CT radiomics-based machine learning model for differentiating between enchondroma and low-grade chondrosarcoma.

It may be difficult to distinguish between enchondroma and low-grade malignant cartilage tumors (grade 1) radiologically. This study aimed to construct machine learning models using 3D computed tomography (CT)-based radiomics analysis to differentiate low-grade chondrosarcoma from enchondroma. A total of 30 patients with enchondroma and 26 with chondrosarcoma were included in this retrospective study. Tumor volume segmentation was manually performed by 2 musculoskeletal radiologists. In total, 107 radiomic features were obtained for each patient. The intraclass correlation coefficient was used to assess interobserver reliability and estimate the absolute agreement between the 2 radiologists. Algorithm-based information gain was used as a feature reduction method, and the 5 most important features were detected. For classification, 7 machine learning models were utilized. Classification was carried out using either all features or 5 features. There was good to excellent agreement between the 2 radiologists for the 107 features of each patient. Therefore, a dataset containing 107 features was used for machine learning classification. When assessed based on area under curve (AUC) values, classification using all features revealed that naive Bayes was the best model (AUC = 0.950), while classification using 5 features revealed that random forest was the best model for differentiating chondrosarcoma from enchondroma (AUC = 0.967). In conclusion, machine learning models using CT-based radiomics analysis can be used to differentiate between low-grade chondrosarcoma and enchondroma.

Laryngeal rare benign non-epithelial tumors and sarcomas emphasizing on chondrosarcomas: A literature review and a case presentation.

Laryngeal rare tumors include benign and malignant tumors of epithelial, non-epithelial, or mesenchymal origin. Chondrosarcomas are the most common mesenchymal malignant tumors of the larynx. We performed a literature review (Pubmed/Medline; PRISMA 2020) to detect the frequency of published studies from 2021 to April 2024 regarding benign and malignant epithelial, non-epithelial, or mesenchymal rare tumors of the larynx, emphasizing laryngeal chondrosarcoma (LC) cases. Articles including cases discussed before 2021 were excluded and articles without available English translations. We included 154 articles investigating rare tumors of the larynx, the majority of them discussed non-epithelial or mesenchymal entities (75 %). Specifically, a high proportion of studies examined benign non-epithelial or mesenchymal tumors (79.5 %) or mesenchymal rare malignancies (72 %) of the larynx concerning epithelial tumors in the last three years. Sarcomas were discussed in 74 % of mesenchymal laryngeal malignancies and more than 50 % of rare laryngeal tumor studies, and LC was discussed in ∼50 % of laryngeal sarcoma studies. LC studies reported 174 cases, 21 % of them of high-grade LC (II), including a new case of LC presented here in the supraglottic (grade II), which showed intense staining for the S100 marker. Our study highlights the awareness of rare laryngeal tumors emphasizing non-epithelial benign tumors and laryngeal sarcomas, including chondrosarcomas, as pathologic entities of the larynx. Although the majority of LC included low-grade neoplasms, a markedness proportion of LC cases was evaluated as high-grade. Future research approaches, including a range of low and high-grade tumors, would reveal prognostic markers or therapeutic targets for LC and other rare laryngeal malignancies of non-epithelial or mesenchymal origin.

[Clincopathological analysis of 171 patients with osteochondroma and malignant transformation in maxillofacial bone].

PURPOSE: To investigate the clinical and pathological features of osteochondroma in maxillofacial region, and to summarize the clinicopathological features of rare osteochondroma malignant transformation in order to provide clinical guidance. METHODS: From January 2018 to September 2023, a total of 171 patients with osteochondroma were retrospectively collected in Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine. Their preoperative CT and clinicopathological features were analyzed. RESULTS: Of the 171 patients with osteochondroma in maxillofacial bone, 66%（113/171） were females and 34% were male. Their age ranged from 11-76 with an average age was 44 years old. Of the 171 cases, 95.3%（163/171）in mandible condyle, 4%(7/171) in mandible processus coronoideus, and 0.5%（1/171） in zygomatic arch. The imaging findings showed that the thickness of cartilaginous cap was less than 1 cm in 98%（159/161） cases with condyle lesions. Only 2 cases(2/171, 1.1%) had malignant transformation. One was diagnosed with secondary chondrosarcoma, another developed low-grade osteosarcoma. CONCLUSIONS: Osteochondroma in maxillofacial region mostly occurs in females, and most commonly located in condylar process, with a malignant change rate of 1.1%, which is similar to that of other parts of the body. Imaging findings have important guiding significance for the diagnosis of osteochondroma malignant change.

