Allogeneic and autologous stem-cell transplantation in advanced Ewing tumors. An update after long-term follow-up from two centers of the European Intergroup study EICESS. Stem-Cell Transplant Programs at Düsseldorf University Medical Center, Germany and St. Anna Kinderspital, Vienna, Austria

Bad to the Bone: Emerging Approaches to Aggressive Bone Sarcomas

Bone sarcomas are rare heterogeneous tumors that affect patients of all ages including children, adolescent young adults, and older adults. They include many aggressive subtypes and patient groups with poor outcomes, poor access to clinical trials, and lack of defined standard therapeutic strategies. Conventional chondrosarcoma remains a surgical disease, with no defined role for cytotoxic therapy and no approved targeted systemic therapies. Here, we discuss promising novel targets and strategies undergoing evaluation in clinical trials. Multiagent chemotherapy has greatly improved outcomes for patients with Ewing sarcoma (ES) and osteosarcoma, but management of those with high-risk or recurrent disease remains challenging and controversial. We describe the impact of international collaborative trials, such as the rEECur study, that aim to define optimal treatment strategies for those with recurrent, refractory ES, and evidence for high-dose chemotherapy with stem-cell support. We also discuss current and emerging strategies for other small round cell sarcomas, such as CIC-rearranged, BCOR-rearranged tumors, and the evaluation of emerging novel therapeutics and trial designs that may offer a new paradigm to improve survival in these aggressive tumors with notoriously bad (to the bone) outcomes.

Challenges of Systemic Therapy Investigations for Bone Sarcomas

Bone sarcoma is a rare component of malignant solid tumors that accounts for only ~0.2% of malignancies. Bone sarcomas present various histological types, and genomic mutations differ markedly by the histological types. Although there are vast mutations in various bone sarcomas, most of them are non-actionable, and even potential targetable mutations that are actionable targets in other malignancies have not shown the appropriate responses in clinical trials for bone sarcomas. Investigations of new systemic therapy, including molecular targeted therapies for bone sarcomas, have thus not progressed like those for other solid tumors. Another problem is that high rates of pediatric/adolescent and young adult patients have bone sarcomas such as osteosarcoma, and patient recruitment for clinical trials (especially randomized trials) is challenging. For pediatric patients, evaluations of tolerability and appropriate dose modifications of new drugs are needed, as their findings could provide the threshold for investigating new drugs for bone sarcomas. To solve these problems, improvements in registry systems, real world data, and pediatric extrapolation have been attempted. We review the issues regarding targeted drug investigations for bone sarcomas, focusing on the current clinical evidence and efforts to resolve these issues.

High-dose chemotherapy followed by autologous haematopoietic cell transplantation for children, adolescents, and young adults with primary metastatic Ewing sarcoma

BACKGROUND

Ewing sarcomas are solid tumours of the bone and soft tissue, that usually affect children, adolescents, and young adults. The incidence is about three cases per million a year, with a peak incidence at 12 years of age. Metastatic disease is detected in about 20 % to 30% of people, and is typically found in the lungs, bone, bone marrow, or a combination of these. Presence of metastatic disease at diagnosis (primary metastatic disease) is the most important adverse prognostic factor, and is associated with a five-year survival lower than 30%. High-dose chemotherapy (HDC) followed by autologous haematopoietic cell transplantation (AHCT) is used in various solid tumours with unfavourable prognoses in children, adolescents, and young adults. It has also been used as rescue after multifocal radiation of metastases. The hypothesis is that HDC regimens may overcome the resistance to standard multidrug chemotherapy and improve survival rates.

OBJECTIVES

To assess the effects of high-dose chemotherapy with autologous haematopoietic cell transplantation compared with conventional chemotherapy in improving event-free survival, overall survival, quality-adjusted survival, and progression-free survival in children, adolescents, and young adults with primary metastatic Ewing sarcoma, and to determine the toxicity of the treatment.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, conference proceedings from major international cancer-related conferences, and ongoing trial registers until January 2020. We also searched reference lists of included articles and review articles.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) or (historical) controlled clinical trials (CCTs) comparing the effectiveness of HDC and AHCT with conventional chemotherapy for children, adolescents, and young adults (younger than 30 years at the date of diagnostic biopsy) with primary metastatic Ewing sarcoma.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane.

MAIN RESULTS

We identified one RCT, which investigated the effects of HDC with AHCT versus conventional chemotherapy with whole lung irradiation (WLI) in people with Ewing sarcoma metastasised to the lungs only at diagnosis. Only a selection of the participants were eligible for our review (N = 267: HDC with AHCT group N = 134; control group N = 133). There may be no difference in event-free survival between the two treatment groups (hazard ratio (HR) 0.83, 95% confidence interval (CI) 0.59 to 1.17; low-certainty evidence). We downgraded one level each because of study limitations and imprecision. Overall survival and toxicity were not reported separately for the participants eligible for this review, while quality-adjusted survival and progression-free survival were not reported at all. We did not identify any studies that addressed children, adolescents, and young adults with Ewing sarcoma with metastases to other locations.

AUTHORS' CONCLUSIONS

In people with Ewing sarcoma with primary metastases to locations other than the lungs, there is currently no evidence from RCTs or CCTs to determine the efficacy of HDC with AHCT compared to conventional chemotherapy. Based on low-certainty evidence from one study (267 participants), there may be no difference in event-free survival between children, adolescents, and young adults with primary pulmonary metastatic Ewing sarcoma who receive HDC with AHCT and those who receive conventional chemotherapy with WLI. Further high-quality research is needed. Results are anticipated for the EuroEwing 2008R3 study, in which the effects of HDC with treosulfan and melphalan followed by AHCT on survival, in people with Ewing sarcoma with metastatic disease to bone, other sites, or both were explored. Achieving high-quality studies in a selection of people with rare sarcoma requires long-term, multi-centre, international participant inclusion.

Clinical outcome of patients with recurrent or refractory localized Ewing's sarcoma family of tumors: A retrospective report from the Japan Ewing Sarcoma Study Group

BACKGROUND

Patients with Ewing's sarcoma family of tumors (ESFT) who experience relapse or progression have a poor prognosis.

AIM

This study aimed to identify the prognostic and therapeutic factors affecting overall survival (OS) of patients with recurrent or refractory localized ESFT.

METHODS AND RESULTS

Thirty-eight patients with localized ESFT who experienced first relapse or progression between 2000 and 2018 were retrospectively reviewed. The 5-year OS rate of the entire cohort was 48.3% (95% confidence interval, 29.9%-64.5%). Multivariate analysis of OS identified time to relapse or progression, but not stem cell transplantation (SCT), as the sole independent risk factor (hazard ratio, 35.8; P = .002). Among 31 patients who received salvage chemotherapy before local treatment, 21 received chemotherapy regimens that are not conventionally used for newly diagnosed ESFT. The objective response rate to first-line salvage chemotherapy was 55.2% in the 29 evaluable patients. Time to relapse or progression was significantly associated with response to first-line salvage chemotherapy (P = .006).

