Comparative evaluation of local control strategies in localized Ewing sarcoma of bone: a report from the Children's Oncology Group

Comprehensive radiotherapy for pediatric Ewing Sarcoma: Outcomes of a prospective proton study

BACKGROUND AND PURPOSE

Patients with Ewing Sarcoma (EWS) are treated with multimodality therapy which includes radiation therapy (RT) as an option for local control. We report on the efficacy after proton radiation therapy (PRT) to the primary site for localized and metastatic EWS.

MATERIALS AND METHODS

Forty-two children with EWS (33 localized, 9 metastatic) treated between 2007 and 2020 were enrolled on 2 prospective registry protocols for pediatric patients undergoing PRT. PRT was delivered by passive scatter (74 %), pencil-beam scanning (12 %) or mixed technique (14 %). Treated sites included the spine (45 %), pelvis/sacrum (26 %), skull/cranium (14 %), extraosseous (10 %), and chest wall (5 %). Median radiation dose was 54 Gy-RBE (range 39.6-55.8 Gy-RBE). Patients with metastatic disease received consolidative RT to metastatic sites (4 at the time of PRT to the primary site, 5 after completion of chemotherapy). Median follow-up time was 47 months after PRT.

RESULTS

The 4-year local control (LC), progression-free survival (PFS), and overall survival (OS) rates were 83 %, 71 %, and 86 %, respectively. All local failures (n = 6) were in-field failures. Tumor size ≥ 8 cm predicted for inferior 4-year LC (69 % vs 95 %, p = 0.04). 4-year PFS and OS rates were not statistically different in patients with localized versus metastatic disease (72 % vs 67 %, p = 0.70; 89 % vs 78 %, p = 0.38, respectively).

CONCLUSION

In conclusion, LC for pediatric patients with EWS treated with PRT was comparable to that of historical patients who received photon-RT. Tumor size ≥ 8 cm predicted increased risk of local failure. Patients with metastatic disease, including non-pulmonary only metastases, received radiation therapy to all metastatic sites and had favorable survival outcomes.

Primary Ewing sarcoma of the kidney mimicking cystic papillary renal cell carcinoma in an older patient: A case report

BACKGROUND

Ewing's sarcoma (ES) is a neuroectodermal tumor that typically occurs in the bones and soft tissues of children and young adults. Primary renal ES is rare; only a few cases and a small case series have been documented, and only four cases involved primary renal ES in older people (> 65 years old).

CASE SUMMARY

Herein, we describe the radiological and pathological features of primary renal ES in an older person. A 76-year-old man complained of poor oral intake and was found to have a large cystic renal mass with indistinct margins on computed tomography. Ultrasound-guided biopsy revealed that the tumor contained small round blue cells. The patient underwent a right radical nephrectomy. The tumor cells showed diffuse membranous CD99, and nuclear friend leukemia integration 1 transcription factor and NK2 Homeobox 2. Fluorescence in situ hybridization revealed EWSR1 translocation. Postoperatively, 18F-fluorodeoxyglucose positron emission tomography revealed no evidence of metastasis. The patient was diagnosed with primary renal ES. Six months following the surgery, local recurrence and distant metastasis were observed. Primary renal ES is rare and often lethal in older individuals. The specific imaging findings are unknown, and treatment protocols have not been standardized.

CONCLUSION

This case report describes the radiological and pathological features of primary renal ES in an older person.

Radiation therapy dose escalation achieves high rates of local control with tolerable toxicity profile in pediatric and young adult patients with Ewing sarcoma

BACKGROUND

Local control for patients with Ewing sarcoma (EWS) who present with large tumors are suboptimal when treated with standard radiation therapy (RT) doses of 54-55.8 Gy. The purpose of this study is to determine local control and toxicity of dose-escalated RT for tumors ≥8 cm (greatest diameter at diagnosis) in pediatric and young adult patients with EWS.

METHODS

Eligible patients ≤30 years old with newly diagnosed EWS ≥8 cm treated with definitive conformal or intensity modulated photon, or proton radiation therapy techniques were included. All patients in the study received dose-escalated RT doses. Outcomes included overall survival (OS), event-free survival (EFS), local failure rates, and toxicity.

RESULTS

Thirty-two patients were included, 20 patients presented with metastatic disease and 12 patients with localized disease. The median RT dose was 64.8 Gy (range, 59.4-69.4 Gy) with variability of doses to protect normal surrounding tissues. All patients received systemic chemotherapy. The 5-year OS and EFS for the cohort was 64.2% and 42%, respectively. The 5-year cumulative incidence of local failure was 6.6%. There were two combined local and distant failures with no isolated local failures. Twenty-nine patients experienced short term toxicity, 90% of those being radiation dermatitis. Twenty-seven patients experienced long-term toxicity, with only one experiencing grade 4 toxicity, a secondary malignancy after therapy.

CONCLUSION

This study demonstrates that definitive RT for pediatric and young adult patients with EWS ≥8 cm provides high rates of local control, while maintaining a tolerable toxicity profile.

Immunocompetent murine model of Ewing sarcoma reveals role for TGFβ inhibition to enhance immune infiltrates in Ewing tumors during radiation

Ewing sarcoma (ES) is an aggressive cancer diagnosed in adolescents and young adults. The fusion oncoprotein (EWSR1::FLI1) that drives Ewing sarcoma is known to downregulate TGFBR2 expression (part of the TGFβ receptor). Because TGFBR2 is downregulated, it was thought that TGFβ likely plays an inconsequential role in Ewing biology. However, the expression of TGFβ in the Ewing tumor immune microenvironment (TIME) and functional impact of TGFβ in the TIME remains largely unknown given the historical lack of immunocompetent preclinical models. Here, we use single-cell RNAseq analysis of human Ewing tumors to show that immune cells, such as NK cells, are the largest source of TGFβ production in human Ewing tumors. We develop a humanized (immunocompetent) mouse model of ES and demonstrate distinct TME signatures and metastatic potential in these models as compared to tumors developed in immunodeficient mice. Using this humanized model, we study the effect of TGFβ inhibition on the Ewing TME during radiation therapy, a treatment that both enhances TGFβ activation and is used to treat aggressive ES. Utilizing a trivalent ligand TGFβ TRAP to inhibit TGFβ, we demonstrate that in combination with radiation, TGFβ inhibition both increases ES immune cell infiltration and decreases lung metastatic burden in vivo . The culmination of these data demonstrates the value of humanized models to address immunobiologic preclinical questions in Ewing sarcoma and suggests TGFβ inhibition as a promising intervention during radiation therapy to promote metastatic tumor control.

Eflornithine as Postimmunotherapy Maintenance in High-Risk Neuroblastoma: Externally Controlled, Propensity Score-Matched Survival Outcome Comparisons

PURPOSE

Long-term survival in high-risk neuroblastoma (HRNB) is approximately 50%, with mortality primarily driven by relapse. Eflornithine (DFMO) to reduce risk of relapse after completion of immunotherapy was investigated previously in a single-arm, phase II study (NMTRC003B; ClinicalTrials.gov identifier: NCT02395666) that suggested improved event-free survival (EFS) and overall survival (OS) compared with historical rates in a phase III trial (Children Oncology Group ANBL0032; ClinicalTrials.gov identifier: NCT00026312). Using patient-level data from ANBL0032 as an external control, we present new analyses to further evaluate DFMO as HRNB postimmunotherapy maintenance.

