Aims. Ilium is the most common site of pelvic Ewing’s sarcoma (ES). Resection of the ilium and iliosacral joint causes pelvic disruption. However, the outcomes of resection and reconstruction are not well described. In this study, we report patients’ outcomes after resection of the ilium and iliosacral ES and reconstruction with a tibial strut allograft. Methods. Medical files of 43 patients with ilium and iliosacral ES who underwent surgical resection and reconstruction with a tibial strut allograft between January 2010 and October 2021 were reviewed. The lesions were classified into four resection zones: I. 1. , I. 2. , I. 3. , and I. 4. , based on the extent of resection. Functional outcomes, oncological outcomes, and surgical complications for each resection zone were of interest. Functional outcomes were assessed using a Musculoskeletal Tumor Society (MSTS) score and Toronto Extremity Salvage Score (TESS). Results. The mean age of the patients was 17 years (SD 9.1). At a mean follow-up of 70.8 months (SD 50), the mean functional outcomes were 24.2 points (SD 6.3) for MSTS and 81 points (SD 11) for TESS. The mean MSTS and TESS scores were associated with the iliac resection zone (< 0.001). Nine patients (20.9%) had local recurrence. The recurrence was not associated with the zone of iliac resection (p = 0.324). The two-year disease-free survival of the patients was 69.4%. The mean time to graft union was longer in patients with the I. 4. resection zone (p < 0.001). The complication rate was 34.9%, and nerve palsy (11.6%) was the most common. The rate of surgical complications was not associated with the resection zone. Conclusion. Reconstruction using tibial strut allograft is an efficient procedure after the resection of the ilium and iliosacral ES. Functional outcomes and complications of iliac ES depend on the resection zone, and inferior outcomes could be generally expected when more segments of the pelvic ring are resected, even if it is reconstructed. Cite this article: Bone Jt Open 2024;5(5):385–393

Ewing’s sarcoma principally arises in bone but can also present as a soft tissue tumour. Very few studies have assessed the outcomes of extra-skeletal Ewing’s sarcomas. This study compares the oncological outcomes of the two forms of Ewing’s sarcomas to see if there is any difference in prognostic factors. 198 patients with primary, non metastatic Ewing’s sarcoma diagnosed between 1980 and 2005 were identified from our database. There were 118 males and 80 females with a median age of 15 years. The three most common sites of diagnosis were the femur (24%), pelvis (15%) and tibia (13%). There were 169(85%) bony Ewing’s and 29 (15%) extra-skeletal Ewing’s sarcomas. All patients received chemotherapy. 86% of the patients had surgery for local control but 28(14%) patients had radiotherapy. The overall survival at five years was 89% and was related to the age of patient (92% < 16years p=0.005), size (p=0.03) and site of tumour (p=0.004) as well as the response to chemotherapy. There was no difference in the overall survival of patients with bony Ewing’s (90%) and extra-skeletal Ewing’s (85%) (p=0.85). There was a 10% risk of local recurrence at 5 years with site of tumour (p=0.01) and surgical excision (p=0.05) being significant prognostic factors. The risk of local recurrence was also not related to the type of Ewing’s sarcoma. This large series has shown that the oncological outcomes of Ewing’s sarcoma is related to tumour characteristics, patient age and treatment factors and not determined by the tissue component

The aim of this study was to identify whether there was any difference in patient, tumour, treatment or outcome characteristics between patients with skeletal or extra-skeletal Ewing’s sarcoma. We identified 300 patients with new primary Ewing’s sarcoma diagnosed between 1980 and 2005 from the centres’ local database. There were 253 (84%) with skeletal and 47 (16%) with extra-skeletal Ewing’s sarcomas. Although patients with skeletal Ewing’s were younger (mean age 16.8 years) than those with extra-skeletal Ewing’s sarcoma (mean age 27.5 years), there was little difference between the groups in terms of tumour stage or treatment. Nearly all the patients were treated with chemotherapy and most had surgery. There was no difference in the overall survival of patients with skeletal (64%) and extra-skeletal Ewing’s sarcoma (61%) (p = 0.85), and this was also the case when both groups were split by whether they had metastases or not. This large series has shown that the oncological outcomes of Ewing’s sarcoma are related to tumour characteristics and patient age, and not determined by whether they arise in bone or soft tissue

