Synovial sarcoma: a multivariate analysis of prognostic factors in 112 patients with primary localized tumors of the extremity

Clinicopathological Profile and Survival Outcomes in Patients with Localised Extremity Synovial Sarcomas

AIMS

Synovial sarcoma is a rare but aggressive variant of soft-tissue sarcoma. Literature is sparse and reported mostly from the West. We analysed the clinical profiles and prognostic factors of extremity synovial sarcoma patients in order to study their clinical journey.

MATERIALS AND METHODS

This was a retrospective analysis. All patients with extremity synovial sarcoma treated between 1992 and 2020 were included. Patients with metastases at presentation were excluded. A descriptive analysis of demographic and clinicopathological features of patients undergoing limb salvage surgery (LSS) or amputation was carried out. Overall survival and disease-free survival were calculated for the entire cohort as well as for the LSS and amputation groups. Factors prognostic for survival were identified.

RESULTS

In total, 157 patients had localised extremity synovial sarcoma. Predominantly, young adults (median 31 years) and males (61%) were affected. Over 70% of patients presented after recurrence or unplanned surgeries. Sixty-seven per cent of tumours were >5 cm, 69% were deep and 23% involved bone. The limb salvage rate was 64%. In the LSS group, adjuvant radiotherapy and chemotherapy were given to 72% and 68% of patients, respectively. In the amputation group, 72% of patients received adjuvant chemotherapy. In a median follow-up of 59 months, 39.4% of patients had recurrences, the majority (61.2%) were systemic. Five-year overall survival and disease-free survival were 53.4% and 49.8%, respectively. Overall survival was 63.9% and 29.7% in the LSS and amputation groups, respectively. On multivariate analysis, tumour size, depth, omission of radiotherapy and bone invasion were found to be the adverse prognostic factors.

CONCLUSION

This is one of the largest studies on extremity synovial sarcoma. Mostly males and young adults were affected. The limb salvage rate was 64%, despite most being referred after unplanned surgery. Almost 70% of patients received radiotherapy and chemotherapy. Overall survival was inferior in the amputation group. Tumour size >5 cm, depth and bone invasion were negative, whereas adjuvant radiotherapy was a positive prognostic factor for survival. Chemotherapy had no impact on survival.

Multivariate evaluation of prognostic markers in synovial sarcoma

AIMS

Synovial sarcoma (SS) is an aggressive neoplasm but with varied clinical outcomes despite standard treatment protocols. Several clinicopathological features and immunohistochemical stains have been proposed as prognostic markers in SS. The aim of this study was to evaluate SS from a single institution for prognostically relevant clinicopathological and immunohistochemical factors.

METHODS

We identified a single-institution cohort of SS with follow-up. Clinical and pathological factors examined included age, sex, tumour location, AJCC (American Joint Committee on Cancer) stage, tumour size, grade and status of surgical margins. Immunohistochemical staining for p16, p53, RB1, MYC, PTEN (phosphatase and tensin homologue), β-catenin, MDM2 and Ki67 proliferative index was performed on tissue microarray. Cox proportional hazard model was used for multivariate assessment of overall survival (OS) and disease-free survival (DFS).

RESULTS

133 patients with SS met the inclusion criteria for our cohort, with 100 having complete dataset for all study covariates. On Cox regression multivariate analysis, location (axial vs extremity, p<0.001), AJCC stage (p<0.001), p16 expression (≥75%, p=0.021) were significantly associated with worse OS, whereas PTEN intensity (score 2, p<0.001) and p53 expression (null/≥75%, p=0.013) were correlated with improved OS. For DFS analysis, location (axial vs extremity, p=0.030), tumour size (≥5 cm, p=0.009) and MYC expression (≥33%, p=0.013) were associated with inferior outcome. Only PTEN intensity (score 2, p<0.001) correlated with improved DFS.

CONCLUSIONS

In reviewing numerous clinicopathological and immunohistochemical markers, this study shows that location, AJCC stage, p16, p53 and PTEN expression were prognostically significant in multivariate analysis for OS in a uniformly treated SS cohort. Location, tumour size, MYC and PTEN expression were significantly associated with DFS.

Localized Synovial Sarcoma: A Population-Based Analysis of Treatment Patterns and Survival

Purpose: Synovial sarcoma (SS) is a rare, high-grade soft tissue tumor that requires multidisciplinary and multimodal care with surgery, radiotherapy, and chemotherapy. We examined the impact of sociodemographic and clinical factors on treatment patterns and survival in localized SS patients. Methods: Adolescents and young adults (AYAs, 15-39 years) and older adults ("adults," ≥40 years) diagnosed with localized SS from 2000 to 2018 were identified in the California Cancer Registry. Multivariable logistic regression identified clinical and sociodemographic factors associated with receipt of chemotherapy and/or radiotherapy. Cox proportional hazards regression identified factors associated with overall survival (OS). Results are reported as odds ratios (ORs) and hazard ratios (HRs), respectively, with 95% confidence intervals (CIs). Results: More AYAs (n = 346) than adults (n = 272) received chemotherapy (47.7% vs. 36.4%) and radiotherapy (62.1% vs. 58.1%). Age at diagnosis, tumor size, treatment at National Cancer Institute-Children's Oncology Group (NCI-COG)-designated facilities, insurance status, and neighborhood socioeconomic status (SES) influenced treatment patterns. Among AYAs, treatment at NCI-COG-designated facilities was associated with receiving chemotherapy (OR 2.74, CI 1.48-5.07) and low SES was associated with worse OS (HR 2.28, 1.09-4.77). In adults, high SES was associated with receiving chemoradiotherapy (OR 3.20, CI 1.40-7.31), whereas public insurance was associated with decreased odds of chemoradiotherapy (OR 0.44, CI 0.20-0.95). With regard to treatment, absence of radiotherapy (HR 1.94, CI 1.18-3.20) was associated with worse OS in adults. Conclusion: In localized SS, both clinical and sociodemographic factors influenced treatment patterns. Further research should investigate how SES-related factors produce treatment disparities and identify interventions to improve treatment equity and outcomes.

Primary Gastric Synovial Sarcoma in a Young Male: a Rare Case Report and Review of Literature

We are reporting a rare case of primary gastric synovial sarcoma in a young male. Synovial sarcoma of the stomach is a very rare tumor. The common involved sites of occurrence of synovial sarcomas are upper and lower extremities. In the English literature, only 47 cases of primary synovial sarcoma of stomach have been reported. Spindle-shaped tumor cells are the basic content of synovial sarcomas with varying degrees of epithelial differentiation. The basic classification of synovial sarcoma depends on the histological pattern and the degree of differentiation and it is classified as monophasic, biphasic, and poorly differentiated. Synovial sarcoma presents with classical chromosomal translocation where they form fusion genes of SS18-SSX1, SS18-SSX2, and SS18-SSX4. Fluorescence in situ hybridization (FISH) and reverse transcription polymerase chain reaction (RT-PCR) are the molecular analysis techniques to detect these fusion genes. As the available literature support is limited, the role of adjuvant chemotherapy, radiation therapy, and intra-operative lymphadenectomy is still unclear. However, surgical resection with clear margin is the gold standard treatment.

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.

