Classification of Chondrosarcoma: From Characteristic to Challenging Imaging Findings

Rare malignant primary spinal chondrosarcoma: A case report

Chondrosarcomas are one of malignant tumors in which cartilaginous matrix is produced. It is divided into 2 groups including primary or secondary. Primary chondrosarcomas are the third most common primary malignant tumors of the bone. Chondrosarcoma represents 20%-27% of all primary malignant bone tumors. Primary spinal chondrosarcoma is exceedingly rare among spinal tumors. A 36-year-old man presented to hospital with the swelling on the back accompanied with pain. Swelling and pain have been felt for approximately 3 years. The symptoms gradually worsened. On thoracolumbal X-ray a lytic sclerotic expansile lesion on the right posterior aspect of thoracal T5-T6. MRI showed the mass infiltrated intradural and intramedullary, reaching up to the level of vertebrae T4-T5. This infiltration resulted in stenosis of the spinal canal, obliterating the ligamentum flavum, supraspinous ligament, and interspinous ligament. Chondrosarcomas are uncommon malignant bone tumours that form cartilage; they rarely involve the spine, while most of them occur in young men. The thoracic spine is most commonly involved, but there is usually a long history of pain and possible neurological symptoms. Imaging techniques, such as conventional examination, CT, and MRI, are very important for diagnosis and classification and show typical bone destruction with matrix mineralization. Imaging revealed a lytic sclerotic lesion at the T5-T6 level. CT scans performed subsequently showed an expansile mass with a typical ``rings and arcs'' appearance of chondrosarcomas. MRI further delineated the extent of the mass and the surrounding tissue infiltration, and confirmation of low-grade chondrosarcoma, grade I was based on histological examination. The most effective treatment has been en bloc resection, and high-dose adjuvant radiotherapy might improve local control and survival rates. Recommended follow-ups are for the purpose of monitoring recurrence. Primary spinal chondrosarcoma is a rare malignant tumor that predominantly affects adolescents. The standard treatment typically involves surgical intervention, often supplemented with adjuvant radiotherapy. Many patients experience considerable improvements in neurological function following treatment. Long-term monitoring and follow-up are crucial for ensuring the best possible outcomes for individuals with primary spinal chondrosarcoma.

MR Imaging of Tumors and Tumor-Like Conditions of the Hip

The hip joint is home to a diverse range of neoplasms, as well as many pseudo lesions, including post-traumatic, infectious, and degenerative processes. Through careful evaluation of the clinical context, location, and imaging features, these entities can be distinguished, enabling accurate and efficient diagnosis. While not exhaustive, this article reviews a selection of benign, malignant, and non-neoplastic lesions affecting the hip bones, cartilage, and soft tissues, focusing on their notable imaging and pathologic features.

Optimal Magnetic Resonance Sequence for Assessment of Central Cartilage Tumor Scalloping

Background  Magnetic resonance imaging (MRI) is key in evaluating central cartilage tumors. The BACTIP (Birmingham Atypical Cartilaginous Tumour Imaging Protocol) protocol assesses central cartilage tumor risk based on the tumor size and degree of endosteal scalloping on MRI. It provides a management protocol for assessment, follow-up, or referral of central cartilage tumors. Objectives  Our study compared four MRI sequences: T1-weighted (T1-w), fluid sensitive (Short Tau Inversion Recovery (STIR)- weighted, STIR-w), and grayscale inversions (T1-w GSI and short tau inversion recovery [STIR] GSI) to see how reliably endosteal scalloping was detected. Materials and Methods  Two senior consultant musculoskeletal radiologists with experience reviewed randomly selected 60 representative central cartilage tumor cases with varying degree of endosteal scalloping to reflect a spectrum of BACTIP pathologies. The endosteal scalloping was graded as per the definition of BACTIP A, B, and C. They agreed on a consensus BACTIP grade for each of the 240 key images (60 cases × 4 sequences), which was considered the final "consensus" BACTIP grade. These 240 images were then randomized into a test set and given to two fellowship-trained consultant musculoskeletal radiologists for analysis. They assigned a BACTIP grade to each of the 240 selected images while being blinded to the final "consensus" BACTIP grade. The training set was further subdivided into three groups based on the MR image quality (good quality, average quality, and poor quality) to ascertain if the quality of the acquired images influenced intraobserver and interobserver agreements on the BACTIP grading. The two observers were blinded to the grade assigned to the image quality. Results  Linearly weighted kappa analysis was performed to measure the agreement between the BACTIP grading answers by two observers and the "consensus" BACTIP grading answers, as well as the BACTIP grading agreement between the two observers themselves. The analysis revealed that T1-w and STIR-w sequences demonstrated more consistent and higher agreement across different image qualities. However, the T1-w GSI and STIR-w GSI sequences exhibited lower agreement, particularly for poor-quality images. T1-w imaging demonstrated substantial agreement between BACTIP gradings for poor-quality images, suggesting potential resilience of T1-w sequence in challenging imaging conditions. Conclusion  T1-w imaging is the best sequence for BACTIP grading of endosteal scalloping, followed by fluid-sensitive STIR sequences.