PATIENTS AND METHODS

NMTRC003B (2012-2016) enrolled patients with HRNB (N = 141) after standard up-front or refractory/relapse treatment who received up to 2 years of continuous treatment with oral DFMO (750 ± 250 mg/m2 twice a day). ANBL0032 (2001-2015) enrolled patients with HRNB postconsolidation, 1,328 of whom were assigned to dinutuximab (ch.14.18) treatment. Selection rules identified 92 NMTRC003B patients who participated in (n = 87) or received up-front treatment consistent with (n = 5) ANBL0032 (the DFMO/treated group) and 852 patients from ANBL0032 who could have been eligible for NMTRC003B after immunotherapy, but did not enroll (the NO-DFMO/control group). The median follow-up time for DFMO/treated patients was 6.1 years (IQR, 5.2-7.2) versus 5.0 years (IQR, 3.5-7.0) for NO-DFMO/control patients. Kaplan-Meier and Cox regression compared EFS and OS for overall groups, 3:1 (NO-DFMO:DFMO) propensity score-matched cohorts balanced on 11 baseline demographic and disease characteristics with exact matching on MYCN, and additional sensitivity analyses.

RESULTS

DFMO after completion of immunotherapy was associated with improved EFS (hazard ratio [HR], 0.50 [95% CI, 0.29 to 0.84]; P = .008) and OS (HR, 0.38 [95% CI, 0.19 to 0.76]; P = .007). The results were confirmed with propensity score-matched cohorts and sensitivity analyses.

CONCLUSION

The externally controlled analyses presented show a relapse risk reduction in patients with HRNB treated with postimmunotherapy DFMO.

Association between local treatment modalities and event-free survival, overall survival, and local recurrence in patients with localised Ewing Sarcoma. Report from the Ewing 2008 trial

BACKGROUND

Local treatment is a crucial element in the standard of care for Ewing sarcoma (EWS). While systemic treatment is improved in randomised clinical trials, local treatment modalities are discussed controversially. We analysed the association between local therapy and event-free survival (EFS), overall survival (OS), and local recurrence (LR) in prospectively collected data of patients with localised EWS.

PATIENTS AND METHODS

We analysed data from the international Ewing 2008 study registered between 2009 and 2019 in 117 centres. After induction chemotherapy, patients received surgery, radiotherapy, or a combination thereof. We performed Cox regression, conducted propensity score-weighted sensitivity analysis, and performed subgroup analyses. Hazard ratios (HRs) and 95% confidence intervals are reported.

RESULTS

We included 863 patients with localised EWS (surgery alone: 331, combination therapy: 358, definitive radiotherapy: 174). In patients treated with combination therapy compared to surgery alone, EFS HR was 0.84 (0.57-1.24; p = 0.38), OS HR was 0.84 (0.57-1.23; p = 0.41), and LR HR was 0.58 (0.26-1.31; p = 0.19). Hazards of any event were increased in patients treated with definitive radiotherapy compared to surgery only, HR 1.53 (1.02-2.31; p = 0.04). Patients with poor responses to chemotherapy benefitted from combination therapy over definitive surgery with an EFS HR 0.49 (0.27-0.89; p = 0.02). Patients with pelvic tumours benefitted from combination therapy over surgery only regarding LR, HR 0.12 (0.02-0.72; p = 0.02).

CONCLUSION

Patients with poor responses to chemotherapy benefitted from radiotherapy added to surgery. In the whole group, radiotherapy alone as opposed to surgery alone increased the hazards of any event.

Special Issue: "Pediatric Orthopedic Malignancy: Types, Symptoms, and Treatment"

Pediatric orthopedic malignancies are extremely rare and require appropriate diagnosis and treatment by a multidisciplinary team [...].

Radiotherapy in bone sarcoma: the quest for better treatment option

Bone sarcomas are rare tumors representing 0.2% of all cancers. While osteosarcoma and Ewing sarcoma mainly affect children and young adults, chondrosarcoma and chordoma have a preferential incidence in people over the age of 40. Despite this range in populations affected, all bone sarcoma patients require complex transdisciplinary management and share some similarities. The cornerstone of all bone sarcoma treatment is monobloc resection of the tumor with adequate margins in healthy surrounding tissues. Adjuvant chemo- and/or radiotherapy are often included depending on the location of the tumor, quality of resection or presence of metastases. High dose radiotherapy is largely applied to allow better local control in case of incomplete primary tumor resection or for unresectable tumors. With the development of advanced techniques such as proton, carbon ion therapy, radiotherapy is gaining popularity for the treatment of bone sarcomas, enabling the delivery of higher doses of radiation, while sparing surrounding healthy tissues. Nevertheless, bone sarcomas are radioresistant tumors, and some mechanisms involved in this radioresistance have been reported. Hypoxia for instance, can potentially be targeted to improve tumor response to radiotherapy and decrease radiation-induced cellular toxicity. In this review, the benefits and drawbacks of radiotherapy in bone sarcoma will be addressed. Finally, new strategies combining a radiosensitizing agent and radiotherapy and their applicability in bone sarcoma will be presented.

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.

Case report: Primary pleural giant extraskeletal Ewing sarcoma in a child

Primary extraskeletal Ewing sarcoma (EES) is a rare small round cell malignancy that accounts for less than 1% of all sarcomas. It is found most commonly in the trunk and lower limbs and very rarely in the pleura and can be easily misdiagnosed in clinical practice. This study presents the case of an 11-year-old boy who presented to our hospital with no apparent cause of left shoulder pain for 6 months. On physical examination, tenderness was noted in the left chest wall and shoulder joint, which had a limited range of motion. Computed tomography (CT) and magnetic resonance imaging (MRI) of the chest revealed an irregular soft tissue mass in the upper left thorax, with a wide base attached to the adjacent pleura and bone destruction of the adjacent left first rib. The patient’s bone scan showed a dense focus of increased radiotracer accumulation in the left first rib. A subsequent CT-guided aspiration biopsy of the left pleural mass with histomorphology and immunohistochemical phenotyping led to a diagnosis of extraskeletal Ewing sarcoma. To inhibit tumor growth, alternating systemic chemotherapy cycles of vincristine, doxorubicin, and cyclophosphamide (VDC) and isocyclophosphamide and etoposide (IE) were administered at 3-week intervals. After completing three VDC and two IE cycles, the child’s condition was well and the pain in the left shoulder joint was relieved. However, a repeat MRI of the chest showed that the mass did not shrink.

Extraskeletal Ewing sarcoma presenting as an axillary mass with pulmonary metastases

Extraskeletal Ewing sarcoma (EES) is a tumour of rare variant of the Ewing sarcoma family of tumours. This family of tumours can have different features; however, these tumours are categorised on the basis of genetic translocation, specific molecular and immunohistochemical features. EES is seen commonly affecting young adults with poor prognosis and high mortality rates. It can be detected in various locations making its diagnosis more difficult. It can present with varied imaging features, often non-specific. However, imaging plays a vital role in the primary tumour assessment, local staging, preoperative management and surveillance. Management involves surgery with chemotherapy. Long-term prognosis in cases of metastatic disease is very poor. In literature, only three cases of axillary EES have been reported so far. Here, we report the fourth case of large EES originating in the left axillary region in a woman in her 20s. The patient was given neoadjuvant chemotherapy; however, the size of the tumour increased, which was later surgically treated with complete excision of the tumour. Unfortunately, the tumour metastasised to the lung for which the patient was irradiated. Afterwards, the patient presented to the emergency room with respiratory distress for which she was on ventilator support; sadly, the patient died after 1 week.

The clinical characteristics, novel predictive tool, and risk classification system for primary Ewing sarcoma patients that underwent chemotherapy: A large population-based retrospective cohort study

BACKGROUND

This study aims to determine the independent prognostic predictors of cancer-specific survival (CSS) in patients with primary Ewing sarcoma (ES) that underwent chemotherapy and create a novel prognostic nomogram and risk stratification system.

