Ewing's sarcoma. A retrospective study of histological and immunohistochemical factors and their relation to prognosis

Characteristics and oncologic outcomes of patients with Ewing sarcoma of the scapula

BACKGROUND AND OBJECTIVES

Ewing sarcoma is the second most common bone sarcoma of childhood. Ewing sarcomas of the scapula are rare, with little known about their characteristics and outcomes. In this study, we describe the demographic characteristics, tumor characteristics, and oncologic outcomes of patients with Ewing sarcoma of the scapula.

METHODS

This is a retrospective case series of thirty-four patients treated at three urban hospitals between 1993 and 2014 for Ewing sarcomas affecting the scapula. Their demographic data, tumor characteristics, and oncologic outcomes are reported and contrasted with data on Ewing sarcoma described in the literature.

RESULTS

Patients in our case series were 59% male. The average age at diagnosis was 16 years. 44% of patients had metastatic disease at presentation. 26% of patients had a tumor size >8 cm in largest dimension at diagnosis. 9 patients in our series had the t (11; 22) translocation present. Patients had a survival rate of 68% at five years. No patients had local recurrence of disease. Compared with findings reported in the literature concerning Ewing sarcoma affecting other locations, patients with Ewing sarcoma of the scapula were slightly older at time of diagnosis, had a lower percentage of tumors with size > 8 cm in largest dimension at presentation, and more commonly had metastatic disease at presentation. Patients in our cohort had a 5-year survival rate of 68%, which is higher than the rate of approximately 55% as reported in the general literature.

CONCLUSIONS

In this study, we describe a retrospective case series of thirty-four patients with Ewing sarcomas of the scapula. This is the largest case series to date of Ewing sarcoma affecting this location to our knowledge. These results will contribute to the understanding of the clinical profile and oncologic behavior of Ewing sarcomas affecting the scapula.

Comparison of Epidemiology, Clinical Features, and Outcomes of Patients with Reported Ewing Sarcoma and PNET over 40 Years Justifies Current WHO Classification and Treatment Approaches

Background

As of 2013, the WHO has classified peripheral primitive neuroectodermal tumors (PNETs) within the umbrella of Ewing sarcoma family of tumors (ESFTs) given their shared biology. Histologic features differ between PNET and Ewing sarcoma (ES), and potential clinical differences between PNET and ES have not been fully elucidated.

Methods

Through the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) database, we identified 3,575 patients identified with histologic diagnosis of ES or PNET from 1973 to 2014. We used Fisher's exact tests to compare patient and tumor characteristics between groups. Kaplan-Meier methods were used to estimate overall survival.

Results

Patients with ES were more likely to be male, ≤18 years old at diagnosis, white, and hispanic compared to patients with PNET (p=0.016 for sex; p < 0.001 for all other variables). Patients with PNET were more likely to have soft tissue primary tumors (p < 0.001), and among those with bone tumors, a lower rate of axial or pelvic tumors (p < 0.001). Patients with PNET had significantly worse 5-year survival compared to ES patients, though the absolute difference was small (51.3% versus 55.5%; p < 0.001). Survival of patients with PNET diagnosed in the 1990s or later more closely approximated patients with ES, while patients with PNET diagnosed in the 1980's and earlier had inferior outcomes.

Conclusions

Despite shared underlying biology, patients with PNET and ES show differences in clinical presentation and overall survival, with the latter differences largely mitigated in more recent decades.

Retrospective Analysis of Ploidy in Primary Osseous and Extraosseous Ewing Family Tumors in Children

Aims

To restrospectively study the DNA content in a series of childhood Ewing Family Tumors (EFT), and to investigate its prognostic value.

Methods

The study was performed on a series of 27 EFTs (osseous Ewing's sarcoma, 18 cases; extraos-sous Ewing's sarcoma, 2; peripheral neuroepithelioma, 4; Askin Rosai tumors, 3). Ploidy was investigated using both flow cytometry (FCM) and image cytometry (ICM) on tumor cell suspensions from formalin-fixed paraffin-embedded specimens or fresh frozen tissue obtained from the primary tumor at diagnosis.

