Synovial sarcoma: Do children do better?

Anti-Tumor Effect of Non-Thermal Atmospheric Pressure Plasma-Activated Medium on Synovial Sarcoma: An In Vitro and In Vivo Study

Background/Objective: Anti-tumor effects of plasma-activated medium (PAM) were demonstrated using various malignant tumors. However, the anti-tumor effect of PAM on synovial sarcoma remains unclear. Therefore, we aimed to investigate the anti-tumor effects of PAM on synovial sarcoma and its underlying mechanisms, focusing on the quantitative analyses of both intracellular reactive oxygen species (ROS) and cell apoptosis. Methods: The human synovial sarcoma cell line HS-SY-II was used to investigate the cell viability after PAM treatment. We investigated the anti-tumor effects and side effects of local PAM injection in a synovial sarcoma xenograft murine model. Moreover, we observed PAM-induced intracellular ROS accumulation and cell apoptosis and assessed the involvement of intracellular ROS in the anti-tumor effects of PAM using an intracellular ROS scavenger. Results: PAM significantly decreased the viability of synovial sarcoma cells compared with untreated Dulbecco's modified Eagle medium. Local PAM injection into a synovial sarcoma xenograft murine model significantly suppressed tumor growth, including tumor volume (p < 0.001) and weight (p = 0.031), without side effects. Regarding anti-tumor mechanisms, PAM induced significant cell apoptosis and intracellular ROS accumulation (p < 0.001). The intracellular ROS scavenger significantly inhibited the anti-tumor effect of PAM (p < 0.001). Conclusions: We confirmed the anti-tumor effects of PAM on synovial sarcoma in vitro and in vivo, as well as the absence of side effects. The underlying mechanism was suggested to involve cell apoptosis induced by intracellular ROS accumulation. Considering the various clinical issues associated with the existing treatments of synovial sarcoma, PAM is a promising new option.

Comparative analysis of bone and soft tissue vs. visceral synovial sarcoma: Demographic, clinical, and survival outcomes; a retrospective population-based study

BACKGROUND

Synovial sarcoma (SS) is typically diagnoses in young adults and usually appears in the extremities and soft tissues. However, it can sometimes arise in visceral organs. This study examines the differences in patient demographics, clinical features, and survival rates between soft tissue and visceral synovial sarcoma.

METHODS

We analyzed data from the Surveillance, Epidemiology, and End Results (SEER) database spanning 2000-2018. ANOVA (analysis of variance) was used to identify significant factors for multivariate analysis. Cox regression modeling was used to determine independent risk factors for survival.

RESULTS

Of the 2,776 SS patients included, the median age was 39.0 years, predominating male (53.0 %) and white (81.3 %). Bone and soft tissue sarcomas were more common, accounting for 86.4 % of cases (p-value<0.001), while the rest were diagnosed as visceral sarcomas. Visceral SS patients were typically older (p-value<0.001), male (56.8 %), and white (84.8 %). They also presented more frequently with distant metastasis (HR 3.8, 95 % CI, 2.4-6.1), had larger tumors on average (HR for tumors >10 cm: 2.9, 95 % CI, 2.0-4.1), and were less likely to undergo surgery (HR 0.4, 95 % CI, 0.3-0.6). Despite receiving multimodal treatments, including surgery, radiation, and/or chemotherapy, visceral SS patients exhibited poorer overall survival compared to their bone and soft tissue SS counterparts (p-value<0.001).

CONCLUSION

Visceral SS often presents in older patients with advanced-stage and larger tumor size as compared to bone and soft tissue SS, which likely contributes to poorer survival. Advanced age, regional spread, and larger tumor size were all found to worsen outcomes, while surgery and radiation were found to be protective factors.

Comprehensive treatment of primary pelvic synovial sarcoma: A 28-month follow-up case report and review of the literature

Background

Primary synovial sarcoma originating in the pelvis is an extremely rare malignancy, and only a few cases have been reported. Usually, the tumor is detected at an advanced stage, making treatment more difficult. Lacking high-quality research, there are no consensus guidelines for the systemic treatment of the disease.

