Tyrosine kinase inhibitors in sarcoma treatment

Comprehensive study of gene fusions in sarcomas

Sarcomas, including bone sarcomas and soft tissue sarcomas (STSs), are a heterogeneous group of mesenchymal malignancies. Recent advancements in next-generation sequencing (NGS) have enabled the identification of novel chromosomal translocations and fusion genes, which play a critical role in sarcoma subtypes. Our study focuses on gene fusions in sarcomas among Chinese patients, comparing their genomic profiles to those of Western populations. We analyzed 1048 sarcoma samples from Chinese patients using a panel of over 500 genes, identifying 481 gene fusions in 329 patients. The most common fusions included EWSR1, HMGA2, and SS18, with notable subtype-specific fusions such as EWSR1-FLI1 in Ewing sarcoma and NAB2-STAT6 in solitary fibrous tumors. In comparison to Chinese and Western populations, variations in fusion spectrum exist, potentially necessitating distinct treatment strategies; however, further validation of these fusions is warranted. Our findings highlight the importance of gene fusions as diagnostic markers and potential therapeutic targets. Actionable fusions, including kinase-related fusions like ALK, NTRK3, and BRAF, were detected in 67 patients (6.4%) and may guide precision therapies. Additionally, we observed the frequent co-occurrence of genomic alterations, particularly in cell cycle regulators such as CDK4 and MDM2. Genomic profiling of sarcomas offers valuable insights into their molecular drivers and can support personalized therapeutic approaches. Further research is needed to validate these findings and optimize treatment strategies for sarcoma patients.

Treatments and prognostic factors for bone and soft tissue sarcoma in non-urban areas in Japan

BACKGROUND

Although bone and soft tissue sarcoma is recognized as a rare cancer that originates throughout the body, few comprehensive reports regarding it have been published in Japan.

PATIENTS AND METHODS

Bone and soft tissue sarcomas were tabulated from the Cancer Registries at eight university hospitals in the Chugoku-Shikoku region. Prognostic factors in cases were extracted in a single facility and have been analyzed.

RESULTS

From 2016 to 2019, 3.4 patients with bone and soft tissue sarcomas per a general population of 100,000 were treated at eight university hospitals. The number of patients who underwent multidisciplinary treatment involving collaboration among multiple clinical departments has been increasing recently. In the analysis carried out at a single institute (Ehime University Hospital), a total of 127 patients (male/female: 54/73) with an average age of 67.0 y (median 69.5) were treated for four years, with a 5-year survival rate of 55.0%. In the analysis of prognostic factors by multivariate, disease stage and its relative treatment, renal function (creatinine), and a patient's ability of self-judgment, and a patient's mobility and physical capability were associated with patient prognosis regarding bone and soft tissue sarcomas. Interestingly, age did not affect the patient's prognosis (> 70 vs ≦ 70).

CONCLUSIONS

Physical and social factors may affect the prognosis of patients with bone and soft tissue sarcomas, especially those living in non-urban areas.

Establishment and functional testing of a novel ex vivo extraskeletal osteosarcoma cell model (USZ20-ESOS1)

Extraskeletal osteosarcoma (ESOS) is a rare malignant mesenchymal tumor that originates in the soft tissue. ESOS accounts for less than 1% of all soft tissue sarcomas and exhibits an aggressive behavior with a high propensity for local recurrence and distant metastasis. Despite advances in treatment, the prognosis for ESOS remains poor, with a five-year survival rate of less than 50% and 27% for metastatic patients. Ex vivo models derived from patient samples are critical tools for studying rare diseases with poor prognoses, such as ESOS, and identifying potential new treatment strategies. In this work, we established a novel ESOS ex vivo sarco-sphere model from a metastatic lesion to the dermis for research and functional testing purposes. The ex vivo cell model accurately recapitulated the native tumor, as evidenced by histomorphology and molecular profiles. Through a functional screening approach, we were able to identify novel individual anti-cancer drug sensitivities for different drugs such as romidepsin, miverbresib and to multiple kinase inhibitors. Overall, our new ESOS ex vivo cell model represents a valuable tool for investigating disease mechanisms and answering basic and translational research questions.

