Spindle Cell Sarcoma Research Articles

BCOR-ITD Rearranged Sarcoma in the Mandible of a 5-Year-Old Child: A Case Report Highlighting Diagnostic Distinction From Odontogenic Fibromyxoma.

The 5th edition of the World Health Organization (WHO) classification of soft tissue and bone has recognized three distinct groups among Ewing-like sarcomas, namely, CIC-rearranged sarcoma, sarcomas with BCOR genetic alterations, and round cell sarcomas with EWSR1:: non-ETS fusions. Sarcomas with BCOR genetic alterations are a distinct clinicopathological group of high-grade tumors, representing 5% of small round cell tumors. BCOR-ITD rearranged tumors commonly manifest as spindle cell sarcomas and many of them display low cellularity with monomorphous cell morphology and myxoid background resembling benign fibroblastic tumors. We present an intriguing case report of a 5-year-old boy diagnosed with a moderately cellular mandibular spindle cell tumor exhibiting BCOR-ITD rearrangement which was initially misdiagnosed as an odontogenic fibromyxoma. This case report illustrates the histological and immunophenotypic findings of BCOR-ITD rearranged sarcoma, requiring a comprehensive immunohistochemical panel and additional molecular tests for accurate diagnosis.

The efficacy and safety of anlotinib combined with chemotherapy in treatment of advanced soft tissue sarcoma

BackgroundTo evaluate the efficacy and safety of anlotinib combined with chemotherapy in the treatment of advanced soft tissue sarcoma (STS).MethodsA total of 14 patients with advanced STS consisting of 4 liposarcoma, 3 undifferentiated polymorphous sarcoma, 2 synovial sarcoma, 1 Extraosseous ewing sarcoma, 1 spindle cell sarcoma, 1 Sarcomatoid malignant mesothelioma, 1 hemangiosarcoma, and 1 fibrosarcoma, were treated with anlotinib plus chemotherapy. The anlotinib was combined with chemotherapy as the first-line treatment in 13 patients, and as second-line treatment in 1 patient. Chemotherapy regimens were based on anthracyclines and ifosfamide, and other drugs included paclitaxel, and so on. Efficacy and safety were evaluated every 2 treatment cycles.ResultsAccording to the stage of AJCC, 9 patients were stage III and 5 patients were stage IV. The average cycle of treatment is 3.86. Among the 14 patients, 2 cases had received surgical treatment after neoadjuvant chemothrapy, 5 cases had partial response (PR), 7 cases had stable disease (SD), and 2 cases had progressive disease (PD). The overall response rate (ORR) was 35.7% (5/14). Patients who had not underwent surgical treatment were with a disease control rate (DCR) of 83.3% (10/12). The median progression free survival (PFS) was 8.25 months. The common treatment-related adverse effects included bone marrow suppression, nausea, vomiting and hypertension. Three patients had severe adverse effect, which was febrile neutropenia. No treatment-related death was found.ConclusionsAnlotinib combined with chemotherapy in the treatment of STS is effective and tolerable, which is a promising strategy. It is worthy of further clinical research.

SS18-SSX Expression and Clinicopathologic Profiles in a Contemporary Cohort of Primary Paratesticular Synovial Sarcoma: A Series of Fourteen Patients.

