Primary chondrosarcoma of long bones and limb girdles

Development and external validation of a machine learning model for prediction of survival in undifferentiated pleomorphic sarcoma

PURPOSE

Machine learning (ML) algorithms to predict cancer survival have recently been reported for a number of sarcoma subtypes, but none have investigated undifferentiated pleomorphic sarcoma (UPS). ML is a powerful tool that has the potential to better prognosticate UPS.

METHODS

The Surveillance, Epidemiology, and End Results (SEER) database was queried for cases of histologically confirmed undifferentiated pleomorphic sarcoma (UPS) (n = 665). Patient, tumor, and treatment characteristics were recorded, and ML models were developed to predict 1-, 3-, and 5-year survival. The best performing ML model was externally validated using an institutional cohort of UPS patients (n = 151).

RESULTS

All ML models performed best at the 1-year time point and worst at the 5-year time point. On internal validation within the SEER cohort, the best models had c-statistics of 0.67-0.69 at the 5-year time point. The Multi-Layer Perceptron Neural Network (MLP) model was the best performing model and used for external validation. Similarly, the MLP model performed best at 1-year and worst at 5-year on external validation with c-statistics of 0.85 and 0.81, respectively. The MLP model was well calibrated on external validation. The MLP model has been made publicly available at https://rachar.shinyapps.io/ups_app/ .

CONCLUSION

Machine learning models perform well for survival prediction in UPS, though this sarcoma subtype may be more difficult to prognosticate than other subtypes. Future studies are needed to further validate the machine learning approach for UPS prognostication.

Precise single column resection and reconstruction with femoral head plus total hip replacement for primary malignant peri-acetabulum tumors

To evaluate whether single acetabular column can be reserved and the effect of reconstruction with femoral head plus total hip replacement (THR) for primary malignant peri-acetabulum tumors. From 2007 to 2015, nineteen patients with primary malignant peri-acetabulum tumors were enrolled. All cases underwent single column resection with clear surgical margins. Ten of the 19 tumor's resections were assisted by computer navigation. Femoral heads were applied to reconstruct anterior or posterior column defects; THR was used for joint reconstruction. The surgical safety, oncologic outcome and prosthesis survivorship and function were evaluated by regular follow-up. The average follow-up period was 65.9 months. Surgical margins contained wide resection in 12 cases and marginal resection in 7 cases. One patient with Ewing's sarcoma died 14 months postoperative due to lung metastasis. One case with chondrosarcoma had recurrence. One prosthesis was removed due to infection. The average MusculoSkeletal Tumor Society (MSTS) function score was 83.7%. Due to the relative small number of cases, there was no significant difference in the recurrence rate and prosthesis failure rate between the navigation group and non-navigation group. Single column resection and reconstruction with femoral head autograft plus THR is an effective, safe method with less complication rate and better functional outcome for patients with peri-acetabular tumors.

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

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

Chondrosarcoma With Pulmonary Metastatic Calcifications: A Case Report and Review of the Literature

A chondrosarcoma with pulmonary metastatic calcifications is a rarely reported phenomenon. This report discusses chondrosarcomas and their clinical features, diagnosis, and treatment, using as an example the case of a 55-year-old female with a right pelvic chondrosarcoma that developed over 10 years. In the last two years, the patient had increasing pulmonary findings, including pulmonary nodules, ground glass opacities, and likely pulmonary metastatic calcifications. The objective of this report is to explore chondrosarcomas and their pattern of metastatic presentation, with the hope of improving recognition of the disease and streamlining treatment.

Clinico-Genomic Profiling of Conventional and Dedifferentiated Chondrosarcomas Reveals TP53 Mutation to Be Associated with Worse Outcomes

PURPOSE

Chondrosarcomas are the most common primary bone tumor in adults. Isocitrate dehydrogenase 1 (IDH1) and IDH2 mutations are prevalent. We aimed to assess the clinico-genomic properties of IDH mutant versus IDH wild-type (WT) chondrosarcomas as well as alterations in other genes.

EXPERIMENTAL DESIGN

We included 93 patients with conventional and dedifferentiated chondrosarcoma for which there were available clinical next-generation sequencing data. Clinical and genomic data were extracted and compared between IDH mutant and IDH WT chondrosarcomas and between TP53 mutant and TP53 WT chondrosarcomas.

RESULTS

IDH1 and IDH2 mutations are prevalent in chondrosarcoma (50.5%), more common in chondrosarcomas arising in the extremities, associated with higher age at diagnosis, and more common in dedifferentiated chondrosarcomas compared with grades 1-3 conventional chondrosarcoma. There was no difference in survival based on IDH mutation in univariate and multivariate analyses. TP53 mutation was the next most prevalent (41.9%) and is associated with worse overall survival and metastasis-free survival in both univariate and multivariate analyses. TP53 mutation was also associated with higher risk of recurrence following curative-intent surgery and worse survival among patients that presented with de novo metastatic disease.

CONCLUSIONS

IDH mutations are prevalent in chondrosarcoma though were not associated with survival outcomes in this cohort. TP53 mutations were the next most common alteration and were associated with worse outcomes.

Classification of Chondrosarcoma: From Characteristic to Challenging Imaging Findings

Chondrosarcomas can be classified into various forms according to the presence or absence of a precursor lesion, location, and histological subtype. The new 2020 World Health Organization (WHO) Classification of Tumors of Soft Tissue and Bone classifies chondrogenic bone tumors as benign, intermediate (locally aggressive), or malignant, and separates atypical cartilaginous tumors (ACTs) and chondrosarcoma grade 1 (CS1) as intermediate and malignant tumors. respectively. Furthermore, the classification categorizes chondrosarcomas (including ACT) into eight subtypes: central conventional (grade 1 vs. 2–3), secondary peripheral (grade 1 vs. 2–3), periosteal, dedifferentiated, mesenchymal, and clear cell chondrosarcoma. Most chondrosarcomas are the low-grade, primary central conventional type. The rarer subtypes include clear cell, mesenchymal, and dedifferentiated chondrosarcomas. Comprehensive analysis of the characteristic imaging findings can help differentiate various forms of chondrosarcomas. However, distinguishing low-grade chondrosarcomas from enchondromas or high-grade chondrosarcomas is radiologically and histopathologically challenging, even for experienced radiologists and pathologists.

The national incidence of chondrosarcoma of bone; a review

BACKGROUND

Chondrosarcoma (CS) epidemiology has been studied by a number of authors using national cancer registry cohorts. Many reports share the common findings of a slight increase in incidence, but not all. The patterns and causes for these changes are divergent while reflection concerning methodological challenges are often missing.

METHOD

We have performed a structured literature review to find national analyses of CS incidence published from 2010 to 2020. We included eight studies of national incidence of CS, summarise their findings and patterns of change. We further discuss explanations given for these changes to better understand the real patterns and raise awareness in their interpretation.

RESULTS

Reported crude incidence ranges from 0.27 per million per year overall in Saudi Arabia to 5.4 in the Netherlands. Four studies from the USA, England, Switzerland and France report age standardised rates of 2.0-4.1 per million per year overall. While some countries report stable patterns, most report a slight increase. The Netherlands is the only country reporting a large increase, driven by a 10-fold increase in the incidence of ACT/grade 1 CS during the study period. We challenge the explanations given for this and suggest that this most likely is a result of variable interpretation and definition of CS at the lower levels of disease aggressiveness. This should raise awareness to possible over-treatment of CS in the Netherlands.

CONCLUSION

The most likely national incidence of CS of bone is between 2-4 per million per year. Three modern reports present an incidence of 3.4-4.1 per million per year.