Case presentation

We admitted a 32-year-old male patient with an MRI suggestive of an 8.2 × 7.7 x 8.9 cm mass in the pelvis with bleeding. After a comprehensive evaluation, the patient underwent surgery, and postoperative pathology suggested biphasic synovial sarcoma. Once the diagnosis was clear, the patient was treated with chemotherapy, radiotherapy, and targeted therapy. Unfortunately, the patient died due to a recurrence of pelvic synovial sarcoma with multiple metastases throughout the body, with a survival period of 28 months.

Conclusion

Synovial sarcoma, a highly malignant soft tissue tumor, and primary intrapelvic synovial sarcoma are even rarer, with a poor prognosis. Ultrasound, Computed Tomography, and MRI can help doctors detect the tumor at an early stage and treat it aggressively, especially with surgical treatment, which can effectively improve the survival rate. Combined with the course of diagnosis and treatment of this case, it is possible to deepen the understanding of primary pelvic synovial sarcoma and discuss appropriate treatment strategies for this rare disease.

Mediastinal monophasic synovial sarcoma with vertebral metastases: A case report

Mediastinal monophasic synovial sarcoma is a rare subtype that often lacks specific imaging characteristics, posing diagnostic challenges. This case report describes a mediastinal monophasic synovial sarcoma with vertebral metastasis, emphasizing imaging findings, differential diagnosis, and pathological features, thereby providing crucial support for accurate diagnosis and treatment planning.

Neoplastic and Non-neoplastic Soft Tissue Lesions Around the Knee

Neoplastic and non-neoplastic soft tissue masses around the knee are often incidental findings. Most of these lesions are benign with typical imaging characteristics that allow a confident diagnosis. However, some of these incidental neoplastic masses are characterized by morbidity and potential mortality. This review highlights the typical aspects of these lesions, facilitating a correct diagnosis.

Successful reconstruction using a buccal fat pad flap in misdiagnosed buccinators intramuscular synovial sarcoma: A case report

INTRODUCTION

Synovial sarcoma (SS) is a subtype of soft tissue sarcoma that primarily usually occurs in the lower extremities but rarely arises in the head and neck areas, including the oral cavity. Due to its variable presentation and similarity to benign masses in terms of age at onset, growth rate, and favorable outcomes, SS is often misdiagnosed as a benign tumor. However, it is a malignant tumor.

PATIENT CONCERNS

We report the case of intramuscular SS in the oral cavity. Initially, the lesion was clinically suspected as a benign mass but was ultimately confirmed as malignant SS.

DIAGNOSIS

Although histopathological examination is the first step in diagnosing SS, molecular testing to confirm the presence of SYT-SSX fusion can provide a definitive diagnosis when the histopathology is inconclusive. In this patient as well, the postoperative pathological report confirmed the diagnosis of biphasic SS, and molecular testing revealed positive SYT/SSX fusion.

THERAPEUTICS INTERVENTIONS

Following the recommendation of multidisciplinary care system, a wide excision was performed including the buccinators muscle, and reconstruction was performed using a buccal fat pad flap to prevent cheek depression.

OUTCOMES

On the final pathologic report, SS was removed margin-free, and there were no metastatic lymph nodes. No evidence of cheek dimpling was observed, and follow-up neck CT showed no significant changes in the lymph nodes. As a result of observation up to several months after surgery, there were no functional and aesthetic complications.

CONCLUSIONS

We report a successful case of intramuscular SS resection, initially misdiagnosed as a benign mass, using a buccal fat pad flap. We also highlight the importance of correctly diagnosing SS, especially in the craniofacial region where it can be mistaken for benign masses.

Enhancing Healthcare for Sarcoma Patients: Lessons from a Diagnostic Pathway Efficiency Analysis

