Local therapy in localized Ewing tumors: results of 1058 patients treated in the CESS 81, CESS 86, and EICESS 92 trials

Limited Margin Radiation Therapy for Children and Young Adults With Ewing Sarcoma Achieves High Rates of Local Tumor Control

PURPOSE

To determine the rate of local failure using focal conformal, limited margin radiation therapy (RT) and dose escalation for tumors ≥8 cm (greatest dimension at diagnosis) in children and young adults with Ewing sarcoma (EWS).

METHODS AND MATERIALS

Eligible patients with EWS were treated on a phase 2 institutional trial of focal conformal, limited margin RT using conformal or intensity modulated techniques. The treatment volume incorporated a 1-cm constrained margin around the gross tumor. Unresected tumors, <8 cm at diagnosis, received a standard dose of 55.8 Gy and tumors ≥8 cm, an escalated dose to 64.8 Gy. Patients with microscopic residual disease after resection received adjuvant RT to 50.4 Gy. Adjuvant brachytherapy was permitted in selected patients.

RESULTS

Forty-five patients were enrolled: 26 with localized and 19 with metastatic disease. Median (range) age, tumor size, and follow-up were 13.0 years (2.9-24.7 years), 9.0 cm (2.4-17.0 cm), and 54.5 months (1.9-122.2 months), respectively. All patients received systemic chemotherapy. The median (range) RT dose for all patients was 56.1 Gy (45-65.5 Gy). Seventeen patients received adjuvant, 16 standard-dose, and 12 escalated-dose RT. Failures included 1 local, 10 distant, and 1 local/distant. The estimated 10-year cumulative incidence of local failure was 4.4% ± 3.1%, with no statistical difference seen between RT treatment groups and no local failures in the escalated-dose RT treatment group.

CONCLUSIONS

Treatment with focal conformal, limited margin RT, including dose escalation for larger tumors, provides favorable local tumor control in EWS.

[A 44 year old patient presenting with Ewing's sarcoma of the big toe]

We present the case of a patient with osseous Ewing's sarcoma of the big toe occurring during the healing process after a fracture of the little toe, which significantly delayed diagnosis, despite striking findings on imaging. We subsequently performed further diagnostics, neoadjuvant chemotherapy, tumor resection in the form of a resection of the first ray, and adjuvant chemotherapy. This case shows that the occurrence of a secondary disease should always be considered in untypical courses of healing.

Multimodality Treatment in Ewing's Sarcoma Family Tumors of the Maxilla and Maxillary Sinus: Review of the Literature

The Ewing sarcoma family of tumors (ESFT) encompasses a group of highly aggressive, morphologically similar, malignant neoplasms sharing a common spontaneous genetic translocation that affect mostly children and young adults. These predominantly characteristic, small round-cell tumors include Ewing's sarcoma of the bone and soft tissue, as well as primitive neuroectodermal tumors (PNETs) involving the bone, soft tissue, and thoracopulmonary region (Askin's tumor). Extraosseous ESFTs are extremely rare, especially in the head and neck region, where literature to date consists of sporadic case reports and very small series. We hereby present a review of the literature published on ESFTs reported in the maxilla and maxillary sinus region from 1968 to 2016.

UK guidelines for the management of bone sarcomas

This document is an update of the British Sarcoma Group guidelines published in 2010. The aim is to provide a reference standard for the clinical care of patients in the UK with bone sarcomas. Recent recommendations by the European Society of Medical Oncology, The National Comprehensive Cancer Network and The National Institute for Health and Care Excellence have been incorporated, and the literature since 2010 reviewed. The standards represent a consensus amongst British Sarcoma Group members in 2015. It is acknowledged that these guidelines will need further updates as care evolves. The key recommendations are that bone pain or a palpable mass should always lead to further investigation and that patients with clinico-radiological findings suggestive of a primary bone tumour at any site in the skeleton should be referred to a specialist centre and managed by a fully accredited bone sarcoma multidisciplinary team. Treatment recommendations are provided for the major tumour types and for localised, metastatic and recurrent disease. Follow up schedules are suggested.

Management and Outcome of Ewing Sarcoma of the Head and Neck

BACKGROUND

Ewing sarcoma (EWS) of the head and neck is rare. Multimodal treatment consists of chemotherapy and local treatment; however, local treatment for EWS of the head and neck is challenging. The first objective was to describe local treatment administered to the patients with localized EWS of the head and neck according to the EURO-E.W.I.N.G.99-trial, and to assess the impact on survival. The second objective was to systematically review the scientific literature available for this topic.

PROCEDURE

Fifty-one patients were included. Local control consisted of surgery and/or radiotherapy (RT). Event-free survival (EFS) and overall survival (OS) were determined. Outcome was analyzed by comparing local treatment approaches. A Medline search was performed for EWS of the head and neck.

RESULTS

Eighty-six percent of patients had localized disease. Most common primary sites included the skull (45%), maxilla (14%), and mandible (12%). Three-year EFS was 74% and 3-year OS was 87% for patients with localized disease. EFS was 40% for patients >15 years compared to 81% for patients <15 years. Local control consisted of surgery (S; 33%), RT (18%), or S + RT (45%). Related 3-year EFS was 81% (S), 80% (RT), and 72% (S + RT); 3-year OS was 80%, 76%, and 81%, respectively.

CONCLUSIONS

In patients with EWS of the head and neck, age, and stage are important prognostic factors. Although not statistically significant, large tumor volume seems to be a negative prognostic factor. No difference in EFS and OS could be found when comparing patients treated with surgery, RT, or combined surgery and RT.

Local therapy in non-metastatic primary Ewing sarcoma of the mandible and maxilla in children

Ewing sarcoma (ES) of the jaw bones comprises a small fraction of ES at all sites. Due to their rarity, a specific policy for local treatment is lacking. The aim of this study was to evaluate the local therapy for ES and recommend measures to individualize treatment options. Patients with primary non-metastatic ES of the jaw bones treated between August 2005 and February 2015 were analyzed. All patients received primary induction chemotherapy, following which lesions amenable to resection based on specific radiological criteria were resected; those with unresectable lesions were offered definitive radiotherapy. The maxilla was the primary site in 13 patients and the mandible in eight. The median age of patients was 11.6 years (range 5-17 years). Overall, surgery was performed in 17 patients and definitive radiotherapy was used in four patients. Postoperative radiotherapy was administered to 12 patients and was avoided in five patients with 100% tumour necrosis. The 3-year overall survival, event-free survival, and local control were 68.1%, 63.6%, and 80.2%, respectively. Mandible primary and a histological response to chemotherapy were significant prognostic factors. The stratification of patients based on radiological criteria aids in selecting local therapy. In eligible patients, surgery with contemporary reconstruction results in optimal oncological and functional outcomes. Surgery also has the added advantage of identifying patients who may not need radiotherapy.

