Intraoperative radiation therapy for pediatric sarcomas and other solid tumors

PURPOSE

To evaluate local failure (LF) and toxicity after intraoperative radiation therapy (IORT) in pediatric solid tumors (ST).

METHODS

A single-institution retrospective study of 96 pediatric patients (108 applications) with ST treated from 1995 to 2022 with IORT. LF was calculated via cumulative incidence function and overall survival (OS) by Kaplan-Meier method, both from the day of surgery.

RESULTS

Median age at time of IORT was 8 years (range: 0.8-20.9 years). Median follow-up for all patients and surviving patients was 16 months and 3 years, respectively. The most common histologies included rhabdomyosarcoma (n = 42), Ewing sarcoma (n = 10), and Wilms tumor (n = 9). Most (95%) received chemotherapy, 37% had prior external beam radiation therapy to the site of IORT, and 46% had a prior surgery for tumor resection. About half (54%) were treated with upfront IORT to the primary tumor due to difficult circumstances such as very young age or challenging anatomy. The median IORT dose was 12 Gy (range: 4-18 Gy), and median area treated was 24 cm2 (range: 2-198 cm2). The cumulative incidence of LF was 17% at 2 years and 23% at 5 years. Toxicity from IORT was reasonable, with postoperative complications likely related to IORT seen in 15 (16%) patients.

CONCLUSION

Our study represents the largest and most recent analysis of efficacy and safety of IORT in pediatric patients with ST. Less than one quarter of all patients failed locally with acceptable toxicities. Overall, IORT is an effective and safe technique to achieve local control in patients with challenging circumstances.

A Single-center Experience of Radiotherapy in Pediatric Ewing Sarcoma/Primitive Neuroectodermal Tumor of the Chest Wall

AIM

To evaluate the treatment results, prognostic parameters, and treatment-related toxicity in patients with Ewing sarcoma (ES)/primitive neuroectodermal tumor (PNET) of the chest wall who underwent surgery, chemotherapy, and radiotherapy (RT) in a tertiary referral center.

METHODS

The data of 24 patients under 18 years of age with a histologic diagnosis of ES/PNET in the chest wall that received RT in our department between February 2003 and July 2020 were retrospectively evaluated. RT was applied to the primary site±whole involved chest wall and to the whole lung in patients with lung metastasis.

RESULTS

The median age was 8.5 years (range: 1.5 to 17 y), 15 (63%) patients were female and 9 were male (37%). The tumor localization was extrathoracic in 18 (75%) and intrathoracic in 6 (25%) patients. Mediastinal lymph node and distant metastasis (DM) was present in 5 (21%) and 4 (16%) cases at diagnosis, respectively. The median follow-up after RT was 47 months (range: 11 to 162 mo). The 2-year and 5-year overall survival, event-free survival, local recurrence-free survival, and pleural recurrence-free survival were 83% and 48%, 48% and 42%, 74% and 48%, and 61% and 52%, respectively. The overall local control rate was 83% and the pleural control rate was 67%. RT was well tolerated, with 1 case of grade 3 acute dermatitis and 1 case of grade 3 subacute radiation pneumonitis. Late toxicity was observed in 3 (13%) cases.

CONCLUSION

Long-term survival can be achieved with extended-field RT even in patients with ES/PNET of the chest wall with DM. The low toxicity rates allow us to draw the conclusion that RT with modern techniques is an effective and safe treatment modality for these patients.

[Analysis of 41 cases of non-metastatic Ewing's sarcoma in children]

OBJECTIVES

To summarize the clinical characteristics, treatment outcomes, and prognostic factors of children with non-metastatic Ewing's sarcoma (ES).

METHODS

A retrospective analysis was conducted on the clinical data of 41 children with non-metastatic ES diagnosed and treated at the Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine from January 2010 to December 2018. All patients underwent chemotherapy based on the RMS-2009 protocol of the center, and local treatment such as surgery and/or radiotherapy was performed according to risk grouping. The Kaplan-Meier method was used to calculate the overall survival (OS) and event-free survival (EFS) rates. Univariate prognostic analysis was performed using the log-rank test, and multivariate analysis was conducted with Cox regression.

RESULTS

Of the 41 children, 21 were male and 20 were female. The median age at diagnosis was 7.7 years (range: 1.2-14.6 years). The median follow-up time for patients with event-free survival was 68.1 months (range: 8.1-151.7 months). As of the last follow-up, 33 patients were in complete remission, and the overall 5-year EFS and OS rates were (78±6)% and (82±6)%, respectively. Univariate analysis by the log-rank test showed that a tumor diameter ≥8 cm, time from diagnosis to start of local treatment ≥16 weeks, and incomplete surgical resection were associated with poor prognosis (P<0.05). Multivariate Cox regression analysis indicated that incomplete surgical resection (HR=8.381, 95%CI: 1.681-41.801, P=0.010) was an independent risk factor for poor prognosis in children with ES. Secondary tumors occurred in 2 cases.

CONCLUSIONS

A comprehensive treatment strategy incorporating chemotherapy, surgery, and radiotherapy can improve the prognosis of children with ES. Poor prognosis is associated with an initial tumor diameter ≥8 cm, while complete surgical resection and early initiation of local treatment can improve outcomes.

Disparities in incidence and survival for patients with Ewing sarcoma in Florida

BACKGROUND

Ewing sarcoma (ES) is a malignant bone tumor most commonly affecting non-Hispanic White (NHW) adolescent males, though recognition among Hispanic individuals is rising. Prior population-based studies in the United States (US), utilizing Surveillance, Epidemiology, and End Results (SEER) have shown higher all-cause mortality among White Hispanics, Blacks, and those of low socioeconomic status (SES). Florida is not part of SEER but is home to unique Hispanic populations including Cubans, Puerto Ricans, South Americans that contrasts with the Mexican Hispanic majority in other US states. This study aimed to assess racial/ethnic disparities on incidence and survival outcomes among this diverse Florida patient population.

METHODOLOGY

Our study examined all patients diagnosed with osseous ES (2005-2018) in Florida (n = 411) based on the state's population-based cancer registry dataset. Florida Age-adjusted Incidence Rates (AAIRs) were computed by sex and race-ethnicity and compared to the equivalent populations in SEER. Cause-specific survival disparities among Florida patients were examined using Kaplan-Meier analysis. Univariable and multivariable analyses using Cox regression were performed for race/ethnicity, with adjustment for age, sex, year of diagnosis, site of disease, staging, SES, and insurance type.

RESULTS

There was a significantly higher incidence of osseous ES in Florida Hispanic males (AAIR 2.6/1,000,000); (95% CI: 2.0-3.2 per 1,000,000; n = 84) compared to the SEER Hispanic males (AAIR 1.2/1,000,000;1.1-1.4 per 1,000,000; n = 382). Older age, distant metastasis, lack of chemotherapy or surgical resection were statistically significant determinants of poor survival while SES, insurance status and race-ethnicity were not. However, among nonmetastatic ES, Florida Hispanics had an increased risk of death compared to Florida NHW (adjusted Hazard Ratio 2.32; 95%CI: 1.20-4.46; p = 0.012).

CONCLUSIONS

Florida Hispanic males have a higher-than-expected incidence of osseous ES compared to the US. Hispanics of both sexes show remarkably worse survival for nonmetastatic disease compared to NHW. This disparity is likely multifactorial and requires further in-depth studies.

TRIM8 modulates the EWS/FLI oncoprotein to promote survival in Ewing sarcoma

Fusion-transcription factors (fusion-TFs) represent a class of driver oncoproteins that are difficult to therapeutically target. Recently, protein degradation has emerged as a strategy to target these challenging oncoproteins. The mechanisms that regulate fusion-TF stability, however, are generally unknown. Using CRISPR-Cas9 screening, we discovered tripartite motif-containing 8 (TRIM8) as an E3 ubiquitin ligase that ubiquitinates and degrades EWS/FLI, a driver fusion-TF in Ewing sarcoma. Moreover, we identified TRIM8 as a selective dependency in Ewing sarcoma compared with >700 other cancer cell lines. Mechanistically, TRIM8 knockout led to an increase in EWS/FLI protein levels that was not tolerated. EWS/FLI acts as a neomorphic substrate for TRIM8, defining the selective nature of the dependency. Our results demonstrate that fusion-TF protein stability is tightly regulated and highlight fusion oncoprotein-specific regulators as selective therapeutic targets. This study provides a tractable strategy to therapeutically exploit oncogene overdose in Ewing sarcoma and potentially other fusion-TF-driven cancers.

STAG2 mutations alter CTCF-anchored loop extrusion, reduce cis-regulatory interactions and EWSR1-FLI1 activity in Ewing sarcoma

STAG2, a cohesin family gene, is among the most recurrently mutated genes in cancer. STAG2 loss of function (LOF) is associated with aggressive behavior in Ewing sarcoma, a childhood cancer driven by aberrant transcription induced by the EWSR1-FLI1 fusion oncogene. Here, using isogenic Ewing cells, we show that, while STAG2 LOF profoundly changes the transcriptome, it does not significantly impact EWSR1-FLI1, CTCF/cohesin, or acetylated H3K27 DNA binding patterns. In contrast, it strongly alters the anchored dynamic loop extrusion process at boundary CTCF sites and dramatically decreases promoter-enhancer interactions, particularly affecting the expression of genes regulated by EWSR1-FLI1 at GGAA microsatellite neo-enhancers. Down-modulation of cis-mediated EWSR1-FLI1 activity, observed in STAG2-LOF conditions, is associated with enhanced migration and invasion properties of Ewing cells previously observed in EWSR1-FLI1low cells. Our study illuminates a process whereby STAG2-LOF fine-tunes the activity of an oncogenic transcription factor through altered CTCF-anchored loop extrusion and cis-mediated enhancer mechanisms.