Sarcomas, rare and with lower survival rates than common tumors, offer insights into healthcare efficiency via the analysis of the total interval of the diagnostic pathway, combining the patient interval (time between the first symptom and visit with a physician) and diagnostic interval (time between first physician visit and histological diagnosis). Switzerland's healthcare system, Europe's costliest, lacks research on treating rare conditions, like mesenchymal tumors. This study examines the total interval of the diagnostic pathway for optimization strategies. Analyzing a dataset of 1028 patients presented from 2018 to 2021 to the Swiss Sarcoma Board (MDT/SB-SSN), this retrospective analysis delves into bone sarcoma (BS), soft-tissue sarcoma (STS), and their benign counterparts. Demographic and treatment data were extracted from medical records. The patient interval accounted for the largest proportion of the total interval and secondary care interval for the largest proportion of the diagnostic interval. Age, grade, and localization could be elicited as influencing factors of the length of different components of the total interval. An increasing age and tumor size, as well as the axial localization, could be elicited as factors increasing the probability of sarcoma. The patient and secondary care interval (SCI) offer the greatest potential for optimization, with SCI being the bottleneck of the diagnostic interval. New organizational structures for care work-ups are needed, such as integrated practice units (IPU) as integral part of value-based healthcare (VBHC).

Synovial sarcoma: characteristics, challenges, and evolving therapeutic strategies

Synovial sarcoma (SS) is a rare and aggressive disease that accounts for 5%-10% of all soft tissue sarcomas. Although it can occur at any age, it typically affects younger adults and children, with a peak incidence in the fourth decade of life. In >95% of cases, the oncogenic driver is a translocation between chromosomes X and 18 that leads to the formation of the SS18::SSX fusion oncogenes. Early and accurate diagnosis is often a challenge; optimal outcomes are achieved by referral to a specialist center for diagnosis and management by a multidisciplinary team as soon as SS is suspected. Surgery with or without radiotherapy and/or chemotherapy can be effective in localized disease, especially in children. However, the prognosis in the advanced stages is poor, with treatment strategies that have relied heavily on traditional cytotoxic chemotherapies. Therefore, there is an unmet need for novel effective management strategies for advanced disease. An improved understanding of disease pathology and its molecular basis has paved the way for novel targeted agents and immunotherapies that are being investigated in clinical trials. This review provides an overview of the epidemiology and characteristics of SS in children and adults, as well as the patient journey from diagnosis to treatment. Current and future management strategies, focusing particularly on the potential of immunotherapies to improve clinical outcomes, are also summarized.

A rare case of perineal synovial sarcoma

Synovial sarcoma is a malignant mesenchymal neoplasm that is frequently misdiagnosed due to its slow growth and small size. This tumor presents as a nonspecific heterogeneous mass on cross-sectional imaging. Biopsy and histopathological assessments are required to differentiate synovial sarcoma from other sarcoma subtypes and to define the tumor grade. This article presents the case of a 17-year-old male patient with perineal synovial sarcoma.

Multidisciplinary management of recurrent synovial sarcoma of the chest wall

Background

Synovial sarcoma (SS) is part of soft tissue sarcomas (STS). An incidence between 5% to 10% is estimated. The origin is mesenchymal mainly affecting the extremities. Being even rarer at the chest level and vertebral body, representing around 1%. Histologically, it consists of 3 variants: monophasic, biphasic, and poorly differentiated. Surgical resection is a priority when it comes to multidisciplinary management. The prognosis of patients with SS over the years has improved markedly.

Purpose

Understand and evaluate the multidisciplinary management of SS considering that the SS has a lowe prevalence and highly malignancy.

Study Design

We present a case of a 31-year-old male who has a history of monophasic synovial sarcoma diagnosed in 2019 and underwent surgery. Patient came back after two years without symptoms and posterior to a control MRI we observed a local recurrence of SS.

Methods

The literature was reviewed with a focus on best clinical and surgical strategy for recurrence of SS.

Results

The patient recovered well with return to his normal daily activities. The review of the literature shows us the importance of the multidisciplinary management for the optimal clinical and surgical approach of SS recurrence.

Conclusions

SS represents a unique variant of STS, with malignant and metastatic potential. Being a rare pathology, an adequate multidisciplinary management is essential when providing optimal care for the patient.

Prognostic factors of the synovial sarcoma of the extremities: imaging does matter

OBJECTIVES

Synovial sarcomas (SS) of the extremities are rare soft tissue sarcomas that are more common in young adults. We deciphered the imaging phenotype of SS with the aim to determine if imaging could provide an incremental value to currently known prognostic factors (PF)-age and histological grade-to predict long-term overall survival (OS).