The role of radiotherapy in local control of nonextremity Ewing sarcomas

PURPOSE

To evaluate the results of radiotherapy and the prognostic factors affecting local control in nonextremity Ewing sarcomas.

METHODS

Between 1995 and 2011, 44 patients with nonextremity Ewing sarcomas were treated with radiotherapy. Tumor localizations were pelvis in 23, spine in 13, thoracic region in 5, and cranium in 3 patients. Tumor size was ≥8 cm in 56.8% of patients. Distant metastases were present in 19 of the patients at the time of diagnosis (43.1%). All patients were treated with 12 weeks of neoadjuvant chemotherapy followed by surgery and radiotherapy (45-54 Gy) or radiotherapy alone (54-64.8 Gy). Radiotherapy was applied due to microscopic residue (R1) in 5 patients after the operation and macroscopic tumor in 39 patients (macroscopic residue [R2] and nonresectable tumor).

RESULTS

Median follow-up was 49 months (range 9-195). Local failures developed in 7 patients (15.9%) and local control at 5 years was 81.4%. Local recurrence was detected in 6 patients (6/38) who did not have residual tumor after RT. Progression was detected in 1 patient (1/6) who had residual tumor. All those patients with local failure experienced further distant metastases. Possible prognostic factors such as age (≤17 vs &gt;17), tumor localization, tumor volume (≤8 cm vs &gt;8 cm), and M status at diagnosis (0 vs 1) were not related to local control.

CONCLUSIONS

Radiotherapy, either alone or adjuvant to surgery, provides local control in 80% of nonextremity Ewing sarcomas and plays an important role in treatment.

Improved Prognosis for Patients with Ewing Sarcoma in the Sacrum Compared with the Innominate Bones: The Scandinavian Sarcoma Group Experience

BACKGROUND

Treatment of Ewing sarcoma of the pelvic bones remains one of the most difficult tasks in the treatment of bone sarcomas. Whether surgery or radiation therapy is the best local treatment is still a matter of debate. The aim of the present study was to compare sacral and nonsacral sites with regard to the treatment and outcome of pelvic Ewing sarcomas.

METHODS

Patients with Ewing sarcoma of the osseous pelvis diagnosed between 1986 and 2011 were identified through the Scandinavian Sarcoma Group registry. Data regarding tumor size, local treatment (surgery or radiation therapy), metastatic disease, surgical margins, local recurrence, and overall survival were analyzed.

RESULTS

Of the 117 patients examined, eighty-eight had tumors in the innominate bones and twenty-nine, in the sacrum. Radiation therapy was the sole local treatment for 40% of the innominate bone tumors in contrast to 79% of the sacral tumors. The five-year disease-free survival rate in the latter group (66%) was greater than that in the group with tumors in the innominate bones (40%) (p = 0.02 adjusted for size).

CONCLUSIONS

Disease-free survival among patients with Ewing sarcoma was improved when the tumor was localized in the sacrum compared with the innominate bones, where these tumors are generally larger. Local radiation therapy alone appears to result in good local tumor control and may be the treatment of choice for sacral tumors.

Patient-Reported Functional and Quality of Life Outcomes in a Large Cohort of Long-Term Survivors of Ewing Sarcoma

BACKGROUND

Little data exist regarding long-term functional and quality of life (QOL) outcomes for survivors of Ewing sarcoma (ES). Specifically, there are few reports assessing the impact of patient characteristics and local therapy modalities on patient-reported outcomes (PRO).

PROCEDURE

Long-term survivors of ES treated between 1977 and 2009 completed self-assessed functional and QOL surveys, using the Toronto Extremity Salvage Score (TESS) and PEDSQL 4.0 generic core instruments, respectively. Statistical analyses were performed to correlate these outcomes to clinical presentations and treatment regimens.

RESULTS

Subjects (n = 74) with a mean duration from diagnosis of 17.8 years completed the survey. Mean TESS and PEDSQL total scores for the entire cohort were 93.0 ± 10.3 and 81.6 ± 18.0, respectively. No significant differences were appreciated between adult and pediatric patients, although increasing age was associated with lower functional scores (P = 0.04). Mean PEDSQL total scores were significantly lower for female patients (74.6 ± 19.7) compared to males (85.7 ± 15.7) (P = 0.01). Mild to moderate disability was reported by 32% of respondents and was associated with lower TESS and PEDSQL scores. Local control modality did not significantly affect functional and QOL scores. Patients with pelvic tumors had significantly lower TESS scores compared to those with nonpelvic tumors (P = 0.04), especially amongst patients treated with both surgery and radiation.

CONCLUSIONS

Although many survivors of ES report excellent functional and QOL outcomes, a significant number report long-term disability and impairments. Older patients, females, and those with pelvic primary tumors appear at the greatest risk for long-term decrements and may benefit from early therapeutic interventions.

Extraosseous Ewing Sarcoma: Diagnosis, Prognosis and Optimal Management

Extraosseous Ewing sarcomas (EESs) are rare tumours originating from soft tissues. Their clinical picture depends mainly on the primary site of the sarcoma. Patient characteristics and outcomes seem to be different in EES compared to patients with skeletal Ewing sarcoma, with implications for patient care and prognosis. However, multimodality therapeutic strategies are recommended for all types of the Ewing tumour family. The available diagnostic tools include ultrasonographic evaluation and computed tomography (CT) or magnetic resonance imaging as well as histopathologic and immunohistochemical tissue examination. Several histologic and genetic biomarkers have been established, although their utilization needs to be further tested by larger prospective studies. Regarding localized disease, the recommended treatment remains surgery. However, chemotherapy can be added to achieve improved survival, with neoadjuvant regimens showing more promising results than adjuvant regimens. Radiotherapy is an option to obtain local control, although its complications have reduced its utilization. In metastatic or recurrent disease, systematic chemotherapy improves survival.

The effect of surgery with radiation on pelvic Ewing sarcoma survival

BACKGROUND

Pelvic Ewing sarcoma (ES) has poorer outcomes than extremity-based lesions and the method of local control is controversial.

METHODS

A retrospective review was performed of 40 primary pelvic or sacral ES treated by a single surgeon. All received modern chemotherapy and those that received radiation were treated with modern dosages.

RESULTS

Fifty-five percent were disease-free at latest follow-up (median, 83.1 mos). Sixty-one percent had ≥ 99% necrosis, which was associated with 65% disease-free survival. Larger size (P = 0.016) and the absence of metastatic disease (P = 0.005) was predictive of survival. Eighty-three percent of relapsed patients were DOD. Half of patients who received surgery alone or RT alone have NED while 57% of those who received S/RT have NED. Complication rates were 69% (S/RT), 75% (surgery alone), 10% (RT alone). Functional outcomes were similar.

CONCLUSION

Primary pelvic ES is localized at presentation in 50% and the absence of metastases is the strongest predictor for survival. Chemotherapy is key, but excellent histologic response is neither a guarantee nor a necessity for survival. More than one-third die despite an excellent histologic response and at least one-third with lung metastases survive. With chemotherapy, radiation, and surgery, reasonable control of disease can be achieved.