METHODS

Demographic and clinicopathologic characteristics related to patients with primary ES that underwent chemotherapy between 2000 and 2018 were extracted from the Surveillance, Epidemiology, and End Results (SEER) database. CSS was the primary endpoint of this study. First, independent prognostic predictors of CSS identified from univariate and multivariate Cox regression analyses were used to construct a prognostic nomogram for predicting 1-, 3-, and 5-year CSS of patients with primary ES that underwent chemotherapy. Then, calibration curves and receiver operating characteristic (ROC) curves were used to evaluate the nomogram's prediction accuracy, while decision curve analysis (DCA) was used to evaluate the nomogram's clinical utility. Finally, a mortality risk stratification system was constructed for this subpopulation.

RESULTS

A total of 393 patients were included in this study. Age, tumor size, bone metastasis, and surgery were independent prognostic predictors of CSS. The calibration curves, ROC, and DCA showed that the nomogram had excellent discrimination and clinical value, with the 1-, 3-, and 5-year AUCs higher than 0.700. Moreover, the mortality risk stratification system could effectively divide all patients into three risk subgroups and achieve targeted patient management.

CONCLUSIONS

Based on the SEER database, a novel prognostic nomogram for predicting 1-, 3-, and 5- year CSS in patients with primary ES that underwent chemotherapy has been constructed and validated. The nomogram showed relatively good performance, which could be used in clinical practice to assist clinicians in individualized treatment strategies.

Spinal tumours: recommendations of the Polish Society of Spine Surgery, the Polish Society of Oncology, the Polish Society of Neurosurgeons, the Polish Society of Oncologic Surgery, the Polish Society of Oncologic Radiotherapy, and the Polish Society of Orthopaedics and Traumatology

PURPOSE

The purpose of these recommendations is to spread the available evidence for evaluating and managing spinal tumours among clinicians who encounter such entities.

METHODS

The recommendations were developed by members of the Development Recommendations Group representing seven stakeholder scientific societies and organizations of specialists involved in various forms of care for patients with spinal tumours in Poland. The recommendations are based on data yielded from systematic reviews of the literature identified through electronic database searches. The strength of the recommendations was graded according to the North American Spine Society's grades of recommendation for summaries or reviews of studies.

RESULTS

The recommendation group developed 89 level A-C recommendations and a supplementary list of institutions able to manage primary malignant spinal tumours, namely, spinal sarcomas, at the expert level. This list, further called an appendix, helps clinicians who encounter spinal tumours refer patients with suspected spinal sarcoma or chordoma for pathological diagnosis, surgery and radiosurgery. The list constitutes a basis of the network of expertise for the management of primary malignant spinal tumours and should be understood as a communication network of specialists involved in the care of primary spinal malignancies.

CONCLUSION

The developed recommendations together with the national network of expertise should optimize the management of patients with spinal tumours, especially rare malignancies, and optimize their referral and allocation within the Polish national health service system.

Ewing's Sarcoma of Mandible: Practical Approach to a Challenging Case

As a rare entity, sarcomas of the head and neck are challenging cases. In this paper, we represent a unique case of Ewing sarcoma of mandible, serving as an example of multidisciplinary team importance in a developing country.

Sacral Ewing sarcoma with rib, lung, and multifocal skull metastases: A rare case report and review of treatments

Ewing sarcoma (ES) rarely derives from the sacrum or mobile spine. The discovery of primary ES with multimetastatic involvements is exceedingly less frequent in clinical practice. A 23-year-old man with initial primary sacral ES developed metastases of rib, lung, and multifocal skull after receiving surgical intervention and series of adjuvant therapies. We provide this very rare case consisting of its clinical features, imaging findings, treatments, and outcomes. Therapeutic modalities of ES are also reviewed in previous published articles. The prognosis of metastatic ES remains dismal; effective therapeutic modalities for ES require multidisciplinary collaboration, with more high-quality clinical trials to promote the optimal protocols.

Ewing sarcoma of the ileum with wide multiorgan metastases: A case report and review of literature

BACKGROUND

Ewing sarcoma (ES) is an aggressive small round cell tumor that usually occurs in younger children and young adults but rarely in older patients. Its occurrence in elderly individuals is rare. ES of the ileum with wide multiorgan metastases is rarely reported and difficult to distinguish radiologically from other gastrointestinal tract tumors.

CASE SUMMARY

A 53-year-old man presented with right lower quadrant pain for 2 wk. Computed tomography results showed a heterogeneous mass within the ileum and widespread multiorgan metastases. This mass was biopsied, and pathological examination of the resected specimen revealed features consistent with an extraskeletal ES.

CONCLUSION

This case emphasizes the importance of recognizing this rare presentation in the small intestine to broaden the differential diagnosis of adult intraabdominal tumors.

Multimodality treatment of pediatric Ewing sarcoma: A single-center 10-year analysis of outcomes

BACKGROUND

Ewing sarcoma, a malignancy originating from the bone or soft tissues most commonly diagnosed in adolescents, requires multimodality therapy. Although both surgical resection and radiation therapy are effective local control modalities, there are limited data comparing outcomes in patients treated with surgery versus radiation. We sought to determine whether there were differences in 5-year local failure-free survival, event-free survival, and overall survival based on the modality used for local control.

METHODS

Patients treated for Ewing sarcoma at a single tertiary pediatric hospital between 2010 and 2020 were included for retrospective analysis. Patient and tumor demographics, treatment information, and patient response to therapies were collected from the medical record. Outcome measures were local failure-free survival, event-free survival, and overall survival at 5 years from diagnosis.

RESULTS

Sixty-one patients met inclusion criteria. All patients received chemotherapy, and 68.9% of patients presented with localized disease. Of these, 23.8% were treated with radiation alone; the remaining 76.2% underwent resection ± radiation. A total of 52.4% of patients with localized disease achieved R0 resection. Only 3 patients experienced local progression; there was no difference between treatment groups. There was no significant association between local control modality and event-free survival or overall survival in patients with localized disease, regardless of margin status.

CONCLUSION

There was no significant difference in 5-year local failure-free survival, event-free survival, or overall survival in Ewing sarcoma patients treated with radiation versus surgery ± radiation, regardless of whether or not R0 resection was achieved. Future directions include a multi-institutional study to allow for further subgroup analysis and increased sample size.

Radiation Therapy Dose Escalation in Unresectable Ewing Sarcoma: Final Results of a Phase 3 Randomized Controlled Trial

PURPOSE

Our aim was to assess the effect of radiation therapy (RT) dose escalation on outcomes in surgically unresectable Ewing sarcoma (ES)/primitive neuroectodermal tumor (PNET).

METHODS AND MATERIALS

Patients with nonmetastatic unresectable ES/PNET (excluding intracranial/chest wall) receiving vincristine, doxorubicin, cyclophosphamide, ifosfamide, and etoposide chemotherapy, planned for definitive RT, were accrued in this single-institution, open-label, phase 3 randomized controlled trial. Randomization was between standard dose RT (SDRT; 55.8 Gy/31 fractions/5 days a week) versus escalated dose RT (EDRT; 70.2 Gy/39 fractions/5 days a week) with a primary objective of improving local control (LC) by 17% (65%-82%). Secondary outcomes included disease-free survival (DFS), overall survival (OS), and functional outcomes by Musculoskeletal Tumor Society score.