Tumor size and surgical margins are important prognostic factors of synovial sarcoma - A retrospective study

Background

Synovial Sarcoma (SS) is a rare soft tissue sarcoma. Mean time to get a SS diagnosis from the onset of symptoms is 10 years, furthermore, SS is associated with late metastasis. Surgery is the main treatment option, whose quality deeply affects SS outcomes, and it can be associated to preoperative or post-operative radiotherapy. Chemotherapy is considered very effective in Children, while in adults its efficacy is still under debate. The aim of this study was to investigate the oncologic results in SS treatment and to identify the risk factors for local and systemic control of the disease.

Methods

From 1994 to 2018, 211 patients affected by SS were treated in 3 Referral Centres of Orthopaedic Oncology. One hundred seventy-seven patients were included in the study, the median follow-up length was 96 months (5-374).

Results

Overall Survival on the Kaplan Meier Analyses was 80%, 70% and 56% at 5, 10 and 20 years. In multivariate analyses, OS correlated with tumour size and negative surgical margins. Chemotherapy use wasn't associated with better survival although patients who underwent CT had bigger and more aggressive tumours.

Conclusions

Our findings suggests that surgery with negative margins is the most important factor in Synovial Sarcoma. Adjuvant treatments as chemotherapy and radiation therapy didn't change the disease's course.

Clinical analysis of multimodal treatment for localized synovial sarcoma: A multicenter retrospective study

INTRODUCTION

Several prognostic factors for survival in synovial sarcoma have been proposed, but the role of adjuvant chemotherapy and radiotherapy is a matter of debate. The study aim was to clarify the effect of high-dose ifosfamide-containing chemotherapy and adjuvant radiotherapy for patients with localized synovial sarcoma.

MATERIALS AND METHODS

Five tertiary musculoskeletal oncology hospitals participated in this retrospective study. The records of the patient diagnosed with synovial sarcoma without metastasis at diagnosis from 1990 to 2011 have been collected and reviewed. Overall, distant failure-free, and local failure-free survivals were calculated, and prognostic factors for each survival were evaluated by performing univariate and multivariate analyses.

RESULTS

A total of 162 patients were enrolled in this study with a median follow-up period of 67 months (range, 5-267 months) for all surviving patients. The 5-year overall, distant failure-free, and local failure-free survival rates were 79.7%, 66.3%, and 98.4%, respectively. Univariate analyses demonstrated that high-dose ifosfamide-containing chemotherapy was significantly associated with better overall (p = 0.014) and distant failure-free survival (p = 0.0043) than that of low-dose or no ifosfamide-containing chemotherapy if we analyzed only patients with tumors >5 cm in size. Addition of radiotherapy was not a significant prognostic factor for overall survival in the univariate and multivariate analyses, but it did improve the overall survival of the patients with R1 resection (p = 0.053).

CONCLUSION

Patients with localized synovial sarcoma >5 cm in size had better overall and distant failure-free survival after receiving adjuvant chemotherapy containing high-dose ifosfamide comparing to low-dose or no ifosfamide-containing chemotherapy. The addition of adjuvant radiotherapy was beneficial for the patients who received R1 resection. Alternatively, adjuvant radiotherapy could be avoided for patients who achieved an R0 margin.

Characterisation of a Novel Cell Line (ICR-SS-1) Established from a Patient-Derived Xenograft of Synovial Sarcoma

Synovial sarcoma is a rare translocation-driven cancer with poor survival outcomes, particularly in the advanced setting. Previous synovial sarcoma preclinical studies have relied on a small panel of cell lines which suffer from the limitation of genomic and phenotypic drift as a result of being grown in culture for decades. Patient-derived xenografts (PDX) are a valuable tool for preclinical research as they retain many histopathological features of their originating human tumour; however, this approach is expensive, slow, and resource intensive, which hinders their utility in large-scale functional genomic and drug screens. To address some of these limitations, in this study, we have established and characterised a novel synovial sarcoma cell line, ICR-SS-1, which is derived from a PDX model and is amenable to high-throughput drug screens. We show that ICR-SS-1 grows readily in culture, retains the pathognomonic SS18::SSX1 fusion gene, and recapitulates the molecular features of human synovial sarcoma tumours as shown by proteomic profiling. Comparative analysis of drug response profiles with two other established synovial sarcoma cell lines (SYO-1 and HS-SY-II) finds that ICR-SS-1 harbours intrinsic resistance to doxorubicin and is sensitive to targeted inhibition of several oncogenic pathways including the PI3K-mTOR pathway. Collectively, our studies show that the ICR-SS-1 cell line model may be a valuable preclinical tool for studying the biology of anthracycline-resistant synovial sarcoma and identifying new salvage therapies following failure of doxorubicin.

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.

SYT-SSX1 enhances the invasiveness and maintains stem-like cell properties in synovial sarcoma via induction of TGF-β1/Smad signaling

Background

Synovial sarcoma (SS) is a type of soft tissue sarcoma (STS) of undetermined tissue origin, which is characterized by the recurrent pathognomonic chromosomal translocation t (X;18)(p11.2; q11.2). Studies have shown that SS is a malignant tumor originating from cancer stem cells or pluripotent mesenchymal stem cells and may be related to fusion genes. In addition, some studies have indicated that the induction of epithelial–mesenchymal transition (EMT) via the TGF-β1/Smad signaling pathway leads to SS metastasis.

Methods

We analyzed the effects of SYT-SSX1 on the stemness of SS cells via TGF-β1/Smad signaling in vitro. The SYT-SSX1 fusion gene high expression cell was constructed by lentiviral stable transfer technology. SYT-SSX1 and SW982 cells were cultured and tested for sphere-forming ability. The transwell migration assay and flow cytometry were used to assess the migration ability of the sphere cells as well as the expression of CSC-related markers. We treated SYT-SSX1 cells with rhTGF-β1 (a recombinant agent of the TGF-β1 signaling pathway) and SB431542 and observed morphological changes. A CCK-8 experiment and a western blot (WB) experiment were conducted to detect the expression of TGF-β1 signaling pathway- and EMT-related proteins after treatment. The SYT-SSX1 cells were then cultured and their ability to form spheres was tested. Flow cytometry, WB, and quantitative real-time polymerase chain reaction (qRT-PCR) were used to detect the expression of CSC surface markers on SYT-SSX1 sphere cells.

Results

It was found that SYT-SSX1 has stronger sphere-forming ability, migration ability, and higher expression of CSC-related molecules than SW982 cells. Through treating SYT-SSX1 and SW982 cells with rhTGF-β1 and SB431542, we found that TGF-β1 enhanced the proliferation of cells, induced EMT, and that TGF-β1 enhanced the characteristics of tumor stem cells.

Conclusions

Our results suggest that SYT-SSX1 enhances invasiveness and maintains stemness in SS cells via TGF-β1/Smad signaling. These findings reveal an effective way to potentially improve the prognosis of patients with SS by eliminating the characteristics of cancer stem cells (CSCs) during treatment.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09229-5.

Clinical Significance and Risk Factors of Local Recurrence in Synovial Sarcoma: A Retrospective Analysis of 171 Cases

Objective: To investigate risk factors of local recurrence of synovial sarcoma and the impact of local recurrence on survival.

Methods: We retrospectively reviewed clinical data of patients with II to IIIB (AJCC8) synovial sarcoma who underwent surgery at our center between March 2005 and December 2016. Data relating clinicopathological factors, treatment and prognosis were collected. The impact of local recurrence on overall survival (OS), local recurrence-free survival (LRFS), and distant relapse-free survival (DRFS) were analyzed. The prognostic factors associated with local recurrence were also analyzed using Kaplan-Meier Curves and Cox regression analysis.

