Molecular Targeted Therapy in the Treatment of Chordoma: A Systematic Review

Notochordal cell derived lesions: a 55-year casuistic analysis of 50 cases with radiologic-pathologic correlation in a tertiary referral hospital, and literature review

Distinct lesions are derived from notochordal cells (NCDL), ranging from benign to malignant ones. This study presents fifty NCDL cases diagnosed in a tertiary hospital of reference from the past 55 years: forty-two conventional chordomas, including one chondroid chordoma subtype, four benign notochordal cell tumors (BNCT), two conventional chordomas with BNCT foci, and two dedifferentiated chordomas. All patients were adults. Three BNCT were incidentally diagnosed, and one case presented local pain. Chordomas began with local pain and/or neurological symptoms. BNCT were well-defined intraosseous lesions, hypointense on T1-weighted images (WI) and hyperintense on T2-WI, without enhancement in the contrast. Conventional chordomas, including its chondroid subtype, were lobulated masses with cortical disruption and soft tissue extension, hypointense on T1-WI and hyperintense on T2-WI, with variable contrast enhancement. BNCT were histologically composed of solid sheets of vacuolated cells with clear cytoplasm and round and central nuclei. No atypia, lobular growth pattern, myxoid matrix, or bone infiltration were seen. Conventional chordomas were histologically composed of physaliphorous cells in a myxoid stroma with lobulated and infiltrating growth patterns. Observational follow-up using radiological controls was decided on for the BNCT cases. None of these cases presented local recurrence or metastasis. En-bloc resection and adjuvant radiotherapy were selected for sacral and vertebral chordoma cases. Sixteen patients died due to tumor-related factors; twenty-eight presented local recurrence, and four developed distant metastases. New therapeutic options are being studied for chordoma cases. Clinical, radiological, and histopathological data are necessary to properly diagnose and follow up of NCDL.

Hypoxia-Inducible Factor-1α (HIF-1α) as a Factor to Predict the Prognosis of Spinal Chordoma

STUDY DESIGN

Retrospective study.

OBJECTIVE

In this study, the authors explore the potential relationship between hypoxia inducible factor-1α (HIF-1α) and the prognosis of patients with spinal chordoma.

SUMMARY OF BACKGROUND DATA

Currently, prognostic factors related to the clinical course in the setting of spinal chordoma are poorly understood. Although the close relationship between HIF-1α and tumor angiogenesis, metastasis, and recurrence have been widely reported, it has not been investigated in the context of spinal chordoma.

MATERIALS AND METHODS

In this study, 32 samples of chordoma patients were compared with 14 nucleus pulposus tissues as controls. The specific expression of HIF-1α was detected by immunohistochemistry. Continuous disease-free survival (CDFS) was defined as the interval from tumor resection to confirmation of the first local recurrence or distant metastasis. Overall survival (OS) was defined as the interval from the date of surgery to death related to any cause. The relationship between HIF-1α expression and the clinicopathologic characteristics of patients with chordoma was analyzed using the Pearson χ 2 test. Multivariate Cox analysis was used to evaluate whether HIF-1α expression was associated with the prognosis of patients after controlling for confounders.

RESULTS

HIF-1α was mainly expressed in the cytoplasm or nucleus in all of the chordoma samples, which showed significantly higher than that in the normal nucleus pulposus tissue ( P =0.004). Multivariate Cox regression analyses showed that high HIF-1α expression and location of HIF-1α expression were significantly associated with poor CDFS (hazard ratio (HR)=3.374; P =0.021) and OS (HR=4.511; P =0.012). In addition, we further found that high HIF-1α expression both in the cytoplasm and nucleus indicated a stronger prognostic factor for poor CDFS (HR=3.885; P =0.011) and OS (HR=4.014; P =0.011) in spinal chordoma patients.

CONCLUSION

High HIF-1α expression may become a potential new biological indicator to predict a poor prognosis in patients with spinal chordoma. HIF-1α may also represent a novel therapeutic target for the treatment of spinal chordoma.

