Update on chondrosarcomas

Virtual planning, guided surgery, and digital prosthodontics in the treatment of extended mandible chondrosarcoma

Chondrosarcoma is among the most common primary bone tumors in adults. In the mandible, chondrosarcoma is a very uncommon malignant cartilage-producing tumor. This case report shows how virtual planning combined with other digital technologies may improve masticatory function rehabilitation in patients with enlarged mandibular chondrosarcoma. The present study reports a case of a 52-year-old male patient who was initially diagnosed with a mandible chondroma, which was successfully excised with no evidence of malignant transformation. Nevertheless, the patient's symptoms recurred after 10 years, and a subsequent diagnosis of mandible chondrosarcoma was established, prompting the need for subtotal mandible resection and reconstruction with a fibula-free flap. Following a healing period, the patient underwent dental implant surgery to restore the mandibular dental arch, which was performed utilizing computer-aided design and computer-aided manufacturing technology, with fully guided implant placement facilitated by virtual planning. In this case report, the implant position data merging process is described from the digital impression and control model to ensure optimal passive fit of the full-arch zirconia prosthesis and discuss the importance of occlusal adjustments to avoid technical and biological complications. Virtual planning and digital technologies are crucial for the effective management of mandibular defects, allowing for accurate treatment and complete restoration of mandibular function. Their use leads to improved patient outcomes and quality of life. As technology advances, their importance in treating complex medical conditions is only expected to grow.

New advances in the treatment of chondrosarcoma under the PD-1/PD-L1 pathway

ABSTRACT

Bone sarcomas encompass a group of spontaneous mesenchymal malignancies, among which osteosarcoma, Ewing sarcoma, chondrosarcoma, and chordoma are the most common subtypes. Chondrosarcoma, a relatively prevalent malignant bone tumor that originates from chondrocytes, is characterized by endogenous cartilage ossification within the tumor tissue. Despite the use of aggressive treatment approaches involving extensive surgical resection, chemotherapy, and radiotherapy for patients with osteosarcoma, chondrosarcoma, and chordoma, limited improvements in patient outcomes have been observed. Furthermore, resistance to chemotherapy and radiation therapy has been observed in chondrosarcoma and chordoma cases. Consequently, novel therapeutic approaches for bone sarcomas, including chondrosarcoma, need to be uncovered. Recently, the emergence of immunotherapy and immune checkpoint inhibitors has garnered attention given their clinical success in various diverse types of cancer, thereby prompting investigations into their potential for managing chondrosarcoma. Considering that circumvention of immune surveillance is considered a key factor in the malignant progression of tumors and that immune checkpoints play an important role in modulating antitumor immune effects, blockers or inhibitors targeting these immune checkpoints have become effective therapeutic tools for patients with tumors. One such checkpoint receptor implicated in this process is programmed cell death protein-1 (PD-1). The association between PD-1 and programmed cell death ligand-1 (PD-L1) and cancer progression in humans has been extensively studied, highlighting their remarkable potential as biomarkers for cancer treatment. This review comprehensively examines available studies on current chondrosarcoma treatments and advancements in anti-PD-1/PD-L1 blockade therapy for chondrosarcoma.

A 30-year bibliometric analysis of the literature in the disciplines of orthopedics, surgery, or oncology on chondrosarcoma from 1993 to 2023

BACKGROUND

A thorough bibliometric analysis of publications published in the field of chondrosarcoma research has not yet been performed using the Web of Science database, especially for publications published between 1993 and 2023. This study, with a focus on the fields of orthopedics, surgery, and oncology, aims to fill this knowledge gap by providing a thorough analysis of current knowledge in the field of chondrosarcoma.

METHODS

In this bibliometric study, a literature search was performed using the Web of Science database to find all publications on chondrosarcoma. A bibliometric software program was used for data visualization and analysis (opensource visualization application, Vosviewer). The Web of Science Core Collection data used for this retrospective bibliometric study, which covers the period from January 1993 to September 2023, revealed interesting trends in chondrosarcoma research.

RESULTS

As the most popular fields of study, orthopedics, surgery, and oncology account for a sizable portion of publications. A noteworthy increase in research output from 2014 to 2023, accounting for 41.74% of the papers, reflects the thriving research environment. The leading countries for publication were China, Japan, and the United States, demonstrating cross-border cooperation in chondrosarcoma research. Their contributions were highlighted by their important affiliations with institutions such as Harvard University, Leiden University, and China Medical University Taiwan. A thorough keyword mapping analysis also highlighted research priorities and encouraged interdisciplinary cooperation. The field's scholarly importance and ongoing relevance are highlighted by the study's high citation count (30,076) and highly cited articles.

CONCLUSION

Overall, this study offers crucial insights into the development and collaborative nature of the chondrosarcoma research landscape and its long-lasting influence on academic research and clinical practice.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

CRITICAL RELEVANCE STATEMENT

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

KEY POINTS

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

Proton Therapy for Skull Base Chondrosarcoma

Chondrosarcoma is a type of an endochondral bone malignancy that is primarily treated surgically with radiation therapy used in the adjuvant setting or in cases of unresectable disease. Proton therapy has potential advantages compared with traditional photon therapy for the treatment of tumors in close proximity to critical structures due to the theoretic lower exit dose. Studies have shown improved survival in patients with skull base chondrosarcoma who undergo proton therapy. However, there is a lack of randomized data. Further studies are needed to define the role of proton therapy in the treatment of skull base chondrosarcoma.

Role of immunotherapy in chondrosarcoma: A case report and review of the literature

Chondrosarcomas (CSs) consist of a heterogenous group of primary bone cancers arising from malignant cells which produce cartilaginous matrix. As the second most common primary bone cancer, CS are often resistant to systemic chemotherapy due to poor vascularization, slow proliferation, and expression of multidrug-resistant pumps. Immune checkpoint inhibitors have transformed the field of oncology and are now designated as frontline therapy for many solid tumor cancers. Several studies have demonstrated increased expression of programed cell death 1 (PD-1) and PD-L1 in CS tissue in vitro, which has led to the development of multiple clinical trials for immunotherapy in patients with aggressive CS. In this review, we highlight the ongoing investigation into the role for immunotherapy in CS. We also report the case of a 44-year-old female with a history of stage IV primary CS of the right shoulder who underwent radical resection with recurrence and demonstrated a spectacular sustained response to pembrolizumab at our center. Our review highlights the need for further studies investigating the role of immunotherapy in the treatment of aggressive bone sarcomas that are resistant to standard surgical resection, chemotherapy, and radiation treatment.

