Recurrence of Ewing sarcoma: Is detection by imaging follow-up protocol associated with survival advantage?

Rare presentation of Ewing's sarcoma underscores the diagnostic challenges in atypical cases

A female patient in her late teens presented with an initially episodic right-sided chest pain that gradually became persistent and associated with a high-grade fever, starting 15 days earlier but worsening over a week. Physical examination revealed tenderness on the right side of the chest and reduced air entry in the right middle and lower lung fields. Initial imaging demonstrated a right-sided pleural effusion with a chest wall mass lesion. A chronic infection like tuberculosis (TB) was suspected. However, an ultrasound-guided thoracentesis confirmed an exudative pleural effusion with low adenosine deaminase. Further, fine needle aspiration cytology of the mass revealed atypical small round cells with scanty cytoplasm and an immunohistochemistry profile consistent with Ewing's sarcoma. This case highlights the diagnostic challenges accompanying an unusual presentation of Ewing's sarcoma in the TB endemic region, which typically affects long bones but, in this instance, is manifested with pleural involvement and symptoms.

Clinical practice guidelines for the treatment of Ewing sarcoma (Spanish Sarcoma Research Group-GEIS)

Ewing sarcoma is a small round-cell sarcoma characterized by gene fusion involving EWSR1 (or another TET family protein like FUS) and an ETS family transcription factor. The estimated incidence of this rare bone tumor, which occurs most frequently in adolescents and young adults, is 0.3 per 100,000/year. Although only 25% of patients with Ewing sarcoma are diagnosed with metastatic disease, historical series show that this is a systemic disease. Patient management requires multimodal therapies-including intensive chemotherapy-in addition to local treatments (surgery and/or radiotherapy). In the recurrent/refractory disease setting, different approaches involving systemic treatments and local therapies are also recommended as well as patient inclusion in clinical trials whenever possible. Because of the complexity of Ewing sarcoma diagnosis and treatment, it should be carried out in specialized centers and treatment plans should be designed upfront by a multidisciplinary tumor board. These guidelines provide recommendations for diagnosis, staging, and multimodal treatment of Ewing sarcoma.

The significance of surveillance imaging in children with Ewing sarcoma and osteosarcoma

Primary bone tumors in children and adolescents, while rare, pose significant challenges in diagnosis and management. Children treated for Ewing sarcoma and osteosarcoma are offered a 5-year follow-up program after end of treatment, including radiological surveillance of primary location of tumor and the lungs. There is no consensus regarding how often and how the children should be followed with radiological imaging. This retrospective descriptive study of 69 patients (34 with Ewing sarcoma and 35 with osteosarcoma) investigated the consequences of abnormal findings in 1279 follow-up images. Nine relapses were detected, 4 in the Ewing group (3 local and 1 pulmonary) and 5 in the osteosarcoma group (1 local and 4 pulmonary). Of these, only two patients exhibited symptomatic relapses, with the remainder identified through imaging. The positive predictive value for relapse detection was 0.44 in the Ewing group, and 0.5 in the osteosarcoma group. In the Ewing sarcoma patient image follow-up program, the probability of anomaly detection was 12% (95% CI, 10-15). For osteosarcoma patients, the likelihood was 6% (95% CI, 4-8). Our data indicates that abnormal findings on follow-up images rarely represents relapse of tumor. As the surveillance protocol differs between the patient groups, wherein Ewing sarcoma patients primarily are monitored through MRI while osteosarcoma patients are predominantly tracked via X-rays, there is an increased occurrence of incidental findings in the first group. However, it is imperative to interpret imaging data in conjunction with clinical information, avoiding isolated reliance on imaging results when making treatment decisions.

Postoperative Relapse Prediction in Patients With Ewing Sarcoma Using Computed Tomography-Based Radiomics Models Covering Tumor Per Se and Peritumoral Signatures

OBJECTIVE

We aimed to develop and validate a computed tomography (CT)-based radiomics model for early relapse prediction in patients with Ewing sarcoma (ES).

