Precision medicine in Ewing sarcoma: a translational point of view

Enhanced Antipediatric Sarcoma Effect of Everolimus with Secukinumab by Targeting IL17A

In this study, we explored the therapeutic potential of everolimus, an mTOR inhibitor, in a patient-derived xenograft (PDX) of rhabdomyosarcoma, the most prevalent malignant pediatric sarcoma. In addition, rhabdoid tumor cell line A-204 and Ewings sarcoma cell line A-673 were cultured to assess the in vitro effect of everolimus. Furthermore, the cell-derived xenograft (CDX) of A-673 was established and treated with everolimus in vivo. IHC and Western blotting were performed to detect the expressions of pertinent proteins. Results showed that everolimus intervention had limited inhibitory effect on PDX tumor growth compared with cyclophosphamide. Nevertheless, everolimus treatment significantly influenced the phosphorylation levels of S6 kinase beta 1 (S6K1) and eIF4E-binding protein 1 (p-4E-BP1), resulting in the inhibition of angiogenesis in vitro and in vivo. Interestingly, everolimus led to an upregulation in the level of IL17A in sarcoma cells. Notably, when secukinumab, a mAb of IL17A, was combined with everolimus, it synergistically enhanced the inhibitory effect of everolimus on sarcoma cell proliferation in vitro and on the growth of PDX or CDX xenograft tumors in vivo. Importantly, this combination therapy did not affect the mTOR signaling. These results indicate that everolimus exerts an antipediatric sarcoma effect by inhibiting mTOR signal. However, everolimus induces sarcoma cells to produce IL17A, which promotes tumor cell survival and counteracts its antipediatric sarcoma effect. The combination of secukinumab effectively eliminates the effects of IL17A, thereby improving the therapeutic efficacy of everolimus in the context of pediatric sarcomas.

Current Approach to Undifferentiated Neoplasms, With Focus on New Developments and Novel Immunohistochemical Stains

CONTEXT.—

Workup of the poorly differentiated or undifferentiated tumor remains a significant and challenging entity in the practice of anatomic pathology. Particularly in the setting of small biopsies and limited material, these cases demand a balanced approach that considers the patient's clinical and radiologic presentation, a basic assessment of tumor morphology, a reasonably broad immunohistochemical panel, and diligent preservation of tissue for prognostic and therapeutic studies.

OBJECTIVE.—

To illustrate some of the new and emerging immunohistochemical markers in the evaluation of tumors with undifferentiated or poorly differentiated morphology, with a focus on the workup in limited tissue samples to raise awareness of the issues involved with the pathologic workup in these challenging tumors.

DATA SOURCES.—

A literature review of new ancillary studies that can be applied to cytologic specimens was performed.

CONCLUSIONS.—

Knowledge of the patient's history and communication with the patient's clinical team is essential in formulating a differential diagnosis that can appropriately limit the differential diagnosis based on morphology, especially in small specimens. This information, in conjunction with classifying the tumor morphology (eg, epithelioid, spindled, neuroendocrine, basaloid/biphasic, mixed) gives a logical approach to choosing an initial immunohistochemical panel. Fortunately, immunohistochemistry is evolving quickly in the wake of groundbreaking molecular studies to develop new and better markers to further classify these difficult tumors beyond where we traditionally have been able to go.

EWS/FLI1 Characterization, Activation, Repression, Target Genes and Therapeutic Opportunities in Ewing Sarcoma

Despite their clonal origins, tumors eventually develop into complex communities made up of phenotypically different cell subpopulations, according to mounting evidence. Tumor cell-intrinsic programming and signals from geographically and temporally changing microenvironments both contribute to this variability. Furthermore, the mutational load is typically lacking in childhood malignancies of adult cancers, and they still exhibit high cellular heterogeneity levels largely mediated by epigenetic mechanisms. Ewing sarcomas represent highly aggressive malignancies affecting both bone and soft tissue, primarily afflicting adolescents. Unfortunately, the outlook for patients facing relapsed or metastatic disease is grim. These tumors are primarily fueled by a distinctive fusion event involving an FET protein and an ETS family transcription factor, with the most prevalent fusion being EWS/FLI1. Despite originating from a common driver mutation, Ewing sarcoma cells display significant variations in transcriptional activity, both within and among tumors. Recent research has pinpointed distinct fusion protein activities as a principal source of this heterogeneity, resulting in markedly diverse cellular phenotypes. In this review, we aim to characterize the role of the EWS/FLI fusion protein in Ewing sarcoma by exploring its general mechanism of activation and elucidating its implications for tumor heterogeneity. Additionally, we delve into potential therapeutic opportunities to target this aberrant fusion protein in the context of Ewing sarcoma treatment.