Curettage or Resection? A Review on the Surgical Treatment of Low-Grade Chondrosarcomas

Introduction Low-grade chondrosarcomas (LG-CS), including atypical cartilaginous tumors (ACT), are locally aggressive lesions. The focus of the discussion sits on the differential diagnosis between benign lesions or aggressive cartilaginous tumors and on their treatment: intralesional curettage or wide resection. This study presents the results obtained in the surgical treatment of 21 cases of LG-CS. Methods This retrospective study includes 21 consecutive patients from a single center with LG-CS who underwent surgery from 2013 to 2021. Fourteen were located in the appendicular skeleton, and seven in the axial (shoulder blade, spine, or pelvis). Mortality rate, recurrence, metastatic disease, overall survival, recurrence-free survival, and metastatic disease-free survival were analyzed for each type of procedure and each disease location. Operative complications and residual tumors were also recorded in cases where resection was performed. Survival was calculated using the Kaplan-Meier method. Results Thirteen patients underwent intralesional curettage (11 appendicular and 2 axial lesions), and eight underwent wide resection (5 axial and 3 appendicular). There were six recurrences during the follow-up, 43% of the axial lesions recurred, rising to 100% in axial curetted ones. Appendicular LG-CS recurred in 21% of cases, and only 18% of curetted appendicular lesions were not eradicated. The overall survival for the entire follow-up is 90.5%, and the 5-year survival rate is 83% (12 patients have adequate follow-up). Recurrence-free and metastasis-free survival were higher in resection cases, with 75% and 87.5%, vs. curettage 69.2% and 76.9%, respectively. In 9% of cases, the preoperative biopsy was inconsistent with the pathology of the surgical specimen. Discussion LG-CS and ACT are described as having high survival and low potential for metastatic disease. For this reason, these lesions are subject to a change in treatment philosophy to reflect these characteristics. Intra-lesional curettage is advocated as a less invasive technique for eradicating atypical cartilage tumors and has fewer and less severe complications, which was in accordance with our findings. Diagnosis, however, is challenging; misgrading is frequent and should be considered. Because of this risk of under-treating higher-grade lesions, some authors still defend wide-resection as the treatment of choice. We observed a trend towards longer survival, less recurrence, and metastatic disease with wide resection. Metastatic disease was higher than expected, present in 19% of cases, and always associated with local recurrence. Conclusion LG-CS is still a diagnostic and treatment challenge; patient selection is fundamental. Overall survival is high, independent of treatment choice or lesion location. We found a higher rate of metastatic disease than described in the literature; this, coupled with a misgrading rate of 9%, reflects the difficulty of preoperative diagnosis and the risk of treating high-grade chondrosarcomas as a low-grade lesion. More studies should be carried out with larger samples to obtain statistically robust results.

Rare presentation of intra-spinal extradural grade 1 chondrosarcoma: A case report

Introduction

Lumbar Spine Chondrosarcomas are rare entities that accounts for less than 10% of all spinal Chondrosarcomas, patients can present with symptoms of nerve root irritation secondary to direct compression caused by the tumor mass effect. Radiologically these tumors are destructive in nature with soft tissues classifications, and the treatment of choice for it is complete surgical excision, however in some scenarios they are difficult to access and complete resection becomes not feasible.

Presentation of case

A 37 years old male, presented to our spine clinic with chief complaint of chronic low back pain with radicular symptoms, normal power in both lower limbs, while his radiological evaluation showed intra-spinal extra-dural Chondrosarcoma arising from the posterior cortex of the 5th vertebral body, for which he underwent surgical decompression of the lumbar canal with resection of the lesion and unilateral stabilization of the spinal segment.

Conclusions

Unlike Chondrosarcomas of the appendicular skeleton, lesions arising in the spinal element may be difficult to detect on plain radiographs and further imaging is crucial for better evaluation, as this will help in surgical planning for excision of the tumor. In difficult cases with inaccessible locations, marginal excision of spinal Chondrosarcomas can be achieved utilizing a minimally invasive technique with preservation of some spine motion with acceptable clinical outcomes.

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Lumbar Spine Chondrosarcomas are rare entities that accounts for less than 10% of all spinal Chondrosarcomas

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Treatment of Chondrosarcomas consistent of complete surgical excision.

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Sometimes these tumors are difficult to access, and complete excision becomes not feasible.

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In difficult accessible cases Marginal excision with unilateral stability of these tumors may be sufficient with acceptable clinical outcome.

New Approach against Chondrosoma Cells-Cold Plasma Treatment Inhibits Cell Motility and Metabolism, and Leads to Apoptosis

(1) Background: Chondrosarcoma (CS) is a malignant primary bone tumor with a cartilaginous origin. Its slow cell division and severely restricted vascularization are responsible for its poor responsiveness to chemotherapy and radiotherapy. The decisive factor for the prognosis of CS patients is the only adequate therapy-surgical resection. Cold atmospheric pressure plasma (CAP) is emerging as a new option in anti-cancer therapy. Its effect on chondrosarcomas has been poorly investigated. (2) Methods: Two CS cell lines-SW 1353 and CAL 78-were used. Various assays, such as cell growth kinetics, glucose uptake, and metabolic activity assay, along with two different apoptosis assays were performed after CAP treatment. A radius cell migration assay was used to examine cell motility. (3) Results: Both cell lines showed different growth behavior, which was taken into account when using the assays. After CAP treatment, a reduction in metabolic activity was observed in both cell lines. The immediate effect of CAP showed a reduction in cell numbers and in influence on this cell line's growth rate. The measurement of the glucose concentration in the cell culture medium showed an increase after CAP treatment. Live-dead cell imaging shows an increase in the proportion of dead cells over the incubation time for both cell lines. There was a significant increase in apoptotic signals after 48 h and 72 h for both cell lines in both assays. The migration assay showed that CAP treatment inhibited the motility of chondrosarcoma cells. The effects in all experiments were related to the duration of CAP exposure. (4) Conclusions: The CAP treatment of CS cells inhibits their growth, motility, and metabolism by initiating apoptotic processes.

Primary osseous chondrosarcoma in the lumbar spine: case report and literature review with analysis

Primary spinal chondrosarcoma (CS) is rare. Only a few previous case reports have included a detailed description of the surgical process used to treat the CS. In addition, a paucity of documentation exists comparing differences in the outcomes between the approaches in en bloc resection. Here, we present a case of CS in the lumbar (L) spine treated with two-stage (anterior and posterior approach) en bloc surgery and analyze the differences between one-stage and two-stage approaches in the treatment of primary lumbar CS. A 30-year-old male patient with an L3 vertebral body CS presented with back pain and lower limb weakness. Lumbar spine magnetic resonance imaging (MRI) showed an L3 vertebral body tumor with cord and root compression. Two-stage surgery comprising posterior total laminectomy and transpedicular screw fixation over L2–L4 in the first stage, with subsequent anterior corpectomy, cage implantation, and anterior lumbar interbody fusion was performed to achieve total tumor removal and stabilization. The patient’s symptoms improved postoperatively, with no recurrence as of the 2-year follow-up. The analysis of previous similar cases showed that two-stage surgery, compared with one-stage surgery, appears to be beneficial in lumbar spine multisegment disease, providing a lower recurrence rate.

Outcomes and Patterns of Care in Adult Skull Base Chondrosarcoma Patients in the United States

BACKGROUND

Chondrosarcomas of the skull base are rare intracranial tumors of chondroid origin. The rarity of these lesions has made it difficult to form a consensus on optimal treatment regimens. The aim of this study was to provide a comprehensive analysis of prognostic factors, treatment modalities, and survival outcomes in patients with chondrosarcoma of the skull base.

METHODS

Patients with diagnosis codes for chondrosarcoma of the skull base were queried from the National Cancer Database for the years 2004-2016. Outcomes were investigated using Cox univariate and multivariate regression analyses, and survival curves were generated for comparative visualization.