METHODS

We recruited 104 patients in this study. Tumor areas and areas with a tumor expansion of 3 mm were used as regions of interest for radiomics analysis. Six different models were constructed: Pre-CT, CT enhancement (CTE), Pre-CT +3 mm , CTE +3 mm , Pre-CT and CTE combined (ComB), and Pre-CT +3 mm and CTE +3 mm combined (ComB +3 mm ). All 3 classifiers used a grid search with 5-fold cross-validation to identify their optimal parameters, followed by repeat 5-fold cross-validation to evaluate the model performance based on these parameters. The average performance of the 5-fold cross-validation and the best one-fold performance of each model were evaluated. The AUC (area under the receiver operating characteristic curve) and accuracy were calculated to evaluate the models.

RESULTS

The 6 radiomics models performed well in predicting relapse in patients with ES using the 3 classifiers; the ComB and ComB +3 mm models performed better than the other models (AUC -best : 0.820-0.922/0.823-0.833 and 0.799-0.873/0.759-0.880 in the training and validation cohorts, respectively). Although the Pre-CT +3 mm , CTE +3 mm, and ComB +3 mm models covering tumor per se and peritumoral CT features preoperatively forecasted ES relapse, the model was not significantly improved.

CONCLUSIONS

The radiomics model performed well for early recurrence prediction in patients with ES, and the ComB and ComB +3 mm models may be superior to the other models.

Imaging of pediatric bone tumors: A COG Diagnostic Imaging Committee/SPR Oncology Committee White Paper

Malignant primary bone tumors are uncommon in the pediatric population, accounting for 3%-5% of all pediatric malignancies. Osteosarcoma and Ewing sarcoma comprise 90% of malignant primary bone tumors in children and adolescents. This paper provides consensus-based recommendations for imaging in children with osteosarcoma and Ewing sarcoma at diagnosis, during therapy, and after therapy.

Relapsing pediatric non-rhabdomyosarcoma soft tissue sarcomas: The impact of routine imaging surveillance on early detection and post-relapse survival

PURPOSE

The chances of patients with relapsing pediatric non-rhabdomyosarcoma soft tissue sarcomas (NRSTS) being cured are limited. This retrospective single-institutional study examines the potential role of routine surveillance imaging for detecting recurrent tumor, and its impact on post-relapse survival.

METHODS

The analysis concerned 86 patients < 21 years old with relapsing NRSTS treated from 1985 to 2020. Clinical findings, treatment modalities and survival were analyzed, comparing patients whose relapse was first suspected from symptoms (symptomatic group) with those whose relapse was detected by radiological surveillance (imaging group).

RESULTS

Tumor relapses were identified from clinical symptoms in 49 cases and on routine imaging in 37. Time to relapse was similar in the two groups. Routine imaging detected 6/32 local relapses and 31/48 distant relapses (and 79% of the cases of lung metastases). Overall survival (OS) at 5 years was 34.3% for the symptomatic group, and 24.0% for the imaging group (p-value 0.270). In patients with lung metastases at relapse, the 5-year OS was statistically better for the imaging group, that is, 25.8% versus 0% for the symptomatic group (p-value 0.044).

CONCLUSION

This is the first study to explore the role of surveillance imaging in pediatric NRSTS. Judging from our findings, the value of routine scanning of primary sites seems limited, while radiological surveillance may help to detect lung metastases, improving survival for this patient category. The potentially negative effects of periodic radiological exams should be considered in deciding the optimal follow-up for patients off therapy.

What Are the Results of Limb Salvage Surgery for Primary Malignant Bone Tumor in the Forearm?

Background and Objectives

After diagnosing a primary bone tumor involving the forearm, various excision strategies and reconstruction methods must be considered. This study explored the oncological and functional outcomes of limb salvage surgery for primary malignant bone tumors in the forearm.

Methods

Patients with primary forearm bone tumors (n = 369) were retrospectively analyzed between 2000 and 2017. There were 266 patients with radial tumors, and 46 (17.3%) were malignant, whereas 103 patients had ulnar lesions and 22 (21.4%) were malignant tumors. The oncological results, prognostic factors, and functional results after limb salvage surgery of forearm malignancies were analyzed.

