Revisiting the Role of Radiation Therapy in Chondrosarcoma: A National Cancer Database Study

Risk calculator for long-term survival prediction of spinal chordoma versus chondrosarcoma: a nationwide analysis

PURPOSE

Chordomas and chondrosarcomas are rare, aggressive spinal bone tumors with distinct origins, biological behavior, and treatment challenges, primarily due to their resistance to conventional chemotherapy and radiation. This study aimed to compare clinical characteristics, treatment strategies, and long-term outcomes between spinal chordoma and chondrosarcoma, and to develop a robust machine learning-based model for individualized survival prediction.

METHODS

We conducted a retrospective analysis using the National Cancer Database (NCDB) to identify patients diagnosed with spinal chordoma or chondrosarcoma from 2004 to 2017. Demographics, tumor characteristics, comorbidity indices, treatment modalities (surgery, radiation, chemotherapy), and outcomes were extracted. Kaplan-Meier and weighted log-rank analyses assessed overall survival (OS) at predefined intervals (30-day, 90-day, 1-year, 5-year, 10-year). Twelve machine learning and deep learning models were trained to predict 10-year OS. Model performance was evaluated using AUC, Brier Score, and Concordance Index (C-index). A web-based risk calculator was developed using the best-performing ensemble model.

RESULTS

A total of 3175 patients were included (chordoma: n = 1204; chondrosarcoma: n = 1971). Chordoma patients were significantly older, travelled farther for treatment, and had smaller tumors with lower rates of metastatic disease at presentation. Chondrosarcoma patients more frequently underwent gross total resection, while chordoma patients received more radiation therapy, often with higher doses and more frequent use of proton therapy. Kaplan-Meier analysis revealed that chordoma patients had superior 10-year OS compared to chondrosarcoma patients (p < 0.0001). Among those receiving radiation, chondrosarcoma patients treated with radiation alone had the poorest survival. DeepSurv achieved the highest C-index (0.83) and lowest Brier Score (0.14), while ensemble models integrating Gradient Boosting and CatBoost also demonstrated strong performance (AUC > 0.80). Age, tumor type, and radiation therapy were identified as the most influential predictors using SHAP analysis. A publicly accessible, web-based calculator was developed for individualized survival prediction.

CONCLUSION

Spinal chordoma and chondrosarcoma differ significantly in clinical features and outcomes, with chordoma showing more favorable long-term survival. The findings highlight the importance of GTR and individualized radiation therapy in optimizing outcomes. The predictive model employing complicated machine learning models provides a valuable tool for estimating long-term survival and guiding personalized treatment strategies, though external validation is needed to strengthen its generalizability and clinical utility.

UK guidelines for the management of bone sarcomas

This document is an update of the British Sarcoma Group guidelines (2016) and provides a reference standard for the clinical care of UK patients with primary malignant bone tumours (PMBT) and giant cell tumours (GCTB) of bone. The guidelines recommend treatments that are effective and should be available in the UK, and support decisions about management and service delivery. The document represents a consensus amongst British Sarcoma Group members in 2024. Key recommendations are that bone pain, or a palpable mass should always lead to further investigation and that patients with clinical or radiological findings suggestive of a primary bone tumour at any anatomic site should be referred to a specialist centre and managed by an accredited bone sarcoma multidisciplinary team. Treatment recommendations are provided for the major tumour types and for localised, metastatic and recurrent disease. Follow-up schedules are suggested.

Chondrosarcoma of the Mobile Spine: An Update on Patients Treated at a Single Institution

STUDY DESIGN

Retrospective study.

OBJECTIVE

The objective of this study was to report the clinical data for patients treated with mobile spine chondrosarcoma.

SUMMARY OF BACKGROUND DATA

Chondrosarcoma of the mobile spine is a rare and challenging entity. A handful of case series have been published that report the clinical results of treatment, largely influenced by chondrosarcoma of the appendicular skeleton and pelvis. The clinical results of patients treated for chondrosarcoma of the mobile spine from our institution were published over 10 years ago and this represents and update since that publication.

