Aims. Our aim was to develop and validate nomograms that would predict the cumulative incidence of sarcoma-specific death (CISSD) and disease progression (CIDP) in patients with localized high-grade primary central and dedifferentiated chondrosarcoma. Methods. The study population consisted of 391 patients from two international sarcoma centres (development cohort) who had undergone definitive surgery for a localized high-grade (histological grade II or III) conventional primary central chondrosarcoma or dedifferentiated chondrosarcoma. Disease progression captured the first event of either metastasis or local recurrence. An independent cohort of 221 patients from three additional hospitals was used for external validation. Two nomograms were internally and externally validated for discrimination (c-index) and calibration plot. Results. In the development cohort, the CISSD at ten years was 32.9% (95% confidence interval (CI) 19.8% to 38.4%). Age at diagnosis, grade, and surgical margin were found to have significant effects on CISSD and CIDP in multivariate analyses. Maximum tumour diameter was also significantly associated with CISSD. In the development cohort, the c-indices for CISSD and CIDP at five years were 0.743 (95% CI 0.700 to 0.819) and 0.761 (95% CI 0.713 to 0.800), respectively. When applied to the validation cohort, the c-indices for CISSD and CIDP at five years were 0.839 (95% CI 0.763 to 0.916) and 0.749 (95% CI 0.672 to 0.825), respectively. The calibration plots for these two nomograms demonstrated good fit. Conclusion. Our nomograms performed well on internal and external validation and can be used to predict CISSD and CIDP after resection of localized high-grade conventional primary central and dedifferentiated chondrosarcomas. They provide a new tool with which clinicians can assess and advise individual patients about their prognosis. Cite this article: Bone Joint J 2020;102-B(12):1752–1759

Aims. Chondrosarcoma is the second most common primary sarcoma of bone: conventional chondrosarcoma accounts for 85% of all cases. Conventional chondrosarcoma may be central or peripheral. Most studies group central and peripheral chondrosarcomas together, although there is growing evidence that their clinical behaviour and prognosis differ. The aims of this study were to analyze any differences in characteristics between central and peripheral chondrosarcomas and to investigate the incidence and role of different syndromes. Methods. Data from two international tertiary referral sarcoma centres between January 1995 and December 2018 were retrospectively reviewed. The study population consisted of 714 patients with surgically treated conventional chondrosarcoma of the pelvis and limbs. Results. In patients with Ollier’s disease and Mafucci’s syndrome, 12/20 (60%) and 2/5 (60%) of malignancies, respectively, were in the limbs, most frequently in the proximal humerus, proximal tibia, and in the hands and feet. In patients with hereditary multiple exostosis (HME), 20/29 (69.0%) of chondrosarcomas were in the pelvis and scapula, specifically in the ilium in 13/29 (44.8%) and the scapula in 3/29 (10.3%). In central chondrosarcoma, survival of patients with Ollier’s disease and non-syndromic patients was the same (p = 0.805). In peripheral chondrosarcoma, survival among HME patients was similar (p = 0.676) in patients with tumours of the pelvis and limbs. Conclusion. Both central and peripheral chondrosarcoma have specific characteristics. HME is frequently seen in patients with a peripheral chondrosarcoma, in whom tumours are commonly located in the ilium and scapula. The incidence of Ollier’s disease is uncommon in patients with a central chondrosarcoma. Disease-specific survival is equal in different subtypes after adjustment for histological grade. The local recurrence-free survival is the same for different locations and subtypes after adjustment for surgical margin. Cite this article: Bone Joint J 2021;103-B(5):984–990