CONCLUSIONS

The present study fails to demonstrate significant clinical benefit of SCT for recurrent or refractory localized ESFT. Recently established chemotherapy regimens may increase the survival rate of patients with recurrent or refractory localized ESFT while attenuating the beneficial effect of SCT.

No difference in survival after HLA mismatched versus HLA matched allogeneic stem cell transplantation in Ewing sarcoma patients with advanced disease

Patients with advanced Ewing sarcoma (AES) carry a poor prognosis. Retrospectively, we analyzed 66 AES patients treated with allogeneic stem cell transplantation (allo-SCT) receiving HLA-mismatched (group A, n = 39) versus HLA-matched grafts (group B, n = 27). Median age at diagnosis was 13 years, and 15 years (range 3-49 years) at allo-SCT. The two groups did not differ statistically in distribution of gender, age, remission status/number of relapses at allo-SCT, or risk stratum. 9/39 (23%) group A versus 2/27 (7%) group B patients developed severe acute graft versus host disease (GvHD). Of patients alive at day 100, 7/34 (21%) group A versus 9/19 (47%) group B patients had developed chronic GvHD. In group A, 33/39 (85%) versus 20/27 (74%) group B patients died of disease and 1/39 (3%) versus 1/27 (4%) patients died of complications, respectively. Altogether 12/66 (18%) patients survived in CR. Median EFS 24 months after allo-SCT was 20% in both groups, median OS was 27% (group A) versus 17% (group B), respectively. There was no difference in EFS and OS in AES patients transplanted with HLA-mismatched versus HLA-matched graft in univariate and multivariate analyses. In this analysis, CR at allo-SCT is a condition for survival (p < 0.02).

Antiemetic Prophylaxis with Fosaprepitant and 5-HT3-Receptor Antagonists in Pediatric Patients Undergoing Autologous Hematopoietic Stem Cell Transplantation

Background

High-dose myeloablative conditioning prior to autologous hematopoietic stem cell transplantation (autoHSCT) in pediatric patients is usually highly emetogenic. The antiemetic neurokinin-1 receptor antagonist fosaprepitant was safe and effective in children receiving highly emetogenic chemotherapy. Data on fosaprepitant during autoHSCT in children are currently not available.

Methods

A total of 35 consecutive pediatric patients, who received an antiemetic prophylaxis with fosaprepitant (4 mg/kg; single dose, max. 1 x 150 mg/kg BW) and ondansetron (24-hours continuous infusion; 8–32 mg/24h) or granisetron (2 x 40 µg/kg∙d⁻¹) during highly emetogenic conditioning chemotherapy before autoHSCT were retrospectively analyzed, and their results were compared with a control group comprising 35 consecutive pediatric patients, who received granisetron or ondansetron only. The antiemetic efficacy and the safety of the two prophylaxis regimens were compared with respect to three time periods after the first chemotherapy administration (0–24h, >24–120h, >120–240h).

Results

Clinical adverse events and clinically relevant increases/decreases of laboratory markers were similarly low and did not significantly differ between the two study groups (p>0.05). The registered number of vomiting events was significantly higher in the control group in the time periods of 0–24h (64 vs 22 events; p<0.01), >24–120h (135 vs 78 events; p<0.0001), >120–240h (268 vs 105 events; p<0.0001), and the whole observation period 0–240h (467 vs 205 events; p<0.0001). The percentage of patients experiencing vomiting was higher in the control group during the time period of >24–120h (100% vs 74.3%) but not the other analyzed time periods (p>0.05).

Conclusion

The fosaprepitant-based antiemetic prophylaxis was safe, well tolerated and significantly reduced vomiting in children undergoing highly emetogenic chemotherapy prior to autoHSCT. Prospective randomized trials are necessary to confirm these results.

MHC Class I-Restricted TCR-Transgenic CD4+ T Cells Against STEAP1 Mediate Local Tumor Control of Ewing Sarcoma In Vivo

In this study we report the functional comparison of T cell receptor (TCR)-engineered major histocompatibility complex (MHC) class I-restricted CD4⁺ versus CD8⁺ T cells targeting a peptide from six transmembrane epithelial antigen of the prostate 1 (STEAP1) in the context of HLA-A*02:01. STEAP1 is a tumor-associated antigen, which is overexpressed in many cancers, including Ewing sarcoma (EwS). Based on previous observations, we postulated strong antitumor potential of tumor-redirected CD4⁺ T cells transduced with an HLA class I-restricted TCR against a STEAP1-derived peptide. We compared CD4⁺ T cell populations to their CD8⁺ counterparts in vitro using impedance-based xCELLigence and cytokine/granzyme release assays. We further compared antitumor activity of STEAP¹³⁰-TCR transgenic (tg) CD4⁺ versus CD8⁺ T cells in tumor-bearing xenografted Rag2^-/-gc^-/- mice. TCR tgCD4⁺ T cells showed increased cytotoxic features over time with similar functional avidity compared to tgCD8⁺ cells after 5-6 weeks of culture. In vivo, local tumor control was equal. Assessing metastatic organotropism of intraveniously (i.v.) injected tumors, only tgCD8⁺ cells were associated with reduced metastases. In this analysis, EwS-redirected tgCD4⁺ T cells contribute to local tumor control, but fail to control metastatic outgrowth in a model of xenografted EwS.

Bone marrow examination in patients with Ewing sarcoma/peripheral primitive neuroectodermal tumor without metastasis based on 18F-fluorodeoxyglucose positron emission tomography/computed tomography

Ewing sarcoma/peripheral primitive neuroectodermal tumor (ES/PNET) is an aggressive bone tumor. Bone marrow aspiration and biopsy (BMAB) has been recognized as the gold standard for assessing bone marrow status. While the latest guideline suggests the need to omit bone marrow aspiration in patients with no findings on ¹⁸F-fluorodeoxyglucose positron emission tomography (¹⁸F-FDG PET) based on one retrospective report, there is no study using ¹⁸F-FDG PET/computed tomography (CT). We retrospectively reviewed 26 consecutive, previously untreated, ES/PNET patients. We compare the results of bone marrow aspiration and biopsy (BMAB) and those of ¹⁸F-FDG PET/CT in ES/PNET patients. All of the 21 patients without metastases on ¹⁸F-FDG PET/CT had negative BMAB. The sensitivity of bone marrow involvement in bone metastases positive patients on ¹⁸F-FDG PET/CT was 75% (3/4), and the specificity was 100% (22/22). In addition to the metastatic findings on ¹⁸F-FDG PET/CT, tumor diameter, lactate dehydrogenase level at diagnosis, and the presence or absence of bone metastasis were factors related to bone marrow involvement. It may be a reasonable option to omit BMAB in ES/PNET patients with no distant metastasis based on ¹⁸F-FDG PET/CT findings.