METHODS

Inclusion criteria were adults patients treated for chondrosarcoma of the mobile spine at Massachusetts General Hospital between 2007 and 2020. Patients with large sacral tumors extending into the lumbar spine were excluded. Furthermore, we excluded patients with metastatic chondrosarcoma undergoing palliative decompressions for neurological instability or instrumented procedures for biomechanical instability. Therefore, only patients undergoing definitive surgery at the primary site of disease in the mobile spine were included.

RESULTS

A total of 24 patients were included for review in this series. Seventeen of the 24 patients had their tumors excised with negative (R0) margins. Three of these 17 patients (18%) were dead of disease at final follow-up. There were two patients with R1 resections and five patients with R2 resections. Three of the seven patients (43%) with positive margins were dead of disease at final follow-up. A Cox proportional hazard analysis indicated total radiation dose was a significant covariate (HR=1.18, 95% CI: 1.01-1.39, P =0.03).

CONCLUSIONS

We found higher percentages of overall survival with R0 tumor resection and lower histologic grade, whereas development of metastatic disease was closely associated with local recurrence and poor survival. Despite the improvements in treatment paradigms, it is sobering that our findings largely mirror those of previous work considering patients treated between 1984 and 2006.

Enhancing Proton Radiosensitivity of Chondrosarcoma Using Nanoparticle-Based Drug Delivery Approaches: A Comparative Study of High- and Low-Energy Protons

To overcome chondrosarcoma's (CHS) high chemo- and radioresistance, we used polyethylene glycol-encapsulated iron oxide nanoparticles (IONPs) for the controlled delivery of the chemotherapeutic doxorubicin (IONPDOX) to amplify the cytotoxicity of proton radiation therapy. Human 2D CHS SW1353 cells were treated with protons (linear energy transfer (LET): 1.6 and 12.6 keV/µm) with and without IONPDOX. Cell survival was assayed using a clonogenic test, and genotoxicity was tested through the formation of micronuclei (MN) and γH2AX foci, respectively. Morphology together with spectral fingerprints of nuclei were measured using enhanced dark-field microscopy (EDFM) assembled with a hyperspectral imaging (HI) module and an axial scanning fluorescence module, as well as scanning electron microscopy (SEM) coupled with energy-dispersive X-Ray spectroscopy (EDX). Cell survival was also determined in 3D SW3153 spheroids following treatment with low-LET protons with/without the IONPDOX compound. IONPDOX increased radiosensitivity following proton irradiation at both LETs in correlation with DNA damage expressed as MN or γH2AX. The IONPDOX-low-LET proton combination caused a more lethal effect compared to IONPDOX-high-LET protons. CHS cell biological alterations were reflected by the modifications in the hyperspectral images and spectral profiles, emphasizing new possible spectroscopic markers of cancer therapy effects. Our findings show that the proposed treatment combination has the potential to improve the management of CHS.

Spinal chordoma and chondrosarcoma treatment experiences - a 20-year retrospective study from databases of two medical centers

The research retrospectively analyzed cases of spinal chordoma and chondrosarcoma involving patients who received treatment at the two hospitals between 2001 and 2023. Among the 48 patients studied (39 chordoma and 9 chondrosarcoma cases), the average age was 53.9 ± 15.8 years, with a range of 17 to 86 years. Out of these patients, 43 underwent excision surgery and were categorized based on tumor margin into negative (R0) or microscopically positive (R1) margin (n = 14) and macroscopically positive (R2) margin (n = 29) groups. The mean overall survival (OS) for R0/R1 and R2 groups was 156.5 ± 19.3 and 79.2 ± 11.9 months, respectively (p value = 0.012). The mean progression-free survival (PFS) for R0/R1 and R2 was 112.9 ± 24.4 and 25.5 ± 5.5 months (p value < 0.001). The study showed that regardless of whether patients in the R0/R1 or R2 groups received radiation therapy (RT) or not, there was no significant improvement in OS or PFS. Specifically, the OS and PFS for the RT only group were 75.9 ± 16.6 and 73.3 ± 18.0 months. In conclusion, the recommended treatment approach for spinal chordoma and chondrosarcoma remains en bloc resection surgery with an appropriate margin. Patients who are unsuitable for or decline surgery may find a beneficial disease control rate with traditional external beam photon/proton therapy.