Ubiquitin-Specific Protease 6 Functions as a Tumor Suppressor in Ewing Sarcoma through Immune Activation

Ewing sarcoma is the second most common pediatric bone cancer, with a 5-year survival rate for metastatic disease of only 20%. Recent work indicates that survival is strongly correlated with high levels of tumor-infiltrating lymphocytes (TIL), whose abundance is associated with IFN-inducible chemokines CXCL10 and CCL5. However, the tumor-intrinsic factors that drive chemokine production and TIL recruitment have not been fully elucidated. We previously showed that ubiquitin-specific protease 6 (USP6) directly deubiquitinates and stabilizes Jak1, thereby inducing an IFN signature in Ewing sarcoma cells. Here, we show that this gene set comprises chemokines associated with immunostimulatory, antitumorigenic functions, including CXCL10 and CCL5. USP6 synergistically enhanced chemokine production in response to exogenous IFN by inducing surface upregulation of IFNAR1 and IFNGR1. USP6-expressing Ewing sarcoma cells stimulated migration of primary human monocytes and T lymphocytes and triggered activation of natural killer (NK) cells in vitro. USP6 inhibited Ewing sarcoma xenograft growth in nude but not NSG mice and was accompanied by increased intratumoral chemokine production and infiltration and activation of NK cells, dendritic cells, and macrophages, consistent with a requirement for innate immune cells in mediating the antitumorigenic effects of USP6. High USP6 expression in patients with Ewing sarcoma was associated with chemokine production, immune infiltration, and improved survival. This work reveals a previously unrecognized tumor-suppressive function for USP6, which engenders an immunostimulatory microenvironment through pleiotropic effects on multiple immune lineages. This further raises the possibility that USP6 activity may be harnessed to create a "hot" tumor microenvironment in immunotherapy. SIGNIFICANCE: This study reveals a novel tumor-suppressive function for USP6 by inducing an immunostimulatory microenvironment, suggesting that USP6 activity may be exploited to enhance immunotherapy regimens.

Irinotecan and temozolomide chemotherapy in paediatric and adult populations with relapsed Ewing Sarcoma

BACKGROUND

Irinotecan and temozolomide (IT) is a widely used regimen for relapsed Ewing sarcoma (ES), although studies are largely limited to paediatric populations.

METHODS

We retrospectively reviewed paediatric (< 18 years) and adult patients (≥ 18 years) treated with salvage IT at two institutions. Haematologic toxicities were graded according to common terminology criteria of adverse events. Survival was estimated by the Kaplan-Meier method and compared by the Log Rank test.

RESULTS

Fifty-three patients were treated with IT from Jan, 2010 to Dec, 2018 (n = 16 paediatric; n = 37 adult). IT was given as second-line (n = 34; 64%) or ≥ third-line (n = 19; 36%). There was no difference in ≥ grade 3/4 haematologic toxicity between paediatrics and adults (31% vs. 35% respectively; p = 0.76). The frequency of diarrhoea of any grade was similar (38% in each group). Of 43 patients assessable for response, 12 (28%) had objective response (1 CR, 11 PR), 12 (28%) stable disease and 19 (44%) disease progression. Objective response rate did not differ between the two groups (36% in paediatrics vs. 25% in adults; p = 0.47). Median PFS was superior in paediatrics vs. adults (7.4 vs. 2.2 months, p = 0.039).

CONCLUSION

Irinotecan and temozolomide (IT) chemotherapy has activity for relapsed ES, with favourable toxicity and equally observed objective responses in the paediatric and adult populations. The observed superior PFS for the paediatric cohort requires further confirmation in future studies.

Primary chest wall sarcoma; a single institution experience of 3 years

INTRODUCTION

Primary chest wall sarcoma is a rare entity. It can be classified based on its origin, as bone sarcomas or soft tissue sarcomas. Various prognostic factors have been studied in different case series like age, sex, tumor histology, grade, resection margin status, adjuvant treatment, and others. The present study aimed to analyze common histological types, their management by resection and reconstruction and prognosis, in cases presenting at a regional cancer center in western India.

MATERIAL AND METHOD

This was an observational study from a prospectively maintained database. 57 patients with chest wall sarcoma treated with curative intent between January 2016 till January 2019 with a minimum follow-up of 3 months were included in the study. The goals of surgical treatment were to obtain a wide resection margin of 3-4 cm, preserve the function of the chest wall and provide stability and rigidity to protect intrathoracic organs.

RESULTS

The median follow-up of the present patient's cohort was for 20.2 months. Overall two-year survival was 74.7%. Two-year OS and DFS of bone sarcoma were 62.3% and 35% and soft tissue sarcomas were 91% and 71.3%. Ewing's sarcoma had the worst two-year overall survival of 50.6% and chondrosarcoma and fibromatosis had 100% two-year overall survival.

CONCLUSION

Chest wall sarcoma forms a heterogeneous group of tumors. In the present study, Ewing's sarcoma was the most common histology with the worst survival, since they presented in advanced stages. Management should be multidisciplinary and surgical resection should be aggressive to achieve an R0 resection. Reconstruction of chest wall should aim to provide structural and functional stability with minimal morbidity. Frozen section assessment should be utilized whenever in doubt.

CCT6A, a novel prognostic biomarker for Ewing sarcoma

BACKGROUND

Ewing sarcoma (ES), the second most prevalent bone malignant tumor has no widely known prognostic biomarker. Earlier studies have suggested that chaperonin containing TCP1 complex 6A (CCT6A), which encodes a molecular protein chaperone, is involved in the pathogenesis of many cancers. However, there are no known reports providing clear evidence of its role in ES pathogenesis.

METHODS

We performed a bioinformatic analysis of 32 ES specimens from the GSE17618 dataset concentrating on the differences in gene expression, OS, event-free survival (EFS) in the different subgroups. Immunohistochemical studies were also performed to identify the expression levels of selected genes in ES and immediate paracancerous tissues.

RESULTS

After 3 screenings, CCT6A was identified to be highly correlated with ES prognosis. Our survival analysis revealed a low overall survival (OS) for high CCT6A expression (P-value = .024). Our Cox regression analysis identified CCT6A expression, lEFS, and age were strongly associated with prognosis of ES. Our multivariate Cox regression analysis shows that CCT6A (P-value = .015), age (P-value = .026), and EFS (P-value = .002) were independent poor prognostic biomarkers. Our immunohistochemical analysis showed that the expression levels of CCT6A were significantly higher in ES tissues compared to the paracancerous tissues.

CONCLUSION

From the results of our study, we identified the expression levels of CCT6A to be strongly associated with prognosis of ES. Thus, the expression levels of the CCT6A gene could serve as a biomarker for the prediction of ES prognosis.

Establishing a novel prognostic tool for Ewing sarcoma patients: Surveillance, Epidemiology, and End Results database analysis

Patients diagnosed with Ewing sarcoma (ES) usually experience poor outcomes. Accurate prediction of ES patients' prognosis is essential to improve their survival. Given that ES is a relatively rare tumor with a low incidence, we aim at developing a prognostic nomogram of ES patients based on a large sample analysis.We used the Surveillance, Epidemiology, and End Results (SEER) database to screen eligible patients diagnosed ES of bone. This retrospective study presented the clinicopathological characteristics and prognosis of ES. We randomly assigned all ES patients to 2 sets (training set and validation set) with an equal number of patients. In order to identify independent factors of survival, we performed univariate and multivariate Cox analysis in the training set. Then, we constructed novel nomograms to predict survival of ES patients by integrating significant independent variables from the training set. The prognostic performance of constructed nomograms was examined using concordance index (C-index) and calibration curves in both training and validation set.We included a total of 988 eligible cases diagnosed ES of bone between 2000 and 2015. Age >18 years, distant metastasis, tumor size >10 cm, and no surgery were independent risk factors for poorer survival. Our survival prediction nomograms were established based on those 4 independent risk factors. Good calibration plots were achieved in internal and external validation. The internal validation C-indexes of the nomogram for overall survival (OS) and cancer-specific survival (CSS) were 0.733 and 0.737, respectively. Similar good results were also achieved in external validation setting.The established nomograms show good performance and allow for better evaluating the prognosis of ES patients and recommending appropriate instructions.

The clinical prognostic factors and treatment outcomes of adult patients with Ewing sarcoma

BACKGROUND

The data about treatment results of Ewing sarcoma in adult patients are limited. The aim of our study was to analyze prognostic factors and outcomes of therapy in this group of patients.

METHODS

Between 2000 and 2018, 180 patients at the age of > 18 years old diagnosed with Ewing sarcoma were treated in referral center according to multimodal protocols. In 50 patients (28%) treatment was initiated outside our hospital, and 23 of them had started recommended therapy after 3 months since the date of biopsy/unscheduled operation. We analyzed clinical prognostic factors and overall survival (OS).