RESULTS

A total of 718 patients with chondrosarcoma of the skull base were identified. Mean overall survival (OS) in these patients was 10.7 years. Older age and presence of metastases were associated with worsened OS. Of patients, 83.3% received surgical intervention, and both partial resection and radical resection were associated with significantly improved OS (P < 0.001). Neither radiotherapy nor chemotherapy improved OS; however, patients who received proton-based radiation and patients who received high-dose radiation (≥6000 cGy) had significantly improved OS compared with patients who received traditional radiation.

CONCLUSIONS

In the largest study to our knowledge of skull base chondrosarcoma to date, both partial resection and radical resection significantly improved OS, thus supporting the goal of maximal safe resection to preserve vital neurovascular structures without sacrificing outcome. In patients who received radiotherapy, proton-based modalities and high-dose radiation were associated with increased OS.

Clinical efficiency of epigenetic drugs therapy in bone malignancies

A great interest in the scientific community is focused on the improvement of the cure rate in patients with bone malignancies that have a poor response to the first line of therapies. Novel treatments currently include epigenetic compounds or molecules targeting epigenetic-sensitive pathways. Here, we offer an exhaustive review of such agents in these clinical settings. Carefully designed preclinical studies selected several epigenetic drugs, including inhibitors of DNA methyltransferase (DNMTIs), such as Decitabine, histone deacetylase classes I-II (HDACIs), as Entinostat, Belinostat, lysine-specific histone demethylase (LSD1), as INCB059872 or FT-2102 (Olutasidenib), inhibitors of isocitrate dehydrogenases, and enhancer of zeste homolog 2 (EZH2), such as EPZ6438 (Tazemetostat) To enhance the therapeutic effect, the prevalent approach in phase II trial is the association of these epigenetic drug inhibitors, with targeted therapy or immune checkpoint blockade. Optimization of drug dosing and regimens of Phase II trials may improve the clinical efficiency of such novel therapeutic approaches against these devastating cancers.

Chondrosarcoma of the Ribs

Chondrosarcoma is a unique kind of tumor that originates from the cartilage-producing neoplastic mesenchymal cells and appears in both the appendicular and atlantoaxial skeleton. It is the second most prevalent neoplastic bone tumor, with an occurrence of 0.79/100,000/year. The biological presentation of this cancer fluctuates extensively, depending on the grade and anatomical location. Since chondrosarcoma is predominantly resistant to conventional chemo- and radiation therapy, surgical resection remains the sole curative treatment, although at present new treatment modalities are under investigation.

Lumican mediates HTB94 chondrosarcoma cell growth via an IGF‑IR/Erk1/2 axis

Chondrosarcoma is a malignant bone tumor characterized by the production of a modified cartilage-type extracellular matrix (ECM). In the present study, the expression levels of the small leucine-rich proteoglycans (SLRPs), decorin, biglycan and lumican, were examined in the HTB94 human chondrosarcoma cell line. HTB94 cells were found to express and secrete the 3 SLRP members. RT-qPCR and western blot analysis demonstrated that lumican was the most abundantly secreted SLRP, whereas decorin and biglycan expression levels were low. The utilization of short interfering RNA specific for the decorin, biglycan, and lumican genes resulted in the efficient downregulation of the respective mRNA levels (P≤0.001). The growth of the HTB94 cells was stimulated by lumican (P≤0.001), whereas their migration and adhesion were not affected (P=NS). By contrast, these cellular functions were not sensitive to a decrease in low endogenous levels of decorin and biglycan. Lumicandeficiency significantly inhibited both basal and insulin-like growth factor I (IGF-I)-induced HTB94 cell growth (P≤0.001 andP≤0.01, respectively). These effects were executed through the insulin-like growth factor I receptor (IGF-IR), whose activation was markedly attenuated (P≤0.01) in lumican-deficient HTB94 cells. The downregulation of lumican induced the substantial inhibition of extracellular regulated kinase (ERK1/2) activation (P≤ 0.01), indicating that ERK1/2 is a necessary component of lumican/IGF-IR-mediated HTB94 cell proliferation. Moreover, the lumican-deficient cells exhibit increased mRNA levels of p53 (P≤0.05), suggesting that lumican facilitates HTB94 cell growth through an IGF-IR/ERK1/2/p53 signaling cascade. On the whole, the findings of the present study demonstrate that endogenous lumican is a novel regulator of HTB94 cell growth.

Treatment method and prognostic factors of chondrosarcoma: based on Surveillance, Epidemiology, and End Results (SEER) database

BACKGROUND

Chondrosarcoma is a malignant tumor originating from cartilage tissue. It is the second most malignant bone tumor, accounting for about 10% to 15% of all primary bone tumors. So far, there have been no reports of large-scale clinical statistics on the relationship between non-surgical treatment and prognosis in patients with chondrosarcoma.

METHODS

Through the search of the Surveillance, Epidemiology, and End Results (SEER) database, chondrosarcoma patients registered between January 1, 2004 and December 31, 2016 were selected as research goals. Univariate analysis of overall survival (OS) and chondrosarcoma-specific survival (CSSS) by Kaplan-Meier survival analysis and log-rank test. Mapping Kaplan-Meier curves for prognostic factors that are significant for OS and CSSS in patients with chondrosarcoma. After univariate analysis, the prognostic factors that have a significant effect on the prognosis were included in the multivariate Cox regression analysis, and the independent factors that affected the prognosis were screened.

RESULTS

A total of 1,128 patients with chondrosarcoma were included in the study. Univariate analysis showed that prognostic factors such as age, gender, primary site, histological type, grade, tumor size, metastasis, surgery, radiotherapy, chemotherapy and treatment method had significant effects on all-cause mortality (ACM) and chondrosarcoma-specific mortality (CSSM). These factors were included in the multivariate Cox regression analysis. The results showed age, primary site, histological type, grade, tumor size, metastasis, and treatment method were independent factors affecting ACM and CSSM.

CONCLUSIONS

This study found that although non-surgical treatment of chondrosarcoma has made great progress, at present, it is still not considered that non-surgical treatment can significantly improve the prognosis. There are many factors affecting the prognosis of chondrosarcoma, including age, primary site, histological type, grade, tumor size, distant metastasis and treatment method. In the future, more samples and more detailed data will be needed to study the treatment of chondrosarcoma and to analyze the important factors affecting prognosis through big data analysis.

Bone up on spinal osseous lesions: a case review series

Spinal osseous neoplasms are frequently encountered and can be challenging when present as solitary lesions. Familiarity with the range of benign and malignant spinal pathology can help the radiologist formulate a comprehensive differential diagnosis. This article focuses on the spectrum of extradural spinal tumors, accounting for the majority of primary spinal tumors, by comparing the epidemiology, pathophysiology, clinical presentation, and characteristic imaging appearance of these lesions. The discussion includes the commonly encountered benign lesions, such as vertebral venous vascular malformation and enostosis, as well as malignant lesions including metastases and lymphoma. The article also includes other less-encountered primary spinal tumors such as plasmacytoma, osteoid osteoma, osteoblastoma, giant cell tumor, eosinophilic granuloma, chordoma, chondrosarcoma, osteosarcoma, Ewing’s sarcoma, and angiosarcoma. Familiarity with the characteristic imaging features can help the radiologist reach an accurate diagnosis and obviate the need for unnecessary invasive procedures such as biopsy and surgery.