Results: A total of 171 patients were included in this analysis. After a median follow-up of 48 months, 66 patients (38.6%) experienced local recurrence. The 5-year OS, LRFS, and DRFS rates of patients with local recurrence were 37.6, 6.1, and 24.1%, respectively. Multivariate analysis showed that larger initial tumors, multiple recurrences, positive resection margins, marginal resection, and lack of adjuvant therapy were associated with higher local recurrence.

Conclusion: Local recurrence of synovial sarcoma is associated with distant metastasis and poor survival. Chemoradiation improves the prognosis of patients with local recurrence, in particular those for which recurrence occurs shortly after initial treatment.

Clinical Characteristics, Pathology and Outcome of 237 Patients With Synovial Sarcoma: Single Center Experience

BACKGROUND

Synovial sarcoma (SS) is a rare soft tissue sarcoma. Available data regarding survival outcomes of patients with SS still remains limited. In this study, a single center retrospective analysis was performed to investigate the clinical characteristics, pathology and survival outcomes in patients with SS in China.

METHODS

Patient data were systematically reviewed at the National Cancer Center from January 2015 to December 2020. The general information and treatment condition of patients were collected. Overall survival (OS) was evaluated using the Kaplan-Meier and Cox regression method.

RESULTS

A total of 237 consecutive patients were included in this study (follow-up cut-off date: December, 2020). The median age of patients involved was 35 years (ranging from 5 to 83 years) and the mean tumor diameter was 5.3 cm (ranging from .2 to 26.0 cm). The main findings of the immunohistochemical staining analyses were EMA (111/156) (71%), keratin (32/64) (50.0%), keratin (12/20) (60%), keratin (42/70) (60%), S-100 (18/160) (11%), BCL-2 (128/134) (96%), CD99 (137/148) (93%) and TLE1 (23/26) (88%). It was found that 109 patients (66%) were presented with monophasic subtype and 55 (34%) with biphasic subtype. A total of 137 patients were tested by FISH method and 119 patients (87%) demonstrated SS18 rearrangement, whereas 18 patients (13%) did not show SS18 rearrangement. Generally, it was found that the 3-year OS rate was 86% and the 3-year DFS was 55%. Results of univariate analysis revealed that age, tumor size, tumor site, radiotherapy and targeted therapy were significantly correlated with the overall survival (P < .05). Further, multivariate Cox regression analysis revealed that age, tumor size and radiotherapy were significantly associated with OS (P < .05).

CONCLUSIONS

In conclusion, this study shows that the outcomes of patients with SS significantly decrease with age and tumor size. It was evident that radiotherapy is an independent and positive prognostic factor for patients with SS. In addition, it was shown that the prognosis of SS varies with tumor location. For instance, primary tumors in lower extremities have a higher prognosis, whereas tumors located in thorax have a lower prognosis.

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.

Primary gastric synovial sarcoma resected by laparoscopic endoscopic cooperative surgery of the stomach: a case report

Background

Primary gastric synovial sarcoma is extremely rare, only 44 cases have been reported so far, and there have been no reports of laparoscopic endoscopic cooperative surgery for this condition.

Case presentation

A 45-year-old male patient presented with gastric pain. Esophagogastroduodenoscopy was performed that led to the identification of an 8-mm submucosal tumor in the anterior wall of the antrum, and a kit-negative gastrointestinal stromal tumor was suspected following biopsy. On endoscopic ultrasonography, the boundary of the tumor, mainly composed of the second layer, was depicted as a slightly unclear low-echo region, and a pointless no echo region was scattered inside. A boring biopsy revealed synovial sarcoma. Positron emission tomography did not reveal fluorodeoxyglucose (¹⁸F-FDG) accumulation in the stomach or other organs. Thus, the patient was diagnosed with a primary gastric synovial sarcoma, and laparoscopic endoscopic cooperative surgery was performed. The tumor of the antrum could not be confirmed laparoscopically from the serosa, and under intraoperative endoscopy, it had delle on the mucosal surface, which was removed by a method that does not involve releasing the gastric wall. Immunohistochemistry showed that the spindle cells were positive for EMA, BCL-2 protein, TLE-1, and SS18-SSX fusion-specific antibodies but negative for KIT and DOG-1. The final pathological diagnosis was synovial sarcoma of the stomach. The postoperative course was good, and the patient was discharged from the hospital on the 11th postoperative day.

Conclusion

Resection with laparoscopic endoscopic cooperative surgery (LECS), which has not been reported before, was effective for small synovial sarcomas that could not be confirmed laparoscopically. With the combination of laparoscopic and endoscopic approaches to neoplasia with a non-exposure technique (CLEAN-NET) procedure, it was possible to excise the tumor with the minimum excision range of the gastric serosa without opening the stomach.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40792-021-01310-8.

The effect of adjuvant therapies on long-term outcome for primary resected synovial sarcoma in a series of mainly children and adolescents

Background

The benefit of adjuvant therapy in synovial sarcoma (SS) treatment is under debate. Long-term follow-up data are missing.

Methods

SS patients treated in the consecutive trials CWS-81, CWS-86, CWS-91, CWS-96, CWS-2002-P, and the SoTiSaR-registry till 2013 were analyzed.

Results

Median age of 185 patients was 13.9 years (0.1–56)—with median follow-up of 7.4 years for 163 survivors. Most tumors (76%) were located in extremities. Size was < 3 cm in 58 (31%), 3–5 cm in 59 (32%), 5–10 cm in 42 (23%), and > 10 cm in 13 (7%) (13 missing). In 84 (45%) tumors, first excision was complete (R0 corresponding to IRS-I-group) and in 101 (55%) marginal (R1 corresponding to IRS-II-group). In a subsequent surgical intervention during chemotherapy, R0-status was accomplished in 23 additional IRS-II-group patients with secondary surgery. Radiotherapy was administered to 135 (73%), thereof 62 with R0-status and 67 R1-status (6 missing information). Adjuvant chemotherapy was administered to all but six patients. 5-year event-free (EFS) and overall survival (OS) was 82.9% ± 5.7 (95%CI) and 92.5% ± 3.9. Local and metastatic relapse-free survival was 91.3% ± 4.3 and 92.3% ± 4.1 at 5 years, respectively. In the multivariate analysis, tumor size and no chemotherapy were independently associated with EFS. Size and site were associated with OS. In a detailed analysis of local and metastatic events, tumor size was associated with an independent risk for developing metastases. No independent factor for suffering local recurrence could be identified.

Discussion

Omission of chemotherapy in a non-stratified way seems not justified. Size governs survival due to high linear association with risk of suffering metastatic recurrence in a granular classification.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00432-021-03614-6.

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.

Liquid Biopsy Targeting Monocarboxylate Transporter 1 on the Surface Membrane of Tumor-Derived Extracellular Vesicles from Synovial Sarcoma

The lack of noninvasive biomarkers that can be used for tumor monitoring is a major problem for soft-tissue sarcomas. Here we describe a sensitive analytical technique for tumor monitoring by detecting circulating extracellular vesicles (EVs) of patients with synovial sarcoma (SS). The proteomic analysis of purified EVs from SYO-1, HS-SY-II, and YaFuSS identified 199 common proteins. DAVID GO analysis identified monocarboxylate transporter 1 (MCT1) as a surface marker of SS-derived EVs, which was also highly expressed in SS patient-derived EVs compared with healthy individuals. MCT1+CD9+ EVs were also detected from SS-bearing mice and their expression levels were significantly correlated with tumor volume (p = 0.003). Furthermore, serum levels of MCT1+CD9+ EVs reflected tumor burden in SS patients. Immunohistochemistry revealed that MCT1 was positive in 96.7% of SS specimens and its expression on the cytoplasm/plasma membrane was significantly associated with worse overall survival (p = 0.002). Silencing of MCT1 reduced the cellular viability, and migration and invasion capability of SS cells. This work describes a new liquid biopsy technique to sensitively monitor SS using circulating MCT1+CD9+ EVs and indicates the therapeutic potential of MCT1 in SS.

