Managing sarcoma: where have we come from and where are we going?

Beyond the benign: A rare case report of myxoid pleomorphic liposarcoma

Myxoid pleomorphic liposarcoma is a rare and aggressive subtype of soft tissue sarcomas (STS). It primarily arises from adipose tissue and exhibits a high rate of recurrence and metastatic potential. We report the case of a 35-year-old male gym trainer with a 5-month history of a painless, progressively enlarging mass on the right posterior aspect of chest, diagnosed with myxoid pleomorphic liposarcoma following imaging and histopathological evaluation of the excised specimen. Surgical excision with clear margins and adjuvant radiotherapy resulted in a favorable outcome with no recurrence at 7 months. This case emphasizes the importance of early diagnosis and multidisciplinary approach in managing a rare soft tissue sarcoma to prevent complications from a delayed intervention.

[Practical Guidance on the Detection of NTRK Fusions in Sarcomas: Current Status and Diagnostic Challenges]

Sarcomas are a rare and heterogeneous group of mesenchymal malignant tumors and account for approximately 1% of all adult cancers and around 20% of all pediatric solid tumors in Europe. Technology advances have enabled a more accurate and efficient characterization of the molecular mechanisms underlying the pathogenesis of sarcoma subtypes and revealed novel and unexpected therapeutic targets with prognostic/predictive biomarkers, namely the neurotrophic tyrosine receptor kinase (NTRK) gene fusion. The NTRK fusion assessment has recently become a standard part of management for patients with unresectable locally advanced or metastatic cancers and has been identified in various tumor types. In the more prevalent adult and pediatric sarcomas, NTRK fusions are present in 1% and 20%, respectively, and in more than 90% of very rare subsets of tumors. The inhibition of TRK activity with first-generation TRK inhibitors has been found to be effective and well tolerated in adult and pediatric patients, independently of the tumor type. Overall, the therapeutic benefit to those patients compensates for the difficulties of identifying NTRK gene fusions. However, the rarity and diagnostic complexity of NTRK gene fusions raise several questions and challenges for clinicians. To address these issues, an expert panel of medical and pediatric oncologists, radiologists, surgeons, orthopedists, and pathologists reviewed the recent literature and discussed the current status and challenges, proposing a diagnostic algorithm for identifying NTRK fusion sarcomas. The aim of this article is to review the updated information on this issue and to provide the experts' recommendations and practical guidance on the optimal management of patients with soft tissue sarcomas, infantile fibrosarcoma, gastrointestinal stromal tumors, and osteosarcoma.

Exploring CX3CR1 as a prognostic biomarker and immunotherapeutic target in sarcoma

BACKGROUND

Sarcomas (SARC) are a diverse group of malignant tumors originating from mesenchymal tissues, characterized by poor prognosis under conventional therapies. CX3CR1, a chemokine receptor involved in immune cell migration, has emerged as a key player in SARC. Post-translational modifications (PTMs) such as phosphorylation and ubiquitination critically modulate CX3CR1, influencing cancer progression, immune responses, and treatment resistance.

METHODS

This study investigates CX3CR1 expression, its biological functions, and prognostic value in SARC. Using data from The Cancer Genome Atlas (TCGA), we analyzed CX3CR1 gene expression, methylation patterns, CRISPR screening results, and immune infiltration metrics. Functional experiments included knockout and overexpression models, CCK-8 assays and flow cytometry to assess apoptosis.

RESULTS

CX3CR1 expression was significantly elevated in SARC tissues and positively correlated with overall survival, disease-specific survival, and progression-free intervals. Methylation analysis identified CpG sites associated with CX3CR1 expression, differentiating tumor and adjacent tissues. CRISPR screening highlighted CX3CR1's essential role in tumor growth, while immune infiltration analysis underscored its impact on the tumor microenvironment. PTMs were found to stabilize CX3CR1, enhancing its activity in key signaling pathways. Overexpression of CX3CR1 amplified inflammatory and apoptotic responses, while knockdown showed protective effects in vitro.

CONCLUSIONS

CX3CR1 serves as a promising prognostic biomarker and therapeutic target in sarcoma. Targeting CX3CR1's PTMs could advance personalized treatments and improve outcomes for sarcoma patients.

A Retrospective Study of 291 Patients With Head and Neck Sarcomas: Treatment, Outcomes, and Prognostic Factors

AIMS

Sarcomas constitute a group of rare malignant neoplasms, commonly subcategorized into soft tissue sarcomas (STS) and bone sarcomas. This study aims to describe the treatment modalities and outcome of head and neck sarcoma (HNS) patients in western Denmark and to identify prognostic factors for overall survival and recurrence in HNS patients.

MATERIALS AND METHODS

The Aarhus sarcoma registry, The National Danish Sarcoma Database, and the Danish National Pathology Registry were used to identify HNS adult patients diagnosed between 1979 and 2022.

RESULTS

Altogether, 291 patients were included in this study. The prevalent histological subtypes were undifferentiated pleomorphic sarcoma (16%; 48/291) and leiomyosarcoma (15%; 44/291) for STS patients (n = 230) and chondrosarcoma (10%; 28/291) and osteosarcoma (7%; 19/291) for bone sarcoma patients (n = 61). Surgery with curative intent was performed in 71% (164/230) and 70% (43/61) of STS and bone sarcoma patients, respectively. Clear resection was achieved in 59% (97/164) of STS patients and 44% (19/43) of bone sarcoma patients. Eighty-nine patients relapsed (STS n = 66, bone sarcoma n = 23) after a median time of 2.7/5.5 years for STS/bone sarcoma patients. The five-year overall survival rates were 45% for STS patients and 66% for bone sarcoma patients. The following factors were significantly, negatively associated with overall survival in STS patients: Age (hazard ratio (HR)) = 1.02, p < 0.001), tumour size ≥5 cm (HR = 1.75, p = 0.003), metastatic disease (HR = 3.17, p < 0.001), high grade tumour (HR = 2.24, p = 0.004), previous cancer (HR = 2.84, p < 0.001), and high Aarhus composite biomarker score (ACBS) (HR = 4.56, p = 0.001). For relapse in STS patients, higher tumour grade (HR = 3.19, p = 0.014), intralesional margins (HR = 2.84, p < 0.001), ≥2 previous cancers (HR = 3.00, p = 0.004), and high ACBS (HR = 3.29, p = 0.047), were negatively associated. For bone sarcomas only higher age (HR = 1.02, p = 0.049) and intralesional margins (HR = 2.91, p = 0.042) were significant negative factors for overall survival.

CONCLUSION

Multiple prognostic factors for overall survival and relapse were identified, especially for STS patients.

Studies on Autophagy and Apoptosis of Fibrosarcoma HT-1080 Cells Mediated by Chalcone with Indole Moiety

This study demonstrated the anticancer efficacy of chalcones with indole moiety (MIPP, MOMIPP) in fibrosarcoma cells for the first time. The results showed that MIPP and MOMIPP reduced the viability of HT-1080 cells in a concentration-dependent manner. MOMIPP was more active than MIPP in HT-1080 cells, showing lower IC50 values (3.67 vs. 29.90 μM). Both compounds at a concentration of 1 μM induced apoptosis in HT-1080 cells, causing death strictly related to caspase activation, as cell viability was restored when the caspase inhibitor Z-VAD was added. Reactive oxygen species production was approximately 3-fold higher than in control cells, and cotreatment with the inhibitor of mitochondrial ATPase oligomycin diminished this effect. Such effects were also reflected in mitochondrial dysfunction, including decreased membrane potential. Interestingly, the compounds that were studied caused massive vacuolization in HT-1080 cells. Immunocytochemical staining and TEM analysis showed that HT-1080 cells exhibited increased expression of the LC3-II protein and the presence of autophagosomes with a double membrane, respectively. Both compounds induced apoptosis, highlighting a promising link between autophagy and apoptosis. This connection could be a new target for therapeutic strategies to overcome chemoresistance, which is a significant cause of treatment failure and tumour recurrence in fibrosarcoma following traditional chemotherapy.