Synovial sarcoma (SS) is a rare genitourinary malignancy with a specific SS18::SSX 1/2 gene fusion in majority of the instances. The paratesticular location of this neoplasm is extremely rare and only 4 cases are reported in the literature. Herein, we describe the clinicopathologic features and molecular profile of paratesticular SS in the largest case series to date and to the best of our knowledge, and the only series to use novel SS18-SSX antibody for immunohistochemistry. Clinicopathologic, immunohistochemical (IHC), molecular, treatment, and follow-up data of the patients were analyzed. There were 14 patients, ranging from 15 to 47 years (mean: 30y). The tumor size ranged from 4​​​​​​ to 15cm. The tumors were unilateral, solid, and homogeneous tan-white with monomorphic spindle cell histology. All 14 tumors expressed SS18-SSX and TLE1 IHC and harbored SS18 rearrangement. In addition, the tumor with multifocal SS18-SSX expression had lower break-apart signals in the FISH assay (38% of the tumor cells; range: 29% to 85%). Radical orchiectomy was performed in all 14 patients and adjuvant chemotherapy was administered in 9 patients. Follow-up was available in 9 patients. The follow-up duration ranged from 5 to 24 months (median=10mo). Four patients died of metastatic disease (range: 5 to 16mo) and 2 patients who are alive had metastatic disease at the last follow-up. Based on our experience with the largest series to date and aggregate of the published data, paratesticular SS has a poor prognosis despite aggressive therapy. Owing to its rarity, the differential diagnosis is wide and requires a systematic approach for ruling out key morphologic mimics aided with SS18-SSX IHC and molecular confirmation because this distinction carries important therapeutic and prognostic implications. Due to the excellent concordance of SS18-SSX IHC results with FISH results as observed in our study, we would like to suggest inclusion of SS18-SSX in the diagnostic immunohistochemistry panel of all spindle cell sarcomas where synovial sarcoma is considered as a morphologic differential. 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.

Case Report : Undifferentiated Synovial Sarcoma Presenting as a Large Thoracic Mass: A Rare and Challenging Diagnosis

Background: Undifferentiated synovial sarcoma (USS) is a rare and aggressive subtype of soft tissue sarcoma. Its presentation as a large thoracic mass poses significant diagnostic and therapeutic challenges.  Case Presentation: A 34-year-old male presented with a three-month history of progressive chest pain and hemoptysis. Imaging studies revealed a large, cystic thoracic mass with pleural effusion. Initial serological testing suggested hydatid cyst, but subsequent testing revealed negative Echinococcus (Hydatid) IgG antibodies.  Diagnostic and Therapeutic Interventions: Repeat fine-needle aspiration cytology (FNAC) was deferred due to revised ultrasound findings indicating a solid fibrocystic vascular lesion. Bronchial artery embolization (BAE) was performed to control life- threatening hemorrhage. Thoracotomy and en-bloc mass excision were subsequently undertaken.  Histopathological Diagnosis: Histopathological examination of the resected specimen revealed undifferentiated synovial sarcoma and spindle cell sarcoma.  Clinical Implications: This case highlights the importance of correlating imaging and serological findings, managing vascular complications, and the efficacy of BAE in controlling hemorrhage. The significance of thoracotomy and mass excision in achieving diagnostic clarity and therapeutic success is underscored.  Conclusion: Undifferentiated synovial sarcoma presenting as a large thoracic mass poses significant diagnostic and therapeutic challenges. A multidisciplinary approach, incorporating imaging, serological testing, and surgical intervention, is crucial for achieving optimal patient outcomes.

DICER1 Syndrome in a 25-Year-Old Female: Autopsy Case Report of Mixed Sex Cord-Stromal and Primitive Sarcoma Tumors with Diverse Differentiation Patterns

Abstract Introduction/Objective DICER-1 syndrome is a rare disorder characterized by germline mutations in the DICER1 gene, known to confer a lifetime risk of developing a variety of benign and malignant pathologies. This syndrome typically affects young individuals, though it exhibits exceedingly variable and relatively low penetrance of the neoplastic manifestations. Methods/Case Report We report on a 25-year-old woman with a history of metastatic DICER-1 related mixed pattern sex-cord stromal tumor of the ovary and primitive sarcoma of the liver. Her treatment involved extensive surgeries, including oophorectomy, salpingectomy, and partial hepatectomy, and multiple cycles of chemotherapy. Antemortem surgical pathological analyses revealed a poorly differentiated, primitive sarcoma in the liver and a sex cord-stromal tumor with Sertoli-Leydig and juvenile granulosa cell tumor-like features. The liver tumor exhibited a primitive spindle cell sarcoma with anaplastic features as well as chondrosarcomatous and rhabdomyosarcomatous patterns, suggesting a primary DICER1-related sarcoma. Immunohistochemistry confirmed the tumor’s complex multilineage differentiation, showing variable positivity for CD99, vimentin, CD10, BCL2, and Glypican-3. Positivity for Desmin and MyoD1 was focal, while the tumor was negative for inhibin, calretinin, AE1/3, AFP, and beta-catenin, overall supporting a DICER1-associated sarcoma diagnosis. She eventually died from terminal cardiac arrest secondary to complications from her metastatic cancer. An autopsy revealed a significant abdominopelvic mass leading to hemoperitoneum and extensive organ involvement, highlighting the aggressive nature of DICER1-associated malignancies. Results (if a Case Study enter NA) NA Conclusion This case underscores the importance of recognizing the broad manifestations of DICER-1 syndrome for accurate diagnosis, genetic counseling, and tailored management. Highlighting tumor morphology and immunohistochemical features enriches our understanding of DICER-1 pathology, advancing diagnosis and treatment prospects for affected individuals.