LEVEL OF EVIDENCE III

Case-control or retrospective cohort study.

Ewing Sarcoma: Current Management and Future Approaches Through Collaboration

Ewing sarcoma (ES) is an aggressive sarcoma of bone and soft tissue occurring at any age with a peak incidence in adolescents and young adults. The treatment of ES relies on a multidisciplinary approach, coupling risk-adapted intensive neoadjuvant and adjuvant chemotherapies with surgery and/or radiotherapy for control of the primary site and possible metastatic disease. The optimization of ES multimodality therapeutic strategies has resulted from the efforts of several national and international groups in Europe and North America and from cooperation between pediatric and medical oncologists. Successive first-line trials addressed the efficacy of various cyclic combinations of drugs incorporating doxorubicin, vincristine, cyclophosphamide, ifosfamide, etoposide, and dactinomycin and identified prognostic factors now used to tailor therapies. The role of high-dose chemotherapy is still debated. Current 5-year overall survival for patients with localized disease is 65% to 75%. Patients with metastases have a 5-year overall survival < 30%, except for those with isolated pulmonary metastasis (approximately 50%). Patients with recurrence have a dismal prognosis. The many insights into the biology of the EWS-FLI1 protein in the initiation and progression of ES remain to be translated into novel therapeutic strategies. Current options and future approaches will be discussed.

The Neurological Compromised Spine Due to Ewing Sarcoma. What First

BACKGROUND:

The vertebral column is an infrequent site of primary involvement in Ewing sarcoma. Yet when Ewing sarcoma is found in the spine, the urge for decompression is high because of the often symptomatic compression of neural structures. It is unclear in alleviating a neurological deficit whether chemotherapy is preferred over decompressive laminectomy.

OBJECTIVE:

To underline, in this case series, the efficiency of initial chemotherapy before upfront surgery in the setting of high-grade spinal cord or cauda equina compression of primary Ewing sarcoma.

METHODS:

Fifteen patients with Ewing sarcoma primarily located in the spine were treated at our institution between 1983 and 2015. Localization, neurological deficit expressed as Frankel grade, and outcome expressed as Rankin scale before and after initial chemotherapy, the recurrence rate, and overall survival were evaluated. The multidisciplinary approach of 1 case will be discussed in detail.

RESULTS:

Nine patients (60%) were female. The age at presentation was 15.0 ± 5.5 years (range: 0.9–22.8 years). Ten patients (67%) were initially treated with chemotherapy, and 1 patient (7%) was treated primarily with radiotherapy followed by chemotherapy. The remaining 4 patients (27%) were initially treated with decompressive surgery. All patients treated primarily nonsurgically improved neurologically at follow-up, showing the importance of chemotherapy as an effective initial treatment option.

CONCLUSION:

Adequate and quick decompression of neural structures with similar results can be achieved by chemotherapy and radiotherapy, avoiding the local spill of malignant cells.

Developing a prognostic model for localized Ewing sarcoma family of tumors: A single institutional experience of 224 cases treated with uniform chemotherapy protocol

BACKGROUND

Data on patients with localized Ewing sarcoma family of tumors (ESFT) who have received a uniform chemotherapy protocol are minimal.

METHODS

This is a single institutional review of patients with ESFT treated between June 2003 and November 2011.

RESULTS

224/374 (60%) patients with ESFT presented with localized disease; median age was 15 years (range: 0.1-55). Ninety-nine patients underwent surgery of which 50 received adjuvant radiotherapy; 80 patients received radical radiotherapy following neoadjuvant chemotherapy. At median follow-up of 40.2 months (range: 1.3-129), 5-year EFS, OS, and local-control-rate, were 36.8 ± 3.6%, 52.4 ± 4.3%, and 63 ± 4.3%, respectively. In multivariate analysis, tumor diameter > 8 cm (P = 0.03), symptom duration > 4 months (P = 0.04), and WBC > 11 × 10(9) /L (P = 0.003) predicted inferior EFS; spine/abdomino-pelvic primary (P = 0.009) and WBC > 11 × 10(9) /L (P = 0.003) predicted inferior OS. Tumor size > 8 cm (P = 0.03) and radical radiotherapy as local treatment (P = 0.01) predicted inferior local-control-rate.

CONCLUSION

Prognostic hazard models for EFS and OS based on significant prognostic factors suggested that patients with combination of ESFT of spine/abdomino-pelvic region and baseline WBC > 11 × 10(9) /L had inferior OS (hazard ratio 4.44, P < 0.001) while patients with combination of ESFT with symptom duration > 4 months, tumor diameter > 8 m and baseline WBC > 11 × 10(9) /L had inferior EFS (hazard ratio 3.89, P = 0.002).

[Resection margins in bone tumors: what is adequate?]

BACKGROUND

In multimodal therapy concepts for bone sarcomas, tumor resection is a deciding factor. Modern imaging techniques have made preoperative resection planning much easier and precisely allow tumor boundaries to be defined.

OBJECTIVES

There is recent data clearly showing that compartmental resections have no significant advantages compared to wide resections in terms of local recurrence or overall survival. But it remains unclear, how "wide" a "wide resection" should be done.

MATERIALS AND METHODS

A literature review of the last 15 years, discussion of review articles and multidisciplinary expert opinions as published in major multinational studies.

RESULTS

Intralesional resection (R1) is feasible in highly differentiated (G1) chondrosarcoma (atypical cartilaginous tumor) of the extremity. In both osteosarcoma and Ewing's sarcoma, R0 resection is mandatory. If these fails, there is evidence that in selected cases of osteosarcoma, adjuvant radiotherapy is justified if a second resection is not possible. Expecting contaminated (R1) margins in patients with Ewing's sarcoma (e.g., in critical locations such as the pelvis), radiotherapy only is better than hoping for the "cure" of insufficient resections margins with a combination of both methods. With regard to the necessary safety distances for a R0 resection, recommendations from the literature are heterogeneous. In addition to the distance measurement, the quality of the anatomic resection margins (e.g., fascia) is of great importance. A distinct recommendation of at least x millimeters or centimeters cannot be given based on the currently available data.

CONCLUSION

The aim of the resection of a bone sarcoma should be a wide margin with the exception of chondrosarcoma (G1). Ultraradical resections which sacrifice vital structures in order to extend an already wide (R0) resection margin showed no significant benefits. In patients with osteosarcoma, adjuvant radiotherapy should be considered if resection or re-resection is not in sound tissue (R1). Patients with Ewing's sarcoma should not undergo resection if a contaminated margin is expected. In patients with chondrosarcoma, the available data as for example from pelvic tumors are contradictory and do not allow a clear recommendation.

Is total en bloc sacrectomy using a posterior-only approach feasible and safe for patients with malignant sacral tumors?