68 Ga-Pentixafor PET/CT for in-vivo mapping of CXCR4 receptors as potential radiotheranostic targets in soft tissue and bone sarcoma: preliminary results

OBJECTIVE

To evaluate the diagnostic utility of 68 Ga-Pentixafor PET/CT for in vivo imaging of CXCR4 receptors in soft tissue/bone sarcoma.

METHODS

Ten (7M: 3F; mean age = 24.7 ± 14.2 years) consecutive patients with clinical and radiological evidence of bone/soft tissue sarcoma were recruited prospectively whole body 68 Ga-Pentixafor PET/CT imaging was performed at 60-min after tracer administration. After performing standard CT, PET acquisition from head to toe was done (3 min/bed position) in a caudocranial direction. PET/CT data was reconstructed and SUV max , SUV mean values, target-to-background ratio (TBR) and active tumor volume (cc) were computed for the tracer avid lesions. Histopathological and IHC analysis was performed on the surgically excised primary tumors. CXCR4 receptors' intensity was evaluated by visual scoring.

RESULTS

The mean SUV max and SUV mean values in the primary tumors were 4.80 ± 1.0 (3.9-7.7) and 2.40 ± 0.60 (0.9-4.0). The mean TBR and tumor volume (cc) were 1.84 ± 1.3 and 312.2 ± 285. Diagnosis of osteosarcoma in 7, chondrosarcoma, leiomyosarcoma and synovial sarcoma in 1 patient each was confirmed on HP analysis. Distant metastatic lesions were seen in 3/10 patients. Nuclear CXCR4 receptors' positivity was seen in 5, cytoplasmic in 4 and both pattern seen in 1 patient. The mean CXCR4 receptors' intensity was found to be 7.6 ± 2. The highest SUV max value of 7.7 was observed in the patient having both cytoplasmic and nuclear CXCR4 expression. SUV max was found to be poorly correlated ( r  = 0.441) with CXCR4 expression.

CONCLUSION

68 Ga-Pentixafor PET/CT detects CXCR4 receptors over-expressed in sarcoma, its radio-theranostics potential needs detailed evaluation.

A study protocol for an open-label, single-arm, single-center phase I clinical study on tolerability, safety, and efficacy of dalpiciclib combined with apatinib in the treatment of patients with advanced or metastatic sarcoma

INTRODUCTION

The prognosis of patients with advanced or metastatic sarcoma is very poor, and a new strategy for patients who fail systemic treatment is urgently required. Apatinib is a small molecule tyrosine kinase inhibitor of VEGFR-2, which can exert an antitumor effect by blocking downstream PI3K/AKT and VEGFR2/STAT3 signaling pathways of sarcoma. Dysregulation of the cyclin D (CCND)-cyclin-dependent kinase 4/6 (CDK4/6)-retinoblastoma 1 (Rb) pathway is highly prevalent in sarcoma. Thus, blocking VEGFR2 and CDK4/6 may exert a synergistic effect. We hypothesize that a combination of apatinib and dalpiciclib, an oral, highly effective, and selective small molecule CDK4/6 inhibitor, may result in higher antitumor efficacy in patients with refractory sarcoma.

METHODS

In this open-label, single-arm, single-center phase I trial, participants diagnosed with sarcoma who failed standard systemic treatment will be enrolled. Dose escalation will be conducted into three groups according to traditional 3 + 3 principle: dose 1, dalpiciclib 100 mg once daily oral d1-21+ apatinib 250 mg once daily oral d1-28, every 28 days as one cycle; dose 2, dalpiciclib 100 mg d1-21+ apatinib 500 mg d1-28; dose 3, dalpiciclib 150 mg d-21+ apatinib 500 mg d1-28. The primary endpoint is the safety and tolerability of combined treatment. The secondary endpoint is to evaluate the initial efficacy, including objective response rate (ORR), disease control rate (DCR), duration of response (DoR), and progression-free survival (PFS).

DISCUSSION

This trial will provide evidence of the tolerability, safety, and efficacy of dalpiciclib in combination with apatinib in metastatic sarcoma patients who have failed first-line systemic treatment.

Identification of an ADME-related gene for forecasting the prognosis and responding to immunotherapy in sarcomas

There are more than 170 subtypes of sarcomas (SARC), which pose a challenge for diagnosis and patient management. Relatively simple or complex karyotypes play an indispensable role in the early diagnosis and effective treatment of SARC. The genes related to absorption, distribution, metabolism, and excretion (ADME) of a drug can serve as prognostic biomarkers of cancer and potential drug targets. In this study, a risk score signature was created. The SARC cohort was downloaded from The Cancer Genome Atlas (TCGA) database, and divided into high-risk group and low-risk group according to the median value of risk score. Compared with high-risk group, low-risk group has a longer survival time, which is also verified in osteosarcoma cohort from Therapeutically Applicable Research to Generate Effective Treatments (TARGET) database. In addition, the relationship between the signature and immunophenotypes, including status of immune cell infiltration and immune checkpoint expression, was explored. Then, we found that high-risk group is in immunosuppressive status. Finally, we verified that PPARD played a role as a carcinogen in osteosarcoma, which provided a direction for targeted treatment of osteosarcoma in the future. Generally speaking, the signature can not only help clinicians predict the prognosis of patients with SARC, but also provide a theoretical basis for developing more effective targeted drugs in the future.

Identification of therapeutic targets and prognostic biomarkers in the Siglec family of genes in tumor immune microenvironment of sarcoma

Sarcomas (SARC) are a highly heterogeneous cancer type that is prone to recurrence and metastasis. Numerous studies have confirmed that Siglecs are involved in immune signaling and play a key role in regulating immune responses in inflammatory diseases and various cancers. However, studies that systematically explore the therapeutic and prognostic value of Siglecs in SARC patients are very limited. The online databases GEPIA, UALCAN, TIMER, The Kaplan-Meier Plotter, GeneMANIA, cBioPortal, and STING were used in this study. IHC staining was performed on the collected patient tissues, and clinical data were statistically analyzed. The transcript levels of most Siglec family members showed a high expression pattern in SARC. Compared with normal tissues, Siglec-5, Siglec-10, and Siglec-12 were abnormally highly expressed in tumor tissues. Importantly, Siglec-15 was significantly associated with poor prognosis. Functional enrichment analysis showed that the Siglec family was mainly enriched in hematopoietic cell lineages. The genes associated with molecular mutations in the Siglec family were mainly TP53 and MUC16, among which Siglec-2 and Siglec-15 were significantly associated with the survival of patients. The expression levels of all Siglec family members were significantly correlated with various types of immune cells (B cells, CD8 + T cells, CD4 + T cells, macrophages, neutrophils and dendritic cells). Furthermore, a significant correlation was found between the somatic copy number changes of all Siglec molecules and the abundance of immune infiltrates. Our study paints a promising vision for the development of immunotherapy drugs and the construction of prognostic stratification models by investigating the therapeutic and prognostic potential of the Siglec family for SARC.

Preclinical Models of Visceral Sarcomas

Visceral sarcomas are a rare malignant subgroup of soft tissue sarcomas (STSs). STSs, accounting for 1% of all adult tumors, are derived from mesenchymal tissues and exhibit a wide heterogeneity. Their rarity and the high number of histotypes hinder the understanding of tumor development mechanisms and negatively influence clinical outcomes and treatment approaches. Although some STSs (~20%) have identifiable genetic markers, as specific mutations or translocations, most are characterized by complex genomic profiles. Thus, identification of new therapeutic targets and development of personalized therapies are urgent clinical needs. Although cell lines are useful for preclinical investigations, more reliable preclinical models are required to develop and test new potential therapies. Here, we provide an overview of the available in vitro and in vivo models of visceral sarcomas, whose gene signatures are still not well characterized, to highlight current challenges and provide insights for future studies.