RESULTS

The median age was 28 years (18-67 years), primary tumor was localized axially in 114 patients (63%), metastases at presentation were detected in 51 pts (28%). 5-year OS rate was 65% for patients with localized disease, in metastatic disease it was 15%; the presence and the number of metastases was a prognostic factor. 5-year PFS was significantly better in patients treated at referral center (or when the patients were admitted to referral center within 3 months from the date of biopsy, which was performed outside referral center), comparing to patients treated initially outside referral center; 5-year PFS rates in total population were 28 and 13%, respectively. In terms of OS, unfavorable prognostic factor showing a statistical trend (p = 0.098) was lower dose density of neoadjuvant chemotherapy due to toxicity.

CONCLUSIONS

Approximately two-third of adult patients with localized Ewing sarcoma survive 5 years. In order to improve survival of this patients the multidisciplinary treatment in referral center is mandatory.

Outcomes with nondose-dense chemotherapy for Ewing sarcoma: A practical approach for the developing world

BACKGROUND

The current multidisciplinary approach in the treatment of Ewing sarcoma has improved cure rates, with contemporary dose-dense chemotherapy attaining 5-year event-free survival (EFS) of 73% in localized cases. Dose-intense and dose-dense chemotherapy is difficult in the majority of resource-limited settings with limited access to optimal supportive care. We report on patients with Ewing sarcoma treated on EFT-2001, a nondose-dense chemotherapy protocol.

PROCEDURE

A retrospective analysis was conducted of patients (<15 years) with Ewing sarcoma treated with curative intent during January 2013-June 2017 with an institutional ethics committee-approved nondose-dense protocol (EFT-2001). Local therapy was planned after 9-12 weeks of chemotherapy with metastatic sites addressed with radiotherapy. The study assessed outcomes and prognostic factors.

RESULTS

We analysed 200 patients with M:F ratio of 1.27:1 and metastases in 41 patients (20.5%). At a median follow up of 41.5 months (range 4.5-81.8 months), respective 3-year EFS and overall survival (OS) of the whole cohort is 65.3% (95% confidence interval [CI]: 58.1-71.7%) and 79.3% (95% CI: 72.8-84.5%); for localized and metastatic cohort, 70.9% (95% CI: 62.9-77.5%) and 82.8% (95% CI: 75.7-89.0%); and for metastatic cohort, 42.8% (95% CI: 28.0-58.6%) and 65.3% (95% CI: 47.7-78.3%). Presence of residual disease (morphologic/metabolic) on positron emission tomography-computed tomography scan done 3 months post definitive radiotherapy (hazard ratio [HR] 7.92 [95% CI: 3.46-18.14]) and delay in any form of local control >4 months (HR 3.42 [95% CI: 1.32-8.89]) affected outcomes. Nonrelapse mortality during treatment was 6.5%, mainly due to cardiomyopathy (3.0%) and bacterial sepsis (1.5%). Cardiotoxicity was seen in 11.5% of patients.

CONCLUSIONS

Nondose-dense chemotherapy provides good outcomes with manageable toxicities in a multidisciplinary treatment approach, while reducing cumulative drug exposures in the developing world where dose-intense or dose-dense chemotherapy could potentially increase toxicity, and hence seems a feasible approach in resource-limited settings. Presence of any residual disease post definitive radiotherapy or delay in local control portends poor outcome.

Primary Renal Ewing Sarcoma in Children and Young Adults

The Ewing sarcoma family of tumors (ESFT) are high-grade small round blue cell malignancies traditionally presenting in children and adolescents. The most common site of primary disease is bone, though extraskeletal primary sites are well-recognized. We present 6 cases of primary ESFT of the kidney and 1 case of the adrenal gland. Patients were 11 to 18 years of age at diagnosis. Metastases at diagnosis were present in most cases (n=6). All patients underwent surgery, and most received radiation (n=5). Five patients relapsed after initial remission. Comprehensive review of the primary renal ESFT literature was used to analyze various factors, including age, sex, disease metrics, metastases at diagnoses, and overall survival in a total of 362 cases. Notably, while the general ESFT population has reported rates of metastasis at diagnosis of 20% to 25%, this rate in the renal ESFT population was 53% with a rate of 59% in adolescent and young-adult patients (11 to 24 y). Nodal disease at diagnosis was present in 24% of renal ESFT cases compared with 3.2% in patients with primary skeletal ESFT. While this malignant process may share histologic and molecular features with its bone and soft tissue counterparts, primary renal ESFT presentations seem to be more aggressive and have worse outcomes.

Phase II results from a phase I/II study to assess the safety and efficacy of weekly nab-paclitaxel in paediatric patients with recurrent or refractory solid tumours: A collaboration with the European Innovative Therapies for Children with Cancer Network

BACKGROUND

The phase I component of a phase I/II study defined the recommended phase II dose and established the tolerability of nab-paclitaxel monotherapy in paediatric patients with recurrent or refractory solid tumours. The activity and safety of nab-paclitaxel monotherapy was further investigated in this phase II study.

PATIENTS AND METHODS

Paediatric patients with recurrent or refractory Ewing sarcoma, neuroblastoma or rhabdomyosarcoma received 240 mg/m² of nab-paclitaxel on days 1, 8 and 15 of each 28-day cycle. The primary end-point was the overall response rate (ORR; complete response [CR] + partial response [PR]). Secondary end-points included duration of response, disease control rate (DCR; CR + PR + stable disease [SD]), progression-free survival, 1-year overall survival, safety and pharmacokinetics.

RESULTS

Forty-two patients were enrolled, 14 each with Ewing sarcoma, neuroblastoma and rhabdomyosarcoma. The ORRs were 0%, 0% and 7.1% (1 confirmed PR), respectively. The DCRs were 30.8% (4 SD), 7.1% (1 SD) and 7.1% (1 confirmed PR and 0 SD) in the Ewing sarcoma, neuroblastoma and rhabdomyosarcoma groups, respectively. The median progression-free survival was 13.0, 7.4 and 5.1 weeks, respectively, and the 1-year overall survival rates were 48%, 25% and 15%, respectively. The most common grade III/4IVadverse events were haematologic (neutropenia [50%] and anaemia [48%]), and grade III/IV peripheral neuropathy occurred in 2 patients (14%) in the rhabdomyosarcoma group. Pharmacokinetics analyses revealed that paclitaxel tissue distribution was both rapid and extensive.

CONCLUSIONS

In this phase II study, limited activity was observed; however, the safety of nab-paclitaxel in paediatric patients was confirmed.

TRIAL REGISTRATION

NCT01962103 and EudraCT 2013-000144-26.

Pregnancy-Associated Plasma Protein-A (PAPP-A) in Ewing Sarcoma: Role in Tumor Growth and Immune Evasion

BACKGROUND

Ewing sarcoma (EWS) manifests one of the lowest somatic mutation rates of any cancer, leading to a scarcity of druggable mutations and neoantigens. Immunotherapeutics targeting differentially expressed cell surface antigens could provide therapeutic benefit for such tumors. Pregnancy-associated plasma protein A (PAPP-A) is a cell membrane-associated proteinase produced by the placenta that promotes fetal growth by inducing insulinlike growth factor (IGF) signaling.

METHODS

By comparing RNA expression of cell surface proteins in EWS (n = 120) versus normal tissues (n = 42), we comprehensively characterized the surfaceome of EWS to identify highly differentially expressed molecules. Using CRISPR/Cas-9 and anti-PAPP-A antibodies, we investigated biological roles for PAPP-A in EWS in vitro and in vivo in NSG xenograft models and performed RNA-sequencing on PAPPA knockout clones (n = 5) and controls (n = 3). All statistical tests were two-sided.

RESULTS

EWS surfaceome analysis identified 11 highly differentially overexpressed genes, with PAPPA ranking second in differential expression. In EWS cell lines, genetic knockout of PAPPA and treatment with anti-PAPP-A antibodies revealed an essential survival role by regulating local IGF-1 bioavailability. MAb-mediated PAPPA inhibition diminished EWS growth in orthotopic xenografts (leg area mm2 at day 49 IgG2a control (CTRL) [n = 14], mean = 397.0, SD = 86.1 vs anti-PAPP-A [n = 14], mean = 311.7, SD = 155.0; P = .03; median OS anti-PAPP-A = 52.5 days, 95% CI = 46.0 to 63.0 days vs IgG2a = 45.0 days, 95% CI = 42.0 to 52.0 days; P = .02) and improved the efficacy of anti-IGF-1R treatment (leg area mm2 at day 49 anti-PAPP-A + anti-IGF-1R [n = 15], mean = 217.9, SD = 148.5 vs IgG2a-CTRL; P < .001; median OS anti-PAPP-A + anti-IGF1R = 63.0 days, 95% CI = 52.0 to 67.0 days vs IgG2a-CTRL; P < .001). Unexpectedly, PAPPA knockout in EWS cell lines induced interferon (IFN)-response genes, including proteins associated with antigen processing/presentation. Consistently, gene expression profiles in PAPPA-low EWS tumors were enriched for immune response pathways.

CONCLUSION

This work provides a comprehensive characterization of the surfaceome of EWS, credentials PAPP-A as a highly differentially expressed therapeutic target, and discovers a novel link between IGF-1 signaling and immune evasion in cancer, thus implicating shared mechanisms of immune evasion between EWS and the placenta.