Natural Killer Cells: Development, Maturation, and Clinical Utilization

Natural killer (NK) cells are the predominant innate lymphocyte subsets that mediate anti-tumor and anti-viral responses, and therefore possess promising clinical utilization. NK cells do not express polymorphic clonotypic receptors and utilize inhibitory receptors (killer immunoglobulin-like receptor and Ly49) to develop, mature, and recognize “self” from “non-self.” The essential roles of common gamma cytokines such as interleukin (IL)-2, IL-7, and IL-15 in the commitment and development of NK cells are well established. However, the critical functions of pro-inflammatory cytokines IL-12, IL-18, IL-27, and IL-35 in the transcriptional-priming of NK cells are only starting to emerge. Recent studies have highlighted multiple shared characteristics between NK cells the adaptive immune lymphocytes. NK cells utilize unique signaling pathways that offer exclusive ways to genetically manipulate to improve their effector functions. Here, we summarize the recent advances made in the understanding of how NK cells develop, mature, and their potential translational use in the clinic.

Impact of Pathological Fractures on the Prognosis of Primary Malignant Bone Sarcoma in Children and Adults: A Single-Center Retrospective Study of 205 Patients

BACKGROUND

The purpose of this study was to investigate whether pathological fractures (PF) influence the prognosis of patients with osteosarcoma (OS) or Ewing tumor (ET) regarding 5-year survival, occurrence of metastases, and local recurrence.

METHODS

We retrospectively analyzed 205 patients with metastatic and nonmetastatic OS or ET. Survival analysis was performed for all patients and differentiated for patients with OS (n = 127) and ET (n = 78) as well as for adults (n = 101) and children (n = 104).

RESULTS

Patients with PF showed survival rates of 64% compared to 83% for those without PF (p = 0.023). Local recurrence occurred in 7% of the patients without and in 24% of those with PF (p = 0.023). In patients with ET and in children, survival analysis showed no significant difference between patients with and without PF in survival and local recurrence rates. In patients with OS, survival rate decreased from 83 to 59% (p = 0.024) and local recurrence rate increased from 13 to 30% (p = 0.042). In adults, survival rate decreased from 78 to 51% (p = 0.004) and local recurrence rate increased from 13 to 42% (p < 0.001). In multivariate analysis, age and PF were associated with inferior survival.

CONCLUSION

This study suggests that the occurrence of PF has a negative impact on survival and implicates an increased risk of local recurrence. In children and in patients with ET, PF did not have a prognostic impact.

Bone marrow involvement identifies a subgroup of advanced Ewing sarcoma patients with fatal outcome irrespective of therapy in contrast to curable patients with multiple bone metastases but unaffected marrow

Purpose

Advanced Ewing sarcomas have poor prognosis. They are defined by early relapse (<24 months after diagnosis) and/or by metastasis to multiple bones or bone marrow (BM). We analyzed risk factors, toxicity and survival in advanced Ewing sarcoma patients treated with the MetaEICESS vs. EICESS92 protocols.

Design

Of 44 patients, 18 patients were enrolled into two subsequent MetaEICESS protocols between 1992 and 2014, and compared to outcomes of 26 advanced Ewing sarcoma patients treated with EICESS 1992 between 1992 and 1996. MetaEICESS 1992 consisted of induction chemotherapy, whole body imaging directed radiotherapy to the primary tumor and metastases, tandem high-dose chemotherapy and autologous rescue. In MetaEICESS 2007 this treatment was complemented by allogeneic stem cell transplantation. EICESS 1992 comprised induction chemotherapy, local therapy to the primary tumor only followed by consolidation chemotherapy.

Results

In MetaEICESS 8/18 patients survived in complete remission vs. 2/26 in EICESS 1992 (p<0.05). Survival did not differ between MetaEICESS 2007 and MetaEICESS 1992. Three MetaEICESS patients died of complications, all in MetaEICESS 1992. After exclusion of patients succumbing to treatment related complications (n=3), 7/10 patients survived without BM involvement, in contrast to 0/5 patients with BM involvement. This was confirmed in a multivariate analysis. There was no correlation between BM involvement and the number of metastases at diagnosis.

Conclusion

The MetaEICESS protocols yield long-term disease-free survival in patients with advanced Ewing sarcoma. Allogeneic stem cell transplantation was not associated with increased death of complications. Bone marrow involvement is a risk factor distinct from multiple bone metastases.

Human HLA-A*02:01/CHM1+ allo-restricted T cell receptor transgenic CD8+ T cells specifically inhibit Ewing sarcoma growth in vitro and in vivo

The endochondral bone protein Chondromodulin-I (CHM1) provides oncogene addiction in Ewing sarcoma (ES). We pre-clinically tested the targetability of CHM1 by TCR transgenic, allo-restricted, peptide specific T cells to treat ES. We previously generated allo-restricted wildtype CD8+ T cells directed against the ES specific antigen CHM1319 causing specific responses against ES. However, utilization of these cells in current therapy protocols is hampered due to high complexity in production, relatively low cell numbers, and rapid T cell exhaustion.In order to provide off-the-shelf products in the future, we successfully generated HLA-A*02:01-restricted T cell receptor (TCR) transgenic T cells directed against CHM1319 by retroviral transduction.After short-term expansion a 100% purified CHM1319-TCR-transgenic T cell population expressed a CD62L+/CD45RO and CD62L+/CD45RA+ phenotype. These cells displayed specific in vitro IFNg and granzyme B release in co-culture with HLA-A*02:01+ ES cell lines expressing CHM1. When co-injected with ES cells in Rag2-/-É£c-/- mice, CHM1-specific TCR-transgenic T cells significantly inhibited the formation of lung and liver metastases in contrast to control mice. Lungs and livers of representative mice displayed CD8+ T cell infiltration in the presence (control group treated with unspecific T cells) and in the absence (study group) of metastatic disease, respectively. Furthermore, mice receiving unspecific T cells showed signs of graft-versus-host-disease in contrast to all mice, receiving CHM1319-TCR-transgenic T cells.CHM1319 specific TCR-transgenic T cells were successfully generated causing anti-ES responses in vitro and in vivo. In the future, CHM1319-TCR-transgenic T cells may control minimal residual disease rendering donor lymphocyte infusions more efficacious and less toxic.

Acute Lymphoblastic Leukemia as Secondary Malignancy in a Case of Ewing's Sarcoma on Treatment

The survival of Ewing's sarcoma (ES) has improved due to advances in both local and systemic therapy. This has given rise to an increased detection of second malignant neoplasms which can be in the form of solid tumors and hematological malignancies. The most common hematological malignancies are acute myeloid leukemia/myelodysplastic syndrome. Acute lymphoblastic leukemia (ALL) is relatively uncommon in occurrence in this setting. Furthermore, the average refractory period for hematological malignancies varies from 3 to 5 years. We report a case of a young female who developed ALL while on adjuvant therapy for ES.