OBJECT In this study the authors' aim was to describe their experience with total en bloc sacrectomy using a posterioronly approach and to assess the outcome of patients with malignant sacral tumors who underwent this procedure at their center. METHODS The authors identified and retrospectively reviewed the records of 10 patients with malignant sacral tumors who underwent a total en bloc sacrectomy via a single posterior approach at their center. The pathological diagnosis was chordoma in 4 patients, chondrosarcoma in 1, osteosarcoma in 1, malignant schwannoma in 1, malignant giant cell tumor in 1, and Ewing's sarcoma in 2. Radiological examination revealed that the tumor involved S1-5 in 7 patients, S1-4 in 1, S1-3 in 1, and S1-2 in 1. RESULTS All 10 patients were stable during the perioperative period. The mean surgery duration was 282 minutes (range 250-310 minutes). The median estimated blood loss was 2595 ml (range 1500-3200 ml). All patients were followed up for 13-29 months (mean 22 months). Two patients had a local recurrence. Two patients died of disease, 1 patient was alive with disease, and 7 patients were alive without evidence of disease. Among the 8 surviving patients, 6 were able to walk without assistive devices, and 2 were able to walk with crutches. The total complication rate was 40% (4 of 10). Wound complications (deep infection and wound healing problems) occurred in 3 patients, and a distal deep vein thrombosis occurred in 1 patient. CONCLUSIONS Total en bloc sacrectomy using a posterior-only approach is feasible and safe in selected patients and is an important procedure for the treatment of primary malignant tumor involving the entire sacrum or only the top portion.

Surgically treated patients with axial and peripheral Ewing's sarcoma family of tumours: A population based study in Finland during 1990-2009

BACKGROUND

The surgical treatment of Ewing's sarcoma family tumours (ESFTs) is challenging especially with axial tumours. The aim of the study was to analyse surgical treatment and outcome in a nationwide, population-based material consisting of surgically treated axial and peripheral ESFTs of bone and soft tissue.

METHODS

The data were collected from the Finnish National Cancer Registry and the medical records of patients diagnosed during 1990-2009. Fifty-seven patients with surgically treated ESFTs were included, 22 with an axial and 35 with a peripheral primary tumours. The surgical treatment, its complications, survival and prognostic factors were analysed.

RESULTS

Fifty-four patients underwent surgery with a curative intent and three underwent de-bulking operations. Bone reconstruction was performed in six patients with an axial and 15 with a peripheral tumour. Positive resection margins were associated with a worse five-year local relapse-free survival (33% vs. 84% for those with resection margins free of tumour cells, p = 0.003). The five-year sarcoma-specific survival was affected only by an axial location of the primary (61% vs. 89% for those with a peripheral tumour, p = 0.031). The late complications were mainly associated with bone reconstruction and more frequent among patients with a peripheral compared to an axial tumour (p = 0.031).

CONCLUSIONS

In the treatment of ESFTs, achieving adequate resection margins is crucial to avoid local relapses. Surgical complications are common particularly with bone reconstruction.

Oncogenic fusion protein EWS-FLI1 is a network hub that regulates alternative splicing

The synthesis and processing of mRNA, from transcription to translation initiation, often requires splicing of intragenic material. The final mRNA composition varies based on proteins that modulate splice site selection. EWS-FLI1 is an Ewing sarcoma (ES) oncoprotein with an interactome that we demonstrate to have multiple partners in spliceosomal complexes. We evaluate the effect of EWS-FLI1 on posttranscriptional gene regulation using both exon array and RNA-seq. Genes that potentially regulate oncogenesis, including CLK1, CASP3, PPFIBP1, and TERT, validate as alternatively spliced by EWS-FLI1. In a CLIP-seq experiment, we find that EWS-FLI1 RNA-binding motifs most frequently occur adjacent to intron-exon boundaries. EWS-FLI1 also alters splicing by directly binding to known splicing factors including DDX5, hnRNP K, and PRPF6. Reduction of EWS-FLI1 produces an isoform of γ-TERT that has increased telomerase activity compared with wild-type (WT) TERT. The small molecule YK-4-279 is an inhibitor of EWS-FLI1 oncogenic function that disrupts specific protein interactions, including helicases DDX5 and RNA helicase A (RHA) that alters RNA-splicing ratios. As such, YK-4-279 validates the splicing mechanism of EWS-FLI1, showing alternatively spliced gene patterns that significantly overlap with EWS-FLI1 reduction and WT human mesenchymal stem cells (hMSC). Exon array analysis of 75 ES patient samples shows similar isoform expression patterns to cell line models expressing EWS-FLI1, supporting the clinical relevance of our findings. These experiments establish systemic alternative splicing as an oncogenic process modulated by EWS-FLI1. EWS-FLI1 modulation of mRNA splicing may provide insight into the contribution of splicing toward oncogenesis, and, reciprocally, EWS-FLI1 interactions with splicing proteins may inform the splicing code.

Diagnosis and treatment of Ewing sarcoma of the bone: a review article

Ewing sarcoma (ES) is rare in Japanese people, and only 30-40 patients develop the disease annually. To diagnose ES, molecular techniques that aim to detect characteristic fusion genes are commonly used in combination with conventional histological and immunohistochemical examinations. The treatment strategy for ES is characterized by multi-disciplinary collaboration between pediatric oncologists, medical oncologists, radiation oncologists, and orthopedic surgeons. In recent years, numerous large-scale national or international multi-institutional studies of ES have been performed. Pre- and postoperative intensive systemic chemotherapy with multiple anticancer drugs is the standard treatment method for ES. Depending on the obtained surgical margin, postoperative radiation might also be performed. If preoperative radiological examinations indicate that surgical excision would be difficult, preoperative radiation can be administered. As the treatment outcomes of ES have improved, late complications and secondary malignancies have become a problem. After treatment, patients with ES require very long-term follow-up in order to detect secondary malignancies and growth-related musculoskeletal complications.

Do patients with ewing's sarcoma continue with sports activities after limb salvage surgery of the lower extremity?

BACKGROUND

Limb salvage surgery has evolved to become the standard method of treating sarcomas of the extremities with acceptable oncologic results. However, little information exists relative to the activity level or ability to participate in sports after tumor reconstructions.

QUESTIONS/PURPOSES

The aims of the study were to answer the following questions: (1) Which sports activity levels and what types of sports can be expected in the long term after tumor reconstruction? (2) Which frequency durations are patients with Ewing's sarcoma able to perform in long-term followup after local control? (3) Do surgical complications affect sports activity level?

METHODS

Thirty patients (13 females, 17 males; mean age, 18 ± 8 years; range, 2-36 years at diagnosis; mean followup 16 ± 6 years [minimum, 5 years]) were included. Tumors were located in the pelvis, femur, tibia, and fibula. Surgical procedures included surgical resections alone (n = 8), surgical resection with biological reconstruction (n = 9), or endoprosthetic reconstruction (n = 13). We assessed UCLA sports activity levels, kinds of sports as well as the frequency per week and the duration of each training unit at long term (minimum followup, 5 years).

