Treatment of unresectable or metastatic pediatric soft tissue sarcomas with surgery, irradiation, and chemotherapy: a Pediatric Oncology Group study

Targeted immunotherapy and nanomedicine for rhabdomyosarcoma: The way of the future

Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma of childhood. Histology separates two main subtypes: embryonal RMS (eRMS; 60%-70%) and alveolar RMS (aRMS; 20%-30%). The aggressive aRMS carry one of two characteristic chromosomal translocations that result in the expression of a PAX3::FOXO1 or PAX7::FOXO1 fusion transcription factor; therefore, aRMS are now classified as fusion-positive (FP) RMS. Embryonal RMS have a better prognosis and are clinically indistinguishable from fusion-negative (FN) RMS. Next to histology and molecular characteristics, RMS risk groupings are now available defining low risk tumors with excellent outcomes and advanced stage disease with poor prognosis, with an overall survival of about only 20% despite intensified multimodal treatment. Therefore, development of novel effective targeted strategies to increase survival and to decrease long-term side effects is urgently needed. Recently, immunotherapies and nanomedicine have been emerging for potent and effective tumor treatments with minimal side effects, raising hopes for effective and safe cures for RMS patients. This review aims to describe the most relevant preclinical and clinical studies in immunotherapy and targeted nanomedicine performed so far in RMS and to provide an insight in future developments.

Proton Therapy in Non-Rhabdomyosarcoma Soft Tissue Sarcomas of Children and Adolescents

This paper provides insights into the use of Proton Beam Therapy (PBT) in pediatric patients with non-rhabdomyosarcoma soft tissue sarcomas (NRSTS). NRSTS are a heterogeneous group of rare and aggressive mesenchymal extraskeletal tumors, presenting complex and challenging clinical management scenarios. The overall survival rate for patients with NRSTS is around 70%, but the outcome is strictly related to the presence of various variables, such as the histological subtype, grade of malignancy and tumor stage at diagnosis. Multimodal therapy is typically considered the preferred treatment for high-grade NRSTS. Radiotherapy plays a key role in the treatment of children and adolescents with NRSTS. However, the potential for radiation-induced side effects partially limits its use. Therefore, PBT represents a very suitable therapeutic option for these patients. The unique depth-dose characteristics of protons can be leveraged to minimize doses to healthy tissue significantly, potentially allowing for increased tumor doses and enhanced preservation of surrounding tissues. These benefits suggest that PBT may improve local control while reducing toxicity and improving quality of life. While clear evidence of therapeutic superiority of PBT over other modern photon techniques in NRSTS is still lacking-partly due to the limited data available-PBT can be an excellent treatment option for young patients with these tumors. A dedicated international comprehensive collaborative approach is essential to better define its role within the multidisciplinary management of NRSTS. Shared guidelines for PBT indications-based on the patient's age, estimated outcome, and tumor location-and centralization in high-level referral centers are needed to optimize the use of resources, since access to PBT remains a challenge due to the limited number of available proton therapy facilities.

Local treatment in initially unresected non-rhabdomyosarcoma soft-tissue sarcomas of children and adolescents: A retrospective single-center experience

BACKGROUND

Pediatric non-rhabdomyosarcoma soft-tissue sarcomas (NRSTS) are a heterogeneous group of aggressive tumors. Patients with locally advanced/initially unresected disease represent a subset of patients with unsatisfactory outcome: limited data are available on the best treatment approach, in particular regarding local therapy.

METHODS

This retrospective analysis concerned 71 patients < 21 years old with nonmetastatic, initially unresected adult-type NRSTS, treated at a referral center for pediatric sarcomas from 1990 to 2021. Patients were treated using a multimodal approach, based on the protocols adopted at the time of their diagnosis.

RESULTS

The series included a selected group of patients with unfavorable clinical characteristics, i.e., most cases had high-grade and large tumors, arising from axial sites in 61% of cases. All patients received neoadjuvant chemotherapy, 58 (82%) had delayed surgery (R0 in 45 cases), and 50 (70%) had radiotherapy. Partial response to chemotherapy was observed in 46% of cases. With a median follow-up of 152 months (range, 18-233), 5-year event-free survival (EFS) and overall survival (OS) were 39.9% and 56.5%, respectively. Survival was significantly better for patients who responded to chemotherapy, and those who had a delayed R0 resection. Local relapse at 5 years was 7.7% for patients who did not undergo delayed surgery.

CONCLUSIONS

Our series underscores the unsatisfactory outcome of initially unresected NRSTS patients. Improving the outcome of this patient category requires therapeutic strategies able to combine novel effective systemic therapies with a better-defined local treatment approach to offer patients the best chances to have R0 surgery.

Pediatric Non-Rhabdomyosarcoma Soft Tissue Sarcomas: Standard of Care and Treatment Recommendations from the European Paediatric Soft Tissue Sarcoma Study Group (EpSSG)

This paper describes the standard of care for patients with non-rhabdomyosarcoma soft tissue sarcomas (NRSTS) and the therapeutic recommendations developed by the European paediatric Soft tissue sarcoma Study Group (EpSSG). NRSTS form a very mixed group of mesenchymal extraskeletal malignancies. Their rarity, heterogeneity, and aggressiveness make the management of children and adolescents with these tumors complex and challenging. The overall cure rate for patients with NRSTS is around 70%, but survival depends on several prognostic variables, such as histotype and tumor grade, extent of disease and stage, tumor size, and tumor site. While surgery remains the mainstay of treatment for most of these tumors, a multimodal therapeutic approach including radiotherapy and chemotherapy is required in many cases. The EpSSG NRSTS 2005 study was the first prospective protocol tailored specifically to NRSTS. Together with the ARST0332 study developed by the North-American Soft Tissue Sarcoma Committee of the Children's Oncology Group (COG), the EpSSG NRSTS 2005 study currently represents the benchmark for these tumors, establishing risk-adapted standards of care. The EpSSG has developed common treatment recommendations for the large group of adult-type NRSTS (including synovial sarcoma), and specific treatment recommendations for other particular adult-type histologies (ie, alveolar soft-part sarcoma, clear cell sarcoma and dermatofibrosarcoma protuberans); other highly malignant tumors with a biology and clinical behavior differing from those of adult-type NRSTS (ie, rhabdoid tumors and desmoplastic small round cell tumor); and soft tissue tumors of intermediate malignancy (ie desmoid-type fibromatosis, inflammatory myofibroblastic tumors, and infantile fibrosarcoma). New effective drugs are needed for patients whose NRSTS carries the worst prognosis, ie, those with unresectable tumors, metastases at diagnosis, or relapsing disease. Progress in this area relies on our ability to develop international integrated prospective collaborations, both within existing pediatric oncology networks and, importantly, between the communities of specialists treating pediatric and adult sarcoma.

Malignant Peripheral Nerve Sheath Tumors-A Comprehensive Review of Pathophysiology, Diagnosis, and Multidisciplinary Management

Malignant peripheral nerve sheath tumors (MPNSTs) are aggressive soft tissue sarcomas (STS) with nerve sheath differentiation and a tendency to metastasize. Although occurring at an incidence of 0.001% in the general population, they are relatively common in individuals with neurofibromatosis type 1 (NF1), for whom the lifetime risk approaches 10%. The staging of MPNSTs is complicated and requires close multi-disciplinary collaboration. Their primary management is most often surgical in nature, with non-surgical modalities playing a supportive, necessary role, particularly in metastatic, invasive, or widespread disease. We, therefore, sought to provide a comprehensive review of the relevant literature describing the characteristics of these tumors, their pathophysiology and risk factors, their diagnosis, and their multi-disciplinary treatment. A close partnership between surgical and medical oncologists is therefore necessary. Advances in the molecular characterization of these tumors have also begun to allow the integration of targeted RAS/RAF/MEK/ERK pathway inhibitors into MPNST management.