Outcomes of extraskeletal vs. skeletal Ewing sarcoma patients treated with standard chemotherapy protocol

PURPOSE

To compare the outcomes of extraskeletal and skeletal Ewing sarcomas treated with standard chemotherapy protocol.

METHODS

We retrospectively collected data on primary localized skeletal and extraskeletal ES patients. Demographics and disease characteristics were compared between the two groups. The influence of presentation (skeletal vs. extraskeletal) on overall survival (OS) and local recurrence-free survival (LRFS) was assessed and compared by the log-rank test.

RESULTS

A total of 120 patients were included; 29 (24%) had extraskeletal and 91 (76%) had skeletal ES. All patients received vincristine, doxorubicin, and cyclophosphamide alternating with ifosfamide and etoposide (VDC-IE) chemotherapy, with a plan for local control at week 12. At a median follow-up of 38 months, there was no difference in OS between skeletal and extraskeletal ES; 5-year OS 70% and 67% respectively, p = 0.96. Patients with extraskeletal ES had inferior 5-year LRFS compared to skeletal ES; 74% vs. 83%; p = 0.042. Local recurrence occurred at a higher frequency in the extraskeletal group; 28% vs. 11%, p = 0.034, although more extraskeletal patients received adjuvant radiotherapy; 73% vs. 36%, p = 0.01. Among patients who underwent surgery (n = 76), there was no difference in R0 resection rate (skeletal: 89%, extraskeletal: 86%, p = 0.52, or good ( ≥ 90%) tumor necrosis; skeletal: 54%, extraskeletal: 38%, p = 0.31.

CONCLUSION

Patients with localized extraskeletal ES have comparable OS outcomes to patients with skeletal ES utilizing the standard VDC-IE chemotherapy. However, extraskeletal patients are at significantly higher risk for local recurrence.

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.

Clotam enhances anti-proliferative effect of vincristine in Ewing sarcoma cells

Current therapeutic strategies used in Ewing sarcoma (ES) especially for relapsed patients have resulted in modest improvements in survival over the past 20 years. Combination therapeutic approach presents as an alternative to overcoming drug resistance in metastatic ES. This study evaluated the effect of Clotam (tolfenamic acid or TA), a small molecule and inhibitor of Specificity protein1 (Sp1) and survivin for sensitizing ES cell lines to chemotherapeutic agent, vincristine (VCR). ES cells (CHLA-9 and TC-32) were treated with TA or VCR or TA + VCR (combination), and cell viability was assessed after 24/48/72 h. Effect of TA or VCR or TA + VCR treatment on cell cycle arrest and apoptosis were evaluated using propidium iodide, cell cycle assay and Annexin V flow cytometry respectively. The apoptosis markers, caspase 3/7 (activity levels) and cleaved-PARP (protein expression) were measured. Cardiomyocytes, H9C2 were used as non-malignant cells. While, all treatments caused time- and dose-dependent inhibition of cell viability, interestingly, combination treatment caused significantly higher response (~ 80% inhibition, p < 0.05). Cell viability inhibition was accompanied by inhibition of Sp1 and Survivin. TA + VCR treatment significantly (p < 0.05) increased caspase 3/7 activity which strongly correlated with upregulated c-PARP level and Annexin V staining. Cell cycle arrest was observed at G0/G1 (TA) or G2/M (VCR and TA + VCR). All treatments did not cause cytotoxicity in H9C2 cells. These results suggest that TA could enhance the anti-cancer activity of VCR in ES cells. Therefore, TA + VCR combination could be further tested to develop as safe/effective therapeutic strategy for treating ES.

[Ewing sarcoma of the bone. Multidisciplinary approach and oncological results in 88 patients]

Ewing sarcoma of the bone is a rare, highly aggressive tumor that typically affects children and young adults. In Argentina, the lack of Ewing's sarcoma registries reflects in the absence of information regarding prevalence, treatment protocols and patient's outcome. The purpose of this study was to analyze, in a group of patients diagnosed with Ewing sarcoma of the bone, treated with chemotherapy and limb-conserving surgery, their overall survival rate, local recurrence rate, and oncological risk factors. A retrospective research was conducted between 1990 and 2017. Eighty-eight patients with Ewing sarcoma of the bone matched the inclusion criteria. Median age was 14.5 years and median follow-up was 8.8 years. Overall survival rate was 79.5%, 69% and 64% at 2, 5 and 10 years respectively. Negative prognostic factors, associated with less survival rate after univariate analysis, were: bad response to chemotherapy (tumoral necrosis 0-89%), age > 16 years-old, central tumor localization and local recurrence. Gender and tumor size were not significant prognostic factors. After multivariate analysis, response to chemotherapy remained statistical significant. Local recurrence-free survival rate at 2 and 5 years was 87%. Tumor response to chemotherapy (0-89%) was the only significant factor for local recurrence. We consider that limb-salvage surgery, with neoadjuvant and adjuvant chemotherapy, are the mainstays of treatment for Ewing's sarcoma, with an overall survival rate, at 5 years, of 69%. In this population, response to chemotherapy is the most relevant prognostic factor, being associated with both local recurrence and overall survival.

High-Dose Chemotherapy Compared With Standard Chemotherapy and Lung Radiation in Ewing Sarcoma With Pulmonary Metastases: Results of the European Ewing Tumour Working Initiative of National Groups, 99 Trial and EWING 2008

PURPOSE

The R2Pulm trial was conducted to evaluate the effect of busulfan-melphalan high-dose chemotherapy with autologous stem-cell rescue (BuMel) without whole-lung irradiation (WLI) on event-free survival (main end point) and overall survival, compared with standard chemotherapy with WLI in Ewing sarcoma (ES) presenting with pulmonary and/or pleural metastases.

METHODS

From 2000 to 2015, we enrolled patients younger than 50 years of age with newly diagnosed ES and with only pulmonary or pleural metastases. Patients received chemotherapy with six courses of vincristine, ifosfamide, doxorubicin, and etoposide (VIDE) and one course of vincristine, dactinomycin, and ifosfamide (VAI) before either BuMel or seven courses of VAI and WLI (VAI plus WLI) by randomized assignment. The analysis was conducted as intention to treat. The estimates of the hazard ratio (HR), 95% CI, and P value were corrected for the three previous interim analyses by the inverse normal method.

RESULTS

Of 543 potentially eligible patients, 287 were randomly assigned to VAI plus WLI (n = 143) or BuMel (n = 144). Selected patients requiring radiotherapy to an axial primary site were excluded from randomization to avoid excess organ toxicity from interaction between radiotherapy and busulfan. Median follow-up was 8.1 years. We did not observe any significant difference in survival outcomes between treatment groups. Event-free survival was 50.6% versus 56.6% at 3 years and 43.1% versus 52.9% at 8 years, for VAI plus WLI and BuMel patients, respectively, resulting in an HR of 0.79 (95% CI, 0.56 to 1.10; P = .16). For overall survival, the HR was 1.00 (95% CI, 0.70 to 1.44; P = .99). Four patients died as a result of BuMel-related toxicity, and none died after VAI plus WLI. Significantly more patients in the BuMel arm experienced severe acute toxicities than in the VAI plus WLI arm.

CONCLUSION

In ES with pulmonary or pleural metastases, there is no clear benefit from BuMel compared with conventional VAI plus WLI.

Gene expression and immunohistochemical analyses identify SOX2 as major risk factor for overall survival and relapse in Ewing sarcoma patients

BACKGROUND

Up to 30-40% of Ewing sarcoma (EwS) patients with non-metastatic disease develop local or metastatic relapse within a time span of 2-10 years. This is in part caused by the absence of prognostic biomarkers that can identify high-risk patients and thus assign them to risk-adapted monitoring and treatment regimens. Since cancer stemness has been associated with tumour relapse and poor patient outcomes, we investigated in the current study the prognostic potential SOX2 (sex determining region Y box 2) - a major transcription factor involved in development and stemness - which was previously described to contribute to the undifferentiated phenotype of EwS.

METHODS

Two independent patient cohorts, one consisting of 189 retrospectively collected EwS tumours with corresponding mRNA expression data (test-cohort) and the other consisting of 141 prospectively collected formalin-fixed and paraffin-embedded resected tumours (validation and cohort), were employed to analyse SOX2 expression levels through DNA microarrays or immunohistochemistry, respectively, and to compare them with clinical parameters and patient outcomes. Two methods were employed to test the validity of the results at both the mRNA and protein levels.

FINDINGS

Both cohorts showed that only a subset of EwS patients (16-20%) expressed high SOX2 mRNA or protein levels, which significantly correlated with poor overall survival. Multivariate analyses of our validation-cohort revealed that high SOX2 expression represents a major risk-factor for poor survival (HR = 3·19; 95%CI 1·74-5·84; p < 0·01) that is independent from metastasis and other known clinical risk-factors at the time of diagnosis. Univariate analyses demonstrated that SOX2-high expression was correlated with tumour relapse (p = 0·002). The median first relapse was at 14·7 months (range: 3·5-180·7).

INTERPRETATION

High SOX2 expression constitutes an independent prognostic biomarker for EwS patients with poor outcomes. This may help to identify patients with localised disease who are at high risk for tumour relapse within the first two years after diagnosis.