Bone abnormalities in the middle Anisian marine sauropsids from Winterswijk

While the occurrence of skeletal pathologies in Middle Triassic marine reptiles has been poorly documented until now, massive accumulations of bone remains from the Germanic Basin provide the opportunities for documentation. Herein, we describe skeletal abnormalities in the Middle Triassic bone material from the Vossenveld Formation of Winterswijk, the Netherlands. The aim of the study is to distinguish in the studied bones pathologies resulting from malady or trauma and taphonomic alterations. Furthermore, an attempt was made to assess on how the pathologies also represent paleoecological data. Our survey led to the identification of one broken and healed bone, one case of abnormal coossification, and one case of posttraumatic fibro-osseous dysplasia. While the latter two pathologies give little insight into the ecology and function of the affected animals, the fractured dentary is attributed to Nothosaurus marchicus, a common sauropterygian macropredator. It proves that the individual survived long enough to heal, despite the injury hampering its hunting potential. One abnormally shaped humerus is interpreted as postmortem taphonomic deformation, emphasizing the necessity of utilization of detailed diagnostics to distinguish actual paleopathologies from nonbiological distortion.

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

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

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

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

Appendicular dedifferentiated chondrosarcoma: A management and survival study from the SEER database

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Dedifferentiated chondrosarcoma is an aggressive bone tumor with high rates of metastasis that severely impact the patient’s prognosis.

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Treatment usually consists of either a limb-salvage procedure or limb amputation, the former being more commonly performed.

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Size of the tumor severely impacts the likelihood of presenting metastasis at diagnosis.

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Female gender appears to be an important protective factor against death.

Introduction

Dedifferentiated chondrosarcoma (DDC) is an aggressive osseous neoplasm with a dismal prognosis. Treatment commonly involves limb-salvage surgery or amputation. In patients with appendicular DDC, we sought to describe demographic, clinical and treatment characteristics (1), analyze risk factors for metastasis (2) and overall death (3), and assess survival rates by treatment (4).

Materials and methods

Two-hundred-and-five patients from the SEER Database were included in our analysis. Demographic, clinical and treatment variables were analyzed. Multivariate regression was performed to identify risk factors. Survival analysis was performed using the Kaplan-Meier method.

Results

Fifty-one (24.9 %) of the patients included presented metastasis at diagnosis. The most common locations were the lungs, other sites, and bone. Surgery to the primary site was more common in patients without metastasis (94.2 %) than those with (78.2 %); limb-salvage procedures were more common than amputations. Tumors >8 cm (T2) and those discontinuous (T3) were more likely to present metastasis at diagnosis (OR = 2.54, p = 0.043 and OR = 7.4, p = 0.008, respectively). Female gender was found to be a protective factor for overall death on crude analysis (OR = 0.33, p = 0.019). Metastases to sites other than the lungs (M1b) had the highest risk of overall death (OR = 49, p = 0.01). Combination of surgery and chemotherapy showed a trend towards higher overall survival in non-metastatic patients (p = 0.1069 and p = 0.1703).

Conclusions

Appendicular DDC displays a high metastatic rate and low survival rates. The most common procedure is a limb-salvage surgery. Tumor size increases the risk of presenting metastases at diagnosis and female gender is a protective factor against death.

The influence of site on the incidence and diagnosis of solitary central cartilage tumours of the femur. A 21st century perspective

OBJECTIVE

To determine the incidence of central cartilage tumours (CCTs) in the femur and the impact of site (proximal, mid and distal thirds) on tumour grade. To compare study results with historically published data.

MATERIALS AND METHODS

Retrospective review of solitary CCTs arising in the femur over the past 13 years. Data collected included location (proximal, mid and distal thirds) and final diagnosis in terms of tumour grade based on imaging features ± histology. Case material collected from three bone tumour textbooks provided historical data.

RESULTS

430 solitary CCTs were included in the femur. 73% cases arose in the distal, 3.7% in the mid and 23% in the proximal femur. The ratio of "benign" (combining enchondroma and atypical cartilaginous tumour (ACT)) to higher grade chondrosarcoma (CS) was 11:1 in the distal, 1:1 in the mid and 1:1.5 in the proximal femur, the distribution of benign to malignant tumours being significantly different between the regions (F test, p < 0.05). Comparison with historical data showed a reversal of the benign (enchondroma) to malignant (ACT and higher grade CS) of 30%:70%-84%:16% in the current series.

CONCLUSIONS

The site of origin of a CCT in the femur has an impact on final diagnosis with CS uncommon in the distal as compared with the mid and proximal femur. This is in contradistinction to historical data where the incidence of CS exceeded that of enchondroma at all sites.

Surgical Treatment of Bone Sarcoma

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

Clinical features and treatment outcomes of dedifferentiated and grade 3 chondrosarcoma: A multi-institutional study

Chondrosarcoma is the second most common primary malignant bone tumor. In this multicenter study, we sought to evaluate the (i) disease-specific survival (DSS) and disease-free survival (DFS), and (ii) prognostic factors in patients with dedifferentiated chondrosarcoma (DDCS) and grade 3 chondrosarcoma (G3CS) in Japan. We retrospectively investigated the treatment outcomes and prognostic factors in 62 patients with DDCS and 19 patients with G3CS at 15 institutions participating in the Japanese Musculoskeletal Oncology Group. We also clarified significant clinico-pathological factors for oncological outcomes. In surgery for primary lesions aimed at cure, a histologically negative margin (R0) was obtained in 93% (14/15) of patients with G3CS and 100% (49/49) of patients with DDCS. The 5-year DSS was 18.5% in patients with DDCS and 41.7% in patients with G3CS (P = 0.13). Local control was obtained in 80% (12/15) and 79.6% (39/49) of patients with G3CS and DDCS in the primary lesion after surgery with a wide surgical margin, respectively. In multivariate analysis, stage and no treatment/palliative treatment for the primary lesion were independent prognostic factors for DSS of DDCS, age and no treatment/palliative treatment for DSS of G3CS. The 5-year DFS rate was 22.8% in 26 patients with DDCS who did not receive adjuvant chemotherapy, and 21.4% in 14 patients who received adjuvant chemotherapy. The prognosis of DDCS remains poor, although R0 resection was performed in most cases. Effective and/or intensive chemotherapeutic regimens or agents should be considered or developed for patients with high-grade chondrosarcoma, particularly for those with DDCS.

Impact of tumour stage on the surgical outcomes of scapular chondrosarcoma

PURPOSE

Chondrosarcomas are common primary bone tumours in adults, often affecting the flat bones. Oncologic outcomes are often tied to tumour grade; however, grade is only a factor in the aggressiveness of a tumor. Extracompartmental extension, or tumor stage, has been found to be predictive of a poor outcome in other flat bone chondrosarcomas; however, this relationship has not been identified in the scapula. The purpose of the current study was to analyze the impact of tumour stage on the outcome of patients with scapular chondrosarcoma.

METHODS

Thirty-nine patients (26 males:13 females) with a mean age of 46 ± 17 undergoing surgical resection of a scapular chondrosarcomas were reviewed. Most patients had grade 1 (n = 24) tumors, with 26 (67%) having extracompartmental extension. The mean follow-up was eight years.

RESULTS

The ten year disease-specific survival was 77%. High-grade tumours (HR 18.15, p < 0.01) were associated with death due to disease. The ten year local recurrence- and metastatic-free survival were 77% and 74%. Positive surgical margins (HR 8.85, p < 0.01) were associated with local recurrence, and local recurrence was associated with metastatic disease (HR3.37, p = 0.04). All disease recurrences and death due to disease occurred in patients with extracompartmental extension (p < 0.05).