Chemotherapeutic drugs for soft tissue sarcomas: a review

Despite the low incidence of soft tissue sarcomas (STSs), hundreds of thousands of new STS cases are diagnosed annually worldwide, and approximately half of them eventually progress to advanced stages. Currently, chemotherapy is the first-line treatment for advanced STSs. There are difficulties in selecting appropriate drugs for multiline chemotherapy, or for combination treatment of different STS histological subtypes. In this study, we first comprehensively reviewed the efficacy of various chemotherapeutic drugs in the treatment of STSs, and then described the current status of sensitive drugs for different STS subtypes. anthracyclines are the most important systemic treatment for advanced STSs. Ifosfamide, trabectedin, gemcitabine, taxanes, dacarbazine, and eribulin exhibit certain activities in STSs. Vinca alkaloid agents (vindesine, vinblastine, vinorelbine, vincristine) have important therapeutic effects in specific STS subtypes, such as rhabdomyosarcoma and Ewing sarcoma family tumors, whereas their activity in other subtypes is weak. Other chemotherapeutic drugs (methotrexate, cisplatin, etoposide, pemetrexed) have weak efficacy in STSs and are rarely used. It is necessary to select specific second- or above-line chemotherapeutic drugs depending on the histological subtype. This review aims to provide a reference for the selection of chemotherapeutic drugs for multi-line therapy for patients with advanced STSs who have an increasingly long survival.

Imaging Hallmarks of Sarcoma Progression Via X-ray Computed Tomography: Beholding the Flower of Evil

Simple Summary

Sarcomas represent the largest group of rare solid tumors that arise from mesenchymal stem cells and are a leading cause of cancer death in individuals younger than 20 years of age. There is an immediate need for the development of an algorithm for the early accurate diagnosis of sarcomas due to the high rate of diagnostic inaccuracy, which reaches up to 30%. X-ray computed tomography is a non-invasive imaging technique used to obtain detailed internal images of the human or animal body in clinical practice and preclinical studies. We summarized the main imaging features of soft tissue and bone sarcomas, and noted the development of new molecular markers to reach tumor type-specific imaging. Also, we demonstrated the possibility of the use X-ray computed microtomography for non-destructive 3D visualization of sarcoma progression in preclinical studies. Finding correlations between X-ray computed tomography modalities and the results of the histopathological specimen examination may significantly increase the accuracy of diagnostics, which leads to the initiation of appropriate management in a timely manner and, consequently, to improved outcomes.

Abstract

Sarcomas are a leading cause of cancer death in individuals younger than 20 years of age and represent the largest group of rare solid tumors. To date, more than 100 morphological subtypes of sarcomas have been described, among which epidemiology, clinical features, management, and prognosis differ significantly. Delays and errors in the diagnosis of sarcomas limit the number of effective therapeutic modalities and catastrophically worsen the prognosis. Therefore, the development of an algorithm for the early accurate diagnosis of sarcomas seems to be as important as the development of novel therapeutic advances. This literature review aims to summarize the results of recent investigations regarding the imaging of sarcoma progression based on the use of X-ray computed tomography (CT) in preclinical studies and in current clinical practice through the lens of cancer hallmarks. We attempted to summarize the main CT imaging features of soft-tissue and bone sarcomas. We noted the development of new molecular markers with high specificity to antibodies and chemokines, which are expressed in particular sarcoma subtypes to reach tumor type-specific imaging. We demonstrate the possibility of the use of X-ray computed microtomography (micro-CT) for non-destructive 3D visualization of solid tumors by increasing the visibility of soft tissues with X-ray scattering agents. Based on the results of recent studies, we hypothesize that micro-CT enables the visualization of neovascularization and stroma formation in sarcomas at high-resolution in vivo and ex vivo, including the novel techniques of whole-block and whole-tissue imaging. Finding correlations between CT, PET/CT, and micro-CT imaging features, the results of the histopathological specimen examination and clinical outcomes may significantly increase the accuracy of soft-tissue and bone tumor diagnostics, which leads to the initiation of appropriate histotype-specific management in a timely manner and, consequently, to improved outcomes.

Heparanase 2 (Hpa2) attenuates the growth of human sarcoma

The pro-tumorigenic properties of heparanase are well documented and established. In contrast, the role of heparanase 2 (Hpa2), a close homolog of heparanase, in cancer is not entirely clear. In carcinomas, Hpa2 is thought to attenuate tumor growth, possibly by inhibiting heparanase enzymatic activity. Here, we examine the role of Hpa2 in sarcoma, a group of rare tumors of mesenchymal origin, accounting for approximately 1% of all malignant tumors. Consistently, we found that overexpression of Hpa2 attenuates tumor growth while Hpa2 gene silencing results in bigger tumors. Mechanistically, attenuation of tumor growth by Hpa2 was associated with increased tumor stress conditions, involving ER stress, hypoxia, and JNK phosphorylation, leading to increased apoptotic cell death. In addition, overexpression of Hpa2 induces the expression of the p53 family member, p63 which, in sarcoma, functions to attenuate tumor growth. Moreover, we show that Hpa2 profoundly reduces stem cell characteristics of the sarcoma cells (stemness), most evident by failure of Hpa2 cells to grow as spheroids typical of stem cells. Likewise, expression of CD44, a well-established stem cell marker, was prominently decreased in Hpa2 cells. CD44 is also a cell surface receptor for hyaluronic acid (HA), a nonsulfated glycosaminoglycan that is enriched in connective tissues. Reduced expression of CD44 by Hpa2 may thus represent impaired cross-talk between Hpa2 and the extracellular matrix. Clinically, we found that Hpa2 is expressed by leiomyosarcoma tumor biopsies. Interestingly, nuclear localization of Hpa2 was associated with low-stage tumors. This finding opens a new direction in Hpa2 research.

Comprehensive analysis of GINS subunits prognostic value and ceRNA network in sarcoma

Background: The GINS complex, composed of GINS1/2/3/4 subunits, is an essential structure of Cdc45-MCM-GINS (CMG) helicase and plays a vital role in establishing the DNA replication fork and chromosome replication. Meanwhile, GINS genes have been associated with the poor prognosis of various malignancies. However, the abnormal expression of GINS genes and their diagnostic and prognostic value in sarcomas (SARC) remain unclear.

Methods: Oncomine, Gene Expression Profiling Interactive Analysis (GEPIA), Kaplan-Meier Plotter, Cancer cell line encyclopedia (CCLE), The University of Alabama at Birmingham Cancer Data Analysis Portal (UALCAN), R studio, and Tumor Immune Estimation Resource (TIMER) were used to analyze the expression profiles, prognostic value, biological function, ceRNA, and immune infiltration associated with GINS genes in sarcomas.

Results: We found that GINS1/2/3/4 genes exhibited significantly upregulated transcription levels in SARC samples compared to non-tumor tissues and exhibited high expression levels in sarcoma cell lines. In addition, SARC patients with increased expression levels of GINS1/2/3/4 showed poorer survival rates. Immune infiltration analysis showed that GINS subunits were closely associated with the infiltration of immune cells in sarcomas.

Conclusion: Our research identified GINS subunits as potential diagnostic and prognostic biological targets in SARC and elucidated their underlying effects in the genesis and progression of SARC. These results may provide new opportunities and research directions for targeted sarcoma therapy.

Clinical outcomes of brain metastasectomy from soft tissue and bone sarcomas: a systematic review

BACKGROUND

Brain metastasis in sarcomas is associated with a poor prognosis. Data regarding prognostic factors and clinical outcomes of surgical resection of brain metastasis from sarcomas are limited. The objective of this systematic review was to evaluate survival outcomes post-brain metastasectomy for patients with soft tissue and bone sarcomas.

METHODS

A systematic review was conducted examining survival outcomes among adults and children with soft tissue and bone sarcoma undergoing brain metastasectomy, in the English language from inception up to May 31, 2021. Two reviewers independently evaluated and screened the literature, extracted the data, and graded the included studies. The body of evidence was evaluated and graded according to the Newcastle-Ottawa Quality Assessment Scale for Cohort Studies and the Joanna Briggs Institute Critical Appraisal Checklist for Case Series. Results were synthesized using descriptive methods. A meta-analysis was not possible due to the low quality and heterogeneity of studies.

RESULTS

Ten studies published between 1994 and 2020 were included: three were retrospective cohort studies and seven were case series. 507 patients were included, of whom 269 underwent brain metastasectomy. The median follow-up period ranged between 14 and 29 months. The median survival period after metastasectomy ranged from 7 to 25 months. The most common prognostic factors associated with survival included presenting performance status, age, number of brain metastases, presence of lung metastases, and peri-operative radiation therapy administration.