Neutropenia during the First Cycle of Induction Chemotherapy Is Prognostic for Poor Survival in Locoregionally Advanced Nasopharyngeal Carcinoma: A Real-World Study in an Endemic Area

Purpose

The purpose of this study was to investigate the effect of neutropenia during the first cycle of induction chemotherapy (IC-1) on survival in locoregionally advanced nasopharyngeal carcinoma (LANPC).

Materials and Methods

Eligible patients (n=545) with LANPC receiving IC+concurrent chemoradiotherapy were included. Based on nadir neutrophil afterIC-1, all patientswere categorized into three groups: no/grade 1-2/grade 3-4 neutropenia. Five-year overall survival (OS) and disease-free survival (DFS) were compared between groups and subgroups stratified by IC regimen. We also explored the occurrence of IC-1-induced myelosuppression events and the minimal value of post-treatment neutrophil-to-lymphocyte ratio (post-NLRmin). Univariate/multivariate analyses were performed to investigate the effect of IC-1-induced neutropenia, timing of neutropenia, number of myelosuppression events, and high post-NLRmin on OS/DFS.

Results

Grade 1-2/grade 3-4 neutropeniawere associatedwith poorer OS/DFS than no neutropenia (all p &lt; 0.05); OS/DFS were not significantly different between patients experiencing grade 1-2 vs. 3-4 neutropenia. Neutropenia had no significant effect on OS/DFS in patients receiving docetaxel-cisplatin-5-fluorouracil (TPF). Grade 1-2 (grade 3-4) neutropenia negatively influenced OS/DFS in patients receiving cisplatin-5-fluorouracil (PF) (PF and docetaxel-cisplatin [TP]; all p &lt; 0.05). Neutropenia, two/three myelosuppression events, and high post-NLRmin (≥ 1.33) was most frequent on days 5-10, second and third week of IC-1, respectively. After adjustment for covariates, IC-1-induced neutropenia, two/three myelosuppression events, and post-NLRmin ≥ 1.33were validated as negative predictors of OS/DFS (all p &lt; 0.05); timing of neutropenia had no significant effect.

Conclusion

Occurrence of neutropenia, number of myelosuppression events, and high post-NLRmin during PF/TP IC-1 have prognostic value for poor survival in LANPC.

Pappalysin-1 T cell receptor transgenic allo-restricted T cells kill Ewing sarcoma in vitro and in vivo

Pregnancy-associated plasma protein-A (PAPPA), also known as pappalysin, is a member of the insulin-like growth factor (IGF) family. PAPPA acts as a protease, cleaving IGF inhibitors, i.e., IGF binding proteins (IGFBPs), thereby setting free IGFs. The insulin/IGF-axis is involved in cancer in general and in Ewing sarcoma (ES) in particular. ES is a highly malignant bone tumor characterized by early metastatic spread. PAPPA is associated with various cancers. It is overexpressed and required for proliferation in ES. PAPPA also stimulates normal bone growth. We isolated HLA-A*02:01⁺/peptide-restricted T cells from A*02:01⁻ healthy donors directed against PAPPA, generated by priming with A*02:01⁺ PAPPA peptide loaded dendritic cells. After TCR identification, retrovirally TCR transduced CD8⁺ T cells were assessed for their in vitro specificity and in vivo efficacy in human ES bearing Rag2^−/−γc^−/− mice. Engraftment in mice and tumor infiltration of TCR transgenic T cells in the mice was evaluated. The TCR transgenic T cell clone PAPPA-2G6 demonstrated specific reactivity toward HLA-A*02:01⁺/PAPPA⁺ ES cell lines. We furthermore detected circulating TCR transgenic T cells in the blood in Rag2^−/−γc^−/− mice and in vivo engraftment in bone marrow. Tumor growth in mice with xenografted ES was significantly reduced after treatment with PAPPA-2G6 TCR transgenic T cells in contrast to controls. Tumors of treated mice revealed tumor-infiltrating PAPPA-2G6 TCR transgenic T cells. In summary, we demonstrate that PAPPA is a first-rate target for TCR-based immunotherapy of ES.

Transgenic antigen-specific, HLA-A*02:01-allo-restricted cytotoxic T cells recognize tumor-associated target antigen STEAP1 with high specificity

Pediatric cancers, including Ewing sarcoma (ES), are only weakly immunogenic and the tumor-patients' immune system often is devoid of effector T cells for tumor elimination. Based on expression profiling technology, targetable tumor-associated antigens (TAA) are identified and exploited for engineered T-cell therapy. Here, the specific recognition and lytic potential of transgenic allo-restricted CD8(+) T cells, directed against the ES-associated antigen 6-transmembrane epithelial antigen of the prostate 1 (STEAP1), was examined. Following repetitive STEAP1(130) peptide-driven stimulations with HLA-A*02:01(+) dendritic cells (DC), allo-restricted HLA-A*02:01(-) CD8(+) T cells were sorted with HLA-A*02:01/peptide multimers and expanded by limiting dilution. After functional analysis of suitable T cell clones via ELISpot, flow cytometry and xCELLigence assay, T cell receptors' (TCR) α- and β-chains were identified, cloned into retroviral vectors, codon optimized, transfected into HLA-A*02:01(-) primary T cell populations and tested again for specificity and lytic capacity in vitro and in a Rag2(-/-)γc(-/-) mouse model. Initially generated transgenic T cells specifically recognized STEAP1(130)-pulsed or transfected cells in the context of HLA-A*02:01 with minimal cross-reactivity as determined by specific interferon-γ (IFNγ) release, lysed cells and inhibited growth of HLA-A*02:01(+) ES lines more effectively than HLA-A*02:01(-) ES lines. In vivo tumor growth was inhibited more effectively with transgenic STEAP1(130)-specific T cells than with unspecific T cells. Our results identify TCRs capable of recognizing and inhibiting growth of STEAP1-expressing HLA-A*02:01(+) ES cells in vitro and in vivo in a highly restricted manner. As STEAP1 is overexpressed in a wide variety of cancers, we anticipate these STEAP1-specific TCRs to be potentially useful for immunotherapy of other STEAP1-expressing tumors.

Immunostimulation by OX40 Ligand Transgenic Ewing Sarcoma Cells

Interleukin-2 (IL-2) transgenic Ewing sarcoma cells can induce tumor specific T and NK cell responses and reduce tumor growth in vivo and in vitro. Nevertheless, the efficiency of this stimulation is not high enough to inhibit tumor growth completely. In addition to recognition of the cognate antigen, optimal T-cell stimulation requires signals from so-called co-stimulatory molecules. Several members of the tumor necrosis factor superfamily have been identified as co-stimulatory molecules that can augment antitumor immune responses. OX40 (CD134) and OX40 ligand (OX40L = CD252; also known as tumor necrosis factor ligand family member 4) is one example of such receptor/ligand pair with co-stimulatory function. In the present investigation, we generated OX40L transgenic Ewing sarcoma cells and tested their immunostimulatory activity in vitro. OX40L transgenic Ewing sarcoma cells showed preserved expression of Ewing sarcoma-associated (anti)gens including lipase member I, cyclin D1 (CCND1), cytochrome P450 family member 26B1 (CYP26B1), and the Ewing sarcoma breakpoint region 1-friend leukemia virus integration 1 (EWSR1-FLI1) oncogene. OX40L-expressing tumor cells showed a trend for enhanced immune stimulation against Ewing sarcoma cells in combination with IL-2 and stimulation of CD137. Our data suggest that inclusion of the OX40/OX40L pathway of co-stimulation might improve immunotherapy strategies for the treatment of Ewing sarcoma.

