Prognostic Factors and Patterns of Relapse in Ewing Sarcoma Patients Treated With Chemotherapy and R0 Resection

[Radiotherapy in Ewing sarcomas]

Ewing sarcomas are the 2nd cause of malignant bone tumors in children and young adults. After induction chemotherapy, local treatment is essential and most often includes surgery of the primary tumor. Radiotherapy may be necessary as an exclusive local procedure when surgery is not possible, or in an adjuvant situation when the surgical procedure must be completed (incomplete resection or poor histological response in particular). Radiotherapy can also concern metastatic sites, particularly in cases of pulmonary metastases and/or in an oligo-metastatic situation. This article provides a review of current indications for radiotherapy, technical modalities of irradiation (delineation of volumes, recommended doses), and the results of recent studies.

A reduction in tumor volume exceeding 65% predicts a good histological response to neoadjuvant chemotherapy in patients with Ewing sarcoma

OBJECTIVE

No consensus exists for tumor volume response criteria in patients with Ewing sarcoma. This study aimed to identify an optimal cutoff for predicting a good histological response by analyzing tumor volume changes and tumor necrosis after neoadjuvant chemotherapy.

MATERIALS AND METHODS

We performed a retrospective analysis of 184 Ewing sarcoma patients, analyzing tumor volume changes before and after neoadjuvant chemotherapy. Patients were divided into two groups based on histological response: good (tumor necrosis ≥ 95%) and poor (tumor necrosis < 95%) responders. The receiver operating characteristic (ROC) area under the curve (AUC) method was used to determine the optimal thresholds for predicting the histological response. Additionally, the prognostic value of this cutoff for relapse-free survival was assessed.

RESULTS

Out of 184 patients, 83 (45%) had tumor necrosis ≥ 95%, while 101 (55%) had tumor necrosis < 95%. ROC analysis identified the optimal cutoff for a good histological response as over 65% tumor volume reduction (AUC = 0.69; p < 0.001). Patients with volume reduction of ≥ 65% had a higher likelihood of a good histological response than those with lesser reductions (p = 0.004; odds ratio = 2.61). Multivariable analysis indicated a correlation between poor histological response and reduced relapse-free survival (hazard ratio = 2.17; p = 0.01), while tumor volume reduction itself did not impact survival.

CONCLUSION

We reported that a tumor volume reduction of ≥ 65% was able to predict a good histological response in Ewing sarcoma patients. We recommend preoperative tumor volume assessment to identify patients at greater risk for poor histological response who could benefit from more intensive chemotherapy protocols or additional radiotherapy.

Survival outcomes in pediatric patients with metastatic Ewing sarcoma who achieve a rapid complete response of pulmonary metastases

PURPOSE

Our objectives were to compare overall survival (OS) and pulmonary relapse between patients with metastatic Ewing sarcoma (EWS) at diagnosis who achieve rapid complete response (RCR) and those with residual pulmonary nodules after induction chemotherapy (non-RCR).

PATIENTS AND METHODS

This retrospective cohort study included children under 20 years with metastatic EWS treated from 2007 to 2020 at 19 institutions in the Pediatric Surgical Oncology Research Collaborative. Chi-square tests were conducted for differences among groups. Kaplan-Meier curves were generated for OS and pulmonary relapse.

RESULTS

Among 148 patients with metastatic EWS at diagnosis, 61 (41.2%) achieved RCR. Five-year OS was 71.2% for patients who achieved RCR, and 50.2% for those without RCR (p = .04), and in multivariable regression among patients with isolated pulmonary metastases, RCR (hazards ratio [HR] 0.42; 95% confidence interval [CI]: 0.17-0.99) and whole lung irradiation (WLI) (HR 0.35; 95% CI: 0.16-0.77) were associated with improved survival. Pulmonary relapse occurred in 57 (37%) patients, including 18 (29%) in the RCR and 36 (41%) in the non-RCR groups (p = .14). Five-year pulmonary relapse rates did not significantly differ based on RCR (33.0%) versus non-RCR (47.0%, p = .13), or WLI (38.8%) versus no WLI (46.0%, p = .32).