METHODS

This retrospective multicenter study included consecutive pediatric and adult patients with synovial sarcomas of the extremities from December 2002 to August 2020. Inclusion criteria were (i) a follow-up greater than 5 years and (ii) available pre-therapeutic MRI. A subset analysis included MRI and CT-scan. Clinical, pathological, and imaging variables were collected in all patients. The primary endpoint was to evaluate the association of these variables with OS using univariate and multivariate Cox regressions.

RESULTS

Out of 428 patients screened for eligibility, 98 patients (mean age: 37.1 ± 15.2 years) were included (MRI: n = 98/98, CT scan: n = 34/98; 35%). The median OS was 75.25 months (IQR = 55.50-109.12) and thirty-six patients (n = 36/98;37%) died during follow-up. The recurrence rate was 12.2% (n =12/98). SS lesions were mostly grade 2 (57/98; 58%). On MRI, SS had a mean long-axis diameter of 67.5 ± 38.3 mm. On CT scan, 44% (15/34) were calcified. Grade (hazard ratio [HR] = 2.71; 95%CI = 1.30-5.66; p = 0.008), size of the lesions evaluated on MRI (HR = 1.02; 95% CI = 1.01-1.03; p < 0.001), and calcifications on CT scan (HR = 0.10; 95% CI = 0.02-0.50; p = 0.005) were independent PF of OS.

CONCLUSIONS

This study demonstrated that imaging biomarkers can be used to predict long-term outcome in patients with SS. Strikingly, the presence of calcifications on CT scan is associated with favorable outcome and provides an incremental value over existing PF such as age, grade, and size.

KEY POINTS

• Beyond its diagnostic value, MRI is a pre-operative prognostic tool in synovial sarcomas of the extremities since the size of the lesion is an important prognostic factor. • Calcifications on CT scans are independently and significantly associated with prolonged overall survival.

Emerging targeted and cellular therapies in the treatment of advanced and metastatic synovial sarcoma

Synovial sarcoma is a soft tissue sarcoma accounting for approximately 1,000 cases per year in the United States. Currently, standard treatment of advanced and metastatic synovial sarcoma is anthracycline-based chemotherapy. While advanced synovial sarcoma is more responsive to chemotherapy compared to other soft tissue sarcomas, survival rates are poor, with a median survival time of less than 18 months. Enhanced understanding of tumor antigen expression and molecular mechanisms behind synovial sarcoma provide potential targets for treatment. Adoptive Cell Transfer using engineered T-cell receptors is in clinical trials for treatment of synovial sarcoma, specifically targeting New York esophageal squamous cell carcinoma-1 (NY-ESO-1), preferentially expressed antigen in melanoma (PRAME), and melanoma antigen-A4 (MAGE-A4). In this review, we explore the opportunities and challenges of these treatments. We also describe artificial adjuvant vector cells (aAVCs) and BRD9 inhibitors, two additional potential targets for treatment of advanced synovial sarcoma. This review demonstrates the progress that has been made in treatment of synovial sarcoma and highlights the future study and qualification needed to implement these technologies as standard of care.

Soft-tissue sarcoma in adolescents and young adults

Soft-tissue sarcoma is a rare cancer that accounts for approximately 1% of all malignant tumors. Although they occur in various age groups, soft-tissue sarcomas account for 8% of all malignant tumors developing in adolescents and young adults, suggesting that they are not rare in this age group. This study aimed to evaluate the clinical and pathological characteristics of soft-tissue sarcoma in adolescents and young adults. According to the Bone and Soft-Tissue Tumor Registry in Japan, myxoid liposarcoma is the most common type of soft-tissue sarcoma found in adolescents and young adults; alveolar soft part sarcoma, extraskeletal Ewing sarcoma, epithelioid sarcoma, clear cell sarcoma and synovial sarcoma occur predominantly in this age group among soft-tissue sarcomas. The analysis based on this registry demonstrated that age was not a prognostic factor for poor survival of soft-tissue sarcoma, although the prognosis in adolescents and young adults was better than that in older patients in the US and Scandinavia. Adolescent and young adult patients with soft-tissue sarcoma have age-specific problems, and a multidisciplinary approach to physical, psychological, and social issues is necessary to improve the management of these young patients both during and after treatment.