DICER1 Mutations Enable Rare Tumor Formation

Abstract Introduction/Objective DICER1 is a tumor suppressor gene that imparts a slight increase in tumor formation when mutated. The protein plays a role in processing miRNA that silences transcription. Germline mutations of DICER1 predispose to tumors in a known set of organs and rarely in other locations. However the presence of additional genetic aberrations further increases the likelihood of tumor formation. Acting as a compounding factor, DICER1 mutations can present a constantly shifting cancer phenotype of affected patients. Of particular interest here is the development of both Pineoblastoma and Malignant spindle cell sarcoma in a young patient. Sarcomas are estimated to make up only 10% of pediatric cancers and Pineal masses only 3%. Methods/Case Report This case involves an 8 year old male with a history of Pineoblastoma who originally presented with slowly worsening ataxia. A screening ultrasound on following visits identified an abdominal mass that was confirmed with computed tomography. Subsequent biopsies showed malignant spindle cells arranged in a herringbone pattern. Additionally these cells displayed high mitotic activity and hyperchromatic nuclei. Surprisingly, they also demonstrated extramedullary hematopoiesis. Multiple stains were performed however no significant conclusion could be made. The appearance of this tumor and its rarity prompted a request for a Complete Comprehensive Sarcoma Panel via Next Generation Sequencing. This confirmed the presence of pathologic BRAF and DICER1 genes. From that the diagnosis of DICER1 associated Malignant Spindle Cell Sarcoma was made. BRAF V600E is the most common genetic variant and is seen in multiple cancers but only seen in 1-3% of sarcomas. Pathologic variants of the DICER1 gene exist on exons 13 and 25. The presence of these exon mutations in some way affect DICER1 protein function and compound the effects of the mutated BRAF gene. This situation is unique as such neoplasms are rarely found in the anterior abdominal wall and showcases the effects of DICER1 on rare tumor phenotypes. Results (if a Case Study enter NA) NA Conclusion Continuing research into both DICER1 protein pathways is essential for isolating a diagnosis and guiding treatment. It would seem screening images and genetic testing would benefit pediatric or even adult patients with common and rare cancers. Extra effort made toward this would not be outside the norm as personalized medicine is gradually becoming the standard for cancer treatment.

S2755 Spindle Cell Sarcoma of the Sigmoid Colon in a Patient Presenting With Acute Cholecystitis

S2755 Spindle Cell Sarcoma of the Sigmoid Colon in a Patient Presenting With Acute Cholecystitis

Un caso de exoftalmos progresivo en una niña de 5 años

Introduction: spindle cell sarcoma is a rare tumor, with little presentation in the literature. Soft tissue tumors constitute a heterogeneous group, requiring a multidisciplinary approach. Clinical case: 5-year-old schoolboy who goes to his pediatrician for exophthalmos. His mother refers a progressive proptosis in the left eye of 6 months of evolution. No loss of visual acuity, in the last weeks intermittent pain with eye movements. On examination proptosis of the left eye with intermittent tearing and vascular lesion in the temporal portion of the same eye, he presented restriction of left eye movements. He was referred to the hospital emergency department where a head CT scan (Figure 1,2) was performed, revealing a unilateral left retroorbital lesion measuring 28 x 14 mm, causing proptosis, mass effect on retroocular structures and loss of ocular sphericity. Given the findings in the imaging tests, it was decided surgical intervention by means of frontotemporal craniotomy, subsequently receiving complementary treatment with local radiotherapy. Due to negative molecular pathology studies, the result was finally interpreted as undifferentiated 'adult-type' spindle cell sarcoma. Conclusion: although undifferentiated spindle cell sarcoma is a rare pathology, it should be included in the differential diagnosis of retro-orbital pathologies. The objective of this case is to review the main characteristics of spindle cell sarcoma, given its rapid and aggressive form of presentation, in a rare tumor.