Primary Renal Synovial Sarcoma and Clinical and Pathological Findings: a Systematic Review

PURPOSE OF REVIEW

To update epidemiological, diagnostic, and therapeutic information on primary synovial sarcoma of the kidney.

RECENT FINDINGS

A total of 96 studies were analyzed; age at presentation was 38.6±14.2 years, predominant location of tumor was right kidney; frequent reported symptoms at diagnosis were hematuria and pain. For definitive diagnosis, cytogenetic technique was used. Detected oncogene was available in 37.8% cases with fusion of SS18-SSX in most patients. Surgery is treatment of choice, with adjuvant chemotherapy; most frequently ifosfamide-based associated with doxorubicin or epirubicin. Overall median survival was 34 months. Mortality was 29% of the cases which reported death and the recurrence rate was 39.8%. Risk of death was increased in patients with metastases at diagnosis Primary RSS occurs more often in young men. RSS often presents with symptoms and in an advanced stage. Surgical treatment is the most commonly used and chemotherapy for advanced or recurrent treatment.

Synovialosarcoma of the pharynx: A case report and literatture review

•

Synovial sarcoma is a rare malignant neoplasm.

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The location in pharynx is extremely rare.

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The diagnosis of synovial sarcoma is confirmed by surgical biopsy.

•

The objective of this study is to describe the clinical, radiological and histological features of pharyngeal synovial sarcoma and to discuss its therapeutic management.

Introduction

Synovial sarcoma is a rare tumor to be encountered in the head and neck region and is always a challenge in terms of diagnosis, treatment, as our case.

Presentation of case

We present a 23-year old female patient with synovial sarcoma of posterolateral pharyngeal wall. The radiological and clinicopathological features along with various diagnostic tests and treatment options are discussed.

Discussion

The objective of this study is to describe - from a clinical case reported from our institution, and from literature review- the clinical, radiological and histological features of pharyngeal synovial sarcoma and to discuss its therapeutic management.

Conclusion

Synovial sarcoma of pharynx is extremely a rare tumor in current practice.

The Oncolytic Activity of Myxoma Virus against Soft Tissue Sarcoma Is Mediated by the Overexpression of Ribonucleotide Reductase

BACKGROUND

Myxoma virus (MYXV) is an oncolytic poxvirus that lacks the gene for 1 of the subunits of ribonucleotide reductase (RR), a crucial DNA synthesis and repair enzyme. The overexpression of RR has been implicated in the invasiveness of several cancers, including soft tissue sarcomas (STS). The purpose of the study was to investigate the oncolytic efficacy of MYXV in STS with different levels of RR expression.

METHODS

The oncolytic effect of recombinant MYXV was evaluated in 4 human STS cell lines, LS141 (a dedifferentiated liposarcoma), DDLS8817 (a dedifferentiated liposarcoma), RDD2213 (recurrent dedifferentiated liposarcoma), and HSSYII (a synovial sarcoma) using infectivity and cytotoxicity assays. Following the overexpression of RRM2 by cDNA transfection and silencing of RRM2 by siRRM2 in these STS cell lines, the RRM2 expression levels were analyzed by Western blot.

RESULTS

We observed a direct correlation between viral oncolysis and RRM2 mRNA levels (R = 0.96) in STS. Higher RRM2 expression was associated with a more robust cell kill. Silencing the RRM2 gene led to significantly greater cell survival (80%) compared with the control group (P = .003), whereas overexpression of the RRM2 increased viral oncolysis by 33% (P < .001).

CONCLUSIONS

Our results show that the oncolytic effects of MYXV correlate directly with RR expression levels and are enhanced in STS cell lines with naturally occurring or artificially induced high expression levels of RR. Myxoma virus holds promise in the treatment of advanced soft tissue cancer, especially in tumors overexpressing RR.

Candidate Biomarkers for Specific Intraoperative Near-Infrared Imaging of Soft Tissue Sarcomas: A Systematic Review

Simple Summary

Near-infrared imaging of tumors during surgery facilitates the oncologic surgeon to distinguish malignant from healthy tissue. The technique is based on fluorescent tracers binding to tumor biomarkers on malignant cells. Currently, there are no clinically available fluorescent tracers that specifically target soft tissue sarcomas. This review searched the literature to find candidate biomarkers for soft tissue sarcomas, based on clinically used therapeutic antibodies. The search revealed 7 biomarkers: TEM1, VEGFR-1, EGFR, VEGFR-2, IGF-1R, PDGFRα, and CD40. These biomarkers are abundantly present on soft tissue sarcoma tumor cells and are already being targeted with humanized monoclonal antibodies. The conjugation of these antibodies with a fluorescent dye will yield in specific tracers for image-guided surgery of soft tissue sarcomas to improve the success rates of tumor resections.

Abstract

Surgery is the mainstay of treatment for localized soft tissue sarcomas (STS). The curative treatment highly depends on complete tumor resection, as positive margins are associated with local recurrence (LR) and prognosis. However, determining the tumor margin during surgery is challenging. Real-time tumor-specific imaging can facilitate complete resection by visualizing tumor tissue during surgery. Unfortunately, STS specific tracers are presently not clinically available. In this review, STS-associated cell surface-expressed biomarkers, which are currently already clinically targeted with monoclonal antibodies for therapeutic purposes, are evaluated for their use in near-infrared fluorescence (NIRF) imaging of STS. Clinically targeted biomarkers in STS were extracted from clinical trial registers and a PubMed search was performed. Data on biomarker characteristics, sample size, percentage of biomarker-positive STS samples, pattern of biomarker expression, biomarker internalization features, and previous applications of the biomarker in imaging were extracted. The biomarkers were ranked utilizing a previously described scoring system. Eleven cell surface-expressed biomarkers were identified from which 7 were selected as potential biomarkers for NIRF imaging: TEM1, VEGFR-1, EGFR, VEGFR-2, IGF-1R, PDGFRα, and CD40. Promising biomarkers in common and aggressive STS subtypes are TEM1 for myxofibrosarcoma, TEM1, and PDGFRα for undifferentiated soft tissue sarcoma and EGFR for synovial sarcoma.

Synovial sarcoma of the head & neck: A review of reported cases in the literature

Synovial sarcoma is a high-grade malignancy that seldom manifests in the head and neck. The purpose of this paper is to provide a comprehensive review of the existing literature on primary HNSS. This review study includes case reports, case series and retrospective cohort studies on primary HNSS published in the English language. All cases identified via PubMed were analyzed individually. Articles were included according to specified eligibility criteria. The total number of cases analyzed was 243 (91 case reports, 53 cases from 16 case series, and 99 cases from 8 retrospective cohort studies). The average age at the time of HNSS diagnosis was 33.5 years. The ratio of male-to-female was 1.64:1. The most frequently occurring histologic subtype was biphasic (59.2%). The most common location was the neck. Hoarseness was the most common presenting symptom. Almost all patients (98.3%) underwent surgical excision. 55.6% of patients received adjuvant radiotherapy. A smaller number of patients (30.7%) received adjuvant chemotherapy. 60.3% of patients were alive with no evidence of disease at follow-up while 28.0% of patients died of HNSS at follow-up. The average follow-up period was 52.0 months. Synovial sarcoma is a rare head and neck malignancy. Surgical excision with adjuvant radiation is the most frequently employed treatment modality. Regardless of treatment modality, the prognosis of the tumor is guarded.

