Cabozantinib and dastinib exert anti-tumor activity in alveolar soft part sarcoma

Imaging Features of Alveolar Soft Part Sarcoma: Single Institution Experience and Literature Review

Alveolar soft part sarcoma (ASPS) is an extremely rare and aggressive soft-tissue sarcoma (STS) subtype with poor prognosis and limited response to radiation therapy and chemotherapy. Prompt recognition and referral to sarcoma centers for appropriate management are crucial for patients' survival. The purpose of this study was to report ASPS pre-treatment imaging features and to examine the existing literature on this topic. Twelve patients (7 women, 5 men-mean age 27.1 ± 10.7 years) were included from our single-center experience. Ultrasonography (US), computed tomography (CT), and magnetic resonance imaging (MRI) available were reviewed according to an analysis grid incorporating features from the latest research on STS. Clinical, histological, and outcome data were collected. MRI was available in 10 patients (83.3%), US in 7 patients (58.3%), and CT in 3 patients (25%). Mean longest tumor diameter was 7.6 ± 2.9 cm, and all tumors were deeply seated. Large peritumoral feeding vessels were systematically found and identified on ultrasonography (7/7), MRI (10/10), and CT (3/3). US revealed a well-defined heterogeneous hypoechoic pattern, with abundant flow signals in all patients (7/7). In all patients, MRI showed mildly high signal intensity (SI) on T1-WI and high SI on T2-WI and peritumoral edema. Moreover, flow-voids (due to arteriosus high-flow) into the peritumoral/intratumoral feeding vessels were detected in the MRI fluid-sensitive sequences of all patients. At baseline, whole-body contrast-enhanced CT revealed metastases in 8/12 (66.7%) patients. A pre-treatment longest diameter > 5 cm was significantly associated with distant metastases at diagnosis (p = 0.01). A maximum diameter > 5 cm represents a risk of metastatic disease at diagnosis (odds ratio = 45.0000 (95% CI: 1.4908-1358.3585), p = 0.0285). In the comprehensive literature review, we found 14 articles (case series or original research) focusing on ASPS imaging, with a total of 151 patients included. Merging our experience with the data from the existing literature, we conclude that the hallmark of ASPS imaging at presentation are the following characteristics: deep location, a slight hyperintense MRI SI on T1-WI and a hyperintense SI on T2-WI, numerous MRI flow voids, high internal vascularization, and large peritumoral feeding vessels.

Comprehensive genomic analysis of primary bone sarcomas reveals different genetic patterns compared with soft tissue sarcomas

Introduction

Sarcomas are classified into two types, bone sarcoma and soft tissue sarcoma (STS), which account for approximately 1% of adult solid malignancies and 20% of pediatric solid malignancies. There exist more than 50 subtypes within the two types of sarcoma. Each subtype is highly diverse and characterized by significant variations in morphology and phenotypes. Understanding tumor molecular genetics is helpful in improving the diagnostic accuracy of tumors that have been difficult to classify based on morphology alone or that have overlapping morphological features. The different molecular characteristics of bone sarcoma and STS in China remain poorly understood. Therefore, this study aimed to analyze genomic landscapes and actionable genomic alterations (GAs) as well as tumor mutational burden (TMB), microsatellite instability (MSI), and programmed death ligand-1 (PD-L1) expression among Chinese individuals diagnosed with primary bone sarcomas and STS.

Methods

This retrospective study included 145 patients with primary bone sarcomas (n = 75) and STS (n = 70), who were categorized based on the 2020 World Health Organization classification system.

Results

Patients diagnosed with bone sarcomas were significantly younger than those diagnosed with STS (p < 0.01). The top 10 frequently altered genes in bone sarcoma and STS were TP53, CDKN2A, CDKN2B, MAP3K1, LRP1B, MDM2, RB1, PTEN, MYC, and CDK4.The EWSR1 fusions exhibited statistically significant differences (p < 0.01) between primary bone sarcoma and STS in terms of their altered genes. Based on the actionable genes defined by OncoKB, actionable GAs was found in 30.7% (23/75) of the patients with bone sarcomas and 35.7% (25/70) of those with STS. There were 4.0% (3/75) patients with bone sarcoma and 4.3% (3/70) patients with STS exhibited high tumor mutational burden (TMB-H) (TMB ≥ 10). There was only one patient with STS exhibited MSI-L, while the remaining cases were microsatellite stable. The positive rate of PD-L1 expression was slightly higher in STS (35.2%) than in bone sarcoma (33.3%), however, this difference did not reach statistical significance. The expression of PD-L1 in STS patients was associated with a poorer prognosis (p = 0.007). Patients with STS had a better prognosis than those with bone sarcoma, but the observed difference did not attain statistical significance (p = 0.21). Amplification of MET and MYC genes were negatively correlated with clinical prognosis in bone tumors (p<0.01).