DISCUSSION

Patients with EWS who had isolated pulmonary metastases at diagnosis had improved OS if they achieved RCR and received WLI, despite having no significant differences in rates of pulmonary relapse.

Ewing Sarcoma-Chest Wall Reconstruction Following Resection of Rare Primary Chest Wall Tumor

Ewing sarcoma (ES) represents the second most common primary osseous malignancy in children and young adults, most often occurring in the diaphysis of the long bones. While rare, ES can present as an osseous tumor of the ribs and/or chest wall. These tumors are known as Askin's tumors and most commonly present with symptoms resembling pneumonia. We report the case of a 26-year-old man who was found to have a right lung mass extending into his anterolateral chest wall after presenting to the hospital for evaluation of unremitting chest pain. Biopsy was performed and the patient diagnosed with ES. After completion of neoadjuvant chemotherapy, the patient underwent resection of the right chest wall mass. The chest wall was reconstructed in a novel fashion with titanium plates and a reinforced tissue matrix patch. Due to a paucity of cases, no treatment or reconstruction algorithm currently exists for management of these malignancies.

Clinical characteristics of primary cutaneous and subcutaneous Ewing sarcoma

OBJECTIVE

Given the rarity of cutaneous/subcutaneous Ewing sarcoma, their clinical characteristics remain poorly understood. In this study, we aimed to analyse the clinical characteristics of patients with cutaneous/subcutaneous Ewing sarcoma and review the treatment strategy.

METHODS

We reviewed the clinical data of 154 patients with Ewing sarcoma who were treated at our hospital between 2005 and 2019. Amongst these patients, 21 patients with cutaneous/subcutaneous Ewing sarcoma were analysed. As a basic strategy, patients with localized disease received intensive chemotherapy (vincristine-doxorubicin-cyclophosphamide/ifosfamide-etoposide), followed by definitive surgery with or without radiotherapy. In total, 15 patients underwent pre-diagnostic resection with macroscopic residue (seven patients) or non-macroscopic residue (eight patients) before intensive chemotherapy.

RESULTS

The median tumour length of the measurable lesions was 3.2 cm, and the ratio of metastasis was significantly lower than the Ewing sarcoma of other anatomical sites (10% vs. 37%, P = 0.013). Despite the pre-diagnostic resection, local recurrence after additional resection and/or adjuvant radiotherapy did not occur in any of the patients with localized disease. Overall survival was significantly higher in patients with cutaneous/subcutaneous Ewing sarcoma than in patients with Ewing sarcoma of other anatomical sites (hazard ratio = 0.33, P = 0.013). The event-free survival rate of cutaneous/subcutaneous Ewing sarcoma was also superior to that of Ewing sarcoma of other anatomical sites (hazard ratio = 0.35, P = 0.01).

CONCLUSIONS

Patients with cutaneous/subcutaneous Ewing sarcoma may have better prognosis than those with Ewing sarcoma at other anatomical sites. Although pre-diagnostic resection without appropriate investigations is not recommended, local control may be recovered by using a combination of additional resection, chemotherapy and radiotherapy.

Datasets for the reporting of primary tumour in bone: recommendations from the International Collaboration on Cancer Reporting (ICCR)

BACKGROUND AND OBJECTIVES

Bone tumours are relatively rare and, as a consequence, treatment in a centre with expertise is required. Current treatment guidelines also recommend review by a specialised pathologist. Here we report on international consensus-based datasets for the pathology reporting of biopsy and resection specimens of bone sarcomas. The datasets were produced under the auspices of the International Collaboration on Cancer Reporting (ICCR), a global alliance of major (inter-)national pathology and cancer organisations.

METHODS AND RESULTS

According to the ICCR's process for dataset development, an international expert panel consisting of pathologists, an oncologic orthopaedic surgeon, a medical oncologist, and a radiologist produced a set of core and noncore data items for biopsy and resection specimens based on a critical review and discussion of current evidence. All professionals involved were bone tumour experts affiliated with tertiary referral centres. Commentary was provided for each data item to explain the rationale for selecting it as a core or noncore element, its clinical relevance, and to highlight potential areas of disagreement or lack of evidence, in which case a consensus position was formulated. Following international public consultation, the documents were finalised and ratified, and the datasets, including a synoptic reporting guide, were published on the ICCR website.