CONCLUSION

Extracompartmental extension was associated with a worse oncologic outcome in patients with scapular chondrosarcomas. Positive margins were associated with local recurrence, which was associated with metastatic disease; wide local excision with negative margins should be a goal for all patients, regardless of tumour grade.

Malignant Cartilage-Forming Tumors

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

An unusual etiology of bilateral pulmonary nodules: Another challenge of hide and seek

An elderly gentleman presented with bilateral pulmonary nodules found incidentally during the workup of acute pancreatitis. He did not have any respiratory or urogenital symptoms. A biopsy of the lung nodule revealed myxoid mesenchymal neoplasm of extraosseous origin. As the patient was asymptomatic, only the increased uptake in the penile shaft base on the whole-body PET-CT study yielded a diagnosis of primary penile chondrosarcoma after biopsy. A rare presentation of chondrosarcoma in an elderly gentleman highlighting the importance of obtaining a histopathological specimen, as the prognosis of metastatic diseases is widely variable.

The incidence and diagnostic relevance of pathological fracture in conventional central chondrosarcoma

OBJECTIVE

To determine the incidence and diagnostic relevance of pathological fracture in patients with conventional central chondrosarcoma (CC-CS).

MATERIALS AND METHODS

Retrospective review of patients with CC-CS diagnosed between January 2007 and December 2019. Data collected included age, sex, skeletal location and the presence of pathological fracture at presentation. Histological tumour grade based on surgical resection or needle biopsy was classified as atypical cartilaginous tumour (ACT)/grade 1 CS (ACT/Gd1 CS), high-grade CS (HG-CS) and dedifferentiated CS (DD-CS). The presence of pathological fracture was correlated with age, skeletal location and tumour grade.

RESULTS

Three hundred seventeen patients were included (177 males and 140 females with mean age 55.8 years, range 9-91 years). Mean age of patients without pathological fracture was 54.4 years and those with pathological fracture 62.9 years (p = 0.002). The major long bones were involved in 171 cases, the flat bones in 112 cases, the mobile spine in 7 cases and the small bones of the hands and feet in 27 cases. There were 81 ACT/Gd 1 CS, 168 HGCS and 68 DD-CS. Pathological fracture was evident at presentation in 51 (16.1%) cases, the commonest bones involved being the femur (n = 21; 41.2%), humerus (n = 10; 19.6%) and acetabulum (n = 7; 13.7%). Pathological facture occurred in 7 cases of ACT/Gd 1 CS (13.7%), 23 cases of HGCS (45.1%) and 21 cases of DD-CS (41.2%) (p = 0.001). Following multivariate analysis, both older age and histological grade were independently significant factors.

CONCLUSIONS

Pathological fracture was seen in 16.1% of patients with CC-CS. Pathological fractures in the femur, humerus and acetabulum very likely indicate higher tumour grade.

A Recurrent Synovial Osteochondromatosis of the Knee: A Case Report

We report a case of a farmer who presented with synovial osteochondromatosis of his right knee that mimicked a huge hardball. A synovial proliferative disease associated with metaplasia of cartilage resulting in sporadic multiple intra-articular and extra-articular loose bodies. Our focus is to report a rare case successfully operated which has an educational significance in clinical practice.

Comparison of reconstructive techniques after acetabular resection for pelvic chondrosarcoma

AIMS

Hip reconstruction after resection of a periacetabular chondrosarcoma is complex and associated with a high rate of complications. Previous reports have compared no reconstruction with historical techniques that are no longer used. The aim of this study was to compare the results of tantalum acetabular reconstruction to both historical techniques and no reconstruction.

METHODS

We reviewed 66 patients (45 males and 21 females) with a mean age of 53 years (24 to 81) who had undergone acetabular resection for chondrosarcoma. A total of 36 patients (54%) underwent acetabular reconstruction, most commonly with a saddle prosthesis (n = 13; 36%) or a tantalum total hip arthroplasty (THA) (n = 10; 28%). Mean follow-up was nine years (SD 4).

RESULTS

There was no difference in the mean age (p = 0.63), sex (p = 0.110), tumour volume (p = 0.646), or type of resection carried out (p > 0.05) between patients with and without reconstruction. Of the original 66 patients, 61 (92%) were ambulant at final follow-up. There was no difference in the proportion of patients who could walk in the reconstruction and 'no reconstruction' groups (p = 0.649). There was no difference in the mean Musculoskeletal Tumor Society (MSTS) score between patients who were reconstructed and those who were not (61% vs 56%; p = 0.378). Patients with a tantalum THA had a significantly (p = 0.015) higher mean MSTS score (78%) than those who were reconstructed with a saddle prosthesis (47%) or who had not been reconstructed (56%). Patients who had undergone reconstruction were more likely to have complications (81% vs 53%; p = 0.033).

CONCLUSION

Reconstruction after resection of the acetabulum is technically demanding. In selected cases, reconstruction is of benefit, especially when reconstruction is by tantalum THA; however, the follow-up for these patients remains mid-term. When not feasible, patients with no reconstruction have an acceptable functional outcome. Level of Evidence: Level III Therapeutic. Cite this article: Bone Joint J 2021;103-B(2):391-397.

Proximal Femur Chondrosarcoma Misdiagnosed as Hip Arthritis: A Case Report

CASE

A 60-year-old man presented with left hip pain, and a radiograph showed reduced joint space. During the surgical procedure for a total hip replacement, a proximal femur mass was identified and biopsy was subsequently interpreted as grade 2 chondrosarcoma. A wide resection was needed, but he developed local recurrence after 2 years and was treated with an external hemipelvectomy.

CONCLUSIONS

Chondrosarcoma does not always present with a classical clinical picture or imaging, and it can be misdiagnosed. Practitioners should be highly suspicious of malignant disease as a cause for hip pain even if there is no direct indication of a neoplasm such as chondrosarcoma.

Chondrosarcoma local recurrence in the Cancer Registry of Norway cohort (1990-2013): Patterns and impact

BACKGROUND

There appears to be an association between local recurrence (LR) and risk of metastasis and death in central conventional chondrosarcoma (CCCS) of bone, but this has not been quantified in modern cohorts at a subtype level.

METHODS

We identified nonmetastatic cases of CCCS (N = 180) from the Cancer Registry of Norway. We present prognostic analysis of LR accounting for immortal time bias by descriptive statistics and multivariable Cox models.

RESULTS

Of 40 LR, one case demonstrated upgrading while two dedifferentiation. LR was associated with increased risk of metastasis (hazard ratio [HR] = 4.1 [confidence interval, 1.5-10.7]) and death (HR = 9.3 [5.0-17.5]) overall. LR was associated with significant increased risk of metastasis for those with a soft tissue component, axial location, malignancy grade 2, but not atypical cartilaginous tumor's, appropriately treated curettage patients, intramedullary tumors, grade 1 histology, extremity location or "Oslo low risk" group status. We found an increased risk of death for all groups except for those treated by appropriate curettage or belonging to the "Oslo low risk" group. About 50% of LR CCCS were asymptomatic and revealed by routine follow-up.

CONCLUSIONS

Upgrading of LR for CCCS was a seldom event. LR was associated with significant increased risk of metastasis and death overall, but not for appropriately treated curettage patients or "Oslo low risk" status.

What Factors Are Associated with Treatment Outcomes of Japanese Patients with Clear Cell Chondrosarcoma?

BACKGROUND

Clear cell chondrosarcoma is an extremely rare chondrosarcoma subtype; thus, its treatment outcomes and associated factors have not been widely studied. Knowing more about it is potentially important because clear cell chondrosarcomas are often misdiagnosed as other benign lesions and subsequently treated and followed inappropriately.