Targeted Inhibition of the PI3K/Akt/mTOR Signaling Axis: Potential for Sarcoma Therapy

Sarcoma is a heterogeneous group of malignancies often resistant to conventional chemotherapy and radiation therapy. The phosphatidylinositol-3-kinase/ protein kinase B /mammalian target of rapamycin (PI3K/Akt/mTOR) signaling pathway has emerged as a critical cancer target due to its central role in regulating key cellular processes such as cell growth, proliferation, survival, and metabolism. Dysregulation of this pathway has been implicated in the development and progression of bone sarcomas (BS) and soft tissue sarcomas (STS). PI3K/Akt/mTOR inhibitors have shown promising preclinical and clinical activity in various cancers. These agents can inhibit the activation of PI3K, Akt, and mTOR, thereby reducing the downstream signaling events that promote tumor growth and survival. In addition, PI3K/Akt/mTOR inhibitors have been shown to enhance the efficacy of other anticancer therapies, such as chemotherapy and radiation therapy. The different types of PI3K/Akt/mTOR inhibitors vary in their specificity, potency, and side effect profiles and may be effective depending on the specific sarcoma type and stage. The molecular targeting of PI3K/Akt/mToR pathway using drugs, phytochemicals, nanomaterials (NMs), and microbe-derived molecules as Pan-PI3K inhibitors, selective PI3K inhibitors, and dual PI3K/mTOR inhibitors have been delineated. While there are still challenges to be addressed, the preclinical and clinical evidence suggests that these inhibitors may significantly improve patient outcomes. Further research is needed to understand the potential of these inhibitors as sarcoma therapeutics and to continue developing more selective and effective agents to meet the clinical needs of sarcoma patients.

A Scoping Review on Tyrosine Kinase Inhibitors in Cats: Current Evidence and Future Directions

Tyrosine kinase inhibitors (TKIs) have become invaluable in the treatment of human and canine malignancies, but their role in feline oncology is less defined. While toceranib phosphate and masitinib mesylate are licensed for use in dogs, no TKI is yet approved for cats. This review systematically maps the research conducted on the expression of tyrosine kinases in neoplastic and non-neoplastic domestic feline tissues, as well as the in vitro/in vivo use of TKIs in domestic cats. We identify and discuss knowledge gaps and speculate on the further research and potential indications for TKI use in cats. A comprehensive search of three electronic databases and relevant paper reference lists identified 139 studies meeting the inclusion criteria. The most commonly identified tumors were mast cell tumors (MCTs), mammary and squamous cell carcinomas and injection-site sarcomas. Based on the current literature, toceranib phosphate appears to be the most efficacious TKI in cats, especially against MCTs. Exploring the clinical use of TKIs in mammary carcinomas holds promise. Despite the progress, currently, the evidence falls short, underscoring the need for further research to discover new indications in feline oncology and to bridge the knowledge gaps between human and feline medicine.

Functional Profiling of Soft Tissue Sarcoma Using Mechanistic Models

Soft tissue sarcoma is an umbrella term for a group of rare cancers that are difficult to treat. In addition to surgery, neoadjuvant chemotherapy has shown the potential to downstage tumors and prevent micrometastases. However, finding effective therapeutic targets remains a research challenge. Here, a previously developed computational approach called mechanistic models of signaling pathways has been employed to unravel the impact of observed changes at the gene expression level on the ultimate functional behavior of cells. In the context of such a mechanistic model, RNA-Seq counts sourced from the Recount3 resource, from The Cancer Genome Atlas (TCGA) Sarcoma project, and non-diseased sarcomagenic tissues from the Genotype-Tissue Expression (GTEx) project were utilized to investigate signal transduction activity through signaling pathways. This approach provides a precise view of the relationship between sarcoma patient survival and the signaling landscape in tumors and their environment. Despite the distinct regulatory alterations observed in each sarcoma subtype, this study identified 13 signaling circuits, or elementary sub-pathways triggering specific cell functions, present across all subtypes, belonging to eight signaling pathways, which served as predictors for patient survival. Additionally, nine signaling circuits from five signaling pathways that highlighted the modifications tumor samples underwent in comparison to normal tissues were found. These results describe the protective role of the immune system, suggesting an anti-tumorigenic effect in the tumor microenvironment, in the process of tumor cell detachment and migration, or the dysregulation of ion homeostasis. Also, the analysis of signaling circuit intermediary proteins suggests multiple strategies for therapy.

