Which Patients With Rhabdomyosarcoma Need Radiotherapy? Analysis of the Radiotherapy Strategies of the CWS-96 and CWS-2002P Studies and SoTiSaR Registry.

PURPOSE: To analyze and compare the indications, doses, and application methods of radiotherapy (RT) and their influence on prognosis of patients with localized rhabdomyosarcoma (RMS). METHODS: One thousand four hundred seventy patients with localized RMS 21 years and younger entered on CWS-96, CWS-2002P, and SoTiSaR were eligible for the analysis. The median follow-up was 6.5 years (IQR, 3.3-9.5). RESULTS: The 5-year event-free survival (EFS) and local control survival (LCS) for 910 (62%) irradiated versus nonirradiated patients were 71% versus 69% and 78% versus 73% (P = .03), respectively. Ninety-five percent of patients in IRS I (90% embryonal RMS [eRMS]) were nonirradiated (EFS, 87%). Irradiated patients with IRS II had improved LCS (91% v 80%; P = .01) and EFS (not significant). In IRS III, EFS and LCS were significantly better for RT patients: 71% versus 56% (P = 3.1e-06) and 76% versus 61% (P = 4.1e-07). Patients with tumors in the head and neck region (orbita, parameningeal, and nonparameningeal) and in other sites had significantly better EFS and LCS and in parameningeal also overall survival (OS). The efficacy of low RT doses of 32 Gy (hyperfractionated, accelerated RT [HART]) and 36 and 41.4 Gy (conventional fractionated RT [CFRT]) in the favorable groups and higher doses of 44.8 Gy (HART) and 50.4 and 55.4 Gy (CFRT) in the unfavorable groups was comparable. Proton RT was used predominantly in head/neck-parameningeal (HN-PM) tumors, with similar EFS and LCS to photon RT. CONCLUSION: RT can be omitted in patients with IRS I eRMS. RT improves LCS and EFS in IRS II and III. RT improves OS in patients with HN-PM, with proton RT comparable with photon RT. Doses of 32 Gy (HART) or 36 and 41.4 Gy (CFRT) had comparable efficacy in patients with favorable risk profiles and 44.8 Gy (HART) or 50.4 and 55.8 Gy (CFRT) in the unfavorable groups.

Pediatric Patients with Stage IV Rhabdomyosarcoma Significantly Benefit from Long-Term Maintenance Therapy: Results of the CWS-IV 2002 and the CWS DOK IV 2004-Trials.

Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma (STS) in childhood. Whereas more than 90% of patients with localized low-risk RMS can be cured, metastatic RMS have a dismal outcome, with survival rates of less than 30%. The HD CWS-96 trial showed an improved outcome for patients receiving maintenance therapy after completing intensive chemotherapy. Consequently, the international clinical trials CWS-IV 2002 and CWS DOK IV 2004 on metastatic disease of STS of the Cooperative Weichteilsarkom Studiengruppe (CWS) were designed in addition to the CWS-2002P trial for localized RMS disease. All patients received a multimodal intensive treatment regimen. To maintain remission, three options were compared: long-term maintenance therapy (LTMT) versus allogeneic hematopoietic stem cell transplantation (alloHSCT) versus high-dose chemotherapy (HDCT). A total of 176 pediatric patients with a histologically confirmed diagnosis of metastatic RMS or RMS-like tumor were included. A total of 89 patients receiving LTML showed a significantly better outcome, with an event-free survival (EFS) of 41% and an overall survival (OS) of 53%, than alloHSCT (n = 21, EFS 19%, p = 0.02, OS 24%, p = 0.002). The outcome of LTML was slightly improved compared to HDCT (n = 13, EFS 35%, OS 34%). In conclusion, our data suggest that in patients suffering from metastatic RMS, long-term maintenance therapy is a superior strategy in terms of EFS and OS compared to alloHSCT. EFS and OS of HDCT are similar in these strategies; however, the therapeutic burden of LTMT is much lower.

Pre-operative radiotherapy is associated with superior local relapse-free survival in advanced synovial sarcoma.