Aims. The preoperative grading of chondrosarcomas of bone that accurately predicts surgical management is difficult for surgeons, radiologists, and pathologists. There are often discrepancies in grade between the initial biopsy and the final histology. Recent advances in the use of imaging methods have shown promise in the ability to predict the final grade. The most important clinical distinction is between grade 1 chondrosarcomas, which are amenable to curettage, and resection-grade chondrosarcomas (grade 2 and 3) which require en bloc resection. The aim of this study was to evaluate the use of a Radiological Aggressiveness Score (RAS) to predict the grade of primary chondrosarcomas in long bones and thus to guide management. Methods. A total of 113 patients with a primary chondrosarcoma of a long bone presenting between January 2001 and December 2021 were identified on retrospective review of a single oncology centre’s prospectively collected database. The nine-parameter RAS included variables from radiographs and MRI scans. The best cut-off of parameters to predict the final grade of chondrosarcoma after resection was determined using a receiver operating characteristic curve (ROC), and this was correlated with the biopsy grade. Results. A RAS of ≥ four parameters was 97.9% sensitive and 90.5% specific in predicting resection-grade chondrosarcoma based on a ROC cut-off derived using the Youden index. Cronbach’s α of 0.897 was derived as the interclass correlation for scoring the lesions by four blinded reviewers who were surgeons. Concordance between resection-grade lesions predicted from the RAS and ROC cut-off with the final grade after resection was 96.46%. Concordance between the biopsy grade and the final grade was 63.8%. However, when the patients were analyzed based on surgical management, the initial biopsy was able to differentiate low-grade from resection-grade chondrosarcomas in 82.9% of biopsies. Conclusion. These findings suggest that the RAS is an accurate method for guiding the surgical management of patients with these tumours, particularly when the initial biopsy results are discordant with the clinical presentation. Cite this article: Bone Joint J 2023;105-B(7):808–814

Aim: The differential diagnosis between chondroma and grade I chondrosarcoma still represents a challenge. There are always cases in which a perfect diagnosis can’t be done for sure. This cases are defined in literature with different synonyms such as: borderline chondrosarcoma, grade 0 chondrosarcoma, atypical enchondroma or in situ chondrosarcoma. Enchondroma are benign lesions that do not require a surgical treatment. Low grade chondrosarcoma is a malignant tumour that can recur and also if in a low percentage of cases can metastasize. Methods: The Authors reviewed 22 cases of chondrosarcoma of the limbs for clinical, radiographycal and histological features. Results: Pain was present in 80% of cases of low grade chondrosarcoma, while was absent in enchondroma. Radiographic analysis was not significative. Bone scan was often positive in low grade chondrosarcoma as in enchondroma. Histology demonstrated a permeative pattern in chondrosarcoma with infiltration of the bone trabeculae. Conclusions: Only the complete evaluation of the patient resulted in a correct diagnosis. Follow-up of patients confirmed our findings

The February 2023 Oncology Roundup. 360. looks at: Is the number of national database research studies in musculoskeletal sarcoma increasing, and are these studies reliable?; Re-excision after unplanned excision of soft-tissue sarcoma is associated with high morbidity; Adjuvant radiation in atypical lipomatous tumours; The oncological outcomes of isolated limb perfusion and neoadjuvant radiotherapy in soft-tissue sarcoma patients - a nationwide multicentre study; Can low-grade chondrosarcoma be treated with intralesional curettage and cryotherapy?; Efficacy and safety of carbon ion radiotherapy for bone sarcomas: a systematic review and meta-analysis; Doxorubicin-polymeric meshes prevent local recurrence after sarcoma resection while avoiding cardiotoxicity; How important are skip lesions in Ewing’s sarcoma?; Improving outcomes for amputees: the health-related quality of life and cost utility analysis of osseointegration prosthetics in transfemoral amputees

Aims. The aim of this study was to report the outcomes of patients who underwent definitive surgery for secondary chondrosarcomas arising from osteochondromas. Patients and Methods. A total of 51 patients with secondary chondrosarcomas occurring from osteochondromas were reviewed. Median age was 36 years (interquartile range (IQR) 15 to 82). Median follow-up was 6.9 years (IQR 2.8 to 10.6). The pelvis was the most commonly affected site (59%). Histological grades were grade I in 35 (69%), grade II in 13 (25%), and grade III in three patients (6%). Results. Preoperative biopsy histology correctly predicted the final histological grade in 27% of patients. The ten-year disease-specific survival (DSS) for all patients was 89.4%. Local recurrence occurred in 15 patients (29%), more commonly in pelvic tumours (37%) compared with limb tumours (19%). Four patients with pelvic tumours died from progression of local recurrence. No patient with limb tumours died of disease. Wide/radical margin was associated with improved local recurrence-free survival (p = 0.032) and local recurrence was associated with worse DSS (p = 0.005). Conclusion. We recommend that a secondary chondrosarcoma arising from osteochondroma of the pelvis is resected with wide/radical resection margins. The balance between the morbidity of surgery and risk of local recurrence needs to be considered in patients with limb secondary chondrosarcomas. Cite this article: Bone Joint J 2019;101-B:1313–1320

