Synovial Sarcoma

P2, N=87, Active, not recruiting, Adaptimmune

Exposure to GSK343 or ATRA results in inhibition of cell proliferation and induction of cellular senescence, where GSK343 shows a dominant effect. The Figure was created with Biorender.com.

While TRPS1 remains a highly sensible immunohistochemical marker for confirming breast primary lesions, pathologists should be aware of its low specificity and incorporate complementary diagnostic methods in order to ensure accurate clinical management. Further research should focus on elucidating the molecular pathways regulating TRPS1 expression in various tumor types, which may better define its clinical utility.

Treatment of synovial sarcoma typically comprises local surgery, radiotherapy and chemotherapy, while novel managements such as immunotherapy, targeted therapies and epigenetic modifiers are explored. This review focuses on the recent studies of SS18-SSX fusion gene, epigenetic landscape, signaling pathways, diagnostic techniques, and relevant therapeutic advances, aiming to inhibit the oncogenic processes and improve outcomes for patients with synovial sarcoma.

Furthermore, FANCI overexpression partially reversed the effects of SSX2IP knockdown on cell proliferation and metastasis. In summary, our findings revealed that SSX2IP contributes to the progression of breast cancer by regulating FANCI, hinting at its potential as a novel biomarker and therapeutic target for the treatment of breast cancer.

Our findings indicated that tyrosine kinase receptors are upregulated in NRSTS and exhibited a distinct expression pattern within various subgroups. High expression of VEGFR2 and PDGFRα significantly correlated with reduced survival and may guide targeted therapy approaches for this poor prognosis group of patients.

Consequently, this leads to the downregulation of tumor suppressor genes occupied by SS18 physiologically, like CAV1 and DAB2. These results reveal the underlying mechanism of genomic disorder and tumorigenesis caused by the remodeling of oncoprotein SS18-SSX1 condensates at the macroscopic level.

Novel approaches to treating synovial sarcoma include immune-based therapies (such as TCR-T cell therapy to NY-ESO-1, MAGE4, PRAME or using immune checkpoint inhibitors), epigenetic modifiers (HDAC inhibitors, EZH2 inhibitors, BRD disruptors), as well as novel or repurposed receptor tyrosine kinase inhibitors. In the presented review, we aimed to summarize the genetic and epigenetic landscape of SS as well as to find out the potential niches for the development of novel diagnostics and therapies.

SS18-SSX-positive staining may be used as a surrogate for FISH assay in a resource-limited setting where molecular assay is not available. Furthermore, IHC has a fairly shorter turn-around-time, is less complex, and of low cost.

P2, N=7, Active, not recruiting, Adaptimmune | Trial completion date: Jul 2024 --> Jul 2025

We identified three unique sarcoma cell cycle phenotypes that have prognostic significance. This performs similarly to the AJCC staging system.

In August 2024, afamitresgene autoleucel was approved in the USA under accelerated approval for the treatment of adults with unresectable or metastatic synovial sarcoma who have received prior chemotherapy, are HLA-A*02:01P, -A*02:02P, -A*02:03P or -A*02:06P positive and whose tumour expresses the MAGE-A4 antigen as determined by FDA-approved or cleared companion diagnostic devices. This article summarizes the milestones in the development of afamitresgene autoleucel leading to this first approval for the treatment of advanced synovial sarcoma.

Our study identifies SUMO2 as a selective dependency in synovial sarcoma. We demonstrate that the SUMO2/3 inhibitor TAK-981 impairs sarcomagenesis and reverses the SS18-SSX fusion-driven oncotranscriptome. Our study indicates that SUMO2 inhibition may be an attractive therapeutic option in synovial sarcoma.

P1, N=22, Active, not recruiting, University Health Network, Toronto | Trial completion date: Sep 2024 --> Sep 2025 | Trial primary completion date: Sep 2024 --> Sep 2025

DUX4 IHC is a highly sensitive and specific surrogate marker for the presence of CIC::DUX4 fusion, demonstrating its utility in establishing a diagnosis of CRS.

P1/2, N=27, Not yet recruiting, University of Florida

P=N/A, N=0, Available, Adaptimmune

POU2F3 expression is a highly sensitive but nonspecific indicator of tuft cell differentiation. Co-expression of POU2F3 and POU2AF2 appears to be a more specific marker, although it may not pinpoint tumors driven by the POU2F3-POU2AF3 complex.

The transcription factor FOXP1 was found to interact with BRD9 to regulate CST1 expression. Collectively, these results suggest that BRD9 may be a promising biomarker and therapeutic target for GBC.

P1, N=92, Recruiting, City of Hope Medical Center | Active, not recruiting --> Recruiting | Trial completion date: Sep 2024 --> Jan 2026 | Trial primary completion date: Sep 2024 --> Jan 2026

An exact confirmation by molecular testing has treatment-associated implications. A review of similar reported cases is presented herewith.

Atypical SS18-break apart FISH pattern with loss of green signal should be interpreted as a peculiar unbalanced rearrangement of the SS18 gene and subsequent SS18-SSX fusion (IHC or/and NGS) test should be recommended in such cases. Reseach are partially supported by grant of the The National Centre for Research and Development no. GOSPOSTRATEG-VI/0016/2021.

Our cases on atypical presentations of SS shows unusual morphological, immunophenotype, and molecular features. We consider it relevant to include SS as a differential diagnosis when faced with pseudo-vascular/alveolar patterns. Even in cases with more typical morphology of SS, there is a possibility of finding negative results in either IHC or FISH techniques due to cryptic or complex rearrangement.