QUESTIONS/PURPOSES

(1) What are the patient- and tumor-related characteristics of clear cell chondrosarcoma? (2) What proportion of patients with clear cell chondrosarcoma initially had a misdiagnosis or a misleading initial biopsy result? (3) What is the survivorship of patients with clear cell chondrosarcoma free from death, local recurrence, and distant metastasis, and what factors are associated with greater survivorship or a reduced risk of local recurrence?

METHODS

Between 1985 and 2018, 12 Japanese Musculoskeletal Oncology Group (JMOG) hospitals treated 42 patients with a diagnosis of clear cell chondrosarcoma. All 42 patients had complete medical records at a minimum of 1 year or death, and were included in this multicenter, retrospective, observational study. No patients were lost to follow-up within 5 years of treatment but four were lost to follow-up greater than 5 years after treatment because their physicians thought their follow-up was sufficient. Clinical data were collected by chart review. The median (range) follow-up period was 69 months (2 to 392). In general, when a possibly malignant bone tumor was found on imaging studies, the histological diagnosis was made by biopsy before initiating treatment. Once the diagnosis had been made, the patients were treated by surgery only, complete resection if technically possible, because chondrosarcomas are known to be resistant to chemotherapy and radiotherapy. Unresectable tumors were treated with particle-beam radiation therapy. When patients with chondrosarcoma were referred after unplanned surgical procedures with inadequate surgical margins, immediate additional wide resection was considered before local recurrence developed. This diagnostic and treatment strategy is common to all JMOG hospitals and did not change during the study period. Primary wide resection was performed in 79% (33 of 42) patients, additional wide resection after initial inadequate surgery in 12% (five of 42), curettage and bone grafting in 5% (two of 42) patients, and radiotherapy was administered to 5% (two of 42). Surgical margins among the 40 patients who underwent surgery at JMOG hospitals were no residual tumor in 93% (37 of 42) of patients, microscopic residual tumor in 2% (one of 42), and macroscopic residual tumor or state after curettage or intralesional excision in 5% (two of 42). The oncological endpoints of interest were 5- and 10- year overall survival, disease-free survival, survival free of local recurrence, and survival free of distant metastases; these were calculated using the Kaplan-Meier method and compared using the log-rank test. Risk ratios with their respective 95% confidence intervals (CIs) were estimated in a Cox regression model. The Bonferroni adjustment was used for multiple testing correction.

RESULTS

The sex distribution was 74% men and 26% women (31 and 11 of 42, respectively), with a mean age of 47 ± 17 years. Eighty one percent (34 of 42) of tumors occurred at the ends of long bones, and the proximal femur was the most common site accounting for 60% (25 of 42). The mean size of the primary tumors was 6.3 ± 2.7 cm. Definite pathologic fractures were present in 26% (10 of 42) and another 26% (10 of 42) had extraskeletal involvement. None had metastases at presentation. Twenty four percent (six of 25) tumors in the proximal femur were misdiagnosed as benign lesions and treated inadequately without biopsy. Twenty nine percent (10 of 35) patients had initial misdiagnoses by biopsy and core needle biopsies had a greater risk of resulting in inaccurate histological diagnoses. The study patients' 5- and 10-year overall survival rates were 89% (95% CI 74 to 96) and 89% (95% CI 74 to 96), respectively; 5- and 10- year disease-free survival rates 77% (95% CI 58 to 89) and 57% (95% CI 36 to 75), respectively; 5- and 10-year local recurrence-free survival rates 86% (95% CI 68 to 95) and 71% (95% CI 49 to 86), respectively; and 5- and 10-year distant metastasis-free survival rates 84% (95% CI 67 to 93) and 74% (95% CI 53 to 88), respectively. Notably, bone metastases (17%, seven of 42) were as common as pulmonary metastases (14%, six of 42); four patients developed both bone and pulmonary metastases. The difference between 10-year overall survival rates and 10-year disease-free survival indicated very late recurrence more than 5 years after the initial treatment. After controlling for multiple comparisons, the only factor we found that was associated with local recurrence-free survival was initial treatment (positive margin versus primary wide resection) (risk ratio 8.83 [95% CI 1.47 to 53.1]; p = 0.022 after the Bonferroni adjustment). Additional wide resection reduced the risk of local recurrence.

CONCLUSIONS

The femoral head was the most common location of clear cell chondrosarcoma and had a high risk of misdiagnosis as common benign lesions that resulted in initial inadequate surgery and a consequent high risk of local recurrence. Immediate additional wide resection should be considered in patients who had initial inadequate surgery to reduce the risk of local recurrence. Because clear cell chondrosarcoma can recur locally or distantly in the bones and lungs in the long term, patients should be informed of the risk of very late recurrence and the necessity of decades-long with surveillance for local recurrence and lung and bone metastases.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

Gigantic secondary pelvic chondrosarcomas treated with pelvic resection type I and III: A case report

•

Proper selection of patients, preoperative planning and wide surgical margins with reconstruction provides good local control and clinical outcomes following pelvic resection.

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Patient with huge tumor need large amount of blood transfusion and postoperative intensive care due to longer surgery time.

•

The surgical site infection is common complication after pelvic resection and can be managed with debridement and antibiotic therapy.

Introduction

Patients with osteochondromatosis have a higher risk of malignant transformation into secondary chondrosarcoma. Chondrosarcoma at the pelvic region tends to present late and therefore pose a significant challenge for orthopedic surgeons because of the large tumor size, local extension, and complex anatomy with proximity to major neurovascular structure, intestinal and urinary tract.

Presentation of case

A 44-year-old male presented the chief complaint of 15 years growing lumps on his left buttock and right groin, presenting with pain. Plain radiography revealed popcorn calcification at the left iliac wing and right superior pubic rami. Multiple exostoses were also visible. MRI showed a larger tumor diameter at the left iliac wing by 33 cm and right pubic rami by 13 cm. The histopathological result from the biopsy suggested low-grade chondrosarcoma.

Result

The patient underwent pelvic resection type I and III in two-stage surgery. About one month after the first surgery, there was a postoperative infection. Debridement and antibiotic therapy resulted in a desirable functional outcome with an MSTS score 27 and no local recurrence sign during a one-year follow-up.

Discussion

Low-grade chondrosarcomas are not sensitive to radiation and chemotherapy; wide surgical resection is the mainstay of treatment. Chondrosarcoma at the iliac wing can be treated by pelvic resection type I, and further reconstruction needed to prevent pelvic tilting. Chondrosarcoma at pubic rami can be treated by pelvic resection type III.

Conclusion

Proper patient selections, preoperative planning, and wide surgical margins with reconstruction provide desirable local control and clinical outcomes following pelvic resection.

Chondrosarcomas in adolescents: are they different?

The objective of this study was to evaluate the characteristics and oncologic outcomes of a single institution series of chondrosarcoma of pelvis and extremities in patients who were 21 years or younger. Between January 2006 and December 2016, we operated on 249 chondrosarcomas of the pelvis and extremities. Eleven (4%) of these were 21 years or younger. The mean age was 18 years (range 14-21 years). There were eight males and three females. Four occurred in the pelvis. The other sites were humerus (three) and one each in the scapula, clavicle, metatarsal and proximal femur. There were five primary chondrosarcomas and 6 (55%) secondary chondrosarcomas. After appropriate surgical excision, we had nine free margins and two margins were microscopically involved. None of the 11 patients received adjuvant chemotherapy or radiotherapy. One patient never followed up after surgery and another was lost to follow-up after 32 months. Eight were alive and one had died. All survivors had minimum follow-up of 2 years (range 26-106 months). There was one local recurrence. The overall and disease-free survival at 5 years for all patients was 89 %. There was no statistically significant difference in survival for primary chondrosarcomas compared to secondary chondrosarcomas (P = 0.061), or pelvic chondrosarcomas compared to other sites (P = 0.264). Chondrosarcomas in children and adolescents constitute <5% of all chondrosarcomas. Secondary chondrosarcomas constituted more than half the cases. Overall, outcomes in the young were no different from those in adults.