Development of a Small Molecule Downmodulator for the Transcription Factor Brachyury

Brachyury is an oncogenic transcription factor whose overexpression drives chordoma growth. The downmodulation of brachyury in chordoma cells has demonstrated therapeutic potential, however, as a transcription factor it is classically deemed "undruggable". Given that direct pharmacological intervention against brachyury has proven difficult, attempts at intervention have instead targeted upstream kinases. Recently, afatinib, an FDA-approved kinase inhibitor, has been shown to modulate brachyury levels in multiple chordoma cell lines. Herein, we use afatinib as a lead to undertake a structure-based drug design approach, aided by mass-spectrometry and X-ray crystallography, to develop DHC-156, a small molecule that more selectively binds brachyury and downmodulates it as potently as afatinib. We eliminated kinase-inhibition from this novel scaffold while demonstrating that DHC-156 induces the post-translational downmodulation of brachyury that results in an irreversible impairment of chordoma tumor cell growth. In doing so, we demonstrate the feasibility of direct brachyury modulation, which may further be developed into more potent tool compounds and therapies.

Unraveling molecular signatures in rare bone tumors and navigating the cancer pathway landscapes for targeted therapeutics

Rare cancers (RCs), which account for over 20% of cancer cases, face significant research and treatment challenges due to their limited prevalence. This results in suboptimal outcomes compared to more common malignancies. Rare bone tumors (RBTs) constitute 5-10% of rare cancer cases and pose unique diagnostic complexities. The therapeutic potential of anti-cancer drugs for RBTs remains largely unexplored. Identifying molecular alterations in cancer-related genes and their associated pathways is essential for precision medicine in RBTs. Small molecule inhibitors and monoclonal antibodies targeting specific RBT-associated proteins show promise. Ongoing clinical trials aim to define RBT biomarkers, subtypes, and optimal treatment contexts, including combination therapies and immunotherapeutic agents. This review addresses the challenges in diagnosing, treating, and studying RBTs, shedding light on the current state of RBT biomarkers, potential therapeutic targets, and promising inhibitors. Rare cancers demand attention and innovative solutions to improve clinical outcomes.

N6-methyladenosine-modified circTEAD1 stabilizes Yap1 mRNA to promote chordoma tumorigenesis

BACKGROUND

Chordoma, a rare bone tumour with aggressive local invasion and high recurrence rate with limited understanding of its molecular mechanisms. Circular RNAs (circRNAs) have been extensively implicated in tumorigenesis, yet their involvement in chordoma remains largely unexplored. N6-methyladenosine (m6A) modification holds a crucial function in regulating protein translation, RNA degradation and transcription.

METHODS

Initially, screening and validation of circTEAD1 in chordoma were conducted by high-throughput sequencing. Subsequently, sh-circTEAD1 and an overexpression plasmid were constructed. Colony formation assays, cell counting kit-8, Transwell and wound healing assays were utilized to validate the function of circTEAD1 in vitro. RNA pull-down assays identified the binding proteins of circTEAD1, which underwent verification through RNA immunoprecipitation (RIP). Methylated RIP assays were conducted to detect the m6A binding sites. Following this, luciferase assay, RT-qPCR, RIP and Western blotting analyses were conducted, revealing that Yap1 was the direct target of circTEAD1. Afterwards, the same methods were utilized for the validation of the function of Yap1 in chordoma in vitro. Finally, the regulatory relationship between circTEAD1 and Yap1 in chordoma was verified by an in vivo tumour formation assay.

RESULTS

CircTEAD1 was identified as an upregulated circRNA in chordoma specimens, with heightened circTEAD1 expression emerging as a prognostic indicator. In vitro experiments convincingly demonstrated that circTEAD1 significantly promoted chordoma cell invasion, migration and aggressiveness. Furthermore, the analysis revealed that methyltransferase-like 3-mediated m6A modification facilitated the cytoplasmic export of circTEAD1. The circTEAD1/IGF2BP3/Yap1 mRNA RNA-protein ternary complex not only bolstered the stability of Yap1 mRNA but also exerted a pivotal role in driving chordoma tumorigenesis.

CONCLUSIONS

In this study, the role of m6A-modified circTEAD1 in chordoma was identified. The findings offer novel insights into the potential molecular targets for chordoma therapy, shedding light on the intricate interplay between circRNAs, m6A modification and Yap1 mRNA in chordoma pathogenesis.