Treatment at Specialized Cancer Centers Is Associated with Improved Survival in Adolescent and Young Adults with Soft Tissue Sarcoma

Background: Soft tissue sarcomas (STS) are a heterogeneous group of tumors whose management benefits from a multidisciplinary therapeutic approach. Published data suggest that cancer treatment at a specialized cancer center (SCC) can improve survival in other cancers. Therefore, we examined the impact of the location of treatment on survival in children and adolescents and young adults (AYAs) with STS. Methods: We performed a population-based analysis of children and AYAs hospitalized within 1 year of diagnosis with first primary STS (2000-2014) using the California Cancer Registry linked with hospitalization data. Patients were categorized based on receiving all inpatient treatments at a SCC versus part/none. Multivariable Cox proportional hazards regression identified factors associated with overall and STS-specific survival by age group. Results are presented as adjusted hazard ratios (HRs) and 95% confidence intervals (CIs). Results: Of the 1,674 patients with STS, 142 were children (0-14) and 1,532 were AYAs (15-39) and 89.4% and 40.4% received all inpatient treatments at a SCC, respectively. Overall, the 5-year survival was improved for patients who received all inpatient care at a SCC (59.8% vs. those who received part/none, 50.7%). Multivariable regression analysis found that having all treatments at a SCC was associated with better overall survival (HR, 0.79, CI: 0.65-0.95) in AYAs, but not in children. Conclusions: Our findings demonstrate that treatment for STS at a SCC is associated with better survival in AYAs. Eliminating barriers to treatment of AYAs with STS at SCCs could improve survival in this population.

Synovial Sarcoma in Children, Adolescents, and Young Adults: A Report From the Children's Oncology Group ARST0332 Study

PURPOSE

Synovial sarcoma (SS) is the second most common malignant soft tissue tumor in children. ARST0332 evaluated a risk-based treatment strategy for young patients with soft tissue sarcoma designed to limit therapy for low-risk (LR) disease and to test neoadjuvant chemoradiotherapy for unresected higher-risk disease.

METHODS

Newly diagnosed patients with SS age < 30 years were assigned to four treatment arms based on disease features: A (surgery only), B (55.8 Gy radiotherapy [RT]), C (ifosfamide and doxorubicin [ID] chemotherapy plus 55.8 Gy RT), and D (neoadjuvant ID and 45 Gy RT, then surgery and RT boost based on margins followed by adjuvant ID). Patients treated in Arms A and B were considered LR, arms C and D without metastases as intermediate-risk (IR), and those with metastases as high-risk (HR).

RESULTS

Of the 146 patients with SS enrolled, 138 were eligible and evaluable: LR (46), IR (71), and HR (21). Tumors were 80% extremity, 70% > 5 cm, 70% high-grade, 62% invasive, 95% deep, and 15% metastatic. Treatment was on arm A (29.7%), B (3.6%), C (16.7%), and D (50%). There were no toxic deaths and four unexpected grade 4 adverse events. By risk group, at a median follow-up of 6.8 years, estimated 5-year event-free survival was LR 82%, IR 70%, and HR 8%, and overall survival was LR 98%, IR 89%, and HR 13%. After accounting for the features that defined risk category, none of the other patient or disease characteristics (age, sex, tumor site, tumor invasiveness, and depth) improved the risk stratification model.

CONCLUSION

The risk-based treatment strategy used in ARST0332 produced favorable outcomes in patients with nonmetastatic SS relative to historical controls despite using RT less frequently and at lower doses. The outcome for metastatic SS remains unsatisfactory and new therapies are urgently needed.

Paediatric non-rhabdomyosarcoma soft tissue sarcomas: the prospective NRSTS 2005 study by the European Pediatric Soft Tissue Sarcoma Study Group (EpSSG)

BACKGROUND

A standardised approach to treatment of paediatric non-rhabdomyosarcoma soft tissue sarcomas (NRSTS), which account for about 4% of childhood cancers, is still lacking. We report the results of the NRSTS 2005 protocol developed specifically by the European Pediatric Soft Tissue Sarcoma Study Group (EpSSG) to determine a risk-adapted multimodal standard of care for this group of tumours.

METHODS

The EpSSG NRSTS 2005 study included two prospective, non-randomised, historically controlled trials (one on localised adult-type NRSTS and the other on localised synovial sarcoma) done at 100 academic centres and hospitals in 14 countries. Patients younger than 21 years with a pathologically proven diagnosis of synovial sarcoma or an adult-type NRSTS, no evidence of metastatic disease, no previous treatment other than primary surgery, and diagnostic specimens available for pathological review were included. Patients were stratified by surgical stage, tumour size, nodal involvement, tumour grade (for adult-type NRSTS), and tumour site (for synovial sarcoma). Patients were then divided into four treatment groups: surgery alone, adjuvant radiotherapy, adjuvant chemotherapy (with or without radiotherapy), or neoadjuvant chemotherapy (with or without radiotherapy). The main chemotherapy regimen was ifosfamide (3·0 g/m² intravenously per day for 3 days) plus doxorubicin (37·5 mg/m² intravenously per day for 2 days); only ifosfamide (3·0 g/m² intravenously per day for 2 days) was given concomitantly with radiotherapy (delivered with three-dimensional conformal external beam technique, using conventional fractionation [1·8 daily fractions, 5 days per week] at a dose of 50·4 Gy or 54·0 Gy, to a maximum of 59·4 Gy). The number of chemotherapy cycles ranged from three to seven depending on the stage of the disease. The primary outcomes were event-free survival and overall survival. This study has been completed, and is registered under EudraCT, 2005-001139-31.

FINDINGS

Between May 31, 2005, and Dec 31, 2016, 1321 patients were enrolled, of whom 569 (206 with synovial sarcoma and 363 with adult-type NRSTS), with a median age of 12·6 years (IQR 8·2-14·9), were included in this analysis. With a median follow-up of 80·0 months (IQR 54·3-111·3) for the 467 patients alive, 5-year event-free survival was 73·7% (95% CI 69·7-77·2) and 5-year overall survival was 83·8% (95% CI 80·3-86·7). 5-year event-free survival was 91·4% (95% CI 87·0-94·4) and 5-year overall survival was 98·1% (95% CI 95·0-99·3) in the surgery alone group (n=250); 75·5% (46·9-90·1) and 88·2% (60·6-96·9) in the adjuvant radiotherapy group (n=17); 65·6% (54·8-74·5) and 75·8% (65·3-83·5) in the adjuvant chemotherapy group (n=93); and 56·4% (49·3-63·0) and 70·4% (63·3-76·4) in the neoadjuvant chemotherapy group (n=209). Reported severe adverse events included one case of generalised seizures (probably related to ifosfamide) and six cases of secondary tumours.

INTERPRETATION

Findings from the EpSSG NRSTS 2005 study help to define the risk-adapted standard of care for this patient population. Adjuvant treatment can be safely omitted in the low-risk population (classified here as the surgery alone group). Improving the outcome for patients with high-risk, initially resected adult-type NRSTS and those with initially unresectable disease remains a major clinical challenge.

FUNDING

Fondazione Città della Speranza.

Non-rhabdomyosarcoma soft-tissue sarcoma

Non-rhabdomyosarcoma soft-tissue sarcomas (NRSTS) comprise 4% of childhood cancers and consist of numerous histologic subtypes. Prognostic factors associated with poor outcome include high histologic grade, large tumor size, presence of metastases, and unresectability. Complete surgical resection is critical for the best oncologic outcomes and is prioritized in treatment algorithms. The use of radiation therapy (RT) and chemotherapy is based upon factors such as resectability, histologic grade, tumor size, and stage. North American and European trials are defining a risk-based approach to NRSTS to limit treatment-related toxicity and to maximize therapeutic efficacy. In this paper, we summarize the current roles of surgery, RT, and chemotherapy in NRSTS and describe ongoing research that is advancing the care of NRSTS patients.