Chondrosarcoma of bone in children and adolescents

PURPOSE

Chondrosarcomas typically present in adults during the fifth to seventh decades and are rare in young patients. The biological behaviour and oncological outcomes may be different in children and adolescents.

METHODS

We retrospectively evaluated the outcomes of all patients with chondrosarcoma of bone who were younger than 18 years of age at the time of diagnosis and were treated at our centre between 1995 and 2018.

RESULTS

The 15 consecutive patients studied included nine male and six female cases, with a mean age at diagnosis of 13 years (7 to 17). The median follow-up was 117 months (30 to 277). The tumours were primary and secondary in ten and five patients, respectively. The tumours were central in 13 and surface in two patients. The tumour locations were the humerus in five, digits in five, femur in three, radius in one and pelvis in one patient. The histological grades were grade I in seven, grade II in seven and grade III in one patient. The surgical treatments were limb salvage in ten patients and ray amputation in five patients. The surgical margins were wide in eight, marginal in two and intralesional in five patients. All the patients were alive and continuously free of disease at the time of the last follow-up. No patient developed metastases or local recurrence.

CONCLUSION

Chondrosarcoma of bone in children and adolescent patients has a very good prognosis and is less aggressive compared with published outcomes in older patients.

LEVEL OF EVIDENCE

IV.

Non-Conventional Treatments for Conventional Chondrosarcoma

Chondrosarcomas are the most common malignant tumors of the cartilage, are seen predominantly in adults, and have varied clinical behavior. The majority of them affect the medullary canal of long bones and pelvic bones. The prognosis of chondrosarcoma is closely related to histological grading; however, the grading is subject to interobserver variability. Conventional chondrosarcomas are overall considered to be chemotherapy- and radiation-resistant, resulting in limited treatment options. The majority of advanced conventional chondrosarcomas are treated with chemotherapy without any survival benefit. Recent studies have evaluated molecular genetic findings which have improved the understanding of chondrosarcoma biology. Newer therapeutic targets are desperately needed. In this review article, we explore ongoing clinical trials evaluating novel ways of treating advanced conventional chondrosarcoma.

Navigation-assisted pelvic resections and reconstructions for periacetabular chondrosarcomas

OBJECTIVES

Survival in patients with chondrosarcomas has not improved over 40 years. Although emerging evidence has documented the efficacy of navigation-assisted surgery, the prognostic significance in chondrosarcomas remains unknown. We aimed to assess the clinical benefit of navigation-assisted surgery for pelvic chondrosarcomas involving the peri-acetabulum.

METHODS

We studied 50 patients who underwent limb-sparing surgery for periacetabular chondrosarcomas performed with navigation (n = 13) without it (n = 37) at a referral musculoskeletal oncology centre between 2000 and 2015.

RESULTS

The intralesional resection rates in the navigated and non-navigated groups were 8% (n = 1) and 19% (n = 7), respectively; all bone resection margins were clear in the navigated group. The 5-year cumulative incidence of local recurrence was 23% and 56% in the navigated and non-navigated groups, respectively (p = 0.035). There were no intra-operative complications related to use of navigation. There was a trend toward better functional outcomes in the navigated group (mean MSTS score, 67%) than the non-navigated group (mean MSTS score, 60%; p = 0.412). At a mean follow-up of 63 months, the 5-year disease-specific survival was 76% and 53% in the navigated and non-navigated group, respectively (p = 0.085), whilst the 5-year progression-free survival was 62% and 28% in the navigated and non-navigated group, respectively (p = 0.032).

CONCLUSION

This study confirmed improved local control and progression-free survival with the use of computer navigation in patients with limb-salvage surgery for periacetabular chondrosarcomas, although the advancement in other treatment modalities is required for improvement of disease-specific survival.

Primary thoracic chondrosarcoma with intra-abdominal extension in a renal transplant recipient: A case report

Primary thoracic bone tumors are relatively rare. The most common type is chondrosarcoma, accounting for up to 48% of all cases. Patients with primary thoracic bone tumors commonly present with atypical thoracic pain or a solitary palpable chest mass, which gradually develops over months to years. The bones most often affected are the ribs, scapula, costochondral junctions and the sternum. The present study presents a case of a 79 year old previous transplant recipient with a large intra-abdominally expanding chondrosarcoma originating from the left lower thoracic cage and associated vague abdomdinal symptoms. Early recognition and awareness of atypical presentations of this disease are important in to appropriately guide diagnostic evaluation and therapeutic procedures.

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.

Risk stratification for central conventional chondrosarcoma of bone: A novel system predicting risk of metastasis and death in the Cancer Registry of Norway cohort

BACKGROUND AND OBJECTIVES

Interobserver variability in histological grading of central conventional chondrosarcoma (CCCS) limits the quality of patient information and research progression. We aim to quantify known and new prognostic variables and propose a risk stratification model.

METHOD

We selected 149 cases from the Cancer Registry of Norway. Cox proportional hazard models were estimated. Based on these results a dichotomous risk classification was proposed and presented by Kaplan-Meier estimates for rates of local recurrence, metastasis, and disease-specific survival.

RESULTS

The influence of axial skeletal location (Hazard ratio [HR] = 19.06), a soft tissue component ≥1 cm (HR = 13.45), and histological grade 3 (HR = 16.46) are all significant in predicting the rate of metastasis. The creation of a variable combining axial skeletal location and a soft tissue component ≥1 cm strongly predicts the risk of metastasis (HR = 14.02; P < .001) and death (HR = 2.74; P = .030) at multivariate analysis, making the histological grade insignificant. Together with metastasis at diagnosis (HR = 285.65; P < .001), this forms the basis of our proposed risk stratification, producing a small high-risk group (39 cases with 33% risk of metastasis) and a large low-risk group (103 cases with 2% risk of metastasis) without a histological grade.

CONCLUSION

Axial skeletal location and a soft tissue component ≥1 cm combined divides a CCCS cohort into low- and high-risk groups without a histological grade.

Chondrosarcomas in children and adolescents

Chondrosarcomas in children and adolescents are uncommon and constitute < 5% of all chondrosarcomas. There are very few studies discussing extremity chondrosarcomas in young patients.

The pelvis is the most common site, followed by the proximal femur.

As cartilaginous tumours can be quite challenging to diagnose, it is best for these lesions to be discussed in a multidisciplinary meeting which includes a radiologist and a pathologist specializing in bone tumours.

Treatment principles are similar to those in adults, with adequate surgical excision respecting oncologic principles being the mainstay of treatment. Select extremity Grade I chondrosarcomas may be managed with extended intralesional curettage without increasing the risk for local recurrence or metastatic disease, but case selection is critical and should be based on clinical, imaging and histological characteristics.

Chondrosarcomas are resistant to chemotherapy and relatively radioresistant. For mesenchymal chondrosarcomas, there may be a role for chemotherapy, though data on this is limited.

Prognosis and rate of recurrence correlate directly to the adequacy of the surgical resection.

Chondrosarcomas in younger patients behave in a similar fashion to those in adults, and outcomes in the young are no different from those in adults.

