Biology and Management of Undifferentiated Pleomorphic Sarcoma, Myxofibrosarcoma, and Malignant Peripheral Nerve Sheath Tumors: State of the Art and Perspectives

Collagen modification remodels the sarcoma tumor microenvironment and promotes resistance to immune checkpoint inhibition

Molecular mechanisms underlying immune checkpoint inhibitor (ICI) response heterogeneity in solid tumors, including soft tissue sarcomas (STS), remain poorly understood. Herein, we demonstrate that the collagen-modifying enzyme, procollagen-lysine,2-oxoglutarate 5-dioxygenase 2 (Plod2), which is over-expressed in many tumors relative to normal tissues, promotes immune evasion in undifferentiated pleomorphic sarcoma (UPS), a relatively common and aggressive STS subtype. This finding is consistent with our earlier observation that Plod2 promotes tumor metastasis in UPS, and its enzymatic target, collagen type VI (ColVI), enhances CD8+ T cell dysfunction. We determined that genetic and pharmacologic inhibition of Plod2 with the pan-Plod transcriptional inhibitor minoxidil, reduces UPS growth in an immune competent syngeneic transplant system and enhances the efficacy of anti-Pd1 therapy. These findings suggest that PLOD2 is an actionable cancer target and its modulation could augment immunotherapy responses in patients with UPS, and potentially other sarcomas and carcinomas.

Sural flap reconstruction of lateral malleolus following undifferentiated pleomorphic sarcoma resection with 1-year follow-up

We report a case of a 54-year-old female who presents with a gradually expanding mass at the right lateral malleolus. The diagnosis of undifferentiated pleomorphic sarcoma was made after a histopathological examination of the mass following a wide tumor excision. The defected soft tissue area was reconstructed using a local flap, reverse sural artery flap. Following the surgical management, multiple radiotherapy sessions were completed. The patient's follow-up result showed no signs of local recurrence or metastasis, and the wound was well-healed with no complications other than paresthesia in a small area at the posterolateral aspect of the ankle under the lateral malleolus. This case represents a rare form of malignant neoplasm and emphasizes the effectiveness and safety of the reverse sural artery flap reconstruction technique, especially in places where microsurgery is unavailable or when the patient's status does not allow for prolonged anesthesia.

Giant Myxofibrosarcoma in the Lower Limb: An Overview of Diagnostic and Clinical Management

Myxofibrosarcoma (MFS), an aggressive soft tissue sarcoma, is one of the undifferentiated pleomorphic sarcomas; it has a low incidence, affecting people in the sixth to eighth decades of life. It usually involves the extremities and is painless with a slow-growing pattern. Based on the case of a 52-year-old female patient who presented with a painful, massive, rapid-growing, ulcerated tumor of the anterior surface of the left thigh, we performed a literature review regarding the current standard of care for patients with MFS. Computed tomography examination, followed by magnetic resonance imaging and surgical biopsy with histopathological examination, confirmed the diagnosis and the presence of lung and inguinal lymph node metastases. Due to the rapid-growing pattern and the local aggressiveness, our tumor board team recommended emergency excisional surgery, with subsequent reconstructive procedures followed by referral to an oncological center. This review emphasizes the importance of proper and rapid diagnosis, followed by multidisciplinary management, for MFS cases with atypical presentation and distal metastases to improve overall outcomes.

Radiotherapy and surgery remain effective treatment options for retroperitoneal MPNST: a retrospective study based on SEER database

Introduction

The proportion of retroperitoneal malignant peripheral nerve sheath tumours (RMPNST) in retroperitoneal tumors is less than 5%, but the mortality rate is very high. However, there is no relevant research focused on RMPNST only.

Methods

We retrospectively analyzed data from the SEER database of patients with primary RMPNST from 2000 to 2019, by leveraging the advantages of the Seer database, we can explore the prognosis of such rare diseases. Kaplan-Meier method was used to construct the survival curve, and cox regression model was used to analyze the factors affecting the prognosis of patients. In addition, a model was developed to distinguish high-risk and low-risk patients.

Results

This study included a total of 52 patients, with a median survival time of 39 months (95% CI 12.740-65.260) and a 5-year survival rate of 44.2% (95% CI 0.299-0.565). Radiotherapy (p = 0.004, OR: 1.475, 95% CI 0.718-3.033), metastasis disease (p = 0.002, OR: 5.596, 95% CI 2.449-47.079) and surgery (p = 0.003, OR: 5.003, 95% CI 0.011-0.409) were associated with overall survival (OS). The 5-year distant metastasis rate was 36% (95% CI 0.221-0.499). We used the above risk factors to separate patients into high and low groups and evaluate the results through the receiver operating characteristic (ROC) curve. This model is beneficial for guiding the selection of treatment strategies.

Conclusion

The majority of RMPNST patients have a good prognosis after surgery, and the establishment of high-low group is helpful for clinical decision-making.

Clear surgical margins as a prognostic indicator for disease recurrence, with no impact on survival rates in patients with myxofibrosarcoma

Myxofibrosarcoma presents an infiltrating growth pattern that results in a high tendency for local recurrence. Clear margin resection is challenging because of microscopic infiltration. The purpose of the present study was to analyze the overall and disease-free survival rates of patients with myxofibrosarcoma and the prognostic factors that determine both survival and disease recurrence. Among the 111 patients included in our study, the 5-year overall survival rate was 65.5%. An age of more than 65 years (hazard ratio [HR] 1.9 [95% confidence interval (CI) 1.4-5.6]; p < 0.001), a tumor size of more than 5 cm (HR 2.8 [95% CI 0.9-8.1]; p = 0.049) and the G3 tumor grade (HR 14.1 [95% CI 2.1-105.0]; p < 0.001) negatively affected overall survival. The 5-year recurrence-free survival rate was 49.4%. R1/R2-type resection (HR 2.4 [95% CI 1.0-5.6]; p = 0.048) had a detrimental effect on tumor recurrence. Clear margins had a positive impact on recurrence-free survival, but did not significantly affect overall patient survival, suggesting that other factors may play a more significant role in determining patient outcomes. A surgical margin of 2 mm was not sufficient to significantly influence the incidence of recurrence. Consequently, a wider surgical margin may be necessary to reduce the risk of myxofibrosarcoma recurrence.

Chronic kidney disease with malignant peripheral nerve sheath tumor of the ureter: a case report

Malignant peripheral nerve sheath tumors (MPNSTs) are a complex group of malignant tumors originating from nerve cells or benign peripheral nerve sheath tumors and are commonly found in major plexus/nerve root sites such as the limbs, head, and neck. Malignant peripheral nerve sheath tumors originating in the ureter are extremely rare. Herein, we report the case of a 63-year-old patient with a malignant peripheral nerve sheath tumor of the right ureter who underwent laparoscopic radical resection of the right kidney and ureter. The patient also had stage 5 chronic kidney disease (CKD). Therefore, chemotherapy and radiotherapy were not considered. No tumor recurrence was observed during the follow-up period.

Autophagy, a double-edged sword for oral tissue regeneration

BACKGROUND

Oral health is of fundamental importance to maintain systemic health in humans. Stem cell-based oral tissue regeneration is a promising strategy to achieve the recovery of impaired oral tissue. As a highly conserved process of lysosomal degradation, autophagy induction regulates stem cell function physiologically and pathologically. Autophagy activation can serve as a cytoprotective mechanism in stressful environments, while insufficient or over-activation may also lead to cell function dysregulation and cell death.

AIM OF REVIEW

This review focuses on the effects of autophagy on stem cell function and oral tissue regeneration, with particular emphasis on diverse roles of autophagy in different oral tissues, including periodontal tissue, bone tissue, dentin pulp tissue, oral mucosa, salivary gland, maxillofacial muscle, temporomandibular joint, etc. Additionally, this review introduces the molecular mechanisms involved in autophagy during the regeneration of different parts of oral tissue, and how autophagy can be regulated by small molecule drugs, biomaterials, exosomes/RNAs or other specific treatments. Finally, this review discusses new perspectives for autophagy manipulation and oral tissue regeneration.