High-dose Thiotepa as Consolidation Therapy With Autologous Hematopoietic Stem Cell Transplantation for High-risk Ewing Family Tumors: Single-institution Experience

High-dose therapy (HDTx) with autologous stem cell rescue has been widely applied in very-poor-risk pediatric solid tumors. Promising data have become available with the use of high-dose busulfan, whereas high-dose (HD) thiotepa is less commonly used. We report retrospectively our single-institution experience from 1986 to 2012 of single and tandem HDTx with special emphasis on HD-thiotepa as the backbone of HD regimen in Ewing family tumors, including all 24 patients in the Helsinki University Hospital referral area in population-based fashion (Ewing sarcoma 9, Askin tumor 9, peripheral neuroectodermal tumor 6). The 10-year overall survival for the entire cohort was 0.73±0.01. Thirteen out of the 24 underwent HDTx (10 single, 3 tandem). The HDTx regimen consisted of HD-thiotepa (900 mg/m), VP16, and carboplatin. Additional HD-melphalan and total body irradiation were used in the tandem regimens. There was no toxic mortality. The 5-year event-free survival was 0.73±0.16 for high-risk cases transplanted in 1CR. In the relapse group, 1 out of the 3 survived. Radiotherapy to axial sites was given safely in combination with HD-thiotepa in all 3 patients. Thiotepa-based HDTx approach resulted in an encouraging outcome without toxic mortality for high-risk patients. HD-thiotepa merits further studies in larger controlled series.

Advances in therapy for pediatric sarcomas

Pediatric sarcomas are relatively rare malignancies individually. As a group they are typically approached with combination chemotherapies in addition to local control. Fortunately, these malignancies have been approached through careful clinical trial collaboration to define risk groups and appropriately deliver local control measures and systemic therapies. Although local disease is typically approached with curative intent, therapy typically lasts over 6 months and has significant associated morbidities. It is more difficult to cure metastatic disease or induce sustained remissions. In this article, we discuss recent advances in the understanding of the disease process and highlight recent and future cooperative group trials in osteosarcoma, Ewing sarcoma, rhabdomyosarcoma, nonrhabdomyosarcoma soft tissue sarcomas, and desmoid tumor as well as discuss promising therapeutic approaches such as epigenetics and immunotherapy.

The value of high-dose chemotherapy in patients with first relapsed Ewing sarcoma

BACKGROUND

Prognosis of patients with relapsed Ewing sarcoma (ES) is poor. The 5-year overall survival (OS) is 13%. We analyzed high-dose chemotherapy (HDtx) versus conventional chemotherapy (CHtx) in patients with relapsed ES.

PROCEDURE

Data from 239 patients with first relapse, registered during 2000-2011 in the ES relapse registry of the Cooperative Ewing Sarcoma Study Group (CESS) were analyzed.

RESULTS

Of 239 patients, 200 received various non-HDtx second-line CHtx regimens. Seventy-three patients had additional HDtx followed by autologous stem cell rescue. The 2-year event-free survival (EFS) was 10% (SE = 0.02) in patients treated without HDtx and 45% (SE = 0.09) in patients treated with HDtx. In a second step, we focused on those patients who achieved complete remission (CR) or partial remission (PR) after four to six cycles of conventional second-line CHtx. Here, the 2-year EFS was 31% (SE = 0.08) without additional HDtx and 44% (SE = 0.09) with additional HDtx. In addition, multivariate regression analysis indicates absence of HDtx treatment, with a Hazard ratio (HR) of 2.90 (95% CI 1.41-6.0), and early relapse, with a HR of 4.76 (95% CI 2.31-9.78), as independent prognostic factors for EFS.

CONCLUSION

Additional HDtx may contribute to further reduce the risk of further events in patients who respond to conventional second-line CHtx.

Autologous hematopoietic stem cell transplantation for pediatric solid tumors

While advances in the treatment of pediatric cancers have increased cure rates, children with metastatic or recurrent solid tumors have a dismal prognosis despite initial transient responses to therapy. Autologous hematopoietic stem cell transplantation takes advantage of the steep dose-response relationship observed with many chemotherapeutic agents. While clearly demonstrated to improve outcomes in patients with metastatic neuroblastoma, autologous hematopoietic stem cell transplantation is also frequently used to treat patients with other high-risk diseases such as Ewing sarcoma, osteosarcoma, rhabdomyosarcoma, Wilms' tumor, retinoblastoma, germ cell tumors, lymphomas and brain tumors. Most published experience consists of retrospective, single-arm studies; randomized clinical trials are lacking, due in part to the rarity of pediatric cancers treatable by autologous hematopoietic stem cell transplantation. These published literature demonstrate that autologous hematopoietic stem cell transplantation results in most cases in equivalent or superior outcomes when compared with conventional therapies. However, patient heterogeneity, patient selection, graft characteristics and processing and the varied conditioning regimens are additional factors to consider. Since the inception of autologous hematopoietic stem cell transplantation, regimen-related toxicity has markedly decreased and the vast majority of treatment failures are now due to disease recurrence. Prospective clinical trials are needed to identify specific high-risk patient populations, with randomization (when possible) to compare outcomes of patients undergoing autologous hematopoietic stem cell transplantation with those receiving standard therapy. In addition, investigators need to better define the role of autologous hematopoietic stem cell transplantation in these solid tumors, particularly in combination with other therapeutic modalities such as immunotherapy and novel cell processing methodologies.

Characterization and drug resistance patterns of Ewing's sarcoma family tumor cell lines

Despite intensive treatment with chemotherapy, radiotherapy and surgery, over 70% of patients with metastatic Ewing's Sarcoma Family of Tumors (EFT) will die of their disease. We hypothesize that properly characterized laboratory models reflecting the drug resistance of clinical tumors will facilitate the application of new therapeutic agents to EFT. To determine resistance patterns, we studied newly established EFT cell lines derived from different points in therapy: two established at diagnosis (CHLA-9, CHLA-32), two after chemotherapy and progressive disease (CHLA-10, CHLA-25), and two at relapse after myeloablative therapy and autologous bone marrow transplantation (post-ABMT) (CHLA-258, COG-E-352). The new lines were compared to widely studied EFT lines TC-71, TC-32, SK-N-MC, and A-673. These lines were extensively characterized with regard to identity (short tandem repeat (STR) analysis), p53, p16/14 status, and EWS/ETS breakpoint and target gene expression profile. The DIMSCAN cytotoxicity assay was used to assess in vitro drug sensitivity to standard chemotherapy agents. No association was found between drug resistance and the expression of EWS/ETS regulated genes in the EFT cell lines. No consistent association was observed between drug sensitivity and p53 functionality or between drug sensitivity and p16/14 functionality across the cell lines. Exposure to chemotherapy prior to cell line initiation correlated with drug resistance of EFT cell lines in 5/8 tested agents at clinically achievable concentrations (CAC) or the lower tested concentration (LTC): (cyclophosphamide (as 4-HC) and doxorubicin at CAC, etoposide, irinotecan (as SN-38) and melphalan at LTC; P<0.1 for one agent, and P<0.05 for four agents. This panel of well-characterized drug-sensitive and drug-resistant cell lines will facilitate in vitro preclinical testing of new agents for EFT.