Real-world experience of tyrosine kinase inhibitors in children, adolescents and adults with relapsed or refractory bone tumours: A Canadian Sarcoma Research and Clinical Collaboration (CanSaRCC) study

OBJECTIVES

We conducted a retrospective multi-centre study to assess the real-world outcome of regorafenib (REGO) and cabozantinib (CABO) in recurrent/refractory bone tumours (BTs) including osteosarcoma (OST), Ewing sarcoma (EWS) and chondrosarcoma (CS)/extra-skeletal mesenchymal CS (ESMC).

METHODS

After regulatory approval, data from patients with recurrent BT (11 institutions) were extracted from CanSaRCC (Canadian Sarcoma Research and Clinical Collaboration) database. Patient characteristics, treatment and outcomes were collected. Progression-free survival (PFS) and overall survival (OS) were estimated using the Kaplan-Meier method.

RESULTS

From July 2018 to May 2022, 66 patients received REGO or CABO; 39 OST, 18 EWS, 4 CS and 5 ESMC. Median age was 27.8 years (range 12-76); median starting dose was 60 mg for CABO (n = 37, range 40-60) and 120 mg for REGO (n = 29, range 40-160). Twenty-eight (42.4%) patients required dose reduction: hand-foot syndrome 7 (10.6%), nausea/vomiting 1 (1.5%), diarrhoea 1 (1.5%), 2 elevated LFTs (3%), elevated bilirubin 1 (1.5%) and mucositis 1 (1.5%). The median OS for patients with OST, EWS, CS and ESMC was 8.5 months (n = 39, 95% CI 7-13.1); 13.4 months (n = 18, 95% CI 3.4-27.2), 8.1 (n = 4, 95% CI 4.1-9.3) and 18.2 (n = 5, 95% CI (10.4-na), respectively. Median PFS for OST, EWS, CS and ECMS was 3.5 (n = 39, 95% CI 2.8-5), 3.9 (n = 18, 95% CI 2.1-5.9), 5.53 (n = 4. 95% CI 2.13-NA) and 11.4 (n = 5, 95% CI 1.83-14.7), respectively. Age, line of therapy, REGO versus CABO, or time from diagnosis to initiation of TKI were not associated with PFS on univariable analysis.

CONCLUSION

Our real-world data show that TKIs have meaningful activity in recurrent BT with acceptable toxicities when started at modified dosing. Inclusion of TKIs in earlier lines of treatment and/or maintenance therapy could be questions for future research.

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.

Head and Neck Mesenchymal Tumors with Kinase Fusions: A Report of 15 Cases With Emphasis on Wide Anatomic Distribution and Diverse Histologic Appearance