PURPOSE: Optimization of local therapies in synovial sarcoma (SS) considered unresectable at diagnosis is needed. We evaluated the effects of neoadjuvant versus adjuvant radiation versus surgery only on long-term outcomes. METHODS: Patients with macroscopic SS tumors before chemotherapy (IRS-group-III) in the trials CWS-81, CWS-86, CWS-91, CWS-96, CWS-2002-P and SoTiSaR-registry were analyzed. Local therapies were scheduled after 3 neoadjuvant chemotherapy cycles. RESULTS: Median age of 145 patients was 14.5 years. 106 survivors had median follow-up of 7.0 years. Tumor site was 96 extremities, 19 head-neck, 16 shoulder/hip, 14 trunk. Tumors were < 3 cm in 16, 3-5 cm in 28, 5-10 cm in 55, > 10 cm in 34 patients. In a secondary resection during chemotherapy, R0-status was accomplished in 82, R1 in 30, R2 in 21 (12 missing). Radiotherapy was administered to 115 (R0 61, R1 29, R2 20, missing 5), thereof 57 before and 52 after tumor resection. 23 were treated with surgery only. For all patients, 5 year event-free (EFS) and overall survival (OS) was 68.9% ± 7.6 (95%CI) and 79.1% ± 6.9. To establish independent significance, tumor site, size, surgical results and sequencing of local therapies were analyzed in a Cox regression analysis. Variables associated with EFS and OS are site, size and sequencing of local therapies. Variables associated with local recurrence are site, surgical results and sequencing of local therapies. The only variable associated with suffering metastatic recurrence is tumor size. CONCLUSION: Differences in sequencing of local therapy procedures are independently associated with outcomes. Best local control is achieved when tumors are irradiated pre-operatively and undergo R0 or R1 resection thereafter.

No Improvement of Survival for Alveolar Rhabdomyosarcoma Patients After HLA-Matched Versus -Mismatched Allogeneic Hematopoietic Stem Cell Transplantation Compared to Standard-of-Care Therapy.

Background: Patients with stage IV alveolar rhabdomyosarcoma (RMA) have a 5-year-survival rate not exceeding 30%. Here, we assess the role of allogeneic hematopoietic stem cell transplantation (allo-HSCT) for these patients in comparison to standard-of-care regimens. We also compare the use of HLA-mismatched vs. HLA-matched grafts after reduced vs. myeloablative conditioning regimens, respectively. Patients and Methods: In this retrospective analysis, we compare event-free survival (EFS), overall survival (OS), and toxicity of HLA-mismatched vs. -matched transplanted patients in uni- and multivariate analyses (total: n = 50, HLA-matched: n = 15, HLA-mismatched: n = 35). Here, the factors age at diagnosis, age at allo-HSCT, sex, Oberlin score, disease status at allo-HSCT, and HLA graft type are assessed. For 29 primarily transplanted patients, three matched non-transplanted patients per one transplanted patient were identified from the CWS registry. Outcomes were respectively compared for OS and EFS. Matching criteria included sex, age at diagnosis, favorable/unfavorable primary tumor site, and metastatic sites. Results: Median EFS and OS did not differ significantly between HLA-mismatched and -matched patients. In the mismatched group, incidence of acute GvHD was 0.87 (grade III-IV: 0.14) vs. 0.80 in HLA-matched patients (grade III-IV: 0.20). Transplant-related mortality (TRM) of all patients was 0.20 and did not differ significantly between HLA-mismatched and -matched groups. A proportion of 0.58 relapsed or progressed and died of disease (HLA-mismatched: 0.66, HLA-matched: 0.53) whereas 0.18 were alive in complete remission (CR) at data collection. Multivariate and competing risk analyses confirmed CR and very good partial response (VGPR) status prior to allo-HSCT as the only decisive predictor for OS (p < 0.001). Matched-pair survival analyses of primarily transplanted patients vs. matched non-transplanted patients also identified disease status prior to allo-HSCT (CR, VGPR) as the only significant predictor for EFS. Here, OS was not affected, however. Conclusion: In this retrospective analysis, only a subgroup of patients with good response at allo-HSCT survived. There was no survival benefit of allo-transplanted patients compared to matched controls, suggesting the absence of a clinically relevant graft-versus-RMA effect in the current setting. The results of this analysis do not support further implementation of allo-HSCT in RMA stage IV patients.

Fusion transcripts as liquid biopsy markers in alveolar rhabdomyosarcoma and synovial sarcoma: A report of the Cooperative Weichteilsarkom Studiengruppe (CWS).

BACKGROUND: The possible application of gene fusion transcripts as tumor-specific noninvasive liquid biopsy biomarkers was investigated in blood plasma from patients with alveolar rhabdomyosarcoma (ARMS) and synovial sarcoma (SS). METHODS: Patients entered in the CWS Soft-Tissue Sarcoma Registry (SoTiSaR) with tumors positive for fusion genes and available blood/plasma samples were included in our analysis. Cell-free exosomal RNA was extracted and used to detect PAX-FOXO1 or SYT-SSX fusion transcripts by reverse transcription quantitative PCR (RT-qPCR). RESULTS: The analysis included 112 ethylene diamine tetraacetic acid blood samples from 80 patients (65 with ARMS, 15 with SS; 34 with localized, 46 with metastatic disease). For patients with metastatic ARMS, 62% (n = 18) of initial liquid biopsies were positive, and 16 (89%) of them showed initial bone marrow (BM) metastases. For all patients with primary localized ARMS, liquid biopsy was negative at diagnosis. Of the 48 plasma samples collected during therapy and follow-up, five were positive. None of the liquid biopsies from patients with SS were positive. CONCLUSIONS: This liquid biopsy assay based on the detection of fusion transcripts in cell-free RNA from blood exosomes is suitable for analysis of patients with ARMS. Results showed good correlation with the initial tumor status; liquid biopsy was positive in 94% of patients with metastatic ARMS and initial BM involvement, whereas biopsies from all patients with localized tumors were negative. Prospective validation and optimization of the assay, as well as its application for other markers in diagnostics and monitoring of soft-tissue sarcoma, are ongoing.