RESULTS

Between April 2005 and December 2015, 95 patients (SDRT 47 and EDRT 48) with a median age of 17 years (interquartile range, 13-23 years) were accrued. The majority of patients were male (59%). Pelvis was the most common site of primary disease (n = 60; 63%). The median largest tumor dimension (9.7 cm) and the median maximum standardized uptake value (8.2) on pretreatment fluorodeoxyglucose positron emission tomography-computed tomography were similar. At a median follow-up of 67 months, the 5-year LC, DFS, and OS for the entire cohort was 62.4%, 41.3%, and 51.9%, respectively. The 5-year LC was significantly better in EDRT compared with SDRT (76.4% vs 49.4%; P = .02). The differences in DFS and OS at 5 years (for EDRT vs SDRT) did not achieve statistical significance (DFS 46.7% vs 31.8%; P = .22 and OS 58.8% vs 45.4%; P = .08). There was a higher incidence of Radiation Therapy Oncology Group grade >2 skin toxic effects (acute) in the EDRT arm (10.4% vs 2.1%; P = .08) with excellent functional outcomes (median Musculoskeletal Tumor Society score = 29) in both arms.

CONCLUSIONS

EDRT results in improved LC with good functional outcomes without a significant increase in toxic effects. Radiation dose escalation should be considered for surgically unresectable nonmetastatic ES/PNET.

Impact of local treatment modality on overall- and disease-specific survival for nonmetastatic pelvic and sacral Ewing sarcoma

PURPOSE

The ideal local treatment modality for pelvic and sacral Ewing sarcoma (EWS) is controversial.

METHODS

We present the data from the American College of Surgeon's National Cancer Database (NCDB) and the National Cancer Institute's Surveillance, Epidemiology and End Result (SEER) database to investigate the impact of local treatment modalities on survival for nonmetastatic pelvic and sacral Ewing sarcoma. Local treatment includes "surgery," "radiation," and a combination of "surgery and radiation."

RESULTS

A total of 235 cases from SEER and 285 cases from NCDB were analyzed. Patients with "localized" stage (intraosseous) in the SEER database did not show any statistically significant difference in the disease-specific survival (DSS) for any of the local treatment modalities. Similar findings were observed for overall survival among patients with American Joint Committee on Cancer (AJCC) stage II and III in the NCDB database. However, patients with nonmetastatic disease, particularly regional disease (extraosseous), showed improved DSS with surgery only, in the SEER.

CONCLUSION

We found similar levels of efficacy for different treatment modalities for patients with intraosseous and AJCC II and III pelvic and sacral EWS. "Radiotherapy" is the most common local treatment modality employed in the United States. A prospective, randomized controlled trial with a direct head-to-head comparison is needed for a definitive conclusion.

Extraosseous Ewing sarcoma in children and adolescents: A retrospective series from a referral pediatric oncology center

BACKGROUND

Extraosseous Ewing sarcoma is a rare entity and less is known about its clinical behavior and optimal treatment than for its counterpart in bone. This study is a retrospective analysis on a cohort of patients <21 years treated according to a "soft tissue sarcoma approach."

METHODS

The "extraosseous" origin of the tumor was established on radiological findings, based on the lack of any bone involvement. Patients were treated using a multimodality approach including surgery, radiotherapy, and chemotherapy. All patients received chemotherapy with alkylating agents and anthracyclines for 25 weeks (nine courses). Radiotherapy (45-54.8 Gy) was required for all cases except those who had an initial R0 resection of tumors smaller than 5 cm.

RESULTS

Fifty-seven patients (age 2-20 years, median 14) were treated from 1990 to 2020. Ten-year event-free survival (EFS) and overall survival (OS) were 77.5% and 85.5% in patients with localized disease, and 11.1% and 29.6% in those with metastatic disease (p < .001) (follow-up 5-349 months, median 107 months). In patients with localized disease, the most recent IVADo-IVE regimen achieved excellent survivals, that is, 10-year EFS 95.5%.

CONCLUSIONS

Our study showed that satisfactory results were achieved in patients with localized extraosseous Ewing sarcoma treated with a tailored approach derived from soft tissue sarcoma protocols, which was less intensive and shorter as compared to the standards utilized for the management of bone Ewing sarcoma. Our study suggests that the extraskeletal site might be considered as a variable to stratify patients and modulate treatment intensity accordingly in Ewing sarcoma protocol.

A Nomogram for Predicting Cancer-Specific Survival of Osteosarcoma and Ewing's Sarcoma in Children: A SEER Database Analysis

Background

Osteosarcoma (OSC) and Ewing's sarcoma (EWS) are children's most common primary bone tumors. The purpose of the study is to develop and validate a new nomogram to predict the cancer-specific survival (CSS) of childhood OSC and EWS.

Methods

The clinicopathological information of all children with OSC and EWS from 2004 to 2018 was downloaded from the Surveillance, Epidemiology, and End Results (SEER) database. Univariate and multivariate Cox regression analyses were used to screen children's independent risk factors for CSS. These risk factors were used to construct a nomogram to predict the CSS of children with OSC and EWS. A series of validation methods, including calibration plots, consistency index (C-index), and area under the receiver operating characteristic curve (AUC), were used to validate the accuracy and reliability of the prediction model. Decision curve analysis (DCA) was used to validate the clinical application efficacy of predictive models. All patients were divided into low- and high-risk groups based on the nomogram score. Kaplan-Meier curve and log-rank test were used to compare survival differences between the two groups.

Results

A total of 2059 children with OSC and EWS were included. All patients were randomly divided into training cohort 60% (N = 1215) and validation cohort 40% (N = 844). Univariate and multivariate analysis suggested that age, surgery, stage, primary site, tumor size, and histological type were independent risk factors. Nomograms were established based on these factors to predict 3-, 5-, and 8-years CSS of children with OSC and EWS. The calibration plots showed that the predicted value was highly consistent with the actual value. In the training cohort and validation cohort, the C-index was 0.729 (0.702–0.756) and 0.735 (0.702–0.768), respectively. The AUC of the training cohort and the validation cohort also showed similar results. The DCA showed that the nomogram had good clinical value.

Conclusion

We constructed a new nomogram to predict the CSS of OSC and EWS in children. This predictive model has good accuracy and reliability and can help doctors and patients develop clinical strategies.

Systemic Treatment of Ewing Sarcoma: Current Options and Future Perspectives

Ewing sarcoma (ES) is an uncommon malignant neoplasm, mostly affecting young adults and adolescents. Surgical excision, irradiation, and combinations of multiple chemotherapeutic agents are currently used as a multimodal strategy for the treatment of local and oligometastatic disease. Although ES usually responds to the primary treatment, relapsed and primarily refractory disease remains a difficult therapeutic challenge. The growing understanding of cancer biology and the subsequent development of new therapeutic strategies have been put at the service of research in recurrent and refractory ES, generating a great number of ongoing studies with compounds that could find superior clinical outcomes in the years to come. This review gathers the current available information on the treatment and clinical investigation of ES and aims to be a point of support for future research.

Primary Ewing sarcoma/peripheral primitive neuroectodermal tumors in the cranial bone and mobile spine: what is the difference?

BACKGROUND

Primary Ewing sarcoma (ES)/peripheral primitive neuroectodermal tumors (pPNETs) are aggressive bone tumors that rarely occur in the axial skeleton, including the cranial bone and mobile spine. The purpose of this study was to investigate whether there were any differences in patient characteristics, treatment strategies, and outcomes between patients with ES/pPNETs of the cranial bone and those with ES/pPNETs of the mobile spine.

METHODS

A retrospective study was performed on 33 patients with ES/pPNETs who had been surgically treated and pathologically confirmed at our institution between 2010 and 2020. Patient characteristics were compared using Fisher exact tests or independent t tests. Survival rates were estimated via Kaplan-Meier survival analysis and compared using log-rank tests.