KEY SCIENTIFIC CONCEPTS OF REVIEW

Overall, this review emphasizes the contribution of autophagy to oral tissue regeneration and highlights the possible approaches for regulating autophagy to promote the regeneration of human oral tissue.

Oncogene-induced matrix reorganization controls CD8+ T cell function in the soft-tissue sarcoma microenvironment

CD8+ T cell dysfunction impedes antitumor immunity in solid cancers, but the underlying mechanisms are diverse and poorly understood. Extracellular matrix (ECM) composition has been linked to impaired T cell migration and enhanced tumor progression; however, impacts of individual ECM molecules on T cell function in the tumor microenvironment (TME) are only beginning to be elucidated. Upstream regulators of aberrant ECM deposition and organization in solid tumors are equally ill-defined. Therefore, we investigated how ECM composition modulates CD8+ T cell function in undifferentiated pleomorphic sarcoma (UPS), an immunologically active desmoplastic tumor. Using an autochthonous murine model of UPS and data from multiple human patient cohorts, we discovered a multifaceted mechanism wherein the transcriptional coactivator YAP1 promotes collagen VI (COLVI) deposition in the UPS TME. In turn, COLVI induces CD8+ T cell dysfunction and immune evasion by remodeling fibrillar collagen and inhibiting T cell autophagic flux. Unexpectedly, collagen I (COLI) opposed COLVI in this setting, promoting CD8+ T cell function and acting as a tumor suppressor. Thus, CD8+ T cell responses in sarcoma depend on oncogene-mediated ECM composition and remodeling.

Bulky malignant peripheral nerve sheath tumour of the left thigh in a pregnant woman presenting with a pathological fracture of the proximal femur

Malignant peripheral nerve sheath tumour (MPNST) is an aggressive soft tissue sarcoma with a poor prognosis, affecting most commonly the extremities. The lungs constitute the most frequent location for distant metastases. Half of all MPNSTs arise in patients with neurofibromatosis type 1, while approximately 10% are radiation induced and the rest are sporadic.The authors present a pregnant woman in her 40s with a sporadic MPNST of the lower limb and with lung metastases at diagnosis. Treatment consisted of interilioabdominal amputation, followed by adjuvant chemotherapy. Partial response and disease stabilisation were achieved with chemotherapy.Surgical resection with negative margins is the only potentially curative therapy, while radiation therapy and chemotherapy might be useful in the neoadjuvant or adjuvant setting, but their advantage in survival is not demonstrated. In the reported case, chemotherapy permitted the achievement of partial response and stabilisation of the disease.

Undifferentiated Pleomorphic Sarcoma of the Distal Thigh: A Case Report

The undifferentiated pleomorphic sarcoma (UPS) is a rare malignant tumor of mesenchymal origin. Poorly differentiated tumor cells, which might take the form of giant cells, histiocytes, or spindle-shaped cells, make up the UPS variant of sarcomas. If soft tissue tumors enlarge and turn malignant, they may become an issue. Sarcoma is diagnosed by several tests, such as a physical examination, MRI, CT scan, or ultrasound. A biopsy yields information regarding the grade and subtype of the sarcoma and is required for a clear diagnosis. Chemotherapy, radiation therapy, and broad-margin excision are the standard treatments for cancers of the bone. UPS often appears in people between 50 and 70 years old. Yet, here we report a 40-year-old male diagnosed with UPS. Our goal is to discuss how unique our case is in comparison to others, as well as the available diagnostic and therapeutic alternatives in such cases.

Development and external validation of a machine learning model for prediction of survival in undifferentiated pleomorphic sarcoma

PURPOSE

Machine learning (ML) algorithms to predict cancer survival have recently been reported for a number of sarcoma subtypes, but none have investigated undifferentiated pleomorphic sarcoma (UPS). ML is a powerful tool that has the potential to better prognosticate UPS.

METHODS

The Surveillance, Epidemiology, and End Results (SEER) database was queried for cases of histologically confirmed undifferentiated pleomorphic sarcoma (UPS) (n = 665). Patient, tumor, and treatment characteristics were recorded, and ML models were developed to predict 1-, 3-, and 5-year survival. The best performing ML model was externally validated using an institutional cohort of UPS patients (n = 151).

RESULTS

All ML models performed best at the 1-year time point and worst at the 5-year time point. On internal validation within the SEER cohort, the best models had c-statistics of 0.67-0.69 at the 5-year time point. The Multi-Layer Perceptron Neural Network (MLP) model was the best performing model and used for external validation. Similarly, the MLP model performed best at 1-year and worst at 5-year on external validation with c-statistics of 0.85 and 0.81, respectively. The MLP model was well calibrated on external validation. The MLP model has been made publicly available at https://rachar.shinyapps.io/ups_app/ .

CONCLUSION

Machine learning models perform well for survival prediction in UPS, though this sarcoma subtype may be more difficult to prognosticate than other subtypes. Future studies are needed to further validate the machine learning approach for UPS prognostication.

Survival outcomes of malignant peripheral nerve sheath tumors (MPNSTs) with and without neurofibromatosis type I (NF1): a meta-analysis

INTRODUCTION

Malignant peripheral nerve sheath tumors (MPNSTs) are malignancies that demonstrate nerve sheath differentiation in the peripheral nervous system. They can occur sporadically or be associated with neurofibromatosis type 1 (NF1), an autosomal dominant neurocutaneous disorder, with up to 13% of patients developing MPNSTs in their lifetimes. Previous studies have suggested conflicting findings regarding the prognosis of NF1 for patients with MPNSTs. The elucidation of NF1 as an independent prognostic factor on mortality has implications for clinical management. We aim to investigate the role of NF1 status as an independent prognostic factor of overall survival (OS) and disease-specific survival (DSS) in MPNSTs.

METHODS

An electronic literature search of PubMed and MEDLINE was performed on studies reporting OS or DSS outcomes of MPNSTs with and without NF1. A grey literature search by reviewing bibliographies of included studies and review articles was performed to find pertinent studies. Data was extracted and assessed in accordance with the PRISMA guidelines. A meta-analysis was performed to calculate hazard ratios (HRs) using a random-effects model. The primary and secondary outcomes were all-cause and disease-specific mortality, respectively, with NF1 as an independent prognostic factor of interest.

RESULTS

A total of 59 retrospective studies involving 3602 patients fulfilled the inclusion criteria for OS analysis, and 23 studies involving 704 MPNST patients were included to evaluate DSS outcomes. There was a significant increase in the hazard of all-cause mortality (HR 1.63, 95% CI 1.45 to 1.84) and disease-specific mortality (HR 1.52, 95% CI 1.24 to 1.88) among NF1 as compared to sporadic cases. Subgroup analyses and meta-regression showed that this result was consistent regardless of the quality of the study and year of publication.

CONCLUSION

NF1 is associated with a substantially higher risk of all-cause and disease-specific mortality. This finding suggests that closer surveillance is required for NF1 patients at risk of developing MPNSTs.