Neurofibromatosis-associated malignant peripheral nerve sheath tumors in children have a worse prognosis: A nationwide cohort study

BACKGROUND

Malignant peripheral nerve sheath tumors (MPNST) are rare and aggressive non-rhabdomyoblastic soft-tissue sarcomas (NRSTS) in children. This study set out to investigate clinical presentation, treatment modalities, and factors associated with survival in pediatric MPNST using Dutch nationwide databases.

METHODS

Data were obtained from the Netherlands Cancer Registry (NCR) and the Dutch Pathology Database (PALGA) from 1989 to 2017. All primary MPNSTs were collected. Demographic differences were analyzed between adult and pediatric (age ≤18 years) MPNST. In children, demographic and treatment differences between neurofibromatosis type 1 (NF1) and non-NF1 were analyzed. A Cox proportional hazard model was constructed for localized pediatric MPNSTs.

RESULTS

A total of 70/784 MPNST patients were children (37.1% NF1). Children did not present differently from adults. In NF1 children, tumor size was more commonly large (> 5 cm, 92.3% vs 59.1%). Localized disease was primarily resected in 90.6%, and radiotherapy was administered in 37.5%. Non-NF1 children tended to receive chemotherapy more commonly (39.5% vs 26.9%). Overall, estimated five-year survival rates of localized NF1-MPNST was 52.4% (SE: 10.1%) compared with 75.8% (SE: 7.1%) in non-NF1 patients. The multivariate model showed worse survival in NF1 patients (HR: 2.98; 95% CI, 1.17-7.60, P = 0.02) and increased survival in patients diagnosed after 2005 (HR: 0.20; 95% CI, 0.06-0.69, P = 0.01). No treatment factors were independently associated with survival.

CONCLUSION

Pediatric MPNSTs have presentations similar to adult MPNSTs. In children, NF1 patients present with larger tumors, but are treated similarly to non-NF1 MPNSTs. In localized pediatric MPNST, NF1 is associated with worse survival. Promisingly, survival has increased for pediatric MPNSTs after 2005.

Systemic therapy in pediatric-type soft-tissue sarcoma

Soft-tissue sarcoma (sts) is rare and represents approximately 7% of cancers in children and in adolescents less than 20 years of age. Rhabdomyosarcoma (rms) is most prevalent in children less than 10 years of age and peaks again during adolescence (16-19 years of age). Multi-agent chemotherapy constitutes the mainstay of treatment for rms. In other non-rhabdomyosarcoma soft-tissue tumours, such as synovial sarcoma, evidence for routine use of chemotherapy is less robust, and alternative treatment options, including targeted agents and immunotherapy, are being explored. In this review, we focus on chemotherapy for pediatric-type rms and discuss the advances and challenges in systemic treatment for select non-rhabdomyosarcoma soft-tissue tumours in children and adolescents. We support an increasingly cooperative approach for treating pediatric and adult sts.

Treatment of malignant peripheral nerve sheath tumors in pediatric NF1 disease

BACKGROUND

Malignant peripheral nerve sheath tumors (MPNSTs) are rare yet highly aggressive soft tissue sarcomas. Children with neurofibromatosis type 1 (NF1) have a 10% lifetime risk for development of MPNST. Prognosis remains poor and survival seems worse for NF1 patients.

METHODS

This narrative review highlights current practices and pitfalls in the management of MPNST in pediatric NF1 patients.

RESULTS

Preoperative diagnostics can be challenging, but PET scans have shown to be useful tools. More recently, functional MRI holds promise as well. Surgery remains the mainstay treatment for these patients, but careful planning is needed to minimize postoperative morbidity. Functional reconstructions can play a role in improving functional status. Radiotherapy can be administered to enhance local control in selected cases, but care should be taken to minimize radiation effects as well as reduce the risk of secondary malignancies. The exact role of chemotherapy has yet to be determined. Reports on the efficacy of chemotherapy vary as some report lower effects in NF1 populations. Promisingly, survival seems to ameliorate in the last few decades and response rates of chemotherapy may increase in NF1 populations when administering it as part of standard of care. However, in metastasized disease, response rates remain poor. New systemic therapies are therefore desperately warranted and multiple trials are currently investigating the role of drugs. Targeted drugs are nevertheless not yet included in first line treatment.

CONCLUSION

Both research and clinical efforts benefit from multidisciplinary approaches with international collaborations in this rare malignancy.

A risk-based treatment strategy for non-rhabdomyosarcoma soft-tissue sarcomas in patients younger than 30 years (ARST0332): a Children's Oncology Group prospective study

BACKGROUND

Tumour grade, tumour size, resection potential, and extent of disease affect outcome in paediatric non-rhabdomyosarcoma soft-tissue sarcoma (NRSTS), but no risk stratification systems exist and the standard of care is poorly defined. We developed a risk stratification system from known prognostic factors and assessed it in the context of risk-adapted therapy for young patients with NRSTS.

METHODS

In this prospective study, eligible patients enrolled in 159 hospitals in three countries were younger than 30 years, had a Lansky (patients ≤16 years) or Karnofsky (patients >16 years) performance status score of at least 50, and a new diagnosis of a WHO (2002 criteria) intermediate (rarely metastasising) or malignant soft-tissue tumour (apart from tumour types eligible for other Children's Oncology Group studies and tumours for which the therapy in this trial was deemed inappropriate), malignant peripheral nerve sheath tumour, non-metastatic and grossly resected dermatofibrosarcoma protuberans, undifferentiated embryonal sarcoma of the liver, or unclassified malignant soft-tissue sarcoma. Each patient was assigned to one of three risk groups and one of four treatment groups. Risk groups were: low (non-metastatic R0 or R1 low-grade, or ≤5 cm R1 high-grade tumour); intermediate (non-metastatic R0 or R1 >5 cm high-grade, or unresected tumour of any size or grade); or high (metastatic tumour). The treatment groups were surgery alone, radiotherapy (55·8 Gy), chemoradiotherapy (chemotherapy and 55·8 Gy radiotherapy), and neoadjuvant chemoradiotherapy (chemotherapy and 45 Gy radiotherapy, then surgery and radiotherapy boost based on margins with continued chemotherapy). Chemotherapy included six cycles of ifosfamide 3 g/m² per dose intravenously on days 1-3 and five cycles of doxorubicin 37·5 mg/m² per dose intravenously on days 1-2 every 3 weeks with sequence adjusted on the basis of timing of surgery or radiotherapy. The primary outcomes were event-free survival, overall survival, and the pattern of treatment failure. Analysis was done per protocol. This study has been completed and is registered with ClinicalTrials.gov, NCT00346164.

FINDINGS

Between Feb 5, 2007, and Feb 10, 2012, 550 eligible patients were enrolled, of whom 21 were treated in the incorrect group and excluded from this analysis. 529 evaluable patients were included in the analysis: low-risk (n=222), intermediate-risk (n=227), high-risk (n=80); surgery alone (n=205), radiotherapy (n=17), chemoradiotherapy (n=111), and neoadjuvant chemoradiotherapy (n=196). At a median follow-up of 6·5 years (IQR 4·9-7·9), 5-year event-free survival and overall survival were: 88·9% (95% CI 84·0-93·8) and 96·2% (93·2-99·2) in the low-risk group; 65·0% (58·2-71·8) and 79·2% (73·4-85·0) in the intermediate-risk group; and 21·2% (11·4-31·1) and 35·5% (23·6-47·4) in the high-risk group, respectively. Risk group predicted event-free survival and overall survival (p<0·0001). No deaths from toxic events during treatment were reported. Nine patients had unexpected grade 4 adverse events (chemoradiotherapy group, n=2; neoadjuvant chemoradiotherapy group, n=7), including three wound complications that required surgery (all in the neoadjuvant chemoradiotherapy group).