Secondary malignant neoplasms after bone and soft tissue sarcomas in children, adolescents, and young adults.

BACKGROUND: Increased survival in young sarcoma patients comes along with a higher incidence of second malignant neoplasms (SMNs). The incidence, latency, histiotype, and outcome of these patients were analyzed because this information is essential to design evidence-based long-term follow-up care programs for young sarcoma survivors. METHODS: Patients entered on clinical trials or registered in registries with a primary sarcoma in 1 of the cooperative sarcoma study groups in the framework of the Society for Pediatric Oncology and Hematology (GPOH) were screened for SMNs. Descriptive analysis, the Kaplan-Meier method, the Gray model, the Fine-Gray model, and the Cox regression model were used for the statistical analyses. RESULTS: A total of 159 out of 7079 (2.2%) patients were registered with a SMN. Among them, 104 solid SMNs (65%) and 56 hematologic SMNs (35%) occurred. Median latency from first diagnosis of sarcoma to the diagnosis of SMN was 6.8 years (range, 0-26.7 years). Cumulative incidence of SMN was 8.8% after 30 years. Five-year-survival was 67.1% (95% confidence interval [CI], 66.0-68.2) for the 7079 patients and it was 45.1% (95% CI, 36.2-53.6) after the diagnosis of a SMN (subcohort of n = 159 patients). CONCLUSIONS: There is a remarkable high cumulative incidence of SMNs after bone and soft tissue sarcomas in children, adolescents, and young adults. Therefore, effective transition as well as risk adapted long-term follow-up care programs should be developed and offered to young sarcoma survivors. LAY SUMMARY: Bone sarcomas and soft tissue tumors are rare tumors in children, adolescents, and young adults. The treatment varies, but may comprise chemotherapy, surgery, and/or radiotherapy. Developing a subsequent malignant tumor is a long-term risk for the patients. To better characterize this risk, we analyzed the data of 7079 patients (up to 21 years old) with bone sarcomas or soft tissue tumors. Our findings provide a basis to counsel young sarcoma survivors on their individual risk of subsequent malignant tumors. Moreover, these data can help to establish recommendations for aftercare in young sarcoma survivors.

Extraskeletal Ewing sarcoma in children, adolescents, and young adults. An analysis of three prospective studies of the Cooperative Weichteilsarkomstudiengruppe (CWS).

BACKGROUND: We have analyzed the outcome of patients with localized extraskeletal Ewing sarcoma (EES) treated in three consecutive Cooperative Weichteilsarkomstudiengruppe (CWS) soft tissue sarcoma (STS) studies: CWS-91, CWS-96, and CWS-2002P. METHODS: Patients were treated in CWS-91 with four- (vincristine, dactinomycin, doxorubicin, and ifosfamide [VAIA] or cyclophosphamide [VACA II]) or five-drug (+etoposide [EVAIA]) cycles, in CWS-96 they were randomly assigned to receive VAIA or CEVAIE (+carboplatin and etoposide), and in CWS-2002P with VAIA III plus optional maintenance therapy (MT) with cyclophosphamide and vinblastine. Local therapy consisted of resection and/or radiotherapy (RT). RESULTS: Two hundred forty-three patients fulfilled the eligibility criteria. The 5-year event-free survival (EFS) and overall survival (OS) were 63% (95% confidence interval [CI] 57-69) and 73% (95% CI 67-79), respectively. The 5-year EFS by study was 64% (95% CI 54-74) in CWS-91, 57% (95% CI 48-66) in CWS-96, and 79% (95% CI 67-91) in CWS-2002P (n.s.). The 5-year OS was 72% (95% CI 62-82) in CWS-91, 70% (95% CI 61-79) in CWS-96, and 86% (95% CI 76-96) in CWS-2002P (n.s.). In CWS-96, 5-year EFS and OS in the VAIA arm versus the CEVAIE were 65% (95% CI 52-81) versus 55% (95% CI 39-76) log-rank p = .13, and 85% (95% CI 75-96) versus 61% (95% CI 45-82), log-rank p = .09. CONCLUSION: Our analysis provides interesting information on the treatment and specificities of EES, which can be useful for a better understanding of this rare entity and should be considered in the development of future clinical trials for Ewing sarcoma defined as FET-ETS fusion positive tumors.