Immunotherapy of sarcomas

PURPOSE OF REVIEW

To describe the current advances in immunotherapy and how they can be applied to sarcoma. This review will discuss the recent literature and selected clinical trials. Evidence supporting treatment with immunotherapy alone in sarcoma will be reviewed, as will the potential incorporation of immunotherapy into treatment for sarcoma.

RECENT FINDINGS

Sarcoma, cancer of the connective tissues, frequently strikes young people, comprising a large percentage of cancer in children and young adults, but may occur at any age. Although molecularly targeted inhibitors are of great interest in treating sarcoma patients, immunotherapy is emerging as a plausible therapeutic modality because of the recent advances in other cancer types that may be translated to sarcoma. The licensing of ipilimumab and sipuleucel-T for cancer, and the remarkable success of immunotherapy for some childhood cancers, suggest a role for immunotherapy in the treatment of tumors like sarcoma.

SUMMARY

Sarcoma is a disease for which new treatments are needed. Immunotherapies have different mechanisms of action from most current therapies and could work in concert with them. Recent advances in sarcoma biology and cancer immunotherapy suggest that our knowledge of the immune system has reached the point where it can be used to augment both targeted and multimodality therapy for sarcoma.

Allogeneic stem cell transplantation for patients with advanced rhabdomyosarcoma: a retrospective assessment

BACKGROUND

Allogeneic haematopoietic stem cell transplantation (allo-SCT) may provide donor cytotoxic T cell-/NK cell-mediated disease control in patients with rhabdomyosarcoma (RMS). However, little is known about the prevalence of graft-vs-RMS effects and only a few case experiences have been reported.

METHODS

We evaluated allo-SCT outcomes of 30 European Group for Blood and Marrow Transplantation (EBMT)-registered patients with advanced RMS regarding toxicity, progression-free survival (PFS) and overall survival (OS) after allo-SCT. Twenty patients were conditioned with reduced intensity and ten with high-dose chemotherapy. Twenty-three patients were transplanted with HLA-matched and seven with HLA-mismatched grafts. Three patients additionally received donor lymphocyte infusions (DLIs). Median follow-up was 9 months.

RESULTS

Three-year OS was 20% (s.e.±8%) with a median survival time of 12 months. Cumulative risk of progression was 67% (s.e.±10%) and 11% (s.e.±6%) for death of complications. Thirteen patients developed acute graft-vs-host disease (GvHD) and five developed chronic GvHD. Eighteen patients died of disease and four of complications. Eight patients survived in complete remission (CR) (median: 44 months). No patients with residual disease before allo-SCT were converted to CR.

CONCLUSION

The use of allo-SCT in patients with advanced RMS is currently experimental. In a subset of patients, it may constitute a valuable approach for consolidating CR, but this needs to be validated in prospective trials.

The vigor of defense against non-self: potential superiority of allorestricted T cells in immunotherapy of cancer?

Men and sharks are both jawed vertebrates at the top of the food chain. Sharks are the first extant to develop adaptive immunity preserved to man throughout jawed vertebrates. We hypothesize here, that T cell receptor/major histocompatibility complex (TCR/MHC) interactions developed as the defense mechanism of carnivors against takeover by their victims’ cells derived pathogens. Germline encoded TCR segments have been conserved in evolution, providing the MHC bias of TCR. Ancestor genes of MHC polymorphisms may have first developed as a mating preference system, that later in evolution provided host immune responses destroying infectious non-self, yet maintaining tolerance to self. Pathogens may thus have simultaneously selected for alloimmunity. Allorejection has been observed in sharks and men. Cannibalism is a common ecological interaction in the animal kingdom, especially prevalent in aquatic communities; it favors selection of intraspecies allo responses for defense of self integrity. Alloreactive T cells do not undergo negative selection of strong TCR/MHC interactions; thus, they react stronger than self-MHC recognizing T cells. High levels of genetic diversity at MHC genes play a critical role in protecting populations of vertebrate species from contagious cells displaying stemness and homing features, including cancer cells. Recognition of self-MHC fails especially in diseases, which predominantly arise with age and after the peak of reproduction, e.g., cancer. So far, the treatment of malignant disease with autologous T cells has widely failed. Allorecognition constitutes an extremely powerful mechanism in evolution, which may be employed in immunotherapy of cancer by MHC-disparate, e.g., haploidentical transplantation and consecutive treatment with T cells from the donor parents recognizing tumor selective peptides presented by the non-inherited haplotype on the tumor.

Does Radiotherapy Have Curative Potential in Metastatic Patients? The Concept of Local Therapy in Oligometastatic Breast Cancer

In 1995, Hellmann and Weichselbaum defined for the first time the term oligometastases which is used to describe limited metastasis with a maximum of 3-4 clinically detectable metastases. It is assumed that these patients have a better prognosis and that local treatment of the metastases plays a significant part in the further development of the disease. Therefore, these patients could benefit from a curative local therapy of the manifested metastases. Local therapy measures include mainly radiotherapeutic methods alongside invasive ablative processes, such as surgical resection and radiofrequency ablation. Patients subjected to radiation therapy benefit especially from the usage of modern precision technology as it reduces the radiation exposure to the normal tissue, and because short radiation sessions with escalating doses are possible (e.g. radiation surgery, image-assisted radiation therapy, stereotactic radiation). Initial clinical studies show very good local tumor control rates which are on a par with resection and ablative methods, but with very few side effects and risks. This article summarizes the integration of the concept of oligometastases in the radiotherapy of limited metastatic breast cancer.