Discussion

In conclusion, bone sarcoma and STS have significantly different clinical and molecular characteristics, suggesting that it is vital to diagnose accurately for clinical treatment. Additionally, comprehensive genetic landscape can provide novel treatment perspectives for primary bone sarcoma and STS. Taking TMB, MSI, PD-L1 expression, and OncoKB definition together into consideration, there are still many patients who have the potential to respond to targeted therapy or immunotherapy.

The Recent Advances in Molecular Diagnosis of Soft Tissue Tumors

Soft tissue tumors are rare mesenchymal tumors with divergent differentiation. The diagnosis of soft tissue tumors is challenging for pathologists owing to the diversity of tumor types and histological overlap among the tumor entities. Present-day understanding of the molecular pathogenesis of soft tissue tumors has rapidly increased with the development of molecular genetic techniques (e.g., next-generation sequencing). Additionally, immunohistochemical markers that serve as surrogate markers for recurrent translocations in soft tissue tumors have been developed. This review aims to provide an update on recently described molecular findings and relevant novel immunohistochemical markers in selected soft tissue tumors.

Genetic Alterations and Deregulation of Hippo Pathway as a Pathogenetic Mechanism in Bone and Soft Tissue Sarcoma

The Hippo pathway is an evolutionarily conserved modulator of developmental biology with a key role in tissue and organ size regulation under homeostatic conditions. Like other signaling pathways with a significant role in embryonic development, the deregulation of Hippo signaling contributes to oncogenesis. Central to the Hippo pathway is a conserved cascade of adaptor proteins and inhibitory kinases that converge and regulate the activity of the oncoproteins YAP and TAZ, the final transducers of the pathway. Elevated levels and aberrant activation of YAP and TAZ have been described in many cancers. Though most of the studies describe their pervasive activation in epithelial neoplasms, there is increasing evidence pointing out its relevance in mesenchymal malignancies as well. Interestingly, somatic or germline mutations in genes of the Hippo pathway are scarce compared to other signaling pathways that are frequently disrupted in cancer. However, in the case of sarcomas, several examples of genetic alteration of Hippo members, including gene fusions, have been described during the last few years. Here, we review the current knowledge of Hippo pathway implication in sarcoma, describing mechanistic hints recently reported in specific histological entities and how these alterations represent an opportunity for targeted therapy in this heterogeneous group of neoplasm.

Metastatic mesenchymal chondrosarcoma showing a sustained response to cabozantinib: A case report

Mesenchymal chondrosarcoma is a rare and aggressive sarcoma subtype with high risk for distant metastases and poor prognosis. Currently NCCN- and ESMO-Guidelines recommend using Ewing sarcoma protocols as standard treatment. Nevertheless, in localized disease overall 5-year survival rates are below 50% whereas in metastatic spread median progression-free survival rates of only 5 months can be expected. Here we present a patient with metastatic osseous spread of mesenchymal chondrosarcoma that showed a sustained clinical improvement and a good partial response on imaging over a period of one year when treated with the multi-tyrosine kinase inhibitor cabozantinib. Although we cannot explain the exact mechanism underlying this treatment effect, tumors with similar genetic patterns might respond to the same therapy as well.

Anti-cancer activity of the combination of cabozantinib and temozolomide in uterine sarcoma

PURPOSE

To evaluate the anti-cancer effects of cabozantinib, temozolomide, and their combination in uterine sarcoma cell lines and mouse xenograft models.