FUNDING

The laboratory of T. G. P. Grünewald is supported by grants from the 'Verein zur Förderung von Wissenschaft und Forschung an der Medizinischen Fakultät der LMU München (WiFoMed)', by LMU Munich's Institutional Strategy LMUexcellent within the framework of the German Excellence Initiative, the 'Mehr LEBEN für krebskranke Kinder - Bettina-Bräu-Stiftung', the Walter Schulz Foundation, the Wilhelm Sander-Foundation (2016.167.1), the Friedrich-Baur foundation, the Matthias-Lackas foundation, the Barbara & Hubertus Trettner foundation, the Dr. Leopold & Carmen Ellinger foundation, the Gert & Susanna Mayer foundation, the Deutsche Forschungsgemeinschaft (DFG 391665916), and by the German Cancer Aid (DKH-111886 and DKH-70112257). J. Li was supported by a scholarship of the China Scholarship Council (CSC), J. Musa was supported by a scholarship of the Kind-Philipp foundation, and T. L. B. Hölting by a scholarship of the German Cancer Aid. M. F. Orth and M. M. L. Knott were supported by scholarships of the German National Academic Foundation. G. Sannino was supported by a scholarship from the Fritz-Thyssen Foundation (FTF-40.15.0.030MN). The work of U. Dirksen is supported by grants from the German Cancer Aid (DKH-108128, DKH-70112018, and DKH-70113419), the ERA-Net-TRANSCAN consortium (project number 01KT1310), and Euro Ewing Consortium (EEC, project number EU-FP7 602,856), both funded under the European Commission Seventh Framework Program FP7-HEALTH (http://cordis.europa.eu/), the Barbara & Hubertus Trettner foundation, and the Gert & Susanna Mayer foundation. G. Hardiman was supported by grants from the National Science Foundation (SC EPSCoR) and National Institutes of Health (U01-DA045300). The laboratory of J. Alonso was supported by Instituto de Salud Carlos III (PI12/00816; PI16CIII/00026); Asociación Pablo Ugarte (TPY-M 1149/13; TRPV 205/18), ASION (TVP 141/17), Fundación Sonrisa de Alex & Todos somos Iván (TVP 1324/15).

New Insights about the Wnt/β-Catenin Signaling Pathway in Primary Bone Tumors and Their Microenvironment: A Promising Target to Develop Therapeutic Strategies?

Osteosarcoma and Ewing sarcoma are the most common malignant primary bone tumors mainly occurring in children, adolescents and young adults. Current standard therapy includes multidrug chemotherapy and/or radiation specifically for Ewing sarcoma, associated with tumor resection. However, patient survival has not evolved for the past decade and remains closely related to the response of tumor cells to chemotherapy, reaching around 75% at 5 years for patients with localized forms of osteosarcoma or Ewing sarcoma but less than 30% in metastatic diseases and patients resistant to initial chemotherapy. Despite Ewing sarcoma being characterized by specific EWSR1-ETS gene fusions resulting in oncogenic transcription factors, currently, no targeted therapy could be implemented. It seems even more difficult to develop a targeted therapeutic strategy in osteosarcoma which is characterized by high complexity and heterogeneity in genomic alterations. Nevertheless, the common point between these different bone tumors is their ability to deregulate bone homeostasis and remodeling and divert them to their benefit. Therefore, targeting different actors of the bone tumor microenvironment has been hypothesized to develop new therapeutic strategies. In this context, it is well known that the Wnt/β-catenin signaling pathway plays a key role in cancer development, including osteosarcoma and Ewing sarcoma as well as in bone remodeling. Moreover, recent studies highlight the implication of the Wnt/β-catenin pathway in angiogenesis and immuno-surveillance, two key mechanisms involved in metastatic dissemination. This review focuses on the role played by this signaling pathway in the development of primary bone tumors and the modulation of their specific microenvironment.

Multimodal Treatment in Pelvic Ewing Sarcoma: A Prognostic Factor Analysis

BACKGROUND

Although multidisciplinary therapies have improved local control and overall survival in Ewing sarcoma (ES), the prognosis of pelvic lesions remains markedly worse than that of limb ES.

METHODS

We retrospectively evaluated the influence of the type of local treatment, margins, necrosis and sacrum involvement on overall survival (OS) and disease-free survival (DFS) in a series of 21 non-metastatic pelvic ES.

RESULTS

The average follow-up was 46.3 months (range 3-156). Only one patient had recurrence, at 11 months after surgery. Eight patients showed pulmonary metastasis and five showed bone metastases. Necrosis was the only significant prognostic factor for overall survival at 5 years (p=0.0132) and disease-free survival (p=0.0086). Overall survival at 5 years was 40.1%.

CONCLUSION

Local control in pelvic Ewing sarcoma is comparable for patients treated with surgery (S), surgery plus radiotherapy (S/RT), or definitive radiotherapy (RT). The combination of surgery plus radiotherapy could be indicated in cases of large tumor, a poor necrosis response (< 90%), or an inadequate margin with involvement of the sacrum. A poor response to neoadjuvant therapy is a significant risk factor for both local control and overall survival.

Retrospective Analysis of Outcomes of Patients with Relapsed, Refractory and Metastatic Sarcomas who have received Metronomic Chemotherapy

INTRODUCTION

Paediatric soft tissue sarcoma treatments and outcomes have improved significantly in the last few decades. However, a significant number of patients still succumb to the disease. In low-middle income countries there are dual problems of advanced disease at presentation and financial burden leading to poor compliance to therapy. Hence, we designed a low-cost oral metronomic chemotherapy protocol for these patients and studied the responses and toxicities to therapy in a tertiary referral hospital.

PATIENTS AND METHODS

This is retrospective, single institutional, observational study. We retrospectively reviewed data of patients with relapsed, refractory or metastatic soft tissue sarcoma (STS) [ Ewing Sarcoma (ES); Rhabdomyosarcoma (RMS) or other STS] who were treated with the metronomic protocol of oral Tamoxifen, Etoposide and Cyclophosphamide (TEC) during the period April 1998 to September 2013, at the Tata Memorial Hospital, Parel, Mumbai. Patients with ES and RMS were primarily treated on our Institutional protocols. The patients included in the analysis were those who had relapsed after the primary protocols and then treated with metronomic TEC protocol; or those with primary refractory or metastatic disease (RMS, ES) and received metronomic TEC therapy.

RESULTS

49 patients were enrolled. Among the 49 patients, 32 were diagnosed ES, 13 RMS and 4 other STS. For the whole cohort response rates (RR) were 59% and clinical benefit rate (CBR) was 79%. Patients in the study were grouped into the following subgroups. Systemic recurrent/relapsed disease (N=24), metastatic disease at presentation (N=15) and local disease (refractory/recurrent) (N=10). None of the patients required blood or platelet support or admission for supportive care. The PFS for the above groups were 16.8 months, 12.5 months and 126.68 months respectively. This compares favorably with other historical cohorts in a similar setting.

CONCLUSIONS

This study provides a preliminary evidence efficacy and tolerability of metronomic chemotherapy in poor risk ES and RMS. It also demonstrates that with this low-cost low risk treatment few patients could go into long term remissions despite high disease burden.

Prognostic factors and survival in Ewing's sarcoma treated by limb salvage surgery

PURPOSE

Survival in Ewing's sarcoma (ES) has increased with the use of chemotherapy. Surgical techniques such as limb salvage (LS) have been developed. Survival and adverse events have been widely studied in general series of ES, but there are few specific series of ES cases treated by LS, despite this being the most commonly used (surgical) approach. The aim of this study was to determine survival and prognostic factors in ES patients undergoing LS.

PATIENTS AND METHODS

We analysed all ES patients treated between January 1984 and May 2008 and selected all those treated by systemic multimodal therapy and LS. We assessed the influence of patient characteristics, tumour parameters and therapeutic results in event-free survival (EFS).

RESULTS

Ninety patients were included. Fifty of them were treated by systemic multimodal therapy and locally by LS. ean age was 20 years. Overall survival (OS) was 68.8% and EFS was 60.6% at years. In the univariate analysis, pelvic location, age and response to chemotherapy were associated with poor prognosis. After multivariate analysis, poor response to treatment, pelvis location and age between 12 and 17 years were found to be independent prognostic factors. Dissemination at diagnosis was not a prognostic factor.

CONCLUSIONS

OS and EFS in ES treated by LS were similar to findings in previous ES studies. factors are no different, except for the presence of metastasis at diagnosis.