Novel machine-learning prediction tools for overall survival of patients with chondrosarcoma: Based on recursive partitioning analysis.

BACKGROUND: Chondrosarcoma (CHS), a bone malignancy, poses a significant challenge due to its heterogeneous nature and resistance to conventional treatments. There is a clear need for advanced prognostic instruments that can integrate multiple prognostic factors to deliver personalized survival predictions for individual patients. This study aimed to develop a novel prediction tool based on recursive partitioning analysis (RPA) to improve the estimation of overall survival for patients with CHS. METHODS: Data from the Surveillance, Epidemiology, and End Results (SEER) database were analyzed, including demographic, clinical, and treatment details of patients diagnosed between 2000 and 2018. Using C5.0 algorithm, decision trees were created to predict survival probabilities at 12, 24, 60, and 120 months. The performance of the models was assessed through confusion scatter plot, accuracy rate, receiver operator characteristic (ROC) curve, and area under ROC curve (AUC). RESULTS: The study identified tumor histology, surgery, age, visceral (brain/liver/lung) metastasis, chemotherapy, tumor grade, and sex as critical predictors. Decision trees revealed distinct patterns for survival prediction at each time point. The models showed high accuracy (82.40%-89.09% in training group, and 82.16%-88.74% in test group) and discriminatory power (AUC: 0.806-0.894 in training group, and 0.808-0.882 in test group) in both training and testing datasets. An interactive web-based shiny APP (URL: https://yangxg1209.shinyapps.io/chondrosarcoma_survival_prediction/) was developed, simplifying the survival prediction process for clinicians. CONCLUSIONS: This study successfully employed RPA to develop a user-friendly tool for personalized survival predictions in CHS. The decision tree models demonstrated robust predictive capabilities, with the interactive application facilitating clinical decision-making. Future prospective studies are recommended to validate these findings and further refine the predictive model.

Total Laryngeal Transplant in the Setting of Active Laryngeal Malignancy.

Laryngeal transplant (LT) is a promising option to restore quality of life in patients with severe laryngeal dysfunction or a laryngectomy. These patients may be tracheostomy tube dependent or gastrostomy tube dependent and may lose their ability to verbally communicate. The loss of these important functions frequently results in social isolation and a severe decrease in quality of life. Laryngeal transplant has the potential to restore all of these important laryngeal functions. Herein, we report the first known documented LT performed in the setting of laryngeal chondrosarcoma.

[Analysis of influencing factors of recurrence after en bloc spondylectomy of spinal tumors].

Objectives: To investigate the survival and tumor recurrence after en bloc spondylectomy of spinal tumor and analyze the risk factors of postoperative tumor recurrence. Methods: This is a retrospective case series study. Data of 101 patients undergoing en bloc spondylectomy of spinal tumors in the Musculoskeletal Tumor Center, Peking University People's Hospital from December 2006 to June 2022 were analyzed. There were 58 males and 43 females, aged (38.2±15.8) years (range: 10 to 79 years) at the time of surgery; the follow-up time was(44.0±36.0) months (range: 12 to 171 months).Among them, there were 25 relapsed patients, with 7 females and 18 males; aged (34.8±16.3) years (range: 12 to 66 years) at the time of surgery. The types of tumors included 5 giant cell tumors of bone, 6 osteosarcomas, 1 chordoma, 5 chondrosarcomas, 1 undifferentiated sarcoma, 1 fibrosarcoma, 2 Ewing sarcomas, 3 metastases and 1 malignant giant cell tumor of bone. Survival analysis of overall and relapsed patients were performed using the Kaplan-Meier curves. A segmented regression model was used to fit the sequence of recurrence rate changes over time since admission and identify change points for further analysis on risk factors. Univariate and multivariate Logistic regression analysis were performed to assess risk factors associated with recurrence rate; results from multivariate regression analysis were presented using a forest plot. Results: The tumor recurrence rate after en bloc spondylectomy was 24.8% (25/101).The overall median recurrence-free survival after en bloc spondylectomy was 161 months (95%CI: 92 months to NA).The median recurrence-free survival of recurrent patients was 13 months (95%CI: 12 to 27 months).Regarding the classification based on tumor malignancy, and relapse-free survival of metastatic tumors was significantly shorter (P=0.007); and among the surgical margin groups, relapse-free survival of R0 group was significantly better than the R1 and R2 groups (P<0.01). According to the segmented regression model, the tumor recurrence rate for en bloc spondylectomy showed a significant downward trend over time, with relatively higher recurrence rates before 2009 and a relatively stable trend after 2014. The results of univariate analysis showed that surgical margin and time of admission were the influencing factors of patient recurrence. The results of multivariate analysis showed that the R1 resection(OR=13.453,95%CI:2.897 to 97.941,P=0.002) and R2 resection(OR=11.379,95%CI:2.658 to 79.429,P=0.003) were independent influencing factor affecting patient recurrence. Conclusions: The overall tumor recurrence rate after en bloc spondylectomy was high. The surgical margin of tumor resection is an independent risk factor affecting tumor recurrence. Specifically, R2 and R1 resections significantly increase the risk of tumor recurrence.