EXPERIMENTAL DESIGN

Human uterine sarcoma cell lines (SK-LMS-1, SK-UT-1, MES-SA, and SKN) were used to evaluate the anti-cancer activity of cabozantinib, temozolomide, and their combination. The optimal dose of each drug was determined by MTT assay. Cell proliferation and apoptosis were assessed 48 hours and 72 hours after the drug treatments. The tumor weights were measured in an SK-LMS-1 xenograft mouse model and a patient-derived xenograft (PDX) model of leiomyosarcoma treated with cabozantinib, temozolomide, or both.

RESULTS

Given individually, cabozantinib and temozolomide each significantly decreased the growth and viability of cells. This inhibitory effect was more pronounced when cabozantinib (0.50 µM) and temozolomide (0.25 mM or 0.50 mM) were co-administered (p-value < 0.05). The combination of the drugs also significantly increased apoptosis in all cells. Moreover, this effect was consistently observed in patient-derived leiomyosarcoma cells. In vivo studies with SK-LMS-1 cell xenografts and the PDX model with leiomyosarcoma demonstrated that combined treatment with cabozantinib (5 mg/kg/day, per os administration) and temozolomide (5 mg/kg/day, per os administration) synergistically decreased tumor growth (both p-values < 0.05).

CONCLUSION

The addition of cabozantinib to temozolomide offers synergistic anti-cancer effects in uterine sarcoma cell lines and xenograft mouse models, including PDX. These results warrant further investigation in a clinical trial.

Synthesis of new thienylnicotinamidines: Proapoptotic profile and cell cycle arrest of HepG2 cells

Fourteen new thienylnicotinamidines and their analogs 5a-5k, 12, 13a, and 13b were prepared and their antiproliferative potential was evaluated against the growth of 60 cancer cell lines. The tested compounds had a strong antiproliferative efficacy against almost all cancer cell lines, with the average GI₅₀ at ~2.20 µM. The effect of the thienylnicotinamidines on the growth of normal lung fibroblast cells (WI-38) indicated that these derivatives are safe to the normal cells. The selectivity index (SI) ranges from 5.5- to 42.0-fold. The conceivable mechanisms of action of the effective compounds 5d, 5f, 5g, 5i, 5j, and 5k with high SI were investigated. Although the thienylnicotinamidines are similar in structure, they could be divided into three groups as per their effects on gene expression: The first group (5d and 5f) elevated p53 and caspase 3 expression, the second group (5g and 5i) elevated p53 expression, and the last group (5j and 5k) elevated p53 and reduced topoII expression. Many thienylnicotinamides inhibited the vascular endothelial growth factor receptor-2 (VEGFR-2) in cell lysates at concentrations comparable to or better than pazopanib. The data of caspase 3 expression were confirmed by measuring the protein level by Western blot and the activity of the cleaved active enzyme. The ability to arrest the cell cycle and induce apoptosis was confirmed by flow cytometry. Taken together, two derivatives, 5d and 5f, with a distinctive VEGFR-2 inhibitory activity and a proapoptotic and cell cycle arrest profile merit further investigations.

Targeting the FAK-Src Complex in Desmoplastic Small Round Cell Tumors, Ewing Sarcoma, and Rhabdomyosarcoma

Desmoplastic small round cell tumors (DSRCTs), Ewing sarcoma (ES), and alveolar and embryonal rhabdomyosarcoma (ARMS and ERMS) are malignant sarcomas typically occurring at young age, with a poor prognosis in the metastatic setting. New treatment options are necessary. Src family kinase inhibitor dasatinib single-agent treatment has been investigated in a phase 2 study in patients with advanced sarcomas including ES and RMS but failed as a single agent in these subtypes. Since previous studies demonstrated high FAK and Src activities in RMS and ES tissue and cell lines, and dasatinib treatment was shown to upregulate activated FAK, we hypothesized that FAK-Src combination treatment could potentially be an interesting treatment option for these tumor types. We examined the effects of targeting the FAK-Src complex by addressing (p)FAK and (p)Src expressions in tumor sections of DSRCT (n = 13), ES (n = 68), ARMS (n = 21), and ERMS (n = 39) and by determining the antitumor effects of single and combined treatment with FAK inhibitor defactinib and multikinase (Abl/SFK) inhibitor dasatinib in vitro on cell lines of each subtype. In vivo effects were assessed in DSRCT and ERMS models. Concurrent pFAK and pSrc expressions (H-score >50) were observed in DSRCT (67%), ES (6%), ARMS (35%), and ERMS (19%) samples. Defactinib treatment decreased pFAK expression and reduced cell viability in all subtypes. Dasatinib treatment decreased pSrc expression and cell viability in each subtype. Combination treatment led to a complete reduction in pFAK and pSrc in each cell line and showed enhanced cell viability reduction, drug synergy, DNA damage induction, and a trend toward higher apoptosis induction in DSRCT, ERMS, and ARMS but not in ES cells. These promising in vitro results unfortunately do not translate into promising in vivo results as we did not observe a significant effect on tumor volume in vivo, and the combination did not show superior effects compared to dasatinib single-agent treatment.