Dysregulation of noncoding RNA in chordoma; implications in identifying potential targets for novel therapeutic approaches

Chordoma is a rare form of bone cancer develops in the spinal cord and skull. Instead of conventional (radio/chemotherapies) and targeted therapies, the disease is associated with high rate of recurrence and poor patient survival. Thus, for better disease management, the molecular pathogenesis of chordoma should be studied in detail to identify dysregulated biomolecules that can be targeted by novel therapeutics. Recent research showed frequent dysregulation of long noncoding RNA (lncRNA), microRNA (miRNA), and circular RNA (circRNA) in association with aggressive tumor phenotypes like cell proliferation, migration, invasion, and metastasis in a variety of cancers, including chordoma. Apart from diagnostic and prognostic importance, noncoding RNAs may serve as promising targets for novel therapeutics in cancer. In this review, we summarized a list of miRNAs, lncRNAs, and circRNA found to be dysregulated in chordoma from available data published in relevant databases (PubMed), as such an approach seems to be rare to date. The dysregulated noncoding RNAs were also associated with adverse tumor phenotypes to assess the impact on disease pathogenesis and, associated downstream molecular pathways were focused. Synthetic compounds and natural products that were reported to target the noncoding RNAs in other malignancies were also listed from published literature and proposed as potential therapeutic agents in chordoma. This review will provide information for further research on chordoma focusing on detailed characterization of dysregulated lncRNAs, miRNAs, and circRNA to understand the disease pathogenesis and, exploration of suitable natural and synthetic products targeting dysregulated non-coding RNAs to develop effective therapeutic measures.

Linc01116 Silencing Inhibits the Proliferation and Invasion, Promotes Apoptosis of Chordoma Cells via Regulating the Expression of Mir-9-5p/PKG1

BACKGROUND

Long intergenic non-protein coding RNA 1116 (LINC01116) plays a carcinogenic role in a variety of cancers. The study aims to investigate the roles of LINC01116 and hsa-miR-9-5p (miR-9-5p) and fathom their interaction in chordoma.

METHODS

The predicted binding sites between miR-9-5p with LINC01116 and phosphoglycerate kinase 1 (PGK1) by starBase were confirmed through dual-luciferase reporter assay. The behaviors of chordoma cells undergoing transfection with siLINC01116 or miR-9-5p inhibitor were determined by Cell Counting Kit-8 (CCK-8), colony formation, Transwell, and flow cytometry assays. The glucose consumption, lactate production, and adenosine triphosphate (ATP) production of chordoma cells were examined with specific kits. Quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot were performed to determine relevant gene expressions in chordoma cells.

RESULTS

Silencing of LINC01116 facilitated the apoptosis and expressions of Bcl-2- associated X (Bax), cleaved caspase-3 (C caspase-3) and miR-9-5p while repressing the cell cycle, viability, proliferation, invasion, glucose consumption, lactate production, ATP production, and expressions of PGK1 and Bcl-2. Meanwhile, LINC01116 sponged miR-9-5p, which could target PGK1. Moreover, the miR-9-5p inhibitor acted contrarily and reversed the role of siLINC01116 in chordoma cells. Besides, LINC01116 downregulation facilitated apoptosis and attenuated the proliferation and invasion of chordoma cells as well as PGK1 expression by upregulating miR-9-5p expression.

CONCLUSION

LINC01116/miR-9-5p plays a regulatory role in the progression of chordoma cells and is a potential biomarker for chordoma.

Chordoma: A Comprehensive Systematic Review of Clinical Trials

This systematic review aims to characterize ongoing clinical trials and therapeutic treatment options for chordoma, a rare notochordal remnant tumor that primarily affects the cranial base, mobile spine, and sacrum. While radical surgical resection remains the cornerstone for chordoma management, unique technical challenges posed by its proximity to critical neurovascular structures confer a tendency towards disease recurrence which often requires additional treatment modalities. In an attempt to better understand the current treatment landscape, a systematic review was designed to identify clinical trials directed at chordoma. A total of 108 chordoma trials were identified from four clinical trial databases; fifty-one trials were included in the final analysis, of which only 14 were designated as completed (27.5%). Aggregate data suggests most chordoma interventions are repurposed from other neoplasms that share common molecular pathways, with a recent emphasis on combination therapeutics within and across drug classes. Naturally, the publication and dissemination of clinical trial results remain a concern (n = 4, 28.6%), highlighting the need for enhanced reporting and transparency measures. Active clinical trial efforts are quite promising, with a renewed focus on novel biotherapeutic targets and deciphering the natural history, as well as survivorship of this complex disease.