Aims. The purpose of this study was to review a large cohort of patients and further assess the correlation between the histological response to chemotherapy in patients with Ewing’s sarcoma with the overall (OS) and event-free survival (EFS). Patients and Methods. All patients treated for Ewing’s sarcoma between 1980 and 2012 were reviewed. Of these, 293 patients without metastases at the time of diagnosis and treated with chemotherapy and surgery were included. Patients were grouped according to the percentage of necrosis after chemotherapy: Group I: 0% to 50%, Group II: 51% to 99% and Group III: 100%. Results. The mean age at diagnosis was 16 years (1 to 62) and the mean follow-up was 9.1 years (six months to 32.6 years). The OS and EFS for the series were 75% and 65% at five years. There were significant differences in survival between the groups of necrosis: 0% to 50% (OS: 49% and EFS: 45% at five years, respectively) compared with 51% to 99% (OS: 72% and EFS: 59% at five years, respectively) and 100% (OS: 94% and EFS: 81% at five years, respectively) (p <  0.001). There were no significant differences in survival between patients treated between 1980 and 1989 compared with those treated between 1990 and 1999, and those treated between 2000 and 2012 (p = 0.55). Conclusion. Only patients with 100% necrosis after chemotherapy should be classified as having a good response to chemotherapy because they have significantly better rates of survival compared with those with any viable tumour in the surgical specimen. Cite this article: Bone Joint J 2016;98-B:1138–44

Aim: To review the epidemiology, prognostic factors and outcome of treatment for extra-osseous Ewing’s sarcoma. Method: Thirty-four patients with a diagnosis of extra-osseous Ewing’s sarcoma were identified from a prospectively gathered national tumour database between 1961 and 2005. Patient demographics, clinical features, tumour stage, location and size, treatment received, local recurrence, metastasis and survival were all recorded. Survival was analysed using Kaplan-Meier methods. The average follow up was 45 months. Results: The annual incidence of extra-osseous Ewing’s was 0.2 per million of population between 1970 and 2004. The five-year survival rate for extra-osseous Ewing’s was 62%, which is significantly better than previously reported in the literature. Indicators of a poor prognosis were extra-compartment spread of tumour, local recurrence and metastasis. The recorded annual incidence of extra-osseous Ewing’s sarcoma increased during the period of this study. Conclusions: Extra-osseous Ewing’s sarcoma appears to have similar demographics and the outcome following modern treatment is better than previously reported and no worse than that reported for osseous Ewing’s

Aims. The aim of this study was to analyse a group of patients with non-metastatic Ewing’s sarcoma at presentation and identify prognostic factors affecting the development of local recurrence, in order to assess the role of radiotherapy. Patients and Methods. A retrospective review of all patients with a Ewing’s sarcoma treated between 1980 and 2012 was carried out. Only those treated with chemotherapy followed by surgery and/or radiotherapy were included. Patients were grouped according to site (central or limb) for further analysis of the prognostic factors. Results. A total of 388 patients were included in the study. Of these, 60 (15%) developed local recurrence at a mean median of 27 months (. sd. 24, range 7 to 150) and the five-year local recurrence-free survival (5yrLRFS) was 83%. For central tumours, the size of the tumour and histological response to chemotherapy were found to be significant factors for local recurrence. For limb tumours, local recurrence was affected by intralesional and marginal resections, but not by the histological response to chemotherapy. Radiotherapy in those with a marginal resection reduced the risk of local recurrence (5yrLRFS: 96% versus 81%, p = 0.044). Conclusion. Local recurrence significantly affects the overall survival in patients with a Ewing’s sarcoma. For those with a tumour in a limb, radiotherapy reduced the risk of local recurrence, especially in those with a marginal margin of excision, but the effect in central tumours was less clear. Radiotherapy for those who have had a wide margin of resection does not reduce the risk of local recurrence, regardless of the histological response to chemotherapy. Cite this article: Bone Joint J 2018;100-B: 247–55