INTERPRETATION

Pre-treatment clinical features can be used to effectively define treatment failure risk and to stratify young patients with NRSTS for risk-adapted therapy. Most low-risk patients can be cured without adjuvant therapy, thereby avoiding known long-term treatment complications. Survival remains suboptimal for intermediate-risk and high-risk patients and novel therapies are needed.

FUNDING

National Institutes of Health, St Baldrick's Foundation, Seattle Children's Foundation, American Lebanese Syrian Associated Charities.

Nonrhabdomyosarcoma soft tissue sarcoma (NRSTS) in pediatric and young adult patients: Results from a prospective study using limited-margin radiotherapy

BACKGROUND

Indications for and delivery of adjuvant therapies for pediatric nonrhabdomyosarcoma soft tissue sarcoma (NRSTS) have been derived largely from adult studies; therefore, significant concern remains regarding radiation exposure to normal tissue. The authors report long-term treatment outcomes and toxicities for pediatric and young adult patients with high-grade NRSTS who were treated on a prospective trial using limited-margin radiotherapy.

METHODS

Sixty-two patients (ages 3-22 years) with predominantly high-grade NRSTS requiring radiation were treated on a phase 2 institutional study of conformal external-beam radiotherapy and/or brachytherapy using a 1.5-cm to 2-cm anatomically constrained margin. The estimated cumulative incidence of local failure, Gray's method estimated cumulative incidence of local failure, Kaplan-Meier method estimated survival, competing-risk regression model determined predictors of disease outcome, and toxicity was reported according to CTCAE v2.0.

RESULTS

At a median follow-up of 5.1 years (range, 0.2-10.9 years), 9 patients had experienced local failure. The 5-year overall cumulative incidence of local failure was 14.8% (95% confidence interval [CI], 7.2%-25%), and all but 1 local failure occurred outside the highest-dose irradiation volume. The 5-year Kaplan-Meier estimates for event-free and overall survival were 49.3% (95% CI, 36.3%-61.1%) and 67.9% (95% CI, 54.2%-78.3%), respectively. Multivariable analysis indicated that younger age was the only independent predictor of local recurrence (P = .004). The 5-year cumulative incidence of grade 3 or 4 late toxicity was 15% (95% CI, 7.2%-25.3%).

CONCLUSIONS

The delivery of limited-margin radiotherapy using conformal external-beam radiotherapy or brachytherapy provides a high rate of local tumor control without an increase in marginal failures and with acceptable treatment-related morbidity. Cancer 2017;123:4419-29. © 2017 American Cancer Society.

Low-grade Nonrhabdomyosarcoma Soft Tissue Sarcoma: What is Peculiar for Childhood

BACKGROUND

Nearly half of soft tissue sarcomas are nonrhabdomyosarcomas (NRSTSs). The low-grade (LG) form comprises a heterogenous group of diseases that rarely metastasize but are known for local recurrence.

AIM OF THE STUDY

The aim of the study was to retrospectively evaluate pediatric LG-NRSTS with regard to demography, survival, and factors affecting outcome in Egyptian patients.

PATIENTS AND METHODS

The study reviewed 66 NRSTS patients who presented to the Pediatric Oncology Department, National Cancer Institute, Cairo University, between January 2008 and December 2013.

RESULTS

Out of the reviewed cases 32 patients had LG tumors and were eligible for analysis. The male to female ratio was 1:1 and the median age was 7.5 years (range, 1 mo to 18 y). Desmoid fibromatosis (N=18) showed frequent local recurrence and nearly half of this group was alive without disease. No recurrence of the disease occurred in the nonfibromatosis group (n=14) and all patients were alive and free of disease. The 5-year overall survival was 88% for the entire group of study patients versus 45% for event-free survival. Tumors >5 cm in diameter and fibromatosis histology subtype were associated with lower EFS.

CONCLUSIONS

LG-NRSTS generally has good prognosis, with overall survival reaching 90%. However, aggressive fibromatosis usually runs a poorer course in the form of high incidence of local recurrence and lower survival rates. This needs to be further assessed in larger prospective studies including novel therapies in addition to the current conventional modalities.

Opportunities for Improvement in Pathology Reporting of Childhood Nonrhabdomyosarcoma Soft Tissue Sarcomas: A Report From Children's Oncology Group (COG) Study ARST0332

OBJECTIVES

Treatment of soft tissue tumors in young patients relies on the diagnostic information conveyed in the pathology report. We examined pathology reports from Children's Oncology Group ARST0332 for inclusion of data elements required in published guidelines.

METHODS

Pathology reports for 551 eligible patients were examined for required data elements defined by the College of American Pathologists, including tissue type, procedure, tumor site, tumor maximum diameter, macroscopic extent of tumor, histologic type, mitotic rate, extent of necrosis, tumor grade, margin status, use of ancillary studies, and pathologic stage.

RESULTS

Only 65 (12%) of 551 reports included all required data elements. Of reports containing synoptic templates, 57% were complete.

CONCLUSIONS

This study reveals significant opportunity to improve the quality of pathology reports in young patients with soft tissue tumors. Use of templates or checklists improves completeness of reports.

Non-rhabdomyosarcoma soft-tissue sarcomas in children: Contemporary appraisal and experience from a single centre

Nonrhabdmyosarcoma soft tissue sarcomas (NRSTS) include a cluster of different types of soft tissue sarcomas clubbed together due to the rarity of individual subtypes. The diagnostic accuracy is lately reinforced due to the availability of immunohistochemical and molecular markers. Surgery is the central modality of treatment since many of them are insensitive to chemotherapy. With the availability of rational risk stratification system, efforts are in progress to evaluate the role of neoadjuvant chemotherapy and radiotherapy to improve outcomes especially for the locally advanced disease. The survival remains dismal for metastatic disease. This review highlights the current status of NRSTS and also describes the experience from a single centre in treatment of NRSTS.

Injectable and Biodegradable pH-Responsive Hydrogels for Localized and Sustained Treatment of Human Fibrosarcoma

Injectable hydrogels are an important class of biomaterials, and they have been widely used for controlled drug release. This study evaluated an injectable hydrogel formed in situ system by the reaction of a polyethylene glycol derivative with α,β-polyaspartylhydrazide for local cancer chemotherapy. This pH-responsive hydrogel was used to realize a sol-gel phase transition, where the gel remained a free-flowing fluid before injection but spontaneously changed into a semisolid hydrogel just after administration. As indicated by scanning electron microscopy images, the hydrogel exhibited a porous three-dimensional microstructure. The prepared hydrogel was biocompatible and biodegradable and could be utilized as a pH-responsive vector for drug delivery. The therapeutic effect of the hydrogel loaded with doxorubicin (DOX) after intratumoral administration in mice with human fibrosarcoma was evaluated. The inhibition of tumor growth was more obvious in the group treated by the DOX-loaded hydrogel, compared to that treated with the free DOX solution. Hence, this hydrogel with good syringeability and high biodegradability, which focuses on local chemotherapy, may enhance the therapeutic effect on human fibrosarcoma.

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.

New concepts for the treatment of pediatric nonrhabdomyosarcoma soft tissue sarcomas

Nonrhabdomyosarcoma soft tissue sarcomas form a group of rare tumors with a different biology and clinical behavior. The recently established European Pediatric Soft Tissue Sarcoma Study Group is organizing a new study devoted specifically to these tumors that were formerly treated according to the principles derived from experience with rhabdomyosarcoma, which is a clearly distinct entity. The new study includes two prospective trials, one for synovial sarcoma and the other for adult-type nonrhabdomyosarcoma soft tissue sarcomas. While surgery remains the mainstay of treatment, the role of adjuvant therapy is not yet clear and our understanding of the biology and natural history of nonrhabdomyosarcoma soft tissue sarcomas is still incomplete. This review presents the latest data on nonrhabdomyosarcoma soft tissue sarcoma treatment and outcome, and the rationale behind a risk-adapted treatment program that investigates the role of full-dose ifosfamide-doxorubicin chemotherapy in improving the response rate of patients with unresectable disease, the chances of avoiding adjuvant chemotherapy in low-risk synovial sarcomas, and the possible role of chemotherapy in high-risk adult-type soft tissue sarcomas.