The Long-Term Outcomes of Intensive Combined Therapy of Adult Patients with Localised Synovial Sarcoma

Introduction: Synovial sarcoma (SaSy) is a high-grade, malignant soft tissue sarcoma (STS) accounting for 5–9% of STS. The aim of this study was to analyse outcomes of patients with localised SaSy treated in a single institution with a uniform neo- and adjuvant-combined therapy protocol. Methods: 171 patients with stage II/III SaSy were treated between 1997 and 2014. Chemotherapy consisted of 4 cycles of ifosfamide 12 g/m² and two cycles of a doxorubicin-based regimen 75 mg/m². With the exception of patients who underwent amputation, all patients received neoadjuvant radiotherapy. Results: Median age was 33 years (range 17–69). Tumours larger than 5 cm in size were found in 70% of patients. The 5-year overall survival (OS), local relapse-free survival (LRFS) and metastasis-free survival (MFS) rates were 75%, 80% and 60%, respectively. In multivariate Cox’s regression, age > 35 years, male sex, larger tumour size and histology other than monophasic were associated with worse OS. Conclusions: In adult patients with localised SaSy, long-term survival can be achieved in a significant proportion of cases with intensive combined therapy. The multivariate analysis identified age, sex, disease stage and histology subtype as independent prognostic factors of OS.

Systematic literature review of clinical outcomes in adults with metastatic or advanced synovial sarcoma

Background: Synovial sarcoma (SS) is a rare, aggressive soft tissue sarcoma with a poor prognosis after metastasis. The objective of this study was to conduct a systematic review of the clinical evidence for therapeutic options for adults with metastatic or advanced SS. Materials & methods: Relevant databases were searched with predefined keywords. Results: Thirty-nine publications reported clinical data for systemic treatment and other interventions. Data on survival outcomes varied but were generally poor (progression-free survival: 1.0-7.7 months; overall survival: 6.7-29.2 months) for adults with metastatic and advanced SS. A high frequency of neutropenia with systemic treatment and low quality of life post-progression were reported. Conclusion: Reported evidence suggests poor outcomes in adults with metastatic and advanced SS and the need for the development of new treatment modalities.

Radiotherapy is Associated With Improved Survival in Patients With Synovial Sarcoma Undergoing Surgery: A National Cancer Database Analysis

BACKGROUND

Previous studies have demonstrated an association of perioperative radiotherapy (RT) with improved survival in patients with synovial sarcoma (SS) undergoing surgery, but the mechanism for this is unknown. In this study, we sought to further analyze this association using a hospital-based data set where data on chemotherapy administration and surgical margin status are available.

METHODS

Using the National Cancer Database, we identified 1216 patients with SS (aged ≥18 y) from 2004-2012 undergoing surgery. Cox proportional hazards analysis was used to study the effect of clinicopathologic variables on overall survival (OS).

RESULTS

Mean age at diagnosis was 41.5 y (range 18-90), and 71.3% of tumors were high grade; 22.9% underwent surgery alone, 59.6% received RT with surgery, 44.2% received chemotherapy with surgery, and 26.3% received trimodality therapy. Age, sex, grade, Charlson-Deyo score, and RT (hazard ratio, 0.676; 95% confidence interval, 0.519-0.880; P = 0.004) were associated with improved OS, whereas chemotherapy (hazard ratio, 1.20; 95% confidence interval, 0.899-1.60; P = 0.217) and surgical margin status were not. Trimodality therapy with surgery, RT, and chemotherapy was associated with improved OS when compared with therapy with surgery and chemotherapy alone.

CONCLUSIONS

In patients with SS undergoing surgery, we observed a significant improved association of OS with the addition of RT when adjusting for comorbidity score, margin status, and receipt of chemotherapy. These data further support routine implementation of RT in the treatment of patients with SS, including those receiving aggressive multimodality and trimodality care.

Treatment of limb synovial sarcoma with metastasis at presentation

Limb synovial sarcoma (LSS) patients with metastasis at presentation usually have a very poor prognosis. Little is known about survival prediction and risk factors in these patients owing to the condition's rarity. Thus, this study examined the survival and prognostic variables of metastatic LSS.Clinical data for LSS patients with metastasis at presentation from 1975 to 2016 were obtained from the surveillance, epidemiology, and end results database. The Kaplan-Meier method was used to determine the survival curves. Univariate and multivariate Cox regression analysis were conducted to identify the prognostic predictors.The study enrolled 217 patients. Male predominance was observed in the metastatic LSS group. The median age at diagnosis of this population was 40 years. The subtypes were "not otherwise specified" (49.8%), spindle cell (32.7%), biphasic (17.1%), and epithelioid cell (0.5%). The 3-year overall and cancer-specific survival rates of the entire group were 27.2% and 28.3%, respectively. Tumor size <10 cm, surgery, radiotherapy, and chemotherapy were independent predictors of improved overall and cancer-specific survival in the multivariate analyses.Comprehensive treatment for LSS patients with metastasis at diagnosis is necessary and effective and can prolong survival.

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.

Challenges of Clinical Management of Adolescent and Young Adults With Bone and Soft Tissue Sarcoma

Clinical management of adolescents and young adults with bone and soft tissue sarcomas is quite challenging, mainly because of different chemotherapy approaches adopted by pediatric and adult oncologists and tumor-associated factors related to this peculiar age group. Overcoming these barriers is essential for adolescent and young adult patients, whose survival and long-term physical effects are worse than their pediatric counterparts. Nowadays, constant efforts from international collaborations between pediatric and adult oncologists of sarcoma groups have optioned in converging toward a common therapeutic strategy, while improving quality of treatment, as well as research advances dedicated to this at-risk age group of patients with sarcomas.

A Retrospective Case Series of Synovial Sarcoma of the Upper Extremity

Purpose

Previous studies have grouped the treatment of axial and appendicular synovial sarcomas. The purpose of this study was to assess the prognostic variables of upper extremity synovial sarcomas (UESS) and compare the outcomes of those who underwent a nononcologic or inadvertent excision prior to definitive resection to those who underwent an initial oncologic resection.

Methods

We reviewed the records of 23 UESS treated with definitive surgery at our institution between 1990 and 2014. There were 13 women and 10 men with a median age of 30 years (6–60) and median follow-up of 63 months (15–248). Prognostic variables, recurrence-free survival (RFS), and overall survival (OS) were then assessed.

Results

Fifteen patients (65%) had a prior unplanned excision. Five patients required an amputation to obtain local control of disease. There were 3 observed local recurrences and 2 distant metastases at a median of 45 months from presentation. We found no difference in need for amputation, RFS, or OS between those who had undergone a planned excision and those who had an unplanned excision.