RESULTS

Thirteen patients had ES/pPNETs of the cranial bone (39.4%), while 20 patients had ES/pPNETs of the mobile spine (60.6%). Patients with ES/pPNETs of the cranial bone had a younger mean age (14.8 vs 22.6 years; p = 0.047) and longer mean disease duration (2.5 vs 1.9 months; p = 0.008) compared with those of patients with ES/pPNETs of the mobile spine. Kaplan-Meier analysis showed that gross total resection (GTR) and radiotherapy resulted in a longer median survival time. The overall survival rates and progression-free survival rates of patients with ES/pPNETs of the cranial bone versus those of the mobile spine were not significantly different (p = 0.386 and p = 0.368, respectively).

CONCLUSIONS

Patients with ES/pPNETs of the cranial bone were younger compared to patients with ES/pPNETs of the mobile spine. There was no significant difference in the prognosis of patients with ES/pPNETs of the cranial bone versus those of the mobile spine. Taken together, our findings suggest that GTR and radiotherapy offer the best prognosis for improved long-term survival.

Extraskeletal Ewing sarcoma in children, adolescents, and young adults. An analysis of three prospective studies of the Cooperative Weichteilsarkomstudiengruppe (CWS)

BACKGROUND

We have analyzed the outcome of patients with localized extraskeletal Ewing sarcoma (EES) treated in three consecutive Cooperative Weichteilsarkomstudiengruppe (CWS) soft tissue sarcoma (STS) studies: CWS-91, CWS-96, and CWS-2002P.

METHODS

Patients were treated in CWS-91 with four- (vincristine, dactinomycin, doxorubicin, and ifosfamide [VAIA] or cyclophosphamide [VACA II]) or five-drug (+etoposide [EVAIA]) cycles, in CWS-96 they were randomly assigned to receive VAIA or CEVAIE (+carboplatin and etoposide), and in CWS-2002P with VAIA III plus optional maintenance therapy (MT) with cyclophosphamide and vinblastine. Local therapy consisted of resection and/or radiotherapy (RT).

RESULTS

Two hundred forty-three patients fulfilled the eligibility criteria. The 5-year event-free survival (EFS) and overall survival (OS) were 63% (95% confidence interval [CI] 57-69) and 73% (95% CI 67-79), respectively. The 5-year EFS by study was 64% (95% CI 54-74) in CWS-91, 57% (95% CI 48-66) in CWS-96, and 79% (95% CI 67-91) in CWS-2002P (n.s.). The 5-year OS was 72% (95% CI 62-82) in CWS-91, 70% (95% CI 61-79) in CWS-96, and 86% (95% CI 76-96) in CWS-2002P (n.s.). In CWS-96, 5-year EFS and OS in the VAIA arm versus the CEVAIE were 65% (95% CI 52-81) versus 55% (95% CI 39-76) log-rank p = .13, and 85% (95% CI 75-96) versus 61% (95% CI 45-82), log-rank p = .09.

CONCLUSION

Our analysis provides interesting information on the treatment and specificities of EES, which can be useful for a better understanding of this rare entity and should be considered in the development of future clinical trials for Ewing sarcoma defined as FET-ETS fusion positive tumors.

Adolescent-adult nonmetastatic Ewing sarcoma-Experience from a large developing country

BACKGROUND

Outcome and toxicity data in adolescent-adult Ewing sarcoma (AA-ES) patients are sparse and merits exploration.

METHODS

Histopathologically confirmed, nonmetastatic AA-ES patients, who received standard institutional combination chemotherapy regimen (Ewing's family of tumors-2001 [EFT-2001]) comprising of ifosfamide plus etoposide and vincristine, doxorubicin plus cyclophosphamide, lasting a total of 12 months between 2013 and 2018, were analyzed for treatment-related toxicities, event-free survival (EFS), and overall survival (OS).

RESULTS

There were 235 patients (primary safety cohort [PSC]) with median age of 23 (15-61) years; 159 (67.7%) were males, 155 (65.9%) had skeletal primary and 114 (48.5%) had extremity tumors. One hundred ninety-six (83.4%) were treatment naïve (primary efficacy cohort [PEC]) and of these 119 (60.7%) had surgery. In PEC, at a median follow-up of 36.4 (interquartile range [IQR] 20-55) months, estimated 3-year EFS and OS were 67.3% (95% CI 60.3-75.1%) and 91.1% (95% CI 86.7-95.7%), respectively. Of these, 158 (80.6%) complying with intended treatment, at a median follow-up of 39 (IQR 26-57) months had an estimated 3-year EFS of 68.2% (95% CI 60.3-76.1%). In multivariable analysis, good prognostic factors included longer symptom(s) duration (HR 0.93, 95% CI 0.86-0.994), ≥99% necrosis (HR 0.30, 95% CI 0.11-0.77), and treatment completion (HR 0.32, 95% CI 0.14-0.74). Among PSC, grade 3-4 toxicities were febrile neutropenia (119, 50.6%), anemia (130, 55.3%), peripheral neuropathy (37, 15.7%), with three (1.3%) chemo-toxic deaths.

CONCLUSIONS

The outcomes of AA nonmetastatic ES patients treated with EFT-2001 regimen were comparable to those reported by others, with acceptable toxicity. This regimen can be considered a standard of care in AA-ES.

Ewing family tumors of the appendicular skeleton: a retrospective analysis of prognostic factors

PURPOSE

Authors retrospectively analyzed possible prognostic factors in a series of patients affected by Ewing sarcoma of extremities (eEWS) and treated over a 20-year period at a single institution.

METHODS

Between 1997 and 2017, 88 bone eEWS were treated at our institution. Staging, age, gender, tumoral volume, local treatment, surgical margins, post-ChT necrosis were investigated for prognostic correlation with overall survival (OS) and event-free survival (EFS). Median follow-up was 74 months (1-236).

RESULTS

Staging of disease correlated with OS (81% vs 59%, p = 0.01) and not with EFS (68% vs 57%, p = 0.28) in localized vs metastatic eEWS at presentation. Age ≥ 14 years (p = 0.002) and volume ≥ 100 cm3 (p = 0.04) were significant negative prognostic factors. No difference was found in local treatment: OS was 76% vs 63% (p = 0.33), while EFS was 68% vs 49% (p = 0.06) after surgery alone or surgery + radiotherapy, respectively. Regarding surgical margins, OS was 76% vs 38% (p = 0.14), and EFS was 65% vs 33% (p = 0.14) in adequate vs not adequate, respectively. OS was 86% and 68% in good and poor responders, respectively (p = 0.13).

CONCLUSION

In eEWS, metastatic disease at presentation, age > 14 years and tumoral volume > 100 cm³ are negative prognostic factors. Intensified adjuvant ChT can improve prognosis in poor responders and metastatic patients.

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.

Ewing Sarcoma-Diagnosis, Treatment, Clinical Challenges and Future Perspectives

Ewing sarcoma, a highly aggressive bone and soft-tissue cancer, is considered a prime example of the paradigms of a translocation-positive sarcoma: a genetically rather simple disease with a specific and neomorphic-potential therapeutic target, whose oncogenic role was irrefutably defined decades ago. This is a disease that by definition has micrometastatic disease at diagnosis and a dismal prognosis for patients with macrometastatic or recurrent disease. International collaborations have defined the current standard of care in prospective studies, delivering multiple cycles of systemic therapy combined with local treatment; both are associated with significant morbidity that may result in strong psychological and physical burden for survivors. Nevertheless, the combination of non-directed chemotherapeutics and ever-evolving local modalities nowadays achieve a realistic chance of cure for the majority of patients with Ewing sarcoma. In this review, we focus on the current standard of diagnosis and treatment while attempting to answer some of the most pressing questions in clinical practice. In addition, this review provides scientific answers to clinical phenomena and occasionally defines the resulting translational studies needed to overcome the hurdle of treatment-associated morbidities and, most importantly, non-survival.