A rare case of chordoma cutis

Chordoma is a rare locally aggressive bone malignancy that originates from the notochord. It typically involves the sacrococcygeal area, spheno-occipital region of the skull, and spine. Cutaneous involvement of chordoma, termed as chordoma cutis, is uncommon and usually occurs via direct invasion or local recurrence. Distant metastasis to the skin is very rare. We report a case of chordoma cutis on the scalp, which lacked characteristic physaliferous cells but tested positive for brachyury, thus supporting the diagnosis of chordoma cutis. The patient, who presented with a solitary translucent nodule on the scalp, was previously diagnosed with chordoma on the vertebral column and skull 8 months prior. Microscopic examination showed a cord-like arrangement of plasmacytoid cells within a myxoid stroma. Physaliferous cells were not observed, and cytokeratin AE1/AE3 staining was negative; however, brachyury and epithelial membrane antigen staining was positive, leading to the diagnosis of chordoma cutis. Therefore, clinicians must include chordoma cutis in the differential diagnosis of translucent nodular lesions on the skin of patients formerly diagnosed with chordoma.

Shedding light on emerging therapeutic targets for chordoma

INTRODUCTION

Despite encouraging advances in radiation and surgical treatment, chordomas remain resistant to chemotherapy and local recurrence is common. Although the primary mechanism of recurrence is local, metastatic disease occurs in a small subset of patients. Recurrence may also occur along the surgical trajectory if care is not taken to fully excise the open biopsy pathway. There is increasing morbidity with reoperation upon disease recurrence, and radiation is an option for cytoreduction in primary disease or for recurrent disease, although toxicity may be observed with high-dose therapies. Given these challenges, targeted chemotherapeutic agents for postoperative adjuvant treatment are needed.

AREAS COVERED

In this review, we summarize the genetic drivers of chordoma and the state of the current research in chordoma immunotherapy and epigenetics.

EXPERT OPINION

Chordoma is a heterogenous tumor that should be targeted from different angles and the study of its characteristics, from molecular to immunological to epigenetic, is necessary. Combining different approaches, such as studying noninvasive patient methylation patterns with tissue-based molecular and drug screening, can transform patient care by guiding treatment decisions based on prognostic mechanisms from different sources, while helping individualize surgical planning and treatment.

The NIH pediatric/young adult chordoma clinic and natural history study: Making advances in a very rare tumor

BACKGROUND

Chordomas are rare tumors arising from the skull base and spine, with approximately 20 pediatric chordoma cases in the Unitedn States per year. The natural history and optimal treatment of pediatric chordomas, especially poorly differentiated and dedifferentiated subtypes, is incompletely understood. Herein, we present findings from our first National Cancer Institute (NCI) chordoma clinic and a retrospective analysis of published cases of pediatric poorly differentiated chordomas (PDC) and dedifferentiated chordomas (DC).

METHODS

Patients less than 40 years old with chordoma were enrolled on the NCI Natural History and Biospecimens Acquisitions Study for Children and Adults with Rare Solid Tumors protocol (NCT03739827). Chordoma experts reviewed patient records, evaluated patients, and provided treatment recommendations. Patient-reported outcomes, biospecimens, and volumetric tumor analyses were collected. A literature review for pediatric PDC and DC was conducted.

RESULTS

Twelve patients (median age: 14 years) attended the clinic, including four patients with active disease and three patients with PDC responsive to systemic therapy. Consensus treatment, management, and recommendations were provided to patients. Literature review returned 45 pediatric cases of PDC or DC with variable treatments and outcomes.