Reduced-intensity allogeneic stem cell transplantation in children and young adults with ultrahigh-risk pediatric sarcomas

Some subsets of pediatric sarcoma patients have very poor survival rates. We sought to determine the feasibility and efficacy of allogeneic hematopoietic stem cell transplantation (alloHSCT) in pediatric sarcoma populations with <25% predicted overall survival (OS). Patients with ultrahigh-risk Ewing's sarcoma family of tumors (ESFT), alveolar rhabdomyosarcoma, or desmoplastic small round cell tumors received EPOCH-fludarabine induction, a cyclophosphamide/fludarabine/melphalan preparative regimen, and HLA matched related peripheral blood stem cells. Thirty patients enrolled; 7 did not undergo alloHSCT because of progressive disease with diminishing performance status during induction. All 23 alloHSCT recipients experienced rapid full-donor engraftment, with no peritransplantation mortality. Five of 23 alloHSCT recipients (22%) remain alive (OS of 30% by Kaplan-Meier analysis at 3 years), including 3 of 7 (42%) transplanted without overt disease (median survival 14.5 versus 29.0 months from alloHSCT for patients transplanted with versus without overt disease, respectively). Among the 28 patients who progressed on the study, the median survival from date of progression was 1.9 months for the 7 who did not receive a transplant compared with 11.4 months for the 21 transplanted (P = .0003). We found prolonged survival after posttransplantation progression with several patients exhibiting indolent tumor growth. We also saw several patients with enhanced antitumor effects from posttransplantation chemotherapy (objective response to pretransplantation EPOCH-F was 24% versus 67% to posttransplantation EOCH); however, this was associated with increased toxicity. This largest reported series of alloHSCT in sarcomas demonstrates that alloHSCT is safe in this population, and that patients undergoing alloHSCT without overt disease show higher survival rates than reported using standard therapies. Enhanced chemo- and radiosensitivity of tumors and normal tissues was observed posttransplantation.

High-dose chemotherapy and stem cell rescue for high-risk Ewing's family of tumors

The prognosis for high-risk Ewing's tumors has been improved by multimodal radiation and chemotherapy. Ewing's family of tumors requires risk-adapted treatment. Risk stratification is dependent on stage, tumor localization and volume, and the pattern of disease spread at the time of diagnosis and the time of relapse. The concepts for high-dose therapy followed by hematopoietic cell transplantation in Ewing's family of tumors are based on dose-response and dose-intensity relationships. This article will discuss the use of high-dose therapy followed by hematopoietic cell transplantation, focusing on recent progress with respect to agent combinations, dose and outcomes of therapy.

Specific recognition and inhibition of Ewing tumour growth by antigen-specific allo-restricted cytotoxic T cells

Background:

The development of a successful immunotherapy is hampered by an ineffective T-cell repertoire against tumour antigens and the inability of the patient's immune system to overcome tolerance-inducing mechanisms. Here, we test the specific recognition and lytical potential of allo-restricted CD8⁺ T cells against Ewing tumour (ET) associated antigens Enhancer of Zeste, Drosophila Homolog 2 (EZH2), and Chondromodulin-I (CHM1) identified through previous microarray analysis.

Methods:

Following repetitive CHM1³¹⁹ (VIMPCSWWV) and EZH2⁶⁶⁶ (YMCSFLFNL) peptide-driven stimulations with HLA-A^*0201⁺ dendritic cells (DC), allo-restricted HLA-A^*0201⁻ CD8⁺ T cells were stained with HLA-A^*0201/peptide multimers, sorted and expanded by limiting dilution.

Results:

Expanded T cells specifically recognised peptide-pulsed target cells or antigen-transfected cells in the context of HLA-A^*0201 and killed HLA-A^*0201⁺ ET lines expressing the antigen while HLA-A^*0201^– ET lines were not affected. Furthermore, adoptively transferred T cells caused significant ET growth delay in Rag2^−/−γ_C^−/− mice. Within this context, we identified the CHM1³¹⁹ peptide as a new candidate target antigen for ET immunotherapy.

Conclusion:

These results clearly identify the ET-derived antigens, EZH2⁶⁶⁶ and CHM1³¹⁹, as suitable targets for protective allo-restricted human CD8⁺ T-cell responses against non-immunogenic ET and may benefit new therapeutic strategies in ET patients treated with allogeneic stem cell transplantation.

No improvement of survival with reduced- versus high-intensity conditioning for allogeneic stem cell transplants in Ewing tumor patients

BACKGROUND

Outcomes of Ewing tumor (ET) patients treated with allogeneic stem cell transplantation (allo-SCT) were compared regarding the use of reduced-intensity conditioning (RIC) and high-intensity conditioning (HIC) regimens as well as human leukocyte antigen (HLA)-matched and HLA-mismatched grafts.

PATIENTS AND METHODS

We retrospectively analyzed data of 87 ET patients from the European Group for Blood and Marrow Transplantation, Pediatric Registry for Stem Cell Transplantations, Asia Pacific Blood and Marrow Transplantation and MetaEICESS registries treated with allo-SCT. Fifty patients received RIC (group A) and 37 patients received HIC (group B). Twenty-four patients received HLA-mismatched grafts and 63 received HLA-matched grafts.

RESULTS

Median overall survival was 7.9 months [±1.24, 95% confidence interval (CI) 5.44-10.31] for group A and 4.4 months (±1.06, 95% CI 2.29-6.43) for group B patients (P = 1.3). Death of complications (DOC) occurred in 4 of 50 (0.08) and death of disease (DOD) in 33 of 50 (0.66) group A and in 16 of 37 (0.43) and 17 of 37 (0.46) group B patients, respectively. DOC incidence was decreased (P < 0.01) and DOD/relapse increased (P < 0.01) in group A compared with group B. HLA mismatch was not generally associated with graft-versus-Ewing tumor effect (GvETE).

CONCLUSIONS

There was no improvement of survival with RIC compared with HIC due to increased DOD/relapse incidence after RIC despite less DOC incidence. This implicates general absence of a clinically relevant GvETE with current protocols.

Current therapeutic approaches in metastatic and recurrent ewing sarcoma

Ewing sarcoma (ES) is the second most common type of primary bone malignancy in children and young adults. Survival rates for localized ES have improved to upwards of 70% with aggressive chemotherapy and local control. On the other hand, there has been little improvement in survival rates for patients with metastatic or recurrent ES. Herein we review the different current therapeutic approaches available, including the different upfront and salvage chemotherapy regimens, the role for stem cell transplantation, and potential use of immunotherapy.

Ewing's Sarcoma and Second Malignancies

Ewing's sarcoma (ES) is a rare tumor that is most common in children and young adults. Late effects of ES therapy include second cancers, a tragic outcome for survivors of such a young age. This paper will explore the frequencies and types of malignancies that occur after ES. Additionally, it will review how second malignancies have changed with the shift in treatment from high-dose radiation to chemotherapy regimens including alkylators and epipodophyllotoxins. The risk of additional cancers in ES survivors will also be compared to survivors of other childhood cancers. Finally, the possible genetic contribution to ES and second malignancies will be discussed.

Primary disseminated multifocal Ewing sarcoma: results of the Euro-EWING 99 trial

PURPOSE

To improve the poor prognosis of patients with primary disseminated multifocal Ewing sarcomas (PDMES) with a dose-intense treatment concept.