Cold Atmospheric Plasma Treatment of Chondrosarcoma Cells Affects Proliferation and Cell Membrane Permeability

Chondrosarcoma is the second most common malign bone tumor in adults. Surgical resection of the tumor is recommended because of its resistance to clinical treatment such as chemotherapy and radiation therapy. Thus, the prognosis for patients mainly depends on sufficient surgical resection. Due to this, research on alternative therapies is needed. Cold atmospheric plasma (CAP) is an ionized gas that contains various reactive species. Previous studies have shown an anti-oncogenic potential of CAP on different cancer cell types. The current study examined the effects of treatment with CAP on two chondrosarcoma cell lines (CAL-78, SW1353). Through proliferation assay, the cell growth after CAP-treatment was determined. A strong antiproliferative effect for both cell lines was detected. By fluorescein diacetate (FDA) assay and ATP release assay, alterations in the cell membrane and associated translocation of low molecular weight particles through the cytoplasmic membrane were observed. In supernatant, the non-membrane-permeable FDA and endogenously synthesized ATP detected suggest an increased membrane permeability after CAP treatment. Similar results were shown by the dextran-uptake assay. Furthermore, fluorescence microscopic G-/F-actin assay was performed. G- and F-actin were selectively dyed, and the ratio was measured. The presented results indicate CAP-induced changes in cell membrane function and possible alterations in actin-cytoskeleton, which may contribute to the antiproliferative effects of CAP.

The giant aggressive chondroma: A rare entity, a difficult approach

Introduction

enchondromas rarely exceed 3-6 cm in long bones. Although the risk of developing secondary chondrosarcoma has been reported up to 4% in solitary lesions, it is not known if size represents a risk factor for transformation.

Objective

to describe three exceptional cases of enchondromas of the entire femur whereof one dedifferentiated in chondrosarcoma.

Results

two patients present stable disease at 5 and 6 years of follow-up; the third, already diagnosed with a dedifferentiated chondrosarcoma, died 14 months after the index surgery for systemic disease.

Conclusion

based on these observations, our hypothesis is that lesion size is an important risk factor for malignant transformation.

FDG PET Hybrid Imaging

Molecular imaging with positron emission tomography (PET) using tumour-seeking radiopharmaceuticals has gained wide acceptance in oncology with many clinical applications. The hybrid imaging modality PET/CT (computed tomography) allows assessing molecular as well as morphologic information at the same time. Therefore, PET/CT represents an efficient tool for whole-body staging and re-staging within one imaging modality. In oncology, the glucose analogue 18-F-fluorodeoxyglucose (FDG) is the most widely used PET/CT radiopharmaceutical in clinical routine. FDG PET and FDG PET/CT have been used for staging and re-staging of tumour patients in numerous studies. This chapter will discuss the use and the main indications of FDG PET/CT in oncology with special emphasis on lung cancer, lymphoma, head and neck cancer, melanoma and breast cancer (among other tumour entities). A review of the current literature is given with respect to primary diagnosis, staging and diagnosis of recurrent disease. Besides its integral role in diagnosis, staging and re-staging of disease in oncology, there is increasing evidence that FDG PET/CT can be used for therapy response assessment (possibly influencing therapeutic management and treatment planning) by evaluating tumour control, which will also be discussed in this chapter.

Primary Bone Tumors: Challenges and Opportunities for CAR-T Therapies

Primary malignant bone tumors are rare, occur in all age groups, and include distinct entities such as osteosarcoma, Ewing sarcoma, and chondrosarcoma. Traditional treatment with some combination of chemotherapy, surgery, and radiation has reached the limit of efficacy, with substantial room for improvement in patient outcome. Furthermore, genomic characterization of these tumors reveals a paucity of actionable molecular targets. Against this backdrop, recent advances in cancer immunotherapy represent a silver lining in the treatment of primary bone cancer. Major strategies in cancer immunotherapy include stimulating naturally occurring anti-tumor T cells and adoptive transfer of tumor-specific cytotoxic T cells. Chimeric antigen receptor T cells (CAR-T cells) belong to the latter strategy and are an impressive application of both insights into T cell biology and advances in genetic engineering. In this review, we briefly describe the CAR-T approach and discuss its applications in primary bone tumors. © 2019 American Society for Bone and Mineral Research.

Results of a prospective phase 2 study of pazopanib in patients with surgically unresectable or metastatic chondrosarcoma

BACKGROUND

This single-arm, multicenter, phase 2 study evaluated the safety and antitumor activity of pazopanib in patients with unresectable or metastatic conventional chondrosarcoma.

METHODS

Eligible patients had conventional chondrosarcoma of any grade with measurable tumors that were unresectable or metastatic. Patients with mesenchymal, dedifferentiated, and extraskeletal myxoid chondrosarcoma subtypes and patients who received prior tyrosine kinase inhibitor therapy were excluded. Pazopanib at 800 mg once daily was administered for 28-day cycles. Tumor responses were evaluated by local radiology assessments every 2 cycles. The primary endpoint was the disease control rate (DCR) at week 16 (4 cycles).

RESULTS

Forty-seven patients were enrolled. The DCR at 16 weeks was 43% (95% confidence interval [CI], 28%-58%), which was superior to the null hypothesis rate of 30%, but the 2-sided P value (exact test) was .09 (1-sided P = .045). One patient had a partial response. The median overall survival was 17.6 months (95% CI, 11.3-35.0 months), and the median progression-free survival was 7.9 months (95% CI, 3.7-12.6 months). Grade 3 or higher adverse events were infrequent; hypertension (26%) and elevated alanine aminotransferase (9%) were most common.

CONCLUSIONS

This study provides evidence of positive drug activity for pazopanib in conventional chondrosarcoma.

Chondrosarcoma: biology, genetics, and epigenetics

Chondrosarcomas constitute a heterogeneous group of primary bone cancers characterized by hyaline cartilaginous neoplastic tissue. They are the second most common primary bone malignancy. The vast majority of chondrosarcomas are conventional chondrosarcomas, and most conventional chondrosarcomas are low- to intermediate-grade tumors (grade 1 or 2) which have indolent clinical behavior and low metastatic potential. Recurrence augurs a poor prognosis, as conventional chondrosarcomas are both radiation and chemotherapy resistant. Recent discoveries in the biology, genetics, and epigenetics of conventional chondrosarcomas have significantly advanced our understanding of the pathobiology of these tumors and offer insight into potential therapeutic targets.

Imaging of Malignant Primitive Tumors of the Spine

Primary malignant tumors of the spine are rare and mainly include chordoma, chondrosarcoma, Ewing sarcoma or primitive neuroectodermal tumor, and osteosarcoma. The final diagnosis is based on the combination of patient age, topographic and histologic features of the tumor, and lesion pattern on computed tomography (CT) and magnetic resonance (MR) imaging. Imaging evaluation includes radiography, CT, bone scintigraphy, and MR imaging. CT is more useful than radiography for evaluating location of the lesion and analyzing bone destruction and matrix, whereas MR has unmatched ability to assess soft tissue extension. This pictorial review provides an overview of the most prevalent primitive malignant tumors of spine.