Mesenchymal tumors harboring various kinase fusions were recently recognized as emerging entities mainly in the soft tissues. We herein investigate the clinicopathologic and molecular characteristics of head and neck mesenchymal tumors harboring kinase fusions. The study cohort included 15 patients with a median age of 13 years (ranging from congenital to 63 y). The kinase genes involved in descending order were NTRK1 (n=6), NTRK3 (n=5), BRAF (n=2), and 1 each with MET, and RET. The anatomic locations were broad involving all tissue planes, including skin (n=4), intraosseous (n=4), major salivary glands (n=2), sinonasal tract (n=2), soft tissue of face or neck (n=2), and oral cavity (n=1). The histologic spectrum ranged from benign to high grade, in descending order including tumors resembling malignant peripheral nerve sheath tumor (MPNST)-like, fibrosarcoma (infantile or adult-type), lipofibromatosis-like neural tumor (LPFNT), inflammatory myofibroblastic tumor-like, and a novel phenotype resembling myxoma. Perivascular hyalinization/stromal keloid-like collagen bands and staghorn vasculature were common features in MPNST-like and LPFNT-like tumors. Two tumors (1 each with NTRK1 or BRAF rearrangement) were classified as high grade. By immunohistochemistry, S100 and CD34 positivity was noted in 71% and 60%, frequently in MPNST-like and LPFNT-like phenotypes. Pan-TRK was a sensitive marker for NTRK-translocated tumors but was negative in tumor with other kinase fusions. One patient with a high-grade tumor developed distant metastasis. Molecular testing for various kinase fusions should be considered for S100+/CD34+ spindle cell neoplasms with perivascular hyalinization and staghorn vessels, as pan-TRK positivity is seen only in NTRK fusions.

Efficacy and safety of sintilimab plus doxorubicin in advanced soft tissue sarcoma: A single-arm, phase II trial

Background: Chemoimmunotherapy is safe and efficacious in treating many types of malignant tumors. However, clinical data demonstrating the effect of this combination treatment in patients with metastatic soft tissue sarcoma (STS) are currently limited. This study evaluated the safety and efficacy of a programmed cell death protein 1 (PD-1) inhibitor plus doxorubicin in patients with advanced STS who failed previous systemic therapy. Methods: This was a single-center, single-arm, open-label phase II trial. Patients with unresectable or metastatic STS who had previously failed systemic therapy were enrolled. Patients received up to six cycles of doxorubicin and sintilimab (a PD-1 inhibitor), while sintilimab treatment continued for up to 2 years. Primary outcomes were objective response rate (ORR) and safety. Univariate Cox proportional hazards model was used to analyze the relationship between clinicopathological parameters and progression-free survival (PFS). Results: A total of 38 patients (20 men and 18 women) were enrolled in this study. The overall ORR was 39.5%, disease control rate was 71.1%, and the median PFS was 4.5 months [95% confidence interval (CI), 3.0-8.5 months]. The adverse events (AEs) associated with the combined treatment were mild, manageable, and well-tolerated. The most common grade 3 or higher AEs were hematologic, including leukopenia (21.1%), anemia (18.4%), and thrombocytopenia (18.4%). Patients with undifferentiated pleomorphic sarcoma (UPS) or dedifferentiated liposarcoma had a significantly longer PFS than those with other pathological subtypes [hazard ratio (HR) = 0.42, 95% CI 0.21-0.83; p = 0.013]. There was no significant difference in the median PFS between patients who had previously received anthracycline-based chemotherapy and those who had not (HR = 0.74, 95% CI 0.34-1.58, p = 0.43). Conclusion: Sintilimab plus doxorubicin is a safe and promising treatment for patients with advanced STS who have failed previous systemic therapy (including anthracycline-based chemotherapy). The efficacy of this combination therapy in UPS and dedifferentiated liposarcoma is superior to that in other sarcomas. Clinical Trial Registration: https://www.chictr.org.cn, registration number: ChiCTR1900027009.

Effectiveness and Tolerability of Anlotinib Plus PD-1 Inhibitors for Patients with Previously Treated Metastatic Soft-Tissue Sarcoma

Objective

This study was to investigate the effectiveness and tolerability of anlotinib plus PD-1 inhibitors for patients with previously treated metastatic soft tissue sarcoma (STS).

Methods

Patients with previously treated metastatic STS who were administered with anlotinib plus PD-1 inhibitors in clinical practice were included for analysis retrospectively. All the common subtypes of advanced STS were appropriate for analysis. Efficacy of the regimen was assessed according to the change of target lesion radiologically, and all the patients were followed up regularly. Safety profile during the combination administration was recorded and documented specifically. Clinical significance according to different STS subtypes was analyzed accordingly.