We review the treatment of pelvic Ewing’s sarcoma by the implantation of extracorporeally-irradiated (ECI) autografts and compare the outcome with that of other reported methods. We treated 13 patients with ECI autografts between 1994 and 2004. There were seven males and six females with a median age of 15.7 years (interquartile range (IQR) 12.2 to 21.7). At a median follow-up of five years (IQR 1.8 to 7.4), the disease-free survival was 69% overall, and 75% if one patient with local recurrence after initial treatment elsewhere was excluded. Four patients died from distant metastases at a mean of 17 months (13 to 23). There were three complications which required operative intervention; one was a deep infection which required removal of the graft. The functional results gave a mean Musculoskeletal Tumor Society score of 85% (60% to 97%), a mean Toronto extremity salvage score of 86% (69% to 100%) and a mean Harris hip score of 92 (67 to 100). We conclude that ECI grafting is a suitable form of treatment for localised and resectable pelvic Ewing’s sarcoma

Cellular mechanisms that account for tumour osteolysis associated with Ewing’s sarcoma are uncertain. Osteoclasts are marrow-derived multinucleated cells that effect tumour osteolysis. Osteoclasts are known to form from macrophages by both receptor activator for nuclear factor κB ligand (RANKL)-dependent and RANKL-independent mechanisms. In this study our aim has been to determine whether tumour-associated macrophages (TAMs) isolated from Ewing’s sarcoma are capable of differentiating into osteoclasts and to characterise the cellular and humoral mechanisms whereby this occurs. TAMs were isolated from two Ewing’s sarcomas and cultured on both coverslips and dentine slices for up to 21 days with soluble RANKL and human macrophage colony stimulating factor (M-CSF). Osteoclast formation from TAMs (CD14+) was evidenced by the formation of tartrate–resistant acid phosphatase and vitronectin receptor-positive multinucleated cells which were capable of carrying out lacunar resorption. This osteoclast formation and resorption was inhibited by the addition of the bisphosphonate, zoledronate. Osteoclast formation was also seen when Ewing’s sarcoma-derived TAMs were cultured with TNF α in the presence of M-CSF. We also found that TC71 Ewing’s sarcoma cells were capable of independently stimulating osteoclast formation through the release of a soluble factor. These results indicate that TAMs in Ewing’s sarcoma are capable of osteoclast differentiation by both RANKL-dependent and RANKL-independent mechanisms and that Ewing’s sarcoma cells produce an osteoclastogenic factor. The role bisphosphonates may play in inhibiting osteoclast formation and osteolysis in Ewing’s sarcoma merits further investigation

Introduction: A retrospective analysis was performed to determine the oncological outcome of patients with Ewing’s sarcoma of the spine treated with combined chemotherapy and radiotherapy for definitive local control. Materials and Methods: Fifteen patients were identified from the Scottish Bone Tumour Registry with a histologically confirmed Ewing’s sarcoma affecting the axial skeleton. All case notes and imaging were retrospectively reviewed. Results: Primary vertebral Ewing’s sarcoma accounted for 8.3% of all malignant spinal lesions in our registry. The mean age was 17.8 years (between 4 and 39 years). There was a male predilection with 9 male and 6 female patients. Site was evenly distributed between cervical (4), dorsal (5) and lumbosacral (6) regions. Progressively worsening back pain was the first symptom in all the patients. Satisfactory imaging studies were available in all with plain radiographs (15), bone scan (11), CT-scan (12) and MR Scan (9) patients. Biopsy was performed in 11 patients and surgical treatment was carried out in 3 patients including curettage (2) and excision with bone grafting (1). All patients were treated with adjuvant radiotherapy while 87% also received adjuvant chemotherapy. Seven patients were alive with no evidence of disease at a mean 6 year follow-up. Six patients died of metastatic disease, one due to local recurrence and one with persistent primary disease. The mean follow-up time was 65 months (median 28 months; ranging from 12 to 218 months). Conclusions: Primary vertebral Ewing’s sarcoma comprised 8.3% of our National Registry’s primary malignant spinal lesions. Progressive vertebral pain in the late second decade and male gender should raise the suspicion of Ewing’s sarcoma. Ewing’s sarcoma of the spine treated with combined chemotherapy and radiotherapy for definitive local control achieved a 45% five year survival