Intralesional vs. extralesional procedures for low-grade central chondrosarcoma: a systematic review of the literature

INTRODUCTION

Chondroid lesions are very common bone tumors. In most cases, they are benign enchondromas (EC) and, in a minor percentage, chondrosarcomas (CSs), the malignant counterpart. In the latter cases, surgery is the mainstay treatment, because they are chemo- and radio-resistant unless dedifferentiation occurs. If resection is recognized as the gold standard for intermediate-, high-grade tumors, and for low-grade chondrosarcoma (LG-CS) located in the spine and pelvis to reduce the risk of local recurrence, there is still no consensus in literature on the treatment of central low-grade chondrosarcoma (cLG-CS) located in the limbs. Our aim is to perform a review of literature on evidence supporting this approach or not.

MATERIALS AND METHODS

An electronic research of the medical archives was carried out in March 2017 seeking papers evaluating the results of curettage and resection in cLG-CS.

RESULTS

We selected 13 studies corresponding to our criteria. Unfortunately, they were descriptive, retrospective, non-randomized studies. We identified a population of 471 patients for a total of 473 low-grade chondrosarcomas. Two hundred and ninety-nine lesions were treated with curettage and 174 with wide surgery. The two groups were not homogeneous for diagnosis, size and staging, so no comparison between resection and curettage was possible. The global weighted average percentage of local recurrence was 6.7% (20 cases) and 10.9% (19 cases) after curettage and resection, respectively. No cases of metastasis were reported in the group treated with intralesional surgery, compared to five cases reported in the group treated with resection. Indications for surgery were given in most cases based on symptoms and imaging.

CONCLUSIONS

The absence of a preoperative histological diagnosis and the lack of a scientific method to conduct the studies do not sufficiently support curettage for low-grade chondrosarcomas. In the absence of this, resection must be considered a general rule for every malignancy. In our opinion, based on the low biological growth rate of low-grade chondrosarcoma, every chondromatous lesion can be followed-up. Biopsies must be performed based on clinical and radiological suspicions such as pain, scalloping or increase in size, rather than on performing a PET scan to evidence more informative high metabolic areas.

GABAB receptor regulates proliferation in the high-grade chondrosarcoma cell line OUMS-27 via apoptotic pathways

BACKGROUND

High-grade chondrosarcoma, which has a high incidence of local recurrence and pulmonary metastasis despite surgical resection, is associated with poor prognosis. Therefore, new and effective adjuvant therapies are urgently required for this disease. Gamma-aminobutyric acid (GABA), which acts as a neurotrophic factor during nervous system development, is related to the proliferation and migration of certain cancer cells. The GABAergic system, which is composed of GABA, the GABA-synthesizing enzyme glutamic acid decarboxylase (GAD), and GABA receptors, has an important function in nerve growth and development of neural crest. Therefore, the GABAergic system may play important functional roles in the proliferation of chondrosarcoma cells, which are derived from neural crest cells. We examined the anti-tumor effects of the GABAergic system on a chondrosarcoma cell line.

METHODS

We evaluated the underlying mechanisms of the anti-tumor effects of the GABAergic system, such as the involvement of different signaling pathways, apoptosis, and cell cycle arrest, in the high-grade chondrosarcoma cell line OUMS-27. In addition, we performed whole-cell patch-clamp recordings for Ca²⁺ currents and evaluated the changes in intracellular Ca²⁺ concentration via Ca²⁺ channels, which are related to the GABA_B receptor in high-grade chondrosarcoma cells.

RESULTS

The GABA_B receptor antagonist CGP had anti-tumor effects on high-grade chondrosarcoma cells in a dose-dependent manner. The activities of caspase 3 and caspase 9 were significantly elevated in CGP-treated cells compared to in untreated cells. The activity of caspase 8 did not differ significantly between untreated cells and CGP-treated cells. However, caspase 8 tended to be up-regulated in CGP-treated cells. The GABA_B receptor antagonist exhibited anti-tumor effects at the G1/S cell cycle checkpoint and induced apoptosis via dual inhibition of the PI3/Akt/mTOR and MAPK signaling pathways. Furthermore, the changes in intracellular Ca²⁺ via GABA_B receptor-related Ca²⁺ channels inhibited the proliferation of high-grade chondrosarcoma cells by inducing and modulating apoptotic pathways.

CONCLUSIONS

The GABA_B receptor antagonist may improve the prognosis of high-grade chondrosarcoma by exerting anti-tumor effects via different signaling pathways, apoptosis, cell cycle arrest, and Ca²⁺ channels in high-grade chondrosarcoma cells.

Falcine Myxoid Chondrosarcoma: A Rare Aggressive Case

Chondrosarcoma is the second most common primary malignancy of bone after osteosarcoma. Cranial primary chondrosarcomas mostly originate from the skull base cartilage formation zones. Parasagittal falcine origin is very rare for primary extra-skeletal intracranial chondrosarcomas. We report a rare case of primary myxoid chondrosarcoma at falx cerebri. The patient was a 35-year-old lady with right arm and leg weakness. Her brain magnetic resonance imaging depicted a left parasagittal mass lesion attached to the falx cerebri. En bloc resection via left frontal craniotomy was performed. Three more local recurrences occurred in 9 months’ time since the index surgery, which were all managed with re-surgeries and/or adjuvant stereotactic radiosurgeries. This is the second case of myxoid type parasagittal chondrosarcoma but with the most protracted disease course. Even though surgery remains the mainstay of treatment for parasagittal chondrosarcomas, adjuvant therapy might be necessary in aggressive ones.

Synergistic anti-proliferative effects of mTOR and MEK inhibitors in high-grade chondrosarcoma cell line OUMS-27

Chondrosarcoma is a malignant bone tumor that produces cartilaginous neoplastic tissue. Owing to the absence of an effective adjuvant therapy, high-grade chondrosarcoma has a poor prognosis. Therefore, it is important to develop an effective adjuvant therapy to prevent the recurrence and metastasis. Mammalian target of rapamycin (mTOR), a central regulator of cell growth, metabolism, proliferation, and survival, is considered an important target for anticancer drug development. The mitogen activated protein kinase (MAPK) pathway is another highly implicated cellular pathway in cancer and is thought to have compensatory effects in response to the inhibition of the phosphatidylinositol-3-kinase (PI3K)/Akt/mTOR signaling pathway. We investigated the mechanism of anti-proliferative effect of the mTOR inhibitor rapamycin and MAPK/ERK (MEK) inhibitor PD 0325901, and the combined effect of rapamycin and PD 0325901 on human chondrosarcoma cell line (OUMS-27). Combination therapy with rapamycin and PD 0325901 showed a stronger anti-proliferative effect on OUMS-27 cells than rapamycin monotherapy. We confirmed that the dual inhibition of the PI3K/Akt/mTOR and RAF/MEK/ERK signaling pathways had synergistic anti-proliferative effects in OUMS-27. Our results suggest that combination therapy of mTOR and MEK inhibitor could be an effective therapeutic approach against chondrosarcoma.