Purpose. Extraskeletal chondrosarcoma is a rare tumor with an indolent course and high propensity for local recurrence and metastasis. This tumor most commonly presents in the proximal extremities of middle-aged males, and is commonly asymptomatic. Although slow growing, these tumors have a significant risk of eventual relapse and metastases, especially to the lung. There are no clinical trials that investigated the best treatment options for this tumor given its very low incidence. The aim of this study is to present the surgical and clinical results of extraskeletal chondrosarcoma, which is a rare tumor. Methods. In our clinic, the information of 13 patients who were diagnosed with extra-skeletal chondrosarcoma between 2006 and 2018 were retrospectively reviewed. Demographic information, tumor size, surgical treatments, chemotherapy and radiotherapy status, follow-up times, recurrence and metastases of the patients were recorded. Results. This study included 13 patients with an average age of 53.6 ± 15 (range, 28 to 73) years diagnosed with extraskelatal chondrosarcoma. In 8 of the patients, the tumor was located in the lower limbs and it was observed that the thigh was located mostly (46.2%). The mean follow-up period of the patients was 52.8 ± 19.9 (range, 24 to 96) months. All patients underwent extensive resection and only one patient had a positive surgical margin. In the follow-up, 5 (38.5%) of the patients developed recurrence, while 6 patients had lung metastasis (46.2%) and 53.8% (7 patients) of the patients exitus. The mean tumor size was 10.4 ± 3.2 (range, 5 to 17) cm. The median survival time of the patients in the study was 61 (50.5–71.4) months. The 5-year survival rate is 51.8%. There was no significant difference between survival times according to age, gender, side, limb location, postoperative RT, recurrence and presence of lung metastasis (log rank tests p > 0.05). The cut off value for exitus obtained by ROC analysis of tumor size was determined as 11 cm (fig 1). Accordingly, the survival time of patients with 11 cm and above tumor size was observed to be statistically significantly shorter. Conclusion. Consequently, ECM is a rare soft tissue sarcoma with high local recurrence and metastasis capacity. Therefore, close follow-up is recommended. The first option should be extensive resection. Studies with large patient series on the prognostic factors of the future ECM are needed. For any figures or tables, please contact the authors directly

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

Aims. The purpose of this study was to describe the effect of histological grade on disease-specific survival in patients with chondrosarcoma. Patients and Methods. A total of 343 patients with a chondrosarcoma were included. The histological grade was assessed on the initial biopsy and on the resection specimen. Where the histology showed a mixed grade, the highest grade was taken as the definitive grade. When only small focal areas showed higher grade, the final grade was considered as both. Results. The concordance between the highest preoperative biopsy grading and the highest final grading of the resection specimen in total was only 43% (146/343). In 102 specimens (30%), a small number of cells or focal areas of higher grade were observed in contrast to the main histology. The disease-specific survival, stratified according to the predominant histological grade, showed greater variation than when stratified according to the highest grade seen in the resection specimen. Conclusion. The diagnostic biopsy in chondrosarcoma is unreliable in assessing the definitive grade and the malignant potential of the tumour. When categorizing the grade of the resection specimen, the prognosis for local recurrence and disease-specific survival should be based on the highest grade seen, even when seen in only a few cells. Cite this article: Bone Joint J 2018;100-B:662–6