Transcriptomic data integration and analysis revealing potential mechanisms of doxorubicin resistance in chondrosarcoma cells

Chondrosarcoma is a type of bone cancer that originates from cartilage cells. In clinical practice, surgical resection is the primary treatment for chondrosarcoma, but chemotherapy becomes essential for patients with metastasis or tumors in surgically inaccessible sites. However, drug resistance often leads to treatment failure. Tumor microenvironment proteins modulate intercellular communication, contributing to drug resistance. Doxorubicin (Dox) is a common chemotherapeutic agent. The present study aimed to establish Dox-resistant chondrosarcoma cells and compare their secretome with parental cells using antibody arrays. Results showed significantly heightened secretion of hepatocyte growth factor (HGF). Knockdown of both HGF and its receptor MET increased Dox sensitivity in chondrosarcoma cells. Treatment of chondrosarcoma cells with conditioned media (CM) from cells secreting high levels of HGF resulted in MET activation. Additionally, the expression levels of HGF and MET were significantly elevated in chondrosarcoma tissues compared to normal cartilage tissues, as confirmed by analysis of GEO database. RNA sequencing and Gene Set Enrichment Analysis (GSEA) elucidated the mechanism involving HGF. Additionally, genes with log fold change > 1 underwent bioinformatics analysis using the ShinyGO web server. The results from both GSEA and ShinyGO analyses corroborate each other, indicating the significance of HGF in cellular signal transduction, regulation of cell motility, developmental processes, immune-inflammatory responses, and functions related to blood and neural systems. In summary, highly secreted HGF can activate signaling pathways through its receptor MET, particularly Ras and Akt activation, enhancing drug resistance in chondrosarcoma cells. The present study may guide the development of novel therapeutic strategies targeting HGF, ultimately improving treatment outcomes and prognosis for malignant chondrosarcoma patients.

Prognostic Impact of a Histologic Grading Scheme in Dogs Diagnosed With Rib Chondrosarcoma

Data regarding the outcome of canine rib chondrosarcoma is sparse and varied. While grade of tumour is associated with outcome for canine appendicular chondrosarcoma, the association of grade with outcome for canine rib chondrosarcoma is unclear. This study aimed to correlate the grade of canine rib chondrosarcoma with median survival time. Retrospectively, cases of primary rib chondrosarcoma were identified, and tumours were graded based on a 3-tier adapted human grading scheme. Twenty-two patients were included in the survival analysis. The median survival time was 1427 days (range: 27-3354 days). This was not significantly different for patients with grade I versus II versus III (p = 0.82), grade I-II versus III (p = 0.34), or grade I versus II-III (p = 0.49). No variables assessed including age, weight, tumour location (cranial vs. caudal thorax; left vs. right hemithorax), tumour location on rib (proximal, middle, and distal), radiographic appearance (lytic, proliferative, or mixed), elevated serum alkaline phosphatase activity, grade, grade specific histologic features (matrix production, architecture, pleomorphism, cellularity, necrosis, and total score), adjunct therapy post-surgical excision, development of metastatic disease post-surgery, or local recurrence post-surgery were found to impact the risk of death due to chondrosarcoma. In this limited group of patients, the grading scheme reported here, and the other variables assessed did not appear to offer additional prognostic information. However, this data must be interpreted considering the small sample size and thus low statistical power. Additional studies are needed to determine the true impact of grade on outcome for canine rib chondrosarcomas.