CONCLUSIONS

A multidisciplinary expert clinic was feasible and successful in improving understanding of pediatric chordoma. While multimodal approaches have all been employed, treatment for PDC has been inconsistent and a recommended standardized treatment approach has not been defined. Centralized efforts, inclusive of specialized chordoma-focused clinics, natural history studies, and prospective analyses will help in the standardization of care for this challenging disease.

A 13-year patient journey of infant giant clival chordoma: case report and literature review

Chordomas are rare malignant bone tumours that develop from the ectopic remnants of the embryonic notochord. In contrast to adults, the majority in children under 16 present intra-cranially (63%). In 2006, we reported the youngest case of a large clival chordoma, a 15-week old baby, the second case to present without skull base involvement and the fourth case of chordoma in a patient with tuberous sclerosis (TS) Kombogiorgas (Childs Nerv Syst 22(10):1369-1374, 2006). In this report, we provide an update on this patient's journey through a range of therapeutic options and summarize an update of the literature, since 2006, for this patient group.

Transcriptional Profiling Supports the Notochordal Origin of Chordoma and Its Dependence on a TGFΒ1-TBXT Network

Chordoma is a rare malignant tumor demonstrating notochordal differentiation. It is dependent on brachyury (TBXT), a hallmark notochordal gene and transcription factor, and shares histologic features and the same anatomic location as the notochord. In this study, we perform a molecular comparison of chordoma and notochord to identify dysregulated cellular pathways. The lack of a molecular reference from appropriate control tissue limits our understanding of chordoma and its relationship to notochord. Accordingly, we conducted an unbiased comparison of chordoma, human notochord, and an atlas of normal and cancerous tissue using gene expression profiling to clarify the chordoma/notochord relationship and potentially identify novel drug targets. We found striking consistency in gene expression profiles between chordoma and notochord, supporting the hypothesis that chordoma develops from notochordal remnants. We identified a 12-gene diagnostic chordoma signature and found that the TBXT/transforming growth factor (TGF)-β/SOX6/SOX9 pathway is hyperactivated in the tumor, suggesting that pathways associated with chondrogenesis are a central driver of chordoma development. Experimental validation in chordoma cells confirms these findings and emphasizes the dependence of chordoma proliferation and survival on TGF-β. Our computational and experimental evidence provides the first molecular connection between notochord and chordoma and identifies core members of a chordoma regulatory pathway involving TBXT. This pathway provides new therapeutic targets for this unique malignant neoplasm and highlights TGF-β as a prime druggable candidate.

Low expression of H3K27me3 is associated with poor prognosis in conventional chordoma

Purpose

Chordoma is a rare and locally invasive neoplasm, and the prognostic factors are limited. Deregulation of Histone 3 lysine 27 (H3K27) trimethylation (H3K27me3) is considered to be related with poor prognosis in some tumors. The purpose of this study was to detect the expression of H3K27me3 in chordomas and analyze the correlation with clinicopathological features and explore the roles as potential prognostic markers and therapeutic targets.

Material and method

Specimens of 162 chordoma patients (consisting of 156 conventional chordoma, 4 dedifferentiated chordoma and 2 poorly differentiated chordoma) were enrolled in a tissue microarray (TMA) in order to assess the immunohistochemical staining by H3K27me3 antibodies. Correlations between H3K27me3 expression and clinicopathological features were analyzed. Clinical data of the patients were correlated and survival analysis was performed. Kaplan-Meier survival curves and log-rank test were used to analyze the recurrence-free survival (RFS) and overall survival (OS). Multivariate Cox regression analyses were used to identify potential prognostic factors.

Results

The expression of H3K27me3 was lower in 37 chordoma patients (37/162, 22.8%), and higher in 125 patients (125/162, 77.2%). H3K27me3-low expression significantly correlated with spine location (P < 0.001), conventional histological subtype (P < 0.001), and recurrence (P < 0.001). Log-rank test showed that H3K27me3-low expression was associated with poor RFS (P =0.027) and OS (P =0.009) in conventional chordoma patients. Cox multivariate analysis revealed that low expression of H3K27me3 was an independent predictor of poor OS (P =0.007) and RFS (P =0.025) in conventional chordoma patients.

Conclusions

Our study indicates that low expression of H3K27me3 might be considered as a predictor for poor prognosis and recurrence, and it may provide a potential therapeutic target for conventional chordoma patients.