Results

The follow-up averaged 72.1 (7–192, median 62.5) months. Fifty-six patients who received limb salvage surgery were included in the final evaluation. Radius resection was performed in 38 patients, and distal radius (25 patients) was most frequent. Ulnar resection was performed in 18 patients, and the proximal ulna (13 patients) was most frequent. The surgical margins obtained were intralesional in 3 patients, marginal in 8 patients and wide in 45 patients. Local recurrence occurred in 11 patients (19.6%), and distant metastasis occurred in 14 patients (25%). The 5-year recurrence-free survival rate was 79.8%. Unplanned excision, ulnar involvement, proximal forearm location and inadequate surgical margins were associated with recurrence. The overall 5-year and 10-year survival rates were 83.5 and 71.7%, respectively. Distant metastasis was a poor prognostic factor for the survival rate. Forty-two patients were evaluated by MSTS score with an average of 27.9 ± 1.5.

Conclusions

The incidence of radial malignant tumors is higher than that of ulnar lesions. The distal radius and the proximal ulna are the most frequently involved sites. Unplanned excisions, ulnar tumors, proximal forearm tumors, and inadequate surgical margin are the risk factors for local recurrence. Distant metastasis is an independent poor prognostic factor of death. The oncology control and functional results of limb salvage surgery were satisfactory.

Trends in Tumor Site-Specific Survival of Bone Sarcomas from 1980 to 2018: A Surveillance, Epidemiology and End Results-Based Study

OBJECTIVES

As diagnosis and treatment guidelines for bone sarcomas continue updating, it is important to examine whether, when, and which kinds of patients have had a survival improvement over the last four decades.

METHODS

This cohort study included 9178 patients with primary bone and joint sarcomas from 1 January 1980 to 31 December 2018 using data from Surveillance, Epidemiology and End Results (SEER)-9 Registries. The follow-up period was extended to November 2020. Patients were divided by decade into four time periods: 1980-1989, 1990-1999, 2000-2009, and 2010-2018. The primary endpoint was bone sarcomas-specific mortality (CSM). The 5-year bone sarcomas-specific survival (CSS) rate was determined stratified by demographic, neoplastic, temporal, economic, and geographic categories. The associations between time periods and CSM were examined using a multivariable Cox regression model, with reported hazard ratio (HR) and 95% confidence interval (CI).

RESULTS

The 5-year CSS rate for bone sarcomas was 58.7%, 69.9%, 71.0%, and 69.2%, in the 1980s, 1990s, 2000s, and 2010s, respectively. Older age, male gender, tumor sites at pelvic bones, sacrum, coccyx and associated joints, as well as vertebral column, osteosarcoma and Ewing tumor, and residence in non-metropolitan areas were independently associated with higher CSM risk. After adjusting for the covariates above, patients in the 1990s (HR = 0.74, 95% CI = 0.68-0.82), 2000s (HR = 0.71, 95% CI = 0.65-0.78), and 2010s (HR = 0.68, 95% CI = 0.62-0.76) had significantly lower CSM risks than patients in the 1980s. However, patients in the 2000s and 2010s did not have lower CSM risks than those in the 1990s (both p > 0.05).

CONCLUSIONS

Although bone sarcomas survival has significantly improved since 1990, it almost halted over the next three decades. Bone sarcomas survival should improve over time, similar to common cancers. New diagnostic and therapeutic strategies such as emerging immune and targeted agents are warranted to overcome this survival stalemate.

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.

Pain in survivors of Ewing sarcoma: Prevalence, associated factors and prediction of recurrence

BACKGROUND

While the prognosis of patients with Ewing sarcoma (EwS) is improving, little is known about the frequency of pain and its risk factors in survivors of EwS. This study aims to analyse the prevalence and risk factors of pain and its predictive value for recurrence.

PATIENTS AND METHODS

In patients with remission after treatment of EwS, frequency and characteristics of pain within the first 5 years of follow up were assessed retrospectively.