Centrosome amplification in chondrosarcomas: A primary cell culture and cryopreserved tumor sample study

The genetics background underlying the aggressiveness of chondrosarcoma (CS) is poorly understood. One possible cause of malignant transformation is chromosomal instability, which involves an error in mitotic segregation due to numerical and/or functional abnormalities of centrosomes. The present study aimed to evaluate centrosome amplification in cryopreserved samples of tumor tissue from patients with CS. An analysis was performed on 3 primary cultures of tumors from patients who underwent surgery between January 2012 and December 2012 at the Department of Orthopedics at the Barretos Cancer Hospital (Barretos, Brazil). Additionally, cryopreserved tumor specimens were analyzed from 10 patients. The data were assessed using immunocytochemistry and immunohistochemistry staining techniques with monoclonal antibody anti-γ-tubulin. A total of 4 samples of CS cultured cells were obtained from 3 patients. A recurrence of a histological grade III tumor was detected in a female patient with Ollier's syndrome. The other 2 cases were grade I and III. The incidence of centrosome amplification in the primary cultures ranged from 15-64% of the cells. Whereas control cultured fibroblasts showed baseline levels of 4% amplified cells. For the cryopreserved specimens, two independent observers analyzed each sample and counted the cells stained with γ-tubulin, verifying the percentage of affected cells to be a mean of 14%, with the number of clusters ranging between 0-6 per slide. In conclusion, centrosome amplification was found to be a consistent biological feature of CS and may underlie chromosomal instability in this tumor.

Magnetic resonance imaging, treatment and outcome of canine vertebral chondrosarcomas. Six cases

OBJECTIVES

To report the clinical presentation, magnetic resonance imaging features, treatments and outcomes of canine vertebral chondrosarcoma.

MATERIALS AND METHODS

Retrospective review of medical records of dogs with confirmed vertebral chondrosarcoma and magnetic resonance imaging of the lesions, from four different veterinary referral institutions.

RESULTS

A total of six dogs were included in this report. In all cases, magnetic resonance imaging revealed a lobulated mass involving the dorsal vertebral compartment, markedly hyperintense with few foci of hypointensity on T2-weighted images, iso to hypointense on T1-weighted images with contrast enhancement after gadolinium administration. Intralesional surgical resection was performed in three dogs and medical management in one, two dogs were euthanased and all lesions were submitted for histopathology. Magnetic resonance imaging findings correlated with histological findings of a low tumour grade. Rapid clinical improvement was noted after surgery but two of three dogs had local regrowth.

CLINICAL SIGNIFICANCE

Chondrosarcomas show local aggressiveness and resistance to conventional radiotherapy and chemotherapy, and so prognosis depends on feasibility of en bloc resection. Magnetic resonance imaging may be helpful in establishing a presumptive diagnosis and prognosis based on the feasibility of surgical resection.

Do Patients After Chondrosarcoma Treatment Have Age-appropriate Bone Mineral Density in the Long Term?

BACKGROUND

In long-term survivors of osteosarcoma and Ewing sarcoma treated with the addition of radio- and chemotherapy, low bone mineral density (BMD) and fractures have been observed, presumably resulting from these adjuvants. Because patients with chondrosarcoma usually are not treated with conventional adjuvant treatment, observation of low BMD in patients with chondrosarcoma presumably would be the result of other mechanisms. However, BMD in patients with a history of chondrosarcoma has not been well characterized.

QUESTIONS/PURPOSES

The aim of our study was to address the following questions: (1) Do long-term survivors of chondrosarcoma have normal BMD and, if not, which factors contribute to low BMD? (2) Is there a greater risk of fracture and does the Fracture Risk Assessment Tool (FRAX(®)) score reflect fracture likelihood?

METHODS

All known patients with a history of chondrosarcoma treated at our institution before 2006 were identified. Of 127 patients believed to be alive at the time of this study, 30 agreed to participate in this study (11 females, 19 males; mean age at surgery, 39 ± 12 years; mean followup, 12 ± 5 years). With the data available, the 30 participants were not different from the 97 nonparticipants in terms of age, sex, BMI, tumor grade, tumor location (axial versus appendicular, lower extremity versus elsewhere), and use of any treatment known to influence osteopenia (chemotherapy, lower extremity surgery). BMD was measured and history of fractures was assessed using a questionnaire. The patients´ BMD measurements in this study were sex- and age-matched with a normative sex- and age-categorized reference population reported by Kudlacek et al. Associations were tested by univariate regressions and ANOVAs of all measures of BMD and eligible oncologic and demographic factors.

RESULTS

Eighteen of 30 (60%) patients had a pathologic BMD according to the WHO dual-energy x-ray absorptiometry definition, 15 (50%) had osteopenia, and three (10%) had osteoporosis. T-scores in the study cohort were lower than reference values for the femur neck (mean difference, 0.64; 95% CI, 0.27-1.01; p < 0.0015), but not for the spine (mean difference, 0.39; 95% CI, -0.06 to 0.84; p = 0.09). Thirteen patients (45%) reported a history of fractures not distinguishing between low and high impact. The incidence of fractures was 2.8 greater than expected from a comparison with a published microcensus survey of the Austrian population. No effect of the FRAX(®) score on fracture risk could be identified (p = 0.057).

CONCLUSIONS

Long-term survivors of chondrosarcoma appear to be at greater risk for having low BMD develop than the healthy population. Although these results are preliminary and based on a very small sampling of patients, if they can be confirmed in larger studies, BMD assessment by dual-energy x-ray absorptiometry might be considered as these patients are followed posttreatment by sarcoma care units. The reasons for low BMD still must be elucidated.

LEVEL OF EVIDENCE

Level IV, prognostic study.

The Investigation of ADAMTS16 in Insulin-Induced Human Chondrosarcoma Cells

OBJECTIVES

A disintegrin-like metalloproteinase with thrombospondin motifs (ADAMTS) is a group of proteins that have enzymatic activity secreted by cells to the outside extracellular matrix. Insulin induces proteoglycan biosynthesis in chondrosarcoma chondrocytes. The purpose of the present in vitro study is to assess the time course effects of insulin on ADAMTS16 expression in OUMS-27 (human chondrosarcoma) cell line to examine whether insulin regulates ADAMTS16 expression as well as proteoglycan biosynthesis with multifaceted properties or not.

METHODS

Chondrosarcoma cells were cultured in Dulbecco's modified Eagle's medium having either 10 μg/mL insulin or not. While the experiment was going on, the medium containing insulin had been changed every other day. Cells were harvested at 1st, 3rd, 7th, and 11th days; subsequently, RNA and proteins were isolated in every experimental group according to their time interval. RNA expression of ADAMTS was estimated by quantitative real-time polymerase chain reaction (qRT-PCR) by using primers. Immunoreactive protein levels were encountered by the western blot protein detection technique by using proper anti-ADAMTS16 antibodies.

RESULTS

ADAMTS16 mRNA expression level of chondrosarcoma cells was found to be insignificantly decreased in chondrosarcoma cells induced by insulin detected by the qRT-PCR instrument. On the other hand, there was a gradual decrease in immune-reactant ADAMTS16 protein amount by the time course in insulin-treated cell groups when compared with control cells.

CONCLUSION

It has been suggested that insulin might possibly regulate ADAMTS16 levels/activities in OUMS-27 chondrosarcoma cells taking a role in extracellular matrix turnover.