Bibliometric analysis of the global research trends and hotspots in chordoma from 2000 to 2020

INTRODUCTION

Chordoma is formed from embryonic residues or ectopic chordae and locally aggressive or malignant tumors. We visually analyzed the research tendency and hotspot of chordoma.

METHODS

The bibliometric analysis was conducted from the Web of Science Core Collection database over the past two decades. The term and strategies were as follows: "TS = (chordoma) OR TS = (chordoblastoma) OR TS = (chordocarcinoma) OR TS = (chordoepithelioma) OR TS = (chordosarcoma) OR TS = (notochordoma). AND Language: English. AND Reference Type: Article OR Review". A total of 2,118 references were retrieved and used to make a visual analysis by VOSviewer 1.6.15.

RESULTS

The chordoma was on a steady rise and chordoma but remained the focus of scholars and organizations over the last two decades. The Chinese institutions and scholars lacked cooperation with their counterparts in other countries. The citations of documents and co-citation analysis of cited references suggested that M.L. McMaster, B.P. Walcott, P. Bergh, and S. Stacchiotti were leading researchers in this field of chordoma and their papers had been widely accepted and inspired recent researches. Keywords associated with recent chemotherapy, PD-1-related immunotherapy, and SMARCB1/integrase interactor 1 (INI1) in chordoma were a shortage of research and there may be more research ideas in the future by scholars. The research of chordoma will continue to be the hotspot.

CONCLUSIONS

Thus, explaining the molecular mechanism and potential role of transcriptional inhibition and immunologic responses to SMARCB1/INI1-negative poorly differentiated chordoma will be available for preclinical experiments and clinical trials and lead to new therapeutic opportunities for chordoma patients.

Immune Checkpoint Inhibitors Have Clinical Activity in Patients With Recurrent Chordoma

The aim of this study is to evaluate the outcomes and tolerance of immune checkpoint inhibitors (ICIs) for patients with recurrent chordoma. We reviewed the records of 17 patients with recurrent chordomas who received ICIs for progressing disease as part of their treatment between 2016 and 2020. Response was assessed using response evaluation criteria in solid tumors 1.1 criteria. The Kaplan-Meier method was used to estimate the duration of response, progression-free survival (PFS), and overall survival (OS). Clinical benefit was defined as having stable disease (SD), a partial response, or a complete response. The median follow-up from the start of ICIs was 29 months [interquartile range (IQR): 13-35 m]. The majority received pembrolizumab (n=9, 53%), and the median number of cycles delivered was 8 (IQR: 7-12). The 1-year OS was 87%, and the 1-year PFS was 56% with a median PFS of 14 months (95% CI, 5-17 mo). After ICI initiation, most patients (n=15, 88%) had clinical benefit consisting of a complete response (n=1, 6%), partial response (n=3, 18%), and stable disease (n=11, 65%). Among all responders (n=15), the median duration of response was 12 months. Toxicities were limited: 2 (12%) patients having grade 3/4 immune-related toxicities (colitis, grade 3; myocarditis, grade 4). We observed a high rate of clinical benefit and favorable durability from ICI use for patients with recurrent chordoma. These data provide support for the integration of ICIs as a standard first-line systemic therapy option for patients with recurrent chordoma. Prospective studies are warranted to further evaluate efficacy and enhance response rates.

Research hotspots and trends of chordoma: A bibliometric analysis

Background

Chordoma is a type of mesenchymal malignancy with a high recurrence rate and poor prognosis. Due to its rarity, the tumorigenic mechanism and optimal therapeutic strategy are not well known.

Methods

All relevant articles of chordoma research from 1 January 2000 to 26 April 2022 were obtained from Web of Science Core Collection database. Blibliometrix was used to acquire basic publication data. Visualization and data table of collaboration network, dynamic analysis, trend topics, thematic map, and factorial analysis were acquired using Blibliometrix package. VOSviewer was used to generate a visualization map of co-citation analysis and co-occurrence.