Clinical Activity of Single-Agent Cabozantinib (XL184), a Multi-receptor Tyrosine Kinase Inhibitor, in Patients with Refractory Soft-Tissue Sarcomas

PURPOSE

Soft-tissue sarcomas (STS) are a rare, heterogeneous group of mesenchymal tumors. For decades the mainstay of treatment for advanced, unresectable STS has been palliative chemotherapy. High levels of activated MET receptor have been reported in various sarcoma cell lines, together with elevated vascular endothelial growth factor (VEGF) levels in patients with STS, suggesting that dual targeting of the VEGF and MET pathways with the multi-receptor tyrosine kinase inhibitor cabozantinib would result in clinical benefit in this population.

PATIENTS AND METHODS

We performed an open-label, multi-institution, single-arm phase II trial of single-agent cabozantinib in adult patients with advanced STS and progressive disease after at least 1 standard line of systemic therapy. Patients received 60 mg oral cabozantinib once daily in 28-day cycles, and dual primary endpoints of overall response rate and 6-month progression-free survival (PFS) were assessed. Changes in several circulating biomarkers were assessed as secondary endpoints.

RESULTS

Six (11.1%; 95% CI, 4.2%-22.6%) of the 54 evaluable patients enrolled experienced objective responses (all partial responses). Six-month PFS was 49.3% (95% CI, 36.2%-67.3%), with a median time on study of 4 cycles (range, 1-99). The most common grade 3/4 adverse events were hypertension (7.4%) and neutropenia (16.7%). Patients' levels of circulating hepatocyte growth factor (HGF), soluble MET, and VEGF-A generally increased after a cycle of therapy, while soluble VEGFR2 levels decreased, regardless of clinical outcome.

CONCLUSIONS

Cabozantinib single-agent antitumor activity was observed in patients with selected STS histologic subtypes (alveolar soft-part sarcoma, undifferentiated pleomorphic sarcoma, extraskeletal myxoid chondrosarcoma, and leiomyosarcoma) highlighting the biomolecular diversity of STS.

The current management of alveolar soft part sarcomas

OBJECTIVE

Alveolar soft part sarcomas (ASPS) which has high potential ability of metastasis, is a rare and slowly growing malignant tumor, and mainly primary localized in limbs. To date, little is known about the best treatment of ASPS. This study aims to review the current management and advance of ASPS.

METHODS

WANFANG MED ONLINE, CNKI, and NCBI PUBMED were used to search literature spanning from 1963 to 2020, and all cases of ASPS about "ASPS, diagnosis, treatment, surgery, radiotherapy, chemotherapy, target therapy or immune therapy" with detailed data were included.

RESULTS

Complete surgical resection remained the standard management strategy, radiotherapy was reported to be used for the patients of micro- or macroscopical incomplete residue or the surgical margin was questionable. Chemotherapy was controversial. Some target drugs and immune checkpoint inhibitors had produced antitumor activity.

CONCLUSION

Complete surgical resection is the cure treatment for ASPS, and adjuvant chemotherapy is not recommended excepted clinical trials. For the patients with micro- or macroscopical incomplete residue, radiotherapy should be appreciated. Furthermore, for recurrence, distant metastasis, and refractory of ASPS, combination therapy, especially combination with multiple target agents and/or immune checkpoint inhibitors may prolong survival time.