Current Status of Management and Outcome for Patients with Ewing Sarcoma

Ewing sarcoma is the second most common bone sarcoma in children after osteosarcoma. It is a very aggressive malignancy for which systemic treatment has greatly improved outcome for patients with localized disease, who now see survival rates of over 70%. However, for the quarter of patients presenting with metastatic disease, survival is still dismal with less than 30% of patients surviving past 5 years. Patients with disease relapse, local or distant, face an even poorer prognosis with an event-free 5-year survival rate of only 10%. Unfortunately, Ewing sarcoma patients have not yet seen the benefit of recent years' technical achievements such as next-generation sequencing, which have enabled researchers to study biological systems at a level never seen before. In spite of large multinational studies, treatment of Ewing sarcoma relies entirely on chemotherapeutic agents that have been largely unchanged for decades. As many promising modern therapies, including monoclonal antibodies, small molecules, and immunotherapy, have been disappointing to date, there is no clear candidate as to which drug should be investigated in the next large-scale clinical trial. However, the mechanisms driving tumor development in Ewing sarcoma are slowly unfolding. New entities of Ewing-like tumors, with fusion transcripts that are related to the oncogenic EWSR1-FLI1 fusion seen in the majority of Ewing tumors, are being mapped. These tumors, although sharing much of the same morphologic features as classic Ewing sarcoma, behave differently and may require a different treatment. There are also controversies regarding local treatment of Ewing sarcoma. The radiosensitive nature of the disease and the tendency for Ewing sarcoma to arise in the axial skeleton make local treatment very challenging. Surgical treatment and radiotherapy have their pros and cons, which may give rise to different treatment strategies in different centers around the world. This review article discusses some of these controversies and reproduces the highlights from recent publications with regard to diagnostics, systemic treatment, and surgical treatment of Ewing sarcoma.

Indeterminate pulmonary nodules are not associated with worse overall survival in Ewing Sarcoma

AIM

Lung metastases are a negative prognostic factor in Ewing sarcoma, however, the incidence and significance of sub-centimetre pulmonary nodules at diagnosis is unclear. The aims of this study were to (1): determine the incidence of indeterminate pulmonary nodules (IPNs) in patients diagnosed with Ewing sarcoma (2); establish the impact of IPNs on overall and metastasis-free survival and (3) identify patient, oncological and radiological factors that correlate with poorer prognosis in patients that present with IPNs on their staging chest CT.

MATERIALS & METHODS

Between 2008 and 2016, 173 patients with a first presentation of Ewing sarcoma of bone were retrospectively identified from an institutional database. Staging and follow-up chest CTs for all patients with IPN were reviewed by a senior radiologist. Clinical and radiologic course were examined to determine overall- and metastasis-free survival for IPN patients and to identify demographic, oncological or nodule-specific features that predict which IPN represent true lung metastases.

RESULTS

Following radiologic re-review, IPN were found in 8.7% of patients. Overall survival for IPN patients was comparable to those with a normal staging chest CT (2-year overall survival of 73.3% [95% CI 43.6-89] and 89.4% [95% CI 81.6-94], respectively; p = 0.34) and was significantly better than for patients with clear metastases (46.0% [95% CI 31.9-59]; p < 0.0001). Similarly, there was no difference in metastasis-free survival between 'No Metastases' and 'IPN' patients (p = 0.16). Lung metastases developed in 40% of IPN patients at a median 9.6 months. Reduction of nodule size on neoadjuvant chemotherapy was associated with worse overall survival in IPN patients (p = 0.0084).

CONCLUSION

IPN are not uncommon in patients diagnosed with Ewing sarcoma. In this study, we were unable to detect a difference in overall- or metastasis-free survival between patients with IPN at diagnosis and patients with normal staging chest CTs.

Management of sarcomas in children, adolescents and adults: Interactions in two different age groups under the umbrellas of GSF-GETO and SFCE, with the support of the NETSARC+ network

Sarcomas are a rare heterogeneous group of malignant neoplasms that can arise in almost any anatomic site and any age. Close collaboration among adult and pediatric cancer specialists in the management of these tumors is of foremost importance. In this review, we present the current multidisciplinary organization in care of patients with sarcoma in France and we review the main advances made in the last decades in systemic and radiotherapy treatment in the main sarcoma types diagnosed in children, adolescents and young adults (AYA), thanks to the international collaboration.

Mithramycin A Radiosensitizes EWS:Fli1+ Ewing Sarcoma Cells by Inhibiting Double Strand Break Repair

PURPOSE

The oncogenic EWS:Fli1 fusion protein is a key transcriptional mediator of Ewing sarcoma initiation, progression, and therapeutic resistance. Mithramycin A (MithA) is a potent and specific inhibitor of transcription mediated by the EWS:Fli1. We tested the hypothesis that pretreatment with MithA could selectively radiosensitize EWS:Fli1⁺ tumor cells by altering the transcriptional response to radiation injury.

METHODS AND MATERIALS

A panel of 4 EWS:Fli1⁺ and 3 EWS:Fli1^- Ewing sarcoma cell lines and 1 nontumor cell line were subjected to MithA dose-response viability assays to determine the relative potency of MithA in cells possessing or lacking the EWS:Fli1 fusion. Radiosensitization by MithA was evaluated by clonogenic survival assays in vitro and in a murine xenograft model. DNA damage was evaluated by comet assay and γ-H2Ax flow cytometry. Immunoblotting, flow cytometry, and reverse-transcription, polymerase chain reaction were used to evaluate DNA damage-induced signaling and repair processes and apoptosis.

RESULTS

We found that MithA alone could potently and selectively inhibit the growth of EWS:Fli1⁺ tumor cells, but not cells lacking this fusion. Pretreatment with MithA for 24 hours before irradiation significantly reduced clonogenic survival in vitro and delayed tumor regrowth in vivo, prolonging survival of EWS:Fli1⁺ tumor-bearing mice. Although MithA did not increase the level of DNA double-strand breaks, mechanistic studies revealed that MithA pretreatment selectively inhibited DNA double-strand break repair through downregulation of EWS:Fli1-mediated transcription, leading to tumor cell death by apoptosis.

CONCLUSIONS

Our data indicate that MithA is an effective radiosensitizer of EWS:Fli1⁺ tumors and may achieve better local control at lower doses of radiation.

Primary Ewing Sarcoma/Primitive Neuroectodermal Tumor of the Kidney: The MD Anderson Cancer Center Experience

Limited information exists on the clinical behavior of the Ewing sarcoma family of tumors (ESFT) of the kidney. We reviewed the records of 30 patients (aged 8-69 years) with ESFT of the kidney seen at our institution between 1990 and 2013. We analyzed the event-free survival (EFS) and overall survival (OS) for associations with patient demographics, disease group, tumor size, tumor thrombus, and treatment. Six patients (20%) had tumors confined to the kidney (Group I), seven (23.3%) had local tumor extension beyond the kidney (Group II), and 17 (56.7%) had distant metastasis at diagnosis (Group III). Twenty-five (83.3%) patients underwent radical (19 upfront, five delayed) or partial (one upfront) nephrectomy, 25 (83.3%) chemotherapy and four (13.3%) radiotherapy. The 4-year EFS and OS were 43% (95% CI, 26-61%) and 63% (95% CI, 46-81%), respectively. EFS and OS were significantly associated with disease group and chemotherapy (p < 0.039). The presence of tumor thrombus in renal vein and/or inferior vena cava was associated with worse EFS (p = 0.053). Patients with disease confined to the kidney treated with nephrectomy and adjuvant chemotherapy have favorable outcomes. Local tumor extension beyond the kidney, tumor thrombus, and distant metastasis are unfavorable factors that warrant intensification or novel approaches of therapy.