Aims. Present the outcomes of those patients diagnosed with Ewing's Sarcoma of the foot within the past 10 years and treated at the Royal National Orthopaedic Hospital's Bone Tumour Unit, Stanmore. Methods. Retrospective study of the cases identified from the pathology database. Notes reviewed for presentation, treatment and follow up. TESS (Toronto Extremity Salvage Score) and MSTS (Musculoskeletal tumour score) were calculated. Results. 6 patients identified with positive diagnosis of Ewing's Sarcoma of the Foot. Male:Female ratio of 5:1. Age range 15–31 (Mode 25). 4 cases skeletal, 2 extra skeletal. All cases reviewed by supra-regional MDT and received adjuvant and neo-adjuvant chemotherapy. All except one patient underwent limb-salvage surgery. The MDT decision for the remaining patient was that amputation was the only viable surgical option but the patient and his parents requested radiotherapy without surgical treatment. Mean survival 40 months (15–107 months). All patients survive at time of submission. Mean MSTS/TESS scores 93% (80–100%) and 94.6% (85–100) respectively. Discussion. All patients reported a delay between first presentation and referral to the sarcoma unit. This experience is common across the literature for this rare pathology. Lowest scores were submitted by the two patients who had amputation of their great toe. All patients are happy with their outcome and decision to salvage their limb. All patients scored themselves as “not at all disabled” and two stated this would not have been their response if they had lost their foot. Conclusion. Amputation is psychologically difficult to accept and patients are more receptive to limb salvage surgery. Our patients demonstrate good functional outcome. Our experience at Stanmore suggests that limb salvage surgery with adequate MDT surveillance for Ewing's Sarcoma of the Foot can be a viable alternative to amputation

Despite local treatment with systemic chemotherapy in Ewing’s sarcoma family tumours (ESFT), patients with detectable metastases at presentation have a markedly worse prognosis than those with apparently localised disease. We investigated the clinical, pathological and laboratory differences in 888 patients with ESFT, 702 with localised disease and 186 with overt metastases at presentation, seen at our institution between 1983 and 2006. Multivariate analyses showed that location in the pelvis, a high level of serum lactic dehydrogenase, the presence of fever and a short interval between the onset of symptoms and diagnosis were indicative of metastatic disease. The rate of overt metastases at presentation was 10% without these four risk factors, 22.7% with one, 31.4% with two, and 50% for those with three or four factors. We concluded that in ESFT the site, the serum level of lactic dehydrogenase, fever, and the interval between the onset of symptoms and diagnosis are indicators of tumours having a particularly aggressive metastatic behaviour

We reviewed the treatment and clinical outcome of 32 consecutive patients with Ewing’s sarcoma who presented with or developed pathological fracture after biopsy between 1984 and 2004. The minimum follow-up was 18 months. The mean age at diagnosis was 20 years (5 – 51). There were 18 males and 14 females. All patients were newly diagnosed and had localized disease at the time of diagnosis. 21 patients presented with pathological fracture while 11 patients developed fracture during the course of chemotherapy. The femur was the most common location in 15 patients. All the patients had chemotherapy according to the protocol current at the time of treatment. 6 patients had radiotherapy alone while 26 patients underwent surgical excision and reconstruction. Of the patients who had surgery, 7 patients had adjuvant radiotherapy. Fracture healing was the norm after pre-operative chemotherapy. Surgical margins were wide in 17 patients, marginal in 4 and intralesional in 3 patients. Local recurrence developed in one patient (3%). Metastases occurred in 12 patients (37%). At the time of review 16 patients were free of disease, 3 were alive with disease and 13 patients had died of disease. The cumulative 5 year metastases free and overall survival in all the patients was 58% and 61 % respectively and similar to patients with Ewing’s sarcoma without fracture treated at our centre. The prognosis of patients who presented with fracture was exactly similar to those who developed fracture in the course of treatment. We conclude that limb preserving surgery is perfectly safe in patients with Ewing’s sarcoma who have associated pathological fracture and survival is not in any way compromised. Survival of patients who present with fracture is similar to those who develop fracture in the course of treatment. The exact role of adjuvant radiotherapy in these patients needs to be clarified