Cite this article: EFORT Open Rev 2020;5:90-95. DOI: 10.1302/2058-5241.5.190052

Contribution of Raman Spectroscopy to Diagnosis and Grading of Chondrogenic Tumors

In the last decade, Raman Spectroscopy has demonstrated to be a label-free and non-destructive optical spectroscopy able to improve diagnostic accuracy in cancer diagnosis. This is because Raman spectroscopic measurements can reveal a deep molecular understanding of the biochemical changes in cancer tissues in comparison with non-cancer tissues. In this pilot study, we apply Raman spectroscopy imaging to the diagnosis and grading of chondrogenic tumors, including enchondroma and chondrosarcomas of increasing histologic grades. The investigation included the analysis of areas of 50×50 μm² to approximately 200×200 μm², respectively. Multivariate statistical analysis, based on unsupervised (Principal Analysis Components) and supervised (Linear Discriminant Analysis) methods, differentiated between the various tumor samples, between cells and extracellular matrix, and between collagen and non-collagenous components. The results dealt out basic biochemical information on tumor progression giving the possibility to grade with certainty the malignant cartilaginous tumors under investigation. The basic processes revealed by Raman Spectroscopy are the progressive degrading of collagen type-II components, the formation of calcifications and the cell proliferation in tissues ranging from enchondroma to chondrosarcomas. This study highlights that Raman spectroscopy is particularly effective when cartilaginous tumors need to be subjected to histopathological analysis.

Advancing patient age is associated with worse outcomes in low- and intermediate-grade primary chondrosarcoma of the pelvis

BACKGROUND

Conventional primary pelvic chondrosarcoma often presents as a low- or intermediate-grade tumor in older patients. Although this is the most common variant of pelvic chondrosarcoma, studies examining treatment outcomes are lacking. The purpose of this study was to evaluate patients with these tumors to determine their outcomes of treatment.

METHODS

Seventy-three patients (grade I [n = 19, 26%] and grade II [n = 54, 74%]) were reviewed including 55 (75%) males and 18 (25%) females, with a mean age of 51 (range, 17-81) years and follow-up of 9 ± 5 years.

RESULTS

The 10-year disease-specific survival was 71%. Grade II disease (hazard ratio [HR], 6.74; P = .04) and age ≥50 years (HR, 3.97; P = .02) was associated with death due to disease. The 10-year local recurrence- and metastatic-free survival were 79% and 72%. Of the patients with a local recurrence (n = 11), 7 (64%) recurred at a higher histological grade. Patient age ≥50 years was associated with local recurrence (HR, 10.03; P = .02) and metastatic disease (HR, 4.20; P = .02).

CONCLUSION

Advancing patient age was an independent risk factor for worse survival and disease recurrence. Tumors often recurred locally at a higher grade and as such wide local excision remains the treatment of choice for these tumors.

Is the IDH Mutation a Good Target for Chondrosarcoma Treatment?

Chondrosarcomas are rare cancers of bone that arise from the malignant transformation of cells of chondrocytic lineage. They are known to be resistant to systemic cytotoxic chemotherapy and radiotherapy. The mainstay of management of localised disease is en bloc surgical resection with curative intent. Metastatic chondrosarcoma has a dismal prognosis, and to date, there are no proven effective systemic therapies in the advanced setting. Genomic studies have demonstrated that 50 to 80% of chondrosarcomas harbour a mutation in either the IDH1 or IDH2 gene. IDH inhibitors are currently under investigation in clinical trials, after showing promising results in phase 1 studies in IDH mutated cancers. In chondrosarcoma, IDH mutations represent an attractive target, however, early results with IDH inhibitors in IDH mutated chondrosarcoma are modest and the final results of ongoing trials are eagerly awaited.

Total Sacrectomy for the Treatment of Advanced Pelvic Chondrosarcoma

Primary tumors of sacrum are rare. The most common malignant tumors are metastasis, and only 6% of all malignant tumors arise from the sacrum. Chondrosarcoma is the third most common primary bone malignancy following myeloma and osteosarcoma. Surgery is usually the most important therapeutic modality; the wide en bloc excision remains the treatment of choice. These technically demanding procedures require a multidisciplinary expert team (neurosurgery, surgical and orthopedic oncology, colorectal surgery, and plastic surgery) involvement. We present in this article a case of a 52-year-old man who presented less infrequent symptoms, and the diagnosis was made in a very advanced stage. The wide surgical excision of the mass was performed by two different anterior and posterior approaches in one stage. The free surgical margins were difficult to achieve because it presented a voluminous tumor with invasion of the rectum, bone, and sacral plexus, but the age, low histological grade, and extensive experience in extreme pelvic surgery of our multidisciplinary team allowed approaching the patient with debulking surgery en bloc, successfully. Total hospital stay was 20 days. The patient was discharged without any complications. At the 6-months' follow-up, the patient showed no local recurrence.

The immune landscape of chondrosarcoma reveals an immunosuppressive environment in the dedifferentiated subtypes and exposes CSFR1+ macrophages as a promising therapeutic target

Survival rate for Chondrosarcoma (CHS) is at a standstill, more effective treatments are urgently needed. Consequently, a better understanding of CHS biology and its immune environment is crucial to identify new prognostic factors and therapeutic targets. Here, we exhaustively describe the immune landscape of conventional and dedifferentiated CHS. Using IHC and molecular analyses (RT-qPCR), we mapped the expression of immune cell markers (CD3, CD8, CD68, CD163) and immune checkpoints (ICPs) from a cohort of 27 conventional and 49 dedifferentiated CHS. The impact of the density of tumor-infiltrating lymphocytes (TILs), tumor-associated macrophages (TAMs) and immune checkpoints (ICPs) on clinical outcome were analyzed. We reveal that TAMs are the main immune population in CHS. Focusing on dedifferentiated CHS, we found that immune infiltrate composition is correlated with patient outcome, a high CD68+/CD8+ ratio being an independent poor prognostic factor (p < 0.01), and high CD68+ levels being associated with the presence of metastases at diagnosis (p < 0.05). Among the ICPs evaluated, CSF1R, B7H3, SIRPA, TIM3 and LAG3 were expressed at the mRNA level in both CHS subtypes. Furthermore, PDL1 expression was confirmed by IHC exclusively in dedifferentiated CHS (42.6% of the patients) and CSF1R was expressed by TAMs in 89.7% of dedifferentiated CHS (vs 62.9% in conventional). Our results show that the immune infiltrate of CHS is mainly composed of immunosuppressive actors favoring tumor progression. Our results indicate that dedifferentiated CHS could be eligible for anti-PDL1 therapy and more importantly immunomodulation through CSF1R + macrophages could be a promising therapeutic approach for both CHS subtypes.

Clear cell chondrosarcoma is an underestimated tumor: Report of 7 cases and meta-analysis of the literature

Introduction

Clear cell chondrosarcoma (CCC) is a rare subtype of chondrosarcoma and it is commonly considered a low-grade tumor and less aggressive than atypical cartilaginous tumor (grade 1 central chondrosarcoma). However, the experience even of musculoskeletal tumor centres with this rare entity is limited. The aim of this study is to analyse our own treatment results and those of the literature regarding the therapy and outcome of this lesion.

Material and Methods

7 cases of CCC have been treated in our department between 2003 and 2015. Their follow-up data were collected retrospectively. 187 literature cases with histopathological and clinical characteristics were retrieved by means of a PubMed search with the key word “clear cell chondrosarcoma”. The data pertaining to treatment and follow up were extracted. We analysed the survival of patient and the risk factors for local recurrence (LR) as well as metastatic disease (MD).

Results

The mean age at the time of diagnosis was 40 years. Two thirds of the patients were male. The mean follow-up time was 109 months. To our surprise, there was a high rate of LR (30%) and of MD (20%) when compared to low-grade conventional chondrosarcomas. 15% of LR and 20% of metastatic disease were observed after more than 10 years follow-up. Uncommon locations of MD such as in the spine is a unique observation in chondrosarcomas and underlines the high aggressiveness of this tumor. 10-year overall survival was almost 80%, 10-years disease free survival 60%. Positive margins (p = 0.038) and metastases (p = 0.006) impaired the overall survival significantly. The rate of local recurrence was significantly dependent on resection margin (p < 0.001); however there was no correlation with the grade of differentiation of the tumor. The development of MD was affected by local recurrence (p = 0.006), but we could not detect a significant association with margin status (p = 0.184).