Emerging Treatments Targeting the Tumor Microenvironment for Advanced Chondrosarcoma

Chondrosarcoma (ChS), a malignant cartilage-producing tumor, is the second most frequently diagnosed osseous sarcoma after osteosarcoma. It represents a very heterogeneous group of malignant chemo- and radiation-resistant neoplasms, accounting for approximately 20% of all bone sarcomas. The majority of ChS patients have a good prognosis after a complete surgical resection, as these tumors grow slowly and rarely metastasize. Conversely, patients with inoperable disease, due to the tumor location, size, or metastases, represent a great clinical challenge. Despite several genetic and epigenetic alterations that have been described in distinct ChS subtypes, very few therapeutic options are currently available for ChS patients. Therefore, new prognostic factors for tumor progression as well as new treatment options have to be explored, especially for patients with unresectable or metastatic disease. Recent studies have shown that a correlation between immune infiltrate composition, tumor aggressiveness, and survival does exist in ChS patients. In addition, the intra-tumor microvessel density has been proven to be associated with aggressive clinical behavior and a high metastatic potential in ChS. This review will provide an insight into the ChS microenvironment, since immunotherapy and antiangiogenic agents are emerging as interesting therapeutic options for ChS patients.

Head and Neck Low Grade Chondrosarcoma-A Rare Entity

Chondrosarcoma represents approximately 0.1% of all neoplasms of the head and neck and is considered a rare disease with a relatively good prognosis. The 5-year overall survival (OS) rate is estimated at 70-80%, being considered a disease with a low growth rate. Approximately 13% of all cases of chondrosarcoma are located in the region of the head and neck. We present the case of a 30-year-old patient without a medical history who reported dysphagia, swallowing difficulty, neck mass sensation and dysphonia that started insidiously after an upper respiratory tract infection. Subsequently, the patient was diagnosed with a low-grade glosso-epiglottic region chondrosarcoma and was multimodally treated with surgery followed by chemotherapy and radiotherapy. The radiation treatment was delivered with a Rokus M40 former Soviet Union cobalt machine without any image guidance capabilities. The inability to obtain resection margin information justified an aggressive adjuvant treatment with chemotherapy and radiotherapy. The early loss from the oncological record without recurrence of the disease could be associated in this case with the consequence of a major complication, of which we could assume an aspiration pneumonia secondary to a dysphagia associated with an aggressive multidisciplinary treatment. Large tumor size and positive resection margins (R1 resection) are risk factors that support an intensive adjuvant approach in order to reduce the risk of recurrence, but the low grade of tumor associated with a lower risk of recurrence as well as the adverse events (AE) of adjuvant radiotherapy and chemotherapy justify a more reserved therapeutic approach. Taking into account the longer life expectancy of these patients, it is recommended to use a more conformal irradiation technique in order to reduce doses to radiosensitive structures as well as to omit elective neck irradiation, taking into account the lower risk of lymph node involvement. The lack of guidelines, which include very rare tumors including low grade chondrosarcoma of the head and neck, makes a unified approach difficult, but the data presented in case reports could contribute to choosing the regimen that offers the best therapeutic ratio.

In vitro hyperspectral biomarkers of human chondrosarcoma cells in nanoparticle-mediated radiosensitization using carbon ions

New therapeutic approaches are needed for the management of the highly chemo- and radioresistant chondrosarcoma (CHS). In this work, we used polyethylene glycol-encapsulated iron oxide nanoparticles for the intracellular delivery of the chemotherapeutic doxorubicin (IONPDOX) to augment the cytotoxic effects of carbon ions in comparison to photon radiation therapy. The in vitro biological effects were investigated in SW1353 chondrosarcoma cells focusing on the following parameters: cell survival using clonogenic test, detection of micronuclei (MN) by cytokinesis blocked micronucleus assay and morphology together with spectral fingerprints of nuclei using enhanced dark-field microscopy (EDFM) assembled with a hyperspectral imaging (HI) module. The combination of IONPDOX with ion carbon or photon irradiation increased the lethal effects of irradiation alone in correlation with the induction of MN. Alterations in the hyperspectral images and spectral profiles of nuclei reflected the CHS cell biological modifications following the treatments, highlighting possible new spectroscopic markers of cancer therapy effects. These outcomes showed that the proposed combined treatment is promising in improving CHS radiotherapy.