Results

A total of 2,285 articles related to chordoma were identified. The most influential and productive country/region was the United States, and Capital Medical University has published the most articles. Among all high-impact authors, Adrienne M. Flanagan had the highest average citation rate. Neurosurgery was the important periodical for chordoma research with the highest total/average citation rate. We focused on four hotspots in recent chordoma research. The research on surgical treatment and radiotherapy was relatively mature. The molecular signaling pathway, targeted therapy and immunotherapy for chordoma are not yet mature, which will be the future trends of chordoma research.

Conclusion

This study indicates that chordoma studies are increasing. Surgery and radiotherapy are well reported and always play fundamental roles in chordoma treatment. The molecular signaling pathway, targeted therapy, and immunotherapy of chordoma are the latest research hotspots.

Metastatic skull base chordoma: A systematic review

Objective/Hypothesis

To investigate the clinical features, management strategies and outcomes for patients with metastatic primary skull base chordomas.

Study Design

Systematic review.

Methods

A systematic search through Pubmed/Medline, Web of Science, and EBSCOhost (CINAHL) was conducted without restriction on dates. After study screening and full‐text assessment, two authors independently extracted all data using a pre‐established abstraction form.

Results

Forty cases were included from 38 studies. The average age (standard deviation [SD]) of the sample at presentation was 28.5 (23.3) and was equally distributed across genders. The average time (SD) between initial diagnosis to local recurrence was 40.1 (60.3) months. The average time (SD) from primary tumor detection to the diagnosis of metastatic disease was 55.2 (49.0) months. The most common subsite for metastatic spread were the lungs (32.5%). Of the 33 patients with data on outcomes, 48.5% were found to have expired by the time of publication. The median overall survival was estimated to be 84 months (95% confidence interval [CI] 62.3–105.7).

Conclusions

The most common subsites for metastatic spread of skull base chordoma were the lungs and bone. Overall survival for patients in the current cohort was a median of 84 months, with no significant differences noted when stratifying by the extent of surgery or the site of metastases.

Level of Evidence

3a

Selinexor inhibits growth of patient derived chordomas in vivo as a single agent and in combination with abemaciclib through diverse mechanisms

Chordoma is a rare cancer that grows in the base of the skull and along the mobile spine from remnants of embryonic notochord tissue. The cornerstone of current treatments is surgical excision with adjuvant radiation therapy, although complete surgical removal is not always possible. Chordomas have high rates of metastasis and recurrence, with no approved targeted agents. Selinexor and eltanexor are selective inhibitors of nuclear export (SINE) that prevent the karyopherin protein exportin-1 (XPO1) from shuttling its cargo proteins through nuclear pore complexes out of the nucleus and into the cytoplasm. As cancer cells overexpress XPO1, and many of its cargos include tumor suppressor proteins and complexes bound to oncogene mRNAs, XPO1 inhibition can suppress oncogene translation and restore tumor suppressor protein activity in different cancer types. SINE compounds have exhibited anti-cancer activity in a wide range of hematological and solid tumor malignancies. Here we demonstrate the preclinical effectiveness of SINE compounds used as single agents or in combination with either the proteasome inhibitor, bortezomib, or the CDK4/6 inhibitor, abemaciclib, against various patient- derived xenograft (PDX) mouse models of chordoma, which included clival and sacral chordomas from adult or pediatric patients with either primary or metastatic disease, with either differentiated or poorly differentiated subtypes. SINE treatment significantly impaired tumor growth in all five tested chordoma models, with the selinexor and abemaciclib combination showing the strongest activity (tumor growth inhibition of 78-92%). Immunohistochemistry analysis of excised tumors revealed that selinexor treatment resulted in marked induction of apoptosis and reduced cell proliferation, as well as nuclear accumulation of SMAD4, and reduction of Brachyury and YAP1. RNA sequencing showed selinexor treatment resulted in differences in activated and repressed signaling pathways between the PDX models, including changes in WNT signaling, E2F pathways and glucocorticoid receptor signaling. This is consistent with SINE-compound mediated XPO1 inhibition exhibiting anti-cancer activity through a broad range of different mechanisms in different molecular chordoma subsets. Our findings validate the need for further investigation into selinexor as a targeted therapeutic for chordoma, especially in combination with abemaciclib.