Conclusion

While we were unable to find a significant difference in outcomes or amputation rates between those who underwent reexcision of a previously unplanned excision and those who underwent an initial planned resection, the high rate of unplanned excision is troubling and should remind practitioners to consider sarcoma in the differential of all upper extremity masses.

TP53 in bone and soft tissue sarcomas

Genomic and functional study of existing and emerging sarcoma targets, such as fusion proteins, chromosomal aberrations, reduced tumor suppressor activity, and oncogenic drivers, is broadening our understanding of sarcomagenesis. Among these mechanisms, the tumor suppressor p53 (TP53) plays significant roles in the suppression of bone and soft tissue sarcoma progression. Although mutations in TP53 were thought to be relatively low in sarcomas, modern techniques including whole-genome sequencing have recently illuminated unappreciated alterations in TP53 in osteosarcoma. In addition, oncogenic gain-of-function activities of missense mutant p53 (mutp53) have been reported in sarcomas. Moreover, new targeting strategies for TP53 have been discovered: restoration of wild-type p53 (wtp53) activity through inhibition of TP53 negative regulators, reactivation of the wtp53 activity from mutp53, depletion of mutp53, and targeting of vulnerabilities in cells with TP53 deletions or mutations. These discoveries enable development of novel therapeutic strategies for therapy-resistant sarcomas. We have outlined nine bone and soft tissue sarcomas for which TP53 plays a crucial tumor suppressive role. These include osteosarcoma, Ewing sarcoma, chondrosarcoma, rhabdomyosarcoma (RMS), leiomyosarcoma (LMS), synovial sarcoma, liposarcoma (LPS), angiosarcoma, and undifferentiated pleomorphic sarcoma (UPS).

Metastatic Synovial Sarcoma: Experience from a Tertiary Care Center from India

Background: Synovial sarcoma represents 8% of all soft-tissue sarcoma (STS). It is a high-grade STS, and 50% of patients develop metastasis. The most common site of metastasis is the lungs, lymph nodes followed by bones. Ifosfamide-based chemotherapy is associated with improved outcome. In this study, we report our experience of metastatic synovial sarcoma according to primary sites, metastatic pattern, and their outcome. Materials and Methods: This was a retrospective observational study carried out at our institute from January 2013 to December 2016. The aim of our study was to evaluate the pattern of metastasis, response to chemotherapy, and survival in patients with metastatic synovial sarcoma. Results: Over a period of 4 years, 43 patients with metastatic synovial sarcoma were diagnosed with median age of 30 years. Nearly 70% of patients had lung metastasis, other site of metastasis were lymph node, bone, and liver. Thirty patients received chemotherapy with a combination of ifosfamide and doxorubicin. The overall response rate was 87% with median progression-free survival of 8 months. Patients with lung only metastasis had better survival compared with nonpulmonary metastatic site (18 months vs. 12 months). The median survival was 18 months. Conclusion: Metastatic synovial sarcoma is chemoresponsive tumor with lung being the most common metastatic site. Patients with lung only metastasis had a better outcome than nonpulmonary metastasis.

Leiomyosarcoma: Prognostic outline of a rare head and neck malignancy

Soft tissue sarcomas (STS) are mesenchymal malignant neoplasms with a broad spectrum of biologic behaviour. Most STS show predilection for extremities with rarity in head and neck. Leiomyosarcoma (LMS) is an extremely rare STS in head and neck due to the paucity of smooth muscles in this anatomical region. Owing to its rarity, diagnosis of LMS is often delayed or is often misdiagnosed. Our study aimed to evaluate clinico-demographic factors determining clinical course of primary head-neck LMS. Further, we also assessed cases of secondary head-neck LMS and LMS due to other causes to compare their clinical outcome with primary head-neck LMS. In primary LMS cases, intraoral LMS showed slightly better prognosis than extraoral LMS. Survival analysis revealed that prognosis of primary LMS was significantly better than secondary LMS. No significant difference in survival was seen between primary LMS and LMS due to other causes. These observations indicate that site of origin appears to determine the clinical behaviour of LMS. Results showed that size, recurrence and metastasis are important prognostic variables. Though large tumor size was associated with poor prognosis, tumor aggressiveness may not be directly proportional to its size. Surgical management with or without adjuvant therapy was associated with favourable outcome. As several factors are associated with prognostic outcome of head-neck LMS, multimodality therapy approach after careful analysis of various prognostic variables in each case on an individual basis is essential.

Favorable outcomes of localized synovial sarcoma patients with a high utilization rate of neoadjuvant and/or adjuvant chemotherapy

Synovial sarcoma (SS) is considered to be a chemosensitive, soft tissue sarcoma. Therefore, neoadjuvant and/or adjuvant chemotherapy (N/AC) is used for the treatment of high-risk SS patients. However, the role of N/AC remains controversial. The present study aimed to review the clinical outcomes of surgically treated localized SS and investigate the effects of N/AC with long-term observation. The clinical outcomes of 54 patients with surgically treated localized SS were retrospectively analyzed. The median patient age was 42 years (range, 8-81 years), and the median follow-up period was 94 months for survivors (range, 7-220 months). A total of 38 patients (70%) received chemotherapy. Of these, 32 (59%) patients received neoadjuvant chemotherapy, 33 (61%) received adjuvant chemotherapy, and 27 (50%) received neoadjuvant and adjuvant chemotherapy. Fourteen patients (26%) received adjuvant radiotherapy. Three patients (6%) had local recurrence and 13 patients (24%) developed distant metastasis. The overall survival (OS) rates at 5 and 10 years were 87 and 84%, respectively. N/AC did not improve survival. In conclusion, we found satisfactory long-term OS among patients with a high utilization rate of N/AC. Further study should be necessary to evaluate which population of SS would benefit from N/AC.

Standard treatment and emerging drugs for managing synovial sarcoma: adult's and pediatric oncologist perspective

INTRODUCTION

in this review we discuss the standard of care for both pediatric and adult synovial sarcoma (SS), the prognostic differences between them, and the treatments available for localized and advanced diseases. We also overview the biology and the recent drugs under consideration in clinical trials on SS. Areas covered: we focus on new targeted therapies being investigated for advanced SS, especially anti-angiogenic drugs, and immunotherapy. We review all the published data and ongoing trials dedicated to SS or to soft tissue sarcoma in general, paying particular attention to the results obtained in SS patients. Expert opinion: we expect new treatment strategies to become available for SS in the near future. The ongoing and published trials on targeted therapies and immunotherapy mainly concern adult patients, but the somatic biology of pediatric SS has some similarities as in adult disease. A stronger cooperation between adult and pediatric oncologists in recent years has led to a more shared effort to find new treatment strategies for advanced SS patients, regardless of their age.

An unusual local invasion of synovial sarcoma

Synovial sarcoma is a malignant tumor, it accounts for approximately 5-10% of the soft tissue sarcoma, and mainly develops in the para-articular regions in adolescents and young adults. We reported a case of synovial sarcoma extending into the vastus intermedius muscle beyond the intermuscular septum which is considered to be the greatest barrier to ensuring a safety margin in musculoskeletal surgery. Preoperative sequential MRI showed the intermuscular-septum line and direct tumoral invasion beyond the intermuscular septum. A histopathological examination showed the direct invasion to the intermuscular septum. Synovial sarcoma seldom shows such direct invasive pattern to barriers, much less the robust barrier like an intermuscular septum. To our knowledge, no previous study has reported such unique extension of a synovial sarcoma beyond the intermuscular septum. Surgeons should be aware of the potential vulnerability of the intermuscular septum.