We reviewed the treatment and clinical outcome of 32 consecutive patients with Ewing’s sarcoma who presented with or developed pathological fracture after biopsy between 1984 and 2004. The minimum follow-up was 18 months. The mean age at diagnosis was 20 years (5 – 51). There were 18 males and 14 females. All patients were newly diagnosed and had localized disease at the time of diagnosis. 21 patients presented with pathological fracture while 11 patients developed fracture during the course of chemotherapy. The femur was the most common location in 15 patients. All the patients had chemotherapy according to the protocol current at the time of treatment. 7 patients had radiotherapy alone while 25 patients underwent surgical excision and reconstruction. Of the patients who had surgery, 7 patients had adjuvant radiotherapy. Fracture healing was the norm after pre-operative chemotherapy. Surgical margins were wide in 17 patients, marginal in 4 and intralesional in 3 patients. Local recurrence developed in one patient (3%). Metastases occurred in 12 patients (37%). At the time of review 16 patients were free of disease, 3 were alive with disease and 13 patients had died of disease. The cumulative 5 year metastases free and overall survival in all the patients was 58% and 61 % respectively and similar to patients with Ewing’s sarcoma without fracture treated at our centre. The prognosis of patients who presented with fracture was exactly similar to those who developed fracture in the course of treatment. We conclude that limb preserving surgery is perfectly safe in patients with Ewing’s sarcoma who have associated pathological fracture and survival is not in any way compromised. Survival of patients who present with fracture is similar to those who develop fracture in the course of treatment. The exact role of adjuvant radiotherapy in these patients needs to be clarified

Introduction: The role of surgery for local control in the multimodal management of Ewing’s sarcoma has substantially increased during the past 20 years. However, selection bias due to location (extremities vs axial skeleton) and relatively non-homogeneous treatment received by patients in multi-institutional trials may limit objective evaluation and comparison of the relative role of surgery and radiation therapy in this setting. Purpose of this study was to review a large series of patients homogeneously treated at a single institution. Methods: 268 patients with non-metastatic Ewing’s sarcoma of the extremities treated by contemporary multimodal management were reviewed. Chemotherapy was administered according to 4 sequential protocols of adjuvant (1) and neoadjuvant (3) treatment. Local control consisted of surgery in 136 patients, surgery and radiation therapy in 70 patients, and radiation therapy in 60 patients. Two patients underwent only chemotherapy. Results: The 5-year event-free survival (EFS) and overall survival (OS) were 62 and 69 per cent respectively. The rates of 5-year EFS and local control were significantly lower in patients treated with radiation therapy compared to patients treated by surgery or surgery and radiation therapy (48 vs 66 per cent, p=0.002; 80 vs 94 per cent, p= 0,0001). In group 3 (Radiation Therapy only) there were also 6 secondary malignancies. Conclusion: Surgery was associated with better survival and local control in this series. In our opinion, surgery should always be considered in the local treatment of Ewing’s sarcoma of the extremities. Postoperative Radiation Therapy must be added in cases of inadequate surgical margins