Challenges in the management of localized Ewing sarcoma in a developing country

Survival in pediatric Ewing sarcoma (ES) lags in low- and middle-income countries (LMICs). This study analyzed factors contributing to a lower outcome in an LMIC center. A retrospective case review of children with localized ES treated from January 2011 till December 2017 was performed. Neoadjuvant chemotherapy with alternating cycles of vincristine, doxorubicin, cyclophosphamide; and ifosfamide, etoposide was administered 3-weekly for 48 weeks. Reassessment was planned for week 12, followed by local therapy (surgery/radiotherapy or both) tailed by adjuvant chemotherapy. Forty-eight patients with mean age 8 years (range: 0.7-14) were evaluated. Extremity and central axis tumors were seen in 25 (52%) and 23 (48%) patients. Three patients died of neutropenic sepsis and five abandoned therapy. Local therapy included primary surgery, radiotherapy and a combination of surgery and radiotherapy in 7 (16%), 20 (45%) and 17 (39%) patients. The 3-year event-free survival (EFS) and disease-free survival (DFS) for the cohort were 47.7 ± 11% and 57.6 ± 11.2%. Time to local therapy >16 weeks was associated with inferior DFS vs. local therapy administered within 16 weeks [46.6 ± 12.4 vs. 63.9 ± 19.4, p=.046]. Older age, axial site, large size and incomplete surgical resection did not predict relapse/progression. Patients who received wide local excision, as local therapy, had 100% DFS. Coordinated efforts to ensure timely therapy can improve outcome in pediatric ES. Abandonment and treatment-related mortality (TRM) are additional challenges that need to be tackled in LMICs.

Outcome of multidisciplinary treatment of peripheral primitive neuroectodermal tumor

Peripheral primitive neuroectodermal tumors (PNETs) constitute very rare and aggressive malignancies. To date, there are no standard guidelines for management of peripheral PNETs due to the paucity of cases arising in various body sites. Therapeutic approach is derived from Ewing sarcoma family, which currently remains multimodal. Our study retrospectively analyzed 86 PNET patients from February 1, 1998 to February 1, 2018 at Peking Union Medical College Hospital with an additional 75 patients from review of literature. The clinicopathologic and treatment plans associated with survival was investigated. Surgery, chemotherapy, female sex, small tumor size, no lymph node metastasis, R0 surgical resection, (vincristine + doxorubicin + cyclophosphamide)/(isophosphamide + etoposide) regimen, and more than 10 cycles of chemotherapy were associated with improved overall survival in univariate analysis. Surgery, more than 10 cycles of chemotherapy, and small tumor size were independent prognostic factors for higher overall survival. Our data indicates that multimodal therapy is the mainstay therapeutic approach for peripheral PNET.

Median Sacral Artery Rupture as a Complication of Posterior-Only Approach of L4 Total En Bloc Spondilectomy: A Case Report

CASE

A 6-year-old patient with Ewing sarcoma at L4 who was treated with total en bloc spondilectomy (TES) through a posterior-only approach. During the dissection of the anterior L4 body, there was uncontrollable bleeding from an unknown origin, which needed packing, massive transfusion, and urgent laparotomy. A median sacral artery (MSA) rupture was identified as the cause of this massive bleeding. Eventually, the patient was successfully stabilized.

CONCLUSIONS

To our knowledge, this is the first reported intraoperative bleeding of the MSA related to a lumbar TES through posterior-only approach. This life-threatening complication should be considered when planning for this type of surgery.

The Role of Tyrosine Kinases as a Critical Prognostic Parameter and Its Targeted Therapies in Ewing Sarcoma

Ewing sarcoma (ES) is a rare, highly aggressive, bone, or soft tissue-associated tumor. Although this sarcoma often responds well to initial chemotherapy, 40% of the patients develop a lethal recurrence of the disease, with death recorded in 75-80% of patients with metastatic ES within 5 years, despite receiving high-dose chemotherapy. ES is genetically well-characterized, as indicated by the EWS-FLI1 fusion protein encoded as a result of chromosomal translocation in 80-90% of patients with ES, as well as in ES-related cancer cell lines. Recently, tyrosine kinases have been identified in the pathogenesis of ES. These tyrosine kinases, acting as oncoproteins, are associated with the clinical pathogenesis, metastasis, acquisition of self-renewal traits, and chemoresistance of ES, through the activation of various intracellular signaling pathways. This review describes the recent progress related to cellular and molecular functional roles of tyrosine kinases in the progression of ES.

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.

Treatment Outcomes After Proton Therapy for Ewing Sarcoma of the Pelvis

PURPOSE

Ewing sarcoma of the pelvis is associated with inferior local control compared with those arising from other primary sites. Despite its increased use, outcome data for treatment with proton therapy remain limited. We report 3-year disease control and toxicity in pediatric patients treated with proton therapy.

METHODS AND MATERIALS

Thirty-five patients aged ≤21 years (median, 14 years) with nonmetastatic pelvic Ewing sarcoma received proton therapy and chemotherapy between 2010 and 2018. Overall survival and tumor control rates were calculated using the Kaplan-Meier method. A log-rank test assessed significance between strata of prognostic factors. Significant toxicity was reported per the Common Terminology Criteria for Adverse Events, version 4.0.

RESULTS

Most patients received definitive radiation (n = 26; median dose 55.8 Gy relative biological effectiveness [RBE]; range, 54.0-64.8), 7 received preoperative radiation (50.4 Gy RBE), and 2 received postoperative radiation (45 Gy RBE and 54 Gy RBE). The median primary tumor size was 10.5 cm. With a median follow-up of 3 years (range, 0.3-9.0 years), the 3-year overall survival, progression-free survival, and local control rates were 83% (95% confidence interval [CI], 65%-93%), 64% (95% CI, 45%-79%), and 92% (95% CI, 74%-98%), respectively. There was no association between local control, progression-free survival, or overall survival and tumor size, patient age, radiation dose, or definitive versus pre-/postoperative radiation therapy. Median time to progression was 1 year (range, 0.1-1.9 years). All patients with large tumors (≥8 cm) who underwent definitive proton therapy with a higher dose (≥59.4 Gy RBE) remained free from tumor recurrence (n = 5). Five patients experienced grade ≥2 subacute/late toxicity, all of whom were treated with combined surgery and radiation.

CONCLUSIONS

Definitive proton therapy offers local control comparable to photon therapy in pediatric patients with pelvic Ewing sarcoma. These data lend preliminary support to radiation dose escalation without significant toxicity, which may contribute to the favorable outcomes. Combined surgery and radiation therapy, particularly preoperative radiation, is associated with postoperative complications, but not survival, compared with radiation alone.

The impact of local control timing in Ewing sarcoma

AIM

To assess the impact of delay in local control on survival outcomes of Ewing sarcoma (ES) patients.

BACKGROUND

The cornerstone of therapy of localized ES includes chemotherapy and local control with surgery or radiotherapy. We sought to assess the impact of delay (>15 weeks) in timing of local control on survival outcomes of ES patients.

METHODS

Data of consecutive patients with primary non-metastatic ES of the extremities, treated at a single institution were collected. The impact of delay of timing for local control, demographics, and disease characteristics on overall survival (OS) was analyzed.

RESULTS

A total of 43 patients with ES of the extremity were included. All patients received neoadjuvant chemotherapy. Local control was by surgery in 36 patients and definitive radiation in 7. A total of 16 patients had delay in local control. At a median follow of up of 48 months, patients with delay in local control had significantly inferior OS compared to those with optimal local control timing (5-year OS 56% vs. 80%, respectively, p = 0.044). Other factors that predicted inferior OS included definitive radiation as opposed to definitive surgery (5-year OS 25% vs. 79%, respectively, p = 0.041) and tumor necrosis <90% as opposed to ≥90% (5-year OS 55% vs. 90%, respectively, p = 0.01).