Rhabdomyosarcoma of the female genitourinary tract: Primary and relapsed disease in infants and older children. Treatment results of five Cooperative Weichteilsarkom Studiengruppe (CWS) trials and one registry.

BACKGROUND: Rhabdomyosarcoma (RMS) of the female genitourinary tract (FGU-RMS) located at the vagina or uterus is one of the most favorable RMS sites. Little is known about treatment and outcome in infants and relapsed disease (RD). METHODS: Characteristics, treatment, and outcome of 71 children with FGU-RMS registered within five Cooperative Weichteilsarkom Studiengruppe (CWS) trials and one registry (1981-2019) were evaluated. RESULTS: FGU-RMS was diagnosed in 67 patients with localized disease (LD) at a median age of 2.89 years (0.09-18.08). Multimodal treatment consisted of chemotherapy (CHT) (n = 66), secondary surgery (n = 32), and radiotherapy (n = 11). Age at diagnosis ≤12 months was the only significant negative prognostic factor influencing the event-free survival (EFS). Ten-year EFS and overall survival (OS) for infants ≤12 months were 50% and 81%, respectively. In contrast, children with LD >1 year and ≤10 years had a 10-year EFS and OS of 78% and 94% (P = .038), and >10 years of 82% and 88%, respectively (P = .53). Metastatic disease was observed in four patients of which three are alive. RD occurred in five of 12 infants ≤1 year and 10/55 children at a median of 1.38 years (0.53-2.97) after initial diagnosis. Treatment of patients with RD consisted of multimodal treatment (n = 13) or resection only (n = 2). Nine patients (60%) were alive in clinical remission at a median of 7.02 years (1.23-16.72) after diagnosis of RD. CONCLUSION: Infants with FGU-RMS have a higher relapse rate than older children with FGU-RMS, but prognosis is fair.

Malignant peripheral nerve sheath tumors in children, adolescents, and young adults: Treatment results of five Cooperative Weichteilsarkom Studiengruppe (CWS) trials and one registry.

BACKGROUND AND OBJECTIVES: Malignant peripheral nerve sheath tumors (MPNST) are aggressive soft tissue sarcomas that present as large, invasive tumors. Our aim was to assess outcomes, identify prognostic factors, and analyze treatment strategies in a prospectively collected pediatric cohort. METHODS: Patients less than 21 years with MPNST treated in the consecutive prospective European Cooperative Weichteilsarkom Studiengruppe (CWS)-trials (1981-2009) and the CWS-SoTiSaR registry (2009-2015) were analyzed. RESULTS: A total of 159 patients were analyzed. Neurofibromatosis type I (NF1) was reported in thirty-eight patients (24%). Most were adolescents (67%) with large (>10 cm, 65%) tumors located at extremities (42%). Nodal involvement was documented in 15 (9%) and distant metastases in 15 (9%) upon diagnosis. Overall, event-free survival (EFS) was 40.5% at 5 and 36.3% at 10 years, and overall survival (OS) was 54.6% at 5 and 47.1% at 10 years. Age, NF1 status, tumor site, tumor size, Intergroup Rhabdomyosarcoma Study (IRS) group, metastatic disease, and achieving first complete remission (CR1) were identified as prognostic factors for EFS and/or OS in the univariate analysis. CONCLUSIONS: Prognostic factors were identified and research questions for future clinical trials were addressed.

Patterns of Prior and Subsequent Neoplasms in Children and Adolescents With Soft Tissue Sarcomas.

BACKGROUND: The occurrence of prior, concurrent and subsequent neoplasms (SN) represents a serious problem in children and adolescents with soft tissue sarcomas. Pathogenic germline variants contribute to the diagnosis of multiple neoplasms in sarcoma survivors. MATERIALS AND METHODS: The records of 748 children and adolescents, diagnosed with soft tissue sarcomas and registered in trials/registries by the cooperative soft tissue sarcoma (Cooperative Weichteilsarkom Studie) group, were reviewed for the occurrence of SNs. Reference histology review was available for all cases; the presence of oncogenic fusions known at the time of diagnosis was confirmed for fusion-positive (F+) entities. RESULTS: Concurrent or subsequent SNs developed in 13 of 473 survivors of fusion-negative (F-) sarcomas, for an 8-year cumulative SN incidence of 5% in survivors of F- sarcomas. In contrast, only 1 of 278 survivors of F+ sarcoma developed an SN. Twenty of 748 patients with soft tissue sarcomas had a history of prior neoplasms. Six of 14 patients who developed SNs after their index sarcomas met Chompret criteria for Li-Fraumeni syndrome. Nine of 20 patients who had tumors before their index sarcoma diagnosis had neurofibromatosis type 1 or neurofibromatosis type 1 spectrum tumors. CONCLUSION: Sarcoma phenotype/genotype and the sequence and nature of prior and subsequent neoplasms provide a window into underlying germline genetic susceptibilities in children and adolescents with soft tissue sarcomas.