Hereditary multiple exostoses with a giant osteochondroma degenerated into chondrosarcoma

We present a case of hereditary multiple exostoses with malignant transformation to chondrosarcoma in a woman complaining of enlargement and pain in the right thigh. Hereditary multiple exostoses is a rare genetic disorder characterized by multiple osteochondromas. Malignant transformation to chondrosarcoma of a pre-existing osteochondroma is a possible significant manifestation of this hereditary syndrome. Imaging modalities such as X-ray, Ultrasound, and computed tomography play a crucial role in the diagnosis and management of these patients, as described in this case.

Nasal clear cell chondrosarcoma in a dog

An intranasal tumour was diagnosed in a 5-year-old male neutered crossbreed dog following a 6-8 week history of intermittent epistaxis and nasal discharge. Computed tomography identified a mass in the right nasal cavity. Histologically, the mass was composed of sheets and indistinct clusters of predominantly clear or vacuolated round to polygonal cells; periodic acid-Schiff staining revealed glycogen granules within some tumour cells. Immunohistochemical labelling revealed that the tumour cells were immunopositive for vimentin and S100 and negative for pancytokeratin, Melan-A and PNL2, supporting a diagnosis of a clear cell variant of chondrosarcoma (CCC). Although the dog was treated with meloxicam, the owners opted for euthanasia 9 days after presentation. Considering that there is only one other reported case of a suspected CCC in a dog, also in the nasal cavity, this could represent a species-specific predilection site of this rare canine neoplasm.

The stimulation of exosome generation by visfatin polarizes M2 macrophages and enhances the motility of chondrosarcoma

Chondrosarcoma is a malignant bone tumor that arises from abnormalities in cartilaginous tissue and is associated with lung metastases. Extracellular vesicles called exosomes are primarily used as mediators of intercellular signal transmission to control tumor metastasis. Visfatin is an adipokine reported to enhance tumor metastasis, but its relationship with exosome generation in chondrosarcoma motility remains undetermined. Our results found that overexpressing visfatin augments the production of exosomes from chondrosarcoma cells. Visfatin-treated chondrosarcoma exosomes educate macrophage polarization towards the M2 but not M1 phenotype. Interestingly, M2 macrophages polarized by exosomes return to chondrosarcoma cells to facilitate cell motility. According to these findings, chondrosarcoma cells emit more exosomes when treated with visfatin. The stimulation of exosome generation by visfatin polarizes M2 macrophages and enhances the motility of chondrosarcoma.

Unusual soft tissue metastases in a patient with chondrosarcoma: a case report

Chondrosarcoma (CS) is the second most frequent primary malignant bone tumour, characterized by production of non-osteoid cartilage matrix. Up to more than 30% of patients with CS present distant metastases, and the lungs represent the preferred site. Hence, CS soft tissue metastases and superficial cutaneous lesions are extremely rare. We report the case of a female who developed unusual multiple soft tissue CS metastases. This patient underwent left hindquarter amputation for recurrent grade 3 chondrosarcoma of the femoral neck with extension to the pelvis approximately 4 years after internal fixation with an intramedullary nail for pathological fracture of left proximal femur and subsequent total proximal femoral endoprosthetic replacement for grade 1-2 chondrosarcoma. In the following years, she underwent metastasectomy for several grade 2 pulmonary metastatic chondrosarcomas. More than 14 years after the amputation, she presented with multiple unusual superficial cutaneous lesions, and a whole-body magnetic resonance imaging demonstrated multiple soft tissue foci of metastatic disease. The histology of multiple soft tissue lesions excised confirmed metastatic chondrosarcoma. Then, she underwent marginal excision of further multifocal soft tissue metastatic high-grade chondrosarcoma. Unlike the poor survival from the onset of these metastases in the other cases reported in the literature, our patient is still alive 2 years after the first multiple soft tissue excision of metastatic chondrosarcoma, and approximately 20 years after the diagnosis of chondrosarcoma. Soft tissue CS metastases are a rare entity with few cases described in literature. This study aims to make the reader aware of this lesser-known CS manifestation.