Results

Ploidy was evaluable by FCM in all cases, and by ICM in 23/27. When fresh frozen tissue and paraffin-embedded samples from the same tumor were available for analysis, they yielded equal results. The rate of agreement between FCM and ICM was 82%. The majority of cases were diploid, and in the present series aneuploidy seemed to be associated with a poor outcome.

Conclusions

These results suggest that aneuploidy could be an indicator of a bad prognosis in EFT; however, the small number of cases precludes any conclusion of statistical value. Larger restrospective studies on ploidy using archival material could be performed and their reliability is supported by the concordance of results from fresh and formalin-fixed tissue.

Gene expression profiling of peripheral blood cells: new insights into Ewing sarcoma biology and clinical applications

Ewing sarcoma (ES) is a group of highly aggressive small round cell tumors of bone or soft tissue with high metastatic potential and low cure rate. ES tumors are associated with a rapid osteolysis and necrosis. The currently accepted clinical prognostic parameters do not accurately predict survival of high-risk patients. Moreover, neither the subtype of EWS-FLI1/ERG in the tumor, nor the detection of fusion transcripts in the peripheral blood (PB) samples, has prognostic value in ES patients. We evaluated the prevalence of circulating tumor cells (CTCs) in 34 adult ES patients. Since CTCs were confirmed in only small subset of patients, we further explored the expression profiles of PB leukocytes using a panel of genes associated with immune system status and increased tumor invasiveness. Moreover, we analyzed the alterations of the routine blood tests in the examined cohort of patients and correlated our findings with the clinical outcome. A uniform decrease in ZAP70 expression in PB cells among all ES patients, as compared to healthy individuals, was observed. Monocytosis and the abnormal expression of CDH2 and CDT2 genes in the PB cells significantly correlated with poor prognosis in ES patients. Our study supports the previously proposed hypothesis of systemic nature of ES. Based on the PB cell expression profiles, we propose a mechanism by which immune system may be involved in intensification of osteoclastogenesis and disease progression in ES patients. Moreover, we demonstrate the prognostic value of molecular PB testing at the time of routine histopathological diagnosis.

Ewing sarcoma/peripheral primitive neuroectodermal tumor and related tumors

Ewing sarcoma/peripheral primitive neuroectodermal tumor (EWS/pPNET) and other tumors with EWS gene rearrangements encompass a malignant and intermediate neoplasm with a broad anatomic distribution and a wide age range but a predilection for soft tissue in children, adolescents, and young adults. The overlapping histologic, immunohistochemical and cytogenetic and molecular genetic features create diagnostic challenges despite significant clinical and prognostic differences. Ewing sarcoma is the 3rd most common sarcoma in children and adolescents, and desmoplastic small round cell tumor is a rare neoplasm that occurs more often in older children, adolescents, and young adults. Pathologic examination is complemented by immunohistochemistry, cytogenetics, and molecular genetics. This article reviews the clinicopathologic features of EWS/pPNET and desmoplastic small round cell tumor in the spectrum of tumors with EWS gene rearrangements. Other tumors with different histopathologic features and an EWS gene rearrangement are discussed elsewhere in this volume.

Treatment effects in pediatric soft tissue and bone tumors: practical considerations for the pathologist

Dramatic improvements in survival for children with cancer have led to increased numbers of posttreatment pathologic specimens, particularly in bone and soft tissue sarcomas. Current therapeutic protocols in North America require specific pathologic classification and stratify patients based on clinical, biologic, and pathologic features. For osteosarcoma, the pathologic response to therapy predicts prognosis and modifies the treatment regimen. Ongoing studies aim to assess the response to therapy and outcome in other types of soft tissue and bone tumors. The pathologic evaluation of pretreatment and posttreatment specimens is critical for therapeutic decisions and prognostic assessment. A standardized approach to posttherapy pathologic specimens, with attention to appropriate use of ancillary tests, and assessment of clinical and biologic significance of therapy-induced pathologic changes has significance for patient management and treatment protocols.