Computed tomography radiomics models of tumor differentiation in canine small intestinal tumors.

Radiomics models have been widely exploited in oncology for the investigation of tumor classification, as well as for predicting tumor response to treatment and genomic sequence; however, their performance in veterinary gastrointestinal tumors remains unexplored. Here, we sought to investigate and compare the performance of radiomics models in various settings for differentiating among canine small intestinal adenocarcinoma, lymphoma, and spindle cell sarcoma. Forty-two small intestinal tumors were contoured using four different segmentation methods: pre- or post-contrast, each with or without the inclusion of intraluminal gas. The mesenteric lymph nodes of pre- and post-contrast images were also contoured. The bin settings included bin count and bin width of 16, 32, 64, 128, and 256. Multinomial logistic regression, random forest, and support vector machine models were used to construct radiomics models. Using features from both primary tumors and lymph nodes showed significantly better performance than modeling using only the radiomics features of primary tumors, which indicated that the inclusion of mesenteric lymph nodes aids model performance. The support vector machine model exhibited significantly superior performance compared with the multinomial logistic regression and random forest models. Combining radiologic findings with radiomics features improved performance compared to using only radiomics features, highlighting the importance of radiologic findings in model building. A support vector machine model consisting of radiologic findings, primary tumors, and lymph node radiomics features with bin count 16 in post-contrast images with the exclusion of intraluminal gas showed the best performance among the various models tested. In conclusion, this study suggests that mesenteric lymph node segmentation and radiological findings should be integrated to build a potent radiomics model capable of differentiating among small intestinal tumors.

Spindle Cell Sarcoma of the Maxilla: A Rare Entity, Case Report, and Review of the Literature.

Spindle cell sarcoma (SCS) is a malignancy, with the most recent Surveillance, Epidemiology, and End Results (SEER) data citing a total of 250 reported cases occurring in the head and neck. Of these cases, none originated in the maxillofacial hard tissue. The diagnosis of SCS requires its differentiation from other sarcomas and spindle cell neoplasms. Therefore, a comprehensive review to reinforce its inclusion in oral and maxillofacial surgeons' differential diagnosis for osseous neoplastic pathology is desired. In the present case report, we have described a recurrent case of Maxillary Undifferentiated Spindle cell sarcoma in a 11 year old male child post chemoradiotherapy which was excised intoto successfully .

Analysis of three primary prostatic sarcoma cases and literature review.

The objective of this study is to evaluate the clinical presentations, diagnostic approaches, and treatment modalities for primary prostate sarcoma postradical prostatectomy, aiming to enhance its diagnosis and management. We retrospectively reviewed the clinical records of three male patients diagnosed with primary prostate sarcoma at Beijing Chaoyang Hospital, affiliated with Capital Medical University, from February 2014 to February 2024. All patients underwent transrectal prostate biopsies, which informed the decision to proceed with laparoscopic radical prostatectomies. After surgery, one patient received a combination of epirubicin and ifosfamide as immunotherapy, along with external beam radiotherapy. After comprehensive discussions regarding potential benefits and risks, the remaining two patients decided against undergoing radiotherapy and chemotherapy. Based on the pathological examination results, two patients were diagnosed with stromal sarcoma and one with spindle cell sarcoma, all classified as high-grade sarcomas. Immunohistochemical analysis showed that all three cases were positive for VIMENTIN, but other results did not show significant specificity. During the follow-up period, one patient died within 12 months, and two patients were lost to follow-up after 6 months. However, there were no evident signs of recurrence observed during the follow-up period. Primary prostate sarcoma is extremely rare and typically has a poor prognosis once diagnosed. Early diagnosis should be based on pathological and immunohistochemical testing results, followed by prompt surgical treatment and adjuvant radiotherapy and chemotherapy. Despite these measures, recurrence is common, underscoring the need for a detailed and appropriate treatment plan and systematic therapy for affected patients.