DISCUSSION

Although the level of evidence is low, retrospective studies support that brain metastasectomy can be performed with reasonable post-operative survival in selected individuals.

The Role of CDK Pathway Dysregulation and Its Therapeutic Potential in Soft Tissue Sarcoma

Soft tissue sarcomas (STSs) are tumors that are challenging to treat due to their pathologic and molecular heterogeneity and their tumor biology that is not yet fully understood. Recent research indicates that dysregulation of cyclin-dependent kinase (CDK) signaling pathways can be a strong driver of sarcogenesis. CDKs are enzyme forms that play a crucial role in cell-cycle control and transcription. They belong to the protein kinases group and to the serine/threonine kinases subgroup. Recently identified CDK/cyclin complexes and established CDK/cyclin complexes that regulate the cell cycle are involved in the regulation of gene expression through phosphorylation of critical components of transcription and pre-mRNA processing mechanisms. The current and continually growing body of data shows that CDKs play a decisive role in tumor development and are involved in the proliferation and growth of sarcoma cells. Since the abnormal expression or activation of large numbers of CDKs is considered to be characteristic of cancer development and progression, dysregulation of the CDK signaling pathways occurs in many subtypes of STSs. This review discusses how reversal and regulation can be achieved with new therapeutics and summarizes the current evidence from studies regarding CDK modulation for STS treatment.

A Pulmonary Zebra: Adult Primary Pulmonary Synovial Sarcoma

Primary pulmonary synovial sarcoma (PPSS) is an extremely rare tumor, with approximately 50 cases being reported in the English literature (Golota et al., 2018). Difficulties are often encountered in the diagnosis of PPSS as it can be confused with other spindle or round cell tumors, such as fibrosarcoma, hemangiopericytoma, mesothelioma, sarcomatoid carcinoma, or metastatic sarcomas. PPSS was first described by Zeren et al. in 1995. We present a case of PPSS in a 41-year-old woman, who complained of progressive dyspnea and left-sided chest pain.

Clinical Utility of CDK4/6 Inhibitors in Sarcoma: Successes and Future Challenges

PURPOSE

Soft tissue and bone sarcomas are rare malignancies that exhibit significant pathologic and molecular heterogeneity. Deregulation of the CDKN2A-CCND-CDK4/6-retinoblastoma 1 (Rb) pathway is frequently observed in about 25% of unselected sarcomas and is pathognomonic for specific sarcoma subtypes. This genomic specificity has fueled the clinical evaluation of selective CDK4/6 inhibitors in sarcomas. Here, we highlight successes, opportunities, and future challenges for using CDK4/6 inhibitors to treat sarcoma.

MATERIALS AND METHODS

This review summarizes the current evidence for the use of CDK4/6 inhibitors in sarcoma while identifying molecular rationale and predictive biomarkers that provide the foundation for targeting the CDK4/6 pathway in sarcoma. A systematic review was performed of articles indexed in the PubMed database and the National Institutes of Health Clinical Trials Registry (ClinicalTrials.gov). For each sarcoma subtype, we discuss the preclinical rationale, case reports, and available clinical trials data.

RESULTS

Despite promising clinical outcomes in a subset of sarcomas, resistance to CDK4/6 inhibitors results in highly heterogeneous clinical outcomes. Current clinical data support the use of CDK4/6 inhibitors in subsets of sarcoma primarily driven by CDK4/6 deregulation. When dysregulation of the Rb pathway is a secondary driver of sarcoma, combination therapy with CDK4/6 inhibition may be an option. Developing strategies to identify responders and the mechanisms that drive resistance is important to maximize the clinical utility of these drugs in patients with sarcoma. Potential biomarkers that indicate CDK4/6 inhibitor sensitivity in sarcoma include CDK4, CCND, CCNE, RB1, E2F1, and CDKN2A.

CONCLUSION

CDK4/6 inhibitors represent a major breakthrough for targeted cancer treatment. CDK4/6 inhibitor use in sarcoma has led to limited, but significant, early clinical success. Targeted future clinical research will be key to unlocking the potential of CDK4/6 inhibition in sarcoma.

Targeting the oncogenic TBX3:nucleolin complex to treat multiple sarcoma subtypes

Sarcomas are diverse cancers of mesenchymal origin, with compromised clinical management caused by insufficient diagnostic biomarkers and limited treatment options. The transcription factor TBX3 is upregulated in a diverse range of sarcoma subtypes, where it plays a direct oncogenic role, and it may thus represent a novel therapeutic target. To identify versatile ways to target TBX3, we performed affinity purification coupled by mass spectrometry to identify putative TBX3 protein cofactors that regulate its oncogenic activity in sarcomas. Here we identify and validate the multifunctional phosphoprotein nucleolin as a TBX3 cofactor. We show that nucleolin is co-expressed with TBX3 in several sarcoma subtypes and their expression levels positively correlate in sarcoma patients which are associated with poor prognosis. Furthermore, we demonstrate that nucleolin and TBX3 interact in chondrosarcoma, liposarcoma and rhabdomyosarcoma cells where they act together to enhance proliferation and migration and regulate a common set of tumor suppressor genes. Importantly, the nucleolin targeting aptamer, AS1411, exhibits selective anti-cancer activity in these cells and mislocalizes TBX3 and nucleolin to the cytoplasm which correlates with the re-expression of the TBX3/nucleolin target tumor suppressors CDKN1A (p21^CIP1) and CDKN2A (p14^ARF). Our findings provide the first evidence that TBX3 requires nucleolin to promote features of sarcomagenesis and that disruption of the oncogenic TBX3-nucleolin interaction by AS1411 may be a novel approach for treating sarcomas.

Direct Water-Assisted Laser Desorption/Ionization Mass Spectrometry Lipidomic Analysis and Classification of Formalin-Fixed Paraffin-Embedded Sarcoma Tissues without Dewaxing

BACKGROUND

Formalin-fixed paraffin-embedded (FFPE) tissue has been the gold standard for routine pathology for general and cancer postoperative diagnostics. Despite robust histopathology, immunohistochemistry, and molecular methods, accurate diagnosis remains difficult for certain cases. Overall, the entire process can be time consuming, labor intensive, and does not reach over 90% diagnostic sensitivity and specificity. There is a growing need in onco-pathology for adjunct novel rapid, accurate, reliable, diagnostically sensitive, and specific methods for high-throughput biomolecular identification. Lipids have long been considered only as building blocks of cell membranes or signaling molecules, but have recently been introduced as central players in cancer. Due to sample processing, which limits their detection, lipid analysis directly from unprocessed FFPE tissues has never been reported.

METHODS

We present a proof-of-concept with direct analysis of tissue-lipidomic signatures from FFPE tissues without dewaxing and minimal sample preparation using water-assisted laser desorption ionization mass spectrometry and deep-learning.

RESULTS

On a cohort of difficult canine and human sarcoma cases, classification for canine sarcoma subtyping was possible with 99.1% accuracy using "5-fold" and 98.5% using "leave-one-patient out," and 91.2% accuracy for human sarcoma using 5-fold and 73.8% using leave-one-patient out. The developed classification model enabled stratification of blind samples in <5 min and showed >95% probability for discriminating 2 human sarcoma blind samples.

CONCLUSION

It is possible to create a rapid diagnostic platform to screen clinical FFPE tissues with minimal sample preparation for molecular pathology.

Liquid Biopsies in Sarcoma Clinical Practice: Where Do We Stand?

Sarcomas are rare tumors of bone and soft tissue with a mesenchymal origin. This uncommon type of cancer is marked by a high heterogeneity, consisting of over 70 subtypes. Because of this broad spectrum, their treatment requires a subtype-specific therapeutic approach. Tissue biopsy is currently the golden standard for sarcoma diagnosis, but it has its limitations. Over the recent years, methods to detect, characterize, and monitor cancer through liquid biopsy have evolved rapidly. The analysis of circulating biomarkers in peripheral blood, such as circulating tumor cells (CTC) or circulating tumor DNA (ctDNA), could provide real-time information on tumor genetics, disease state, and resistance mechanisms. Furthermore, it traces tumor evolution and can assess tumor heterogeneity. Although the first results in sarcomas are encouraging, there are technical challenges that need to be addressed for implementation in clinical practice. Here, we summarize current knowledge about liquid biopsies in sarcomas and elaborate on different strategies to integrate liquid biopsy into sarcoma clinical care.