Treatment options for children with nonrhabdomyosarcoma soft tissue sarcoma

Nonrhabdomyosarcoma soft tissue sarcomas account for approximately 40% of all soft tissue sarcomas in children. Although these tumors are typically grouped together, individual tumor types with different biological characteristics have been found that may impact on the optimal therapy for each type of sarcoma in the future. Most of the current information regarding this tumor comes from the adult literature. Wide local excision appears to provide the best chance of cure. Future studies are needed to determine which adjuvant therapies are most useful in improving local control and overall survival in the different subsets of patients.

Pediatric transoral robotic surgery for oropharyngeal malignancy: a case report

The treatment of oropharyngeal malignancy is associated with numerous functional morbidities. Transoral robotic surgery has been used with increased frequency in adult oropharyngeal malignancy. The benefits include decreased surgical morbidity and improved functional outcomes. Use of transoral robotic has been limited in children. This case represents our experience with a 17-month old child who was diagnosed with a high-grade undifferentiated sarcoma of the soft palate. She was able to be successfully treated with transoral robotic surgery as a part of her multimodal therapy, representing the first case of transoral robotic surgery for an oropharyngeal malignancy in a young child.

Synovial sarcoma presenting with huge mediastinal mass: a case report and review of literature

Background

Synovial sarcoma presenting in the mediastinum is exceedingly rare. Furthermore, data addressing optimal therapy is limited. Herein we present a case where an attempt to downsize the tumor to a resectable state with chemotherapy was employed.

Case presentation

A 32 year female presented with massive pericardial effusion and unresectable huge mediastinal mass. Computed axial tomography scan - guided biopsy with adjunctive immunostains and molecular studies confirmed a diagnosis of synovial sarcoma. Following three cycles of combination Ifosfamide and doxorubicin chemotherapy, no response was demonstrated. The patient refused further therapy and had progression of her disease 4 months following the last cycle.

Conclusion

Synovial sarcoma presenting with unresectable mediastinal mass carry a poor prognosis. Up to the best of our knowledge there are only four previous reports where primary chemotherapy was employed, unfortunately; none of these cases had subsequent complete surgical resection. Identification of the best treatment strategy for patients with unresectable disease is warranted. Our case can be of benefit to medical oncologists and thoracic surgeons who might be faced with this unique and exceedingly rare clinical scenario.

Randomized comparison of intensified six-drug versus standard three-drug chemotherapy for high-risk nonmetastatic rhabdomyosarcoma and other chemotherapy-sensitive childhood soft tissue sarcomas: long-term results from the International Society of Pediatric Oncology MMT95 study

PURPOSE

MMT95 was the fourth of a series of International Society of Pediatric Oncology (SIOP) collaborations for children with high-risk nonmetastatic soft tissue sarcoma (STS). The principal objective was to explore survival advantage for an intensified chemotherapy strategy in a randomized trial.

PATIENTS AND METHODS

From July 1995 to June 2003, 457 previously untreated patients with incompletely resected embryonal rhabdomyosarcoma (RMS), undifferentiated sarcoma, and soft tissue primitive neuroectodermal tumor at all sites except paratesticular, vagina, and uterus, or with alveolar RMS were randomly assigned to receive either ifosfamide, vincristine, and dactinomycin (IVA) or a six-drug combination (IVA plus carboplatin, epirubicin, and etoposide) both delivered over 27 weeks. Cumulative doses were as follows: ifosfamide 54 g/m(2) (both arms), epirubicin 450 mg/m(2), etoposide 1,350 mg/m(2) (six-drug regimen). Poor responders after three courses of IVA were to be switched to the other arm. Delivery of radiotherapy was determined according to site and/or response to chemotherapy with or without surgery.

RESULTS

Overall survival (OS) for all patients was 81% (95% CI, 77% to 84%) at 3 years. No significant difference in outcome in either OS or event-free survival was noted between the two arms (3-year OS: 82% [95% CI, 76% to 86%] for IVA and 80% [95% CI, 74% to 85%] for the six-drug arm). Toxicity was significantly greater (infection, myelosuppression, and mucositis) in the six-drug arm. Overall burden of local therapy was consistent with data from previous SIOP studies and showed no difference between the two chemotherapy regimens.

CONCLUSION

Intensification of chemotherapy for nonmetastatic RMS and other chemotherapy-sensitive STS provides no survival advantage or reduction in the intensity of local therapy and adds toxicity.

Definitive radiotherapy for unresectable pediatric and young adult nonrhabdomyosarcoma soft tissue sarcoma

BACKGROUND

Few published articles describe outcomes following definitive radiation for unresectable pediatric and young adult nonrhabdomyosarcoma soft tissue sarcoma (NRSTS). The purpose of this study is to evaluate the prognostic factors, outcomes, and complications in patients age 30 years or younger with NRSTS treated at the University of Florida from 1973 to 2002.

PROCEDURE

Nineteen pediatric and young adult patients with NRSTS were treated with radiotherapy after biopsy. Thirteen patients had high-grade tumors. The median age at radiotherapy was 19.6 years; the median dose was 55.2 Gy. Twelve patients received chemotherapy. Prognostic factors for local recurrence, distant metastases, and survival were analyzed.

RESULTS

Median follow-up was 2.6 years. The 5-year local-control rate was 40%. Nine out of 13 local failures occurred in the absence of metastatic disease. All patients with local failures died of their cancer, and 8 patients died without evidence of distant metastases. There was a trend toward improved local control with low/intermediate-grade tumors. Freedom from distant metastases at 5 years was 68%. Fourteen patients died of their disease. The 5-year overall survival was 37%. There was one grade 4 complication based on NCI Common Terminology Criteria for Adverse Events version 3.

CONCLUSION

Young patients with unresectable NRSTS have a poor outcome thereby justifying current study efforts focused on treatment intensification. By demonstrating that all patients with local recurrence died of disease and more than half of these deaths occurred in the absence of distant spread, these results suggests that improved means of local control may translate into improvement in survival.

Adjuvant radiotherapy for pediatric and young adult nonrhabdomyosarcoma soft-tissue sarcoma

PURPOSE

To evaluate the prognostic factors, outcomes, and complications in patients aged ≤30 years with resectable nonrhabdomyosarcoma soft-tissue sarcoma treated at the University of Florida with radiotherapy (RT) during a 34-year period.

METHODS AND MATERIALS

A total of 95 pediatric or young adult patients with nonrhabdomyosarcoma soft-tissue sarcoma were treated with curative intent with surgery and RT at the University of Florida between 1973 and 2007. The most common histologic tumor subtypes were synovial sarcoma in 22 patients, malignant fibrous histiocytoma in 19, and malignant peripheral nerve sheath tumor in 11 patients. The mean age at RT was 22 years (range, 6-30). Of the 95 patients, 73 had high-grade tumors; 45 had undergone preoperative RT and 50 postoperative RT. The prognostic factors for survival, local recurrence, and distant recurrence were analyzed.

RESULTS

The median follow-up was 7.2 years (range, 0.4-30.5). The actuarial 5-year local control rate was 88%. A microscopically negative margin was associated with superior local control. Although 83% of local recurrence cases initially developed in the absence of metastases, all patients with local failure ultimately died of their disease. The actuarial estimate of 5-year overall survival and disease-free survival was 65% and 63%, respectively. Of all the deaths, 92% were disease related. An early American Joint Committee on Cancer stage, tumor<8 cm, and the absence of neurovascular invasion were associated with superior disease-free survival. The National Cancer Institute Common Toxicity Criteria, version 3, Grade 3-4 treatment complication rate was 9%. No secondary malignancies were observed.