High Expression of miR-218-5p in the Peripheral Blood Stream and Tumor Tissues of Pediatric Patients with Sarcomas.

Sarcomas are malignant tumors that may metastasize and the course of the disease is highly aggressive in children and young adults. Because of the rare incidence of sarcomas and the heterogeneity of tumors, there is a need for non-invasive diagnostic and prognostic biomarkers in sarcomas. The aim of the study was to investigate the level of miR-218-5p in peripheral blood and tumor tissue samples of Ewing's sarcoma, osteosarcoma, spindle cell sarcoma patients, and healthy controls, and assessed whether the corresponding molecule was a diagnostic and prognostic biomarker. The study was performed patients (n = 22) diagnosed and treated with Ewing's sarcoma and osteosarcoma and in a control group of 22 healthy children who were matched for age, gender, and ethnicity with the patient group. The expression level of miR-218-5p in RNA samples from peripheral blood and tissue samples were analyzed using the RT-PCR and the expression level of miR-218-5p was evaluated by comparison with the levels in patients and healthy controls. The expression level of miR-218-5p was found to be statistically higher (3.33-fold, p = 0.006) in pediatric patients with sarcomas and when the target genes of miR-218-5p were investigated using the bioinformatics tools, the miR-218-5p was found as an important miRNA in cancer. In this study, the miR-218-5p was shown for the first time to have been highly expressed in the peripheral blood and tumor tissue of sarcoma patients. The results suggest that miR-218-5p can be used as a diagnostic and prognostic biomarker in sarcomas and will be evaluated as an important therapeutic target.

Malignant Peripheral Nerve Sheath Tumor, a Heterogeneous, Aggressive Cancer with Diverse Biomarkers and No Targeted Standard of Care: Review of the Literature and Ongoing Investigational Agents.

Malignant peripheral sheath tumor (MPNST) is a rare, aggressive form of soft-tissue sarcoma that presents a unique set of diagnostic and treatment challenges and is associated with major unmet treatment medical needs. The chief aim of this review is to consider the epidemiology, histology, anatomic distribution, pathologic signaling pathways, diagnosis, and management of MPNST, with a focus on potential targeted therapies. A subordinate objective was to establish benchmarks for the antitumor activity of such treatments. MPNST has an incidence of 1:100,000 in the general population and 1:3500 among patients with the inherited condition of neurofibromatosis-1. Spindle-cell sarcomas of neural-crest origin, MPNSTs are frequently situated in the extremities and pelvis/trunk, often at the confluence of large nerve roots and bundles. Highly copy-number aberrant and enriched in chromosome 8, MPNSTs have a complex molecular pathogenesis that likely involves the interplay of multiple signaling pathways, including Ras/AKT/mTOR/MAPK, EGFR, p53, PTEN, and PRC2, as well as factors in the tumor microenvironment. A combination of magnetic resonance imaging (MRI) and positron emission tomography with 18F-fluorodeoxyglucose (FDG-PET) enables comprehensive assessment of both morphology and metabolism, while MRI- and ultrasound-guided core needle biopsy can confirm histopathology. Although surgery with wide excisional margins is now the chief curative approach to localized disease, MPNST-specific survival has not improved in decades. For advanced and metastatic MPNST, radiation and chemotherapy (chiefly with anthracyclines plus ifosfamide) have somewhat promising but still largely uncertain treatment roles, chiefly in local control, downstaging, and palliation. No single druggable target has emerged, no objective responses have been observed with a number of targeted therapies (cumulative disease control rate in our review = 22.9-34.8%), and combinatorial approaches directed toward multiple signal transduction mechanisms are hallmarks of ongoing clinical trials. Despite advances in our understanding of the genetics and molecular biology of MPNST, further research is warranted to: (1) unravel the complex pathogenesis of this condition; (2) improve diagnostic yield; (3) delineate the appropriate roles of chemotherapy and radiation; and (4) develop a targeted therapy (or combination of such treatments) that is well tolerated and prolongs survival.