CONCLUSION

Delay in definitive therapy, local control with radiation as opposed to surgery and poor post-chemotherapy tumor necrosis predict inferior OS in ES. Adopting strategies to minimize delay in local control could improve survival outcomes.

Treatment of pelvic Ewing's sarcoma: Pros and cons of chemotherapy plus definitive radiotherapy versus surgery

OBJECTIVE

The aim of this study was to compare the results of chemotherapy or combined chemotherapy-radiation therapy with surgical intervention following neodjuvant therapy in pelvic Ewing's sarcoma patients.

METHODS

The study population consisted of 39 patients with pelvic Ewing's sarcoma treated in our clinic between 1994 and 2014. Of these patients, 28 patients (11 boys and 17 girls; mean age: 19.57±6.8 years) were treated with chemotherapy and radiation therapy and the remaining 11 patients (9 boys and 2 girls; mean age: 18.64±8.1 years) patients underwent surgical intervention after neoadjuvant chemotherapy or chemotherapy plus radiation therapy. Internal hemipelvectomy was performed in 10 patients, and external hemipelvectomy was performed in one patient. Survival rates were compared between the surgical and non-surgical treatment groups. Predictive factors, such as treatment protocol (surgery, neoadjuvant chemotherapy, definitive radiotherapy), mass localisation, mass size, presence of metastasis at the time of diagnosis, and presence of late metastases were compared between the groups. The effects of each variable on survival were also examined.

RESULTS

The overall 3- and 5-year survival rates of the 28 non-surgical patients were 41.4% and 26.1%, respectively, while those of the surgical patients were 53% and 35.4%, respectively (p=0.777). Large mass size, presence of metastasis at the time of diagnosis, and presence of late metastases were significantly associated with lower survival rates.

CONCLUSION

The survival rates of the patients who underwent surgery were higher than those of non-surgical patients, although the difference was not statistically significant. Definitive radiation and chemotherapy would be preferable in selected cases, such as patients with sacral localisation, without surgical intervention.

LEVEL OF EVIDENCE

Level III, Therapeutic Study.

Insurance impacts survival for children, adolescents, and young adults with bone and soft tissue sarcomas

Background

While racial/ethnic survival disparities have been described in pediatric oncology, the impact of income has not been extensively explored. We analyzed how public insurance influences 5‐year overall survival (OS) in young patients with sarcomas.

Methods

The University of California San Francisco Cancer Registry was used to identify patients aged 0‐39 diagnosed with bone or soft tissue sarcomas between 2000 and 2015. Low‐income patients were defined as those with no insurance or Medicaid, a means‐tested form of public insurance. Survival curves were computed using the Kaplan‐Meier method and compared using log‐rank tests and Cox models. Causal mediation was used to assess whether the association between public insurance and mortality is mediated by metastatic disease.

Results

Of 1106 patients, 39% patients were classified as low‐income. Low‐income patients were more likely to be racial/ethnic minorities and to present with metastatic disease (OR 1.96, 95% CI 1.35‐2.86). Low‐income patients had significantly worse OS (61% vs 71%). Age at diagnosis and extent of disease at diagnosis were also independent predictors of OS. When stratified by extent of disease, low‐income patients consistently had significantly worse OS (localized: 78% vs 84%, regional: 64% vs 73%, metastatic: 23% vs 30%, respectively). Mediation analysis indicated that metastatic disease at diagnosis mediated 15% of the effect of public insurance on OS.

Conclusions

Low‐income patients with bone and soft tissue sarcomas had decreased OS regardless of disease stage at presentation. The mechanism by which insurance status impacts survival requires additional investigation, but may be through reduced access to care.

The adrenergic receptor antagonists propranolol and carvedilol decrease bone sarcoma cell viability and sustained carvedilol reduces clonogenic survival and increases radiosensitivity in canine osteosarcoma cells

Adrenergic receptor (AR) expression has been demonstrated at several sites of primary and metastatic tumour growth and may influence proliferation, survival, metastasis and angiogenesis. AR antagonists like propranolol and carvedilol inhibit proliferation, induce apoptosis and synergize with chemotherapy agents in some cancers. Radiation resistance is mediated in many cells by upregulation of pro-survival pathways, which may be influenced by ARs. Studies evaluating AR antagonists combined with radiation are limited. The purpose of this study was to determine the effect of propranolol and carvedilol on viability and radiosensitivity in sarcoma cell lines. The hypothesis was that propranolol and carvedilol would increase radiosensitivity in four primary bone sarcoma cell lines. Single agent propranolol or carvedilol inhibited cell viability in all cell lines in a concentration-dependent manner. The mean inhibitory concentrations (IC₅₀ ) for carvedilol were approximately 4-fold lower than propranolol and may be clinically relevant in vivo. Immunoblot analysis confirmed AR expression in both human and canine sarcoma cell lines; however, there was no correlation between baseline AR protein expression and radiosensitivity. Short duration treatment with carvedilol and propranolol did not significantly affect clonogenic survival. Prolonged exposure to propranolol and carvedilol significantly decreased the surviving fraction of canine osteosarcoma cells after 3Gy radiation. Based on our results and possible in vivo activity in dogs, further studies investigating the effects of carvedilol on sarcoma are warranted.

Clinical characteristics and treatment-associated survival of head and neck Ewing sarcoma

OBJECTIVES

Ewing sarcoma of the head and neck (ESHN) is a rare malignancy for which limited data exists. Herein we examine anatomic distribution of ESHN, demographic characteristics, and multi-modal therapy as potential determinants in the overall survival (OS) of patients with ESHN.

METHODS

A retrospective study of the National Cancer Database (NCDB) from 2004-2016 was performed. A multivariate Cox regression and univariate Kaplan-Meier survival analyses were conducted.

RESULTS

We identified 284 patients with ESHN eligible for demographic analysis and 223 for survival analysis. Approximately half (50.3%) of patients with ESHN were under the age of 18. Pediatric patients (<18) were less likely to present with distant metastases (≤8.0% vs. 9.5-19.0%, P = .006) and more likely to present with osseous disease (90.2% vs. 75.2%, P = .001) than adults. Adult age (HR: 2.727, 95% CI, 1.381-5.384, P = .004) and distant metastatic disease at the time of presentation (HR: 8.161, 95% CI, 2.922-22.790, P < .001) were independently associated with worse OS. The addition of local therapy (either surgery, radiotherapy, or both) to chemotherapy was not associated with improved survival when compared to treatment with chemotherapy alone.

CONCLUSION

Predictors of OS in patients with ESHN included age < 18 years and non-metastatic disease at the time of diagnosis. Tumor site of origin (osseous vs. extraosseous primary) or the addition of local therapy to chemotherapy had no impact on OS. Our analysis suggests that chemotherapy serves as the primary modality in treating ESHN, while further study of this rare malignancy is required to discern the utility of combined systemic and local therapy. Laryngoscope, 130:2385-2392, 2020.

Pediatric Cancer

In pediatric brain tumors, the intensification of chemotherapy has allowed for a reduction in radiotherapy (RT) volume to an involved field approach, particularly in patients with medulloblastoma. For patients with low-grade gliomas, the trend has remained to delay RT with chemotherapy; however, when RT is used, typically smaller clinical target volume margins are used. For patients with extracranial tumors, intensive chemotherapy to address systemic disease with local control is considered standard. Proton beam therapy shows significant promise in addressing both short-term and long-term toxicities in both central nervous system (CNS) and non-CNS pediatric tumors.