A rare incidence of primary Synovial Spindle Cell Sarcoma in a 46-year-old male, successfully managed by surgical intervention-A Case Report

INTRODUCTION AND IMPORTANCE

Synovial sarcoma (SS) is a rare form of Soft Tissue Sarcoma (STS) which results from the malignant proliferation of mesenchymal cells. Specific etiologies are not yet known, and its incidence rate ranges between 0.81 and 1.42 per 1 million individuals. Its gender-specific prevalence is almost the same between males and females and it is unique from other subtypes of STS in that it's slow growing and in almost half the cases, patients present with distant metastasis at the time of diagnosis.

CASE PRESENTATION

We present the case of a 46-year-old previously healthy male patient, who complained from a right lower extremity painless bulge, which began to be visibly noticeable by the patient 2 months prior to admission. There were no signs of allocated inflammation nor lower limb ischemia. Radiology revealed an irregular mass formation conformant with neoplasia.

CLINICAL DISCUSSION

Surgical resection of the mass along with synthetic graft replacement of the concomitant vascular bundle. Histopathological analysis of the resected mass revealed a monophasic synovial spindle cell sarcoma.

CONCLUSION

SS is a rare neoplasm poses a grave risk for patients due to its malignant pathophysiology and the wide margin of misdiagnoses. It is pivotal to set-up proper preoperative diagnostic guidelines for it and maintain high clinical suspicion so that we can bring down the high rates of the morbidity and mortality which ensue from this malignancy.

Synovial sarcomas: A single surgeon experience of 130 cases

Background

Synovial sarcoma is a rare malignant tumor that generally requires a multidisciplinary therapeutic approach. In this study we report the experience of a single surgeon, evaluating surgical and oncological outcomes of the cases he treated through his 30 years carrier.

Methods

We enrolled patients treated surgically between 1988 and 2018. Surgical and medical treatments, as well as surgical and oncological results, were investigated.

Results

One hundred and thirty cases were included. Surgical resection was carried out achieving wide margins in 90% of the cases. At their latest follow‐up, 76 patients were continuously disease free, 16 were no evidence of disease, and other 16 were alive with disease. Twenty cases were dead of disease and two dead of other causes. Twenty‐five patients (19%) had local recurrence of synovial sarcoma through their postoperative intercourse. Thirty‐seven patients (28%) were diagnosed with at least a metastasis during their follow‐up. The global survival of our population, at each patient's latest follow‐up, was 82%. Cases with tumor size above 5 cm had a significantly higher risk to develop metastasis (p = 0.002).

Conclusions

Synovial sarcoma is a threatening disease and represents a challenge for oncological physicians and surgeons. Early diagnosis and multidisciplinary approach are mandatory to limit the spread of synovial sarcomas, maximizing the effectiveness of surgery and the other treatments.

Patterns of care and outcomes of 417 patients with METAstatic SYNovial sarcoma (METASYN): real-life data from the French Sarcoma Group (FSG)

Background

Synovial sarcoma (SS) occurs in both adult and pediatric patients. The primary aim of this study is to describe the outcomes, prognostic factors, and treatment of patients with metastatic SS within a nationwide cohort.

Patients and methods

All pediatric and adult patients with metastatic SS are registered in the French Sarcoma Group database. Data were collected from the national database https://conticabase.sarcomabcb.org/ up to March 2020. Descriptive and comparative analyses were conducted using SAS 9.4 and Stata Special Edition 16.1 software.

Results

Between January 1981 and December 2019, 417 patients with metastatic SS from 17 French sarcoma centers were included, including 64 (15.3%) under the age of 26 years. Median age was 42.5 years (range 9-87 years). The metastases were synchronous (cohort 1) or metachronous (cohort 2) in 18.9% (N = 79) and 81.1% (N = 338) patients, respectively. Median overall survival (OS) from the date of metastasis was 22.3 months (95% confidence interval 19.7-24.1 months). First-line chemotherapy without ifosfamide and/or doxorubicin was unfavorable for progression-free survival and OS (P < 0.001). Concerning cohort 1, young age, surgery of the primary tumor, and single metastatic site were independent favorable prognostic factors for OS. In cohort 2, surgery within an expert French Sarcoma Group center, absence of chemotherapy in the perioperative setting, the lungs as a single metastatic site, time to first metastasis >12 months, local therapy, and ifosfamide in the first metastatic line were independent favorable prognostic factors.