Radiotherapy in bone sarcoma: the quest for better treatment option

Bone sarcomas are rare tumors representing 0.2% of all cancers. While osteosarcoma and Ewing sarcoma mainly affect children and young adults, chondrosarcoma and chordoma have a preferential incidence in people over the age of 40. Despite this range in populations affected, all bone sarcoma patients require complex transdisciplinary management and share some similarities. The cornerstone of all bone sarcoma treatment is monobloc resection of the tumor with adequate margins in healthy surrounding tissues. Adjuvant chemo- and/or radiotherapy are often included depending on the location of the tumor, quality of resection or presence of metastases. High dose radiotherapy is largely applied to allow better local control in case of incomplete primary tumor resection or for unresectable tumors. With the development of advanced techniques such as proton, carbon ion therapy, radiotherapy is gaining popularity for the treatment of bone sarcomas, enabling the delivery of higher doses of radiation, while sparing surrounding healthy tissues. Nevertheless, bone sarcomas are radioresistant tumors, and some mechanisms involved in this radioresistance have been reported. Hypoxia for instance, can potentially be targeted to improve tumor response to radiotherapy and decrease radiation-induced cellular toxicity. In this review, the benefits and drawbacks of radiotherapy in bone sarcoma will be addressed. Finally, new strategies combining a radiosensitizing agent and radiotherapy and their applicability in bone sarcoma will be presented.

Chondrosarcoma Resistance to Radiation Therapy: Origins and Potential Therapeutic Solutions

Chondrosarcoma is a malignant cartilaginous tumor that is particularly chemoresistant and radioresistant to X-rays. The first line of treatment is surgery, though this is almost impossible in some specific locations. Such resistances can be explained by the particular composition of the tumor, which develops within a dense cartilaginous matrix, producing a resistant area where the oxygen tension is very low. This microenvironment forces the cells to adapt and dedifferentiate into cancer stem cells, which are described to be more resistant to conventional treatments. One of the main avenues considered to treat this type of tumor is hadrontherapy, in particular for its ballistic properties but also its greater biological effectiveness against tumor cells. In this review, we describe the different forms of chondrosarcoma resistance and how hadrontherapy, combined with other treatments involving targeted inhibitors, could help to better treat high-grade chondrosarcoma.

Is the Number of National Database Research Studies in Musculoskeletal Sarcoma Increasing, and Are These Studies Reliable?

BACKGROUND

Large national databases have become a common source of information on patterns of cancer care in the United States, particularly for low-incidence diseases such as sarcoma. Although aggregating information from many hospitals can achieve statistical power, this may come at a cost when complex variables must be abstracted from the medical record. There is a current lack of understanding of the frequency of use of the Surveillance, Epidemiology, and End Results (SEER) database and the National Cancer Database (NCDB) over the last two decades in musculoskeletal sarcoma research and whether their use tends to produce papers with conflicting findings.

QUESTIONS/PURPOSES

(1) Is the number of published studies using the SEER and NCDB databases in musculoskeletal sarcoma research increasing over time? (2) What are the author, journal, and content characteristics of these studies? (3) Do studies using the SEER and the NCDB databases for similar diagnoses and study questions report concordant or discordant key findings? (4) Are the administrative data reported by our institution to the SEER and the NCDB databases concordant with the data in our longitudinally maintained, physician-run orthopaedic oncology dataset?

METHODS

To answer our first three questions, PubMed was searched from 2001 through 2020 for all studies using the SEER or the NCDB databases to evaluate sarcoma. Studies were excluded from the review if they did not use these databases or studied anatomic locations other than the extremities, nonretroperitoneal pelvis, trunk, chest wall, or spine. To answer our first question, the number of SEER and NCDB studies were counted by year. The publication rate over the 20-year span was assessed with simple linear regression modeling. The difference in the mean number of studies between 5-year intervals (2001-2005, 2006-2010, 2011-2015, 2016-2020) was also assessed with Student t-tests. To answer our second question, we recorded and summarized descriptive data regarding author, journal, and content for these studies. To answer our third question, we grouped all studies by diagnosis, and then identified studies that shared the same diagnosis and a similar major study question with at least one other study. We then categorized study questions (and their associated studies) as having concordant findings, discordant findings, or mixed findings. Proportions of studies with concordant, discordant, or mixed findings were compared. To answer our fourth question, a coding audit was performed assessing the concordance of nationally reported administrative data from our institution with data from our longitudinally maintained, physician-run orthopaedic oncology dataset in a series of patients during the past 3 years. Our orthopaedic oncology dataset is maintained on a weekly basis by the senior author who manually records data directly from the medical record and sarcoma tumor board consensus notes; this dataset served as the gold standard for data comparison. We compared date of birth, surgery date, margin status, tumor size, clinical stage, and adjuvant treatment.