Aims. Few studies dealing with chondrosarcoma of the pelvis are currently available. Different data about the overall survival and prognostic factors have been published but without a detailed analysis of surgery-related complications. We aimed to analyse the outcome of a series of pelvic chondrosarcomas treated at a single institution, with particular attention to the prognostic factors. Based on a competing risk model, our objective was to identify risk factors for the development of complications. Patients and Methods. In a retrospective single-centre study, 58 chondrosarcomas (26 patients alive, 32 patients dead) of the pelvis were reviewed. The mean follow-up was 13 years (one week to 23.1 years). Results. A total of 26 patients (45%) were alive and 32 patients (55%) had died. Overall survival was 76%, 55% and 45% at one, five and ten years post-operatively, respectively. In a competing risk model the cumulative risk of the development of a surgery-related complication was 64% at six months and 69% at one year, post-operatively, respectively. Endoprosthetic reconstruction was a significant risk factor for the development of complications (p = 0.006). Complications were not significantly related to age or the location or grade of the tumour (p = 0.823, p = 0.976, p = 0.858). The development of complications did not have a negative effect on survival (p = 0.147). Conclusion. This is the first study with competing risk analysis of surgery-related complications in patients with a pelvic chondrosarcoma. The surgery in these patients remains prone to complications. Endoprosthetic reconstruction significantly increases the risk of the development of complications (p = 0.006). A competing risk model showed that the development of complications does not have a negative influence on overall survival (p = 0.147). An aggressive, surgical resection with the goal of achieving wide margins whenever possible remains the mainstay of treatment. . Cite this article: Bone Joint J 2017;99-B:686–96

Aims. Although chondrosarcomas (CSs) display true malignant features, including local recurrence (LR) and metastases, their behaviour in the hands and feet is thought to differ from that in other parts of the axial and appendicular skeleton by having a lower metastatic potential. The purpose of this study was to investigate the disease-specific and surgical factors that affect the local and systemic prognosis of CS of the hands and feet. Methods. A multicentre retrospective study was carried out at two tertiary sarcoma centres. A database search identified all patients with a CS treated between January 1995 and January 2018. There were 810 CSs of which 76 (9.4%) were located in the fingers, toes, metacarpals, and metatarsal bones. Results. The median age of the study population was 55 years (36 to 68) with a median follow-up of 52 months (22 to 87) months. Overall, 70% of the tumours were in the hand (n = 54) and 30% in the foot (n = 22). Predictors for LR were margin (p = 0.011), anatomical location (p = 0.017), and method of surgical management (p = 0.003). Anatomical location (p = 0.026), histological grade between 1 and 3 (p = 0.004) or 2 and 3 (p = 0.016), and surgical management (p = 0.001) were significant factors for LR-free survival. Disease-specific survival was affected by histological grade (p < 0.001), but not by LR (p = 0.397). Conclusion. Intralesional curettage of a low-grade CS is associated with an increased risk of LR, but LR does not affect disease-specific survival. Therefore, for low-grade CSs of the hands and feet, surgical management should aim to preserve function. In grade 2 CS, our study did not show any decreased disease-specific survival after recurrence; however, we suggest a more aggressive surgical approach to these tumours to prevent local recurrence, especially in the metacarpal and metatarsal bones. In high-grade tumours, the incidence of progressive disease is high and, therefore, the treatment of the primary tumour should be aggressive where possible, and patients observed closely for the development of metastatic disease. Cite this article: Bone Joint J 2021;103-B(3):562–568

Aims. The purpose of this study was to investigate the potential for achieving local and systemic control after local recurrence of a chondrosarcoma of bone. Patients and Methods. A total of 126 patients with local recurrence (LR) of chondrosarcoma (CS) of the pelvis or a limb bone were identified from a prospectively maintained database, between 1990 and 2015 at the Royal Orthopaedic Hospital, Birmingham, United Kingdom. There were 44 female patients (35%) and 82 male patients (65%) with a mean age at the time of LR of 56 years (13 to 96). The 126 patients represented 24.3% of the total number of patients with a primary CS (519) who had been treated during this period. Clinical data collected at the time of primary tumour and LR included the site (appendicular, extremity, or pelvis); primary and LR tumour size (in centimetres); type of operation at the time of primary or LR (limb-salvage or amputation); surgical margin achieved at resection of the primary tumour and the LR; grade of the primary tumour and the LR; gender; age; and oncological outcomes, including local recurrence-free survival and disease-specific survival. A minimum two years’ follow-up and complete histopathology records were available for all patients included in the study. Results. For patients without metastases prior to or at the time of local recurrence, the disease-specific survival after local recurrence was 62.5% and 45.5% at one and five years, respectively. After univariable analysis, significant factors predicting disease-specific survival were grade (p < 0.001) and surgical margin (p = 0.044). After multivariable analysis, grade, increasing age at the time of diagnosis of local recurrence, and a greater time interval from primary surgery to local recurrence were significant factors for disease-specific survival. A secondary local recurrence was seen in 26% of patients. Wide margins were a good predictor of local recurrence-free survival for subsequent recurrences after univariable analysis when compared with intralesional margins (p = 0.002) but marginal margins did not reach statistical significance when compared with intralesional margins (p = 0.084). Conclusion. In cases of local recurrence of a chondrosarcoma of bone, we have shown that if the tumour is non-metastatic at re-staging, an increase in disease-specific survival and in local recurrence-free survival is achievable, but only by resection of the local recurrence with a wide margin. Cite this article: Bone Joint J 2019;101-B:266–271