Endothelial cell malignancies in infants, children and adolescents: Treatment results of three Cooperative Weichteilsarkom Studiengruppe (CWS) trials and one registry.

BACKGROUND: Endothelial cell malignancies are extremely rare in childhood. New identification of genetic abnormalities (WWTR1:CAMTA1 translocation) helps to recognize potential therapeutic targets. Little is known about treatment and outcome of these patients. METHODS: Clinical course, treatment, and outcome in patients with endothelial cell malignancies treated within the Cooperative Weichteilsarkom Studiengruppe (CWS) trials CWS-91, -96, -2002P, and the Soft-Tissue Sarcoma Registry (SoTiSaR) were analyzed (1991-2019). RESULTS: Patients had angiosarcoma (AS) (n = 12), malignant epithelioid hemangioendothelioma (EHE) (n = 16), and kaposiform hemangioendothelioma (KHE) (n = 13). The median age was 5.39 years (range, 0.8-17.34); 33 patients had localized disease (LD), and 8 patients had metastatic disease. Therapy consisted of chemotherapy (CHT) (AS n = 8, EHE n = 9, KHE n = 5), interferon or new agent therapy (EHE n = 5, 2 KHE n = 2), microscopically or macroscopically complete resection (AS n = 3, EHE n = 6, KHE n = 3), and radiotherapy (AS n = 6, EHE n = 2, KHE n = 1). Two patients (KHE) had watch-and-wait strategy resulting in stable disease. Complete remission (CR) was achieved in AS (10/12; 83%), EHE (10/16; 63%), and KHE (5/13; 38%). The five-year EFS and OS for patients with AS was 64% (± 29 CI 95%) and 80% (± 25, CI 95%), with EHE 62% (± 24, CI 95%) and 78% (± 23, CI 95%), with KHE 33% (± 34, CI 95%) and 92% (± 15, CI 95%), respectively. Complete resection was a significant prognostic factor for AS, LD for EHE. CONCLUSIONS: Endothelial cell malignancies in childhood have a fair outcome with multimodal treatment. New treatment options are needed for metastic disease.

The impact of local control in the treatment of children with advanced infantile and adult-type fibrosarcoma: Experience of the cooperative weichteilsarkom studiengruppe (CWS).

BACKGROUND AND OBJECTIVES: This study aims at examining the potential survival benefits of primary versus secondary surgery of children diagnosed with advanced infantile (iFS) and adult-type fibrosarcoma (aFS). METHODS: Treatment and outcome of 89 children with FS treated within prospective Cooperative Studiengruppe (CWS) trials (1981-2016) were analyzed retrospectively. RESULTS: Localized disease (LD) was diagnosed in 87 patients: 64/66 patients with iFS (≤2 years) and 23 with aFS (>2 ≤ 18 years). Two patients (iFS) had metastatic disease. Resection was the mainstay of therapy of patients with LD resulting in microscopically complete (R0, IRS group I) (n = 29/87, 33%), microscopically incomplete (R1, IRS group II) (n = 17/87, 20%) and macroscopically incomplete (R2, IRS group III) (n = 41/87, 47%). Advanced LD (IRS group III) was present in 32/64 (50%) patients with iFS and in 9/23 (39%) with aFS. Chemotherapy was added predominantly in patients with advanced disease and an assessable objective response to CHT was seen in 71% iFS and 75% aFS. The 5-year event-free survival (EFS) of patients with iFS and aFS was 81% (±10, 95% CI) and 70% (±19, 95% CI) (p = 0.24); the 5-year overall survival (OS) was 98% (±3, 95% CI) and 82% (±16, 95% CI) (p = 0.02). Primary resection was no prognostic factor. Secondary R0/ R1 resection in patients with advanced disease improved 5-year EFS and OS in aFS (p = 0.002 and p = 0.000) but not in infants. CONCLUSIONS: Secondary resection improves outcome in advanced aFS but not in infants. Mutilating surgery in infants should be avoided. TYPE OF STUDY AND LEVEL OF EVIDENCE: Treatment study: patients were enrolled in five prospective studies and one registry, prognosis study: retrospective study. LEVEL OF EVIDENCE: II/ III. MINI-ABSTRACT: Fibrosarcoma is a very rare malignant tumor. Little is known about differences of local treatment of advanced infantile and adult-type. Data of 89 patients registered in five prospective trials and one registry of the Cooperative Weichteilsarkom Studiengruppe (CWS) (1981-2016) were analyzed.

Epithelioid sarcoma in children, adolescents, and young adults: Localized, primary metastatic and relapsed disease. Treatment results of five Cooperative Weichteilsarkom Studiengruppe (CWS) trials and one registry.