A systematic review of molecular and biological markers in tumours of the Ewing's sarcoma family

The aims of this study were to perform the first systematic review of molecular and biological tumour markers in tumours of the Ewing's sarcoma family (ESFT), and evaluate the current evidence for their clinical use. A well-defined, reproducible search strategy was used to identify the relevant literature from 1966 to February 2000. Papers were independently assessed for tumour markers used in the screening, diagnosis, prognosis or monitoring of patients with ESFT. Eighty-four papers studying the use of 70 different tumour markers in ESFT's were identified. Low-quality, inconsistent reporting limited meta-analysis to that of prognostic data for 28 markers. Patients with tumours lacking S-100 protein expression have a better overall survival (OS) (hazard ratio (HR)=0.41, 95% confidence interval (CI) 0.19, 0.89) than those with expression; patients with high levels of serum LDH had a worse OS and disease-free survival (DFS) (OS: HR=2.92, CI 2.16, 3.94, DFS: HR=3.38, 95% CI 2.28, 4.99); patients with localised disease and tumours expressing type 1 EWS-FLI1 fusion transcripts had an improved DFS compared with those with other fusion transcript types (HR=0.17, 95% CI 0.079, 0.37). The knowledge base formed should facilitate more informative future research. Improved statistical reporting and large, multicentre prospective studies are advocated.

Neoadjuvant chemotherapy for peripheral malignant neuroectodermal tumor of bone: recent experience at the istituto rizzoli

PURPOSE

The results achieved in 44 patients with nonmetastatic peripheral neuroectodermal tumor (PNET) of bone treated with neoadjuvant chemotherapy are reported.

PATIENTS AND METHODS

A six-drug regimen of chemotherapy (vincristine, doxorubicin, dactinomycin, cyclophosphamide, ifosfamide, and etoposide) was administered to all patients. Local treatment consisted of surgery in 20 patients, surgery followed by radiotherapy in 13, and radiotherapy only in 11.

RESULTS

At a mean follow-up of 4.5 years (range, 2 to 7 years), 23 patients (52%) remain event-free, 20 have relapsed (45%), and one has died of chemotherapy-related toxicity. The 5-year event-free survival and overall survival were 54.2% and 62.7%, respectively. To assess the prognostic significance of neural differentiation in the family of Ewing's sarcoma, these results have been compared with the outcomes of 138 concomitant patients with typical Ewing's sarcoma (TES) who were treated according to the same protocol. Of these, 103 (75%) remained continuously event-free, 34 (24%) relapsed, and one died of chemotherapy-related toxicity. It follows that PNET patients treated with this chemotherapy regimen have a significantly worse prognosis than typical ES patients (5-year event-free survival, 54.2% v 70.6%, P <.012; 5-year overall survival, 62.7% v 78.3%, P <.002).

CONCLUSION

The authors conclude that studies into new adjuvant therapy for Ewing's sarcoma modulated according to risk of relapse should also consider neural differentiation as a risk factor.

Neuroectodermal differentiation in Ewing's sarcoma family of tumors does not predict tumor behavior

The observation that neuroectodermal differentiation imparts a worse prognosis to the Ewing family of tumors has been suggested by some studies and refuted by others. To assess whether the diagnosis of Ewing's sarcoma versus peripheral primitive neuroectodermal tumor (PNET) affects prognosis, we analyzed tumors from 63 analogously treated pediatric and young adult patients from the National Cancer Institute and St Jude Children's Research Hospital and retrospectively compared the results with clinical outcomes. The tumors were assessed using standard light microscopy and immunohistochemical stains for neuron-specific enolase, CD57, S100 protein, neurofilament protein, and synaptophysin with or without antigen retrieval. Ultrastructural evaluation was also performed in 39 tumors. Classification was performed using Kiel criteria as well as a modified classification. Kaplan-Meier analyses, with Mantel-Haenzel evaluation of the significance of the differences, were performed separately for localized or metastatic tumors. Using the Kiel classification on a subset of 60 cases, 39 tumors qualified as PNET and 21 as Ewing's sarcoma. Using the modified classification on a subset of 61 cases, 14 were classified as PNET, 21 as atypical Ewing's sarcoma, and 26 as Ewing's sarcoma. The addition of electron microscopy to the diagnostic armamentarium significantly increased the likelihood of identifying PNET. No significant differences in event-free or overall survival were seen using either the modified or Kiel classification, regardless of the ancillary diagnostic techniques employed. In this exploratory analysis, neuroectodermal differentiation did not play a role in clinical outcome. Confirmation of this finding will require a larger, separate study of similarly treated patients, and it may not apply to older patients.