Conclusions

A wide resection is the advocated treatment option. Long term follow-up for at least 10 years is necessary in order to not overlook late LR or MD. This work demonstrates for the first time the apparent aggressiveness of the CCC.

Genomic Profiling Identifies Association of IDH1/IDH2 Mutation with Longer Relapse-Free and Metastasis-Free Survival in High-Grade Chondrosarcoma

PURPOSE

Chondrosarcomas are the second most common primary malignant bone tumors. Although histologic grade is the most important factor predicting the clinical outcome of chondrosarcoma, it is subject to interobserver variability. Isocitrate dehydrogenase 1 (IDH1) and IDH2 hotspot mutations were recently found to be frequently mutated in central chondrosarcomas. However, a few published articles have been controversial regarding the association between IDH1/IDH2 mutation status and clinical outcomes in chondrosarcomas.

EXPERIMENTAL DESIGN

We performed hotspot sequencing of IDH1 and IDH2 genes in 89 central chondrosarcomas and targeted next-generation sequencing in 54 of them, and then correlated the IDH1/IDH2 mutation status with the patient's clinical outcome.

RESULTS

Although no association was discovered between IDH mutation status and the patient's overall survival, IDH1/IDH2 mutation was found to be associated with longer relapse-free and metastasis-free survival in high-grade chondrosarcomas. Genomic profiling reveals TERT gene amplification and ATRX mutation, for the first time, in addition to TERT promoter mutation in a subset (6/30, 20%) of high-grade and dedifferentiated chondrosarcomas. These abnormalities in telomere genes are concurrent with IDH1/IDH2 mutation and with CDKN2A/2B deletion or TP53 mutation, suggesting a possible association and synergy among these genes in chondrosarcoma progression. We found 21% of patients with chondrosarcoma also had histories of second malignancies unrelated to cartilaginous tumors, suggesting possible unknown genetic susceptibility to chondrosarcoma.

CONCLUSIONS

IDH1/IDH2 mutations are associated with longer relapse-free and metastasis-free survival in high-grade chondrosarcomas, and they tend to co-occur with TERT mutations and with CDKN2A/2B and TP53 alterations in a subset of high-grade chondrosarcomas.

Identifying the Prognosis Factors and Predicting the Survival Probability in Patients with Non-Metastatic Chondrosarcoma from the SEER Database

OBJECTIVE

To identify prognostic factors and establish nomograms for predicting overall survival (OS) and cause specific survival (CSS) of patients with non-metastatic chondrosarcoma.

METHODS

We collected information on patients with non-metastatic chondrosarcoma from the Surveillance, Epidemiology, and End Results (SEER) database between 2005 and 2014, together with data from the First Affiliated Hospital of Zhengzhou University from 2011 to 2016. Variables including patients' baseline demographics (age, race, and gender), tumor characteristics (tumor size and extension, histology subtype, primary site, and American Joint Committee on Cancer [AJCC] stage), therapy (surgery, chemotherapy, and radiotherapy), and socioeconomic status (SES) were extracted for further analysis. OS and CSS were retrieved as our researching endpoints. Patients from the database were regarded as the training set, and univariate analysis, Lasso regression and multivariate analysis as well as the random forest were used to explore the predictors and establish nomograms. To validate nomograms internally and externally, we applied bootstrapped validation internally with the training dataset, while the dataset for external validation was obtained from the First Affiliated Hospital of Zhengzhou University. We estimated the discriminative ability of nomograms based on Cox proportional hazard regression models by means of calibration curves and the concordance index (C-index) of internal and external validation.

RESULTS

After the implementation of exclusion criteria, there were 1267 patients in the training set and 72 patients in the testing set with non-metastatic chondrosarcomas. Age, gender, grade, histological subtype, primary site, surgery, radiation, chemotherapy, being employed/unemployed, tumor size, and tumor extension were significantly associated with prognosis in the univariate analysis. Age, gender, tumor size and extension, primary site, surgery, radiotherapy, chemotherapy, histological grade, and subtype were independent prognostic factors in the Cox models. The C-index of nomograms (internal: OS, 0.787; CSS, 0.821; external: OS, 0.777; CSS, 0.821) were higher than following conventional systems: AJCC sixth (OS, 0.640; CSS, 0.673) and seventh edition (OS, 0.675; CSS, 0.711).

CONCLUSIONS

Age, gender, tumor size and extension, surgery, histological grade, and subtype were independent prognostic factors for both OS and CSS. In addition, we revealed that chondrosarcomas in the trunk, radiotherapy, and chemotherapy were correlated with poor prognosis. Our nomograms based on significant clinicopathologic features can well predict the 3-year and 5-year survival probability of patients with non-metastatic chondrosarcoma and assist oncologists in making accurate survival evaluation.

Differential diagnosis and treatment of enchondromas and atypical cartilaginous tumours of the pelvis: analysis of 21 patients

INTRODUCTION

Studies focusing on enchondroma and atypical cartilaginous tumour (ACT) of the pelvis are lacking. The purpose of this study was to verify possible clinical and radiological findings with regard to distinguishing enchondromas from ACT of the pelvis. In addition, this study analysed functional and oncological outcomes in patients with enchondromas or ACT of the pelvis treated with curettage or resection.

MATERIALS AND METHODS

We retrospectively reviewed the medical records of 21 patients with confirmed enchondroma or ACT of the pelvis treated by curettage or resection from 1985 to 2018. The minimum follow-up was 18 months. The relationship between clinical and radiological factors and tumour type or local recurrence was assessed using Fisher exact test and Mann-Whitney U test.

RESULTS

Endosteal scalloping (p = 0.039), tumour size (0.005) and age (0.006) were shown to statistically favour ACT over enchondroma; by contrast, enchondroma and ACT patients had no difference in pain frequency (p = 0.5528). All patients with enchondroma had no local recurrence; in contrast, local recurrence occurred in one patient with ACT, initially treated with resection. The patient with local recurrence had a disease progression with a higher histological grade than the original tumour. Patients treated with curettage had better functional outcomes than patients treated with resection (p = 0.001).

DISCUSSION

Endosteal scalloping, tumour size and age could be helpful in the differential diagnosis between enchondroma and ACT of the pelvis. In addition, our study showed that ACT of the pelvis can be safely treated with curettage due to a low risk of local recurrence and better functional results compared with resection. In case of recurrence, we suggest to treat these patients with resection for the risk of disease progression.

Survival and prognostic factors in conventional G1 chondrosarcoma

Background

Chondrosarcoma is the second most frequent malignant bone tumor. Grade I chondrosarcoma (syn.: atypical cartilaginous tumor) is classified as an intermediately and locally aggressive neoplasm and typically is treated less aggressively (i.e., by intralesional curettage). Does the data regarding local recurrence (LR) and metastatic disease justify this?

Methods

From 1982 to 2014, 37 consecutive patients with G1 chondrosarcoma had been resected or curetted. The margin was defined as R0 (wide resection) or R1 (marginal resection). All patients were followed for evidence of local recurrence or metastatic disease. Overall and recurrence-free survival were calculated, and various potentially prognostic factors were evaluated.