Advances in the multidisciplinary surgical approach to primary spinal sarcomas: insights from a retrospective case series on outcomes and survival.

INTRODUCTION: The management of spinal sarcomas is complex, given their widespread involvement and high recurrence rates. Despite consensus on the need for a multidisciplinary approach with surgery at its core, there is a lack of definitive guidelines for clinical decision-making. This study examines a case series of primary spinal sarcomas, focusing on the surgical strategies, clinical results, and survival data to inform and guide therapeutic practices. METHODS: We conducted a retrospective analysis of patients who underwent surgical resection for primary spinal sarcomas between 2005 and 2022. The study focused on gathering data on patient demographics, surgical details, postoperative complications, overall hospital stay, and mortality within 90 days post-surgery. RESULTS: The study included 14 patients with a primary diagnosis of spinal sarcoma, with an average age of 48.6 ± 12.6 years. Chondrosarcoma emerged as the most common tumor type, representing 57.1% of cases, followed by Ewing sarcoma at 35.7%, and synovial sarcoma at 7.1%. Patients with chondrosarcoma were treated with en-bloc resection, while the patient with synovial sarcoma underwent intra-lesional excision and those with Ewing sarcoma received decompression and tumor debulking. Postoperative assessments revealed significant improvements in neurological conditions. Notably, functional status as measured by the Karnofski Performance Index (KPI), improved substantially post-surgery (from 61.4 to 80.0%) The mean follow-up was 34.9 ± 9.2 months. During this time period one patient experienced fatal bleeding after en-bloc resection complications involving the vena cava. None of the patient needed further surgery. CONCLUSIONS: Our 16-year study offers vital insights into managing primary spinal sarcomas, showcasing the effectiveness of surgical intervention, particularly en-bloc resection. Despite their rarity and complexity, our multidisciplinary treatment approach yields improved outcomes and highlights the potential for refined surgical strategies to become standardized care in this challenging domain.

Clival chordomas and chondrosarcomas in Denmark-Outcomes in 33 patients following the national centralization of treatment in 2010.

PURPOSE: This 13-year consecutive case series aims to provide a comprehensive overview of all patients operated for clival chordomas and clival chondrosarcomas in Denmark since the centralization of treatment in 2010, comparing outcomes to international series. METHODS: This was a retrospective review of 33 patients with clival tumors, comprising 22 chordomas and 11 chondrosarcomas, who were treated at Copenhagen University Hospital between years 2010 and 2023. Data were collected from digital patient records and pathology reports. RESULTS: The symptoms leading to diagnosis primarily included double vision, headaches, and dizziness. In general, patients were in good health, with a mean Charlson Comorbidity Index score of 1.6. The complication rate of the index surgery was 51.5%. Adjuvant radiotherapy was applied in 51.5% of the cases. In patients with clival chordomas, the mean age was 51.1 years, ranging from 16 to 83 years. At the time of diagnosis, the mean tumor volume was 20.9 cm3 and the five-year overall survival rates were 79.1% (95% confidence interval (CI): 62.4-100). In patients with chondrosarcomas, the mean age was 48.2 years, ranging from 15 to 76 years. At the time of diagnosis, the mean tumor volume was 22.3 cm3 and the five-year overall survival 90% (95% CI: 73.2-100). CONCLUSION: The centralized treatment of clival tumors in Denmark demonstrates incidence, survival, and complication rates comparable to those found in other international series. Given the variations in treatment strategies, tumor localizations across series, and small sample sizes, the further analysis of larger compiled multicenter datasets for clival tumors could provide more solid evidence regarding the management of these rare tumors.