CONCLUSION

These first international datasets for bone sarcomas are intended to promote high-quality, standardised pathology reporting. Their widespread adoption will improve the consistency of reporting, facilitate multidisciplinary communication, and enhance comparability of data, all of which will help to improve management of bone sarcoma patients.

Development and Validation of a Novel Clinical Prediction Model to Predict the Risk of Lung Metastasis from Ewing Sarcoma for Medical Human-Computer Interface

Background. This study aimed at establishing and validating a quantitative and visual prognosis model of Ewing Sarcoma (E.S.) via a nomogram. This model was developed to predict the risk of lung metastasis (L.M.) in patients with E.S. to provide a practical tool and help in clinical diagnosis and treatment. Methods. Data of all patients diagnosed with Ewing sarcoma between 2010 and 2016 were retrospectively retrieved from the Surveillance, Epidemiology, and End Results (SEER) database. A training dataset from the enrolled cohorts was built (n = 929). Predictive factors for L.M. were identified based on the results of multivariable logistic regression analyses. A nomogram model and a web calculator were constructed based on those key predictors. A multicenter dataset from four medical institutions was established for model validation (n = 51). The predictive ability of the nomogram model was evaluated by the receiver operating characteristic (ROC) curve and calibration plot. Decision curve analysis (DCA) was applied to explain the accuracy of the nomogram model in clinical practice. Results. Five independent factors, including survival time, surgery, tumor (T) stage, node (N) stage, and bone metastasis, were identified to develop a nomogram model. Internal and external validation indicated significant predictive discrimination: the area under the ROC curve (AUC) value was 0.769 (95% CI: 0.740 to 0.795) in the training cohort and 0.841 (95% CI: 0.712 to 0.929) in the validation cohort, respectively. Calibration plots and DCA presented excellent performance of the nomogram model with great clinical utility. Conclusions. In this study, a nomogram model was constructed and validated to predict L.M. in patients with E.S. for medical human-computer interface—a web calculator (https://drliwenle.shinyapps.io/LMESapp/). This practical tool could help clinicians make better decisions to provide precision prognosis and treatment for patients with E.S.

Characteristics and Outcomes of Locally Recurrent Retroperitoneal Sarcoma After First Relapse in a Single Tertiary Asian Centre and Applicability of the Sarculator

Objective

Retroperitoneal sarcomas (RPS) comprise of 15% of soft tissue sarcomas where five-year overall survival rate is about 50%. Locoregional recurrences are observed in up to 50% of patients within the first five years following resection. Various factors have been shown to influence survival outcomes, such as histological subtype and tumour size. A nomogram for first relapse locally recurrent RPS was developed using 602 patients from 22 centres. The recurrent RPS Sarculator is available in an electronic interface and includes variables of age, size, margins of re-resection, radiotherapy, chemotherapy and histology to predict for 6-year disease-free survival (DFS) and overall survival (OS). It has not been validated externally. This study aims to validate the Sarculator recurrence nomogram in predicting the survival outcomes of recurrent RPS in an Asian population as well as examine relapse patterns.

Methods

Patients diagnosed with first recurrent RPS from 1 January 2000 to 31 December 2017 with first local relapse and eligible for curative re-resection were retrospectively analysed. The type of surgery was unique for individual patients and suggestions of adjuvant therapy were based on globally recognised standards. Patients were followed up every 3 to 4 months post-operatively for the first 2 to 3 years and 6-monthly to a year thereafter. A R0 or R1 margin is deemed as complete resection, including a microscopically negative margin (R0) and microscopically positive but macroscopically clear margin (R1). R2 is classified as an incomplete resection with tumour rupture or remaining disease. Harrell’s C concordance index was used to determine the nomogram’s discriminative ability and calibration plots were used to assess accuracy. For the calibration, the patients were divided into 3 groups. Death data was retrieved from the National Birth and Death registry for accuracy.