Results

From September 2018 to January 2022, a total of 32 patients with previously treated metastatic STS who received anlotinib plus PD-1 blockades were screened for the analysis in this study. The best overall response during the combination administration indicated that partial response was observed in 11 patients, stable disease was noted in 16 patients and progressive disease was found in 6 patients, yielding an objective response rate (ORR) of 34.4% (95% CI: 18.6–53.2%) and a disease control rate (DCR) of 84.4% (95% CI: 67.2–94.7%). Furthermore, the median PFS of 32 patients with metastatic STS was 7.6 months (95% CI: 3.31–11.89) and the median OS was 14.9 months (95% CI: 8.36–21.44). Besides, adverse reactions related to the treatment during anlotinib plus PD-1 inhibitors administration were observed in 29 patients (90.6%), of whom, a total of 13 patients (40.6%) were deemed as grade 3–4 adverse reactions and no grade 5 adverse reaction was found. Specifically, the most common adverse reactions were fatigue, hypertension, hand-foot syndrome, diarrhea and dermal toxicity.

Conclusion

Anlotinib plus PD-1 inhibitors demonstrated durable and promising efficacy and tolerable safety for patients with metastatic STS in real world. Further prospective clinical trials were warranted to validate the feasibility of anlotinib plus PD-1 blockades clinically.

Locally advanced undifferentiated small round cell sarcoma of the lung with novel SDCCAG8-AKT3 fusion and type II tumor immunity in the microenvironment: a rare case report

BACKGROUND

Despite significant recent advances in characterizing the molecular pathogenesis of undifferentiated small round cell sarcoma (USRCS), rare cases without reported gene alterations remain unclassified. To date, the efficacy and prognostic biomarker of immunotherapy in the treatment of unresectable USRCS has not been demonstrated, especially when these cases occurring in uncommon thoracic visceral organs with a novel gene fusion.

CASE DESCRIPTION

We report a case of locally advanced and unresectable USRCS of the lung (cT4N1M0) with SDCCAG8-AKT3 fusion identified by RNA-based next-generation sequencing (NGS). He initially admitted to our hospital chiefly complained of cough and dyspnea without any intervention. Imaging examinations, positron emission tomography/computed tomography (PET/CT), tumor biopsy, and a series of molecular tests based on tumor specimens were conducted for diagnosis. The molecular tests supplied more information delineating the case's molecular characteristics including PMS2 mutation, CD274 amplification, high tumor mutational burden (TMB-H), and high microsatellite instability (MSI-H). Multiple immunofluorescence (mIF) staining further revealed a specific immune-microenvironment phenotype with a 100% programmed death ligand 1 (PD-L1) expression and type II tumor immunity in the microenvironment (type II TIME) of this case. This 31-year-old non-smoking male received vincristine sulfate, dactinomycin, and cyclophosphamide (VAC) regimen chemotherapy combined with pembrolizumab and sequential radiotherapy. He had maintained a partial response (PR) according to response evaluation criteria in solid tumors (RECIST) 1.1 and a good quality of life for almost 14 months except for mild loss of appetite and hair loss after chemotherapy to the latest follow-up date.

CONCLUSIONS

Our study showed a rare case of lung USRCS harboring a novel SDCCAG8-AKT3 fusion. And we indicated that a comprehensive treatment including the combination of systemic VAC chemotherapy and anti-programmed cell death protein 1 (PD-1) immunotherapy, and sequential radiotherapy could be considered for similar cases, prophylactic managements of chemotherapy-related myelosuppression and urotoxicity should be administrated along with chemotherapy as well. Tumor immune microenvironment analysis and gene sequencing are recommended to obtain more prognostic biomarkers in addition to routine pathologic examinations in diagnosis and treatment of USRCS.