Chondrosarcoma Co-Culture 3D Model─An Insight to Evaluate Drugs Acting on TAMs.

Chondrosarcoma (CHS), also known as malignant cartilage tumors, is the second most common bone cancer after osteosarcoma. This tumor is particularly chemo- and radioresistant, and the only therapeutic alternative is surgery with wide margins. The tumor immune microenvironment reveals an infiltration of tumor-associated macrophages (TAMs) sometimes approaching 50% of the tumor mass, mainly differentiated into M2-like phenotype and correlated with poor prognosis and metastasis. Thus, macrophage-targeting therapies could have an interest in the management of CHS. To evaluate these strategies, we propose here the development of a three-dimensional (3D) tumoroid co-culture model between two human CHS cell lines (JJ012 and CH2879) and a human leukemia monocytic cell line (THP-1) in a methylcellulose matrix. These two models were compared to the in vivo xenograft models in terms of macrophage phenotypes, proteoglycans, MMP-9, and COX-2 expression. Finally, mifamurtide, an immunomodulator acting on TAMs, was evaluated on the most in vitro relevant model: 3D co-culture CH2879 model. Our results showed that it is now possible to develop 3D models that very accurately mimic what is found in vivo with the possibility of evaluating treatments specific to a tumor cell component.

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.

Preoperative prediction of histopathological grading in patients with chondrosarcoma using MRI-based radiomics with semantic features.

BACKGROUND: Distinguishing high-grade from low-grade chondrosarcoma is extremely vital not only for guiding the development of personalized surgical treatment but also for predicting the prognosis of patients. We aimed to establish and validate a magnetic resonance imaging (MRI)-based nomogram for predicting preoperative grading in patients with chondrosarcoma. METHODS: Approximately 114 patients (60 and 54 cases with high-grade and low-grade chondrosarcoma, respectively) were recruited for this retrospective study. All patients were treated via surgery and histopathologically proven, and they were randomly divided into training (n = 80) and validation (n = 34) sets at a ratio of 7:3. Next, radiomics features were extracted from two sequences using the least absolute shrinkage and selection operator (LASSO) algorithms. The rad-scores were calculated and then subjected to logistic regression to develop a radiomics model. A nomogram combining independent predictive semantic features with radiomic by using multivariate logistic regression was established. The performance of each model was assessed by the receiver operating characteristic (ROC) curve analysis and the area under the curve, while clinical efficacy was evaluated via decision curve analysis (DCA). RESULTS: Ultimately, six optimal radiomics signatures were extracted from T1-weighted imaging (T1WI) and T2-weighted imaging with fat suppression (T2WI-FS) sequences to develop the radiomics model. Tumour cartilage abundance, which emerged as an independent predictor, was significantly related to chondrosarcoma grading (p < 0.05). The AUC values of the radiomics model were 0.85 (95% CI, 0.76 to 0.95) in the training sets, and the corresponding AUC values in the validation sets were 0.82 (95% CI, 0.65 to 0.98), which were far superior to the clinical model AUC values of 0.68 (95% CI, 0.58 to 0.79) in the training sets and 0.72 (95% CI, 0.57 to 0.87) in the validation sets. The nomogram demonstrated good performance in the preoperative distinction of chondrosarcoma. The DCA analysis revealed that the nomogram model had a markedly higher clinical usefulness in predicting chondrosarcoma grading preoperatively than either the rad-score or clinical model alone. CONCLUSION: The nomogram based on MRI radiomics combined with optimal independent factors had better performance for the preoperative differentiation between low-grade and high-grade chondrosarcoma and has potential as a noninvasive preoperative tool for personalizing clinical plans.