Molecular mechanisms underpinning sarcomas and implications for current and future therapy

Sarcomas are complex mesenchymal neoplasms with a poor prognosis. Their clinical management is highly challenging due to their heterogeneity and insensitivity to current treatments. Although there have been advances in understanding specific genomic alterations and genetic mutations driving sarcomagenesis, the underlying molecular mechanisms, which are likely to be unique for each sarcoma subtype, are not fully understood. This is in part due to a lack of consensus on the cells of origin, but there is now mounting evidence that they originate from mesenchymal stromal/stem cells (MSCs). To identify novel treatment strategies for sarcomas, research in recent years has adopted a mechanism-based search for molecular markers for targeted therapy which has included recapitulating sarcomagenesis using in vitro and in vivo MSC models. This review provides a comprehensive up to date overview of the molecular mechanisms that underpin sarcomagenesis, the contribution of MSCs to modelling sarcomagenesis in vivo, as well as novel topics such as the role of epithelial-to-mesenchymal-transition (EMT)/mesenchymal-to-epithelial-transition (MET) plasticity, exosomes, and microRNAs in sarcomagenesis. It also reviews current therapeutic options including ongoing pre-clinical and clinical studies for targeted sarcoma therapy and discusses new therapeutic avenues such as targeting recently identified molecular pathways and key transcription factors.

Follow-up Strategies for Primary Extremity Soft-tissue Sarcoma in Adults: A Systematic Review of the Published Literature

AIM

Follow-up strategies for primary extremity soft-tissue sarcomas (eSTS) in adults were evaluated in a systematic review of the published literature.

MATERIAL AND METHODS

The published literature was reviewed using PubMed. Of 136,646 studies published between 1985 and 2019, 78 original articles met the inclusion criteria. Articles were selected on the basis of the PRISMA guidelines. The selected articles were then cross-searched to identify further publications. August 1, 2019 was used as the concluding date of publication.

RESULTS

A variety of follow-up schedules have been reported in recently published literature. Two official guidelines have been approved by international societies. The guidelines distinguish between high- and low-grade STS, but mention a wide range of follow-up intervals. Established tools of follow-up include computed tomograph, X-rays of the chest, and magnetic resonance imaging of the primary tumor site in addition to clinical observation and physical examination.

CONCLUSION

Further research will be needed to establish evidence-based guidelines and schedules for follow-up strategies in patients with eSTS.

Paediatric soft tissue sarcomas in a resource constraint setting: Grade and stage at presentation and at oncologic intervention are usually of poor prognostic characteristics

AIM

To describe the pattern of paediatric Rhabdomyosarcomas (RMS) and Non-Rhabdomyosarcomas (NRMS) with emphasis on the indices that affect survival outcomes.

METHODS

We reviewed all patients with histologically confirmed RMS and NRMS in the Departments of Pathology and Paediatrics, University College Hospital (UCH), Ibadan, Nigeria; in children aged 0-14 years. The study period was January 1991 to December 2016. Information obtained included age, gender, morphology and site of the tumours. The tumour grade and pathologic/clinical staging of all patients were also obtained and verified by the clinical records. Tumour grading was carried out using the Fédération Nationale des Centres de Lutte Contre le Cancer (FNCLCC) Sarcoma group grading system and staging was done using TNM. Follow up, survival information and final outcome were retrieved.

RESULTS

The 104 patients included in the study had almost equal male-to-female ratio, age ranged between 5 months and 14 years (median 8.2 years). Rhabdomyosarcoma had mean age of 5.6 (±3.8) years while that of NRMS was 9.2(±4.1) years. Overall, the modal age group was 5-9 years. Rhabdomyosarcoma was the commonest histological type (76%), undifferentiated sarcomas (6.7%), fibrosarcoma (3.8%) and 2.9% each for synovial sarcoma and dermatofibrosarcoma protuberans. The common primary sites were the head and neck (including the orbit) 49 (47.1%), and the abdominopelvic 26 (25%) regions. Majority (89%) had histologic grade 3 at presentation. Seventy per cent and 64% of patients with RMS and NRMS, respectively, had high stage tumour at presentation. Median survival for all patients with Rhabdomyosarcoma was 45 weeks with a 1-year survival of 43% and 2-year survival of 25%. Non-RMS (Dermatofibrosarcoma protuberans and Solitary fibrous tumours) had survival of over 4 year's duration.

CONCLUSION

Majority of our patients presented at a late stage with histologic high grade which confers poor prognosis and reduced chances for good overall survival outcome.

Magnetic Resonance Imaging-Based Radiomics Nomogram for Prediction of the Histopathological Grade of Soft Tissue Sarcomas: A Two-Center Study

BACKGROUND

Preoperative prediction of soft tissue sarcoma (STS) grade is important for treatment decisions. Therefore, formulation an STS grade model is strongly needed.

PURPOSE

To develop and test an magnetic resonance imaging (MRI)-based radiomics nomogram for predicting the grade of STS (low-grade vs. high grade).

STUDY TYPE

Retrospective POPULATION: One hundred and eighty patients with STS confirmed by pathologic results at two independent institutions were enrolled (training set, N = 109; external validation set, N = 71).

FIELD STRENGTH/SEQUENCE

Unenhanced T1-weighted (T1WI) and fat-suppressed T2-weighted images (FS-T2WI) were acquired at 1.5 T and 3.0 T.

ASSESSMENT

Clinical-MRI characteristics included age, gender, tumor-node-metastasis (TNM) stage, American Joint Committee on Cancer (AJCC) stage, progression-free survival (PFS), and MRI morphological features (ie, margin). Radiomics feature extraction were performed on T1WI and FS-T2WI images by minimum redundancy maximum relevance (MRMR) method and least absolute shrinkage and selection operator (LASSO) algorithm. The selected features constructed three radiomics signatures models (RS-T1， RS-FST2, and RS-Combined). Univariate and multivariate logistic regression analysis were applied for screening significant risk factors. Radiomics nomogram was constructed by incorporating the radiomics signature and risk factors.

STATISTICAL TESTS

Clinical-MRI characteristics were performed by a univariate analysis. Model performances (discrimination, calibration, and clinical usefulness) were validated in the external validation set. The RS-T1 model, RS-FST2 model, and RS-Combined model had an area under curves (AUCs) of 0.645, 0.641, and 0.829, respectively, in the external validation set. The radiomics nomogram, incorporating significant risk factors and the RS-Combined model had AUCs of 0.916 (95%CI, 0.866-0.966, training set) and 0.879 (95%CI, 0.791-0.967, external validation set), and demonstrated good calibration and good clinical utility.

DATA CONCLUSION

The proposed noninvasive MRI-based radiomics models showed good performance in differentiating low-grade from high-grade STSs.

LEVEL OF EVIDENCE

3 TECHNICAL EFFICACY STAGE: 2.

Detection of Structural Variants in Circulating Cell-Free DNA from Sarcoma Patients Using Next Generation Sequencing

Circulating tumour DNA (ctDNA) analysis using next generation sequencing (NGS) is being implemented in clinical practice for treatment stratification and disease monitoring. However, using ctDNA to detect structural variants, a common occurrence in sarcoma, can be challenging. Here, we use a sarcoma-specific targeted NGS panel to identify translocations and copy number variants in a cohort of 12 tissue specimens and matched circulating cell-free DNA (cfDNA) from soft tissue sarcoma patients, including alveolar rhabdomyosarcoma (n = 2), Ewing's Sarcoma (n = 2), synovial sarcoma (n = 2), extraskeletal myxoid chondrosarcoma (n = 1), clear cell sarcoma (n = 1), undifferentiated round cell sarcoma (n = 1), myxoid liposarcoma (n = 1), alveolar soft part cell sarcoma (n = 1) and dedifferentiated liposarcoma (n = 1). Structural variants were detected in 11/12 (91.6%) and 6/12 (50%) of tissue and plasma samples, respectively. Structural variants were detected in cfDNA at variant allele frequencies >0.2% with an average sequencing depth of 1026×. The results from this cohort show clinical potential for using NGS in ctDNA to aid in the diagnosis and clinical monitoring of sarcomas and warrant additional studies in larger cohorts.