Results

There were 53 patients included in this study. Patient and tumour characteristics have been summarised in Table 1. All patients had their second resection at a single centre. 66.0% had their first resection at the same centre. The median age was 53 (range 21- 79) at diagnosis, median tumour size was 17cm (12cm to 28cm) and median follow-up duration was 44.1 months. The most commonly encountered subtypes were de-differentiated liposarcoma (DDLPS) (56.6%), well-differentiated liposarcoma (WDLPS) (20.8%) and leiomyosarcoma (LMS) (11.3%) with a majority being high-grade (75.5%). The median disease-free interval was 2.9 years (2- 5.3 years) from the first surgery. The median age at second surgery was 56 (21- 79) and all patients had a complete resection (R0/R1). Recurrence patterns differed with subtypes where 90.9% and 9.1% of WDLS, 76.7% and 16.7% of DDLPS and 83.3% and 16.7% of LMS had local and distant relapses respectively from the second surgery. 62.5% of distant relapses was in the lung followed by nodes (18.8%) and liver (12.5%). The 5-year OS from the second surgery was 66.2% (95% CI: 54.3%- 80.8%). The 1-year, 3 years and 6 years DFS were 50.2% (95% CI: 38.2% - 65.9%), 10.4% (4.26% - 25.5%) and 3.91% (0.684% - 22.4%) respectively. Overall, 32 patients (60.4%) had passed away from sarcoma. The concordance indices for 6-year OS and DFS were 0.7 and 0.65 (Figure 1) respectively which represents a fairly accurate prediction by Sarculator.

Conclusion

Our study has shown the Sarculator nomogram for primary recurrent was applicable in our cohort and its potential application in an Asian setting. The Sarculator nomogram will be a useful tool in clinical practice to improve risk stratification and facilitate prognosis-based decision-making. Moving forward, novel therapeutic strategies are required to enhance the prognosis of patients with recurrent RPS.

Ewing sarcoma

Ewing sarcoma is a rare tumor that requires complex multidisciplinary management. This report describes the general management and standard radiotherapy guidelines in both North America (Children's Oncology Group) and Europe (International Society of Pediatric Oncology). Standard treatment involves multiagent induction chemotherapy followed by local treatment with surgery, definitive radiation, or a combination of surgery and radiation followed by additional chemotherapy and consolidation local treatment to metastatic sites. The data supporting the role of chemotherapy, surgery, and radiation and specific radiation therapy guidelines are presented.

Histological response to neoadjuvant chemotherapy in localized Ewing sarcoma of the bone: A retrospective analysis of available scoring tools

AIM

The aim is to evaluate which of the existing scoring systems of histological response to neoadjuvant chemotherapy best stratifies the clinical outcome of patients with localized Ewing sarcoma of bone.

METHODS

474 patients with diagnosis of localized Ewing sarcoma of bone were included. The median follow-up was 13.5 years.

RESULTS

The overall survival and the disease-free survival (DFS) were 70.8% and 63.9% at 5 years. The percentage of histological response to neoadjuvant chemotherapy ranged between 5% and 100% (mean 83%). The agreement between Bologna System and the different percentual cut-offs of histological response to neoadjuvant chemotherapy was high, with kappa statistics of 0.83 for a cut-off of ≥90%; 0.86 for a cut-off of ≥95%; 0.79 for a cut-off of ≥96% and 0.61 for a cut-off of 100%. Statistically higher DFS rates for good responders compared to poor responders were found when using each given system. Model performance indicators showed that Bologna system had a lower AIC score and a higher c-statistics to predict DFS. When the patients classified as good responders using the different percentual cut-offs of histological response to neoadjuvant chemotherapy, were instead re-classified using the Bologna system, statistical differences were noted in DFS within each specific group.

CONCLUSIONS

All scoring tools to evaluate histological response to neoadjuvant chemotherapy offer good predictive value for DFS in localized Ewing's sarcoma of bone. The Bologna system better stratifies those patients with histological response to neoadjuvant chemotherapy between 90 and 99%, representing a more reliable scoring tool in this subset.

Homogenous and Heterogenous Prognostic Factors for Patients with Bone Sarcoma

OBJECTIVE

The aim of this study was to examine the survival rate of patients with different bone sarcomas and to investigate homogenous and heterogenous prognostic factors for different types of bone sarcomas.