Appraisal of the comparative utility of immunohistochemistry and electron microscopy in the diagnosis of childhood round cell tumors

To provide an objective assessment of the comparative utility of fluorescence- and peroxidase-based immunohistochemistry and electron microscopy, an observer blinded study was conducted under realistic study conditions utilizing a large sampling of poorly differentiated pediatric round cell tumors. Working independently, using a single ancillary technique of particular expertise, each of three investigators attempted to render a specific diagnosis with regard to 50 diagnostically challenging tumors. The results were compared against the subsequent "file diagnosis" established by consensus with all relevant information made available. A grading scheme was applied wherein points were awarded based on the accuracy and confidence of diagnosis. A comparative efficiency rating, expressed as a percentage, was formulated by dividing the number of points awarded each technique by the total number of points theoretically available. Electron microscopy proved superior overall, with an efficiency rating of 89%. Immunoperoxidase and immunofluorescence studies yielded efficiency ratings of 71 and 61%, respectively. Used in combination, the techniques achieved an efficiency rating of 95%. Application of these ancillary techniques resulted in a revision of the provisional diagnosis in 11 of 50 cases, and left only two cases without a firm specific diagnosis.

Small cell osteosarcoma of the soft tissue

The lesion we described is an osteoid producing mitotically active spindle cell soft tissue neoplasm, which has light and ultrastructural features of an osteosarcoma. By immunohistochemistry it marks with p30/32MIC2-directed antibodies but fails to react with antibodies associated with other soft tissue neoplasms. The precise histogenesis of the lesion is unknown, but failure to elicit a periosteal reaction makes the periosteum less likely to be the primary tissue of origin. The failure to demonstrate any radiologic or histologic evidence of involvement of the underlying bone leaves the soft tissue as the most reasonable site of origin, although the parosteal region cannot be completely excluded.

Is neuro-ectodermal differentiation of Ewing's sarcoma of bone associated with an unfavourable prognosis?

Among Ewing's sarcoma (ES) of bone and related entities are tumours with neuro-ectodermal features that could represent a biologically distinct type. In order to assess the prognostic significance of the various forms of ES, a retrospective joint study involving three cancer centres in Europe and the U.S.A. was initiated. The material from 315 primary ES was reviewed by a panel of five pathologists and classified as typical ES (220 cases), atypical ES (48 cases) or ES with neuro-ectodermal features (47 cases). Prognostic factor analysis on treatment failure-free survival was performed using the Cox model. It included histopathological classification, initial patient characteristics, clinical presentation and treatment type. After multivariate analysis, in addition to treatment type (P < 0.001), metastases (P = 0.003) and proximal tumour location (P = 0.006), two histopathological parameters correlated with poor treatment failure-free survival, the presence of filigree pattern (P = 0.044) and dark cells (P = 0.043). We conclude that ES with neuro-ectodermal features does not appear to have a different outcome to the other subtypes.

Extraskeletal Ewing's sarcoma of the parotid region: a case report with the detection of the tumour's immunophenotypical characteristics

A case report of a malignant small round cell tumour of the parotid region, with features of extraskeletal Ewing's sarcoma is presented. Besides its rare location in the soft tissues of the parotid area, the tumour expressed focal NSE and desmin immunoreactivity, indicative of multidirectional differentiation.

Primitive neuroectodermal tumors of bone and soft tissue: histological subclassification and clinicopathologic correlations

Recent reports of Ewing's sarcoma (EW) and extraskeletal Ewing's sarcoma (EEW) support the hypothesis that these tumors are neuroectodermal in origin. Primitive neuroectodermal tumors (PNET) of bone (32 cases) and soft tissue (25 cases) including those previously categorized as EW in 27 cases and EEW in 15 cases were carefully studied histologically, immunocytochemically and morphometrically, focusing on tumor cell differentiation. This study attempts to subclassify these tumors on the basis of the size of tumor cells and nuclei, their variations (uniformity or diversity), arrangement of tumor cells (rosette or non-rosette), focal differentiation to larger ganglion-like cells, and staining intensity for neural markers. All tumors were histologically subclassified as small, medium or large cell types, three basic subtypes (rosette type, abortive rosette type, non-rosette type) and four complementary subtypes (fibrillary type, non-fibrillary type, angiomatoid type, ganglion cell type). Classic EW or EEW is consistent with small or medium, non-rosette, non-fibrillary type tumors, previously described large cell EW with large, non-rosette, fibrillary or non-fibrillary type tumors, and classic neuroectodermal tumor with small or medium, rosette, fibrillary type tumors, according to the present subclassification. Clinicopathologic correlations with the different subtypes are discussed. Long-term survival, more than 5 years, was seen in patients with small cell type, and those younger than 14 years of age.