RESULTS

In long-term followup 83% patients (25 of 30) were performing athletic activity regularly. The hours/week of sports depended on type of surgery and were highest after resections in the pelvis and femur (5.8) and were lowest after megaprosthetic reconstruction of the pelvis (1.0). Patients undergoing biologic reconstructions were able to perform high-impact sports. UCLA sports activity levels were high after joint-preserving vascularized fibula for tibia reconstruction (7.4) and after megaprosthetic reconstruction of the lower extremity (6.3-6.4) and were low after tumors located in the fibula (4.2). Complications during followup did not significantly influence sports activity in long-term survivors.

CONCLUSIONS

Long-term survivors can achieve high levels of sports activity in many instances. Tumor sites are associated with the postoperative sports activity levels. This information can help surgeons counsel patients in terms of athletic expectations after limb salvage reconstruction for patients with Ewing's sarcoma.

LEVEL OF EVIDENCE

Level III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Radiation for bone metastases in Ewing sarcoma and rhabdomyosarcoma

BACKGROUND

The role, optimal dose, and efficacy of radiotherapy (RT) for the treatment of bone metastases in rhabdomyosarcoma (RMS) and Ewing sarcoma (ES) are unclear.

PROCEDURE

All patients with ES or RMS who received RT for bone metastases with curative intent during frontline therapy at Memorial Sloan Kettering Cancer Center (MSKCC) between 1995 and 2013 were reviewed. Among the 30 patients (8 RMS and 22 ES), 49 bone metastases were irradiated.

RESULTS

Median biologically effective dose (BED) was 42.4 Gy (range, 34.9-59.7) for RMS and 50.7 Gy (range, 31.3-65.8) for ES. Tumor recurrence occurred in six of 49 irradiated bone metastases. Cumulative incidence of local failure at a treated metastatic site was 6.6% at 1 year and 9.0% at 3 years. Dose, fractionation, and RT technique did not impact local control at an irradiated site. The presence of >5 bone metastases was associated with worse local control at an irradiated site (P = 0.07). The 3-year EFS was 33% in RMS and 16% in ES.

CONCLUSIONS

RT appears to be an effective modality of local control for bone metastases in ES and RMS. Local control at sites of metastatic bone irradiation is similar to local control at the primary site after definitive RT. Doses in the biologic range prescribed for the definitive treatment of primary disease should be used for metastatic sites of disease.

Role of Radiotherapy in the Multimodal Treatment of Ewing Sarcoma Family Tumors

Purpose

The aim of this study was to evaluate the role of radiotherapy (RT) in the management of Ewing sarcoma family tumors (ESFT).

Materials and Methods

Retrospective analysiswas performed on 91 patientswith localized ESFT treated from 1988 to 2012. Primary tumor size was ≥ 8 cm in 33 patients. Surgery, RT, and combined surgery with RT were applied in 37, 15, and 33 patients, respectively.

Results

Median follow-up was 43.8 months. Forty-three patients (47.3%) showed recurrence or progressive disease. Twelve patients (13.2%) showed local failure after initial treatment. Thirty-nine patients (42.9%) experienced distant metastases. The 5-year overall survival (OS), progression-free survival, and local control (LC) were 60.5%, 58.2%, and 85.1%, respectively. According to treatment, 5-year LCwas 64.8% with RT and 90.2% with combined surgery and RT (p=0.052). Prognostic factors for OS were tumor size (≥ 8 cm, p < 0.001) and surgical resection (p < 0.001). In large tumors (≥ 8 cm), combined surgery and RT produced better LC compared to RT (p=0.033). However, in smaller tumors (< 8 cm), RT without surgery resulted in a similar LC rate as RT with surgery (p=0.374).

Conclusion

RT used for patients with unfavorable risk factors resulted in worse outcome than for patientswho received surgery. Smallertumors could be controlled locallywith chemotherapy and RT. For large tumors, combined surgery and RT is needed. Proper selection of local treatment modality, RT, surgery, or both is crucial in the management of ESFT.

Validation of a multi-modal treatment protocol for Ewing sarcoma--a report from the polish pediatric oncology group

BACKGROUND

Ewing sarcoma (ES) is the second most common paediatric malignant bone tumor. Advances in multi-disciplinary care have resulted in significant improvement in cure rates over the last decades. However, the generalization of those results in countries traditionally excluded from large cooperative trials has yet to be demonstrated. We report the results of modern multi-disciplinary care for patients with ES in Poland.

PROCEDURES

One hundred and thirty-two patients with ES were treated using modern multi-modal therapy during the period 2000-2009. Overall survival was estimated by Kaplan-Meier methods and compared using long-rank test and Cox models. Factors predictive of outcome in our setting were analyzed to identify distinct risk groups that could help identify areas for improvement.

RESULTS

The median age at the time of diagnosis was 12.3 years. With a median follow-up of 5.0 years, the 5-year event-free survival (EFS) and OS estimates for localized disease were 54.88% and 68.29%, respectively. For patients with metastatic disease, 5-year EFS and OS estimates were 36% and 42%, respectively. There was no correlation between age and stage or site. Patients with localized, non-pelvic disease had better outcome than patients with axial tumors (71% vs. 44%, respectively, P = 0.00073). Treatment failure was associated with stage, pelvic primary, poor histological response, and type of local control.

CONCLUSIONS

Successful treatment of ES requires optimal systemic and local therapy. We were able to replicate the results of modern multi-modal protocols. Validation of current treatment protocols in countries with more limited cancer treatment resources is required.

Ewing sarcoma in adults treated with modern radiotherapy techniques

BACKGROUND AND PURPOSE

To evaluate local control and survival outcomes in adults with Ewing sarcoma (ES) treated with radiotherapy (RT).

MATERIAL AND METHODS

Retrospective review of all 109 patients age ⩾18 treated for ES with RT to the primary site at Memorial Sloan Kettering Cancer Center between 1990 and 2011. RT was used as the definitive local control modality in 44% of patients, preoperatively for 6%, and postoperatively for 50%.

RESULTS

Median age at diagnosis was 27years (range, 18-67). The 5-year local failure (LF) was 18%. Differences in LF were not identified when evaluated by modality of local control (RT versus combined surgery and RT), RT dose, fractionation, and RT technique. However, margin status at time of resection significantly predicted LF. The 5-year event-free survival and overall survival rates were 44% and 66% for patients with localized disease, compared with 16% and 26% for metastatic disease (p=0.0005 and 0.0002). Tumor size, histopathologic response to chemotherapy, and treatment on or according to a protocol were also significantly associated with survival.

CONCLUSIONS

This series of adults treated with modern chemotherapy and RT had prognostic factors and outcomes similar to adolescents with ES. All adults with ES should be treated with an aggressive, multidisciplinary approach.