CONCLUSION

In the present large single-institution study, we found positive margins and locally advanced features to be poor prognostic factors for both local progression and survival. The results from the present study have helped to characterize the therapeutic ratio of RT in pediatric and young adult sarcoma patients and have provided a basis for identifying high-risk patients for whom treatment intensification might be justified.

Non-metastatic unresected paediatric non-rhabdomyosarcoma soft tissue sarcomas: results of a pooled analysis from United States and European groups

BACKGROUND

Non-rhabdomyosarcoma soft tissue sarcomas (NRSTS) with initially unresected tumours represent a particular subset of patients with a poor outcome. Various international research groups pooled their data in a joint study in order to investigate prognostic variables and treatment modalities.

METHODS

The study population consisted of 304 patients <21 years old treated between 1980 and 2005 using a multimodality therapeutic strategy.

RESULTS

Synovial sarcoma and malignant peripheral nerve sheath tumour (MPNST) were the most frequent histotypes. Most patients received initial chemotherapy: major responses were recorded in 41% and minor in 16% of cases. Overall survival (OS) was 60.0% and 51.5% at 5 and 10 years, respectively, and it was significantly associated with patient's age, histological subtype, tumour site and size, quality of delayed surgical resection, radiotherapy administration and response to induction chemotherapy. MPNST associated to neurofibromatosis type 1 was the tumour type with the worst rate of response to chemotherapy and the worst outcome.

CONCLUSIONS

In unresected NRSTS patients, radiotherapy and delayed surgery are of crucial importance. Patients who respond to chemotherapy have better chance of survival. However, given the relatively poor prognosis, research on intensive multimodal treatment approaches and novel strategies is warranted.

VEGF blockade decreases the tumor uptake of systemic oncolytic herpes virus but enhances therapeutic efficacy when given after virotherapy

Effective therapies for metastatic sarcomas remain elusive. Oncolytic viruses have shown promise as anticancer agents, but their access to metastatic sites following systemic delivery is low. As systemic delivery of small-molecule chemotherapy is enhanced by previous treatment with antiangiogenic agents because of changes in intravascular-to-tumor interstitial pressure, we sought to determine whether antiangiogenic pretreatment increases the antitumor efficacy of systemic virotherapy by increasing virus uptake into tumor. Virus biodistribution and antitumor effects were monitored in tumor-bearing mice given antihuman vascular endothelial growth factor (VEGF) or antimouse VEGFR2 before or after an intravenous (i.v.) injection of virus. Without pretreatment, the average virus titers in the tumor samples amplified 1700-fold over 48 h but were undetectable in other organs. After antiangiogenic treatment, average virus titers in the tumor samples were unchanged or in some cases decreased up to 100-fold. Thus, antiangiogenic pretreatment failed to improve the tumor uptake of systemic oncolytic herpes simplex virus (oHSV), in contrast to previously reported enhanced uptake of small molecules. Superior tumor control because of the combined effects of virus and anti-VEGF was seen most dramatically when anti-VEGF was given after virus. Our data suggest that i.v. oHSV can treat distant sites of disease and can be enhanced by antiangiogenic therapy, but only when given in the proper sequence.

Grading of nonrhabdomyosarcoma soft tissue sarcoma in children and adolescents: a comparison of parameters used for the Fédération Nationale des Centers de Lutte Contre le Cancer and Pediatric Oncology Group Systems

BACKGROUND

Two systems for grading soft tissue sarcoma are widely used currently: the National Cancer Institute (NCI) and the Fédération Nationale des Centers de Lutte Contre le Cancer (FNCLCC) systems. Both were developed using cohorts of predominantly adult patients. The Pediatric Oncology Group (POG) system, based on the NCI system, was adapted for grading pediatric nonrhabdomyosarcoma soft tissue sarcoma (NRSTS). The applicability and prognostic utility of the FNCLCC system in pediatric NRSTS has not been assessed or compared with the POG system.

METHODS

Tumors from 130 patients with malignant NRSTS enrolled on 3 completed multi-institutional clinical trials were assessed. Of 130 tumors, 102 (78%) were localized and 28 (22%) metastatic. Of the localized tumors, 55 of 102 (54%) were >5 cm. The estimated 5-year event-free survival (EFS) for the entire group was 47%.

RESULTS

As expected, stage and tumor sizes were predictive of EFS (P < .001). Both systems were predictive of 5-year EFS (POG, P = .0095 and FNCLCC, P = .0075). Patients whose tumors received discrepant grades (POG-G3 vs FNCLCC-G2/G1) (n = 44) had an intermediate outcome between those with concordant (G3 [n = 44] or G1/G2 [n = 42]) grades on both systems (P = .0018). By multivariate analysis, the mitotic index was predictive of EFS, using a cutoff of 10 mitotic figures per 10 high-power fields (P < .001).

CONCLUSIONS

In conclusion, both FNCLCC and POG systems provide an adequate prognostic measure of outcome for pediatric NRSTS; albeit, a sizeable subset of cases with apparently intermediate prognosis was graded differently by the 2 systems. The mitotic index appears to be a key parameter in grading pediatric NRSTS.

Retrospective study of the surgical management and outcome of nonrhabdomyosarcoma soft tissue sarcomas of the groin and axilla in children

PURPOSE

The incidence of pediatric nonrhabdomyosarcoma soft tissue sarcomas (NRSTSs) of the groin and axilla is unknown, and the optimal surgical approach to these patients is unclear.

METHODS

We conducted a retrospective study of patients treated at St Jude Children's Research Hospital from January 1962 to March 2007 for NRSTSs of the groin and axilla. Demographic variables, tumor pathology, clinical management, and outcome were reviewed.

RESULTS

Of the 300 patients treated for NRSTSs, only 10 had tumors of the axilla or groin (6 of whom had synovial sarcoma). Surgical interventions included wide resection of the tumor (n = 7), marginal resection (n = 1), subtotal resection (n = 1), and biopsy only (n = 1). Six patients underwent lymph node sampling; all were negative for tumor. Short- and long-term surgical complications were rare. Four patients received adjuvant chemotherapy (n = 3) and/or radiotherapy (n = 2). At a median follow-up of 8.5 years, 7 of the 10 were surviving free of disease. Two of these patients died of tumor progression (1 with metastases at diagnosis and 1 with an unresectable tumor at diagnosis), and one patient who was free of NRSTS died of secondary breast carcinoma.

CONCLUSIONS

Pediatric NRSTSs of the axilla and groin are rare, but outcomes are similar to those of other patients with NRSTS. Wide local excision of the tumor with preservation of good limb function should be the surgical goal and may be sufficient therapy in some cases.

Herpes simplex virus oncolytic therapy for pediatric malignancies

Despite improving survival rates for children with cancer, a subset of patients exist with disease resistant to traditional therapies such as surgery, chemotherapy, and radiation. These patients require newer, targeted treatments used alone or in combination with more traditional approaches. Oncolytic herpes simplex virus (HSV) is one of these newer therapies that offer promise for several difficult to treat pediatric malignancies. The potential benefit of HSV therapy in pediatric solid tumors including brain tumors, neuroblastomas, and sarcomas is reviewed along with the many challenges that need to be addressed prior to moving oncolytic HSV therapy from the laboratory to the beside in the pediatric population.