Downregulated annexin A1 expression correlates with poor prognosis, metastasis, and immunosuppressive microenvironment in Ewing's sarcoma

OBJECTIVE

Ewing's sarcoma (ES) is a common bone malignancy in children and adolescents that severely affects the prognosis of patients. The aim of this study was to identify novel biomarkers and potential therapeutic targets for ES.

METHODS

Highly prognosis-related hub genes were identified by independent prognostic analysis in the GSE17679 dataset. We then performed survival analysis, Cox regression analysis and clinical correlation analysis on the key gene and validated them with the GSE63157, GSE45544 and GSE73166 datasets. Differentially expressed genes (DEGs) were screened based on the high and low expression of key gene, Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses, Gene Set Enrichment Analysis (GSEA), and Gene Set Variation Analysis (GSVA) were performed to explore the underlying mechanisms of ES, and significant module genes were established based on protein-protein interaction (PPI) networks. Furthermore, the correlations between module genes and the immune microenvironment were analyzed and the correlations between the key gene and immune infiltration levels in sarcoma were investigated using TIMER and TISIDB. Finally, the expression levels of these key genes in ES cell lines (RD-ES and A673 cells) were further validated by real-time quantitative PCR (RT-qPCR). CCK-8 and EdU assays were performed to assess the effect of ANXA1 knockdown on RD-ES cell proliferation.

RESULTS

ANXA1 was identified as a key gene for ES prognosis. The overall survival (OS) time of patients with low ANXA1 expression was shorter, and the expression level of ANXA1 in the metastatic group was significantly lower than that in the primary group (P<0.01). Additionally, the abundance of 12 immune cells in the ANXA1 low-expression group was significantly lower than that in the high-expression group (all P<0.05), which may be related to the inhibition of the immune microenvironment. A PPI network was constructed based on 96 DEGs to further identify the five ANXA1-related module genes (COL1A2, MMP9, VIM, S100A11 and S100A4). The expression levels of ANXA1, COL1A2, MMP9, VIM, S100A11 and S100A4 were significantly different between ES cell lines and mesenchymal stem cells after validation in two ES cell lines (all P<0.01). Among these genes, ANXA1, COL1A2, MMP9, VIM and S100A4 were significantly associated with the prognosis of ES patients (all P<0.05). Importantly, ANXA1 knockdown significantly promoted the proliferation of RD-ES cells, which may explain the susceptibility to ES metastasis in the ANXA1 low-expression group.

CONCLUSIONS

ANXA1 may serve as an independent prognostic biomarker for ES patients and is associated with metastasis and the immunosuppressive microenvironment in ES, which needs to be validated in further studies.

Management of Unresectable Localized Pelvic Bone Sarcomas: Current Practice and Future Perspectives

Simple Summary

Some locally advanced pelvic bone tumors are deemed unresectable and, as such, not suitable for curative surgery. In this setting, treatment options are generally limited and not unanimous, with decisions being made on an individual basis after multidisciplinary discussion. Ultimately, and notwithstanding the bright prospects raised by novel therapeutic approaches, treatment should be patient-tailored, weighing a panoply of patient- and tumor-related factors.

Abstract

Bone sarcomas (BS) are rare mesenchymal tumors usually located in the extremities and pelvis. While surgical resection is the cornerstone of curative treatment, some locally advanced tumors are deemed unresectable and hence not suitable for curative intent. This is often true for pelvic sarcoma due to anatomic complexity and proximity to vital structures, making treatment options for these tumors generally limited and not unanimous, with decisions being made on an individual basis after multidisciplinary discussion. Several studies have been published in recent years focusing on innovative treatment options for patients with locally advanced sarcoma not amenable to local surgery. The present article reviews the evidence regarding the treatment of patients with locally advanced and unresectable pelvic BS, with the goal of providing an overview of treatment options for the main BS histologic subtypes involving this anatomic area and exploring future therapeutic perspectives. The management of unresectable localized pelvic BS represents a major challenge and is hampered by the lack of comprehensive and standardized guidelines. As such, the optimal treatment needs to be individually tailored, weighing a panoply of patient- and tumor-related factors. Despite the bright prospects raised by novel therapeutic approaches, the role of each treatment option in the therapeutic armamentarium of these patients requires solid clinical evidence before becoming fully established.