BACKGROUND: Epithelioid sarcoma (ES) is a rare malignant soft-tissue tumor. Little is known about the optimal treatment of primary localized (LD), metastatic (MD), and relapsed disease (RD). METHODS: Characteristics, treatment, and outcome of 67 patients registered within the Cooperative Weichteilsarkom Studiengruppe CWS-81, -86, -91, -96, -2002P trials and the registry SoTiSaR were analyzed (1981-2016). RESULTS: The median age was 14 years (range, 0.7-26.9); 53 patients had localized disease (LD) and 14 metastatic disease (MD). A total of 58 of 67 patients were treated with primary resection. Resection was microscopically complete (R0) in 35, microscopically incomplete (R1) in 12, macroscopically incomplete (R2) in 20 patients. Radiotherapy (RT) was administered to 33 of 67 patients and 49 of 67 patients received chemotherapy (CHT). Complete remission (CR) was achieved in 45 of 53 (85%) patients with LD. Twenty-seven of 53 patients relapsed after a median time of 0.9 years (range, 0.1-2.3). Relapse therapy consisted of resection (n = 19/27), RT (n = 10/27), CHT (n = 12/27), and limb perfusion (n = 3/27). The five-year event-free survival and overall survival of patients with LD, MD, and RD was 35% (± 12, CI 95%) and 58% (± 14, CI 95%), 7% (± 14, CI 95%), and 9% (± 16, CI 95%), 24% (± 17, CI 95%), and 40% (± 20, CI 95%), respectively. Tumor size, IRS group, tumor invasiveness, nodal status, and best resection correlated with a favorable prognosis in patients with LD while best resection was the only significant factor in patients with RD. CONCLUSIONS: Complete tumor resection correlates with long-term survival in patients with ES.

Desmoplastic small round cell tumors: Multimodality treatment and new risk factors.

BACKGROUND: To evaluate optimal therapy and potential risk factors. METHODS: Data of DSRCT patients <40 years treated in prospective CWS trials 1997-2015 were analyzed. RESULTS: Median age of 60 patients was 14.5 years. Male:female ratio was 4:1. Tumors were abdominal/retroperitoneal in 56/60 (93%). 6/60 (10%) presented with a localized mass, 16/60 (27%) regionally disseminated nodes, and 38/60 (63%) with extraperitoneal metastases. At diagnosis, 23/60 (38%) patients had effusions, 4/60 (7%) a thrombosis, and 37/54 (69%) elevated CRP. 40/60 (67%) patients underwent tumor resection, 21/60 (35%) macroscopically complete. 37/60 (62%) received chemotherapy according to CEVAIE (ifosfamide, vincristine, actinomycin D, carboplatin, epirubicin, etoposide), 15/60 (25%) VAIA (ifosfamide, vincristine, adriamycin, actinomycin D) and, 5/60 (8%) P6 (cyclophosphamide, doxorubicin, vincristine, ifosfamide, etoposide). Nine received high-dose chemotherapy, 6 received regional hyperthermia, and 20 received radiotherapy. Among 25 patients achieving complete remission, 18 (72%) received metronomic therapies. Three-year event-free (EFS) and overall survival (OS) were 11% (±8 confidence interval [CI] 95%) and 30% (±12 CI 95%), respectively, for all patients and 26.7% (±18.0 CI 95%) and 56.9% (±20.4 CI 95%) for 25 patients achieving remission. Extra-abdominal site, localized disease, no effusion or ascites only, absence of thrombosis, normal CRP, complete tumor resection, and chemotherapy with VAIA correlated with EFS in univariate analysis. In multivariate analysis, significant factors were no thrombosis and chemotherapy with VAIA. In patients achieving complete remission, metronomic therapy with cyclophosphamide/vinblastine correlated with prolonged time to relapse. CONCLUSION: Pleural effusions, venous thrombosis, and CRP elevation were identified as potential risk factors. The VAIA scheme showed best outcome. Maintenance therapy should be investigated further.

Inflammatory myofibroblastic tumors-A retrospective analysis of the Cooperative Weichteilsarkom Studiengruppe.