Novel PD-L1- and collagen-expressing patient-derived cell line of undifferentiated pleomorphic sarcoma (JBT19) as a model for cancer immunotherapy

Soft tissue sarcomas are aggressive mesenchymal-origin malignancies. Undifferentiated pleomorphic sarcoma (UPS) belongs to the aggressive, high-grade, and least characterized sarcoma subtype, affecting multiple tissues and metastasizing to many organs. The treatment of localized UPS includes surgery in combination with radiation therapy. Metastatic forms are treated with chemotherapy. Immunotherapy is a promising treatment modality for many cancers. However, the development of immunotherapy for UPS is limited due to its heterogeneity, antigenic landscape variation, lower infiltration with immune cells, and a limited number of established patient-derived UPS cell lines for preclinical research. In this study, we established and characterized a novel patient-derived UPS cell line, JBT19. The JBT19 cells express PD-L1 and collagen, a ligand of the immune checkpoint molecule LAIR-1. JBT19 cells can form spheroids in vitro and solid tumors in immunodeficient nude mice. We found JBT19 cells induce expansion of JBT19-reactive autologous and allogeneic NK, T, and NKT-like cells, and the reactivity of the expanded cells was associated with cytotoxic impact on JBT19 cells. The PD-1 and LAIR-1 ligand-expressing JBT19 cells show ex vivo immunogenicity and effective in vivo xenoengraftment properties that can offer a unique resource in the preclinical research developing novel immunotherapeutic interventions in the treatment of UPS.

Is the Thickness of the Margin Associated With Local Recurrence and Survival in Patients With Myxofibrosarcoma?

BACKGROUND

Myxofibrosarcoma (MFS) is a spectrum of aggressive soft tissue fibroblastic neoplasms characterized by variable myxoid stroma, pleomorphism, and a distinctive curved vascular pattern; these tumors are associated with a high likelihood of recurrence. Better local tumor control (a tumor-free margin) is believed to be important to minimize the risk of recurrence, but the effect of surgical resection margin status on local recurrence and survival in MFS is not as well-characterized as it might be.

QUESTIONS/PURPOSES

(1) Is margin width associated with local recurrence? (2) Is there a relationship between greater margin thickness and improved overall and disease-free survival (DFS)? (3) Is worsening French Federation of Cancer Centers grade associated with local recurrence and poorer overall survival?

METHODS

Using a database of patients with bone and soft tissue tumors at a tertiary university hospital, we retrospectively reviewed the medical records of 282 patients who had soft tissue sarcomas and who had been surgically treated by a multidisciplinary bone and soft tissue tumor care team between January 2010 and December 2021. Of these 282 patients, 38 were identified as having MFS. Patients who received surgical care for MFS outside our institution (unplanned resection) (four patients) and whose surgical margins were not reported as microscopic numerical data (10) were excluded from the analysis. We estimated survival and local recurrence and examined factors potentially influencing these outcomes. Patient demographics, tumor characteristics, surgical margin distance (in mm), and disease-related outcomes were recorded. The minimum follow-up was 3 months (median 41.5 months, range 3 to 128 months).

RESULTS

Overall 1-year local recurrence-free rates were 66.7% (95% CI 50% to 88%). Patients with positive margins were more likely to have local recurrence than patients with negative margins (HR 10.91 [95% CI 2.61 to 45.66]; p = 0.001). Patients with an inadequate margin (positive margin or a negative margin of 1 mm or less) had a greater risk of local recurrence (HR 9.96 [95% CI 1.22 to 81.44]; p = 0.032). Patients with positive margins or margins less than or equal to 1 mm had worse 2-year local recurrence-free survival than did those with margins of greater than 1 mm (46.9% [95% CI 16% to 76%] versus 91.7% [95% CI 75% to 100%]; p = 0.005). The mean overall survival was 98 months (95% CI 77.2 to 118.8). The Kaplan-Meier overall 1-, 2- and 5-year estimated rates of survival were 88% (95% CI 75% to 100%), 79.2% (95% CI 64.5% to 97.2%), and 73.5% (95% CI 57.2 % to 94.5%), respectively. Positive surgical margins were associated with decreased overall survival (HR 6.96 [95% CI 1.39 to 34.89]; p = 0.018). There was a mean DFS time of 4.25 months (95% CI 0.92 to 7.59) in microscopically positive patients, 75.5 months (95% CI 37.47 to 113.53) in patients with margins 1 mm or less, and 118 months (95% CI 99.23 to 136.77) in patients with margins over 1 mm. There was a statistical difference between DFS times according to surgical margin classification (p < 0.001). With the numbers we had, we could not detect any difference between the histologic grades determined by the French Federation of Cancer Centers grading system in terms of local recurrence (HR 3.80 [95% CI 0.76 to 18.94]; p = 0.103) and overall survival (HR 6.91 [95% CI 0.79 to 60.13]; p = 0.080). Tumor size was the prognostic factor associated with a higher local recurrence rate among all factors analyzed as univariate (HR 1.18 [95% CI 1.05 to 1.32]; p = 0.004).

CONCLUSION

A surgical procedure with a sufficient negative surgical margin distance appears to be associated with a lower proportion of patients who experience a local recurrence and is associated with overall patient survival. It is difficult to define what a sufficient margin is, but in our patients, it appears to be greater than 1 mm.Level of Evidence Level III, therapeutic study.

FOXM1 promotes neurofibromatosis type 1-associated malignant peripheral nerve sheath tumor progression in a NUF2-dependent manner

Malignant peripheral nerve sheath tumors (MPNSTs) are aggressive soft-tissue sarcomas characterized by poor prognosis and low drug response rates. Traditional chemo/radiotherapies show only mild benefits for patients with MPNSTs, and no targeted therapy is available in the clinic. A better understanding of the molecular background of MPNSTs is critical for the development of effective targeted therapies. Forkhead box M1 (FOXM1) has been implicated in the progression of many human malignancies, though its role in MPNSTs is unclear. In this study, using four Gene Expression Omnibus (GEO) datasets and a tissue microarray, we demonstrated that FOXM1 upregulation was associated with poor prognosis in patients with MPNSTs. FOXM1 overexpression and knockdown regulated the proliferation and colony formation of MPNST cells. Using bioinformatics analysis and luciferase reporter assays, we identified NUF2 as a direct downstream target of FOXM1. Both in vitro and in vivo experiments demonstrated that the induction of MPNST cell proliferation by FOXM1 was dependent on elevated NUF2 expression, as NUF2 knockdown abolished the FOXM1-induced proliferation of MPNST cells. Our study showed that the FOXM1-NUF2 axis mediates human MPNST progression and could be a potential therapeutic target.

A Rare Presentation of Undifferentiated Pleomorphic Sarcoma in the Subpectoral Space

Soft tissue sarcomas (STS) are often described as asymptomatic, rapidly expanding masses, particularly in the extremities or trunk. Undifferentiated pleomorphic sarcoma (UPS), a high-grade variant of STS, ranks as the second most prevalent subtype in the United States. It predominantly affects males between their fifth and seventh decades. Its often benign symptomatology, however, can lead to initial misdiagnosis and subsequent mismanagement. We present the case of a 57-year-old Caucasian male, previously in good health, who experienced a recurring subpectoral lesion causing discomfort and mass-related effects. Initial management included incision and drainage, which provided temporary relief. The biopsy revealed a diagnosis of grade 3 UPS. The lesion's recurrence two months later was accompanied by local invasion into adjacent skin and musculature as well as metastasis to the right hemiliver. A comprehensive understanding of UPS among medical professionals is vital for accurate diagnosis and facilitating prompt intervention to prevent avoidable complications and optimize patient outcomes.

Retroperitoneal undifferentiated pleomorphic sarcoma with total nephrectomy: a case report and literature review

Background

Undifferentiated pleomorphic sarcoma (UPS) is a highly malignant soft tissue sarcoma with a poor prognosis and no clear effective clinical means for treatment, and there has been no significant progress in research within this field in recent years. This study aimed to investigate the epidemiology, etiology, clinical features, diagnostic modalities, various treatment modalities, and prognosis of retroperitoneal undifferentiated pleomorphic sarcoma and to contribute to the clinical management of this type of disease. In this study, we report a case of undifferentiated pleomorphic sarcoma with a primary origin in the retroperitoneum. Undifferentiated pleomorphic sarcoma occurring in the retroperitoneum is rarely reported.