RESULTS

Of 80 patients, 37 (46%) presented with at least one episode of pain. Chronic pain (>3 months) was observed in 10 patients (13%). Experience of at least one episode of pain was associated with prior combined local treatment (surgery and radiation compared to surgery alone; odds ratio [OR] 5.83, 95% confidence interval [CI] 1.43-34.9, P = .007). A total of 59 episodes of pain were observed, including 47 acute and 12 chronic episodes. Lower limb pain accounted for 46% (27/59) of all episodes of pain, and was associated with primary tumour of the pelvis or lower extremity (OR 4.29, 95% CI 1.18-18.21, P = .025), which represented 64% (51/80) of all EwS. The positive predictive value of pain for recurrence was only 12%.

CONCLUSION

Pain is a common problem in survivors of EwS, which mostly affects the lower extremity, and should be regularly assessed. Interventions to reduce pain may be particularly important in patients with combined local treatment with surgery and radiation, who seem to be at considerably increased risk for pain. Patients presenting with pain should be examined for recurrence.

A systematic review of evidence for and against routine surveillance imaging after completing treatment for childhood extracranial solid tumors

BACKGROUND

Regular off-treatment imaging is often used to assess for recurrence of disease after childhood cancer treatment. It is unclear if this increases survival, or what burden surveillance places on patients, families, or health-care services. This systematic review examines the impact of routine surveillance imaging after treatment of pediatric extracranial solid tumors.

METHODS

Collaborative patient and public involvement informed the design and interpretation of this work. Thirteen electronic databases, conference proceedings, and trial registries were searched alongside reference list checking and forward citation searching from 1990 onwards. Studies were screened and data were extracted by two researchers. Risk of bias was assessed using a modified ROBINS-I tool. Relevant outcomes were overall survival, psychological distress indicators, number of imaging tests, cost-effectiveness, and qualitative data regarding experiences of surveillance programs. PROSPERO (CRD42018103764).

RESULTS

Of 17 727 records identified, 55 studies of 10 207 patients were included. All studies used observational methods. Risk of bias for all except one study was moderate, serious, or critical. Data were too few to conduct meta-analysis; however, narrative synthesis was performed. Surveillance strategies varied, and poorly reported, involving many scans and substantial radiation exposure (eg, neuroblastoma, median 133.5 mSv). For most diseases, surveillance imaging was not associated with increased overall survival, with the probable exception of Wilms tumor. No qualitative or psychological distress data were identified.

CONCLUSIONS

At present, there is insufficient evidence to evaluate the effects of routine surveillance imaging on survival in most pediatric extracranial solid tumors. More high-quality data are required, preferably through randomized controlled trials with well-conducted qualitative elements.

Management of Refractory Pediatric Sarcoma: Current Challenges and Future Prospects

Paediatric sarcomas are a heterogeneous group of disorders constituting bone sarcoma and various soft tissue sarcomas. Almost one-third of these presents with metastasis at baseline and another one-third recur after initial curative treatment. There is a huge unmet need in this cohort in terms of curative options and/or prolongation of survival. In this review, we have discussed the current treatment options, challenges and future strategies of managing relapsed/refractory paediatric sarcomas. Upfront risk-adapted treatment with multidisciplinary management remains the main strategy to prevent future recurrence or relapse of the disease. In the case of limited local and/or systemic relapse or late relapse, initial multimodality management can be administered. In treatment-refractory cases or where cure is not feasible, the treatment options are limited to novel therapeutics, immunotherapeutic approach, targeted therapies, and metronomic therapies. A better understanding of disease biology, mechanism of treatment refractoriness, identifications of driver mutation, the discovery of novel targeted therapies, cellular vaccine and adapted therapies should be explored in relapsed/refractory cases. Close national and international collaboration for translation research is needed to fulfil the unmet need.

Post-treatment FDG PET/CT predicts progression-free survival in young patients with small round blue cell tumors: Ewing sarcoma and PNET

PURPOSE

To determine if post-treatment F-18 FDG PET/CT results (overall positive findings, specific localizations) are independent predictors of disease progression in young patients with Ewing sarcoma and Primitive neuroectodermal tumor.