PATIENTS AND METHODS

From 1999 to 2005, 281 patients with PDMES were enrolled onto the Euro-EWING 99 R3 study. Median age was 16.2 years (range, 0.4 to 49 years). Recommended treatment consisted of six cycles of vincristine, ifosfamide, doxorubicin, and etoposide (VIDE), one cycle of vincristine, dactinomycin, and ifosfamide (VAI), local treatment (surgery and/or radiotherapy), and high-dose busulfan-melphalan followed by autologous stem-cell transplantation (HDT/SCT).

RESULTS

After a median follow-up of 3.8 years, event-free survival (EFS) and overall survival (OS) at 3 years for all 281 patients were 27% +/- 3% and 34% +/- 4% respectively. Six VIDE cycles were completed by 250 patients (89%); 169 patients (60%) received HDT/SCT. The estimated 3-year EFS from the start of HDT/SCT was 45% for 46 children younger than 14 years. Cox regression analyses demonstrated increased risk at diagnosis for patients older than 14 years (hazard ratio [HR] = 1.6), a primary tumor volume more than 200 mL (HR = 1.8), more than one bone metastatic site (HR = 2.0), bone marrow metastases (HR = 1.6), and additional lung metastases (HR = 1.5). An up-front risk score based on these HR factors identified three groups with EFS rates of 50% for score <or= 3 (82 patients), 25% for score more than 3 to less than 5 (102 patients), and 10% for score >or= 5 (70 patients; P < .0001).

CONCLUSION

PDMES patients may survive with intensive multimodal therapy. Age, tumor volume, and extent of metastatic spread are relevant risk factors. A score based on these factors may facilitate risk-adapted treatment approaches.

Ewing's sarcoma

Progress in the treatment of Ewing's sarcoma, the second most common bone tumour in children and adolescents, has improved survival from about 10% in the period before chemotherapy was introduced to about 75% today for patients with localised tumours. However, patients with metastases still fare badly, and the therapy carries short-term and long-term toxicities. Multidisciplinary care is indispensable for these patients. Molecular techniques and new imaging modalities are affecting the diagnosis and classification of patients with Ewing's sarcoma. Cooperative group studies have led to chemotherapy regimens using the same drugs (vincristine, doxorubicin, cyclophosphamide, ifosfamide, and etoposide), although the exact regimens differ in Europe and North America. The EWS-ETS family of gene fusions and their downstream effects in Ewing's sarcomas provide opportunities for new approaches to treatment. These include the inhibition of the fusion gene or its protein product, and pathways related to IGF1 and mTOR. Inhibition of tyrosine kinases, exploitation of non-apoptotic cell death, and interference with angiogenesis are promising new approaches. With many new approaches and relatively few patients, it will be challenging to integrate new and established treatments through clinical trials.

The value of local treatment in patients with primary, disseminated, multifocal Ewing sarcoma (PDMES)

BACKGROUND

The value of local treatment in patients with primary, disseminated, multifocal Ewing sarcoma (PDMES) was investigated.

METHODS

We analyzed 120 patients registered into the European Ewing Tumor Working Initiative of National Groups (EURO-E.W.I.N.G. 99) trial at the trial center of Muenster from 1998 to 2006. Median age was 16.2 years. Local treatment of the primary tumor was surgery in 26 of 120 patients, surgery and radiotherapy in 21 patients, and definitive radiotherapy in 40 patients. For treatment of metastases, 6 of 120 patients received surgery; 9 patients, surgery and radiotherapy; and 33 patients, definitive radiotherapy. Forty-seven (39%) patients had local treatment of both the primary tumor and metastases, 41 (34%) patients of either the primary tumor or metastases, and 32 (27%) received no local therapy.

RESULTS

Event-free survival (EFS) at 3 years was 0.24 (95% CI, 0.16-0.33). Univariate analyses demonstrated the impact of local therapy given to the primary tumor: 3-year EFS was 0.25 with surgery, 0.47 with surgery and radiotherapy, 0.23 with radiotherapy, and 0.13 when no local therapy was administered (P < .001). Three-year EFS in PDMES was also influenced by the local treatment: surgery, 0.33; surgery and radiotherapy, 0.56; radiotherapy, 0.35; no local therapy, 0.16 (P = .003). Three-year EFS was 0.39 in patients who received local treatment of both primary tumor and PDMES, compared with 0.17 in patients with any local treatment of either primary tumor or PDMES and 0.14 in patients with no local therapy (P < .001). Multivariate analysis showed absence of local treatment to be the major risk factor (HR = 2.21; P = .027; n = 20).

CONCLUSIONS

Local therapy of involved sites is important for patients with PDMES and should complement systemic treatment whenever possible.

Autologous and allogeneic cellular therapies for high-risk pediatric solid tumors

Since the 1950s, the overall survival of children with cancer has gone from almost zero to approaching 80%. Although there have been notable successes in treating solid tumors such as Wilms tumor, some childhood solid tumors have continued to elude effective therapy. With the use of megatherapy techniques such as tandem transplantation, dose escalation has been pushed to the edge of dose-limiting toxicities, and any further improvements in event-free survival will have to be achieved through novel therapeutic approaches. This article reviews the status of autologous and allogeneic hematopoietic stem cell transplantation (HSCT) for many pediatric solid tumor types. Most of the clinical experience in transplant for pediatric solid tumors is in the autologous setting, so some general principles of autologous HSCT are reviewed. The article then examines HSCT for diseases such as Hodgkin disease, Ewing sarcoma, and neuroblastoma, and the future of cell-based therapies by considering some experimental approaches to cell therapies.

Ewing sarcoma family of tumors

The Ewing sarcoma family of tumors (ESFT) consists of a group of tumors characterized by morphologically similar round-cell neoplasm and by the presence of a common chromosomal translocation. Although rare, such tumors constitute the third most frequent primary sarcoma of bone after osteosarcoma and chondrosarcoma. ESFT most commonly affects young children and adolescents. Because most patients with clinically apparent localized disease at diagnosis may also have occult metastatic (ie, systemic) disease, multidrug chemotherapy as well as local disease control with surgery and/or radiation therapy are indicated for all patients. Despite marked improvements in survival during the past 40 years for patients with localized disease, lesser improvements have been seen in patients with metastatic or recurrent disease. A better understanding of the complex biology of ESFT may lead to the successful development of biologically targeted therapies. As the regulatory pathways responsible for transformation, growth, and metastasis of ESFT become more refined, the number of potential therapeutic targets will expand.

Chemotherapy in Ewing's sarcoma

Ewing's sarcoma constitutes three per cent of all pediatric malignancies. Ewing's sarcoma has generally been more responsive to chemotherapy than adult-type sarcomas, and chemotherapy is now recommended for all patients with this disease. It is essential to integrate local control measures in the form of surgery and/or radiotherapy at the appropriate time, along with chemotherapy to eradicate the disease. This approach has improved the survival substantially to the tune of 70% in localized disease, although outcome for metastatic disease remains dismal. Newer therapeutic approaches are required to improve outcome for metastatic and recurrent or refractory Ewing's sarcoma in organized co-operative group trials.