Surgical excision and not chemotherapy is the most powerful modality in treating synovial sarcoma: the UK's North East experience

BACKGROUND AND PURPOSE

We reviewed our experience of synovial sarcoma to identify factors predictive of local recurrence and overall survival, the impact of chemotherapy and outcomes after surgical excision alone.

MATERIALS AND METHODS

81 patients were treated between 1997 and 2014 of mean age 39 years (8-78). Tumours were in the extremity in 55 (67%). 9 patients presented with metastases and 10 with unresectable disease. Mean follow-up was 3.7 years (SD 3.8). Treatment groups were palliative, surgery only, surgery and radiotherapy, or surgery with chemotherapy (with or without radiotherapy).

RESULTS

Local recurrence-free survival (LRFS) was 73% at 5 years, and 68% at 10 and 15 years. In multivariate analysis, positive surgical margins were an independent predictor of LRFS. Overall survival (OS) was 50% at 5 years for all patients, and 62% at 5 years for those treated with curative intent. Larger tumour size and non-extremity locations were predictors of poorer OS. Patients who had chemotherapy did not have significantly better OS or LRS than others.

INTERPRETATION

These results show that where feasible, curative resection should not be delayed for chemotherapy. Treatment with surgery only can be associated with good outcomes in selected patients with smaller extremity tumours; although our series is small.

Localized synovial sarcoma: A single institutional study of 191 patients with a minimum follow-up of 5 years for survivors

PURPOSE

Factors affecting long-term outcomes of synovial sarcoma (SS) remain unknown. Here, we aimed to investigate the long-term oncological outcomes and prognostic factors in a large group of patients with surgically-treated localized SS.

PATIENTS AND METHODS

Between 1980 and 2011, 191 patients (94 males and 97 females) were treated at a single hospital with a minimum follow-up of 5 years for survivors. The median age was 35 years (range, 3-80 years), and the median follow-up period was 83 months (range, 3-235 months).

RESULTS

Disease-specific survival was 76.4% and 60.4% at 5 and 10 years, respectively. Local recurrence occurred in 23 patients at a median of 33 months (range, 6-158 months), and metastasis occurred in 73 patients at a median of 20 months (range, 2-166 months). In multivariate analysis, grade 3 tumors sized ≥5 cm were significantly associated with worse survival. Ten patients (5.2%) developed metastasis more than 5 years after surgery.

CONCLUSION

Tumor size and grade govern prognosis in surgically-treated localized SS in long-term settings. If adequately treated patients have not developed metastases for 5 years after surgery, the risk of subsequently developing metastases was lower than previously reported.

Genetic and molecular reappraisal of spindle cell adamantinoma of bone reveals a small subset of misclassified intraosseous synovial sarcoma

Adamantinoma represents a distinct group of bone tumors showing both mesenchymal and epithelial differentiation most commonly involving the tibial diaphysis. Most adamantinomas contain a fibro-osseous component and an epithelial component consisting of squamous or basaloid cells. Adamantinomas are considered malignant neoplasms requiring en bloc excision that frequently recur locally and can rarely metastasize. Rare adamantinomas show an epithelial component consisting predominantly of monomorphic spindle cells, which, combined with an epithelial immunophenotype, can mimic monophasic synovial sarcoma. Synovial sarcoma is very rare in bone. It is considered a high-grade sarcoma that typically necessitates chemotherapy. However, the relationship between spindle cell adamantinoma and intraosseous synovial sarcoma has not been investigated. The current study was prompted by identification of a presumed spindle cell adamantinoma of the tibia with diffuse keratin expression that harbored a SS18 gene region rearrangement. FISH of eight additional bone tumors initially classified as spindle cell adamantinoma based on clinicoradiopathologic findings revealed one additional case with SS18 rearrangement. Histologically, both intraosseous synovial sarcoma and spindle cell adamantinoma demonstrated uniform fusiform nuclei with scant cytoplasm, short fascicles and low mitotic activity. The adamantinomas, but not the synovial sarcomas, were more likely to show overt epithelial differentiation in the form of pseudoglands or squamous nests. Immunohistochemistry of all cases, irrespective of SS18 status, showed diffuse keratin positivity in the spindle cell component, and less consistent EMA positivity. Clinical follow-up was available in both intraosseous synovial sarcomas, one of which recurred and the other metastasized. Two of the six spindle cell adamantinomas with follow-up metastasized. The above findings highlight the morphologic and immunophenotypic overlap between spindle cell adamantinoma and intraosseous synovial sarcoma of the tibia. Investigation of SS18 status to exclude synovial sarcoma is suggested prior to rendering a diagnosis of spindle cell adamantinoma.

Proteomic signatures corresponding to the SS18/SSX fusion gene in synovial sarcoma

Synovial sarcoma (SS) is a malignant soft tissue lesion and most commonly arises in young adults. Chromosomal translocation t(X;18)(p11;q11) results in the formation of SS18/SSX by gene fusion of the SS18 gene on chromosome 18 to either SSX1, SSX2, or SSX4 gene located on chromosome X, which is detected in more than 95% of SSs. Although multiple lines of evidence suggest that the SS18/SSX fusion is the oncogene in this tumor, the protein expression profiles associated with SS18/SSX have yet to be elucidated. In this study, we conducted proteomic studies using SS18/SSX knockdown in three SS cell lines to identify the regulated proteins associated with SS18/SSX in SS. Isobaric tags for relative and absolute quantitation (i-TRAQ) analyses identified approximate 1700–2,000 proteins regulated by the SS18/SSX fusion in each SS cell line. We also analyzed the three profiles to identify proteins that were similarly altered in all 3 cell lines and found 17 consistently upregulated and 18 consistently downregulated proteins, including TAGLN and ACTN4. In addition, network analyses identified several critical pathways including RUNX2 and SMARCA4. RUNX2 and SMARCA4 had the highest ranking in these identified pathways. In addition, we found that expression of TAGLN inhibited cell viability in SS cell lines. Our data suggest that the differentiation and cell growth of SS may be enhanced by the identified proteins induced by SS18/SSX. We believe that the findings obtained in the present functional analyses will help to improve our understanding of the relationship between SS18/SSX and malignant behavior in SS.

Clinicopathological features, treatment and survival outcomes of synovial sarcoma

Introduction:

Synovial sarcoma (SS) is a malignant mesenchymal tumor. It is most common among children and adults. The data on SS from India are scarce. In this study, we analyzed the clinicopathological treatment parameters and survival outcomes of SS patients.

Materials and Methods:

A total of 57 histologically proven SS diagnosed from 2010 to 2016 were retrospectively analyzed.

Results:

The median age was 23 years with a male-to-female ratio of 1.28:1. Localized disease was seen in 44 patients (77%) and 13 patients (23%) had metastasis. The primary sites of involvement such as lower limb, upper limb, thorax, and abdomen were seen in 60%, 28%, 7%, and 5% patients, respectively. Surgery was done in 39 patients and 18 patients had unresectable disease. Adjuvant chemotherapy with doxorubicin-based regimen was given in 30 patients and adjuvant radiotherapy in 21 patients. Palliative chemotherapy with anthracycline-based or gemcitabine-based regimen was used in 17 and 2 patients, respectively. The median event-free survival (EFS) was 30 months with 3 years and EFS rate was 36%; median progression-free survival (PFS) was 11.5 months and 1 year; and PFS rate was 38%. On univariate analysis, resection and performance status were significantly associated with survival. There is no impact of grade and size of the tumor on survival. In metastatic patients, the lung is the most common site.