Conclusions

The outcome of patients with metastatic SS is influenced by local treatment, management in reference centers, and cytotoxic treatments given in the perioperative and metastatic setting.

•

METASYN is the largest retrospective study on metastatic adult and pediatric SS.

•

This study confirms that surgery remains the mainstay for improving OS in reference centers.

•

METASYN emphasizes the importance of focal treatment of metastases for OS.

•

This study offers real-life results in a metastatic setting and is a useful support for developing new strategies.

Magnetic resonance imaging findings of synovial sarcoma in children: location-dependent differences

BACKGROUND

While overall survival for children is greater than that for adults, synovial sarcoma remains an aggressive neoplasm with a potentially poor prognosis, and its magnetic resonance imaging (MRI) findings in children are not well described.

OBJECTIVE

We aimed to characterize the spectrum of MRI findings of synovial sarcoma in children with respect to anatomical location and outcome.

MATERIALS AND METHODS

Children with histologically confirmed synovial sarcoma and preoperative MRI performed within the past 11 years (2009-2020) were included. Two radiologists retrospectively reviewed each MRI to categorize location, signal characteristics and associated findings. Chi-square and Fisher exact tests were used to assess associations with locations and outcomes.

RESULTS

This study included 23 children (13 girls, 10 boys; mean age: 12.7±4.2 years) with 7 axial, 8 proximal and 8 distal appendicular lesions. Kappa ranged from 0.53 to 1. MRI findings differed significantly between locations with axial lesions measuring larger (P=0.01) and more likely to contain fluid levels (P=0.02), triple sign (P=0.02), inhomogeneous signal (T1-weighted images, P=0.003; T2-weighted images, P=0.02, contrast-enhanced images, P=0.03) with all lesions containing partially solid composition (P=0.03). At a median follow-up of 14 months (interquartile range: 7-33 months), 39% relapsed. Predictors of relapse (P<0.05) included metastasis at presentation, larger lesions, axial lesions and MRI findings of fluid level, T1-weighted hyperintensity, inhomogeneous signal (T1- and T2-weighted images) and poorly circumscribed margins.

CONCLUSION

A significant association was found between location and MRI findings in our cohort of children with synovial sarcoma. Axial lesions were more likely to be larger, appear heterogeneous and be associated with a worse outcome.

The Biology of Synovial Sarcoma: State-of-the-Art and Future Perspectives

New molecular insights are being achieved in synovial sarcoma (SS) that can provide new potential diagnostic and prognostic markers as well as therapeutic targets. In particular, the advancement of research on epigenomics and gene regulation is promising. The concrete hypothesis that the pathogenesis of SS might mainly depend on the disruption of the balance of the complex interaction between epigenomic regulatory complexes and the consequences on gene expression opens interesting new perspectives. The standard of care for primary SS is wide surgical resection combined with radiation in selected cases. The role of chemotherapy is still under refinement and can be considered in patients at high risk of metastasis or in those with advanced disease. Cytotoxic chemotherapy (anthracyclines, ifosfamide, trabectedin, and pazopanib) is the treatment of choice, despite several possible side effects. Many possible drug-able targets have been identified. However, the impact of these strategies in improving SS outcome is still limited, thus making current and future research strongly needed to improve the survival of patients with SS.

The sarcoma diagnostic interval: a systematic review on length, contributing factors and patient outcomes

Sarcomas are rare and heterogeneous mesenchymal tumours of soft tissue or bone, making them prone to late diagnosis. In other malignancies, early diagnosis has an impact on stage of disease, complexity of therapeutic procedures, survival and health-related quality of life (HRQoL). Little is known about what length of diagnostic interval should be considered as delay in patients with bone (BS) or soft tissue sarcomas (STS). To quantify total interval (defined as time from first symptom to histological diagnosis) and its components, identify contributing factors to its length and determine the impact on patients’ outcome in terms of mortality and HRQoL. A systematic review was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Seventy-six articles out of 2310 met the predefined inclusion criteria. Total intervals, varied broadly; 9–120.4 weeks for BS and 4.3–614.9 weeks for STS. Older age and no initial radiological examinations were contributing factors for a long interval in BS, while in STS results were conflicting. The impact of length of total interval on clinical outcomes in terms of survival and morbidity remains ambiguous; no clear relation could be identified for both BS and STS. No study examined the impact on HRQoL. The length of total interval is variable in BS as well as STS. Its effect on outcomes is contradictory. There is no definition of a clinically relevant cut-off point that discriminates between a short or long total interval. Prospero: CRD42017062492.

