years). Tumor types were Ewing sarcoma family tumors (54%), other soft tissue sarcomas (21%), osteosarcoma (11%), rhabdomyosarcoma (7%), and other (8%). A median of 3 (range: 1-5) contiguous ribs were resected. Surgical reconstruction included composite Marlex mesh and methyl-methacrylate, Gore-Tex, or primary closure in 57%, 28%, and 14% of procedures, respectively. Overall 5-year survival was 61% (95% confidence interval: 50%-75%). Scoliosis developed in 19 (25%) patients; 6 patients required corrective surgery. Variables associated with overall survival were the presence of metastatic disease at diagnosis, and whether the chest tumor itself was a primary or metastatic lesion. Younger age at chest wall resection was associated with the need for corrective surgery in patients who developed scoliosis.

CONCLUSIONS

Among pediatric and adolescent patients with CWTs, survival depends primarily on the presence of metastases. Age, type of chest wall reconstruction, and tumor size are not associated with scoliosis development. Among patients who develop scoliosis, younger patients are more likely to require corrective surgery.