The aim of this study was to define the treatment criteria for patients with recurrent chondrosarcoma. We reviewed the data of 77 patients to examine the influence of factors such as the intention of treatment (curative/palliative), extent of surgery, resection margins, status of disease at the time of local recurrence and the grade of the tumour. A total of 70 patients underwent surgery for recurrent chondrosarcoma. In seven patients surgery was not a viable option. Metastatic disease occurred in 41 patients, appearing synchronously with the local recurrence in 56% of cases. For patients without metastasis at the time of local recurrence, the overall survival at a mean follow-up after recurrence of 67 months (0 to 289) was 74% (5 of 27) compared with 19% (13 of 50) for patients with metastasis at or before the development of the recurrence. Neither the type/extent of surgery, site of tumour, nor the resection margins for the recurrent tumour significantly influenced the overall survival. . With limited survival for patients with metastatic disease at the time of local recurrence (0% for patients with grade III and de-differentiated chondrosarcoma), palliative treatment, including local radiation therapy and debulking procedures, should be discussed with the patients to avoid long hospitalisation and functional deficits. For patients without metastasis at the time of local recurrence, the overall survival of 74% justifies an aggressive approach including wide resection margins and extensive reconstruction

Besides conventional chondrosarcoma, several rare chondrosarcoma subtypes are described, comprising about 15% of all chondrosarcomas. Clear cell chondrosarcoma (CCS) is a low-grade malignant tumour, often recurring after curettage, and showing overall survival of about 85%. Mesenchymal chondrosarcoma (MCS) is a highly malignant tumour occurring in bone and soft tissue of relatively young patients. The tumour shows differentiated cartilage mixed with undifferentiated small round cells. It often metastasises and shows a 5-year overall survival of 55%. Dedifferentiated chondrosarcoma (DDCS) is a tumour containing a high-grade non-cartilaginous sarcoma (DD), and a usually low-grade malignant cartilage-forming tumour (WD). The prognosis is poor. The lack of efficacious treatment of these rare tumours emphasises the need to learn more about their characteristics and to unravel potential targets for therapy. We constructed tissue microarrays (TMAs) with 2mm cores of 45 DDCS (WD and DD), 24 CCS, and 25 MCS, in triplicate. Using immunohistochemistry, we investigated protein expression of estrogen-signaling molecules, growth plate-signaling molecules, and other molecules which might be potential targets for therapy. In addition, we gathered genomic information using Agilent 44K oligo arrays. 30% of the WD components were positive for Cox-2. Almost all others were negative. For Bcl2, 88% of the small cells and 32% of the cartilage in MCS were positive. In CCS, WD, and DD 48%, 4%, and 12% were positive, respectively. We demonstrated the presence of ESR1 and aromatase protein in the majority of tumours in all subtypes. Using array CGH, we observed similar aberrations in the two components of DDCS, with additional aberrations in the DD. Celecoxib treatment is not recommended, as most of the tumours are negative for Cox-2. However, the presence of ESR1 and aromatase support a possible effect of anti-estrogen treatment in all subtypes, and application of Bcl2 inhibitors might chemosensitise MCS

Chondrosarcoma of the spine is a rare condition. In a 45-year follow-up study in one institution, only 21 cases were recorded. We report on three cases, one a secondary chondrosarcoma and two primary tumours. Two presented with hyper-calcaemic renal calculi following massive bone destruction, and one, which we observed for four years, was a repeat chondrosarcoma. Adjuvant therapy has no role in treatment of these tumours, for which the only curative measure is radical surgery. We performed anteroposterior resection and spinal reconstruction on all three patients. CT scan shows that all three have been tumour-free for the past 30 months. All three are neurologically intact. Because of pulmonary complications, two have required extended hospitalisation. In the literature, a five-year survival rate is reported in 50% of cases. Good surgical planning and execution are vital in dealing with chondrosarcoma of the spine