METHODS

This is a retrospective analysis of records from the Surveillance, Epidemiology, and End Result (SEER) database. Clear information on the distant metastasis of cancer is provided in the SEER database for patients diagnosed between January 2010 and December 2016. Data for the four types of malignant bone sarcomas were extracted, including osteosarcoma, chondrosarcoma, Ewing sarcoma, and chordoma. Patients with bone sarcomas originated from other sites, diagnosed at autopsy, or indicated in death certification were excluded. The overall survival was calculated for the entire cohort and across different bone sarcomas using the Kaplan-Meier method. A subgroup analysis of the different survival rates of four types of bone sarcomas in various levels of each variable was conducted and the differences were tested with the log-rank test. Cox proportional hazard regression analysis was performed to determine the prognostic factors. Variables with P < 0.05 in the univariate Cox regression analysis were further analyzed using a multivariate Cox regression analysis. The prognostic factors in four groups of bone sarcomas were compared to determine the homogenous and heterogenous factors.

RESULTS

A total of 4732 patients were included with a follow up of 25 (0-83) months. The mean age of patients was 39.7 ± 24.1 years. The 1-year, 3-year, and 5-year overall survival rate for the entire cohort was 86.2% (95% confidence interval [CI]: 85.2%-87.2%), 70.5% (95% CI: 68.9%-72.1%), and 63.0% (95% CI: 61.2%-64.8%), respectively. Factors including age older than 40 years, higher grade, regional and distant stage, tumor in the extremities, T2 stage, bone and lung metastases, and non-surgery were significantly associated with the poor survival of the entire cohort. The mean overall survival duration of patients with chordoma, chondrosarcoma, Ewing sarcoma, and osteosarcoma was 66.86 (95% CI: 64.06-69.66), 63.53 (95% CI: 61.81-65.25), 58.06 (95% CI: 55.49-60.62) and 54.91 (95% CI: 53.14-56.69) months, respectively. Compared with chordoma, the hazard ratio (HR) and 95% CI for patients with chondrosarcoma, Ewing sarcoma, and osteosarcoma were 1.30 (95% CI: 1.04-1.62; P = 0.023), 1.69 (95% CI: 1.33-2.14; P < 0.001), and 2.00 (95% CI: 1.61-2.48; P <0.001), respectively. Different bone sarcomas showed homogenous and heterogenous prognostic factors.

CONCLUSION

Different clinicopathological characteristics and prognoses were revealed in patients with osteosarcoma, chondrosarcoma, Ewing sarcoma, and chordoma. The risk factors can potentially guide prognostic prediction and sarcoma-specific treatment.

Role of Metastatic Site Irradiation in Pediatric Patients With Metastatic Ewing Sarcoma

BACKGROUND

The use of radiation therapy to treat metastases in patients with metastatic Ewing sarcoma (MES) has been controversial and variable. The authors report outcomes and patterns of failure after metastatic site irradiation (MSI).

PROCEDURE

A total of 27 pediatric patients with MES were treated with chemotherapy and received radiation therapy to their primary site. Ten patients additionally received MSI, which consisted of whole-lung irradiation (WLI) in patients with lung metastases. Metastatic sites were followed from diagnosis to the first relapse.

RESULTS

Median follow-up was 29 months. Seventy-eight percent of patients relapsed. Two-year progression-free survival (PFS) and overall survival with and without MSI were 30 versus 29% (log rank P=0.38) and 60 versus 70% (log rank P=0.11), respectively. The median time to relapse among patients who relapsed was 19.5 versus 12.3 months for those receiving MSI versus those who did not (P=0.04).Seven of 20 (35%) patients with lung metastases received WLI±other MSI. Two-year PFS with and without MSI was 43% versus 23% (log rank P=0.02). Among patients with a complete response to computed tomography, 5 of 14 (36%) patients received MSI. Two-year PFS with and without MSI was 60% versus 33% (log rank P=0.04).In the cohort of patients who relapsed, among all metastatic sites at diagnosis, the disease recurred at 15% of irradiated sites and 31% of unirradiated sites. On logistic regression, no factors were statistically associated with increased risk of recurrence at initial sites of metastases.