Conclusion:

SS is the most common soft-tissue sarcoma among adults. Resectability and performance status were impacting the survival.

In silico and in vitro screening of small molecule Inhibitors against SYT-SSX1 fusion protein in synovial sarcoma

Synovial sarcoma (SS) is characterized by a tumour specific chromosomal translocation t(X;18) (p11;q11) which results in the formation of SYT-SSX1 fusion protein. This fusion protein represents a clear therapeutic target and molecules specifically targeting SYT-SSX1 fusion protein are currently not available. In this study, SYT-SSX1 fusion protein sequence was retrieved from Uniprot and 3D structure was generated using I-TASSER modeling program. A structure based computational screening approach has been employed using Glide docking software to identify potential SYT-SSX1 small molecule inhibitors that bind to the junction region of the fusion protein. The obtained inhibitors were further filtered based on the docking score and ADME/T properties. Ten best fit compounds were chosen for in vitro studies. The anti-proliferative activities of these 10 compounds were screened in Yamato, ASKA (carries SYT-SSX1 fusion protein) and other sarcoma cell lines such as A673, 143B to understand the specificity of inhibition of the chosen compounds. The in vitro activity was compared against HEK293 cell lines. The compound 5-fluoro-3-(1-phenyl-1H-tetraazol-5-yl)-1H-indole (FPTI) was found to be selectively cytotoxic in synovial sarcoma cell lines (Yamato and ASKA) and this compound also showed insignificant anti proliferative activity on other cell lines. Further, target gene expression study confirmed that FPTI treatment down-regulated SYT-SSX1 and modulated its downstream target genes. Cell cycle analysis revealed the involvement of an apoptotic mechanism of cell death. Further experimental validations may elucidate the therapeutic potentials of FPTI against SYT-SSX1 fusion protein.

Prognostic impact of the tumor immune microenvironment in synovial sarcoma

The association between the immune status within the tumor microenvironment and prognosis in synovial sarcoma is not well understood. We aimed to investigate the tumor immune microenvironment and analyze its prognostic impact for patients with synovial sarcoma. A total of 36 primary patients who were treated in our institution were retrospectively evaluated. Infiltration of lymphocytes (CD4+, CD8+, and FOXP3+), CD163+ macrophages, and expression of human leukocyte antigen (HLA) class I and programmed death ligand 1 (PD-L1) were evaluated by immunohistochemistry. Moreover, we investigated PD-L1 and programmed death ligand 2 (PD-L2) mRNA expression in 19 of the 36 cases, using real-time PCR. The Kaplan-Meier method was used to estimate overall survival and progression-free survival. Infiltration of lymphocytes and macrophages varied among the patients. Furthermore, the expression of HLA class I was negative or downregulated in 11 specimens. No PD-L1 expression was observed using immunohistochemistry. Moreover, although PD-L1 mRNA expression was observed in 18 of 19 specimens, the expression level was low. A higher infiltration of CD8+ or FOXP3+ lymphocytes in patients was associated with a favorable overall survival. In addition, a higher infiltration of CD163+ macrophages indicated a significantly worse overall and progression-free survival. Infiltration of CD4+ lymphocytes, HLA class I, PD-L1, and PD-L2 expression were not associated with patient prognosis. This represents the first report investigating the tumor immune microenvironment as a prognostic factor in synovial sarcoma, indicating that CD163+ macrophages are associated with tumor progression. Our results underscore the clinical significance of the tumor immune microenvironment in synovial sarcoma.

Synovial sarcoma: Do children do better?

OBJECTIVES

Synovial sarcoma, a distinct subtype of soft tissue sarcomas (STS), is typically found in young patients. Long history of symptoms and heterogeneous clinical presentation sometimes delays diagnosis. Children have been reported to have a better prognosis than adults in some series. The main emphasis of this study was to determine differences between children and adults and to investigate prognostic factors regarding cancer specific survival (CSS).

METHODS

248 patients treated between 1982 and 2014 at one department were included. Mean age was 37.0 years, including 43 patients <16 years. Demographic, pathology- and treatment-related information was ascertained. Median follow-up was 5.2 years.

RESULTS

Median duration of symptoms was 11.5 months in children and 12 months in adults (p = 0.238). Patients with a prior unplanned excision had a significantly longer duration of symptoms (p = 0.001). No difference was present between children and adults regarding tumour size, site, grade and superficial/deep location. Treatment was with surgical excision and (usually) adjuvant radiotherapy but five patients received preoperative radiotherapy and 43 patients chemotherapy. In patients treated with curative intent, five-year CSS rates were 75.5% for adults and 89.0% for children, with 10-year CSS rates of 56.1% and 82.2% (p = 0.026). In multivariate analysis, large tumour size (p < 0.005) and patient age (p = 0.024) were associated with worse CSS, irrespective of tumour location and site.

CONCLUSION

Clinical presentation of synovial sarcoma is similar in children and adults, with no significant difference in tumour size, site, grade or location. Small tumour size and young patient age are independent positive prognostic factors influencing CSS.

The challenge of the management of adolescents and young adults with soft tissue sarcomas

Soft tissue sarcomas are relatively frequent in adolescents and young adults and their clinical management may be complex, partly due to tumor associated factors, but also because different approaches have been adopted by pediatric and adult medical oncologists dealing with the same disease. However, times are changing and in the last few years, management has tended to converge towards a common strategy. Continued and increased international collaboration between pediatric and adult sarcoma groups is of critical importance to improve the quality of treatment as well as research programs dedicated to young patients with soft tissue sarcomas.

α-particle therapy for synovial sarcoma in the mouse using an astatine-211-labeled antibody against frizzled homolog 10

Synovial sarcoma (SS) is a rare yet refractory soft‐tissue sarcoma that predominantly affects young adults. We show in a mouse model that radioimmunotherapy (RIT) with an α‐particle emitting anti‐Frizzled homolog 10 (FZD10) antibody, synthesized using the α‐emitter radionuclide astatine‐211 (²¹¹At‐OTSA101), suppresses the growth of SS xenografts more efficiently than the corresponding β‐particle emitting anti‐FZD10 antibody conjugated with the β‐emitter yettrium‐90 (⁹⁰Y‐OTSA101). In biodistribution analysis, ²¹¹At was increased in the SS xenografts but decreased in other tissues up to 1 day after injection as time proceeded, albeit with a relatively higher uptake in the stomach. Single ²¹¹At‐OTSA101 doses of 25 and 50 μCi significantly suppressed SS tumor growth in vivo, whereas a 50‐μCi dose of ⁹⁰Y‐OTSA101 was needed to achieve this. Importantly, 50 μCi of ²¹¹At‐OTSA101 suppressed tumor growth immediately after injection, whereas this effect required several days in the case of ⁹⁰Y‐OTSA101. Both radiolabeled antibodies at the 50‐μCi dosage level significantly prolonged survival. Histopathologically, severe cellular damage accompanied by massive cell death was evident in the SS xenografts at even 1 day after the ²¹¹At‐OTSA101 injection, but these effects were relatively milder with ⁹⁰Y‐OTSA101 at the same timepoint, even though the absorbed doses were comparable (3.3 and 3.0 Gy, respectively). We conclude that α‐particle RIT with ²¹¹At‐OTSA101 is a potential new therapeutic option for SS.