BACKGROUND: Inflammatory myofibroblastic tumors (IMTs) are a rare subgroup of soft tissue tumors. The outcome of patients with IMT has been reported as favorable when the tumor is completely resected. If surgical resection is not possible, systemic therapy has to be considered. However, the best systemic treatment and response rates are currently unclear. METHODS: Thirty-eight patients under the age of 21, who were registered between 2000 and 2014 with a primary diagnosis of IMT, were analyzed. RESULTS: IMT was typically localized intra-abdominally or in the pelvis. In 20 patients, the tumor was resected without further therapy; 17 patients were in complete remission at last evaluation and two patients were in partial remission. Eighteen patients received systemic therapy, 15 of whom had macroscopically incomplete resection. Systemic therapy most commonly consisted of regimens with dactinomycin, ifosfamide or cyclophosphamide, and vincristine, with or without doxorubicin, and it seemed to reduce tumor extension in individual cases. Five-year event-free survival was 74 ± 14% and 5-year overall survival was 91 ± 10% for all patients. The patients who died due to the disease were those with incomplete resection (n = 3). CONCLUSIONS: Surgery without further systemic therapy was a feasible and acceptable therapeutic option for every second patient with IMT. Standard chemotherapy for pediatric soft tissue sarcoma produced favorable results in individual cases and was able to shrink the tumor enough to enable resection. Superior efficacy of new targeted therapies such as anaplastic lymphoma kinase-inhibitors compared to standard chemotherapy has to be proven in the future.

Synovial Sarcoma Recurrence in Children and Young Adults.

BACKGROUND: Recurrence of synovial sarcoma (SS) has been associated with poor prognosis. Optimal treatment is unknown due to heterogeneous primary therapies with or without chemotherapy. METHODS: Data of patients treated in consecutive prospective European Cooperative Weichteilsarkom Studiengruppe trials 1981-2010 with primary localized SS less than 21 years were analyzed. Chemotherapy had been recommended for all SS patients during primary therapy. RESULTS: Of 220 patients, 52 experienced recurrence a median of 2.5 years (range, 0.3-11.6 years) after their initial diagnosis. Recurrence was local in 22 (42 %), metastatic in 24 (46 %), and combined in 6 (12 %) of the 52 patients. If present, metastases involved the lungs in more than 90 % of the patients. Second remission was achieved by 39 (75 %) of the 52 patients, whereas only 12 (23 %) of the 39 patients maintained it. The median follow-up period for 17 survivors was 6.7 years (range, 3.2-19.6 years). The 5-year post-relapse event-free survival probability was 26 %, and the overall survival probability was 40 %. In the univariable analyses, initial tumor smaller than 3 cm, 2.5 years or longer to recurrence, local relapse only, and R0/R1 resection at relapse correlated with improved survival expectancies. In the multivariable analysis, the only factor retaining significance was R0/R1 resection of the recurrence. No difference between R0 and R1 resections was evident. For the patients with metastatic relapse, maintenance therapy seemed to prolong the time to subsequent recurrences. CONCLUSION: Although 75 % of the patients with first SS recurrence achieved a second remission, only a minority became long-term, disease-free survivors. They had small tumors at initial diagnosis, local relapse as the only site of involvement, and complete resection of their recurrence. Because the majority of patients relapse subsequently, quality-of-life-based treatment approaches prolonging disease-free intervals are needed.

Primary Metastatic Synovial Sarcoma: Experience of the CWS Study Group.

BACKGROUND: Prognostic factors for localized synovial sarcoma are well defined. However, few data exist regarding patients with metastases at diagnosis. Poor outcome is described but the optimal therapeutic regimen remains unclear. Our aim was to assess the outcome, identify prognostic factors, and analyze treatment strategies. METHODS: Patients <21 years with synovial sarcoma and primary distant metastases treated in the consecutive prospective European Cooperative Weichteilsarkom Studiengruppe trials 1980-2010 were analyzed. RESULTS: Twenty-nine of 296 patients had primary metastases. Twenty-seven could be included. Median age was 16.7 years. Primaries were mainly located in the limbs (78%) and 74% were ≥10 cm. Metastases involved the lungs in all patients. Two patients presented with synchronous bone metastases. Sixty-three percent of patients achieved a first remission, whereas only 26% maintained it. Relapses were metastatic with pulmonary metastases in nearly all patients. Five-year event-free survival and overall survival (OS) rates were 26% and 30%, respectively. Prognosis was best for patients with oligometastatic lung metastases (5-year OS probability 85%). Prognosis was worse for patients with multiple bilateral lung metastases (5-year OS 13%) and even poorer for those with concurrent bone metastases. Treatment elements associated with superior survival were adequate local therapy of the primary tumor and, if feasible, for metastases, chemotherapy with an ifosfamide/doxorubicin-based regimen. The use of whole lung irradiation was not correlated with better outcomes. CONCLUSIONS: The overall prognosis of primary metastatic synovial sarcoma is poor. However, individuals with oligometastatic lung metastases had very good chance for long-term survival when treated with adequate multimodal therapy.

Challenges in the local treatment of large abdominal embryonal rhabdomyosarcoma.