CONCLUSIONS

Relapses frequently occur at sites of prior unirradiated disease in patients with MES. WLI may improve 2-year PFS, regardless of chemotherapy response. Further investigation of the role of MSI is warranted.

Risk factors for metastasis and poor prognosis of Ewing sarcoma: a population based study

Background

This study is to determine the risk factors for metastasis of Ewing sarcoma (ES) patients in SEER database. Then explore clinicopathological factors associated with poor prognosis. Furthermore, develop the nomogram to predict the probability of overall survival and cancer-specific survival

Methods

Thus, we collected clinicopathological data of ES patients in SEER database, and then used chi-square test and logistic regression to determine risk factors associated to metastasis. We also did survival analysis including Kaplan-Meier curve and Cox proportional hazard model to explore the risk factors associated to overall survival and cancer-specific survival, and then developed the nomogram to visualize and quantify the probability of survival.

Results

After statistics, we find that patients with older ages (11–20 years old: OR = 1.517, 95% confidence interval [CI] 1.033–2.228, p = 0.034; 21–30 years old: OR = 1.659. 95%CI 1.054–2.610, p = 0.029), larger tumor size (> 8 cm: OR = 1.914, 95%CI 1.251–2.928, p = 0.003), and pelvic lesions (OR = 2.492, 95%CI 1.829–3.395, p < 0.001) had a higher risk of metastasis. ROC curves showed higher AUC (0.65) of combined model which incorporate these three factors to predict the presence of metastasis at diagnosis. In survival analysis, patients with older ages (11–20 years: HR = 1.549, 95%CI 1.144–2.099, p = 0.005; 21–30 years: HR = 1.808, 95%CI 1.278–2.556, p = 0.001; 31–49 years: HR = 3.481, 95%CI 2.379–5.094, p < 0.001; ≥ 50 years: HR = 4.307, 95%CI 2.648–7.006, p < 0.001) , larger tumor size (5–8 cm: HR = 1.386, 95%CI 1.005–1.991, p = 0.046; > 8 cm: HR = 1.877, 95%CI 1.376–2.561, p < 0.001), black race (HR = 2.104, 95%CI 1.296–3.416, p = 0.003), and wider extension (regional: HR = 1.373, 95%CI 1.033–1.823, p = 0.029; metastatic: HR = 3.259, 95%CI 2.425–4.379, p < 0.001) were associated with worse prognosis. Chemotherapy was associated with better prognosis (HR = 0.466, 95%CI 0.290–0.685, p < 0.001). The nomogram which developed by training set and aimed to predict OS and CSS showed good consistency with actual observed outcomes internally and externally.

Conclusion

In conclusion, tumor size and primary site were associated with distant metastasis at diagnosis. Age, tumor size, primary site, tumor extent, and chemotherapy were associated with overall survival and cancer-specific survival. Nomogram could predict the probability of OS and CSS and showed good consistency with actual observed outcomes internally and externally.

Ewing Sarcoma in an Infant Metacarpal

We describe a case of Ewing sarcoma in the metacarpal of a 5-month-old male. After pain, erythema, and swelling of the hand failed to resolve with antibiotics, radiographs and magnetic resonance imaging raised suspicion for a neoplastic condition. Open biopsy confirmed the diagnosis of Ewing sarcoma and treatment with chemotherapy and surgical resection was initiated. Ewing sarcoma of the hand in a patient this young is an exceedingly rare diagnosis, which highlights the importance of a broad differential diagnosis when the treatments for more common conditions fail.

The relation of radiological tumor volume response to histological response and outcome in patients with localized Ewing Sarcoma

Background

Magnetic resonance imaging (MRI) is the modality of choice for local staging and response evaluation of Ewing sarcoma (EwS). Aim of this study was to determine the relevance of tumor volume response (TVR) in relation to histological response (HisRes) and survival, in order to evaluate if early modification of chemotherapy might be indicated in patients with inadequate TVR.

Methods

Three dimensional (3D)‐tumor volume data at diagnosis, during early induction phase (1‐3 courses of chemotherapy; n = 195) and/or late induction phase (4‐6 courses; n = 175) from 241 localized patients were retrospectively analyzed. A distinction was made between adequate response (reduction ≥67%) and inadequate response (reduction <67% or progression). Correlations between TVR, HisRes, event free survival (EFS), and overall survival (OS) were analyzed using chi‐square tests, log‐rank tests, and the Cox‐regression model.