Microvascular tissue transfer after the resection of soft tissue sarcomas

BACKGROUND

Microvascular tissue transfer enables the oncological resection of soft tissue sarcomas of the extremities and the trunk by covering the resulting tissue defects that are often extensive. This study was performed to investigate the long-term survival and functional outcome of patients treated with free flaps after sarcoma resection.

METHODS

A total of 78 sarcoma patients received microvascular tissue transfer in our institution between March 2003 and January 2013. In a retrospective analysis, we investigated data such as tumor characteristics as well as survival time and disease-free survival. In a prospective analysis, we assessed the functional outcome and the health-associated quality of life with the TESS and SF-36 questionnaire, respectively.

RESULTS

Seventy patients qualified for disease-free survival after tumor resection, 41 patients remained disease free for over 5 years. Forty-five patients reached a survival time of more than 5 years. The functional results experienced by our patients were good with a mean score of 82.6% in the TESS. The physical health-related quality was lower than in the German norm sample and patients suffering from chronical illnesses or cancer, whereas the mental health was only slightly lower than in the norm sample and higher than in the groups with chronic illnesses or cancer (SF-36).

CONCLUSION

Microvascular tissue transfer enables tumor resection and limb salvage through the coverage of the resulting defects without impairing patients' prognosis. The long survival times after tumor resection emphasizes the need for good functional results as well as quality of life.

Identification of Subtype-Specific Metastasis-Related Genetic Signatures in Sarcoma

Background: Sarcomas are heterogeneous rare malignancies constituting approximately 1% of all solid cancers in adults and including more than 70 histological and molecular subtypes with different pathological and clinical development characteristics.

Method: We identified prognostic biomarkers of sarcomas by integrating clinical information and RNA-seq data from TCGA and GEO databases. In addition, results obtained from cell cycle, cell migration, and invasion assays were used to assess the capacity for Tanespimycin to inhibit the proliferation and metastasis of sarcoma.

Results: Sarcoma samples (N = 536) were divided into four pathological subtypes including DL (dedifferentiated liposarcoma), LMS (leiomyosarcoma), UPS (undifferentiated pleomorphic sarcomas), and MFS (myxofibrosarcoma). RNA-seq expression profile data from the TCGA dataset were used to analyze differentially expressed genes (DEGs) within metastatic and non-metastatic samples of these four sarcoma pathological subtypes with DEGs defined as metastatic-related signatures (MRS). Prognostic analysis of MRS identified a group of genes significantly associated with prognosis in three pathological subtypes: DL, LMS, and UPS. ISG15, NUP50, PTTG1, SERPINE1, and TSR1 were found to be more likely associated with adverse prognosis. We also identified Tanespimycin as a drug exerting inhibitory effects on metastatic LMS subtype and therefore can serve a potential treatment for this type of sarcoma.

Conclusions: These results provide new insights into the pathogenesis, diagnosis, treatment, and prognosis of sarcomas and provide new directions for further study of sarcoma.

Efficacy and safety of apatinib in advanced sarcoma: an open-label, nonrandomized, single-center study of 45 patients

Sarcoma is a rare tumor with more than 50 histologic subtypes. Patients with advanced sarcoma have a poor prognosis. The aim of this study was to evaluate the efficacy and safety of apatinib, an oral vascular endothelial growth factor receptor-2 inhibitor, as salvage treatment for advanced bone and soft tissue sarcomas. From May 2017 to July 2018, a prospective, open-label, nonrandomized, clinical trial of apatinib was carried out in selected patients with advanced sarcoma. After apatinib dosing, progression-free survival (PFS), overall survival (OS), objective response rate, disease control rate, and treatment-related adverse events (AEs) were reviewed and evaluated. Patients were administered apatinib for at least 1 month. Median follow-up time was 6.00 months (1-13 months). The median PFS was 7.88 months, with the longest PFS of 13 months observed in a patient with epithelial sarcoma. The 3-month PFS rate was 66.44%. The median OS was 11.64 months with significant differences observed based on disease subtypes. Four patients achieved a partial response, and 36 patients achieved stable disease. The objective response rate was 8.88% (4/45), and the disease control rate was 88.89% (40/45). The most common grade 3/4 treatment-related AEs were hypertension (12.50%), hand-foot syndrome (6.67%), diarrhea (12.50%), fatigue (6.25%), and proteinuria (14.29%). One drug-related severe AE of thrombocytopenia (21×10/l) occurred 2 months after therapy. Apatinib treatment in our study exhibited objective efficacy in PFS, OS, and manageable toxicity in patients with advanced sarcoma. This result supports future randomized controlled trials to further define apatinib activity in stage IV sarcomas.

Immunotherapy with nivolumab for the treatment of soft tissue sarcoma with pulmonary metastasis: A case report

Sarcomas are an unusual group of tumors, accounting for ~1% of cancer in adults. Immunotherapy has been shown to be a potential therapeutic option for the management of patients with cancer. However, there is still insufficient information on the action of immunotherapy on sarcomas. A 16-year-old male patient, diagnosed in December 2013 with grade III soft-tissue sarcoma in the right arm, was admitted to a private oncology service after relapse following surgical treatment. The patient underwent chemotherapy with ifosfamide plus adriamycin for 4 cycles, associated with adjuvant radiotherapy, followed by a new resection to remove the residual lesion. A year later, imaging tests identified pulmonary micronodules, and a new resection was performed. After immunohistochemical evaluation of biopsy, a large presence of programmed cell death 1 ligand 1 (PD-L1) marker was identified in tumor tissue and immunotherapy with nivolumab was performed. At present, the patient is in immunotherapeutic treatment (42 cycles), presenting an excellent general condition and without any symptoms, and a decrease in neoplastic lung masses. The literature recommends three cycles of anthracycline plus ifosfamide as adjuvant therapy to surgical treatment. Combined surgery plus adjuvant therapy has shown benefits in malignant tumors. Immunotherapy is an important therapeutic option for soft-tissue sarcomas with high programmed cell death protein 1 (PD-1)/PD-L1 expression. Treatment for high grade soft tissue sarcoma (STS) is still limited, due to tumor heterogeneity, and further studies are needed to consolidate the possibility of using immunotherapy to treat these neoplasms. When significant levels of specific biomarkers are present in tumor tissue, immunotherapy may be beneficial as shown by the present case report.

Antiproliferative effect of bupivacaine on patient-derived sarcoma cells

Sarcomas are rare tumors with limited treatment options. Although chemotherapy is standard for certain subtypes, overall survival has not improved in several decades. Bupivacaine has been shown to induce apoptosis and prevent cell growth in multiple different types of malignancies but has not been studied in sarcoma. The current study evaluated the effects of bupivacaine on multiple patient-derived sarcoma cells and a commercial sarcoma cell line. Multiple patient-derived sarcoma cell subtypes and a commercial synovial cell sarcoma cell line were exposed to bupivacaine for different durations and at different concentrations. The patient-derived cells included a high-grade conventional osteosarcoma, a high-grade undifferentiated pleomorphic sarcoma of bone, and a high-grade synovial sarcoma. Flow cytometry and an MTT assay were used to evaluate whether a treatment effect was observed. Treatment of all the subtypes of sarcomas in this study with bupivacaine demonstrated a time- and dose-dependent increase in apoptosis and decrease in cell viability. A cell viability assay demonstrated that the IC₅₀ was between 0.04 and 0.05% and that the treatment effect occurred at clinically relevant doses in vitro. Bupivacaine was toxic to both the patient-derived cells and the commercial cell line at doses commonly used in the clinical setting. These findings provide a foundation for further in vivo studies to evaluate whether these effects will translate to the clinical setting. Although further research is necessary, bupivacaine shows promise as not only an adjunct for pain management but as a treatment modality for sarcoma.