Expanding the Spectrum of NUTM1 -Rearranged Sarcoma : A Clinicopathologic and Molecular Genetic Study of 8 Cases.

Apart from the lethal midline carcinoma (NUT carcinoma), NUTM1 translocation has also been reported in mesenchymal tumors, but is exceedingly rare. Here, we describe a series of 8 NUTM1 -rearranged sarcomas to further characterize the clinicopathologic features of this emerging entity. This cohort included 2 males and 6 females with age ranging from 24 to 64 years (mean: 51y; median: 56y). Tumors occurred in the colon (2), abdomen (2), jejunum (1), esophagus (1), lung (1) and infraorbital region (1). At diagnosis, 6 patients presented with metastatic disease. Tumor size ranged from 1 to 10.5cm (mean: 6cm; median: 5.5 cm). Histologically, 4 tumors were composed of primitive small round cells to epithelioid cells intermixed with variable spindle cells, while 3 tumors consisted exclusively of small round cells to epithelioid cells and 1 tumor consisted predominantly of high-grade spindle cells. The neoplastic cells were arranged in solid sheets, nests, or intersecting fascicles. Mitotic activity ranged from 1 to 15/10 HPF (median: 5/10 HPF). Other features included rhabdoid phenotype (4/8), pronounced nuclear convolutions (2/8), prominent stromal hyalinization (2/8), focally myxoid stroma (1/8), foci of osteoclasts (1/8), and necrosis (1/8). By immunohistochemistry, all tumors showed diffuse and strong nuclear staining of NUT protein, with variable expression of pancytokeratin (AE1/AE3) (2/8), CK18 (1/8), CD99 (3/8), NKX2.2 (2/8), cyclin D1 (2/8), desmin (2/8), BCOR (2/8), S100 (1/8), TLE1 (1/8), and synaptophysin (1/8). Seven of 8 tumors demonstrated NUTM1 rearrangement by fluorescence in situ hybridization analysis. RNA-sequencing analysis identified MXD4::NUTM1 (3/7), MXI1::NUTM1 (3/7), and MGA::NUTM1 (1/7) fusions, respectively. DNA-based methylation profiling performed in 2 cases revealed distinct methylation cluster differing from those of NUT carcinoma and undifferentiated small round cell and spindle cell sarcomas. At follow-up (range: 4 to 24mo), 1 patient experienced recurrence at 8.5 months, 4 patients were alive with metastatic disease (5, 10, 11, and 24mo after diagnosis), 3 patients remained well with no signs of recurrence or metastasis (4, 6, and 12mo after diagnosis). Our study further demonstrated that NUTM1 -rearranged sarcoma had a broad range of clinicopathologic spectrum. NUT immunohistochemistry should be included in the diagnostic approach of monotonous undifferentiated small round, epithelioid to high-grade spindle cell malignancies that difficult to classify by conventional means. DNA-based methylation profiling might provide a promising tool in the epigenetic classification of undifferentiated sarcomas.

A rare case of fascicular spindle cell sarcoma of neck: a malignant peripheral nerve sheath tumor

A rare case of fascicular spindle cell sarcoma of neck: a malignant peripheral nerve sheath tumor

A case of a composite pheochromocytoma with a spindle cell sarcoma exhibiting aggressive behavior

A case of a composite pheochromocytoma with a spindle cell sarcoma exhibiting aggressive behavior

Low-grade undifferentiated sarcoma with MEIS1::NCOA2-rearrangement primary to the lung: a case report