Diagnosis of chondrosarcoma in a noninvasive way using volatile organic compounds in exhaled breath: a pilot study

Aim: Aim of this explorative pilot study was to evaluate the capability of an electronic nose (aeoNose, the eNose Company) to classify healthy individuals and patients with chondrosarcoma, based on their volatile organic compound profiles in exhaled breath.Materials & methods: Fifty-seven patients (25 healthy controls, 24 chondrosarcoma and 8 different benign lesions) were included in the study from 2018 to 2023. An artificial neural network was used as classifier.Results: The developed model had a sensitivity of 75%, and a specificity of 65% with an AUC of 0.66.Conclusion: Results show that there is not enough evidence to include the aeoNose as diagnostic biomarker for chondrosarcoma in daily practice. However, the aeoNose might play an additional role alongside MRI, in questionable chondrosarcoma cases.

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.

Quantitative Bone SPECT/CT of Central Cartilaginous Bone Tumors: Relationship between SUVmax and Radiodensity in Hounsfield Unit

(1) Background: it is challenging to determine the accurate grades of cartilaginous bone tumors. Using bone single photon emission computed tomography (SPECT)/computed tomography (CT), maximum standardized uptake value (SUVmax) was found to be significantly associated with different grades of cartilaginous bone tumor. The inquiry focused on the effect of the tumor matrix on SUVmax. (2) Methods: a total of 65 patients from 2017 to 2022 with central cartilaginous bone tumors, including enchondromas and low-to-intermediate grade chondrosarcomas, who had undergone bone SPECT/CT were retrospectively enrolled. The SUVmax was recorded and any aggressive CT findings of cartilaginous bone tumor and Hounsfield units (HU) of the chondroid matrix as mean, minimum, maximum, and standard deviation (SD) were reviewed on CT scans. Pearson's correlation analysis was performed to determine the relationship between CT features and SUVmax. Subgroup analysis was also performed between the benign group (enchondroma) and the malignant group (grade 1 and 2 chondrosarcoma) for comparison of HU values and SUVmax. (3) Results: a significant negative correlation between SUVmax and HU measurements, including HUmax, HUmean, and HUSD, was found. The subgroup analysis showed significantly higher SUVmax in the malignant group, with more frequent CT aggressive features, and significantly lower HUSD in the malignant group than in the benign group. (4) Conclusions: it was observed that higher SUVmax and lower HUSD were associated with a higher probability of having a low-to-intermediate chondrosarcoma with aggressive features and a less calcified tumor matrix.

Visfatin Facilitates VEGF-D-Induced Lymphangiogenesis through Activating HIF-1α and Suppressing miR-2277-3p in Human Chondrosarcoma

Chondrosarcoma is a malignant bone tumor that arises from abnormalities in cartilaginous tissue and is associated with lung metastases. Lymphangiogenesis plays an essential role in cancer metastasis. Visfatin is an adipokine reported to enhance tumor metastasis, but its relationship with VEGF-D generation and lymphangiogenesis in chondrosarcoma remains undetermined. Our results from clinical samples reveal that VEGF-D levels are markedly higher in chondrosarcoma patients than in normal individuals. Visfatin stimulation promotes VEGF-D-dependent lymphatic endothelial cell lymphangiogenesis. We also found that visfatin induces VEGF-D production by activating HIF-1α and reducing miR-2277-3p generation through the Raf/MEK/ERK signaling cascade. Importantly, visfatin controls chondrosarcoma-related lymphangiogenesis in vivo. Therefore, visfatin is a promising target in the treatment of chondrosarcoma lymphangiogenesis.

CT and MR imaging findings of head and neck chondrosarcoma

OBJECTIVES

This study investigated the imaging features of head and neck chondrosarcoma (HNCS) according to its origin and pathologic subtype.

METHODS

Patients who were pathologically diagnosed with HNCS between January 2000 and April 2022 were retrospectively reviewed. Lesions were classified based on their origin and pathologic subtype. The size and margin were evaluated on the image. Internal calcification and the effects on adjacent bone were assessed using computed tomography (CT) images, while signal intensity and contrast enhancement patterns were analyzed using magnetic resonance (MR) imaging.

RESULTS

Thirteen HNCSs were included in this study: 8 bone tumors (61.5%) and 5 soft tissue tumors (38.5%). The bone tumors were pathologically diagnosed as conventional (n = 5) and mesenchymal type (n = 3). Soft tissue tumors were defined as myxoid type. The main symptoms were swelling (90.9%) and pain (72.7%). The lesions measured 4.5 cm on average. The margins showed benign and well-defined except for the mesenchymal type. On CT, most bone tumors (75%) showed internal calcification with remodeling or destruction of the adjacent bone. No soft tissue tumors, except one case, showed internal calcification or destruction of the adjacent bone. MR imaging features were non-specific (T2 high signal intensity and contrast enhancement).