Case description

A 59-year-old man with abdominal distension and pain for 4 months presented to our hospital after the failure of conservative treatment. A 9.6 cm by 7.4 cm mass in the left retroperitoneum was found on a CT scan of the whole abdomen with three degrees of enhancement. After surgical treatment, the tumor and the left kidney were completely removed, and pathological examination and genetic sequencing showed an apparent undifferentiated pleomorphic sarcoma. The patient subsequently declined follow-up treatment and is currently alive and well.

Conclusions

At the current level of clinical technology, the treatment of undifferentiated pleomorphic sarcoma is still in the exploratory stage, and the scarcity of clinical cases of this disease may have hindered the acquisition of clinical trials and research data for this disease. At present, the first choice of treatment for undifferentiated pleomorphic sarcoma is still radical resection. In the existing clinical studies, there are no strong data to support the effect of preoperative neoadjuvant chemoradiotherapy and adjuvant chemoradiotherapy in clinical practice. Similar to other diseases, the use of radiotherapy and chemotherapy before and after surgery may be a potential treatment for this disease in the future. Targeted therapy for this disease still needs further exploration, and we need more reports on related diseases to promote future treatment and research on this disease.

Integrating analysis of proteome profile and drug screening identifies therapeutic potential of MET pathway for the treatment of malignant peripheral nerve sheath tumor

BACKGROUND

Malignant peripheral nerve sheath tumor (MPNST) is an aggressive sarcoma with a poor prognosis that requires novel therapeutic agents. Proteome information is useful for identifying new therapeutic candidates because it directly reflects the biological phenotype. Additionally, in vitro drug screening is an effective tool to identify candidate drugs for common cancers. Hence, we attempted to identify novel therapeutic candidates for MPNST by integrating proteomic analysis and drug screening.

METHODS

We performed comprehensive proteomic analysis on 23 MPNST tumor samples using liquid chromatography-tandem mass spectrometry to identify therapeutic targets. We also conducted drug screening of six MPNST cell lines using 214 drugs.

RESULTS

Proteomic analysis revealed that the MET and IGF pathways were significantly enriched in the local recurrence/distant metastasis group of MPNST, whereas drug screening revealed that 24 drugs showed remarkable antitumor effects on the MPNST cell lines. By integrating the results of these two approaches, MET inhibitors, crizotinib and foretinib, were identified as novel therapeutic candidates for the treatment of MPNST.

CONCLUSIONS

We successfully identified novel therapeutic candidates for the treatment of MPNST, namely crizotinib and foretinib, which target the MET pathway. We hope that these candidate drugs will contribute to the treatment of MPNST.

Unveiling the Genomic Basis of Chemosensitivity in Sarcomas of the Extremities: An Integrated Approach for an Unmet Clinical Need

Myxofibrosarcoma (MFS) and undifferentiated pleomorphic sarcoma (UPS) can be considered as a spectrum of the same disease entity, representing one of the most common adult soft tissue sarcoma (STS) of the extremities. While MFS is rarely metastasizing, it shows an extremely high rate of multiple frequent local recurrences (50-60% of cases). On the other hand, UPS is an aggressive sarcoma prone to distant recurrence, which is correlated to a poor prognosis. Differential diagnosis is challenging due to their heterogeneous morphology, with UPS remaining a diagnosis of exclusion for sarcomas with unknown differentiation lineage. Moreover, both lesions suffer from the unavailability of diagnostic and prognostic biomarkers. In this context, a genomic approach combined with pharmacological profiling could allow the identification of new predictive biomarkers that may be exploited for differential diagnosis, prognosis and targeted therapy, with the aim to improve the management of STS patients. RNA-Seq analysis identified the up-regulation of MMP13 and WNT7B in UPS and the up-regulation of AKR1C2, AKR1C3, BMP7, and SGCG in MFS, which were confirmed by in silico analyses. Moreover, we identified the down-regulation of immunoglobulin genes in patient-derived primary cultures that responded to anthracycline treatment compared to non-responder cultures. Globally, the obtained data corroborated the clinical observation of UPS as an histotype refractory to chemotherapy and the key role of the immune system in determining chemosensitivity of these lesions. Moreover, our results confirmed the validity of genomic approaches for the identification of predictive biomarkers in poorly characterized neoplasms as well as the robustness of our patient-derived primary culture models in recapitulating the chemosensitivity features of STS. Taken as a whole, this body of evidence may pave the way toward an improvement of the prognosis of these rare diseases through a treatment modulation driven by a biomarker-based patient stratification.

Ultrasonographic diagnosis of primary hepatic undifferentiated pleomorphic sarcoma

OBJECTIVE

To explore the ultrasonographic features of primary hepatic undifferentiated pleomorphic sarcoma (UPS) to increase the rate of accurate clinical diagnosis.

METHODS

We analyzed all (n = 7) primary hepatic UPS cases who attended Our Hospital from 2010 to 2021 in terms of morphology, size, echogenicity, borders, blood flow signal, posterior echoes, and other ultrasonographic features.

RESULTS

All studied masses were solitary and mainly invaded one lobe of the liver. All the masses had diameters exceeding 5.0 cm and were nonencapsulated. They mostly had clear borders and regular morphologies (6 of 7 [85.7%]). Echogenicity was hypoechoic (2 of 7 [28.6%]) or heterogeneous (5 of 7 [71.4%]). Echogenicity was enhanced at the posterior aspect in all cases. None of the cases exhibited calcification, but some showed mass liquefaction (2 of 7 [28.6%]). Blood flow signal from the mass was rich (2 of 7 [28.6%]), mild (2 of 7 [28.6%]) or minimal (3 of 7 [42.9%]). One case in this study underwent CEUS. The margins and the internal septa, and mural or septal nodules of the mass showed mild hyperenhancement in the arterial phase and portal venous phase, but mild hypoenhancement in late phase. There were large nonenhancing areas in all three phases.

CONCLUSION

When ultrasonography reveals a solitary, relatively large, regular, and nonencapsulated mass, primary hepatic UPS should be a differential diagnosis. Combining clinical findings with imaging modalities can increase the likelihood of an accurate diagnosis.

Dramatic response to entrectinib in a patient with malignant peripheral nerve sheath tumor harboring novel SNRNP70-NTRK3 fusion gene

Neurotropic tropomyosin receptor kinase (NTRK) gene rearrangements have been reported in limited cases of sarcomas; however, to date, there has been only one report of such rearrangements in malignant peripheral nerve sheath tumors (MPNSTs). Herein, we describe a 51-year-old male patient with a buttock tumor arising from the sciatic nerve, which was diagnosed as MPNST with positive S-100 staining, negative SOX10 staining, and loss of trimethylation at lysine 27 of histone H3 (H3K27me3) confirmed by immunohistochemistry. Soon after the resection of the primary tumor, the patient was found to have pulmonary and lymph node metastases. Chemotherapy with eribulin and trabectedin showed limited effects. However, the patient responded rapidly to pazopanib, but severe side effects caused discontinuation of the treatment. RNA panel testing revealed a novel fusion gene between Small Nuclear Ribonucleoprotein U1 Subunit 70 (SNRNP70) gene and NTRK3 gene. Furthermore, loss of NF1, SUZ12, and CDKN2A genes was confirmed by DNA panel testing, which is compatible with a histological diagnosis of MPNST. SNRNP70 possesses a coiled-coiled domain and seems to induce constitutive activation of NTRK3 through dimerization. In fact, immunohistochemistry revealed diffuse staining of pan-TRK within tumor cells. Treatment with entrectinib, which is an NTRK inhibitor, showed a quick and durable response for 10 months. Although NTRK rearrangements are very rare in MPNST, this case highlights the importance of genetic testing in MPNST, especially using an RNA panel for the detection of rare fusion genes.