BackgroundMEIS1::NCOA2 is a rare fusion gene that has been recently described in a subset of spindle cell rhabdomyosarcomas and multiple low-grade undifferentiated spindle cell sarcomas predominantly arising in the genitourinary and gynecologic tracts with no specific line of differentiation. We present the first documented case of this neoplasm arising as a lung primary tumor.Case PresentationA 74-year-old woman with a 40-year smoking history presented with a 2.1 × 1.7 cm lung nodule discovered on computed tomography (CT) scan. A biopsy and subsequent lobe resection were performed, as well as an extensive metastatic work up, which revealed no additional masses. No specific line of differentiation was found by immunohistochemical staining, and an RNA-based fusion panel revealed a MEIS1::NCOA2 fusion, at which point a diagnosis of Low-Grade Undifferentiated Sarcoma with MEIS1::NCOA2-Rearrangement was rendered.ConclusionsThis report represents the first diagnosis of this tumor primary to the lung, and provides additional insight into the origin and localization of these rare tumors.

Differential metabolic secretion between muscular dystrophy mouse-derived spindle cell sarcomas and rhabdomyosarcomas drives tumor type development.

The dystrophin gene (Dmd) is recognized for its significance in Duchenne muscular dystrophy (DMD), a lethal and progressive skeletal muscle disease. Some patients with DMD and model mice with muscular dystrophy (mdx) spontaneously develop various types of tumors, among which rhabdomyosarcoma (RMS) is the most prominent. By contrast, spindle cell sarcoma (SCS) has rarely been reported in patients or mdx mice. In this study, we aimed to use metabolomics to better understand the rarity of SCS development in mdx mice. Gas chromatography-mass spectrometry was used to compare the metabolic profiles of spontaneously developed SCS and RMS tumors from mdx mice, and metabolite supplementation assays and silencing experiments were used to assess the effects of metabolic differences in SCS tumor-derived cells. The levels of 75 metabolites exhibited differences between RMS and SCS, 25 of which were significantly altered. Further characterization revealed downregulation of nonessential amino acids, including alanine, in SCS tumors. Alanine supplementation enhanced the growth, epithelial mesenchymal transition, and invasion of SCS cells. Reduction of intracellular alanine via knockdown of the alanine transporter Slc1a5 reduced the growth of SCS cells. Lower metabolite secretion and reduced proliferation of SCS tumors may explain the lower detection rate of SCS in mdx mice. Targeting of alanine depletion pathways may have potential as a novel treatment strategy.NEW & NOTEWORTHY To the best of our knowledge, SCS has rarely been identified in patients with DMD or mdx mice. We observed that RMS and SCS tumors that spontaneously developed from mdx mice with the same Dmd genetic background exhibited differences in metabolic secretion. We proposed that, in addition to dystrophin deficiency, the levels of secreted metabolites may play a role in the determination of tumor-type development in a Dmd-deficient background.

Abstract 4255: A systematic framework for efficient generation of expandable patient-derived 3D sarcoma models