Presentation, treatment, and outcomes of chondrosarcoma in young adult patients less than age 50: A case series of ten patients.

ABSTRACT: Chondrosarcoma is an aggressive bone tumor typically affecting older adults in the 6th and 7th decade. These tumors often present as painful masses in the pelvis, ribs, and long bones and have certain characteristic features on the imaging leading to the diagnosis. The occurrence of these tumors in the young adult population is a rare condition that is not well described. Often, they may be confused with benign counterparts, enchondroma or osteochondroma, which does not require any treatment and are very common. The aim of this case series was to analyze the patient presentation and radiographic image findings as well as surgical treatment and outcomes of ten young adults with chondrosarcoma over a three-year period. Overall, imaging of these tumors in young adults did not necessarily demonstrate all typical features of chondrosarcomas such as endosteal scalloping, calcifications, lobular growth, and high uptake on whole-body bone scans. One patient in the case series passed away from complications from dedifferentiated chondrosarcoma, and nine patients have recovered with no local recurrence.

Combined Application of Cold Physical Plasma and Chemotherapeutics against Chondrosarcoma Cells.

Chondrosarcoma (CS) is a rare malignant bone sarcoma that primarily affects cartilage cells in the femur and pelvis. While most subtypes exhibit slow growth with a very good prognosis, some aggressive subtypes have a poorer overall survival. CS is known for its resistance to chemotherapy and radiotherapy, leaving surgery as the sole effective therapeutic option. Cold physical plasma (CPP) has been explored in vitro as a potential therapy, demonstrating positive anti-tumor effects on CS cells. This study investigated the synergistic effects of combining CPP with cytostatics on CS cells. The chemotherapeutic agents cisplatin, doxorubicin, and vincristine were applied to two CS cell lines (CAL-78 and SW1353). After determining their IC20 and IC50, they were combined with CPP in both cell lines to assess their impact on the cell proliferation, viability, metabolism, and apoptosis. This combined approach significantly reduced the cell proliferation and viability while increasing the apoptosis signals compared to cytostatic therapy alone. The combination of CPP and chemotherapeutic drugs shows promise in targeting chemoresistant CS cells, potentially improving the prognosis for patients in clinical settings.

Extraskeletal myxoid chondrosarcoma metastasis to a Meckel's diverticulum adenocarcinoma / Metástasis de condrosarcoma mixoide extraesquelético a un adenocarcinoma de divertículo de Meckel

Extraskeletal myxoid chondrosarcoma is a rare soft tissue tumour with a high local and distant metastasis rate and limited response to chemotherapy. Meckel's diverticulum is the most frequent congenital anomaly, and it is associated with a considerable risk of malignant transformation. In this case report, we describe a 50-year-old female patient with a history of extraskeletal myxoid chondrosarcoma of the lower limb and metastasis to the forearm who went to the emergency department with abdominal pain. The investigations revealed a caecal volvulus. A lesion in the middle third of the ileum was incidentally discovered and removed during surgery. Pathology examination revealed a Meckel's diverticulum adenocarcinoma, with metastasis of extraskeletal myxoid chondrosarcoma. Resection was complete; however, the patient had diffuse metastatic pulmonary disease and died eight months later due to disease progression. This mechanism of tumour-to-tumour metastasis is described in other locations, but, regarding the Meckel's diverticulum, this is a unique situation, previously unreported in the literature. (AU)

El condrosarcoma mixoide extraesquelético es un tumor de tejidos blandos poco frecuente, con una elevada tasa de recurrencia y metástasis a distancia y una respuesta limitada a la quimioterapia. El divertículo de Meckel es la anomalía congénita más frecuente y se asocia a un riesgo considerable de transformación maligna. En este caso clínico describimos a una paciente de 50 años con antecedentes de condrosarcoma mixoide extraesquelético de miembro inferior y metástasis en el antebrazo que acudió al servicio de urgencias por dolor abdominal. La exploración reveló un vólvulo cecal. Se descubrió incidentalmente una lesión en el tercio medio del íleon, que se extirpó durante la intervención quirúrgica. El examen patológico reveló un adenocarcinoma de divertículo de Meckel, afectado por metástasis de condrosarcoma mixoide extraesquelético. La resección fue completa; sin embargo, la paciente presentaba enfermedad pulmonar metastásica difusa y falleció ocho meses después debido a la progresión de la enfermedad. Este mecanismo de metástasis entre tumores está descrito en otras localizaciones, pero en lo que respecta al divertículo de Meckel, se trata de una situación única en la literatura. (AU)

Can the Cartilaginous Thickness Determine the Risk of Malignancy in Pelvic Cartilaginous Tumors, and How Accurate is the Preoperative Biopsy of These Tumors?