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

BACKGROUND

Patients with Ewing sarcoma require local primary tumor control with surgery, radiation, or both. The optimal choice of local control for overall and local disease control remains unclear.

METHODS

Patients with localized Ewing sarcoma of bone who were treated on 3 consecutive protocols with standard-dose, 5-drug chemotherapy every 3 weeks were included (n=465). Propensity scores were used to control for differences between local control groups by constructing multivariate models to assess the impact of local control type on clinical endpoints (event-free survival [EFS], overall survival, local failure, and distant failure) independent of differences in their propensity to receive each local control type.

RESULTS

Patients who underwent surgery were younger (P=.02) and had more appendicular tumors (P<.001). Compared with surgery, radiation had higher unadjusted risks of any event (hazard ratio [HR], 1.70; 95% confidence interval [CI], 1.18-2.44), death (HR, 1.84; 95% CI, 1.18-2.85), and local failure (HR, 2.57; 95% CI, 1.37-4.83). On multivariate analysis, compared with surgery, radiation had a higher risk of local failure (HR, 2.41; 95% CI, 1.24-4.68), although there were no significant differences in EFS (HR, 1.42; 95% CI, 0.94-2.14), overall survival (HR, 1.37; 95% CI, 0.83-2.26), or distant failure (HR, 1.13; 95% CI, 0.70-1.84) between local control groups.

CONCLUSIONS

In this large group of similarly treated patients, choice of the mode of local control was not related significantly to EFS, overall survival, or distant failure, although the risk of local failure was greater for radiation compared with surgery. These data support surgical resection when appropriate, whereas radiotherapy remains a reasonable alternative in selected patients.

Primary non-metastatic Ewing sarcoma of the jaw in children: results of surgical resection and primary reconstruction

BACKGROUND AND OBJECTIVE

The rarity of Ewing sarcoma (ES) of the jaw coupled with the technical challenge of resection and associated functional and cosmetic impairment has resulted in deficient data on surgical management of these tumors. The purpose of this study is to describe the results of surgical excision and reconstruction of primary non-metastatic ES of the mandible and maxilla in children.

METHODS

Consecutive patients (mandible = 6, maxilla = 5) treated with surgery from August 2005 to January 2013 were selected. All patients received induction chemotherapy and were selected for surgical resection based on the presence of specific criteria for operability.

RESULTS

The median age was 11.5 years (range 5-16 years). Free fibular osteocutaneous flap was commonly used for reconstruction. There were no complications related to microvascular anastomosis or flap loss. Five patients had 100% tumor necrosis and did not receive radiotherapy. Teeth alignment, chewing, swallowing, and speech were normal in all and donor site morbidity occurred in one. The 5-year overall, event-free survival, and local control are 87.5%, 72.9%, and 90%, respectively.

CONCLUSION

In eligible patients, surgery with contemporary reconstruction results in optimal oncological and functional outcome. Surgery also has the added advantage of identifying patients who may not need radiotherapy.

Outcomes and prognostic factors for Ewing-family tumors of the extremities

BACKGROUND

There are few published studies describing the clinical results of patients uniformly treated for a Ewing-family tumor of an extremity.

METHODS

We performed a review of patients who had received uniform treatment consisting of neoadjuvant chemotherapy, surgery and/or radiation therapy as local treatment, and then adjuvant chemotherapy from June 2003 to November 2011 at a single institution.

RESULTS

There were 158 patients included in the study. The median age was fifteen years. Sixty-nine (44%) of the patients had metastatic disease at presentation. Fifty-seven patients underwent surgery, and forty-one received radical radiation therapy following neoadjuvant chemotherapy. After a median of 24.3 months (range, 1.6 to ninety-seven months) of follow-up, the five-year event-free survival, overall survival, and local control rates (and standard error) were 24.1% ± 4.3%, 43.5% ± 6%, and 55% ± 6.8%, respectively, for the entire cohort and 36.4% ± 6.2%, 57.6% ± 7.4%, and 58.2% ± 7.9%, respectively, for patients without metastases. In the multivariate analysis, metastases predicted inferior event-free survival (p = 0.02) and overall survival (p = 0.03) rates in the entire cohort, whereas radical radiation therapy predicted an inferior local control rate in the entire cohort (p = 0.001) and in patients without metastases (p = 0.04). In the group with localized disease, there was no difference between the patients who received radical radiation therapy and those who underwent surgery with regard to tumor diameter (p = 0.8) or post-neoadjuvant chemotherapy response (p = 0.1). A white blood cell count (WBC) of >11 × 109/L predicted inferior event-free survival (p = 0.005) and local control (p = 0.02) rates for patients without metastases.

CONCLUSIONS

To our knowledge, this is the largest study on extremity Ewing-family tumors treated with uniform chemotherapy and either surgical resection or radical radiation therapy in Asia. All possible efforts should be made to resect a primary tumor after neoadjuvant chemotherapy, as radical radiation therapy alone results in a poor local control rate despite a good post-neoadjuvant chemotherapy response. Patients without metastases but with a high WBC had inferior event-free survival and local control rates and may require more aggressive therapy.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Progress in musculoskeletal oncology from 1922 - 2012

Since 1922 surgical approaches toward limb salvage in bone and soft tissue tumours have been documented. There is the famous "Umkippplastik" of Sauerbruch, the "Tikhoff-Linberg" inter-scapulo-thoracic resection or in 1943 a metallic tumour prosthesis for the hip joint in the United States (Moore, Bohlman). Since 1960 acrylic prostheses and metallic prosthesis with bone cement have been in use. Cement-free implants and the first modular ceramic prostheses were implanted in the 1970s in Vienna. At the same time successful chemotherapy in bone sarcomas was introduced by Gerald Rosen and Norman Jaffe. This was mainly the decade of custom-made prostheses. In the 1980s modular tumour prostheses with cone connection to be adopted to the needs of the patient were built intra-operatively. Since 1981 biannual international meetings (ISOLS) have pushed forward the field of bone tumour treatment to allow also tumour resection in wide borders for spine and pelvic tumours. New hope for resistant tumours could be monoclonal antibodies or even dendritic cell therapy.

Proton radiotherapy for pediatric sarcoma

Pediatric sarcomas represent a distinct group of pathologies, with approximately 900 new cases per year in the United States alone. Radiotherapy plays an integral role in the local control of these tumors, which often arise adjacent to critical structures and growing organs. The physical properties of proton beam radiotherapy provide a distinct advantage over standard photon radiation by eliminating excess dose deposited beyond the target volume, thereby reducing both the dose of radiation delivered to non-target structures as well as the total radiation dose delivered to a patient. Dosimetric studies comparing proton plans to IMRT and 3D conformal radiation have demonstrated the superiority of protons in numerous pediatric malignancies and data on long-term clinical outcomes and toxicity is emerging. In this article, we review the existing clinical and dosimetric data regarding the use of proton beam radiation in malignant bone and soft tissue sarcomas.