RESULTS

The number of musculoskeletal sarcoma studies using the SEER and the NCDB databases has steadily increased over time in a linear regression model (β = 2.51; p < 0.001). The mean number of studies per year more than tripled during 2016-2020 compared with 2011-2015 (39 versus 13 studies; mean difference 26 ± 11; p = 0.03). Of the 299 studies in total, 56% (168 of 299) have been published since 2018. Nineteen institutions published more than five studies, and the most studies from one institution was 13. Orthopaedic surgeons authored 35% (104 of 299) of studies, and medical oncology journals published 44% (130 of 299). Of the 94 studies (31% of total [94 of 299]) that shared a major study question with at least one other study, 35% (33 of 94) reported discordant key findings, 29% (27 of 94) reported mixed key findings, and 44% (41 of 94) reported concordant key findings. Both concordant and discordant groups included papers on prognostic factors, demographic factors, and treatment strategies. When we compared nationally reported administrative data from our institution with our orthopaedic oncology dataset, we found clinically important discrepancies in adjuvant treatment (19% [15 of 77]), tumor size (21% [16 of 77]), surgery date (23% [18 of 77]), surgical margins (38% [29 of 77]), and clinical stage (77% [59 of 77]).

CONCLUSION

Appropriate use of databases in musculoskeletal cancer research is essential to promote clear interpretation of findings, as almost two-thirds of studies we evaluated that asked similar study questions produced discordant or mixed key findings. Readers should be mindful of the differences in what each database seeks to convey because asking the same questions of different databases may result in different answers depending on what information each database captures. Likewise, differences in how studies determine which patients to include or exclude, how they handle missing data, and what they choose to emphasize may result in different messages getting drawn from large-database studies. Still, given the rarity and heterogeneity of sarcomas, these databases remain particularly useful in musculoskeletal cancer research for nationwide incidence estimations, risk factor/prognostic factor assessment, patient demographic and hospital-level variable assessment, patterns of care over time, and hypothesis generation for future prospective studies.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Proof of Concept of the Radiosensitizing Effect of Gadolinium Oxide Nanoparticles in Cell Spheroids and a Tumor-Implanted Murine Model of Chondrosarcoma

Purpose

Chondrosarcomas (CHSs), which represent 20% of primary bone tumors in adults, are mostly resistant to radio- and chemotherapy. It is therefore essential that new therapeutic approaches, targeted to the tumour, be developed to improve the prognosis of patients. The effectiveness, as a radiosensitizing agent, of gadolinium oxide nanoparticles (GdoNP, AGuIX^®) nanoparticles in CHS was evaluated in vitro, in spheroid CHS models allowing to reproduce cell-cell extracellular matrix interactions, and, in vivo, in a nude mouse model with heterotopic tumour xenograft.

Methods

Spheroids from SW1353 and HEMC-SS cells were characterized by confocal microscopy with or without GdoNP treatment. Real-time microscopy enabled quantification of cell viability, cell migration and invasion. In vivo, the efficacy of the association of GdoNP combined with a single (4Gy) or fractionated (4x1Gy) irradiation was evaluated in HEMC-SS tumor-bearing mice by monitoring tumor growth, mouse survival and gene expression profile.

Results

The expression of proteoglycans in the extra-cellular matrix (ECM) of spheroids demonstrated the relevance of the 3-D model. The combination of GdoNP with single or fractionated irradiation increased the lethal effects of irradiation on 2-D- and 3-D-cultured cells. In vivo, a single or a fractionated dose of 4 Gy associated with IT or IV injection of GdoNP decreased tumor growth significantly. Only IT injection increased mice survival. Unexpectedly, the radiosensitizing effect of GdoNP was associated, in vitro, with a significant decrease in invasion-migration capacities and, in vivo, with the decreased expression of PTX3, a protein involved in the epithelial-to-mesenchymal transition process, suggesting a potential impact of GdoNP on metastasis formation.