Results

Early adequate TVR, noted in 41% of patients, did not correlate with EFS (P = 0.92) or OS (P = 0.38). During late induction phase 62% of patients showed an adequate TVR. EFS for patients with late adequate TVR was better (78%) than for those with inadequate late TVR (61%) (P = 0.01); OS was 80% and 69% (P = 0.26), respectively. No correlation was found between TVR and HisRes. Multivariate analysis showed that poor HisRes, pelvic location and late inadequate TVR were associated with poor outcome.

Conclusions

Early inadequate TVR does not predict adverse outcome; therefore, changing the treatment to second line chemotherapy is not indicated in case of inadequate early TVR. Late adequate TVR and good HisRes correlate with better EFS; patients with late inadequate TVR might benefit from augmented therapy.

Early recognition and diagnosis of Ewing sarcoma of the cervical spine

Ewing sarcoma of the cervical spine is a rare diagnosis. Early recognition and treatment of this condition improves survival. Reported is a case of a 20-year-old male patient who presented with increasing neck pain. Computed tomography and magnetic resonance imaging showed a mass with a primary differential diagnosis of Ewing sarcoma. As a result of mass effect and spinal cord compression, immediate medical intervention was deemed necessary to prevent neurologic deficits.

Diagnostic Accuracy of 18F-FDG PET/CT in the Staging and Assessment of Response to Chemotherapy in Children With Ewing Sarcoma

INTRODUCTION

The purpose of this study was to evaluate the potential role of fluorine-18 fluorodeoxyglucose (18F-FDG) positron-emission tomography/computed tomography (PET-CT) in the staging and assessment of chemotherapy response in Ewing sarcoma.

MATERIALS AND METHODS

For 13 patients with Ewing sarcoma, whole-body FDG PET-CT was assessed for site of primary disease, disease extent, and response to therapy. Chest CT, localized magnetic resonance imaging or CT of primary site, and bone scintigrams were evaluated for imaging features of the primary lesion and presence or absence of metastatic disease. Response to therapy was also assessed. Descriptive statistics are reported.

RESULTS

Nine patients (69%) presented metastatic disease. All metastatic lung lesions were detected by spiral CT, but some failed to be detected using FDG PET-CT. As regards bone lesions, both FDG PET-CT and bone scans were able to identify bone metastasis, but FDG PET-CT identified more lesions than bone scans. All PET-CT scans at the end of the neoadjuvant chemotherapy showed a decreased FDG uptake.

CONCLUSIONS

FDG PET-CT seems to be superior to bone scan in the detection of bone metastasis in all districts except skull bones. For pulmonary metastasis smaller than 7 mm, FDG PET-CT is less sensitive than CT. FDG PET-CT may have an important role in initial staging of Ewing sarcoma and subsequent evaluation of response to therapy.

Immunohistochemical analysis and prognostic significance of PD-L1, PD-1, and CD8+ tumor-infiltrating lymphocytes in Ewing's sarcoma family of tumors (ESFT)

Ewing's sarcoma family of tumors (ESFT) are aggressive neoplasms with scant tumor-infiltrating lymphocytes. We analyzed the immunohistochemical (IHC) expression of PD-L1 and PD-1 and their prognostic significance in clinically localized neoplasms in a cohort of 370 ESFT. Slides prepared from tissue microarrays were stained for PD-L1, PD-1, and CD8. Membranous/cytoplasmic staining over 5% of tumor cells was regarded as positive for PD-L1 and PD-1. Prognostic analysis was done considering only clinically localized tumors (n = 217). PD-L1 expression was present in 19% of ESFT, while PD-1 was expressed in 26%. Forty-eight percent of tumors were negative and 12% were positive for both PD-L1 and PD-1. Metastatic tumors displayed higher expression of PD-L1 (p < 0.0001). Histological subtypes were not correlated with PD-L1 or PD-1 positivity. ESFT with elevated proliferation index (Ki-67) were associated with higher PD-L1 expression (p = 0.049). Regarding prognosis, no significant association was found between PD-L1 expression and progression-free survival (PFS) or overall survival (OS), whereas lack of PD-1 expression in tumor cells was correlated with both poor PFS (p = 0.02) and poor OS (p = 0.004). Tumor-infiltrating CD8(+) T lymphocytes were observed in 15.4% of ESFT with informative results (347 tumors). No correlation was found between tumor-infiltrating CD8(+) T lymphocytes and ESFT histological subtypes, tumor location, or PD-1 and PD-L1 expression, nor with PFS (p = 0.473) or OS (p = 0.087). PD-L1 expression was not significantly related to prognosis. PD-1 was expressed in 26% of ESFT tumor cells and may have prognostic and therapeutic implications. CD8 expression in tumor-infiltrating lymphocytes was not related to prognosis.