BACKGROUND: Peripheral osteochondral tumors are common, and the management of tumors presenting in the pelvis is challenging and a controversial topic. Some have suggested that cartilage cap thickness may indicate malignant potential, but this supposition is not well validated. QUESTIONS/PURPOSES: (1) How accurate is preoperative biopsy in determining whether a peripheral cartilage tumor of the pelvis is benign or malignant? (2) Is the thickness of the cartilage cap as determined by MRI associated with the likelihood that a given peripheral cartilage tumor is malignant? (3) What is local recurrence-free survival (LRFS), metastasis-free survival (MFS), and disease-specific survival (DSS) in peripheral chondrosarcoma of the pelvis and is it associated with surgical margin? METHODS: Between 2005 and 2022, 289 patients had diagnoses of peripheral cartilage tumors of the pelvis (either pedunculated or sessile) and were treated at one tertiary sarcoma center (the Royal Orthopaedic Hospital, Birmingham, UK). These patients were identified retrospectively from a longitudinally maintained institutional database. Those whose tumors were asymptomatic and discovered incidentally and had cartilage caps ≤ 1.5 cm were discharged (95 patients), leaving 194 patients with tumors that were either symptomatic or had cartilage caps > 1.5 cm. Tumors that were asymptomatic and had a cartilage cap > 1.5 cm were followed with MRIs for 2 years and discharged without biopsy if the tumors did not grow or change in appearance (15 patients). Patients with symptomatic tumors that had cartilage caps ≤ 1.5 cm underwent removal without biopsy (63 patients). A total of 82 patients (63 with caps ≤ 1.5 cm and 19 with caps > 1.5 cm, whose treatment deviated from the routine at the time) had their tumors removed without biopsy. This left 97 patients who underwent biopsy before removal of peripheral cartilage tumors of the pelvis, and this was the group we used to answer research question 1. The thickness of the cartilage cap was recorded from MRI and measuring to the nearest millimeter, with measurements taken perpendicular in the plane that best allowed the greatest measurement. Patient survival rates were assessed using the Kaplan-Meier method with 95% confidence intervals as median observation times to estimate MFS, LRFS, and DSS. RESULTS: Of malignant tumors biopsied, in 49% (40 of 82), the biopsy result was recorded as benign (or was considered uncertain regarding malignancy). A malignant diagnosis was correctly reported in biopsy reports in 51% (42 of 82) of patients, and if biopsy samples with uncertainty regarding malignancy were excluded, the biopsy identified a lesion as being malignant in 84% (42 of 50) of patients. The biopsy results correlated with the final histologic grade as recorded from the resected specimen in only 33% (27 of 82) of patients. Among these 82 patients, 15 biopsies underestimated the final histologic grade. The median cartilage cap thickness for all benign osteochondromas was 0.5 cm (range 0.1 to 4.0 cm), and the median cartilage cap thickness for malignant peripheral chondrosarcomas was 8.0 cm (range 3.0 to 19 cm, difference of medians 7.5 cm; p < 0.01). LRFS was 49% (95% CI 35% to 63%) at 3 years for patients with malignant peripheral tumors with < 1-mm margins, and LRFS was 97% (95% CI 92% to 100%) for patients with malignant peripheral tumors with ≥ 1-mm margins (p < 0.01). DSS was 100% at 3 years for Grade 1 chondrosarcomas, 94% (95% CI 86% to 100%) at 3 years for Grade 2 chondrosarcomas, 73% (95% CI 47% to 99%) at 3 and 5 years for Grade 3 chondrosarcomas, and 20% (95% CI 0% to 55%) at 3 and 5 years for dedifferentiated chondrosarcomas (p < 0.01). DSS was 87% (95% CI 78% to 96%) at 3 years for patients with malignant peripheral tumors with < 1-mm margin, and DSS was 100% at 3 years for patients with malignant peripheral tumors with ≥ 1-mm margins (p = 0.01). CONCLUSION: A thin cartilage cap (< 3 cm) is characteristic of benign osteochondroma. The likelihood of a cartilage tumor being malignant increases after the cartilage cap thickness exceeds 3 cm. In our experience, preoperative biopsy results were not reliably associated with the final histologic grade or malignancy, being accurate in only 33% of patients. We therefore recommend observation for 2 years for patients with pelvic osteochondromas in which the cap thickness is < 1.5 cm and there is no associated pain. For patients with tumors in which the cap thickness is 1.5 to 3 cm, we recommend either close observation for 2 years or resection, depending on the treating physician's decision. We recommend excision in patients whose pelvic osteochondromas show an increase in thickness or pain, preferably before the cartilage cap thickness is 3 cm. We propose that surgical resection of peripheral cartilage tumors in which the cartilage cap exceeds 3 cm (aiming for clear margins) is reasonable without preoperative biopsy; the role of preoperative biopsy is less helpful because radiologic measurement of the cartilage cap thickness appears to be accurately associated with malignancy. Biopsy might be helpful in patients in whom there is diagnostic uncertainty or when confirming the necessity of extensive surgical procedures. Future studies should evaluate other preoperative tumor qualities in differentiating malignant peripheral cartilage tumors from benign tumors. LEVEL OF EVIDENCE: Level III, diagnostic study.