Conclusion

These results provide the first proof of concept of the radiosensitizing effect of GdoNP in CHSs and opened the way for a multicentre, randomized Phase 2 trial evaluating the association of GdoNP with radiotherapy for the therapeutic management of patients with symptomatic inoperable musculoskeletal tumor lesions.

Chondrosarcoma patient characteristics, management, and outcomes based on over 5,000 cases from the National Cancer Database (NCDB)

INTRODUCTION

Chondrosarcoma, although relatively uncommon, represents a significant percentage of primary osseous tumors. Nonetheless, there are few large-cohort, longitudinal studies of long-term survival and treatment outcomes of chondrosarcoma patients and none using the National Cancer Database (NCDB).

METHODS

Chondrosarcoma patients were identified from the 2004-2015 NCDB datasets and divided on three primary tumor sites: appendicular, axial, and other. Demographic, treatment, and long-term survival data were determined for each group. Multivariate Cox analysis and Kaplan-Meier survival curves were generated to assess long-term survival over time for each.

RESULTS

In total, 5,329 chondrosarcoma patients were identified, of which 2,686 were appendicular and 1,616 were axial. Survival was higher among the appendicular cohort than axial at 1-year, 5-year, and 10-year (89.52%, 75.76%, and 65.24%, respectively). Multivariate Cox analysis identified patients in the appendicular cohort to have significantly greater likelihood of death with increasing age category, distant metastases at presentation, and male sex (p<0.001 for each). Best outcomes for seen for those undergoing surgical treatment (p<0.001). Patients in the axial cohort were with increased likelihood of death with increasing age category and distant metastases (p<0.001), while surgical treatment with or without radiation were associated with a significant decrease (p<0.001). Kaplan-Meier survival analysis showed worst survival for the axial cohort (p<0.001) and patients with distant metastases at presentation (p<0.001). Survival was not significantly different between older (2004-2007) and more recent years (2012-2016) (p = 0.742).

CONCLUSIONS

For both appendicular and axial chondrosarcomas, surgical treatment remains the mainstay of treatment due to its continued superiority for the long-term survival of patients, although advancements in survival over the last decade have been insignificant. Presence of distant metastases and axial involvement are significant, poor prognostic factors perhaps because of difficulty in surgical excision or extent of disease.

Surgical Treatment of Bone Sarcoma

Bone sarcomas are rare primary malignant mesenchymal bone tumors. The three main entities are osteosarcoma, chondrosarcoma, and Ewing sarcoma. While prognosis has improved for affected patients over the past decades, bone sarcomas are still critical conditions that require an interdisciplinary diagnostic and therapeutic approach. While radiotherapy plays a role especially in Ewing sarcoma and chemotherapy in Ewing sarcoma and osteosarcoma, surgery remains the main pillar of treatment in all three entities. After complete tumor resection, the created bone defects need to be reconstructed. Possible strategies are implantation of allografts or autografts including vascularized bone grafts (e.g., of the fibula). Around the knee joint, rotationplasty can be performed or, as an alternative, the implantation of (expandable) megaprostheses can be performed. Challenges still associated with the implantation of foreign materials are aseptic loosening and infection. Future improvements may come with advances in 3D printing of individualized resection blades/implants, thus also securing safe tumor resection margins while at the same time shortening the required surgical time. Faster osseointegration and lower infection rates may possibly be achieved through more elaborate implant surface structures.

Identifying Modifiable and Non-modifiable Risk Factors of Readmission and Short-Term Mortality in Chondrosarcoma: A National Cancer Database Study

BACKGROUND

Limited data are available to inform the risk of readmission and short-term mortality in musculoskeletal oncology. The goal of this study was to identify factors independently associated with 30-day readmission and 90-day mortality following surgical resection of chondrosarcoma.

METHODS

We retrospectively reviewed 6653 patients following surgical resection of primary chondrosarcoma in the National Cancer Database (2004-2017). Both demographic and clinicopathologic variables were assessed for correlation with readmission and short-term mortality utilizing univariate and multivariate logistic regression modeling.