KRT8 was identified as a key component for epithelial differentiation in biphasic tumors, potentially controlled by OVOL1 regulation. Our findings explain the histological grounds for SS classification and indicate that a significantly larger proportion of patients have high risk tumors (corresponding to SS subtype I) than previously believed.

We found that MTLN overexpression or knockout respectively decreased or increased expression of the inflammation-associated genes, including IL-6, IL-8, and TNF-α. Thus, high levels of MTLN in osteoarthritis may protect tissues against excessive inflammation, thereby offering therapeutic potentials.

Among MAGE-As, MAGE-A4 had the highest prevalence (65%), followed by MAGE-A10 (15%) and MAGE-A9 (13%)...Complementary immunohistochemical analyses were used to establish the positive correlation between RNA and protein expression for MAGE-A4 and NY-ESO-1. These data inform the strategy for optimal coverage of the SyS patient population with T-cell therapies, offering patients with SyS new options for single or combined second lines of treatment.

Such entities may benefit from alternative treatments or strategies to overcome SLFN11 deficiency-related drug resistance. Our approach and results should serve as a foundation for future biomarker-associated clinical trials.

Additionally, we confirmed that this cell line was useful for evaluating the efficacy of anticancer drugs. Our results suggest that NCC-SS6-C1 is a useful tool for basic and pre-clinical studies of SS.

The primary tumor cohort showed no association between NY-ESO-1 expression and OS (including stratification by HLA-A∗02 subtype and treatment line), when adjusting for important prognostic factors, possibly due to small sample sizes.

NGS results revealed NRAS and CDKN2A mutations and absence of fusions, resulting in a new review of the histologic material with a broader immunohistochemical panel, finding strong positivity to melanic antibodies. This case is an illustrative example of a malignant melanoma with small round cell morphology showing aberrant expression of CD99, BCL2, TLE1 and SS18-SSX antibodies exposing a potentially hazardous pitfall highlighting the importance of a wide differential diagnosis and the role of confirmational studies with molecular tests.

Oral administration effectively inhibited HS-SY-II xenograft tumor growth in mice. CW-3308 is a promising lead compound for further optimization and extensive evaluation for the treatment of synovial sarcoma, rhabdoid tumor, and other BRD9-dependent human diseases.

"Thermo Fisher Scientific Inc...announced that its SeCore CDx HLA A Sequencing System has been granted 510(k) clearance by the United States Food and Drug Administration (FDA) for use as a companion diagnostic with TECELRA (afamitresgene autoleucel), Adaptimmune’s newly approved T-cell receptor (TCR) therapy for the treatment of adults with unresectable or metastatic synovial sarcoma who have received prior chemotherapy, are HLA-A*02:01P, -A*02:02P, -A*02:03P, or -A*02:06P positive and whose tumor expresses the MAGE-A4 antigen as determined by FDA-approved or cleared companion diagnostic devices. Synovial sarcoma is a rare, soft tissue cancer that most commonly impacts young adults."

"Agilent Technologies Inc...announced that it has received FDA approval for the use of MAGE-A4 IHC 1F9 pharmDx (SK032) as a diagnostic tool to aid in identifying patients with synovial sarcoma who may be eligible for treatment with TECELRA (afamitresgene autoleucel, also known as afami-cel or ADP-A2M4), a MAGE-A4-directed engineered TCR T-Cell therapy."

Moreover, these markers could represent therapeutic targets in advanced stages. However, further, larger series of SSs and molecular studies are necessary to corroborate our present findings.

Synovial histiocytic sarcomas and myxosarcomas can cause lysis in multiple bones surrounding the joint, but they have different prognoses and require histopathology and sometimes immunohistochemistry to diagnose them. Synovial sarcoma and synovial cell sarcoma are terms used in the human medical literature for a tumor that is not of synovial origin; these terms should not be used in veterinary medicine.

Furthermore, EXO1, NCAPG, POLQ and UHRF1 were identified as potential candidate metastasis-associated genes. This study provides further research insights and helps explore the mechanisms of SS metastasis.

In support of this notion, we find that blockade of FYN activity synergistically enhances HDACi action to reduce synovial sarcoma cell proliferation and migration. Our results support a role for FYN in attenuation of anti-cancer activity upon inhibition of SS18-SSX function and demonstrate the feasibility of targeting FYN to improve the effectiveness of HDACi treatment against synovial sarcoma.

A high fraction of young patients with soft tissue sarcoma harbor PVs. Among the genes affected, we substantiate a potential role of MYO5B and propose a potential role for MYO3A.

This study is a comprehensive study providing real-world data on the expression of several actionable proteins in a large proportion of SynSa samples. All evaluated markers were expressed in a clinically meaningful proportion of cases represented in our TMA, supporting the relevance of ongoing preclinical and clinical research with novel agents directed against these targets.

Taken together, the data shows that (1) lurbinectedin combined with ipilimumab and nivolumab is a safe regimen with a MTD of 3.2 mg/m2 for lurbinectedin and (2) there were no serious treatment related adverse events reported. The phase II part of the study is currently open for previously untreated patient enrollment.

In summary, among the soft tissue tumors tested, ISL1 is a highly sensitive but moderately specific marker for DSRCT and may be useful to distinguish from round cell mimics including EWS and CIC::DUX4 sarcomas. The oncogenic role of ISL1 in these tumors warrants further investigation.

This is the first reported case of synovial sarcoma of the hypopharynx in the Philippines confirmed by SS18 FISH. Due to the size of the mass, chemoradiotherapy followed by surgery is the current plan of management for this patient.