Prognostic Value of Pre-Treatment [18F]FDG PET/CT Texture Analysis in Undifferentiated Soft-Tissue Sarcoma

BACKGROUND

Undifferentiated soft-tissue sarcomas (USTS) are one of the most common sarcoma histotypes in adults. The standard of care is surgical excision plus adjuvant radiotherapy, while the use of perioperative chemotherapy is still controversial. The aim of this study was to investigate the value of pre-treatment [18F]FDG PET/CT conventional metrics and textural features in predicting disease-free survival (DFS) and overall survival (OS) in patients with USTS of the limbs and trunk.

METHODS

[18F]FDG PET/CT scans of 51 consecutive patients with locally advanced USTS were retrospectively evaluated. Conventional and textural PET parameters were analysed and tested as predictive factors for DFS and OS.

RESULTS

During a median follow up of 50.7 months, 23 (45.1%) and 29 (56.9%) patients had death or disease progression, respectively. Univariate analysis revealed a significant association for perioperative treatment, PET volumetric parameters and the textural feature GLCM_correlation with DFS and OS. In multivariate analysis, perioperative treatment and GLCM_correlation were the only independent factors, allowing stratification of the population into three different prognostic classes.

CONCLUSION

GLCM_correlation can identify USTS at high risk of relapse and death, thus helping to optimize the perioperative treatment of patients.

Comparative oncology reveals DNMT3B as a molecular vulnerability in undifferentiated pleomorphic sarcoma

PURPOSE

Undifferentiated pleomorphic sarcoma (UPS), an aggressive subtype of soft-tissue sarcoma (STS), is exceedingly rare in humans and lacks effective, well-tolerated therapies. In contrast, STS are relatively common in canine companion animals. Thus, incorporation of veterinary patients into studies of UPS offers an exciting opportunity to develop novel therapeutic strategies for this rare human disease. Genome-wide studies have demonstrated that UPS is characterized by aberrant patterns of DNA methylation. However, the mechanisms and impact of this epigenetic modification on UPS biology and clinical behavior are poorly understood.

METHODS

DNA methylation in mammalian cells is catalyzed by the canonical DNA methyltransferases DNMT1, DNMT3A and DNMT3B. Therefore, we leveraged cell lines and tissue specimens from human and canine patients, together with an orthotopic murine model, to probe the functional and clinical significance of DNMTs in UPS.

RESULTS

We found that the DNA methyltransferase DNMT3B is overexpressed in UPS relative to normal mesenchymal tissues and is associated with a poor prognosis. Consistent with these findings, genetic DNMT3B depletion strongly inhibited UPS cell proliferation and tumor progression. However, existing hypomethylating agents, including the clinically approved drug 5-aza-2'-deoxycytidine (DAC) and the DNMT3B-inhibiting tool compound nanaomycin A, were ineffective in UPS due to cellular uptake and toxicity issues.

CONCLUSIONS

DNMT3B represents a promising molecular susceptibility in UPS, but further development of DNMT3B-targeting strategies for these patients is required.

Epidemiologic Survey of Myxofibrosarcoma Using Data from the Bone and Soft Tissue Tumor Registry in Japan

BACKGROUND

Myxofibrosarcoma is a common sarcoma among older patients, with locally infiltrative behavior and a predilection for local postoperative recurrence. Some studies have reported the factors affecting prognosis, although only a few have mentioned the previous staging classification systems. This study investigated the clinical overview and prognosis of myxofibrosarcoma to determine the optimal treatment.

METHODS

This retrospective study analyzed the records of 349 patients with myxofibrosarcoma in the nationwide Bone and Soft Tissue Tumor Registry in Japan from 2006 to 2015. Clinical features, treatment options, and patient outcomes were investigated.

RESULTS

Ultimately, 349 patients were identified. The overall survival rates were 93.1% at 2 years and 84.3% at 5 years. A multivariate analysis was performed using the Cox proportional hazards model. The study identified four significant prognostic factors for survival: tumor size, depth, compartment status, and location. The prognostic score was calculated by summing the scores of all the factors. The overall survival rate was 69.3% at 5 years for the patients with prognostic scores of 6 or higher. Conversely, the patients with prognostic scores of 2 or lower had a survival rate of 95.6% at 5 years.

CONCLUSIONS

Among myxofibrosarcomas, those larger than 5 cm, deep-seated, invaded into the external compartment, or in axial body parts were associated with a significantly worse prognosis. Adjuvant radiotherapy and chemotherapy did not contribute significantly to a better prognosis. Previous staging classification systems are impractical for prognosis prediction. Therefore, new classifications are needed. Further research on new treatment methods for patients with a poor prognosis will be crucial in the future.

Metastatic undifferentiated pleomorphic sarcoma diagnosed by endoscopic ultrasound-guided fine-needle aspiration

Pathological differentiation is important for suspected lesions of metastatic undifferentiated pleomorphic sarcoma (UPS) because no reliable imaging criteria exist for this entity yet. In the present case, transgastric endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) for the pancreatic tumor and transcolonic EUS-FNA for the intraabdominal tumor contributed to the definitive diagnosis of metastatic UPS, leading to appropriate treatment selection.

Myxoid spindle cell sarcoma with ETV6-NTRK3 fusion

Myxoid spindle cell sarcoma is a rare sarcoma with a demanding histopathologic diagnosis due to the absence of pathognomic immunohistochemistry markers. Genetics include complex karyotypic alterations without characteristic molecular abnormalities for this entity. NTRK alterations are rare findings with great clinical importance since they can be therapeutically targeted with two NTRK inhibitors. Herein we present a case of an adult unclassified myxoid spindle cell sarcoma with ETV6/NTRK3 fusion gene, which is a molecular finding characteristic for infantile fibrosarcoma.

68 Ga-FAPI Versus 18 F-FDG PET/CT in Recurrent Undifferentiated Pleomorphic Sarcoma of Colon Mesentery

ABSTRACT

A 56-year-old woman presented with primary undifferentiated pleomorphic sarcoma of colon mesentery underwent complete surgical resection approximately 7 months ago. Abdominal contrast-enhanced CT showed a new mass in the descending colon, suggesting a high probability of tumor recurrence. Under a clinical trial, the patient underwent 68 Ga-FAPI and 18 F-FDG PET/CT to detect whether there are additional recurrent lesions. Compared with 18 F-FDG PET/CT, the recurrent undifferentiated pleomorphic sarcoma of colon mesentery, peritoneum, pelvic lymph node, and lung metastases showed higher uptake in 68 Ga-FAPI PET/CT. This case showed that 68 Ga-FAPI might be a promising radiopharmaceutical in the evaluation of undifferentiated pleomorphic sarcoma.

An extremely scarce incidence of primary Undifferentiated Pleomorphic Sarcoma of the Scalp of a 52-year-old female - A Case Report

Introduction and importance

Sarcomas are malignant mesenchymal-cell tumors that comprise 1 % of all adult tumors. Undifferentiated Pleomorphic Sarcoma comprises a vastly rare subtype. It mostly occurs in males in their 6th decade of life. However, their exact incidence remains poorly demarcated, especially those occurring in the scalp. Since they lack any disease-specific presentations, we should maintain high clinical suspicion when presented with similar cases.

Case presentation

Herein, we demonstrate the clinical case of a 52-year-old Middle Eastern female, who presented to the outpatient clinic complaining of a one-year history of progressively growing protuberance in her right side of the scalp. It was painful and rapidly increased in size. Presurgical radiological assessment suspected a cystic formation. Utter resection of the mass was achieved, and histopathological analysis diagnosed it as a primary Undifferentiated Pleomorphic Sarcoma.