The role of radiotherapy and/or surgery in the local treatment of Ewing’s sarcoma has still to be determined. The outcome of Ewing’s sarcoma may differ according to its location and a selection bias towards surgery limits the ability to compare methods of local treatment. We have carried out a retrospective review of 91 consecutive patients treated for non-metastatic Ewing’s sarcoma of the femur. They received chemotherapy according to four different protocols. The primary lesion was treated by surgery alone (54 patients), surgery and radiotherapy (13) and radiotherapy alone (23). One was treated by chemotherapy alone. At a median follow-up of ten years, 48 patients (53%) remain free from disease, 39 (43%) have relapsed, two (2%) have died from chemotherapeutic toxicity and two (2%) have developed a radio-induced second tumour. The probability of survival without local recurrence was significantly (p = 0.01) higher in patients who were treated by surgery with or without radiotherapy (88%) than for patients who received radiotherapy alone (59%). The five- and ten-year overall survival rates were 64% and 57%, respectively. Patients who were treated by surgery, with or without radiotherapy, had a five- and ten-year overall survival of 64%. Patients who received only radiotherapy had a five- and ten-year survival of 57% and 44%, respectively. Our results indicate that in patients with Ewing’s sarcoma of the femur, better local control is achieved by surgical treatment (with or without radiotherapy) compared with the use of radiotherapy alone. Further studies are needed to verify the impact of this strategy on overall survival

The outcome for patients with Ewing's sarcoma recurrence is poor. Local recurrences occur in 8%-25%of these patients. The aim of the study was to analyze the patients who had a local recurrence to identify factors predicting the local recurrence and if it could be prevented. Methods. A retrospective analysis of 650 patients who had a diagnosis of Ewing's sarcoma treated between 1975 and 2009 at a single institution was performed and 64 patients (10%) who had a local recurrence were identified and analysed. Results. Fifteen patients had metastases at diagnosis.20 patients had chemotherapy and radiotherapy only while 44 had chemotherapy and surgery +/− post op radiotherapy. Thirteen patients who were suitable for post –operative radiotherapy could not receive the treatment due to various reasons like biological reconstruction. The estimated 5 years survival for the patients was 15%. The risk of local recurrence is higher if the tumour is located in the axial skeleton, treatment with chemotherapy and radiotherapy alone [location and size of the tumour precluding surgery]. The risk of local recurrence is higher if the tumour was in the fibula or radius. One out of three patients who have good response to chemotherapy still went on to develop a LR. The use of biological reconstruction and younger age group often resulted in deferral of post-operative radiotherapy. Location and type of treatment can predict LR. Surgery with clear margins and post-operative radiotherapy given when indicated may reduce the incidence of LR

Introduction and Aims: To assess and compare treatment of pelvic Ewing’s sarcoma, particularly extracorporeal irradiation (ECI) and re-implantation of bone segments. Method: We reviewed all patients presenting to the New South Wales Bone Tumor Service with Ewing’s sarcoma of the pelvis from 1995 until 2003. All received chemotherapy. There were 17 patients. Resection was performed in 14 cases: 12 were reconstructed by ECI and re-implantation of the bone segment; one with autograft and THR; one with allograft and THR. Three patients with sacral lesions had chemotherapy and radiotherapy only. All margins were clear. All patients were clinically and radiologically reviewed. Three scoring systems were used: The Musculoskeletal Tumor Society score (MSTS), the Toronto Extremity Salvage Score (TESS), and the Harris Hip Score (HHS). Results: The average age at presentation was 18 years (range six to 35). There were seven males and 10 females. One patient presented with metastatic disease. Survivor follow-up ranged from 25 to 105 months (mean 55). In those who developed metastases these were detected at a mean of 27 months (range one to 79). Deaths occurred at a mean 31 months (range eight to 65). Fourteen underwent surgery. Seven had THR as part of their reconstruction. There have been no local recurrences after surgery. Six patients have died, 11 patients are alive (65%), one with metastatic disease. Overall disease-free survival is 59%. The disease-free survival in those who underwent ECI and re-implantation is 75% (minimum two-year follow-up). Functional outcome is good. The TESS mean was 83 (range 60–100). The MSTS score mean 85 (range 60–97). The HHS mean 92 (range 67–100). Radiologically solid bony union at the osteotomy sites was the norm. Lysis existed at two periacetabular osteotomies, around the posterior iliac crest of one osteotomy, and a fibrous union occurred at one sacro-iliac joint with breakage of the sacro-iliac screws. There have been no graft fractures. Conclusion: The best surgical management for these difficult cases is extracorporeal irradiation and re-implantation of bone segments