Is perioperative chemotherapy recommended in childhood and adolescent patients with synovial sarcoma? A systematic review

OBJECTIVE

Synovial sarcoma is the most common soft tissue sarcomas among childhood and adolescents, accounting for 8-10% of all soft tissue sarcoma. Synovial sarcoma is considered a relatively chemosensitive tumor compared with other soft tissue sarcomas. However, the role of perioperative chemotherapy in synovial sarcoma remains controversial. The purpose of this systematic review is to evaluate the role of perioperative chemotherapy in childhood and adolescent patients with synovial sarcoma.

METHODS

We evaluated studies published between 1 January 1990 and 31 December 2017. The following databases were searched: MEDLINE, Cochrane database (via PubMed) and Ichushi (in Japanese).

RESULTS

The search yielded 216 articles in English and Japanese. After the initial screening, based on the title and abstract, 160 articles were excluded. As a second screening, we then assessed the full text of the remaining 56 articles for eligibility. Finally, 10 articles were included in the systematic review. Surgical resection with R0 margin alone was recommended because of the excellent results of two prospective studies. Meta-analysis was performed using data from two retrospective studies of 261 patients. Perioperative chemotherapy did not have a significant effect on survival and event-free survival.

CONCLUSIONS

We weakly do not recommend perioperative chemotherapy in patients with non-metastatic synovial sarcoma ≤ 5 cm when R0 resection is acquired. There was no consensus concerning the role of perioperative chemotherapy in patients with synovial sarcoma > 5 cm or those with ≤5 cm who undergo R1 or R2 resection.

Synovial Sarcoma: A Clinical Review

Synovial sarcomas (SS) represent a unique subset of soft tissue sarcomas (STS) and account for 5–10% of all STS. Synovial sarcoma differs from other STS by the relatively young age at diagnosis and clinical presentation. Synovial sarcomas have unique genomic characteristics and are driven by a pathognomonic t(X;18) chromosomal translocation and subsequent formation of the SS18:SSX fusion oncogenes. Similar to other STS, diagnosis can be obtained from a combination of history, physical examination, magnetic resonance imaging, biopsy and subsequent pathology, immunohistochemistry and molecular analysis. Increasing size, age and tumor grade have been demonstrated to be negative predictive factors for both local disease recurrence and metastasis. Wide surgical excision remains the standard of care for definitive treatment with adjuvant radiation utilized for larger and deeper lesions. There remains controversy surrounding the role of chemotherapy in the treatment of SS and there appears to be survival benefit in certain populations. As the understanding of the molecular and immunologic characteristics of SS evolve, several potential systematic therapies have been proposed.

Primary Knee Intra-articular Synovial Sarcoma in Pediatric and Adolescent Patients

Synovial sarcoma (SS) arising within a knee joint is extremely rare, with 10 reported cases in pediatric and adolescent patients in English literature. Its rarity and nonspecific clinical and radiological features pose a diagnostic challenge. We present two cases of primary intra-articular SS of left knee to enhance awareness of this entity. One patient is a 17-year-old male complained of left knee pain and gait abnormality for 9 years. The other one is a 13-year-old female presented with left knee pain for one year. Both cases were clinically diagnosed as benign joint lesion and underwent biopsies. Histological examination, immunohistochemical staining and molecular study confirmed that both patients had primary intra-articular SS, monophasic spindle cell type. Intraarticular SS should be considered as a potential diagnosis with unexplained long-standing knee pain.

Treatment Concepts and Challenges in Nonrhabdomyosarcoma Soft Tissue Sarcomas

Pediatric nonrhabdomyosarcoma soft tissue sarcomas (NRSTSs) encompass a heterogeneous group of mesenchymal tumors with more than 50 histologic variants. The incidence of NRSTS is greater than rhabdomyosarcoma; however, each histologic type is rare. The treatment schema for all NRSTSs is largely surgical. The treatment is a risk-adapted approach based on tumor size, localization, tumor grade, and presence of metastases. Low-grade tumors are mainly managed by surgery alone, whereas for high-grade tumors a multimodal treatment concept is necessary. The multimodal treatment consists of tumor biopsy, chemotherapy, local treatment (surgery ± radiotherapy), and immunotherapy in selected conditions.