Suppressed invasive and migratory behaviors of SW1353 chondrosarcoma cells through the regulation of Src, Rac1 GTPase, and MMP13

Chondrosarcoma is the second frequent type of primary bone cancer. In response to stress to the endoplasmic reticulum, activation of eIF2α-mediated signaling is reported to induce apoptosis. However, its effects on invasive and migratory behaviors of chondrosarcoma have not been understood. Focusing on potential roles of Src kinase, Rac1 GTPase, and MMP13, we investigated eIF2α-driven regulation of SW1353 chondrosarcoma cells. In particular, we employed two chemical agents (salubrinal, Sal; and guanabenz, Gu) that elevate the level of eIF2α phosphorylation. The result revealed that both Sal and Gu reduced invasion and motility of SW1353 chondrosarcoma cells in a dose dependent manner. Live imaging using a fluorescent resonance energy transfer (FRET) technique showed that Sal and Gu downregulated activities of Src kinase as well as Rac1 GTPase in an eIF2α dependent manner. RNA interference experiments supported an eIF2α-mediated regulatory network in the inhibitory role of Sal and Gu. Partial silencing of MMP13 also suppressed malignant phenotypes of SW1353 chondrosarcoma cells. However, MMP13 was not regulated via eIF2α since administration of Sal but not Gu reduced expression of MMP13. In summary, we demonstrate that eIF2α dependent and independent pathways regulate invasion and motility of SW1353 chondrosarcoma cells, and inactivation of Src, Rac1, and MMP13 by Sal could provide a potential adjuvant therapy for combating metastatic chondrosarcoma cells.

Vascular pattern in enchondroma and chondrosarcoma: clinical and immunohistologic study

INTRODUCTION

Although cartilaginous tumors have low microvascular density, vessels are important for the provision of nutrition so that the tumor can grow and generate metastasis. The aim of this study was to assess the value of the vascular pattern classification as a prognostic tool in chondrosarcomas (CSs) and its relation with vascular endothelial growth factor (VEGF) expression.

MATERIALS AND METHODS

This was a retrospective study of 21 enchondromas and 57 conventional CSs. Clinical data and outcome were retrieved from medical files. CSs histologic grades (on a scale of 1 to 3) were determined according to the World Health Organization classification. The vascular pattern (on a scale of A to C) was assessed through CD34, according to Kalinski. CD105 and VEGF were also evaluated.

RESULTS

Poor outcome was significantly associated with vascular pattern groups B and C. Higher vascular pattern were 6.5 times more frequent in moderate-grade and high-grade CSs than in grade 1 CS. On multivariate analysis, a clear correlation was found between VEGF overexpression and B/C vascular patterns. Only 18 (benign and malignant) tumors stained for CD105.

DISCUSSION

The results point to the use of the vascular pattern classification as a prognostic tool in CSs and to differentiate low-grade from moderate-grade/high-grade CSs. Vascular pattern might be also used to complement histologic grade, VEGF immunostaining, and microvascular density, for indicating a patient's prognosis. Low-grade CSs develop under low neoangiogenesis, which conforms to the slow growth rate of these tumors.

Falcine and parasagittal chondrosarcomas

Intracranial chondrosarcomas are primary cartilaginous neoplasms that represent 6% of all skull base tumors. Intracranial extraskeletal chondrosarcomas are more rare, often arising from the meninges at the falx, tentorium, or cerebral convexity. They are generally characterized as classical or mesenchymal, with the latter associated with worse outcomes. We present our institutional series of falcine and parasagittal chondrosarcomas along with a review of the literature. Although skull base chondrosarcomas pose significant challenges due to their invasive biology and proximity to vital brainstem structures and cranial nerves, intracranial extraskeletal chondrosarcomas are generally associated with a good prognosis. Our review of the literature identified 29 patients with falcine and parasagittal chondrosarcomas. There were six recurrences, five among patients with the mesenchymal subtype and one in a patient with the classical subtype. All deaths occurred in patients with the mesenchymal subtype. Management of skull base chondrosarcomas is controversial but extraskeletal intracranial tumors can generally be managed by surgical resection alone. Treatment should be tailored to the biology of the tumor, with radiation therapy reserved for patients with the mesenchymal subtype.

Functional profiling of receptor tyrosine kinases and downstream signaling in human chondrosarcomas identifies pathways for rational targeted therapy

PURPOSE

Chondrosarcomas are notoriously resistant to cytotoxic chemotherapeutic agents. We sought to identify critical signaling pathways that contribute to their survival and proliferation, and which may provide potential targets for rational therapeutic interventions.

EXPERIMENTAL DESIGN

Activation of receptor tyrosine kinases (RTK) was surveyed using phospho-RTK arrays. S6 phosphorylation and NRAS mutational status were examined in chondrosarcoma primary tumor tissues. siRNA or small-molecule inhibitors against RTKs or downstream signaling proteins were applied to chondrosarcoma cells and changes in biochemical signaling, cell cycle, and cell viability were determined. In vivo antitumor activity of BEZ235, a phosphoinositide 3-kinase (PI3K)/mTOR inhibitor, was evaluated in a chondrosarcoma xenograft model.

RESULTS

Several RTKs were identified as critical mediators of cell growth, but the RTK dependencies varied among cell lines. In exploration of downstream signaling pathways, strong S6 phosphorylation was found in 69% of conventional chondrosarcomas and 44% of dedifferentiated chondrosarcomas. Treatment with BEZ235 resulted in dramatic reduction in the growth of all chondrosarcoma cell lines. Tumor growth was similarly inhibited in a xenograft model of chondrosarcoma. In addition, chondrosarcoma cells with an NRAS mutation were sensitive to treatment with a mitogen-activated protein kinase/extracellular signal-regulated kinase kinase (MEK) inhibitor. Functional NRAS mutations were found in 12% of conventional central chondrosarcomas.

CONCLUSIONS

RTKs are commonly activated in chondrosarcoma, but because of their considerable heterogeneity, targeted inhibition of the PI3K/mTOR pathway represents a rational therapeutic strategy. Chondrosarcomas with NRAS mutations may benefit from treatment with MEK inhibitors.

Skull base chondrosarcoma: evidence-based treatment paradigms

Chondrosarcomas are indolent but invasive chondroid malignancies that can form in the skull base. Standard management of chondrosarcoma involves surgical resection and adjuvant radiation therapy. This review evaluates evidence from the literature to assess the importance of the surgical approach and extent of resection on outcomes for patients with skull base chondrosarcoma. Also evaluated is the ability of the multiple modalities of radiation therapy, such as conventional fractionated radiotherapy, proton beam, and stereotactic radiosurgery, to control tumor growth. Finally, emerging therapies for the treatment of skull-base chondrosarcoma are discussed.

Chondrosarcoma apoplexy in thoracic spine

Chondrosarcoma is a very uncommon malignant primary bone tumor, especially, it occurs extremely rare in the spine. A 52-year-old man was admitted to the emergency room with sudden paraplegia. Twelve hours prior to a paraplegic event, he visited an outpatient clinic with discomfort and tenderness around the medial border of the right scapular, and his neurologic status was absolutely intact. Magnetic resonance imaging showed a lobulated soft tissue mass from T3 to T5, which extended to the epidural space. Computed tomography scans showed soft tissue mass on the spinal posterior arch and osteolytic change of the adjacent bony structures. Emergent surgery was performed and the lesion was removed. Dark reddish blood and gel-like material were encountered around the dura and posterior arch during the operation. Multiple pulmonary nodules were found on a chest CT scan and a biopsy of one of them had been proven to be a metastasis of chondrosarcoma. The histologic examination showed dedifferentiated chondrosarcoma. The patient's neurologic deficit was improved slowly from ASIA A to ASIA D. Chondrosarcoma in the spine is extremely rare, even more with acute hemorrhage and sudden expansion into the epidural space. We named it chondrosarcoma apoplexy. We should consider the possibility of a hemorrhagic event when the patient's neurologic deficit worsens suddenly with spinal bone tumor.