Ewing sarcoma of bone in infants and toddlers. A clinicopathologic report from the Intergroup Ewing's Study

BACKGROUND

Nineteen patients with Ewing sarcoma of bone, each younger than 3 years of age at the time of initial presentation, are reported. These children represent an unusually young age group for documented Ewing sarcoma and represent 2.6% of all patients registered in the Intergroup Ewing's Sarcoma Study (IESS).

METHODS

The diagnosis was made on combined histologic, clinical, and radiographic grounds and was supported by immunohistochemistry in nine patients and electron microscopic study in eight patients. Immunohistochemical studies showed no staining against neuro-specific enolase, chromogranin, or S-100 in any patients, and in only one in nine patients were results of such studies focally positive against Leu-7.

RESULTS

The most marked clinical variation between this group of infants and the general IESS patient population was a striking predominance of female patients in the younger age group (P < 0.001). There was a trend toward more rib, pelvis, and proximal long bone tumors in the infants and toddlers. The overall survival rate of the infants was 56%, almost identical to the survival rates of the older children. All of the infants who died of disease did so within 4 years. Extended follow-up as long as 9.9 years has found no late deaths attributable to tumor. The most significant late complications of therapy included cardiotoxicity with cerebral embolization from the heart and a short lower limb secondary to radiation therapy.

CONCLUSIONS

Ewing sarcoma must be considered in the differential diagnosis of small cell, round cell, and blue cell tumors in bone, even in infants and toddlers.

The immunophenotype of Ewing's sarcoma. An immunohistochemical analysis

Since 1963, 53 cases of Ewing's sarcoma have been diagnosed at the N. Goormaghtigh Institute of Pathological Anatomy. All tumours were classified according to their growth pattern as described by Kissane: diffuse, lobular or organoid, the latter with pseudorosettes, or belonging to the fillagree type. In 45 cases, an immunohistochemical examination was carried out on routinely processed material in order to determine the immunophenotype of the tumours and to get more information on the histogenesis of the tumours. Antibodies against cytokeratin, desmin, vimentin, neurofilaments, neuron-specific enolase, Leu7, synaptophysin, chromogranin, the muscle-specific actin, the Von Willebrand factor and the common leucocyte antigen were used in a biotin-streptavidin procedure. The presence of neural markers such as neuron-specific enolase, synaptophysin and Leu7 was proved in the majority of the cases. The expression of the three markers was absent in only two cases. Neurofilaments were demonstrated to be present in 5 of the 6 cases for which fresh material was available. The results of this study point towards a possible neuroectodermal origin of Ewing's sarcoma. This is in agreement with the results of cell culture experiments and of cytogenetic studies.

Malignant peripheral neuroectodermal tumor and its necessary distinction from Ewing's sarcoma. A report from the Kiel Pediatric Tumor Registry

A new classification scheme is proposed for the differential diagnosis of Ewing's sarcoma and malignant peripheral neuroectodermal tumor (MPNT) based on conventional light microscopic and immunohistochemical findings. The presence of Homer-Wright rosettes and/or the expression of at least two neural markers is diagnostic of MPNT Ewing's sarcoma. Ewing's sarcoma was diagnosed in cases lacking Homer-Wright rosettes and expressing no neural marker or only one in immunohistochemistry. Using this "new" approach considerable differences were found between both tumor types. Although most MPNT were located in the thoracopulmonary region, Ewing's sarcoma was located predominantly in the pelvis and extremities. The mean age of MPNT patients was greater than that of Ewing's sarcoma patients. Most importantly, however, was a statistically significant difference in prognosis: disease-free survival in Ewing's sarcoma patients at 7.5 years follow-up was 60% compared with 45% MPNT patients (P = 0.026). The detection of HNK-1 in MPNT indicated a more aggressive biologic behavior, and the expression of protein S-100 appeared to be correlated with a more favorable clinical course.