BACKGROUND: Embryonal rhabdomyosarcoma is the most common pediatric soft tissue sarcoma. The best local treatment in large, nonmetastatic primary unresected nongenitourinary embryonal rhabdomyosarcoma of the abdomen (LARME) is however unclear. METHODS: We analyzed patients with LARME treated in four consecutive CWS trials. All diagnoses were confirmed by reference reviews. Treatment included multiagent chemotherapy and local treatment of the primary tumor with surgery and/or radiotherapy. The impact of primary debulking surgery (PDS) also was studied. RESULTS: One hundred patients <21 years with a median age of 4 years had LARME. Sixty-one of them had a tumor >10 cm in diameter at diagnosis. PDS was performed in 19 of 100 children. The outcomes of patients with PDS were similar to those of the other patients. In 36 children, the tumor was resected after induction chemotherapy; 60 RME were irradiated. The toxic effects of radiochemotherapy were not significantly increased compared with the nonirradiated patients. With a median follow-up of 10 years, the 5-year EFS and OS were 52 ± 10 and 65 ± 9 %, respectively. Significant risk factors in multivariate analysis were age >10 years; no achievement of complete remission; and inadequate secondary local treatment, defined as incomplete secondary resection or no radiation. CONCLUSIONS: Children with LARME have a fair prognosis, despite an often huge tumor size and unfavorable primary site, if the tumors can either be resected or irradiated following induction chemotherapy. PDS was only performed in a small subgroup. Radiation performed concomitantly with chemotherapy did not increase the acute toxicity significantly.

Survival following disease recurrence of primary localized alveolar rhabdomyosarcoma.

BACKGROUND: Recurrences in primary localized alveolar rhabdomyosarcoma (RMA) are common. Post-relapse survival is poor. We evaluated prognostic factors including relapse treatment in patients with recurrent RMA. METHODS: Relapses occurred in 115/235 patients with nonmetastatic RMA treated in four consecutive CWS-trials after achievement of a complete remission. Sufficient information about post-relapse treatment and outcome could be obtained in 99 patients and was retrospectively analyzed. RESULTS: Nine of 99 patients received no salvage therapy and died after a median of 2 months. The remaining 90 patients received multimodal relapse treatment including mandatory chemotherapy. Recurrences were grossly resected in 39 patients; 57 patients received radiation. At a median follow-up from relapse of 8 years, 20 patients were alive and disease-free (5-year post-relapse survival [PROS] 21.3 ± 8). All surviving patients apart from a single individual had an isolated, circumscribed recurrence. Sixteen of 20 survivors were treated with adequate local relapse therapy (ALRT, i.e., either complete resection or gross resection + radiation). Survival in the subgroup of 27 individuals with circumscribed recurrences and ALRT was significantly better (PROS 53.7 ± 19) compared with disseminated recurrences and/or tumors treated without ALRT. Absence of primary lymph node involvement, circumscribed relapses, ALRT, and achievement of a second CR were identified as independent favorable risk factors. CONCLUSION: Post-relapse survival for primary localized RMA is generally poor. However, certain patient groups differed significantly in their likelihood of survival and 50% of patients with circumscribed relapses treated with ALRT survived. These findings may form the basis for an evidence-based risk-stratification for recurrent disease including relapse treatment.

Treatment of children with metastatic soft tissue sarcoma with oral maintenance compared to high dose chemotherapy: report of the HD CWS-96 trial.

PURPOSE: We prospectively studied the efficacy of high dose therapy (HDT) versus an oral maintenance treatment (OMT) in patients with stage IV soft tissue sarcoma (STS). PATIENTS AND METHODS: Both groups were pretreated with the CEVAIE combination consisting of carboplatin, etoposide, vincristine, actinomycin D, ifosfamide, and epirubicin. HDT consisted of a tandem cycle of thiotepa (600 mg/m(2)) plus cyclophosphamide (4,500 mg/m(2)) and melphalan (120 mg/m(2)) plus etoposide (1,800 mg/m(2)). This treatment was compared with OMT, consisting of four cycles trofosfamide (10 days 2 x 75 mg/m(2)/day) plus etoposide (10 days 2 x 25 mg/m(2)/day), and 4 cycles trofosfamide (10 days 2 x 75 mg/m(2)/day) plus idarubicin (10 days 4 x 5 mg/m(2)). Eligibility criteria were: diagnosis confirmed by reference pathology, primary stage IV, below 22 years of age, and having completed the study therapy. RESULTS: From 96 patients 45 were treated with HDT and 51 with OMT. The main risk parameters were equally distributed in both arms. After a median follow-up of 57.4 months, 11/45 (24.4%) patients in the HDT-arm and 26/51 (57.8%) patients in OMT-arm were alive. Kaplan-Meier analysis demonstrated an overall survival for the whole group of 0.27 (OMT group: 0.52, HDT group 0.27, log rank P = 0.03). The proportional hazard analysis for patients with rhabdomyosarcoma (RMS) or "RMS-like" tumors (77.1% of all patients) demonstrated an independent benefit of OMT on outcome. CONCLUSION: Oral maintenance therapy seems to be a promising option for patients with RMS-like stage IV tumors.