Role of chemotherapy in pediatric nonrhabdomyosarcoma soft-tissue sarcomas

The definition of nonrhabdomyosarcoma soft-tissue sarcomas includes a varied group of malignant soft part tumors that can occur in childhood, but the majority are entities typically observed in adult age. Similar to their adult counterparts, pediatric nonrhabdomyosarcoma soft-tissue sarcomas are usually considered scarcely sensitive to chemotherapy, but treatment strategies for these tumors have changed to some degree in recent years, and multiple-modality treatments that also include chemotherapy have increasingly been attempted. Subsets of patients with specific histological subtypes and prognostic variables have been thought likely to benefit from chemotherapy. The recent development of new molecular treatment approaches to specific tumor targets may enable the current limits of systemic therapies to be overcome in the near future, possibly identifying specific agents tailored to each histotype. While awaiting these developments, however, a better use of standard chemotherapy may prove important in improving the cure rate for these patients.

Challenges in the recruitment of adolescents and young adults to cancer clinical trials

The adolescent and young adult (AYA) oncology population has seen inferior progress in cancer survival compared with younger children and older adults over the past 25 years. Previously, AYAs had the best survival rates due to the prevalence of highly curable diseases including Hodgkin lymphoma and germ cell tumors, yet today AYAs have inferior survival rates to children and some adult cohorts. Survival rates are particularly poor for AYA-specific diseases such as sarcomas. Research involving children and adults diagnosed with common malignancies such as acute lymphoblastic leukemia has resulted in improved survival rates. However, AYAs have not directly benefited from such research due to low rates of access to and accrual on clinical trials. AYAs are less likely to have insurance or access to healthcare, are more likely to see providers who are not part of research institutions, and are less likely to be referred to or to join clinical trials, all of which may contribute to worse outcomes. Few clinical trials target AYA-specific diseases, leading to little information regarding how these diseases behave and what role the host plays. Tumor samples for this population are underrepresented in national tumor banks. Coupled with the need for more clinical trials that focus on AYA-specific cancers, better collaboration between adult and pediatric cooperative groups as well as increased education among community oncologists and primary care providers will be needed to enhance participation in clinical trials with the goal to increase survival and improve quality of that survival.

Management of childhood malignant peripheral nerve sheath tumor

Malignant peripheral nerve sheath tumor (MPNST) is rare, but is one of the most frequent non-rhabdomyosarcoma soft-tissue sarcomas in the pediatric population. These tumors occur most frequently at axial sites and are characterized by local aggressiveness and a propensity to metastasize. They are often associated with neurofibromatosis type 1 (NF-1): the lifetime risk of patients with NF-1 developing MPNST has been estimated at 8-13%, compared with 0.001% in the general population. Because of the rarity of this tumor, little information is available on its clinical management, particularly in the pediatric age group. In a recent report on the clinical findings and treatment outcomes from a large number of children and adolescents with MPNST in an Italian and German series, less satisfactory overall outcomes than those for other pediatric sarcomas were described. Therefore, the approach to the treatment of patients with MPNST should be aggressive and risk adapted, and is necessarily complex. Patients should be referred to selected institutions with adequate experience in treating soft-tissue sarcomas, and with the multidisciplinary skills for enrolling patients in clinical trials. Surgical resection represents the mainstay of treatment, while the role of adjuvant treatment is not yet clear. Post-operative radiotherapy seems to have a role in improving local control, although the potential morbidity of irradiation should be taken into account, particularly when treating children. Although lack of local control is the major cause of treatment failure, MPNST may give rise to distant metastases. These tumors are usually considered as having uncertain chemosensitivity, but recent evidence suggests that there may be a role for chemotherapy in patients with a high-grade histology. For the near future, our hopes lie in the development of novel tailored therapies directed specifically against the molecular targets of the neoplastic cells: soft-tissue sarcomas seem particularly promising candidates for targeted therapy.

Nonrhabdomyosarcoma soft tissue sarcoma (NRSTS)

Nonrhabdmyosarcoma soft tissue sarcoma (NRSTS) is a heterogenous group of tumors analyzed as a unique group because of the rarity of each histopathological subtype. Initial information available has been obtained from adult series or pediatric case studies. Recent reports by several multi-center groups have been published that evaluated prognostic factors and treatment protocols. Established prognostic factors include tumor grade, invasiveness, size, and intergroup rhabdomyosarcoma study (IRS) group. Identification of sarcoma-specific chromosomal translocations has allowed for more accurate definitive diagnosis. Some may have prognostic significance and may offer as potential therapeutic targets. Surgery remained important, as many of the tumors are scarcely chemosensitive. With the development of multimodalities, surgical management has evolved over the years. Patients with localized unresectable disease are managed with surgery +/- radiotherapy with very good results. Localized unresectable disease is intermediate in behavior and prognosis. Patients are treated with neoadjuvant chemotherapy, +/- radiotherapy, followed by delayed surgical resection. Prognosis in patients with metastatic disease has been poor despite combination chemotherapy with surgical resection. The addition of ifosfamide and doxorubicin in the chemotherapy regimes has provided some improvement. With the lack of new active agents, we will depend on advances in molecular techniques to develop novel targeted therapies, better molecular markers and histology-specific trials to evaluate this group of tumors.

Synovial sarcoma in children. A single centre experience

Synovial sarcoma (SS) is a rare disease in the paediatric population, predominating in adolescents. Surgery remains the best treatment strategy for resectable cases. Adjuvant chemotherapy or radiotherapy can be used but have not proven efficacy. Metastatic disease and unsuccessful surgery are major prognostic factors. We describe four cases in children aged 7-13 years old. All of them were affected by SS of upper and lower limbs, and had satisfactory resections with different outcomes in spite of receiving diverse chemotherapy regimens. One of them is at the moment under treatment for relapse, two are disease-free and another died after metastatic disease.

New drugs for the treatment of metastatic or refractory soft tissue sarcomas in children

Children with relapsed, recurrent or metastatic sarcomas represent a therapeutic challenge for the pediatric oncologist. Strategies for the development of newer therapies for children with these sarcomas have, in the past, been histology-specific. For example, drug development in rhabdomyosarcoma has relied upon the preclinical xenograft model, whereas therapies for pediatric nonrhabdomyosarcomatous soft tissue sarcomas have mostly been derived from adult trials. The progress to date and the tools used in the treatment of advanced pediatric sarcomas will be summarized in this review.

Localized unresectable non-rhabdo soft tissue sarcomas of the extremities in pediatric age

BACKGROUND

Treatment of initially unresectable nonrhabdo soft tissue sarcomas (NRSTS) in pediatric age is debated, due to their different chemosensitivity. The authors objective was to evaluate clinical features and treatment results observed in a series of Italian patients over a 24-year period.

METHODS

Fifty-two patients age 8-18 years (median 8 years) were observed (1979-2002). Primary sites were on the lower limbs in 41 and on the upper limbs in 11 cases. Clinical TNM and surgical Intergroup Rhabdomyosarcoma Staging systems were adopted. Therapeutic guidelines recommended an initial biopsy plus neoadjuvant chemotherapy. Aggressive delayed surgery of residual disease, including compartmental resections, was recommended. Radiotherapy was suggested only for patients age > 3 years when surgery was incomplete or not feasible.

RESULTS

The evaluation was performed dividing the patients into two categories according to their chemosensitivity. Chemosensitive (CTs) sarcomas, 21: synovial sarcoma, 11; extraosseous Ewing sarcomas, 5; primitive peripheral neuroectodermic tumors, 5. Nonchemosensitive (CTns) sarcomas, 31: fibrosarcoma, 11; malignant peripheral nerve sheet tumors, 10; liposarcoma, 2; hemangiopericitoma adult type, 2; epithelioid sarcoma, 2; and alveolar soft part sarcoma, leiomyosarcoma, clear cell sarcoma, and sarcoma NOS, each 1. Nineteen of 21 patients with CTs-NRSTS were alive without disease: the 5-year overall survival (OS) and progression-free survival (PFS) were 94.4% and 79.3%, respectively; 23 of 31 patients with CTns-NRSTS were alive without disease: 5-year OS and PFS were 75.3% and 68.3%, respectively. Response to neoadjuvant chemotherapy was complete or partial in 10 of 20 evaluable CTs and in 8 of 26 evaluable CTns tumors. The achievement of complete delayed resection was particularly important for CTns-NRSTS. Tumor size < 5 cm, distal site, and tumor grading for CTns sarcomas were often linked to a favorable outcome; no conclusive results were detected concerning age of the patients or T status of the tumor.