Multivariate analysis of the prognosis of 37 chondrosarcoma patients

OBJECTIVE

The current study aimedto screen for possible factors which affect prognosis of chondrosarcoma.

METHODS

Thirty seven cases were selected and analyzed statistically. The patients received surgical treatment at our hospital between December 2005 and March 2008. All of them had complete follow-up data. The survival rates were calculated by univariate analysis using the Kaplan-Meier method and tested by Log-rank. χ2 or Fisher exact tests were carried out for the numeration data. The significant indexes after univariate analysis were then analyzed by multivariate analysis using COX regression model. Based on the literature, factors of gender, age, disease course, tumor location, Enneking grades, surgical approaches, distant metastasis and local recurrence were examined.

RESULTS

Univariate analysis showed that there were significant differences in Enneking grades, surgical approaches and distant metastasis related to the patients' 3-year survival rate after surgery (P<0.001). No significant difference was not found in gender, age, disease course, tumor location or local recurrence (P>0.05). Multivariate analysis showed that Enneking grade (P=0.007) and surgical approaches (P=0.010) were independent factors affecting the prognosis of chondrosarcoma, but distant metastasis was not (P=0.942).

CONCLUSION

Enneking grades, surgical approaches and distant metastasis are risk factors for prognosis of chondrosarcoma, among which the former two are independent factors.

Pediatric spinal tumors

Although tumors of the central nervous system in children constitute the second most prevalent tumor type of childhood, spinal cord tumors account for less than 10% of pediatric central nervous system tumors. The most common are intramedullary, although they can be found in the extradural compartment or as intradural extramedullary masses. Extradural tumors can arise from bony elements, the meninges, or soft tissues. Neuroblastomas and sarcomas are frequently encountered along with bone tumors. Intradural extramedullary tumors can be meningeal or from distant sites and include meningiomas and schwannomas; most tend to be benign. Intradural intramedullary tumors, neuronal or glial, can be derived from neuroepithelial tissues. For the intramedullary tumors, astrocytomas represent around 60% of tumors, ependymomas 30%, and developmental tumors 4%. Such tumors require a multidisciplinary approach to ensure optimal patient outcomes. Spinal cord tumors most often present with pain followed by motor regression, gait disturbance, sphincter dysfunction or sensory loss, torticollis, and kyphoscoliosis. Treatment is based on tumor type, but surgical resection is the mainstay. Predictors of outcome include the histological grading, extent of resection, and neurological status at the time of surgery.

Chondrosarcoma of the spinous process: a rare presentation

Chondrosarcomas are malignant cartilage forming tumours. They form the second most common primary malignant tumour involving the vertebral axis. We present a rare presentation of a secondary chondrosarcoma from the spinous process of lumbar vertebra and discussed its management. The main emphasis is on the rare presentation and the need for awareness and suspicion of the pathology.

Extraskeletal mesenchymal chondrosarcoma in the axillary region: reports of two cases

Extraskeletal mesenchymal chondrosarcomas (EMCs) are relatively uncommon, and a location in the upper extremity, especially in the shoulder or axillary region, is rare. Furthermore, the radiographic findings of EMCs do not show any features that distinguish them from other neoplasms, and therefore, definitive diagnoses are made based on histological features. EMC is an aggressive tumor with a poor prognosis, and requires wide surgical excision. However, its treatment may involve peculiarities such as a difficulty in obtaining a proper surgical margin in the axillary region or shoulder. In this report, the authors present two rare cases of EMCs in the axillary region.

Imaging of spine neoplasm

Although most often back pain is of benign origin, it can occasionally be a harbinger of a more serious spinal condition, including spine neoplasm. Knowledge of the typical clinical history of spinal tumors and an understanding of the innervation of the spine and surrounding supporting structures may allow us to better understand when to pursue advanced imaging in the evaluation of spinal pain syndromes. Many radiologists have divided the differential diagnosis of neoplasms of the spine into compartments. These compartments include the extradural compartment, intradural/extramedullary compartment, and the intramedullary compartment.

The diagnostic and prognostic value of ¹⁸F-FDG PET/CT in the initial assessment of high-grade bone and soft tissue sarcoma. A retrospective study of 89 patients

PURPOSE

To evaluate the feasibility of (18)F-FDG PET/CT for initial assessment in high-grade bone sarcomas (BS) and soft tissue sarcomas (STS).

METHODS

During the years 2001-2010, 89 patients (30 BS, 59 STS) referred for further evaluation and surgical treatment of a high-grade BS or STS also had a PET/CT scan performed for staging preoperatively (n = 68) or within 1 month of surgery (n = 21). Metastatic lesions suggested on the PET/CT scan were confirmed or rejected by histological evaluation, by additional imaging or by follow-up. In 68 patients (28 BS, 40 STS) the relationship between the maximal standardized uptake value (SUVmax) of the primary tumour and survival was examined.

RESULTS

The PET/CT scan suggested the presence of 13 metastatic lesions in BS patients (5 lymph node, 8 distant) and 21 metastatic lesions (6 lymph node, 15 distant) in STS patients. The calculated sensitivity (SE) and specificity (SP) were 95 % and 96 % for detection of distant metastases, and the predictive value (PV) of a positive or a negative test was 87 % and 98 %, respectively. SE and SP were 100 % and 90 % for detection of lymph node metastases, and the PV of a positive or a negative test was 27 % and 100 %, respectively. The 5-year survival was 81 % among patients with SUVmax below the median value (≤ 10), but was 33 % among those with SUVmax >10.

CONCLUSION

FDG PET/CT for the initial assessment of patients with high-grade BS or STS was feasible with high SE and SP, but in those with lymph node metastases the PV of a positive test was low. The SUVmax of the primary tumour was a strong prognostic factor for survival.

Clinical outcome of central conventional chondrosarcoma

INTRODUCTION

Aim of this study was to analyze (1) survival, local recurrence (LR), and metastasis rates between the three histological tumor grades; (2) whether type of treatment and tumor site influenced prognosis for each histologic grade.

METHODS

We retrospectively studied 296 patients with central conventional chondrosarcomas (CS) (87 grade 1, 162 grade 2, and 47 grade 3). The femur was the most common site (91 cases), followed by the pelvis (82) and other less frequent sites. Type of surgery was related with histologic grade. Margins were wide in 222 cases, marginal in 23, and intralesional in 51 cases.

RESULTS

At a mean of 7 years, 201 patients remained continuously NED, 33 were NED after treatment of relapse, 15 were AWD, 35 were died of disease, and 12 of other causes. Survival was 92% at 5 years and 84% at 10 years, significantly influenced by histological grading. In grade 3 CS, two factors influenced survival: type of surgery (resection vs. amputation, P = 0.051) and site (P = 0.039). The two significant factors lost their significance at multivariate analysis.

CONCLUSION

Central conventional CS with low/intermediate grade has a good prognosis, while high-grade tumors have poor outcome. Tumor relapses are strictly related with histologic grade.