Prognostic value of histopathology in Ewing's sarcoma. Long-term follow-up of distal extremity primary tumors

The pathologic material from 56 patients diagnosed initially as Ewing's sarcoma of the distal extremity and treated on National Cancer Institute protocols between 1968 and 1984 was reviewed and correlated with clinical outcome. Histologically, the tumors were categorized, based on recent pathologic criteria, into three diagnostic groups: (1) typical Ewing's sarcoma, (2) atypical Ewing's sarcoma, and (3) other (predominantly peripheral neuroepithelioma [PN]). Thirty-two patients (57%) had typical Ewing's, 13 (23%) were atypical, and 11 (20%) were in the "other" diagnostic category (seven [13%] PN, two primitive rhabdomyosarcoma, one primitive sarcoma of bone, and one synovial cell sarcoma). No cases of metastatic neuroblastoma, osteosarcoma, or lymphoma were found. Forty-five patients had localized disease at diagnosis; 11 had metastases. Patients with typical Ewing's sarcoma were less likely to have metastatic disease at the time of diagnosis. Only two of 32 patients with typical Ewing's sarcoma had metastases compared with nine of 24 patients in the two other groups. The pattern of relapse was also different in these other groups compared with typical Ewing's patients; five patients developed lymph node metastases and two patients developed brain metastases. Although the presence of metastatic disease at diagnosis was a strong negative prognostic factor, our histologic grouping was independently prognostic of clinical outcome in patients with localized disease. Patients with typical osseous Ewing's sarcoma had an improved overall survival (P2 = 0.03) and patients with other tumors (neither typical nor atypical Ewing's sarcoma) had a poorer disease-free survival (P2 = 0.02). Since no generally accepted histopathologic prognostic criteria exist for Ewing's sarcoma, the potential value of our proposed classification should be evaluated in a larger retrospective and a prospective study.

Neural differentiation in small round cell tumors of bone and soft tissue with the translocation t(11;22)(q24;q12): an immunohistochemical study of 11 cases

Clinical, cytogenetic, histopathologic, and immunohistochemical data were obtained in a series of 11 small round cell tumors (SRCT) of bone and soft tissue with the translocation t(11;22) (q24;q12). Ten cases were primary in bone, and one was of extraskeletal origin. According to conventional histopathologic criteria, 10 cases were Ewing's sarcomas (ES) and one was a peripheral neuroectodermal tumor (PNET). Besides the t(11;22), six cases had additional chromosomal aberrations, including trisomy 7 and partial trisomy for the long arm of chromosome 1, which have both been described as nonspecific secondary abnormalities often associated with tumor progression. The tumors were screened for neural differentiation with an antibody panel consisting of neuron-specific enolase, S100 protein, Leu-7, chromogranin, synaptophysin, and neurofilament. Three cases of ES were positive for S100 protein. The PNET and one case of ES were positive for neuron-specific enolase. All of the remaining immunohistochemical stains were negative. Hence, five of 11 SRCT of bone or soft tissue with the t(11;22) showed morphologic and/or immunohistochemical evidence of neural differentiation. In this limited series of cases, no cytogenetic or prognostic differences could be demonstrated between cases with and without a neural phenotype. Our results support the hypothesis that SRCT of bone of soft tissue with the t(11;22) form a single biologic entity displaying varying degrees of neuroectodermal differentiation. The clinical significance of additional cytogenetic abnormalities and of morphologic or immunohistochemical evidence of neural differentiation in this group of tumors needs to be further studied.

Isolated CNS involvement in Ewing's sarcoma

Ewing's sarcoma, an uncommon malignant neoplasm of bone, represents about 10% of all the malignant primary bone tumors. The assumption that subclinical metastases are already present in patients with apparently localized tumor indicates the need for systemic therapy as an integral part of primary treatment. The usual sites of metastases are the lungs and skeletal system. Central nervous system (CNS) involvement is rare and is usually seen only in disseminated and fairly advanced disease. We report two patients in whom, after aggressive adjuvant chemotherapy, disease developed in the CNS without local recurrence. In one patient, meningeal involvement with malignant cells was identifiable in the cerebrospinal fluid; in the second patient, who presented with a space-occupying lesion, a diagnosis of arachnoid involvement was made histologically.