Trends in Tumor Site-Specific Survival of Bone Sarcomas from 1980 to 2018: A Surveillance, Epidemiology and End Results-Based Study

OBJECTIVES

As diagnosis and treatment guidelines for bone sarcomas continue updating, it is important to examine whether, when, and which kinds of patients have had a survival improvement over the last four decades.

METHODS

This cohort study included 9178 patients with primary bone and joint sarcomas from 1 January 1980 to 31 December 2018 using data from Surveillance, Epidemiology and End Results (SEER)-9 Registries. The follow-up period was extended to November 2020. Patients were divided by decade into four time periods: 1980-1989, 1990-1999, 2000-2009, and 2010-2018. The primary endpoint was bone sarcomas-specific mortality (CSM). The 5-year bone sarcomas-specific survival (CSS) rate was determined stratified by demographic, neoplastic, temporal, economic, and geographic categories. The associations between time periods and CSM were examined using a multivariable Cox regression model, with reported hazard ratio (HR) and 95% confidence interval (CI).

RESULTS

The 5-year CSS rate for bone sarcomas was 58.7%, 69.9%, 71.0%, and 69.2%, in the 1980s, 1990s, 2000s, and 2010s, respectively. Older age, male gender, tumor sites at pelvic bones, sacrum, coccyx and associated joints, as well as vertebral column, osteosarcoma and Ewing tumor, and residence in non-metropolitan areas were independently associated with higher CSM risk. After adjusting for the covariates above, patients in the 1990s (HR = 0.74, 95% CI = 0.68-0.82), 2000s (HR = 0.71, 95% CI = 0.65-0.78), and 2010s (HR = 0.68, 95% CI = 0.62-0.76) had significantly lower CSM risks than patients in the 1980s. However, patients in the 2000s and 2010s did not have lower CSM risks than those in the 1990s (both p > 0.05).

CONCLUSIONS

Although bone sarcomas survival has significantly improved since 1990, it almost halted over the next three decades. Bone sarcomas survival should improve over time, similar to common cancers. New diagnostic and therapeutic strategies such as emerging immune and targeted agents are warranted to overcome this survival stalemate.

Childhood Cancer: Occurrence, Treatment and Risk of Second Primary Malignancies

Cancer represents the leading cause of disease-related death and treatment-associated morbidity in children with an increasing trend in recent decades worldwide. Nevertheless, the 5-year survival of childhood cancer patients has been raised impressively to more than 80% during the past decades, primarily attributed to improved diagnostic technologies and multiagent cytotoxic regimens. This strong benefit of more efficient tumor control and prolonged survival is compromised by an increased risk of adverse and fatal late sequelae. Long-term survivors of pediatric tumors are at the utmost risk for non-carcinogenic late effects such as cardiomyopathies, neurotoxicity, or pneumopathies, as well as the development of secondary primary malignancies as the most detrimental consequence of genotoxic chemo- and radiotherapy. Promising approaches to reducing the risk of adverse late effects in childhood cancer survivors include high precision irradiation techniques like proton radiotherapy or non-genotoxic targeted therapies and immune-based treatments. However, to date, these therapies are rarely used to treat pediatric cancer patients and survival rates, as well as incidences of late effects, have changed little over the past two decades in this population. Here we provide an overview of the epidemiology and etiology of childhood cancers, current developments for their treatment, and therapy-related adverse late health consequences with a special focus on second primary malignancies.