Results

In 23 patients (62%), the tumor was widely (R0) resected, whereas in 14 patients, (38%) the resection was marginal (R1). Overall survival was 97% after 5 years, 92% after 10 years, and 67% after 20 years. Five-year local recurrence-free survival was 96%. Ten-year local recurrence-free survival was 83%. Local recurrence-free survival showed a significant correlation to margin status but no correlation to location or age. None of the patients with local recurrence died during the follow-up. One patient had metastatic disease at initial presentation, and a further five patients developed metastatic disease during follow-up. Metastatic disease proofed to be a highly significant factor for survival but was not correlated to local recurrence.

Conclusions

There was no significant correlation between the outcome and the primary tumor location. Marginal resection was a risk factor for LR, but there was no significant difference in the overall survival in patients with or without LR. Metastatic disease (16%) was more common than expected from the literature and a significant predictor for poor overall survival.

Has the Scottish Managed Clinical Network for Sarcoma influenced the survival outcomes for primary malignant bone tumours?

Primary malignant bone tumours (PMBT) are rare. We have reviewed patient outcomes in Scotland over a 20 year period and provided an update on the principles of current management strategies for the non-specialist practitioner. The Scottish Managed Clinical Network for Sarcoma (MCN) connects the three main management centres for sarcoma in Scotland: Glasgow, Aberdeen and Edinburgh. Prior to the formation of the MCN, all centres were connected via the Scottish Bone Tumour Registry (SBTR), where they would meet on a quarterly basis and all the bone/soft tissue tumour cases were discussed retrospectively. The MCN was introduced in 2006. Our primary aims were to assess the impact of the MCN on patient outcomes and to update clinicians on the recognition, assessment and staging of PMBT. A secondary aim was to compare results from the Scottish centres with other UK sites. The patient information was gathered from the Scottish Bone Tumour Registry, held at the Queen Elizabeth University Hospital in Glasgow. All patients with diagnoses of Osteosarcoma, Chondrosarcoma and Ewing Sarcoma between 1994 and 2014 were included. Results showed that there was no significant change in outcome following the formation of the Scottish Managed Clinical Network for Sarcoma, and that there were little differences in outcome amongst the three major management centres in Scotland. Findings also show Scotland to have similar outcomes to that of the rest of the UK following diagnosis of a primary malignant bone tumour.

Proximal humerus chondrosarcoma.Long-term clinical and oncological outcomes

INTRODUCTION

The proximal humerus is a common site for primary bone sarcomas, of which chondrosarcoma represents 15%. There are few reports about this select group of tumours. We set out to analyse a group of patients with proximal humerus chondrosarcoma treated with surgery and to assess their long term surgical and oncological outcomes.

MATERIAL AND METHODS

A retrospective review was performed and all patients with a proximal humerus chondrosarcoma treated with surgery were included in the study. Overall survival and local recurrence rates were analyzed. Post-operative complications were recorded and limb salvage surgery failures classified according to the Henderson classification.

RESULTS

37 patients were included in the study. The median age was 46 years (SD: 15.6, range: 17-24), 24 (65%) were female and the mean follow-up was 8.5 years (SD: 6.4, range: 2 -26). Eighteen patients were classified as grade 1 (49%), 15 as grade 2 (40%), 2 as grade 3 (5%) and 2 dedifferentiated chondrosarcomas (5%). The 10-year overall survival was 94.5% and the 10-year event-free survival was 84.5%. Five patients developed local recurrences (13%) and none of them was grade 1. The reconstruction failure rate was 27% at 5 years and 34% at 10 years. There were no complications or local recurrence in patients treated with curettage.

CONCLUSION

Proximal humerus chondrosarcoma presented high survival rates. Curettage and bone grafting is a safe procedure, with low risk of complications and local recurrence for grade 1 chondrosarcomas and should be the first indication for the proximal humerus. Reconstruction of the proximal humerus after a wide resection has a 5-year failure rate of 27% and 10-year failure rate of 34%.

Intralesional treatment versus wide resection for central low-grade chondrosarcoma of the long bones

BACKGROUND

Grade I or low-grade chondrosarcoma (LGCS) is a primary bone tumour with low malignant potential. Historically, it was treated by wide resection, since accurate pre-operative exclusion of more aggressive cancers can be challenging and under-treatment of a more aggressive cancer could negatively influence oncological outcomes. Intralesional surgery for LGCS has been advocated more often in the literature over the past few years. The potential advantages of less aggressive treatment are better functional outcome and lower complication rates although these need to be weighed against the potential for compromising survival outcomes.

OBJECTIVES

To assess the benefits and harms of intralesional treatment by curettage compared to wide resection for central low-grade chondrosarcoma (LGCS) of the long bones.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2018, Issue 4), MEDLINE and Embase up to April 2018. We extended the search to include trials registries, reference lists of relevant articles and review articles. We also searched 'related articles' of included studies suggested by PubMed.

SELECTION CRITERIA

In the absence of prospective randomised controlled trials (RCTs), we included retrospective comparative studies and case series that evaluated outcome of treatment of central LGCS of the long bones. The primary outcome was recurrence-free survival after a minimal follow-up of 24 months. Secondary outcomes were upgrading of tumour; functional outcome, as assessed by the Musculoskeletal Tumor Society (MSTS) score; and occurrence of complications.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures recognised by Cochrane. We conducted a systematic literature search using several databases and contacted corresponding authors, appraised the evidence using the ROBINS-I risk of bias tool and GRADE, and performed a meta-analysis. If data extraction was not possible, we included studies in a narrative summary.

MAIN RESULTS

We included 18 studies, although we were only able to extract participant data from 14 studies that included a total of 511 participants; 419 participants were managed by intralesional treatment and 92 underwent a wide resection. We were not able to extract participant data from four studies, including 270 participants, and so we included them as a narrative summary only. The evidence was at high risk of performance, detection and reporting bias.Meta-analysis of data from 238 participants across seven studies demonstrated little or no difference in recurrence-free survival after intralesional treatment versus wide resection for central LGCS in the long bones (risk ratio (RR) 0.98; 95% confidence interval (CI) 0.92 to 1.04; very low-certainty evidence). MSTS scores were probably better after intralesional surgery (mean score 93%) versus resection (mean score 78%) with a mean difference of 12.69 (95% CI 2.82 to 22.55; P value < 0.001; 3 studies; 72 participants; low-certainty evidence). Major complications across six studies (203 participants) were lower in cases treated by intralesional treatment (5/125 cases) compared to those treated by wide resection (18/78 cases), with RR 0.23 (95% CI 0.10 to 0.55; low-certainty evidence). In four people (0.5% of total participants) a high-grade (grade 2 or dedifferentiated) tumour was found after a local recurrence. Two participants were treated with second surgery with no evidence of disease at their final follow-up and two participants (0.26% of total participants) died due to disease. Kaplan-Meier analysis of data from 115 individual participants across four studies demonstrated 96% recurrence-free survival after a maximum follow-up of 300 months after resection versus 94% recurrence-free survival after a maximum follow-up of 251 months after intralesional treatment (P value = 0.58; very low-certainty evidence). Local recurrence or metastases were not reported after 41 months in either treatment group.

AUTHORS' CONCLUSIONS

Only evidence of low- and very low-certainty was available for this review according to the GRADE system. Included studies were all retrospective in nature and at high risk of selection and attrition bias. Therefore, we could not determine whether wide resection is superior to intralesional treatment in terms of event-free survival and recurrence rates. However, functional outcome and complication rates are probably better after intralesional surgery compared to wide resection, although this is low-certainty evidence, considering the large effect size. Nevertheless, recurrence-free survival was excellent in both groups and a prospective RCT comparing intralesional treatment versus wide resection may be challenging for both practical and ethical reasons. Future research could instead focus on less invasive treatment strategies for these tumours by identifying predictors that help to stratify participants for surgical intervention or close observation.