Evaluation of outcome and prognostic factors in thoracic primitive neuroectodermal tumor: a study of 84 cases

BACKGROUND

Data on thoracic primitive neuroectodermal tumor (PNET) treated with a uniform chemotherapy protocol are minimal in the literature. We analyzed patients with thoracic PNET for outcome and prognostic factors.

METHODS

This is a single-institutional data review of patients treated between June 2003 and November 2011 with uniform neoadjuvant chemotherapy, surgical intervention, or radiotherapy (RT), or a combination of these treatments as local therapy followed by adjuvant chemotherapy.

RESULTS

Thoracic PNET was found in 84 of 374 (22%) patients with PNET with a median age of 15 years (range, 3-40 years); 27 (32%) of these patients had metastases. Thirty patients underwent surgical resection; 27 patients received radical RT after neoadjuvant chemotherapy. The radical RT group did not have adverse tumor characteristics or poor response to neoadjuvant chemotherapy. At median follow-up of 20.8 months (range, 2-104.6 months), 5-year event-free survival (EFS), overall survival (OS), and local control rate (LCR) were 24.4% ± 5.9%, 47.9% ± 8.4%, and 59.3% ± 9%, respectively, for the entire cohort, and 31% ± 7.7%, 59% ± 10.4%, and 67% ± 9.7%, respectively, for the group with localized tumors. In multivariate analysis, symptom duration longer than 4 months (p = 0.03), primary tumor of skeletal origin (p = 0.03), and radical RT (p = 0.006) predicted inferior EFS in the entire cohort and those with localized disease; metastatic disease (p = 0.002) predicted inferior OS. Radical RT predicted inferior LCR in the entire cohort and the group with localized tumor; tumor diameter larger than 8 cm (p = 0.02) and symptom duration longer than 4 months (p = 0.02) predicted inferior LCR in the group with localized tumor.

CONCLUSIONS

This is a single-institutional experience of 84 patients with thoracic PNETs who underwent a uniform chemotherapy protocol. Novel prognostic factors were identified for thoracic PNET. All efforts should be made to resect primary tumor after neoadjuvant chemotherapy because radical RT results in inferior EFS and LCR despite good response to neoadjuvant chemotherapy.

Extraskeletal Ewing sarcoma in children and adolescents: impact of narrow but negative surgical margin

PURPOSE

The aim of the study was to determine the impact of negative but close resection margins on local recurrence in children with extraskeletal Ewing sarcoma (EES).

METHOD

We reviewed records of 32 patients with EES treated between March 2005 and March 2013. All patients except one underwent surgical excision either upfront or after induction chemotherapy. Patients with viable tumor and negative surgical margins, which were categorized as less than or greater than 1 cm, were selected. Local control and survival analysis were performed for patients in both the groups.

RESULTS

The 5-year event-free and overall survival rates of entire cohort is 68 and 77 %, respectively. Surgical margins were negative in 23/26 (90.3 %) patients. There were no local recurrences in any of the patients with margins of less than 1 cm. Only one patient with a margin greater than 1 cm had a local recurrence along with distant metastases. A tumor-free margin of more than 1 cm did not affect overall or event-free survival (p = NS).

CONCLUSION

Optimal local control is feasible in children with EES regardless of the quantitative extent of negative margins. Achieving a three-dimensional tumor-free margin should be the goal of surgical resection.

Treatment of an Askin tumor: A case report and review of the literature

Askin tumors are rare malignant neoplasms that are localized in the thoracopulmonary region and mainly occur in children and adolescents. Further investigation with regard to the effective treatment of this disease is required, since the disease has a low incidence and limited knowledge is available on the biological activity and prognostic factors of this type of tumor. The present study describes the case of a 30-year-old male patient with a histologically and morphologically proven Askin tumor who was treated in Shandong Cancer Hospital and Institute (Jinan, China). A chest computed tomography (CT) scan demonstrated a large mass filling the entire left lung, associated with mediastinum and right lung compression and accompanied by destruction of the 2nd rib. The patient accepted chemotherapy and radiotherapy instead of a radical mass resection since the mass was irresectable. A good clinical response was achieved to the chemotherapy and radiotherapy. The diagnosis and treatment of Askin tumors remains a challenge for clinicians and surgeons due to the absence of standard therapeutic guidelines for the treatment of this disease. According to the experience obtained from the cases encountered to date, treatment strategies should aim to reduce local recurrence and distant metastasis. Moreover, surgery, chemotherapy and radiotherapy or a combination of these methods appears to constitute an effective treatment strategy for Askin tumors.

Drugs targeting the bone microenvironment: new therapeutic tools in Ewing's sarcoma?

INTRODUCTION

Ewing's sarcoma (ES) is the second most frequent malignant primary bone tumour in children, adolescents and young adults. The overall survival is 60 - 70% at 5 years but still very poor for patients with metastases, disease relapse or for those not responding to chemotherapy. For these high risk patients, new therapeutic approaches are needed beyond conventional therapies (chemotherapy, surgery and radiation) such as targeted therapies.

AREAS COVERED

Transcriptomic and genomic analyses in ES have revealed alterations in genes that control signalling pathways involved in many other cancer types. To set up more specific approaches, it is reasonable to think that the particular microenvironment of these bone tumours is essential for their initiation and progression, including in ES. To support this hypothesis, preclinical studies using drugs targeting bone cells (bisphosphonate zoledronate, anti-receptor activator of NF-κB ligand strategies) showed promising results in animal models. This review will discuss the new targeted therapeutic options in ES, focusing more particularly on the ones modulating the bone microenvironment.

EXPERT OPINION

Targeting the microenvironment represents a new option for patients with ES. The proof-of-concept has been demonstrated in preclinical studies using relevant animal models, especially for zoledronate, which induced a strong inhibition of tumour progression in an orthotopic bone model.

Relevance of historical therapeutic approaches to the contemporary treatment of pediatric solid tumors

Children with solid tumors, most of which are malignant, have an excellent prognosis when treated on contemporary regimens. These regimens, which incorporate chemotherapeutic agents and treatment modalities used for many decades, have evolved to improve relapse-free survival and reduce long-term toxicity. This review discusses the evolution of the treatment regimens employed for management of the most common solid tumors, emphasizing the similarities between contemporary and historical regimens. These similarities allow the use of historical patient cohorts to identify the late effects of successful therapy and to evaluate remedial interventions for these adverse effects.