Synovial sarcoma disease characteristics and primary tumor sites differ between patient age groups: a report of the Cooperative Weichteilsarkom Studiengruppe (CWS)

BACKGROUND

Older age is associated with worse outcome in synovial sarcoma (SS) patients. Differences in disease presentation among distinct age groups, however, are currently unknown.

METHODS

SS patients < 21 years registered in consecutive CWS trials over the period of 1981-2018 were evaluated. Characteristics were analyzed according to age groups using the Fisher's exact test.

RESULTS

The study population included 432 SS patients. Disease characteristics differed according to age groups of children (0-12 years, n = 176), adolescents (13-16 years, n = 178), and young adults (17-21 years, n = 78). The proportion of invasive tumors (T2) was significantly higher in older patients: children 33%, adolescents 39% and young adults 54%, p = 0.009805. Similarly, the proportion of tumors > 10 cm was higher (13%, 21%, 31%; p = 0.005657) whereas conversely, the proportion of small tumors < 3 cm was lower in older patients (29%, 24%, 6%; p = 0.000104). The presence of metastases at first diagnosis was also highest in older patients (6%, 10%, 21%, p = 0.000963). Notably, the proportion of thigh tumors was higher in older patients (p = 0.04173), whereas the proportion of head-neck tumors was lower in older patients (p = 0.08896).

CONCLUSIONS

The rates of large, invasive tumors and the presence of metastases are significantly associated with older patient age. Localization to the thigh is more frequent in older patients.

DISCUSSION

The causes for these variations require further exploration.

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.

Synovial sarcoma mimicking a traumatic pseudoaneurysm in the upper extremity

Synovial sarcomas are a rare but aggressive malignancy that primarily affects young patients. Diagnosis is often difficult and delayed due to its insidious onset, heterogenous presentation and mimicry of other pathologies. We present the case of a patient with a history of a slow-growing left arm mass that arose after a traumatic fracture of the humerus. Multimodal imaging was undertaken and reported the mass as being consistent with a vascular malformation of the brachial artery. The patient underwent surgical repair of the artery and intraoperative biopsies confirmed a diagnosis of synovial sarcoma. This case highlights the importance of maintaining suspicion for soft-tissue sarcomas in young patients presenting with a mass, and demonstrates the way in which these tumours may mimic other pathologies both clinically and radiologically. Early referral to a specialist sarcoma centre is key for further investigative workup.

Epigenetic Targets in Synovial Sarcoma: A Mini-Review

Synovial Sarcomas (SS) are a type of Soft Tissue Sarcoma (STS) and represent 8-10% of all STS cases. Although SS can arise at any age, it typically affects younger individuals aged 15-35 and is therefore part of both pediatric and adult clinical practices. SS occurs primarily in the limbs, often near joints, but can present anywhere. It is characterized by the recurrent pathognomonic chromosomal translocation t(X;18)(p11.2;q11.2) that most frequently fuses SSX1 or SSX2 genes with SS18. This leads to the expression of the SS18-SSX fusion protein, which causes disturbances in several interacting multiprotein complexes such as the SWItch/Sucrose Non-Fermentable (SWI/SNF) complex, also known as the BAF complex and the Polycomb Repressive Complex 1 and 2 (PRC1 and PRC2). Furthermore, this promotes widespread epigenetic rewiring, leading to aberrant gene expression that drives the pathogenesis of SS. Good prognoses are characterized predominantly by small tumor size and young patient age. Whereas, high tumor grade and an increased genomic complexity of the tumor constitute poor prognostic factors. The current therapeutic strategy relies on chemotherapy and radiotherapy, the latter of which can lead to chronic side effects for pediatric patients. We will focus on the known roles of SWI/SNF, PRC1, and PRC2 as the main effectors of the SS18-SSX-mediated genome modifications and we present existing biological rationale for potential therapeutic targets and treatment strategies.