METHOD

A consecutive sample of 48 patients (age 14 ± 5 years, 32 male) was referred to F-18 FDG PET/CT for the suspected progression of Ewing sarcoma (39 patients) and Primitive neuroectodermal tumor (PNET) (9 patients) and followed-up clinically for 4.3 ± 2.3 years after F-18 FDG PET/CT (range 1-8 years). The diagnostic value of F-18 FDG PET/CT was determined in comparison to the biopsy. Kaplan-Meier analysis was used to compare progression-free survival between the groups with positive and negative F-18 FDG PET/CT findings. Variables included in the Cox regression for predicting the progression-free survival were sex, age, F-18 FDG PET/CT findings, MDCT findings, and MR ratio.

RESULTS

F-18 FDG PET/CT findings were positive in 32 (67 %) patients (sensitivity 93.7 %, specificity 87.5 %, accuracy 91.7 %) with an average SUVmax of 5.8 ± 3.2 (95 % CI 4.8-7.1). The progression-free survival was significantly lower (p = 0.001) in patients with positive F-18 FDG PET/CT findings (median 28 months) and when recurrence was located in bones, soft tissues, and muscles (p = 0.02, median 21 months). The significant predictors of the disease progression were the overall positive F-18 FDG PET/CT findings (HR 8.36, p = 0.004) and, specifically, the local recurrence in the bone with infiltration of soft tissue/muscles (HR 4.08, p = 0.003).

CONCLUSION

Post-treatment F-18 FDG PET/CT findings are useful for predicting the progression of Ewing sarcoma and PNET and should be included in the clinical monitoring of these patients.

Routine Surveillance Imaging Is Associated with Improved Postrelapse Survival in Patients with Ewing Sarcoma

Purpose: Children with Ewing sarcoma (ES) routinely undergo surveillance imaging after completion of therapy; however, the medical benefit of this imaging remains unclear. We aimed to determine whether there is a difference in survival between patients whose relapse was detected based on development of new symptoms or by routine imaging. Methods: We retrospectively reviewed all patients consecutively diagnosed with ES at Children's Healthcare of Atlanta from 2000 to 2011. Patient characteristics and outcomes were compared based on whether their relapse was diagnosed based on symptoms or by routine surveillance imaging alone. Results: Thirty-three percent (28/85) of patients relapsed. Median age at time of relapse was 15.5 years (interquartile range: 12.5-18.0). Among the relapsed patients, 57% (16/28) were symptomatic and 43% (12/28) were asymptomatic, having relapse detected on surveillance imaging alone. The most common presenting symptom was bone pain occurring in 69% (11/16) of patients. The 5-year postrelapse overall survival for patients with symptomatic relapse was 0% (95% confidence interval [CI]: not estimated) compared with 15% (95% CI: 1-48) for patients with an asymptomatic relapse (p < 0.01). After adjusting for extent of disease and time to relapse, having a symptomatic relapse was still strongly associated with a worse outcome (hazard ratio: 9.68; 95% CI: 3.09-30.34). Conclusion: Patients with ES whose relapse is detected on imaging before the development of symptoms have significantly better outcomes, suggesting a potentially beneficial role of routine surveillance imaging in this population of patients. Further prospective analyses are needed to confirm these findings, and determine the optimal evidence-based imaging modality and schedule.

Is surveillance imaging in pediatric patients treated for localized rhabdomyosarcoma useful? The European experience

Background

After the completion of therapy, patients with localized rhabdomyosarcoma (RMS) are subjected to intensive radiological tumor surveillance. However, the clinical benefit of this surveillance is unclear. This study retrospectively analyzed the value of off‐therapy surveillance by comparing the survival of patients in whom relapse was detected by routine imaging (the imaging group) and patients in whom relapse was first suspected by symptoms (the symptom group).

Methods

This study included patients with relapsed RMS after the completion of therapy for localized RMS who were treated in large pediatric oncology hospitals in France, the United Kingdom, Italy, and the Netherlands and who were enrolled in the International Society of Paediatric Oncology Malignant Mesenchymal Tumor 95 (1995‐2004) study, the Italian Paediatric Soft Tissue Sarcoma Committee Rhabdomyosarcoma 96 (1996‐2004) study, or the European Paediatric Soft Tissue Sarcoma Study Group Rhabdomyosarcoma 2005 (2005‐2013) study. The survival times after relapse were compared with a log‐rank test between patients in the imaging group and patients in the symptom group.