Clinical discussion

Meticulous surgical resection was the cornerstone treatment of our patient. Radiological imaging in addition to clinical suspicion was utilized for preoperative assessment. This patient has had a successful post-surgical recovery. She has been surveilled for 6 months so far with no evidence of tumor recurrence, metastasis, or clinical complications.

Conclusion

It is especially rare to see a primary Undifferentiated Pleomorphic Sarcoma in any patient population. It's even rarer that it occurs in such a patient demographic. Hence, it's vital that we document cases of this rare malignancy because that would lead the way in conducting informative clinical studies which enable physicians to select the proper treatment modality.

•

Sarcomas are malignant mesenchymal-cell tumors that comprise 1 % of all adult tumors.

•

Undifferentiated Pleomorphic Sarcoma comprises a rare subtype. It mostly occurs in males in their 6th decade.

•

UPS showed higher tendencies to occur in males rather than females and favored the White rather than African race.

•

To establish a final diagnosis relies on competent histopathological and immunohistochemical analysis.

•

The ideal management of UPS occurring in the head and neck is utter surgical resection with free margins of 2 cm.

The immune subtypes and landscape of sarcomas

Background

Considering the molecular heterogeneity of sarcomas and their immunologically quiet character, immunotherapy (e.g., immune checkpoint inhibitors) plays a viable role in only a subset of these tumors. This study aimed to determine the immune subtypes (IMSs) of sarcomas for selecting suitable patients from an extremely heterogeneous population.

Results

By performing consensus clustering analysis of the gene expression profiles of 538 patients with sarcomas in online databases, we stratified sarcomas into three IMSs characterized by different immune cell features, tumor mutational burdens (TMBs), gene mutations, and clinical outcomes. IMS1 showed an immune “hot” and immunosuppressive phenotype, the highest frequencies of CSMD3 mutation but the lowest frequencies of HMCN1 and LAMA2 mutations; these patients had the worst progression-free survival (PFS). IMS2 was defined by a high TMB and more gene mutations, but had the lowest frequency of MND1 mutations. IMS3 displayed the highest MDN1 expression level and an immune “cold” phenotype, these patients had the worst PFS. Each subtype was associated with different expression levels of immunogenic cell death modulators and immune checkpoints. Moreover, we applied graph learning-based dimensionality reduction to the immune landscape and identified significant intra-cluster heterogeneity within each IMS. Finally, we developed and validated an immune gene signature with good prognostic performance.

Conclusions

Our results provide a conceptual framework for understanding the immunological heterogeneity of sarcomas. The identification of immune-related subtypes may facilitate optimal selection of sarcoma patients who will respond to appropriate therapeutic strategies.

Updates in Pathology for Retroperitoneal Soft Tissue Sarcoma

Retroperitoneal tumors are extremely rare. More than 70% of primary retroperitoneal soft tissue tumors are malignant. The most common sarcomas in the retroperitoneum include liposarcomas and leiomyosarcoma, however other sarcomas, along with benign mesenchymal tumors, can occur. Sarcomas are a heterogenous group of tumors with overlapping microscopic features, posing a diagnostic challenge for the pathologist. Correct tumor classification has become important for prognostication and the evolving targeted therapies for sarcoma subtypes. In this review, the pathology of retroperitoneal soft tissue sarcomas is discussed, which is important to the surgical oncologist. In addition, less common sarcomas and benign mesenchymal tumors of the retroperitoneum, which may mimic sarcoma clinically and pathologically, are also discussed.

Characterization of the immune cell infiltration landscape in myxofibrosarcoma to aid immunotherapy

Myxofibrosarcoma (MFS) is a highly malignant subtype of soft tissue sarcoma, accounting for 5% of cases. Immunotherapy guided by immune cell infiltration (ICI) is reportedly a promising treatment strategy. Here, MFS samples (n = 104) from two independent databases were classified as ICI clusters A/B/C and gene clusters A/B/C. Then, a close relationship between ICI and gene clusters was established. We found that the features of these clusters were consistent with the characteristics of immune-inflamed tumors (cluster C), immune-desert tumors (cluster B), and immune-excluded tumors (cluster A). Moreover, cluster C was sensitive to immunotherapy. Finally, an independent ICI score was established to predict the therapeutic effect, which has prospects for application in guiding immunotherapy during clinical practice.

Myxofibrosarcoma landscape: diagnostic pitfalls, clinical management and future perspectives

Myxofibrosarcoma (MFS) is a common entity of adult soft tissue sarcomas (STS) characterized by a predilection of the extremities and a high local recurrence rate. Originally classified as a myxoid variant of malignant fibrous histiocytoma, this musculoskeletal tumor has been recognized since 2002 as a distinct histotype showing a spectrum of malignant fibroblastic lesions with myxoid stroma, pleomorphism and curvilinear vessels. Currently, the molecular pathogenesis of MFS is still poorly understood and its genomic profile exhibits a complex karyotype with a number of aberrations including amplifications, deletions and loss of function. The diagnosis is challenging due to the unavailability of specific immunohistochemical markers and is based on the analysis of cytomorphologic features. The mainstay of treatment for localized disease is represented by surgical resection, with (neo)-adjuvant radio- and chemotherapy. In the metastatic setting, chemotherapy represents the backbone of treatments, however its role is still controversial and the outcome is very poor. Recent advent of genomic profiling, targeted therapies and larger enrollment of patients in translational and clinical studies, have improved the understanding of biological behavior and clinical outcome of such a disease. This review will provide an overview of current diagnostic pitfalls and clinical management of MFS. Finally, a look at future directions will be discussed.

A Case of Undifferentiated Pleomorphic Sarcoma

Suspicion for soft tissue malignancy of the hand is usually low because most tumors of the hand are small and benign. We present a case of an elderly female who presented with a rapidly enlarging, ulcerating hand mass over a few months. She was diagnosed with undifferentiated pleomorphic sarcoma (UPS), a high-grade, aggressive soft-tissue sarcoma. Computed tomography (CT) of the chest was conducted for staging purposes. It showed multiple subcentimeter pulmonary nodules, findings that were initially worrisome for metastatic disease but later proved to be newly and incidentally diagnosed granulomatous disease of the lungs. This case highlights the importance of early recognition of potential malignancy in soft-tissue tumors of the hand to facilitate proper referral and initiation of appropriate oncologic therapies. Due to early diagnosis and intervention, our patient had locally advanced disease without metastasis, a type of cancer known to have a high degree of metastatic potential.

Experimental models of undifferentiated pleomorphic sarcoma and malignant peripheral nerve sheath tumor

Undifferentiated pleomorphic sarcoma (UPS) and malignant peripheral nerve sheath tumor (MPNST) are aggressive soft tissue sarcomas that do not respond well to current treatment modalities. The limited availability of UPS and MPNST cell lines makes it challenging to identify potential therapeutic targets in a laboratory setting. Understanding the urgent need for improved treatments for these tumors and the limited cellular models available, we generated additional cell lines to study these rare cancers. Patient-derived tumors were used to establish 4 new UPS models, including one radiation-associated UPS-UPS271.1, UPS511, UPS0103, and RIS620, one unclassified spindle cell sarcoma-USC060.1, and 3 new models of MPNST-MPNST007, MPNST3813E, and MPNST4970. This study examined the utility of the new cell lines as sarcoma models by assessing their tumorigenic potential and mutation status for known sarcoma-related genes. All the cell lines formed colonies and migrated in vitro. The in vivo tumorigenic potential of the cell lines and corresponding xenografts was determined by subcutaneous injection or xenograft re-passaging into immunocompromised mice. USC060.1 and UPS511 cells formed tumors in mice upon subcutaneous injection. UPS0103 and RIS620 tumor implants formed tumors in vivo, as did MPNST007 and MPNST3813E tumor implants. Targeted sequencing analysis of a panel of genes frequently mutated in sarcomas identified TP53, RB1, and ATRX mutations in a subset of the cell lines. These new cellular models provide the scientific community with powerful tools for detailed studies of tumorigenesis and for investigating novel therapies for UPS and MPNST.