Pencil beam scanned protons for the treatment of patients with Ewing sarcoma

BACKGROUND

Few data exist regarding the clinical outcome of patients with Ewing sarcoma (EWS) treated with pencil beam scanning proton therapy (PT). We report the outcome of children, adolescents and young adults (AYA) treated with PT at the Paul Scherrer Institute.

MATERIALS

Thirty-eight patients (median age, 9.9 years) received a median dose of 54.9 Gy(RBE) (where RBE is relative biologic effectiveness). Size of the tumor ranged from 1.7 to 24 cm. Most common primary site was axial/pelvic (n = 27; 71%). Four patients (11%) presented with metastases at diagnosis. Twenty (53%) patients had chemo-PT only. Median follow-up was 49.6 months (range, 9.2-131.7).

RESULTS

The 5-year actuarial rate of local control (LC), distant metastasis-free survival (DMFS), and overall survival (OS) were 81.5%, 76.4%, and 83.0%, respectively. All local recurrences occurred in field and in patients with nonextremity primaries. Six patients died, all of tumor progression. Age < 10 years was a favorable factor of borderline significance for LC (P = 0.05) and OS (P = 0.05), but was significant for DMFS (P = 0.003). Tumor volume <200 ml was a significant prognostic factors for DMFS (P = 0.03), but not for OS (P = 0.07). Metastasis at diagnosis was a strong predictor of local failure (P = 0.003). Only two grade 3 late toxicities were observed. The 5-year actuarial rate of grade 3 toxicity-free survival was 90.9%.

CONCLUSIONS

These preliminary data suggest that the outcomes of children and AYA with EWS are good and PT was well tolerated with few late adverse events. The local and distant tumor control for older patients with large pre-PT tumor volumes remains problematic.

Percent slope analysis of dynamic magnetic resonance imaging for assessment of chemotherapy response of osteosarcoma or Ewing sarcoma: systematic review and meta-analysis

OBJECTIVE

The objective of this systematic review is to provide an up-to-date and unprecedented summary of percent slope analysis of dynamic magnetic resonance imaging (MRI) for the preoperative evaluation of the chemotherapy response of osteosarcoma or Ewing sarcoma.

MATERIALS AND METHOD

Studies evaluating dynamic MRI for the preoperative evaluation of the chemotherapy response of osteosarcoma or Ewing sarcoma were systematically searched for in MEDLINE, EMBASE, and Web of Science. More than 60 % reduction of the slope of the time intensity curve derived from dynamic MRI was defined as a positive response. Pooled sensitivity and specificity for each study were calculated into 2 × 2 contingency tables. The DerSimonian-Laird random-effects method was used for determining the pooled diagnostic odds ratio and the area under curve (AUC) of the summary receiver operating characteristic (SROC) curve.

RESULTS

A total of six studies with 66 patients who fulfilled all of the inclusion criteria were considered for the meta-analysis. The pooled sensitivity and specificity were 0.73 (95 % CI, 0.54-0.88) and 0.83 (95 % CI, 0.67-0.94), respectively. A significant difference was found between the good and poor responders in the diagnostic odds ratio. The SROC curve showed that the AUC was 0.839, indicating diagnostic accuracy in estimating good therapy response.

CONCLUSION

The slope of the time intensity curve derived from dynamic MRI was useful for evaluating the histological response of patients to neoadjuvant chemotherapy in osteosarcoma or Ewing sarcoma.