We reviewed 124 patients with a conventional pelvic chondrosarcoma who had been treated over a period of 20 years. We recorded the type of tumour (central or peripheral), type of operation (limb salvage surgery or hemipelvectomy), the grade of tumour, local recurrence and/or metastases, in order to identify the factors which might influence survival. More satisfactory surgical margins were achieved for central tumours or in those patients treated by hemipelvectomy. However, grade 1 tumours, whatever the course, did not develope metastases or cause death, while grade 3 tumours had the worst outcome and prognosis. Central, high-grade tumours require aggressive surgical treatment in order to achieve adequate surgical margins, particularly in those lesions located close to the sacroiliac joint. By contrast, grade 1 peripheral chondrosarcomas may be treated with contaminated margins in order to reduce operative morbidity, but without reducing survival

Twenty-three patients with scapular chondrosarcomas presented to our institution between 1989 and 2003. Twenty-two were treated surgically while one presented with metastases and was treated palliatively. Fourteen patients underwent partial scapulectomy and eight had a Tikhoff-Linberg procedure. There were no local recurrences and only two patients have suffered a systemic recurrence at mean follow-up of fifty-two months. Mean functional scores were: TESS – 88, MSTS 1987 – 27 and MSTS 1993 – 84. Overall, the oncologic and functional outcome for these patients was excellent. To examine the oncologic and functional outcome of patients treated for chondrosarcoma of the scapula. Rates of local recurrence and metastasis for adequately treated chondrosarcomas of the scapula were very low and patient function was quite good. Unlike previous reports in the literature, we found that scapular chondrosarcomas are highly amenable to limb salvage surgery and the oncologic and functional outcomes are excellent. Retrospective review of our prospectively collected database for all patients treated surgically at our institution for scapular chondrosarcoma between 1989 and 2003. Twenty-three patients presented with scapular chondrosarcoma, but one had spine metastases and was treated palliatively. Thus twenty-two patients were treated with limb salvage surgery. There were fourteen males and eight females. One patient presented as a local recurrence. Four tumors were grade one, sixteen grade two and two grade three. Eight were secondary to a primary benign primary tumor of bone. There were fourteen partial scapulectomies and eight Tikhoff-Linberg procedures. Surgical margins were positive in three cases. two patients received post-operative radiation and no patients received adjuvant chemotherapy. At last follow-up, twenty patients were alive with no evidence of disease (90.9%), one was alive with disease and one was dead of disease. There were two systemic recurrences and no local recurrences at an average follow-up of fifty-two months (range 12–113). Mean functional scores were: TESS – 88, MSTS – 1987 27 and MSTS 1993 – 84

Aims. Controversy exists as to what should be considered a safe resection margin to minimize local recurrence in high-grade pelvic chondrosarcomas (CS). The aim of this study is to quantify what is a safe margin of resection for high-grade CS of the pelvis. Methods. We retrospectively identified 105 non-metastatic patients with high-grade pelvic CS of bone who underwent surgery (limb salvage/amputations) between 2000 and 2018. There were 82 (78%) male and 23 (22%) female patients with a mean age of 55 years (26 to 84). The majority of the patients underwent limb salvage surgery (n = 82; 78%) compared to 23 (22%) who had amputation. In total, 66 (64%) patients were grade 2 CS compared to 38 (36%) grade 3 CS. All patients were assessed for stage, pelvic anatomical classification, type of resection and reconstruction, margin status, local recurrence, distant recurrence, and overall survival. Surgical margins were stratified into millimetres: < 1 mm; > 1 mm but < 2 mm; and > 2 mm. Results. The disease-­specific survival (DSS) at five years was 69% (95% confidence interval (CI) 56% to 81%) and 51% (95% CI 31% to 70%) for grade 2 and 3 CS, respectively (p = 0.092). The local recurrence-free survival (LRFS) at five years was 59% (95% CI 45% to 72%) for grade 2 CS and 42% (95% CI 21% to 63%) for grade 3 CS (p = 0.318). A margin of more than 2 mm was a significant predictor of increased LRFS (p = 0.001). There was a tendency, but without statistical significance, for a > 2 mm margin to be a predictor of improved DSS. Local recurrence (LR) was a highly significant predictor of DSS, analyzed in a competing risk model (p = 0.001). Conclusion. Obtaining wide margins in the pelvis remains challenging for high-grade pelvic CS. On the basis of our study, we conclude that it is necessary to achieve at least a 2 mm margin for optimal oncological outcomes in patients with high-grade CS of the pelvis. Cite this article: Bone Joint J 2021;103-B(6):1150–1154