Large mirror brain metastases from primary undifferentiated sarcoma of the breast: case report and review of the literature

Primary breast sarcomas are rare high-grade tumors with a reported incidence of <1% of breast malignancies. Its dissemination to the CNS is exceptional and only one is found in the literature. The authors described the case of a 22-year-old female with history of a breast undifferentiated sarcoma that present with two large bilateral retrolenticular brain metastases. Both lesions were excised in the same procedure and she underwent adjuvant therapy. She died 24 months after surgery. Despite being aggressive lesions, aggressive treatment of primary breast sarcomas including brain metastases excision, should be considered in order to improve overall survival.

Lumbar malignant peripheral nerve sheath tumor: a rare case in a young patient

Malignant peripheral nerve sheath tumor (MPNST) is a rare soft tissue sarcoma that originate from peripheral nerves or from cells associated with the nerve sheath. We report the case of a 30‑year‑old male patient with a history of neurofibromatosis type I (NF-1) and a MPNST located in the lumbar region. The mass was resecated but surgical margins weren't clear. Recurrence of disease was observed after few months. A close monitoring of subjects with NF-1 is crucial to diagnose MPNST at an earlier stage and allow a complete surgical resection.

Malignant peripheral nerve sheath tumor: models, biology, and translation

Malignant peripheral nerve sheath tumors (MPNSTs) are aggressive, invasive cancer that comprise around 10% of all soft tissue sarcomas and develop in about 8-13% of patients with Neurofibromatosis Type 1. They are associated with poor prognosis and are the leading cause of mortality in NF1 patients. MPNSTs can also develop sporadically or following exposure to radiation. There is currently no effective targeted therapy to treat MPNSTs and surgical removal remains the mainstay treatment. Unfortunately, surgery is not always possible due to the size and location of the tumor, thus, a better understanding of MPNST initiation and development is required to design novel therapeutics. Here, we provide an overview of MPNST biology and genetics, discuss findings regarding the developmental origin of MPNST, and summarize the various model systems employed to study MPNST. Finally, we discuss current management strategies for MPNST, as well as recent developments in translating basic research findings into potential therapies.

Adult Soft-Tissue Sarcomas of the Extremities

➤

Soft-tissue sarcomas (STS) in adults comprise a heterogeneous group of tumors of mesenchymal origin that share similar biological patterns of local tumor growth and metastatic dissemination.

➤

The judicious use of imaging studies, biopsy techniques, and pathological evaluations is essential for accurate diagnosis and for planning treatment strategy.

➤

Wide local resection and radiation therapy form the cornerstone of management of high-grade STS. The role of adjuvant radiation therapy is questionable in the management of small (≤5 cm) superficial lesions that can be resected with negative margins. Chemotherapy given to patients who have nonmetastatic, high-grade STS results in varying benefit in terms of local tumor control and overall survival.

➤

Coordinated care by a multidisciplinary team of trained surgeons, medical oncologists, radiologists, radiation oncologists, and pathologists has been documented to improve local tumor control and the overall survival of patients with STS.

➤

Although considerable progress in tumor diagnostics and targeted therapies has been made over the past 2 decades, recommendations and controversies relating to tumor imaging and margins of resection have not changed.

Managing patients with advanced soft tissue sarcoma: Evolving landscape from an Australian perspective

AIM

Despite lack of advances in the first-line systemic therapy, the overall survival (OS) has continued to improve in patients with advanced soft tissue sarcoma (STS) with the recent estimation of median OS at 20 months. Several systemic therapy options are available now for the second-line and beyond, with more treatment tailored to histology and molecular subtype. The aim of this retrospective study was to characterize current patterns of care in managing patients with advanced STS (aSTS) in Australia.

METHODS

Sarcoma databases from 7 Australian sarcoma services were accessed to identify patients diagnosed with locally advanced inoperable and/or metastatic STS between January 1, 2010 and December 31, 2015. Baseline clinicopathological factors and initial treatment patterns were descriptively analyzed. For the Victorian cohort where treatment of aSTS and follow-up details were available, further exploratory analysis was conducted to determine the impact of patient and tumor characteristics and the use of palliative-intent treatment OS.

RESULTS

Of 2261 cases of STS, 671 were deemed as aSTS. Two thirds were relapsed disease with a mean 1.9 years from initial diagnosis. Median age at diagnosis of aSTS was 59 years (18-95 years) and 56.3% was male. Histology classification revealed four main subtypes: undifferentiated pleomorphic sarcoma (UPS) (23.1%), leiomyosarcoma (18.2%), liposarcoma (12.8%), synovial sarcoma (8.2%), and other comprising 14 STS subtypes. For the Victorian cohort (N = 361), approximately 80% of patients accessed palliative-intent treatment of various modalities. Nearly 40% of patients underwent tumor-debulking surgery or metastasectomy, of which lung wedge resection was the most common (N = 83, 47.7%). A total of 438 palliative-intent radiotherapy treatments were delivered to 259 patients (71.7%), with the majority in the form of external beam radiotherapy. Palliative-intent systemic therapy was delivered to 51.5% of patients (N = 186), mostly (73%). Anthracycline-based therapy was the most commonly delivered therapy (N = 135, 72.6%). Approximately half of the patients in each line of therapy failed to proceed to the subsequent line of systemic therapy with 29.4% receiving three or more lines of therapy (N = 55). A total of 18.3% of patient (N = 34) participated in clinical trials or accessed off-label drugs. The median OS for the Victoria cohort was 15.4 months (95% confidence interval: 12.1, 18.2). The UPS histology subtype was associated with poorer OS, whereas receiving any modality of palliative-intent treatment conferred survival benefit.

CONCLUSION

In Australia, aSTS is managed with diverse treatment approaches comprising various therapy modalities. Further work is planned in describing healthcare resource utilization and estimating costs by this patient cohort.

Identification of Tumor Antigens and Immune Subtypes for the Development of mRNA Vaccines and Individualized Immunotherapy in Soft Tissue Sarcoma

Soft tissue sarcomas (STS) are a rare disease with high recurrence rates and poor prognosis. Missing therapy options together with the high heterogeneity of this tumor type gives impetus to the development of individualized treatment approaches. This study identifies potential tumor antigens for the development of mRNA tumor vaccines for STS and explores potential immune subtypes, stratifying patients for immunotherapy. RNA-sequencing data and clinical information were extracted from 189 STS samples from The Cancer Genome Atlas (TCGA) and microarray data were extracted from 103 STS samples from the Gene Expression Omnibus (GEO). Potential tumor antigens were identified using cBioportal, the Oncomine database, and prognostic analyses. Consensus clustering was used to define immune subtypes and immune gene modules, and graph learning-based dimensionality reduction analysis was used to depict the immune landscape. Finally, four potential tumor antigens were identified, each related to prognosis and antigen-presenting cell infiltration in STS: HLTF, ITGA10, PLCG1, and TTC3. Six immune subtypes and six gene modules were defined and validated in an independent cohort. The different immune subtypes have different molecular, cellular, and clinical characteristics. The immune landscape of STS reveals the immunity-related distribution of patients and intra-cluster heterogeneity of immune subtypes. This study provides a theoretical framework for STS mRNA vaccine development and the selection of patients for vaccination, and provides a reference for promoting individualized immunotherapy.

Multimodality treatment of undifferentiated pleomorphic soft tissue sarcoma of the extremity (eUPS) in the elderly

INTRODUCTION

This subgroup analysis of undifferentiated pleomorphic soft tissue sarcoma of the extremity (eUPS) from the PERSARC collaborative group aimed to achieve a more personalized multimodality treatment approach for primary eUPS in elderly patients.