Cabozantinib as an emerging treatment for sarcoma

PURPOSE OF REVIEW

Sarcomas are a diverse group of rare solid tumors with limited treatment options for patients with advanced, inoperable disease. Cabozantinib is a tyrosine kinase inhibitor currently approved for advanced renal cell, hepatocellular, and medullary thyroid carcinoma. Cabozantinib has potent activity against a variety of kinases, including MET, vascular endothelial growth factor receptor, and AXL, that are associated with sarcoma growth and development. Here we review the preclinical findings and clinical development of cabozantinib in the treatment of soft tissue sarcoma, gastrointestinal stromal tumors (GIST), osteosarcoma, and Ewing sarcoma.

RECENT FINDINGS

In vitro, cabozantinib has shown relevant activity in inhibiting the growth and viability of soft tissue sarcoma, GIST, osteosarcoma, and Ewing sarcoma tumor cell lines. Cabozantinib also promoted the regression of GIST in various murine xenografts, including imatinib-resistant models. More than 10 prospective trials with cabozantinib that included patients with sarcomas have been completed or are currently ongoing. Clinical activity with cabozantinib has been recently reported in phase 2 clinical trials for patients with GIST and for patients with osteosarcoma or Ewing sarcoma.

SUMMARY

Cabozantinib has shown promising activity for the treatment of various sarcomas, supporting further evaluation in this setting.

Establishment and characterization of NCC-ASPS1-C1: a novel patient-derived cell line of alveolar soft-part sarcoma

Alveolar soft-part sarcoma is a mesenchymal malignancy characterized by the rearrangement of ASPSCR1 and TFE3 and a histologically distinctive pseudoalveolar pattern. Although alveolar soft-part sarcoma takes an indolent course, its long-term prognosis is poor because of late distant metastases. Currently, curative treatments have not been found for alveolar soft-part sarcoma, and hence, a novel therapeutic strategy has long been required. Patient-derived cell lines comprise an important tool for basic and preclinical research. However, few cell lines from alveolar soft-part sarcoma have been reported in the literature because it is an extremely rare malignancy, accounting for less than 1% of all soft-tissue sarcomas. This study aimed to establish a novel alveolar soft-part sarcoma cell line. Using surgically-resected tumor tissue of alveolar soft-part sarcoma, we successfully established a cell line and named it NCC-ASPS1-C1. The NCC-ASPS1-C1 cells harbored an ASPSCR1-TFE3 fusion gene and exhibited slow growth, and spheroid formation. On the other hand, NCC-ASPS1-C1 did not show the capability of invasion. We screened the antiproliferative effects of 195 anticancer agents, including Food and Drug Administration-approved anticancer drugs. We found that the MET inhibitor tivantinib and multi-kinase inhibitor orantinib inhibited the proliferation of NCC-ASPS1-C1 cells. The clinical utility and molecular mechanisms of antitumor effects of these drugs are worth investigating in the further studies, and NCC-ASPS1-C1 cells will be a useful tool for the in vitro study of alveolar soft-part sarcoma.

The landscape of tyrosine kinase inhibitors in sarcomas: looking beyond pazopanib

Introduction: Tyrosine kinases are key mediators of intracellular signaling cascades and aberrations in these proteins have been implicated in driving oncogenesis through the dysregulation of fundamental cellular processes including proliferation, migration, and apoptosis. As such, targeting these proteins with small molecule tyrosine kinase inhibitors (TKI) has led to significant advances in the treatment of a number of cancer types.Areas covered: Soft tissue sarcomas (STS) are a heterogeneous and challenging group of rare cancers to treat, but the approval of the TKI pazopanib for the treatment of advanced STS demonstrates that this class of drugs may have broad utility against a range of different sarcoma histological subtypes. Since the approval of pazopanib, a number of other TKIs have entered clinical trials to evaluate whether their activity in STS matches the promising results seen in other solid tumors. In this article, we review the emerging role of TKIs in the evolving landscape of sarcoma treatment.Expert opinion: As our biological understanding of response and resistance of STS to TKIs advances, we anticipate that patient management will move away from a 'one size fits all' paradigm toward personalized, multi-line, and patient-specific treatment regimens where patients are treated according to the underlying biology and genetics of their specific disease.