Next-Generation Sequencing Identifies Potential Actionable Targets in Paediatric Sarcomas

Background: Bone and soft-tissue sarcomas represent 13% of all paediatric malignancies. International contributions to introduce next-generation sequencing (NGS) approaches into clinical application are currently developing. We present the results from the Precision Medicine program for children with sarcomas at a reference centre. Results: Samples of 70 paediatric sarcomas were processed for histopathological analysis, reverse transcriptase polymerase chain reaction (RT-PCR) and next-generation sequencing (NGS) with a consensus gene panel. Pathogenic alterations were reported and, if existing, targeted recommendations were translated to the clinic. Seventy paediatric patients with sarcomas from 10 centres were studied. Median age was 11.5 years (range 1–18). Twenty-two (31%) had at least one pathogenic alteration by NGS. Thirty pathogenic mutations in 18 different genes were detected amongst the 22 patients. The most frequent alterations were found in TP53, followed by FGFR4 and CTNNB1. Combining all biological studies, 18 actionable variants were detected and six patients received targeted treatment observing a disease control rate of 78%. Extrapolating the results to the whole cohort, 23% of the patients would obtain clinical benefit from this approach. Conclusions: Paediatric sarcomas have a different genomic landscape when compared to adult cohorts. Incorporating NGS targets into paediatric sarcomas’ therapy is feasible and allows personalized treatments with clinical benefit in the relapse setting.

Sarcoma treatment in the era of molecular medicine

Sarcomas are heterogeneous and clinically challenging soft tissue and bone cancers. Although constituting only 1% of all human malignancies, sarcomas represent the second most common type of solid tumors in children and adolescents and comprise an important group of secondary malignancies. More than 100 histological subtypes have been characterized to date, and many more are being discovered due to molecular profiling. Owing to their mostly aggressive biological behavior, relative rarity, and occurrence at virtually every anatomical site, many sarcoma subtypes are in particular difficult-to-treat categories. Current multimodal treatment concepts combine surgery, polychemotherapy (with/without local hyperthermia), irradiation, immunotherapy, and/or targeted therapeutics. Recent scientific advancements have enabled a more precise molecular characterization of sarcoma subtypes and revealed novel therapeutic targets and prognostic/predictive biomarkers. This review aims at providing a comprehensive overview of the latest advances in the molecular biology of sarcomas and their effects on clinical oncology; it is meant for a broad readership ranging from novices to experts in the field of sarcoma.

Dienone Compounds: Targets and Pharmacological Responses

The biological responses to dienone compounds with a 1,5-diaryl-3-oxo-1,4-pentadienyl pharmacophore have been studied extensively. Despite their expected general thiol reactivity, these compounds display considerable degrees of tumor cell selectivity. Here we review in vitro and preclinical studies of dienone compounds including b-AP15, VLX1570, RA-9, RA-190, EF24, HO-3867, and MCB-613. A common property of these compounds is their targeting of the ubiquitin–proteasome system (UPS), known to be essential for the viability of tumor cells. Gene expression profiling experiments have shown induction of responses characteristic of UPS inhibition, and experiments using cellular reporter proteins have shown that proteasome inhibition is associated with cell death. Other mechanisms of action such as reactivation of mutant p53, stimulation of steroid receptor coactivators, and induction of protein cross-linking have also been described. Although unsuitable as biological probes due to widespread reactivity, dienone compounds are cytotoxic to apoptosis-resistant tumor cells and show activity in animal tumor models.

Management of Refractory Pediatric Sarcoma: Current Challenges and Future Prospects

Paediatric sarcomas are a heterogeneous group of disorders constituting bone sarcoma and various soft tissue sarcomas. Almost one-third of these presents with metastasis at baseline and another one-third recur after initial curative treatment. There is a huge unmet need in this cohort in terms of curative options and/or prolongation of survival. In this review, we have discussed the current treatment options, challenges and future strategies of managing relapsed/refractory paediatric sarcomas. Upfront risk-adapted treatment with multidisciplinary management remains the main strategy to prevent future recurrence or relapse of the disease. In the case of limited local and/or systemic relapse or late relapse, initial multimodality management can be administered. In treatment-refractory cases or where cure is not feasible, the treatment options are limited to novel therapeutics, immunotherapeutic approach, targeted therapies, and metronomic therapies. A better understanding of disease biology, mechanism of treatment refractoriness, identifications of driver mutation, the discovery of novel targeted therapies, cellular vaccine and adapted therapies should be explored in relapsed/refractory cases. Close national and international collaboration for translation research is needed to fulfil the unmet need.