MATERIAL AND METHODS

A multicenter retrospective study including primary high-grade eUPS surgically treated with curative intent between 2000 and 2016. Overall survival (OS), local recurrence (LR) and distant metastasis (DM) curves were calculated by Kaplan Meier analysis. Cox proportional hazard models were used to determine the effect of radiotherapy.

RESULTS

From a total of 2511 patients with extremity soft tissue sarcoma (eSTS) of the PERSARC study collaborative; 703 patients with eUPS were included in this study. In elderly patients with eUPS 5-year OS, LR and DM were 35.4 (95%CI 29.3-42.8), 17.7 (95%CI 12.7-22.6) and 24.6 (95%CI 19.1-30.1). eUPS was significantly less treated with radiotherapy compared with other eSTS, especially in elderly patients. Patients with R1-R2 margins treated with radiotherapy had about half the risk of developing LR compared with patients treated without radiotherapy (HR = 0.454, p = 0.033).

CONCLUSION

Elderly patients with eUPS were less often treated with radiotherapy and showed higher LR. Nowadays, given an increasing life expectancy in elderly patients, multimodality treatment should be considered.

A Novel Four-Gene Prognostic Signature for Prediction of Survival in Patients with Soft Tissue Sarcoma

Simple Summary

Soft tissue sarcomas (STS) still lack effective clinical stratification and prognostic models. The aim of this study is to establish a reliable prognostic gene signature in STS. Using 189 STS samples from the TCGA database, a four-gene signature (including DHRS3, JRK, TARDBP and TTC3) and nomograms that can be used to predict the overall survival and relapse free survival of STS patients was developed. The predictive ability for metastasis free survival was externally verified in the GEO cohort. We demonstrated that the novel gene signature provides an attractive platform for risk stratification and prognosis prediction of STS patients, which is of great importance for individualized clinical treatment and long-term management of patients with this rare and severe disease.

Abstract

Soft tissue sarcomas (STS), a group of rare malignant tumours with high tissue heterogeneity, still lack effective clinical stratification and prognostic models. Therefore, we conducted this study to establish a reliable prognostic gene signature. Using 189 STS patients’ data from The Cancer Genome Atlas database, a four-gene signature including DHRS3, JRK, TARDBP and TTC3 was established. A risk score based on this gene signature was able to divide STS patients into a low-risk and a high-risk group. The latter had significantly worse overall survival (OS) and relapse free survival (RFS), and Cox regression analyses showed that the risk score is an independent prognostic factor. Nomograms containing the four-gene signature have also been established and have been verified through calibration curves. In addition, the predictive ability of this four-gene signature for STS metastasis free survival was verified in an independent cohort (309 STS patients from the Gene Expression Omnibus database). Finally, Gene Set Enrichment Analysis indicated that the four-gene signature may be related to some pathways associated with tumorigenesis, growth, and metastasis. In conclusion, our study establishes a novel four-gene signature and clinically feasible nomograms to predict the OS and RFS. This can help personalized treatment decisions, long-term patient management, and possible future development of targeted therapy.

Establishment and characterization of NCC-UPS3-C1: a novel patient-derived cell line of undifferentiated pleomorphic sarcoma

Undifferentiated pleomorphic sarcoma (UPS), previously termed malignant fibrous histiocytoma, is one of the most aggressive sarcomas with no identifiable line of differentiation. Although the molecular mechanism of oncogenesis in UPS has not been clarified, radiation exposure is considered to be a risk factor in the development of UPS. In the treatment of UPS, surgical treatment remains the most important modality. While chemotherapy is considered in unresectable or metastatic cases, UPS is known to be refractory to conventional chemotherapy, leading to an unfavorable prognosis. To improve the clinical outcome of this condition, novel treatment methods are urgently needed. Patient-derived cell lines are essential tools in preclinical studies. However, owing to the rarity of UPS, only four UPS cell lines are publicly available. Thus, we established a novel UPS cell line, NCC-UPS3-C1, using a surgically resected tumor from a patient with radiation-associated UPS. NCC-UPS3-C1 cells had multiple genomic deletions including the tumor suppressor genes CDKN2A and CDKN2B. NCC-UPS3-C1 cells demonstrated constant growth, spheroid formation, and aggressive invasion ability. We also conducted a screening test using 214 drugs and identified that the histone deacetylase inhibitor, romidepsin, is highly effective on NCC-UPS3-C1 cells. Thus, we concluded that the NCC-UPS3-C1 cell line is a useful tool in preclinical studies for UPS.

Low-Grade Fibromyxoid Sarcoma of the Back

A 29-year-old male presented with a seven-year history of a slow-growing, painless, firm, mobile mass in the right upper back that was bothersome when supine or with direct pressure. On initial presentation, a clinical diagnosis of lipoma was given. The mass progressively increased in size over several years but remained painless. The mass measured 15 x 10 cm on examination. Excision of the lesion was performed, which revealed a white cut surface with cystic degenerative changes. Histologically, the lesion revealed spindle cell morphology with occasional mitosis. Diffuse immunohistochemical staining with MUC4 supports a diagnosis of low-grade fibromyxoid sarcoma (LGFMS). Tumor was present with focal extension into the deep margin. However, serial magnetic resonance imaging studies performed suggest no residual disease and negative regional lymph node involvement. This case demonstrates the growth pattern of LGFMS, but also denotes the importance of correlating radiological and pathological features to accurately diagnose and treat these tumors in a timely fashion.

Malignant fibrous histiocytoma of the bone in a traumatic amputation stump: A case report and review of the literature

BACKGROUND

Malignant fibrous histiocytoma (MFH) is one of the most common soft tissue sarcomas among adults. It is characterized by large size, high grade, and biological aggressiveness. There are many reports of MFH after local stimulation, such as bone fracture, implants, and chronic osteomyelitis. In this paper, we report a patient who developed MFH 6 years after amputation, suggesting that wound healing and mechanical force play a role in the local stimulation of this disease.

CASE SUMMARY

A 66-year-old man complained of persistent pain in his residual mid-thigh. He had undergone amputation surgery due to a traffic accident 6 years prior. Physical examination showed tenderness but no abnormalities in appearance. X-ray radiographs and magnetic resonance imaging supported the diagnosis of a tumor, and a biopsy confirmed that the lesion was MFH. The patient received neoadjuvant chemotherapy and left hip disarticulation. During the 6-mo follow-up, there were no symptoms of recurrence.

CONCLUSION

Postsurgery MFH has been reported before, and many studies have attributed it to the biological effects of implants. Our case report shows that this disease can develop without an implant and thus highlights the importance of local stimulation. The wound-healing process and mechanical force can both promote this tumor, but whether they directly cause MFH needs further investigation.

The Paradoxical Role of Cellular Senescence in Cancer

Cellular senescence occurs in proliferating cells as a consequence of various triggers including telomere shortening, DNA damage, and inappropriate expression of oncogenes. The senescent state is accompanied by failure to reenter the cell cycle under mitotic stimulation, resistance to cell death and enhanced secretory phenotype. A growing number of studies have convincingly demonstrated a paradoxical role for spontaneous senescence and therapy-induced senescence (TIS), that senescence may involve both cancer prevention and cancer aggressiveness. Cellular senescence was initially described as a physiological suppressor mechanism of tumor cells, because cancer development requires cell proliferation. However, there is growing evidence that senescent cells may contribute to oncogenesis, partly in a senescence-associated secretory phenotype (SASP)-dependent manner. On the one hand, SASP prevents cell division and promotes immune clearance of damaged cells, thereby avoiding tumor development. On the other hand, SASP contributes to tumor progression and relapse through creating an immunosuppressive environment. In this review, we performed a review to summarize both bright and dark sides of senescence in cancer, and the strategies to handle senescence in cancer therapy were also discussed.