Chondrosarcoma are rare malignant tumors. About the biological characteristics of chondrosarcoma is little-known [. 2. ]. Endothelin and its receptors are involved in regulating angiogenesis and metastatic dissemination [. 1. ]. The aim of this study is first to identify if chondrosarcoma are expressing endothelin-1 (ET-1) and the endothelin-receptors and thereupon to identify potential molecular markers for new target therapies. Another aim is to determine if endothelin is a prognostic factor in chondrosarcoma. 32 cases were investigated clinically and histopathologically. The expression of vascular endothelial growth factor (VEGF), Endothelin-1, Endothelin-Receptor-A (ETR-A) and Endothelin-Receptor-B (ETR-B) were determined. All data were analyzed by Fisher’s exact test (p< 0,05). All tumors show an expression of either ET-1, ETR-A or ETR-B. Chondrosarcomas with grade (G) I are mostly expressing less than 10-% ET-1 in cells, Chondrosarcomas G II are expressing in most cases between 10–50% and nearly all Chondrosarcoms G III more than 50%. In addition ET-1-expression is correlating with the histological grading. The patients also show a significant high metastatic dissemination probability at the time when tumor samples present more than 10%-storing ET-1-cells. The intensity of ET-1-expression is correlating with VEGF, which is the most important angiogenetic factor in tumors. Chondrosarcomas are expressing ET-1, ETR-A and ETR-B. ET-1 seems to play a role in the angiogenesis of chondrosarcoma. Increased expression of ET-1 is accompanied with a high probability of metastatic dissemination. Endothelin receptor antagonists, which are used for example in prostate and breast cancer, can represent a potential therapy for chondrosarcoma [. 1. ]. Experiments on animals and clinical studies are required

Chondrosarcomas are malignant hyaline cartilage tumours of bone. They are clinically resistant to conventional chemo- and radiotherapy and the underlying mechanism is poorly studied. Chemoresistance is a multifactorial process and the inaccessibility due to abundant hyaline cartilaginous matrix surrounding the cells, presence of multi-drug resistance pumps, and expression of anti-apoptotic proteins such as BCL2, have been suggested. Our aim was to study chemoresistance mechanisms in chondrosarcoma. We first studied the sensitivity of chondrosarcoma cell lines (SW1353, CH2879, JJ012, OUMS27) and 2 primary cultures for doxorubicin and cisplatin. We used a 3D pellet model of CH2879 to study doxorubicin incorporation. To investigate whether chondrosarcoma cells could be resensitised to chemotherapy we tested the BH3 mimetic ABT737 inhibiting anti-apoptotic BCL2 family proteins. Cell viability was assessed using a WST assay for mitochondrial activity. Dose response curves showed that chondrosarcoma cell lines and cultures are partially resistant to doxorubicin, while primary cultures were completely resistant to cisplatin. In 3D cell pellets, with morphology strongly resembling high grade chondrosarcoma, doxorubicin incorporation was confirmed. Chondrosarcoma cells responded to ABT737 with a >60% reduction in cell viability at high concentrations (25μM). Combination treatment allowing 2 days between ABT737 and chemotherapy addition led to a complete reduction of cell viability in all cell cultures. In conclusion, chondrosarcoma cell lines show a partial response to doxorubicin and less response to cisplatin. The incorporation of doxorubicin in the cells in a 3D pellet model indicates that resistance is not caused by inaccessibility of the cells for the drugs nor by multi-drug resistance pump activity. By combining BCL2 inhibition with Doxorubicin treatment, a complete reduction of cell viability was obtained. This suggests that BCL2 overexpression plays an important role in chemoresistance of chondrosarcoma, and turning on the apoptotic machinery by BCL 2 inhibition can render them chemosensitive