Abstract Introduction: Sarcomas are rare connective tissue tumors with over 100 described subtypes. High heterogeneity within and among sarcoma sub-entities and low incidence contribute to poor therapeutic success. Patient-derived 3D models (PDMs), i.e. organoids and spheroids, closely recapitulate features of the original tumor, e.g. cell-to-cell interaction, differentiation potential and heterogeneity. However, PDMs are rarely available or even lacking for most sarcoma sub-entities, constituting a major hurdle for sarcoma precision oncology and research. Here, we present a highly efficient and systematic framework to generate long-term 3D models for distinct sarcoma subtypes, which we developed within the HEROES-AYA consortium. Methods: Tumors were received directly after surgery and processed within 24 hours. After enzymatic dissociation, cell clumps were seeded in 384-well plates with and without Matrigel. Each tumor was cultivated on an array of 140 distinct culture conditions, differing in contribution and concentration of pathway inhibitors and activators. Organoid and spheroid growth was assessed over time via imaging and AI-based algorithms to identify best-growing conditions. Results: Initially, we combined Ewing sarcoma (EwS) secreted factors and potentially relevant cytokines to generate a matrix of 140 diverse media, named Media Test Plate (MTP). The MTP was tested on five EwS tumors, allowing the identification of optimal culture conditions with 100% efficiency. When transplanted in NSG mice, the established PDMs showed tumorigenicity potential and Ewing sarcoma-specific CD99 marker expression. The MTP was then tested on four synovial sarcomas (SyS) and five myxoid liposarcomas with a 75% and 50% success rate, respectively. The optimal media, as identified by MTP, allowed the cultivation of one EwS and one SyS out of two, respectively, even with limited cell count. Additional PDMs generated include one undifferentiated, one alveolar soft tissue and one spindle cell sarcoma. Established cultures were characterized by Ki67 positivity, ranging from 40% to 70%, and expression of sarcoma subtype-specific markers. EwS models resulted 100% CD99 positive, while TLE1 positivity in SyS models was ≈90%. DNA and RNA sequencing of PDMs will show whether they resemble the genetic and transcriptional features of the original tumors. Conclusions: We here present a novel systematic protocol to generate organoids and spheroids from different sarcoma subtypes. To date, no such systematic protocol is available for sarcoma models generation. Our success rate is comparable to the one of intestinal and pancreatic organoids and exceeds those of 2D and PDX sarcoma cultures, which is ≈20%. Current work aims to adapt the MTP to a broad range of sarcoma subtypes, including rare entities. The efficient generation of expandable PDMs from a wide range of sarcomas will further fuel basic and translational research. Citation Format: Claudia Dagostino, Waqar Hussain, Jasmina Paluncic, Marcelo Zoccoler, Jessica Pablik, Daniela Richter, Lisanne Knol, Ana Banito, Johanna Wagner, Ivona Mateska, Daniel E. Stange, Ina Oehme, Stephan Richter, Stefan M. Pfister, Stefan Fröhling, Claudia Scholl, Jürgen Weitz, Klaus-Dieter Schaser, Christoph Heining, Hanno Glimm, Claudia R. Ball. A systematic framework for efficient generation of expandable patient-derived 3D sarcoma models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4255.

Neutrophil-to-lymphocyte ratio for the prediction of soft tissue sarcomas response to pre-operative radiation therapy

Purpose/ObjectiveThis study aims to assess the prognostic value of the neutrophil-to-lymphocyte ratio (NLR) in soft tissue sarcomas (STS) treated with pre-operative hypofractionated radiotherapy (HFRT). Materials/MethodsThis retrospective analysis included patients treated with pre-operative HFRT of 30 Gy in 5 fractions between 2016 and 2023. Clinical, demographic, and complete blood count (CBC) data were collected. NLR was calculated by dividing the absolute neutrophil count by the absolute lymphocyte count. Only patients with CBCs conducted within 6 months after radiotherapy were included. Cox proportional-hazard regression models were used to assess the impact of NLR and different variables on outcomes. Kaplan Meier were used to illustrate survival curves. A p-value < 0.05 was considered significant, and 95 % confidence intervals (CI) were employed. ResultsA total of 40 patients received HFRT and had CBCs within 6 months after radiotherapy. There were 17 (42.5 %) females and 23 (57.5 %) males with a mean age of 66 years. The mean largest tumor size dimension was 7.1 cm, and the mean NLR post-RT was 5.3. The most frequent histological subtypes were myxofibrosarcoma (17.5 %), pleomorphic spindle cell sarcoma (10 %), leiomyosarcoma (7.5 %), and myxoid liposarcoma (5 %). The median follow-up period was 15.4 months. From all patients, 14 patients had disease progression, 12 metastatic disease and 3 died of disease. Multivariable Cox proportional-hazards regression analysis displayed that a higher post-RT NLR was associated with worse disease-free survival (DFS) (HR: 1.303 [1.098–1.548], p = 0.003), and distant metastasis-free survival (DMFS) (HR: 1.38 [1.115–1.710], p = 0.003). Moreover, post-NLR ≥ 4 as a single variable was associated with worse DFS, DMFS, but not worse local recurrence or overall survival. ConclusionThis study is the first to evaluate NLR as a prognostic biomarker in STS patients treated with pre-operative radiotherapy. A higher NLR after pre-operative radiotherapy was associated with increased disease progression.