CONCLUSIONS

HCNS showed various imaging findings according to their origin and pathologic subtype. HNCS should be differentiated if a bone tumor shows internal calcification and affects the adjacent bone. When diagnosing slow-growing soft tissue tumors, even if low possibility, HNCS should be considered.

Histologic Heterogeneity of Chondrosarcoma Reflected on Bone SPECT/CT

ABSTRACT

Chondrosarcomas are a heterogeneous group of cartilage-forming tumors. The tumor is graded on areas demonstrating the highest grade. A 71-year-old man underwent bone SPECT/CT to investigate a tumorous lesion on his right femur. Correlating with the pathological findings, the high-grade area showed higher uptake in bone SPECT/CT. This case suggests that bone SPECT/CT could aid in selecting an optimal biopsy site for diagnosis, and determining the proper treatment of patients with suspected chondroid tumors.

Extraskeletal conventional chondrosarcoma of genitalia in a child- An unusual pathology for a rare tumor

INTRODUCTION AND IMPORTANCE

Chondrosarcoma is a rare malignant tumor considered as the second common sarcoma of bone following osteosarcoma. Less than 5 % of chondrosarcomas occur in children. Conventional chondrosarcoma is the most common type observed as skeletal tumors. Extraskeletal chondrosarcomas account for about 1 % of chondrosarcomas. They are almost always of myxoid or mesenchymal subtypes.

CASE PRESENTATION

A 4-year-old girl was referred with pain and palpable mass in the labia majora since 2 years of age for which she had undergone twice biopsies, reported as soft tissue enchondroma. At this time, complete excision of the lesion with negative margins was carried out. The pathology was in favor of extraskeletal chondrosarcoma of conventional type without any evidence of bone involvement.

CLINICAL DISCUSSION

Our case was a very young child with extraskeletal conventional chondrosarcoma, not reported yet in the literature. The vast majority of extraskeletal myxoid chondrosarcomas arise in the soft tissues of the extremities. The lesion in this case was located within the subcutaneous tissue of the labia majora; however, the tumor was not compatible with myxoid chondrosarcoma. Mesenchymal chondrosarcoma is another type of extraskeletal chondrosarcoma but the histopathologic patterns observed in our patient were not compatible even with the mesenchymal chondrosarcoma.

CONCLUSION

We present a unique case of extraskeletal chondrosarcoma in a child with conventional subtype which has not been reported in the literature. In addition, the lesion was assumed to arise from a previous soft tissue enchondroma of the labia majora since infancy which makes the case distinctive.

Chondrosarcoma of the Femur: Is Local Recurrence Influenced by the Presence of an Extraosseous Component?

BACKGROUND

Chondrosarcoma (CS) is the second most common surgically treated primary malignancy of the bone. The current study explored the effect of the margin and extraosseous tumor component in CS in the femur on local recurrence (LR), LR-free survival (LRFS), and disease-specific survival (DSS).

METHODS

Among 202 patients, 115 were in the proximal extremity of the femur, 4 in the corpus of the femur, and 83 in the distal extremity of femur; 105 patients had an extraosseous tumor component.

RESULTS

In the Kaplan-Meier analysis, factors significant for decreased LRFS were the extraosseous tumor component (p < 0.001), extraosseous tumor component arising from the superior aspect (p < 0.001), histological grade (p = 0.031), and narrow surgical margin < 3 mm (p < 0.001). Factors significantly affecting DSS were the histological grade (p < 0.001), extraosseous component (p < 0.001), LR (p < 0.001), metastases (p < 0.001), and surgical margin (p < 0.001).

CONCLUSIONS

In CS of the femur, the presence of an extraosseous tumor component has a predictive role in LRFS, and extraosseous tumor component arising from the superior aspect was significant for decreased LRFS. Wide margins were more commonly achieved when the tumor had only an intraosseous component, and the rate of LR was significantly higher in cases with an extraosseous tumor component. When the extraosseous component arose from the superior aspect of the femur, LR occurred more frequently despite achieving adequate margins.