Application of microwave ablation assisted degradation therapy in surgical treatment of intramedullary chondrosarcoma of extremities.

AIM: Clinical diagnosis and surgical treatment of chondrosarcoma (CS) are continuously improving. The purpose of our study is to evaluate the effectiveness of microwave ablation (MWA) assisted degradation therapy in the surgical treatment of intramedullary chondrosarcoma of the extremities, to provide a new reference and research basis for the surgical treatment of CS. METHODS: We recruited 36 patients with intramedullary CS who underwent MWA assisted extended curettage. Preoperative patient demographics and clinical data were recorded. Surgery was independently assisted by a medical team. Patients were followed up strictly and evaluated for oncological prognosis, radiological results, limb joint function, pain, and complications. RESULTS: We included 15 men and 21 women (mean age: 43.5 ± 10.1). The average length of the lesion was 8.1 ± 2.5 cm. Based on preoperative radiographic, clinical manifestations, and pathological results of puncture biopsy, 28 patients were preliminarily diagnosed with CS-grade I and eight patients with CS-grade II. No recurrence or metastasis occurred in the postoperative follow-up. The average Musculoskeletal Tumor Society score was 28.8 ± 1.0, significantly better than presurgery. Secondary shoulder periarthritis and abduction dysfunction occurred in early postoperative stage CS of the proximal humerus in some, but returned to normal after rehabilitation exercise. Secondary bursitis occurred at the knee joint in some due to the internal fixation device used in treatment; however, secondary osteoarthritis and avascular necrosis of the femoral head were not observed. Overall, oncological and functional prognoses were satisfactory. CONCLUSIONS: The application of MWA assisted degradation therapy in intramedullary CS can achieve satisfactory oncology and functional prognosis, providing a new option for the limited treatment of CS.

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.

DNA-PKcs Inhibition Sensitizes Human Chondrosarcoma Cells to Carbon Ion Irradiation via Cell Cycle Arrest and Telomere Capping Disruption.

In order to overcome the resistance to radiotherapy in human chondrosarcoma cells, the prevention from efficient DNA repair with a combined treatment with the DNA-dependent protein kinase catalytic subunit (DNA-PKcs) inhibitor AZD7648 was explored for carbon ion (C-ion) as well as reference photon (X-ray) irradiation (IR) using gene expression analysis, flow cytometry, protein phosphorylation, and telomere length shortening. Proliferation markers and cell cycle distribution changed significantly after combined treatment, revealing a prominent G2/M arrest. The expression of the G2/M checkpoint genes cyclin B, CDK1, and WEE1 was significantly reduced by IR alone and the combined treatment. While IR alone showed no effects, additional AZD7648 treatment resulted in a dose-dependent reduction in AKT phosphorylation and an increase in Chk2 phosphorylation. Twenty-four hours after IR, the key genes of DNA repair mechanisms were reduced by the combined treatment, which led to impaired DNA repair and increased radiosensitivity. A time-dependent shortening of telomere length was observed in both cell lines after combined treatment with AZD7648 and 8 Gy X-ray/C-ion IR. Our data suggest that the inhibition of DNA-PKcs may increase sensitivity to X-rays and C-ion IR by impairing its functional role in DNA repair mechanisms and telomere end protection.