Results

In total, 199 patients with relapsed RMS were included: 78 patients (39.2%) in the imaging group and 121 patients (60.8%) in the symptom group. The median follow‐up time after relapse was 7.4 years (interquartile range, 3.9‐11.5 years) for survivors (n = 86); the 3‐year postrelapse survival rate was 50% (95% confidence interval [CI], 38%‐61%) for the imaging group and 46% (95% CI, 37%‐55%) for the symptom group (P = .7).

Conclusions

Although systematic routine imaging is the standard of care after RMS therapy, the majority of relapses were detected as a result of clinical symptoms. This study found no survival advantage for patients whose relapse was detected before the emergence of clinical symptoms. These results show that the value of off‐therapy surveillance is controversial, particularly because repeated imaging may also entail potential harm.

This study assesses the clinical value of radiological surveillance imaging in pediatric patients with rhabdomyosarcoma, which is routinely performed after the completion of therapy. In the majority of patients, relapse is detected because of symptoms, and there is no evidence that early detection by imaging results in improved survival.

[The importance of radiology in bone sarcoma diagnostics : Initial and advanced diagnostics]

BACKGROUND

Reliable diagnostic assessment of malignant bone lesions remains a challenge in all the medical disciplines involved. The high incidence of benign (mainly pediatric) bone lesions needs to be distinguished from the rare malignant counterparts. If clinical presentation and patient history are unable to exclude a malignant tumour, adequate imaging of the affected region is necessary.

OBJECTIVES

This article focuses on giving implementable advice in dealing with problems and questions arising in the diagnostic process of treating patients with suspected or confirmed bone sarcoma. Also, follow-up recommendations from a radiological point of view are presented.

METHODS

Review and discussion of relevant literature against personal experiences in the medical imaging of patients with bone sarcomas.

RESULTS

Interpretation of projection radiographic images usually succeeds in assessing a bone tumour's dignity by evaluating periosteal reaction, the formation of a tumour matrix and consideration of the Lodwick classification. A current adaptation of the classic Lodwick classification incorporates diagnostic possibilities of more recent imaging techniques (magnetic resonance imaging (MRI), positron emission tomography (PET)) and is presented in this article. Plain radiographs are superseded by MRI as the primary imaging performed when depicting bone lesions with increasing frequency. The role of MRI in terms of primary diagnostics, staging, planning of biopsy tracts and tumour resections, evaluation of treatment response and follow-up are discussed. All diagnostic imaging techniques, including whole-body imaging methods, relevant in the diagnosis and therapy of bone sarcomas are presented in the sequence in which they appear during treatment.

CONCLUSIONS

Radiological imaging and expertise are important pillars in diagnosis and treatment of bone sarcomas. A variety of complementing imaging techniques provide a treatment-relevant basis significant for all medical disciplines involved.

European Society of Paediatric Radiology 2019 strategic research agenda: improving imaging for tomorrow's children

The European Society of Paediatric Radiology (ESPR) research committee was established to initiate, drive forward and foster excellence in paediatric imaging, paediatric image-guided intervention and radiation protection research, by facilitating more evidence-based standards, protocols and multi-institutional collaborations. The ESPR Strategic Research Agenda outlines our current research approach, highlighting several areas of paediatric imaging where the society can help guide current and future research, and emphasizing those areas where early research ("seed") funding may need to be allocated by this and other societies as precursors to larger grant applications. The key aims are to evaluate normal variation in order to be able to confidently diagnose disease states, develop robust image-based classification systems to aid diagnosis and treatment monitoring, and help develop evidence-based clinical guidelines using current literature and experience to identify knowledge gaps. For this reason, the development of evidence-based imaging pipelines, broken down step-by-step to include diagnosis, classification and clinical effectiveness, should be the end goal for each disease entity for each affected child. Here, we outline the 2019 ESPR Strategic Research Agenda along three points in the clinical imaging pipeline: clinical referral, disease diagnosis and evolution, and clinical therapeutic evaluation and effectiveness. Through multicentre trials, using existing high-level experience and expertise, and nurturing the next generation of researchers, we will be able to achieve these aims.