Update of cartilaginous tumours according to the WHO classification 2020

Cartilaginous tumours are a large and heterogeneous group of neoplasms characterised by the presence of a chondroid matrix, with lobular growth and arcuate, ring-like or popcorn-like calcification patterns. MRI shows hyperintensity in T2-weighted sequences and a lobulated or septal relief in postcontrast images. In the WHO 2020 classification, chondral tumours are classified as benign, intermediate or malignant. Despite technological advances, they continue to pose a challenge for both the radiologist and the pathologist, being the main difficulty the differentiation between benign and malignant tumours, which is why they require a multidisciplinary approach. This paper describes the main changes introduced in the 2020 update, describes the imaging characteristics of the main cartilaginous tumours and provides the radiological keys to differentiate between benign and malignant tumours.

[Imaging Findings of Spinal Metastases with Differential Diagnosis: Focusing on Solitary Spinal Lesion in Older Patients]

If a solitary spinal lesion is found in an older patient, bone metastasis can be primarily considered as the diagnosis. Bone metastasis can occur anywhere, but it mostly occurs in the vertebral body and may sometimes show typical imaging findings, presenting as a single lesion. Therefore, differentiating it from other lesions that mimic bone metastases can be challenging, potentially leading to delayed diagnosis and initiation of primary cancer treatment. This review provides an overview of imaging findings and clinical guidelines for bone metastases and discusses its differences from other diseases that can occur as solitary spinal lesions in older patients.

Mesenchymal Chondrosarcoma from Diagnosis to Clinical Trials

Mesenchymal chondrosarcoma (MCS) is a rare subtype of chondrosarcoma with a poor prognosis. Although these tumors are sensitive to radiotherapy/chemotherapy, the standard treatment for localized MCS is only surgical resection, and there are no established treatment guidelines for patients with advanced and metastatic MCS. Due to the low incidence of MCS, the pathology of these tumors is still unknown, and other therapeutic options are lacking. Some studies show the potential role of the PDGF/PPI3K/AKT, PKC/RAF/MEK/ERK, and pRB pathways, and BCL2 overexpression in the pathogenesis of MCS. These findings provide an opportunity to use protein kinases and BCL2 inhibitors as potential therapy in MCS. In this review, we summarize the current knowledge about MCS diagnosis and treatment options. We show the immunological and molecular biomarkers used in the diagnosis of MCS. In addition, we discuss the known prognostic and predictive factors in MCS. Finally, we present the novel trends, including targeted therapies and ongoing clinical trials using protein kinase inhibitors and the death receptor 5 (DR5) agonist, which may be the focus of future MCS treatment studies.

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.

Development and validation of a nomogram for predicting prognosis of high-grade chondrosarcoma: A surveillance, epidemiology, and end results-based population analysis

BACKGROUND

The incidence of chondrosarcoma is increasing every year, and the treatment and prognosis of patients with high-grade chondrosarcoma are becoming more and more important. Nomogram is a tool that can quickly and easily predict the overall survival of tumor patients. Therefore, the development and validation of a nomogram to predict overall survival in patients with high-grade chondrosarcoma was desired.

METHODS

We retrospectively collected 396 patients with high-grade chondrosarcoma from the Surveillance, Epidemiology, and End Results (SEER) database from 2004 to 2015. Randomly divided into model and validation groups, the best cut-off values for age and tumor size grouping were derived by using X-tile software. Then, independent prognostic factors for high-grade chondrosarcoma were derived by SPSS.26 univariate and multivariate Cox analyses analysis in the model group, and the model was evaluated by using R software, using C-indix and ROC curves, and finally these independent prognostic factors were included in Nomogram.

RESULTS

396 patients were randomly assigned to the modelling group (n = 280) or the validation group (n = 116). Age, tissue-type, tumor size, AJCC stage, regional expansion and surgery were identified as independent prognostic factors (p < 0.05) which further combined to construct a nomogram. The C-index of internal validation for overall survival(OS) was 0.757, while the C-index of external validation for overall survival(OS) was 0.832. Both internal and external calibration curves show a good agreement between nomogram prediction and actual survival.

CONCLUSION

In this study, we established age, tumour size, AJCC stage, tissue type, surgery and tumor extension as independent prognostic factors for high-grade chondrosarcoma and constructed a nomogram to predict 3- and 5-year survival rates for high-grade chondrosarcoma.