Adult ewing sarcoma: survival and local control outcomes in 102 patients with localized disease

Objectives. To assess the clinical features and local control (LC) outcomes in adult patients with localized Ewing Sarcoma (ES). Methods. The records of 102 ES patients with localized disease ≥18 years of age seen from 1977 to 2007 were reviewed. Factors relevant to prognosis, survival, and LC were analyzed. Results. The 5-year overall survival (OS) and event-free survival (EFS) were 60% and 52%, respectively, for the entire cohort. Treatment era (1977–1992 versus 1993–2007) remained an independent prognostic factor for OS on multivariate analysis, with improved outcomes observed in the 1993–2007 era (P = 0.02). The 5-year OS and EFS for the 1993–2007 era were 73% and 60%, respectively. Ifosfamide and etoposide based chemotherapy and surgery were more routinely used in the 1993–2007 era (P < 0.01). The 5-year local failure rate (LFR) was 14%, with a 5-year LFR of 18% for surgery, 33% for radiation, and 0% for combined surgery and radiation in the 1993–2007 era (P = 0.17). Conclusion. Modern survival outcomes for adults with localized ES are similar to multi-institutional results in children. This improvement over time is associated with treatment intensification with chemotherapy and increased use of surgery. Aggressive LC (combined surgery and radiation) may improve outcomes in poor prognosis patients.

Renal Ewing tumors

BACKGROUND

Renal Ewing's sarcoma/primitive neuroectodermal tumor (ES/PNET) is extremely rare. Clinical symptoms are nonspecific presenting abdominal pain, palpable mass, and hematuria. Owing to advanced technology demonstrating the ES-specific EWS/ETS translocation, this differential diagnosis has become feasible.

PATIENTS AND METHODS

The German database of GPOH Ewing's sarcoma trials from 1980 to 2009 was searched for kidney as primary site. Twenty-four patients were identified and analyzed. The median time of observation was 3.71 years (range 0.27-8.75 years). Additionally, we carried out a Medline search for renal ES/PNET.

RESULTS

The median age was 24.9 years (range 11-60 years). In 37.5%, patients presented with primary metastases. Tumor thrombi in the adjacent renal vessels occurred in 56.2%. In 90.9%, rearrangements of t(11;22) were found. All patients received a combined chemotherapy according to the EURO-E.W.I.N.G.99 protocol. In accordance, local control consisted predominantly of combined modality surgery and radiation (47%). At 3 years, overall survival (OS) was 0.80 (SE = 0.09), and event-free survival (EFS) 0.66 (SE = 0.11).

CONCLUSIONS

ES/PNET should be considered in the differential diagnosis of renal tumors. Patients with renal ES/PNET respond to and benefit from conventional ES treatment according to ES study protocols. Therefore, an accurate diagnostic approach and a guideline-adapted therapy should be facilitated.

Children's Oncology Group's 2013 blueprint for research: radiation oncology

Radiation therapy (RT) is used to treat children with CNS tumors, solid tumors or Hodgkin lymphoma. Pediatric radiation oncologists have provided critical input into the development and implementation of concepts for clinical trials to further define the modality's role and test newer methods to reduce side effects or intensify therapy. The quality of pediatric oncology clinical trials that include radiation therapy is linked to the quality of guidelines. Radiation oncology is an adult medical specialty; thus, pediatric radiation oncologists are uniquely positioned to work with adult cancer investigators in the reorganized US National Cancer Institute Clinic Trials Network.

An Unusual Location of Extraosseous Ewing's Sarcoma

Ewing's sarcoma (ES) is the second most common malignant bone tumor in children and young adults. ES also occurs as a primary soft tissue neoplasm without involvement of bone. We report the second case of extraosseous (EO) ES emerging from the omentum and a review of the relevant literature. EO ES should be included in the differential diagnosis of soft tissue neoplasms in the abdomen.

Ewing's sarcoma family of tumors in Finland during 1990-2009: a population-based study

BACKGROUND

Ewing's sarcoma family of tumors (ESFTs) are rare bone and soft tissue tumors characterized by specific genetic alterations. Our aim was to carry out a nationwide analysis of ESFT, to survey the treatments used and to report the five-year disease specific and event-free survival rates (EFS and DSS).

MATERIAL AND METHODS

The study data was gathered from the Finnish National Cancer Registry and all five University Hospitals and consisted of 76 bone and soft tissue ESFT patients diagnosed during 1990-2009. Their medical records were reviewed and data on their disease, treatments, complications and outcome were analyzed.

RESULTS

The five-year EFS and DSS of patients with localized disease at diagnosis (n = 57) were 70% and 60%, respectively. Factors contributing to DSS and EFS were the axial vs. peripheral site of primary tumor and adequate surgical resection of the primary tumor. DSS was also affected by patient's age at diagnosis and the treatment employed. The five-year DSS of patients with metastatic disease at diagnosis (n = 19) was 33% and both preoperative and high dose chemotherapy were associated with improved survival.

CONCLUSION

Population-based studies including both bone and soft tissue ESFTs are few. In this nationwide, population-based study on Finnish bone and soft tissue ESFT patients, we find their treatment successful and results comparable to those previously published. Absence of metastases, young age at diagnosis and a peripheral primary tumor site were associated with a better prognosis. It seems that surgical resection of the primary tumor should be performed whenever adequate resection margins can be achieved. The role of high dose chemotherapy merits further studies in this setting.

Pelvic Ewing sarcomas. Three-dimensional conformal vs. intensity-modulated radiotherapy

PURPOSE

The goal of the present work was to assess the potential advantage of intensity-modulated radiotherapy (IMRT) over three-dimensional conformal radiotherapy (3D-CRT) planning in pelvic Ewing's sarcoma.

PATIENTS AND METHODS

A total of 8 patients with Ewing sarcoma of the pelvis undergoing radiotherapy were analyzed. Plans for 3D-CRT and IMRT were calculated for each patient. Dose coverage of the planning target volume (PTV), conformity and homogeneity indices, as well as further parameters were evaluated.

RESULTS

The average dose coverage values for PTV were comparable in 3D-CRT and IMRT plans. Both techniques had a PTV coverage of V95 > 98 % in all patients. Whereas the IMRT plans achieved a higher conformity index compared to the 3D-CRT plans (conformity index 0.79 ± 0.12 vs. 0.54 ± 0.19, p = 0.012), the dose distribution across the target volumes was less homogeneous with IMRT planning than with 3D-CRT planning. This difference was statistically significant (homogeneity index 0.11 ± 0.03 vs. 0.07 ± 0.0, p = 0.035). For the bowel, Dmean and D1%, as well as V2 to V60 were reduced in IMRT plans. For the bladder and the rectum, there was no significant difference in Dmean. However, the percentages of volumes receiving at least doses of 30, 40, 45, and 50 Gy (V30 to V50) were lower for the rectum in IMRT plans. The volume of normal tissue receiving at least 2 Gy (V2) was significantly higher in IMRT plans compared with 3D-CRT, whereas at high dose levels (V30) it was significantly lower.

CONCLUSION

Compared to 3D-CRT, IMRT showed significantly better results regarding dose conformity (p = 0.012) and bowel sparing at dose levels above 30 Gy (p = 0.012). Thus, dose escalation in the radiotherapy of pelvic Ewing's sarcoma can be more easily achieved using IMRT.