Controversies in orthopaedic oncology.

Chondrosarcoma is the second most common surgically treated primary bone sarcoma. Despite a large number of scientific papers in the literature, there is still significant controversy about diagnostics, treatment of the primary tumour, subtypes, and complications. Therefore, consensus on its day-to-day treatment decisions is needed. In January 2024, the Birmingham Orthopaedic Oncology Meeting (BOOM) attempted to gain global consensus from 300 delegates from over 50 countries. The meeting focused on these critical areas and aimed to generate consensus statements based on evidence amalgamation and expert opinion from diverse geographical regions. In parallel, periprosthetic joint infection (PJI) in oncological reconstructions poses unique challenges due to factors such as adjuvant treatments, large exposures, and the complexity of surgery. The meeting debated two-stage revisions, antibiotic prophylaxis, managing acute PJI in patients undergoing chemotherapy, and defining the best strategies for wound management and allograft reconstruction. The objectives of the meeting extended beyond resolving immediate controversies. It sought to foster global collaboration among specialists attending the meeting, and to encourage future research projects to address unsolved dilemmas. By highlighting areas of disagreement and promoting collaborative research endeavours, this initiative aims to enhance treatment standards and potentially improve outcomes for patients globally. This paper sets out some of the controversies and questions that were debated in the meeting.

Soft Tissue Reconstruction After Sacral Neoplasm Resection: The University of California San Francisco Experience.

PURPOSE: Resection of sacral neoplasms such as chordoma and chondrosarcoma with subsequent reconstruction of large soft tissue defects is a complex multidisciplinary process. Radiotherapy and prior abdominal surgery play a role in reconstructive planning; however, there is no consensus on how to maximize outcomes. In this study, we present our institution's experience with the reconstructive surgical management of this unique patient population. METHODS: We conducted a retrospective review of patients who underwent reconstruction after resection of primary or recurrent pelvic chordoma or chondrosarcoma between 2002 and 2019. Surgical details, hospital stay, and postoperative outcomes were assessed. Patients were divided into 3 groups for comparison based on reconstruction technique: gluteal-based flaps, vertical rectus abdominus myocutaneous (VRAM) flaps, and locoregional fasciocutaneous flaps. RESULTS: Twenty-eight patients (17 males, 11 females), with mean age of 62 years (range, 34-86 years), were reviewed. Twenty-two patients (78.6%) received gluteal-based flaps, 3 patients (10.7%) received VRAM flaps, and 3 patients (10.7%) were reconstructed with locoregional fasciocutaneous flaps. Patients in the VRAM group were significantly more likely to have undergone total sacrectomy (P < 0.01) in a 2-stage operation (P < 0.01) compared with patients in the other 2 groups. Patients in the VRAM group also had a significantly greater average number of reoperations (2 ± 3.5, P = 0.04) and length of stay (29.7 ± 20.4 days, P = 0.01) compared with the 2 other groups. The overall minor and major wound complication rates were 17.9% and 42.9%, respectively, with 17.9% of patients experiencing at least 1 infection or seroma. There was no association between prior abdominal surgery, surgical stages, or radiation therapy and an increased risk of wound complications. CONCLUSIONS: Vertical rectus abdominus myocutaneous flaps are a more suitable option for patients with larger defects after total sacrectomy via 2-staged anteroposterior resections, whereas gluteal myocutaneous flaps are effective options for posterior-only resections. For patients with small- to moderate-sized defects, local fasciocutaneous flaps are a less invasive and effective option. Paraspinous flaps may be used in combination with other techniques to provide additional bulk and coverage for especially long postresection wounds. Furthermore, mesh is a useful adjunct for any reconstruction aimed at protecting against intra-abdominal complications.