Antitumor effects of β-elemene via targeting the phosphorylation of insulin receptor

Ewing sarcoma family tumors (ESFTs) are a group of aggressive and highly metastatic tumors lacking efficient therapies. Insulin-like growth factor 1 receptor (IGF1R) blockade is one of the most efficient targeting therapy for ESFTs. However, the appliance is obstructed by drug resistance and disease recurrence due to the activation of insulin receptor (IR) signaling induced by IGF1R blockade. Herein β-elemene, a compound derived from natural plants, exhibited a remarkable proliferation repression on ESFT cells, which was weakened by a caspase inhibitor Z-VAD. β-elemene in combination with IGF1R inhibitors enhanced markedly the repression on cellular proliferation and mTOR activation by IGF1R inhibitors and suppressed the PI3K phosphorylation induced by IGF1R inhibitors. To investigate the mechanisms, we focused on the effects of β-elemene on IR signaling pathway. β-elemene significantly suppressed the insulin-driven cell growth and the activation of mTOR and PI3K in tumor cells, while the toxicity to normal hepatocytes was much lower. Further, the phosphorylation of IR was found to be suppressed notably by β-elemene specifically in tumor cells other than normal hepatocytes. In addition, β-elemene inhibited the growth of ESFT xenografts in vivo, and the phosphorylation of IR and S6 ribosomal protein was significantly repressed in the β-elemene-treated xenografts. These data suggest that β-elemene targets IR phosphorylation to inhibit the proliferation of tumor cells specifically and enhance the effects of IGF1R inhibitors. Thus, this study provides evidence for novel approaches by β-elemene alone or in combination with IGF1R blockades in ESFTs and IR signaling hyperactivated tumors.

Ewing sarcoma, analysis of survival at 6 years with multidisciplinary therapy

PURPOSE

The purpose of this study is to present our series of Ewing sarcoma cases and the survival data obtained in the medium term, using a multidisciplinary therapy protocol.

MATERIAL, METHODS AND RESULTS

Forty-one Ewing sarcomas were diagnosed, treated and followed-up in our hospital between 2004 and 2009 with an average age of 18.29 years. Seventy-eight percent were to Ewing sarcoma of the bone, the femur being the most frequent location. Sixty-eight percent had a localized stage at the time of diagnosis. At the end of follow-up, 40% of the patients did not survive, most died within the first 5 years of follow-up.

DISCUSSION

In Spain, Ewing sarcoma is the most common primary malignant bone tumour in childhood, ahead of osteosarcoma. Its survival rate has increased greatly in the last 40 years, improvement attributable mainly to the aggressive use of chemotherapy and to multidisciplinary treatment, but its prognosis remains very poor, especially for those with metastasis at diagnosis, the main adverse prognostic factor. Because of its high mortality, many authors consider it a disseminated disease from the beginning, with non- detectable micrometastasis that condition final survival.

CONCLUSIONS

Early diagnosis and multidisciplinary therapy in referral centres are the best strategies currently available to us to provide these patients the maximum possibilities of cure of this disease.

Timing of Local Therapy Affects Survival in Ewing Sarcoma

PURPOSE

We aimed to investigate the relationship between survival and time to local therapy after initiation of up-front chemotherapy in the treatment of patients with localized Ewing sarcoma.

METHODS AND MATERIALS

The National Cancer Database was queried for patients with localized Ewing sarcoma treated with primary chemotherapy and subsequent local therapy. Kaplan-Meier survival curves were generated for patients initiating local therapy 6 to 15 weeks and ≥16 weeks after chemotherapy initiation. Multivariable binomial logistic regression was used to identify factors associated with prolonged time to local therapy. A multivariable Cox proportional hazards model was used to identify factors associated with overall survival (OS).

RESULTS

The final cohort included 1318 patients. A higher proportion of patients initiating local therapy 6 to 15 weeks after chemotherapy initiation versus ≥16 weeks after chemotherapy initiation were ≤21 years old (79.5% vs 72.0%; P = .004). Age >21 years (P < .001; hazard ratio, 1.65; 95% confidence interval, 1.28-2.12), tumor size >8 cm (P = .016), and time to local therapy ≥16 weeks (P = .005; hazard ratio, 1.41; 95% confidence interval, 1.11-1.80) were associated with reduced OS; after review of margin status, negative margins were associated with improved OS compared with gross disease (P = .029). Patients initiating local therapy at 6 to 15 weeks versus ≥16 weeks had a 5-year OS of 78.7% versus 70.4% and a 10-year OS of 70.3% versus 57.1%, respectively (P < .001). The difference in OS according to time to local therapy was particularly more important in patients receiving radiation therapy alone. Age >21 years and treatment by radiation therapy alone were associated with delayed time (>16 weeks) to local therapy, whereas private insurance and income >$48,000 were less likely to be associated with delayed local therapy.

CONCLUSIONS

Delayed time to local therapy ≥16 weeks after chemotherapy initiation was independently associated with worse survival in patients with localized Ewing sarcoma.

[Survival of pediatric patients with Ewing sarcoma treated at Semmelweis University]

The survival of children treated with Ewing sarcoma at Semmelweis University were investigated. Pediatric patients with Ewing sarcoma treated at Semmelweis University from 2001 through 2013 were analyzed in terms of overall survival and clinical factors (age, primary localization and extent of the tumor, time interval from primary complaints to diagnosis). For statistical analysis Kaplan-Meier estimated survival and log rank test were applied. Mean age and follow-up time of the 78 patients were 11.16 and 6.29 years, respectively. In 57% of patients time interval from primary symptoms to diagnosis was less than half year. In 53.8% of the patients the disease was metastatic at primary diagnosis (pulmonary only: 29.5%, any other: 24.3%). 5- and 10-year overall survival of patients were 68.1% and 60.4%, respectively. Among the analyzed factors, the presence of metastasis impaired 5-year overall survival significantly (88.5% for localized disease, 63.5% for pulmonary only and 40.9% for any other metastasis). The survival rate of pediatric patients with Ewing sarcoma treated at Semmelweis University is similar to the result in Western European countries.

Treatment results of childhood Ewing's sarcoma of the bone in Serbia

PURPOSE

The purpose of this study was to present treatment results of childhood Ewing's sarcoma (ES) of the bone in Serbia and to analyze prognostic factors.

METHODS

We performed a detailed analysis on a series of 107 patients with ES of the bone treated at the Institute for Oncology and Radiology of Serbia between 2000 and 2014, using modern multimodal therapy.

RESULTS

Median age at the time of diagnosis was 14 years, with 56.07% of the patients being ≤14 years. There was a male predominance (59.81%). The most common primary sites were pelvis (25.23%), femur (17.76%) and tibia (12.15%). Thirty-four patients (31.78%) had metastatic disease, 17 of which had isolated lung metastases, 9 bone metastases and 8 patients had both. Tumor size ≤ 8 cm had 38.32% and >8 cm had 61.68% patients. Overall, 51.4% patients underwent surgery and radiotherapy as a local treatment modality after neoadjuvant chemotherapy. Radiotherapy alone was performed in 24 patients. The 5-year overall survival (OS) was 43.8%. For patients with localized disease, the 5-year OS was 56.4% and for patients with metastatic disease 17.6%. In patients with initially nonmetastatic disease, age under 14 years, with tumor size <8 cm and a good response to the neoadjuvant chemotherapy, the OS correlated with better outcome.

CONCLUSIONS

Modern multidisciplinary approach in treatment of childhood ES of the bone in accordance with the recommended pediatric protocols, gives good treatment results. Therapy should be performed in referral centers.

Impact of Whole Lung Irradiation on Survival Outcome in Patients With Lung Relapsed Ewing Sarcoma

PURPOSE

There is no standard treatment procedure for relapsed Ewing sarcoma (EwS). This retrospective analysis evaluates the survival outcome in patients with an isolated pulmonary relapse of EwS treated with whole lung irradiation (WLI) in addition to second line chemotherapy (Ctx).

METHODS AND MATERIALS

In our study, 136 patients with pulmonary relapsed EwS who were registered in the relapse register of the Cooperative Ewing Sarcoma Study group or the Sarcoma Relapse Registry for relapsed sarcoma of bone and soft tissues were analyzed. All patients received relapse Ctx or an additional total resection of lung metastasis. Of these patients, 88 (median age, 21 years; range, 7-52 years) achieved a second remission by the relapse treatment. Of these 88 patients, 48 patients received an additional WLI. The 3-year progression-free survival (PFS) and 3-year overall survival (OS) were analyzed (median follow-up, 3 years; range, 7 months to 11 years and 9 months). Additional prognostic factors for survival outcomes, including the response of lung metastases to Ctx, were also estimated.

RESULTS

The survival outcome was significantly improved after WLI when analyzing the entire group of pulmonary relapsed patients: 3-year PFS 36% (+WLI) versus 14% (-WLI) (P = .001); 3- year OS 47% (+WLI) versus 33% (-WLI) (P = .007). The 3-year PFS in patients with complete remission of lung relapse receiving WLI (n = 48) compared with those without WLI (n = 40), was 37% (+WLI) versus 21% (-WLI) (P = .18). The site of the primary tumor and the response of pulmonary lesions to Ctx were significant prognostic indicators for survival in patients treated with WLI. No severe pulmonary function disorders or lung toxicities were observed after WLI treatment in both pediatric and adult patients.

CONCLUSIONS

The WLI does not correlate with improved OS in patients with pulmonary relapsed EwS. However, a marginal trend toward superior PFS and improved local control of pulmonary disease suggests the application of WLI in patients with EwS with isolated lung relapse and second clinical remission.

Ewing sarcoma of the head and neck: The Mayo Clinic experience

BACKGROUND

Treatment options of Ewing sarcoma of the head and neck include surgery, radiotherapy (RT), and chemoradiotherapy. However, local control can be challenging.

METHODS

We conducted a retrospective review of all patients with head and neck Ewing sarcoma treated from 1972 to 2015 at a single tertiary care hospital.