CDKs in Sarcoma: Mediators of Disease and Emerging Therapeutic Targets

Sarcomas represent one of the most challenging tumor types to treat due to their diverse nature and our incomplete understanding of their underlying biology. Recent work suggests cyclin-dependent kinase (CDK) pathway activation is a powerful driver of sarcomagenesis. CDK proteins participate in numerous cellular processes required for normal cell function, but their dysregulation is a hallmark of many pathologies including cancer. The contributions and significance of aberrant CDK activity to sarcoma development, however, is only partly understood. Here, we describe what is known about CDK-related alterations in the most common subtypes of sarcoma and highlight areas that warrant further investigation. As disruptions in CDK pathways appear in most, if not all, subtypes of sarcoma, we discuss the history and value of pharmacologically targeting CDKs to combat these tumors. The goals of this review are to (1) assess the prevalence and importance of CDK pathway alterations in sarcomas, (2) highlight the gap in knowledge for certain CDKs in these tumors, and (3) provide insight into studies focused on CDK inhibition for sarcoma treatment. Overall, growing evidence demonstrates a crucial role for activated CDKs in sarcoma development and as important targets for sarcoma therapy.

Treatment Patterns and Healthcare Resource Utilization among Patients with Advanced or Metastatic Soft Tissue Sarcoma in US Community Practices

INTRODUCTION

This study was designed to describe demographic and clinical characteristics of patients diagnosed with advanced or metastatic soft tissue sarcoma (STS) and to examine treatment and healthcare resource utilization patterns of this patient population in a United States (US) community-based oncology practice setting over time.

METHODS AND MATERIALS

A retrospective observational study was conducted within the US Oncology Network (USON). Patients were eligible if they were diagnosed with advanced or metastatic STS and were treated at a USON site between 01 July 2015 and 31 August 2018. Demographic, clinical, and treatment characteristics were described for the overall study population. Comparisons between patients by time period (prior to and after October 2016) were evaluated using the T test for continuous variables and chi-squared test for categorical variables. Data were available for analysis through 31 August 2018.

RESULTS

Demographic and clinical characteristics of the eligible study cohort (N = 376) were similar between patients who initiated treatment before and after October 2016 (all p > 0.05). Forty-three unique regimens were observed in the first-line setting, with the predominant regimen (gemcitabine + docetaxel) received by 33.2% (n = 125) patients. Prior to October 2016, 45.4% of patients received first-line gemcitabine + docetaxel, while 29.0% received this regimen after October 2016.

CONCLUSIONS

While demographic and clinical characteristics were similar, treatment patterns changed in 2016. Future research should evaluate the impact of changing drug approvals and clinical trial results on future treatment patterns.

Boosting Natural Killer Cell-Mediated Targeting of Sarcoma Through DNAM-1 and NKG2D

Sarcomas are malignancies of mesenchymal origin that occur in bone and soft tissues. Many are chemo- and radiotherapy resistant, thus conventional treatments fail to increase overall survival. Natural Killer (NK) cells exert anti-tumor activity upon detection of a complex array of tumor ligands, but this has not been thoroughly explored in the context of sarcoma immunotherapy. In this study, we investigated the NK cell receptor/ligand immune profile of primary human sarcoma explants. Analysis of tumors from 32 sarcoma patients identified the proliferative marker PCNA and DNAM-1 ligands CD112 and/or CD155 as commonly expressed antigens that could be efficiently targeted by genetically modified (GM) NK cells. Despite the strong expression of CD112 and CD155 on sarcoma cells, characterization of freshly dissociated sarcomas revealed a general decrease in tumor-infiltrating NK cells compared to the periphery, suggesting a defect in the endogenous NK cell response. We also applied a functional screening approach to identify relevant NK cell receptor/ligand interactions that induce efficient anti-tumor responses using a panel NK-92 cell lines GM to over-express 12 different activating receptors. Using GM NK-92 cells against primary sarcoma explants (n = 12) revealed that DNAM-1 over-expression on NK-92 cells led to efficient degranulation against all tested explants (n = 12). Additionally, NKG2D over-expression showed enhanced responses against 10 out of 12 explants. These results show that DNAM-1⁺ or NKG2D⁺ GM NK-92 cells may be an efficient approach in targeting sarcomas. The degranulation capacity of GM NK-92 cell lines was also tested against various established tumor cell lines, including neuroblastoma, Schwannoma, melanoma, myeloma, leukemia, prostate, pancreatic, colon, and lung cancer. Enhanced degranulation of DNAM-1⁺ or NKG2D⁺ GM NK-92 cells was observed against the majority of tumor cell lines tested. In conclusion, DNAM-1 or NKG2D over-expression elicited a dynamic increase in NK cell degranulation against all sarcoma explants and cancer cell lines tested, including those that failed to induce a notable response in WT NK-92 cells. These results support the broad therapeutic potential of DNAM-1⁺ or NKG2D⁺ GM NK-92 cells and GM human NK cells for the treatment of sarcomas and other malignancies.

A population-based study of soft tissue sarcoma incidence and survival in Australia: An analysis of 26,970 cases

BACKGROUND

Soft tissue sarcomas (STS) are rare, often fatal tumors, but little is known of the epidemiology and survival in the Australian population. This study aims to provide the first epidemiological analysis of incidence and survival rates of STS in the Australian population.

METHODS

A retrospective population-based observational study was conducted between 1982 and 2009 of all patients with a diagnosis of STS using the Australian Institute of Health and Welfare (AIHW) Australian Cancer Database. Incidence rates per 100,000; incidence rate ratios, age-standardized incidence rates, prevalence and incidence rates of subtypes of STS, median, one-year and 5-year survival rates were examined.

RESULTS

A total of 26,970 patients were identified. Between 1982 and 2009 STS incidence rates significantly increased from 3.99 [95% CI 3.68-4.32] to 6.12 [95% CI 5.80-6.46] per 100,000 Australian population, with a peak incident rate ratio (IRR) of 1.59 [95% CI 1.51-1.69] (p < 0.0001) in 2001. Median age at diagnosis increased from 58 to 63 years. Incidence rates were stable across all 10-year age cohorts, except for people aged over 70 where it increased. Overall, age-standardized incidence rates increased from 4.70 [95% CI 4.42-5.00] in 1982 to 5.87 [95% CI 5.63-6.11] per 100 000 Australians in 2009. Leiomyosarcoma (20.43%), malignant fibrous histiocytoma (16.14%), and soft tissue tumors/sarcomas, not otherwise specified (10.18%) were the most common STS subtypes. Median survival from diagnosis increased from 5.80 years [95% CI 5.06-6.54] in 1985-1989 cohort to 8.18 years [95% CI 7.54-8.81] in the 2000-2004 cohort (log-rank test p < 0.0001).

CONCLUSION

The incidence of STS is increasing in Australia, most noticeably in those aged over 70 years, with a small but statistically significant increase in overall survival rates.

Biology and Therapy of Dominant Fusion Oncoproteins Involving Transcription Factor and Chromatin Regulators in Sarcomas

A third of soft tissue sarcomas have been shown to carry recurrent, characteristic chromosomal translocations, many of which generate fusion proteins that act as dominant transcription factors or as chromatin regulators. With routine use of massively parallel sequencing and advances in technology for the study of epigenetics and protein complexes, the last decade has seen a marked advancement in the identification of novel fusions and in our understanding of the mechanisms by which they contribute to the malignant state. Moreover, with new approaches in chemistry, such as the strategy of targeted protein degradation, we are now better poised to address these previously intractable targets. In this review, we describe three of the most common fusion-driven sarcomas (Ewing sarcoma, alveolar rhabdomyosarcoma, and synovial sarcoma), mechanistic themes emerging across these diseases, and novel approaches to their targeting.

Real-Time Molecular Diagnosis of Tumors Using Water-Assisted Laser Desorption/Ionization Mass Spectrometry Technology

Histopathological diagnosis of biopsy samples and margin assessment of surgical specimens are challenging aspects in sarcoma. Using dog patient tissues, we assessed the performance of a recently developed technology for fast ex vivo molecular lipid-based diagnosis of sarcomas. The instrument is based on mass spectrometry (MS) molecular analysis through a laser microprobe operating under ambient conditions using excitation of endogenous water molecules. Classification models based on cancer/normal/necrotic, tumor grade, and subtypes showed a minimum of 97.63% correct classification. Specific markers of normal, cancer, and necrotic regions were identified by tandem MS and validated by MS imaging. Real-time detection capabilities were demonstrated by ex vivo analysis with direct interrogation of classification models.