RESULTS

Of 220 readmissions (3.26%), risk factors independently associated with an increased risk of unplanned 30-day readmission included Charlson-Deyo Comorbidity Index (CDCC) (odds ratio [OR] 1.31; p = 0.027), increasing American Joint Committee on Cancer (AJCC) stage (OR 1.31; p = 0.004), undergoing major amputation (OR 2.38; p = 0.001), and axial skeletal location (OR 1.51; p = 0.028). A total of 137 patients died within 90 days of surgery (2.25%). Risk factors associated with increased mortality included the CDCC (OR 1.60; p = 0.001), increasing age (OR 1.06; p < 0.001), having Medicaid insurance status (OR 3.453; p = 0.005), living in a zip code with a higher educational attainment (OR 1.59; p = 0.003), increasing AJCC stage (OR 2.32; p < 0.001), longer postoperative length of stay (OR 1.015; p = 0.033), and positive surgical margins (OR 2.75; p = 0.001). Although a majority of the cohort did not receive radiation therapy (88.8%), receiving radiotherapy (OR 0.132; p = 0.010) was associated with a decreased risk of short-term mortality.

CONCLUSIONS

Several tumor, treatment, and patient factors can help inform the risk of readmission and short-term mortality in patients with surgically treated chondrosarcoma.

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.

Conventional Cartilaginous Tumors: Evaluation and Treatment

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Enchondromas are benign cartilaginous lesions that rarely require surgical intervention.

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Atypical cartilaginous tumors (ACTs), also referred to as grade-1 chondrosarcomas, may be managed without any intervention or with extended intralesional curettage and bone-void filling.

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High-grade chondrosarcomas, or grade-2 and 3 chondrosarcomas, should be managed aggressively with wide resection.

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Chemotherapy and radiation do not currently play a role in the treatment of chondrosarcomas.

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Differentiating an enchondroma from an ACT and an ACT from a high-grade chondrosarcoma can be difficult and requires clinical experience, radiographic and advanced imaging, and possibly a biopsy. Ultimately, a multidisciplinary team that includes a musculoskeletal oncologist, a radiologist, and a pathologist is needed to make the most appropriate diagnosis and treatment plan for each patient.

Selection of Effective Therapies Using Three-Dimensional in vitro Modeling of Chondrosarcoma

Purpose: Chondrosarcomas are a group of cartilaginous malignant neoplasms characterized by the deposition of chondrogenic extracellular matrix. Surgical resection is currently the only curative treatment option, due to their high resistance to conventional chemotherapy and radiotherapy. Novel therapeutic treatment options may improve outcome. Predominantly used cell line monolayer in vitro models lack in vivo complexity, such as the presence of extracellular matrix, and differing oxygen access. Hence, we aimed to improve pre-clinical chondrosarcoma research by developing an alginate-based 3D cell culture model.

Method: An alginate scaffold was applied to generate spheroids of three chondrosarcoma cell lines (CH2879, JJ012, SW1353). Morphological, histological and immunohistochemical assessment of the spheroids were used to characterize the chondrosarcoma model. Presto blue assay, morphological and immunohistochemical assessment were applied to assess spheroid response to a panel of chemotherapeutics and targeted therapies, which was compared to conventional 2D monolayer models. Synergistic effect of doxorubicin and ABT-737 (Bcl-2 inhibitor) was compared between monolayer and spheroid models using excess over Bliss. A 3D colony formation assay was developed for assessment of radiotherapy response.

Results: Chondrosarcoma spheroids produced chondrogenic matrix and remained proliferative after 2 weeks of culture. When treated with chemotherapeutics, the spheroids were more resistant than their monolayer counterparts, in line with animal models and clinical data. Moreover, for sapanisertib (mTOR inhibitor) treatment, a recovery in chondrosarcoma growth, previously observed in mice models, was also observed using long-term treatment. Morphological assessment was useful in the case of YM-155 (survivin inhibitor) treatment where a fraction of the spheroids underwent cell death, however a large fraction remained proliferative and unaffected. Synergy was less pronounced in 3D compared to 2D. A 3D clonogenic assay confirmed increased resistance to radiotherapy in 3D chondrosarcoma spheroids.