RESULTS

Seventeen patients met criteria (median 21 years, range 5-58 years; 5 women). Mean follow-up was 10.4 years (range 2.2-39 years). Tumors occurred commonly in the cervical spine (5/17), the skull (3/17), and the paranasal sinuses (3/17). A total of 14 of 17 patients underwent surgical resection, 9 with gross total resection. After multimodality therapy, the 5-year overall survival (OS) and recurrence-free survival (RFS) was 87% and 75%, respectively.

CONCLUSION

Combined multimodal treatment resulted in a 5-year OS and RFS of 87% and 75%, respectively. Aggressive surgical resection with adjuvant chemoradiotherapy should be considered. Although negative margin surgery is the goal, subtotal resection may be acceptable in the setting of adjuvant treatment.

Serum Lactate Dehydrogenase (LDH) as a Tumor Marker in Ewing's Sarcoma

The pretreatment serum lactic acid dehydrogenase (LDH) level of 246 patients with Ewing's sarcoma of bone (47 metastatic and 199 localized at presentation) was examined to evaluate the use of LDH as a tumor marker. The percentage of patients with increased serum LDH levels was significantly higher in the metastatic group than in the group of patients with localized disease (83 % vs 41 %; p < 0.01). In the latter group the relapse rate after treatment with combined therapy was significantly higher in patients with an elevated serum LDH at admission than in those with normal serum levels (68.2 % vs 39.3 %; p < 0.01). After local treatment, in 73 out of 82 patients with an elevated serum LDH at admission the enzyme level normalized whereas in 9 it fell but never reached a normal value. The rate of relapse in these two groups was respectively 64 % and 100 %. The value of serum LDH at the time of recurrence, determined in 62 patients, was elevated in 50 (80.7 %). These data demonstrate that in Ewing's sarcoma of bone pretreatment serum LDH levels have a definitive value in establishing the prognosis and could also be used in evaluating the response to therapy. A persistent elevated value of serum LDH, or an increasing value after a transient normalization, is usually followed by relapse.

Ten Years Experience with Ewing's Sarcoma

The series comprises 57 consecutive patients with Ewing's sarcoma admitted to the National Cancer Institute of Milan from 1965 to 1976. In 75 % the disease was confined to one bone, while in 25 % multiple bone and/or visceral lesions were present. Patients with clinically localized tumor treated before 1971 with local therapy, showed a median disease-free survival of 5 months. After 1971, radiotherapy and/or surgery to local tumor was combined with multiple drug chemotherapy (ADM, VCR, CTX) and the projected median disease-free survival increased to 24+ months. In previously untreated patients with advanced tumor adriamycin, used as single drug, achieved an overall response rate of 73 %. This is comparable to that achieved by a new combination including ADM, VCR, CTX, CCNU (75%). This multiple drug regimen is, however, expected to prolong the duration of response.

Survival outcome among patients with Ewing's sarcoma of bones and joints: a population-based cohort study

BACKGROUND

The aim here was to elucidate the current survival condition of patients diagnosed with Ewing's sarcoma of the bones and joints and determine independent risk factors associated with the prognosis.

DESIGN AND SETTING

Retrospective cohort study based on the Surveillance, Epidemiology and End Results (SEER) database in the United States.

METHODS

We identified 397 patients who were diagnosed with Ewing's sarcoma of the bones and joints between January 2004 and December 2013. The multivariate Cox proportional hazards model was used to determine factors associated with the risk of death by adjusting for various factors.

RESULTS

The one, two and five-year disease-specific survival rates were 89.08%, 78.08% and 62.47%, respectively. The factors related to death were age (≥ 18 years versus < 18 years; hazard ratio, HR = 1.77; 95% confidence interval, CI: 1.38-2.31); tumor site (extremity versus spine and pelvis; HR = 2.03; 95% CI: 1.31-2.62); tumor size (> 10 cm versus ≤ 10 cm; HR = 1.78; 95% CI: 1.34-2.56); and type of treatment (surgery alone versus radiotherapy with surgery; HR = 0.51; 95% CI: 0.38-0.89; or radiotherapy alone versus radiotherapy with surgery; HR = 1.61; 95% CI: 1.10-2.39; or no treatment versus radiotherapy with surgery; HR = 1.86; 95% CI: 1.23, 2.58).

CONCLUSIONS

Patients with Ewing's sarcoma showed poor survival in situations of age ≥ 18 years, tumor size > 10 cm, receiving radiotherapy alone and receiving no treatment. Patients undergoing surgery alone had better survival.

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

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

GEIS-21: a multicentric phase II study of intensive chemotherapy including gemcitabine and docetaxel for the treatment of Ewing sarcoma of children and adults: a report from the Spanish sarcoma group (GEIS)

BACKGROUND

First Spanish trial of Ewing sarcoma (ES) including adults and children with the aim to test the efficacy of Gemcitabine and Docetaxel (G/D) in newly diagnosed high-risk (HR) patients.

METHODS

This was a prospective, multicentric, non-randomised, open study for patients ⩽40 years with newly diagnosed ES. HR patients (metastatic, axial-pelvic primaries or bone marrow micrometastasis) received 2 window cycles of G/D. Patients with an objective response (OR) to G/D received 12 monthly cycles of G/D after completion of mP6. The primary end point was the OR rate to the G/D window phase and the event-free survival (EFS) and overall survival (OS) for all patients. The study is registered at ClinicalTrials.gov (identifier: NCT00006734).

RESULTS

Forty-three patients were enroled, median age 17 years (range, 3-40). After a median follow-up of 43.4 months, the 5-year OS rate is 55.0% (95% CI, 41-74%) with an EFS of 50.0% (95% CI, 36-68%). The 5-year OS and EFS rates for standard risk (SR) patients was 76.0% (95% CI, 57-100%) and 71.0% (CI, 54-94%); for HR 36.0% (CI, 20-65%) and 29.0% (CI, 15-56%). Twelve of 17 (70.6%) high-risk (HR) patients showed an OR (7 PR and 5 SD) to G/D window therapy. The 5-year OS rate for patients ⩽18 years of age was 74.0% (CI, 56-97%) and 31.0% for >18 years (95% CI, 15-66%), P<0.001. Grade 4 adverse events during mP6 occurred in 28/39 of patients (72%) and did not correlate with age. Multivariate survival analyses with <18 vs ⩾18 and risk groups significant differences, P<0.00001. Using a Cox model for OS, both age and risk group were statistically significant (P=0.0011 and P=0.0065, respectively).

CONCLUSIONS

Age at diagnosis is an independent prognostic factor superior to the presence of metastases with 18 years as the strongest cut-off. The mP6 regimen provided survival curves that plateau at 3 years and G/D produced significant responses in HR-ES that is worth further exploring.

Identification of Mithramycin Analogues with Improved Targeting of the EWS-FLI1 Transcription Factor

PURPOSE

The goal of this study was to identify second-generation mithramycin analogues that better target the EWS-FLI1 transcription factor for Ewing sarcoma. We previously established mithramycin as an EWS-FLI1 inhibitor, but the compound's toxicity prevented its use at effective concentrations in patients.

EXPERIMENTAL DESIGN

We screened a panel of mithralogs to establish their ability to inhibit EWS-FLI1 in Ewing sarcoma. We compared the IC50 with the MTD established in mice to determine the relationship between efficacy and toxicity. We confirmed the suppression of EWS-FLI1 at the promoter, mRNA, gene signature, and protein levels. We established an improved therapeutic window by using time-lapse microscopy to model the effects on cellular proliferation in Ewing sarcoma cells relative to HepG2 control cells. Finally, we established an improved therapeutic window using a xenograft model of Ewing sarcoma.

RESULTS

EC-8105 was found to be the most potent analogue and was able to suppress EWS-FLI1 activity at concentrations nontoxic to other cell types. EC-8042 was substantially less toxic than mithramycin in multiple species but maintained suppression of EWS-FLI1 at similar concentrations. Both compounds markedly suppressed Ewing sarcoma xenograft growth and inhibited EWS-FLI1 in vivo

CONCLUSIONS

These results provide a basis for the continued development of EC-8042 and EC-8105 as EWS-FLI1 inhibitors for the clinic. Clin Cancer Res; 22(16); 4105-18. ©2016 AACR.

Non-Metastatic Pelvic Ewing's Sarcoma : oncologic outcomes and evaluation of prognostic factors

We are reporting our experience on patients with -pelvic Ewing's Sarcoma treated in our unit. We retrospectively reviewed a series of patients with non-metastatic pelvic Ewing's sarcoma treated between 1977 and 2009. Patients were classified into three groups according to the local treatment received : Group 1. radiotherapy-chemo ; Group 2. surgery-chemo and Group 3. radiotherapy-surgery-chemo. Recurrence free and overall survival rates were calculated using the Kaplan-Meier method. Influence of various factors (age at diagnosis, gender, tumour site and size, chemotherapy response, surgical margins and type of treatment) on survival was assessed with a logistic regression model. A total of 85 patients were treated with a mean follow-up of 65.8 months and mean -tumour volume of 435ml. The 5-year survival for all patients was 40.7% decreased to 36.2% at 10 years. A significant prognostic factor identified was chemotherapy response only. There was a trend for improved survival and local control rates for patients who had chemotherapy and surgery and the results were apparent for all tumours irrespective of size but not statistically significant. Currently, the optimal management of pelvic Ewing's sarcoma is contro-versial but our study shows a trend for improved -survival for patients treated with chemotherapy and surgery.