CONCLUSIONS

Multidisciplinary treatment without mutilating procedures allowed the cure of most patients with CTs and CTns-NRSTS. Relapses were cured in several cases of CTs tumors, whereas almost all patients with relapsed CTns tumors died due to the high rate of metastatic spread.

The role of adjuvant chemotherapy in children and adolescents with surgically resected, high-risk adult-type soft tissue sarcomas

PURPOSE

This analysis evaluates whether adjuvant chemotherapy can be recommended for high-risk, surgically-resected, adult-type non-rhabdomyosarcoma soft tissue sarcomas (NRSTS) within the new European Pediatric Soft Tissue Sarcoma Study Group (EpSSG) protocol. The Italian and German Cooperative Groups reviewed their data-bases, analyzing patients classified as group I-II, with high-grade tumor (G3) larger than 5 cm in size.

METHODS

The analysis included 36 patients, and compared the clinical features and outcome of the group of 21 patients who received chemotherapy versus the group of 15 patients treated with local therapies only.

RESULTS

For the series as a whole, 5-year event-free survival (EFS), metastasis-free survival (MFS), and overall survival (OS) were 26.2%, 34.0%, and 37.5%, respectively. In patients treated with chemotherapy, MFS and OS were 49.5% and 41.5% (median time to relapse: 13 months). In patients who did not receive chemotherapy, MFS and OS were 0% and 23.8% (median time to relapse: 3 months).

CONCLUSION

The role of adjuvant chemotherapy in NRSTS is still uncertain, however, the current retrospective analysis showed that: (1) despite the globally good prognosis of grossly-resected cases, patients with G3 and large-size have a high-risk of metastatic spread, and (2) MFS appears to be better in patients who had chemotherapy. Based in part on these results, and in accordance with recent suggestions coming from the literature on adult sarcomas, the EpSSG NRSTS protocol will recommend adjuvant chemotherapy in high-risk surgically-resected patients.

Widespread intratumoral virus distribution with fractionated injection enables local control of large human rhabdomyosarcoma xenografts by oncolytic herpes simplex viruses

Novel methods of local control for sarcomas are needed. We investigated the antitumor effect of two related herpes simplex virus (HSV) mutants, NV1020 and NV1066, on human rhabdomyosracoma cells and xenografts. Cell death correlated with virus replication and apoptosis in cultured cells and tumors. Complete regression was seen in all tumors <250 mm(3) following a single injection, yet only half of tumors >250 mm(3) showed a complete response. Fractionation of the virus dose into five injection sites did not increase transduction efficiency, transgene expression, or virus production, but did yield more widespread intratumoral distribution. Despite the same total dose of virus, improved control of large tumors was seen using fractionated injections as all large tumors (500-700 mm(3)) had durable, complete regression. Our data suggest that oncolytic HSVs may be useful for local control of bulky rhabdomyosarcoma tumors and that fractionated virus administration results in a more widespread virus infection and better tumor control. Therefore, strategies to maximize intratumoral virus distribution at initial delivery should be sought.

Phase II Trial of Neoadjuvant Vincristine, Ifosfamide, and Doxorubicin With Granulocyte Colony-Stimulating Factor Support in Children and Adolescents With Advanced-Stage Nonrhabdomyosarcomatous Soft Tissue Sarcomas: A Pediatric Oncology Group Study

Purpose

To describe the response rate and survival of children and adolescents with unresected or metastatic nonrhabdomyosarcomatous soft tissue sarcomas (NRSTS) treated with vincristine, ifosfamide, and doxorubicin.

Patients and Methods

Between September 1996 and June 2000, 39 eligible patients received vincristine (1.5 mg/m2 weekly for 13 doses), ifosfamide (3 g/m2 daily for 3 days every 3 weeks for seven cycles), doxorubicin (30 mg/m2 daily for 2 days for six cycles), and mesna (750 mg/m2 for four doses after ifosfamide). Granulocyte colony-stimulating factor was administered daily (5 μg/kg) after each cycle of chemotherapy. Radiotherapy was administered from weeks 7 through 12.

Results

The median patient age at diagnosis was 11.7 years; the most common primary tumor site was lower extremity (36%); and synovial sarcoma was the predominant histology. More than three fourths of all tumors were 5 cm or greater at their largest diameters. The overall objective combined partial and complete response rate was 41% (95% CI, 25.7% to 56.7%). The estimated 3-year overall survival and progression-free survival rates (± standard deviation) for eligible patients were 59% ± 8.2% and 43.6% ± 7%, respectively. Patients with clinical group III disease had significantly better 3-year and progression-free survival rates compared with patients who presented with metastatic disease.

Conclusion

The vincristine, ifosfamide, and doxorubicin regimen was moderately active against pediatric NRSTS. Patients with synovial sarcoma had higher response rates than other patients, and patients with unresected disease had improved outcomes. Patients with metastatic disease continue to fare poorly, and newer approaches are indicated for these patients.

Sarcomas in Adolescents and Young Adults

Adolescents and young adults, caught between the traditionally binary medical systems for children and adults, may be treated variably, depending on which side of the dichotomy they find themselves. As a result, their unique needs may go unmet because they occupy the fringes of the more typical child and adult patient populations. Soft tissue sarcomas in adolescents and young adults are a case in point, spanning the gap between the two fields but focusing on neither. Increasing age seems to be a poor prognosticator for soft tissue sarcomas, but is probably only a marker for other biological variables, patient characteristics, and treatment differences. This article discusses the issues unique to the management of soft tissue sarcomas in this population, pointing out what age-specific data are known and what areas are ripe for collaborative research between medical and pediatric oncologists.

Adjuvant chemotherapy for the treatment of advanced pediatric nonrhabdomyosarcoma soft tissue sarcoma: the National Cancer Institute experience

BACKGROUND

The survival of children and adolescents with advanced (unresectable or metastatic) nonrhabdomyosarcoma soft tissue sarcoma (NRSTS) is poor. In order to clarify the role of combining chemotherapy with aggressive local control using surgery and/or radiation, we reviewed our institutional experience with the treatment of advanced pediatric NRSTS.

PROCEDURE

We reviewed the charts of all patients less than 21 years treated for an advanced NRSTS at the National Cancer Institute (NCI) between 1983 and 2003. Tumor pathology was confirmed and demographic, disease, and treatment data were abstracted. Survival was calculated using standard methods.

RESULTS

Of the 25 patients who were treated over the study period, 15 had metastatic disease and 10 had unresectable or incompletely resected disease at presentation. Twenty-one patients received chemotherapy consisting of the combination of vincristine, doxorubicin, cyclophosphamide, ifosfamide, and etoposide, and the remaining 4 received regimens that included doxorubicin. Twenty patients (80%) had a complete (5/25) or partial (15/25) response after chemotherapy alone. After the combination of chemotherapy and local control, 14 patients (56%) had a complete response (CR). The estimated 5-year overall and event-free survival (EFS) for all patients was 0.50 (standard error = 0.11) and 0.34 (standard error = 0.10), respectively.

CONCLUSIONS

The combination of chemotherapy with aggressive local control in this cohort of pediatric patients with advanced NRSTS yielded results comparable to those observed in patients with advanced sarcomas that are chemotherapy responsive. Prospective randomized trials are needed to quantify the contribution of chemotherapy and to determine the ideal regimen.