Conclusion: We demonstrate that the chondrosarcoma alginate spheroid model is more representative of chondrosarcoma in vivo and should be used instead of the monolayer model for therapy testing. Improved selection at in vitro stage of therapeutic testing will increase the amount of information available for experimental design of in vivo animal testing and later, clinical stages. This can potentially lead to increased likelihood of approval and success at clinical trials.

Insulin-Like Growth Factor 1 (IGF1) Pathway Member Polymorphisms Are Associated with Risk and Prognosis of Chondrosarcoma

Background

The insulin-like growth factor 1 (IGF1) pathway is deeply involved in cell proliferation, including tumorigenesis. Aberrant genetic alterations of IGF1 pathway members were revealed in certain malignancies, including chondrosarcoma (CHS). We proposed that genetic polymorphisms in IGF1 pathways might be associated with susceptibility to tumorigenesis and prognosis of CHS in Chinese populations.

Material/Methods

We recruited 112 pathologically diagnosed CHS cases and 104 cancer-free controls in this study. There were 5 single-nucleotide polymorphisms of IGF1 pathway members (IGF1R rs2016347, IGF1 rs1520220, IGF1 rs2946834, IGF3BP3 rs2270628, and IGF2 rs4320932) genotyped that subsequently underwent bioinformatic analyses. DNA from validated CHS cases was extracted from frozen blood samples preserved in liquid nitrogen, while DNA from tumor-free controls was extracted from fresh blood. SNP genotyping was conducted by PCR.

Results

The variant T allele of IGF1R (rs2016347) is potentially correlated with poor outcome in patients with conventional CHS. The GT and TT genotypes of IGF1R rs2016347 predicted statistically significant higher risk of tumor metastasis and higher histological grade of CHS.

Conclusions

We hypothesized that IGF1 member polymorphisms are associated with chondrosarcoma. We found that genetic polymorphisms in IGF1 pathway members are associated with elevated risk and poor prognosis of conventional CHS patients in Chinese populations. IGF1R rs2016347 polymorphisms were associated with the risk of lung metastasis of CHS. The IGF1 pathway members do not appear to be involved in the tumorigenesis of CHS.

Postoperative Radiation Therapy in Patients with Extracranial Chondrosarcoma: A Joint Study of the French Sarcoma Group and Rare Cancer Network

PURPOSE

Postoperative radiation therapy (poRT) of intracranial/skull base chondrosarcomas (CHSs) is standard treatment. However, consensus is lacking for poRT in extracranial CHS (eCHS) owing to their easier resectability and intrinsic radioresistance. We assessed the practice and efficacy of poRT in eCHS.

METHODS AND MATERIALS

This multicentric retrospective study of the French Sarcoma Group/Rare Cancer Network included patients with eCHS who were operated on between 1985 and 2015. Inverse propensity score weighting (IPTW) was used to minimize poRT allocation biases.

RESULTS

Of 182 patients, 60.4% had bone and 39.6% had soft-tissue eCHS. eCHS were of conventional (31.9%), myxoid (28.6%; 41 extraskeletal, 11 skeletal), mesenchymal (9.9%), or other subtypes. En-bloc surgery with complete resection was performed in 52.6% and poRT in 36.8% of patients (median dose, 54 Gy). Irradiated patients had unfavorable initial characteristics, with higher grade and incomplete resection. Median follow-up time was 61 months. Five-year incidence of local relapse was 10% with poRT versus 21.6% without (P = .050). Using the IPTW method, poRT reduced the local relapse risk (hazard ratio, 0.27; 95% confidence interval, 0.14-0.52; P < .001). Five-year disease-free survival (DFS) was 71.8% with poRT and 64.2% without (P = .680). Using the IPTW method, poRT improved DFS (hazard ratio, 0.51; 95% confidence interval, 0.30-0.85; P = .010). The benefit of poRT on local relapse and DFS was confirmed after exclusion of the extraskeletal subtype. There was no difference in overall survival. Prognostic factors of poorer DFS in multivariate analysis were deeper location, higher grade, incomplete resection, and no poRT.

CONCLUSIONS

poRT should be offered in patients with eCHS and high-grade or incomplete resection, regardless of the histologic subtype.