Outcomes of 50 Patients With Ewing Sarcoma Family of Tumors Treated at a Single Institution in Taiwan

To identify the prognostic factors and long-term outcome of the Ewing sarcoma family of tumors (ESFT), data on 50 patients with ESFT treated at Taipei Veterans General Hospital between February 1991 and March 2014 were retrospectively considered. The influence of patient demographics, tumor features, and clinical and therapeutic parameters on overall survival (OS) and progression-free survival (PFS) rates were assessed. The results revealed that 21 of the 50 patients (42%) were metastatic at diagnosis. The median follow-up time was 1.8 years. The 5-year OS and PFS for patients who were nonmetastatic were 61.6% and 55.5%, respectively, and 18.8% and 15.4% for patients who were metastatic, respectively. The key adverse prognostic factor was metastasis at diagnosis. Radiotherapy for local control was associated with improved PFS. The high rate of primary metastasis and poorer outcomes of nonmetastatic ESFT compared with results from Western studies, along with previously reported low rates of ESFT in Taiwanese people, suggest that genetic factors play a role in the pathogenesis of ESFT and chemotherapy pharmacokinetics and pharmacodynamics. Radiotherapy in local treatment should be considered more aggressively in Taiwanese patients with ESFT.

Prognostic Value of SUVmax Measured by Pretreatment Fluorine-18 Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography in Patients with Ewing Sarcoma

Aim

The aim of this retrospective study was to determine whether glucose metabolism assessed by using Fluorine-18 (F-18) fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) provides prognostic information independent of established prognostic factors in patients with Ewing sarcoma.

Methods

We retrospectively reviewed the medical records of 34 patients (men, 19; women, 15; mean age, 14.5 ± 9.7 years) with pathologically proven Ewing sarcoma. They had undergone F-18 FDG PET/CT as part of a pretreatment workup between September 2006 and April 2012. In this analysis, patients were classified by age, sex, initial location, size, and maximum standardized uptake value (SUVmax). The relationship between FDG uptake and survival was analyzed using the Kaplan-Meier method with the log-rank test and Cox’s proportional hazards regression model.

Results

The median survival time for all 34 subjects was 999 days and the median SUV by using PET/CT was 5.8 (range, 2–18.1). Patients with a SUVmax ≤ 5.8 survived significantly longer than those with a SUVmax > 5.8 (median survival time, 1265 vs. 656 days; p = 0.002). Survival was also found to be significantly related to age (p = 0.024), size (p = 0.03), and initial tumor location (p = 0.036). Multivariate analysis revealed that a higher SUVmax (p = 0.003; confidence interval [CI], 3.63–508.26; hazard ratio [HR], 42.98), older age (p = 0.023; CI, 1.34–54.80; HR, 8.59), and higher stage (p = 0.03; CI, 1.21–43.95; HR, 7.3) were associated with worse overall survival.

Conclusions

SUVmax measured by pretreatment F-18-FDG PET/CT can predict overall survival in patients with Ewing sarcoma.

Identification of Discrete Prognostic Groups in Ewing Sarcoma

BACKGROUND

Although multiple prognostic variables have been proposed for Ewing sarcoma (EWS), little work has been done to further categorize these variables into prognostic groups for risk classification.

PROCEDURE

We derived initial prognostic groups from 2,124 patients with EWS in the SEER database. We constructed a multivariable recursive partitioning model of overall survival using the following covariates: age; stage; race/ethnicity; sex; axial primary; pelvic primary; and bone or soft tissue primary. Based on this model, we identified risk groups and estimated 5-year overall survival for each group using Kaplan-Meier methods. We then applied these groups to 1,680 patients enrolled on COG clinical trials.

RESULTS

A multivariable model identified five prognostic groups with significantly different overall survival: (i) localized, age <18 years, non-pelvic primary; (ii) localized, age <18, pelvic primary or localized, age ≥18, white, non-Hispanic; (iii) localized, age ≥18, all races/ethnicities other than white, non-Hispanic; (iv) metastatic, age <18; and (v) metastatic, age ≥18. These five groups were applied to the COG dataset and showed significantly different overall and event-free survival based upon this classification system (P < 0.0001). A sub-analysis of COG patients treated with ifosfamide and etoposide as a component of therapy evaluated these findings in patients receiving contemporary therapy.

CONCLUSIONS

Recursive partitioning analysis yields discrete prognostic groups in EWS that provide valuable information for patients and clinicians in determining an individual patient's risk of death. These groups may enable future clinical trials to adjust EWS treatment according to individualized risk.

[Demographic Analysis of Patients with Osteosarcoma, Chonddrosarcoma, Ewing's Sarcoma from one Sarcoma Center in Switzerland]

Retrospective analysis of presentation, diagnosis and outcome of patients with osteosarcoma, chondrosarcoma and Ewing's sarcoma was performed for a single Sarcoma Center in Zurich at the University Hospital Balgrist. 201 patients were included. Overall survival at five and ten years were 74 ± 6%, 69 ± 7% for osteosarcoma (n = 85, since 2000), 85 ± 7%, 80 ± 9% for Ewing's sarcoma (n = 43, since 1990) and 86 ± 5%, 78 ± 9% for chondrosarcoma (n = 73, since 2000). The here presented overall survival rates from a single Sarcoma Center in Switzerland appear to be equivalent to other large international monocenter studies. The presentation and epidemiology of these patients are in accordance with large multicenter epidemiological studies. A nationwide sarcoma database (SwissSARCOS; www.sarcoma.ch) seems indispensable for more detailed analysis and quality management in such rare diseases.

A phase II study to determine the efficacy and safety of oral treosulfan in patients with advanced pre-treated Ewing sarcoma ISRCTN11631773

We report a prospective Phase II study of efficacy and toxicity for oral treosulfan in advanced Ewing sarcoma. Twenty patients, median age 19 years (range 7-39) from five UK sites, were treated with oral treosulfan 1 g/m(2) daily for 7 days in 28. Primary endpoint was objective response rate. Best response was stable disease in one patient. All patients died of progressive disease, after median 6.41 months. Median progression free survival was 1.8 months. Toxicity was minimal. No activity was demonstrated for treosulfan at this dose. Progression free survival data should be able to be used for comparison when planning future clinical trials.

Clinical and biochemical function of polymorphic NR0B1 GGAA-microsatellites in Ewing sarcoma: a report from the Children's Oncology Group

BACKGROUND

The genetics involved in Ewing sarcoma susceptibility and prognosis are poorly understood. EWS/FLI and related EWS/ETS chimeras upregulate numerous gene targets via promoter-based GGAA-microsatellite response elements. These microsatellites are highly polymorphic in humans, and preliminary evidence suggests EWS/FLI-mediated gene expression is highly dependent on the number of GGAA motifs within the microsatellite.

OBJECTIVES

Here we sought to examine the polymorphic spectrum of a GGAA-microsatellite within the NR0B1 promoter (a critical EWS/FLI target) in primary Ewing sarcoma tumors, and characterize how this polymorphism influences gene expression and clinical outcomes.

RESULTS

A complex, bimodal pattern of EWS/FLI-mediated gene expression was observed across a wide range of GGAA motifs, with maximal expression observed in constructs containing 20-26 GGAA motifs. Relative to white European and African controls, the NR0B1 GGAA-microsatellite in tumor cells demonstrated a strong bias for haplotypes containing 21-25 GGAA motifs suggesting a relationship between microsatellite function and disease susceptibility. This selection bias was not a product of microsatellite instability in tumor samples, nor was there a correlation between NR0B1 GGAA-microsatellite polymorphisms and survival outcomes.

CONCLUSIONS

These data suggest that GGAA-microsatellite polymorphisms observed in human populations modulate EWS/FLI-mediated gene expression and may influence disease susceptibility in Ewing sarcoma.

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.

Survival and prognostic factors in adult patients with recurrent or refractory ewing sarcoma family tumours: a 13-years retrospective study in Turkey

AIM

The aim of the present study was to evaluate the results of treatment and prognostic factors in adult patients with recurrent or refractory Ewing's sarcoma family tumors (ESFT).

PATIENTS AND METHODS

We retrospectively evaluated treatment outcomes of 54 consecutive patients with ESFT (aged 15 years or more) with complete medical records, who were treated with multimodal therapies after recurrence at the Istanbul University, Institute of Oncology.

RESULTS

The commonly used chemotherapy regimens at relapse were ifosfamide and etoposide (IE), ifosfamide and etoposide plus carboplatin (ICE), and oral etoposide. The median progression-free survival and overall survival for the entire group were 6.3 (95% confidence interval, 3.08-9.60) and 8.6 (95% confidence interval CI, 4.7-12.4) months, respectively. Multivariate analysis using a Cox proportional hazards model showed that non-IE/ICE chemotherapy regimens (p=0.003, hazard ratio=2.38) and the presence extrapulmonary metastases (p=0.045, hazard ratio=2.15) were associated with worse overall survival.

CONCLUSION

In primary refractory or relapsed ESFT, the presence of extrapulmonary metastases and treatment with salvage regimens other than ifosfamide and etoposide and/or carboplatin correlate with a poor prognosis.

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.