Human mesenchymal stromal cells do not promote recurrence of soft tissue sarcomas in mouse xenografts after radiation and surgery

BACKGROUND

Mesenchymal stromal cells (MSCs) promote wound healing, including after radiotherapy (RT) and surgery. The use of MSCs in regenerative medicine in the context of malignancy, such as to enhance wound healing post-RT/surgery in patients with soft tissue sarcomas (STSs), requires safety validation. The aim of this study was to determine the effects of human MSCs on STS growth in vitro and local recurrence and metastasis in vivo.

METHODS

Human primary STS and HT-1080 fibrosarcoma lines were transduced to express luciferase/eGFP (enhanced green fluorescent protein). Sarcoma cells were co-cultured or co-injected with bone marrow-derived MSCs for growth studies. Xenograft tumor models were established with STS lines in NOD/SCID/γ_c^null mice. To emulate a clinical scenario, subcutaneous tumors were treated with RT/surgery prior to MSC injection into the tumor bed. Local and distant tumor recurrence was studied using histology and bioluminescence imaging.

RESULTS

MSCs did not promote STS proliferation upon co-culture in vitro, which was consistent among MSCs from different donors. Co-injection of MSCs with sarcoma cells in mice exhibited no significant tumor-stimulating effect, compared with control mice injected with sarcoma cells alone. MSC administration after RT/surgery had no effect on local recurrence or metastasis of STS.

DISCUSSION

These studies are important for the establishment of a safety profile for MSC administration in patients with STS. Our data suggest that MSCs are safe in STS management after standard of care RT/surgery, which can be further investigated in early-phase clinical trials to also determine the efficacy of MSCs in reducing morbidity and to mitigate wound complications in these patients.

A k-mer based transcriptomics approach for antisense drug discovery targeting the Ewing's family of tumors

Ewing’s sarcoma treatment failures are associated with high mortality indicating a need for new therapeutic approaches. We used a k-mer counting approach to identify cancer-specific mRNA transcripts in 3 Ewing’s Family Tumor (EFT) cell lines not found in the normal human transcriptome. Phosphorodiamidate morpholino oligomers targeting six EFT-specific transcripts were evaluated for cytotoxicity in TC-32 and CHLA-10 EFT lines and in HEK293 renal epithelial control cells. Average morpholino efficacy (EC₅₀) was 0.66 ± 0.13 in TC-32, 0.25 ± 0.14 in CHLA-10 and 3.07 ± 5.02 µM in HEK293 control cells (ANOVA p < 0.01). Synergy was observed for a cocktail of 12 morpholinos at low dose (0.3 µM) in TC-32 cells, but not in CHLA-10 cells. Paired synergy was also observed in both EFT cell lines when the PHGDH pre-mRNA transcript was targeted in combination with XAGE1B or CYP4F22 transcripts. Antagonism was observed when CCND1 was targeted with XAGE1B or CYP4F22, or when IGFBP-2 was targeted with CCND1 or RBM11. This transcriptome profiling approach is highly effective for cancer drug discovery, as it identified new EWS-specific target genes (e.g. CYP4F22, RBM11 and IGBP-2), and predicted effective antisense agents (EC₅₀ < 1 µM) that demonstrate both synergy and antagonism in combination therapy.

Role of interventional radiology in the management of musculoskeletal soft-tissue lesions

The lesions of the soft tissues are rare and extremely heterogeneous; even if the surgical treatment is usually the standard therapy, the role of the interventional radiology (IR) in this field is growing up for multiple reasons. First, because the imaging alone usually is not able to ensure a definitive diagnosis, IR has a basic role in the staging: the percutaneous biopsy is infact an irreplaceable step. Moreover, biopsy is necessary not only for histologic evaluations but also for the biochemical and molecular studies. Furthermore, the proved safety and effectiveness of IR in a multiple oncologial applications prompt a wider use also in this field.

Safety of concurrent adjuvant radiotherapy and chemotherapy for locally advanced soft tissue sarcoma

INTRODUCTION:

This retrospective study analyzes the safety and feasibility of concurrent chemoradiotherapy (CRT) in adjuvant treatment of soft tissue sarcoma (STS).

METHODS:

A total of 158 patients with STS were retrospectively analyzed. Anthracycline-based computed tomography was performed in high-risk patients. Acute radiotherapy toxicity and chemotherapy-related toxicity were assessed according to the Common Terminology Criteria for Adverse Events 4.0; late radiotherapy toxicity was recorded according to Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer criteria.

RESULTS:

Fifty-four (34.2%) patients received CRT. Mean follow up was 5.4 years (range .2-21.1 years). Local DFS-recurrence-free survival, distant DFS-relapse-free survival, and overall survival were 79.1%, 76.4%, and 64.6%, respectively, at last follow-up. Leukopenia occurred in 11.4% of patients. Skin acute toxicity developed in 60.1% of patients and determined interruption of radiotherapy treatment in 19 (12%) patients. Nineteen patients (12%) experienced moderate fibrosis (grade 2). Mild and moderate joint stiffness was recorded in 16 (10.1%) patients. Size ≥5 cm was the only predictor of local recurrence at multivariate analysis (hazard ratio [HR] 9.65, 95% confidence interval [CI] 1.28-72.83, p = .028). Age and stage resulted as independent distant relapse predictors (HR 4.77, 95% CI 1.81-12.58, p = .002 and HR 4.83, CI 1.41-16.57, p = .012, respectively). At Cox regression univariate analysis, Karnofsky Performance Status, size, and stage were significant survival predictors (HR 2.23, 95% CI 1.02-4.87, p = .045; HR 2.88, 95% CI 1.10-7.52, p = .031; HR 2.59, 95% CI 1.11-6.04, p = .028).

CONCLUSIONS:

Concurrent CRT is a well-tolerated treatment option with no additional toxicity compared to exclusive radiotherapy or sequential CRT.

Evaluation of information presented within soft tissue sarcoma histopathology reports in the United States: 2012-2015

Despite the existence of the American College of Veterinary Pathology guidelines for tumour biopsy specimens, anecdotally the authors' have seen inconsistency of reporting of information on the pathology report for canine soft tissue sarcomas (STSs). If crucial aspects are not reported this can result in slower or impeded patient care. This retrospective study evaluated 255 STS histopathology reports submitted from across the United States. Reports were evaluated by a single observer to assess for information contained in 5 main categories: patient history and signalment, gross and microscopic description, grading, histologic margins and the comments section. Inclusion criteria for histopathology reports included a final diagnosis of STS, having a microscopic description and resulting from the initial surgical resection. The majority of the reports stated the patient signalment (91.2%) and clinical history (90.8%). However, only 64.8% of the reports had a gross description of the specimen. Histologic margin description was present in 229 reports (91.6%), however, only 149 reports (59.6%) stated an objective measurement of these margins. Histologic classification was stated in 50.0% of the reports, while grade was given on 97.2% of the reports. Variability in histopathologic reporting including histologic margin description for resected canine STS was identified. Given surgical treatment is the mainstay for STS and histopathological assessment plays an important role in determination of whether additional surgery, radiation or chemotherapy is needed. Standardization or checklists like the American College of Pathology utilize may be helpful to ensure histopathologic characteristics are reported that may guide further treatment recommendations.

Disruption of mammalian SWI/SNF and polycomb complexes in human sarcomas: mechanisms and therapeutic opportunities

Soft-tissue sarcomas are increasingly characterized and subclassified by genetic abnormalities that represent underlying drivers of their pathology. Hallmark tumor suppressor gene mutations and pathognomonic gene fusions collectively account for approximately one-third of all sarcomas. These genetic abnormalities most often result in global transcriptional misregulation via disruption of protein regulatory complexes which govern chromatin architecture. Specifically, alterations to mammalian SWI/SNF (mSWI/SNF or BAF) ATP-dependent chromatin remodeling complexes and polycomb repressive complexes cause disease-specific changes in chromatin architecture and gene expression across a number of sarcoma subtypes. Understanding the functions of chromatin regulatory complexes and the mechanisms underpinning their roles in oncogenesis will be required for the design and development of new therapeutic strategies in sarcomas. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.