Between 1948 and 2004, we report 34 patients with Ewing’s sarcoma of pelvis accrued from Scottish Bone Tumour Registry, aiming to identify the prognostic factors and the influence of various treatment modalities on outcome. There were 19 male and 15 female patients at a mean age of 19 years (range, 3 to 48 years). The Pain was main presenting symptom in 30, swelling in 12 and restriction of hip movements in 11 patients. The commonest anatomical site was ilium. Local control was achieved by surgery, radiotherapy (n=25), chemotherapy (n=23) or a combination. The survival correlated significantly with chemotherapy protocols in favour of the group that received ifosamide (p< 0.01). Metastases at presentation was the most important factor determining survival (P< 0.01). Among the patients who presented without metastases (n=25), there was no statistically significant difference in survival based on the anatomical location of the tumour, age or sex. The mean time to lung metastases from the date of presentation was 13 months, while bone metastases presented at an average of 20 months. None of the patients with the metastasis or local recurrence survived. There were 5 local and 17 systemic (metastatic) relapses. The mean duration of survival was 13 months. With advances in imaging, aggressive chemotherapy, surgery and conformal radiotherapy which can deliver high dose of radiation with precision, it is possible to achieve a cure rate of more that 50% in non-metastatic pelvic Ewing’s sarcoma. The results of this study favour a middle-path regime combining all treatment modalities

We studied the CT and MR scans, and the histology of 50 patients with primary Ewing’s sarcoma of bone to determine the association between the change in tumour volume and necrosis after chemotherapy, and to ascertain their influence on prognosis. The mean age of the patients was 17 years. The limbs were involved in 40 and the axial bones in ten. The volume of the tumour at diagnosis varied from 31 to 1790 ml. There was a significant relationship between necrosis and the measured change in volume of the tumour after chemotherapy. Progression of the tumour despite chemotherapy was seen only in patients with necrosis of grades 4 to 6. Necrosis significantly influenced survival (p < 0.05), but the effect of change in volume was less significant. Change in volume of the tumour is a good predictor of necrosis induced by chemotherapy. Necrosis is a strong prognostic factor in Ewing’s sarcoma

Aim. To determine the overall survival of patients with Pelvic Ewing's Sarcoma treated in our unit and to identify prognostic factors in pelvic primaries that could be used to select patients who would most likely benefit from high intensity treatment. Method. Between 1977 and 2009, 80 male and 66 female patients aged 2 to 60 (mean, 18) years with Pelvic Ewing's Sarcomas were retrospectively reviewed from the Royal Orthopaedic Hospital Oncology Service Registry. Treatments included surgery, radiotherapy, chemotherapy, or any of them in combination. Event-free (from presentation to recurrence) and overall (from presentation to death/latest follow-up) survival rates were calculated using the Kaplan- Meier method. Influence of various factors (age at diagnosis, gender, tumour site, metastasis at presentation, surgery (and surgical margins), radiotherapy, and type of treatment on survival was assessed using SPSS 14.0 statistical software. Results. Out of the 146 patients, 128 had available follow up and were eventually included in the analysis. Ninety two patients died (63%) within a mean follow-up of 51 months (range, 3-343). In multivariate analysis, metastases at diagnosis and development of metastases were associated with decreased survival. In terms of the type of treatment received, chemotherapy and surgery was found to be associated with increased survival rates compared to chemotherapy and radiotherapy (p=0.04). Factors that were statistically significant associated with the development of metastasis were location at the periacetabular region and development of local recurrence. In multivariate analysis, only the development of local recurrence was significantly associated with increased risk for metastasis development (p=0.003). No factor was found to associate significantly with the development of local recurrence. Conclusion. Currently, the optimal management of Pelvic Ewing's Sarcoma is controversial but our study shows increased survival rates with chemotherapy and surgery treatment