Management of recurrent Ewing sarcoma: challenges and approaches

Although many patients with newly diagnosed Ewing sarcoma can become long-term survivors, relapse remains an important clinical problem for which there is no standard approach. Several prognostic factors have been identified, and these may help guide patient counseling and therapy decisions. A variety of chemotherapy regimens have produced responses in patients with recurrent Ewing sarcoma, but no comparative studies have been completed to show superiority of any one particular approach. In addition, the optimum length of therapy for salvage regimens and use of local control measures remains unknown. The likelihood of cure remains low and the gaps in our knowledge are great, and so enrollment on clinical trials should be strongly encouraged for these patients when feasible. Because Ewing sarcoma is relatively rare, some pediatric and adult oncologists may be less familiar with the management of relapsed patients. In this review, we address common questions facing the clinician and patient, and provide an update on new strategies for therapy.

Getting control during follow-up visits: the views and experiences of parents on tumor surveillance after their children have completed therapy for rhabdomyosarcoma or Ewing sarcoma

Purpose

Patients treated for rhabdomyosarcoma (RMS) or Ewing sarcoma (ES) are subject to extensive follow-up after completion of therapy. The aim of this follow-up is to monitor treatment side effects and to detect relapse in an early phase to improve prognosis after relapse. Little is known about parental emotional experiences during this period. We assessed the views and experiences of parents of children treated for RMS or ES on the follow-up examinations after completion of therapy.

Methods

We conducted two focus group meetings and four semi-structured telephone interviews with parents of children treated for RMS or ES in Dutch pediatric oncology centers. Parents of children 0–5 years after end-of-therapy were invited via letters (response rate 31%) and via social media channels of “Dutch Childhood Association for Children and Parents” (VOKK). An inductive thematic approach was used to analyze the data.

Results

In total, 12 parents (fathers, n = 3; mothers, n = 9) of 12 patients treated for RMS (n = 6) or ES (n = 6) participated. Median age at diagnosis for their children was 7.9 years and median time after end-of-treatment was 37 months. Four major themes were identified: content of follow-up, distress and anxiety, search for reassurance and hope, and interaction with others. Parents of children treated for RMS or ES report experiencing significant distress after completion of treatment. They report that their distress was decreased by adequate communication about content, timing, and reasoning behind follow-up.

Conclusion

Physicians should pay attention to the needs of individual parents to reduce distress in the period after completion of therapy.

Ewing sarcoma

Ewing sarcoma is the second most frequent bone tumour of childhood and adolescence that can also arise in soft tissue. Ewing sarcoma is a highly aggressive cancer, with a survival of 70-80% for patients with standard-risk and localized disease and ~30% for those with metastatic disease. Treatment comprises local surgery, radiotherapy and polychemotherapy, which are associated with acute and chronic adverse effects that may compromise quality of life in survivors. Histologically, Ewing sarcomas are composed of small round cells expressing high levels of CD99. Genetically, they are characterized by balanced chromosomal translocations in which a member of the FET gene family is fused with an ETS transcription factor, with the most common fusion being EWSR1-FLI1 (85% of cases). Ewing sarcoma breakpoint region 1 protein (EWSR1)-Friend leukaemia integration 1 transcription factor (FLI1) is a tumour-specific chimeric transcription factor (EWSR1-FLI1) with neomorphic effects that massively rewires the transcriptome. Additionally, EWSR1-FLI1 reprogrammes the epigenome by inducing de novo enhancers at GGAA microsatellites and by altering the state of gene regulatory elements, creating a unique epigenetic signature. Additional mutations at diagnosis are rare and mainly involve STAG2, TP53 and CDKN2A deletions. Emerging studies on the molecular mechanisms of Ewing sarcoma hold promise for improvements in early detection, disease monitoring, lower treatment-related toxicity, overall survival and quality of life.