Chordoma at the skull base, spine, and sacrum: A pictorial essay

Chordomas are rare tumors believed to be arising from the notochord remnant in the axial skeleton. Diagnosis is often difficult since they show overlapping imaging features with other more common disease including metastases. Since individualized papers are only discussing the imaging features at different locations, the aim of this pictorial review is to have a comprehensive review on the common imaging findings of chordomas along the entire neuroaxis with a series of pathological proven cases in a local tertiary hospital in Hong Kong.

Pediatric chordoma associated with tuberous sclerosis complex: A rare case report with a thorough analysis of potential therapeutic molecular targets

Chordoma associated with tuberous sclerosis complex (TSC) is an extremely rare tumor that was described only in 13 cases since 1975. Сhordoma itself is a malignant slow-growing bone tumor thought to arise from vestigial or ectopic notochordal tissue. Chordoma associated with TSC differs from chordoma in the general pediatric population in the median age, where the diagnosis of TSC-associated chordoma is 6.2 months, whereas for chordoma in the general pediatric population it is set to 12 years. The majority of TSC-associated chordomas are localized in skull-based and sacrum regions, and rare in the spine. Chordomas are genetically heterogeneous tumors characterized by chromosomal instability (CIN), and alterations involving PI3K-AKT signaling pathway genes and chromatin remodeling genes. Here we present the 14th case of chordoma associated with TSC in a 1-year-old pediatric patient. Alongside biallelic inactivation of the TSC1 gene, molecular genetic analysis revealed CIN and involvement of epigenetic regulation genes. In addition, we found the engagement of CBX7 and apolipoprotein B editing complex (APOBEC3) genes that were not yet seen in chordomas before. Amplification of CBX7 may epigenetically silence the CDKN2A gene, whereas amplification of APOBEC3 genes can explain the frequent occurrence of CIN in chordomas. We also found that KRAS gene is located in the region with gain status, which may suggest the ineffectiveness of potential EGFR monotherapy. Thus, molecular genetic analysis carried out in this study broadens the horizons of possible approaches for targeted therapies with potential applications for personalized medicine.

Potential molecular mechanism in self-renewal is associated with miRNA dysregulation in sacral chordoma - A next-generation RNA sequencing study

Background

Chordoma, the most frequent malignant primary spinal neoplasm, characterized by a high rate of recurrence, is an orphan disease where the clarification of the molecular oncogenesis would be crucial to developing new, effective therapies. Dysregulated expression of non-coding RNAs, especially microRNAs (miRNA) has a significant role in cancer development.

Methods

Next-generation RNA sequencing (NGS) was used for the combinatorial analysis of mRNA-miRNA gene expression profiles in sacral chordoma and nucleus pulposus samples. Advanced bioinformatics workflow was applied to the data to predict miRNA-mRNA regulatory networks with altered activity in chordoma.

Results

A large set of significantly dysregulated miRNAs in chordoma and their differentially expressed target genes have been identified. Several molecular pathways related to tumorigenesis and the modulation of the immune system are predicted to be dysregulated due to aberrant miRNA expression in chordoma. We identified a gene set including key regulators of the Hippo pathway, which is targeted by differently expressed miRNAs, and validated their altered expression by RT-qPCR. These newly identified miRNA/RNA interactions are predicted to have a role in the self-renewal process of chordoma stem cells, which might sustain the high rate of recurrence for this tumor.

Conclusions

Our results can significantly contribute to the designation of possible targets for the development of anti-chordoma therapies.

Involvement of Phytochemical-Encapsulated Nanoparticles' Interaction with Cellular Signalling in the Amelioration of Benign and Malignant Brain Tumours

Brain tumours have unresolved challenges that include delay prognosis and lower patient survival rate. The increased understanding of the molecular pathways underlying cancer progression has aided in developing various anticancer medications. Brain cancer is the most malignant and invasive type of cancer, with several subtypes. According to the WHO, they are classified as ependymal tumours, chordomas, gangliocytomas, medulloblastomas, oligodendroglial tumours, diffuse astrocytomas, and other astrocytic tumours on the basis of their heterogeneity and molecular mechanisms. The present study is based on the most recent research trends, emphasising glioblastoma cells classified as astrocytoma. Brain cancer treatment is hindered by the failure of drugs to cross the blood–brain barrier (BBB), which is highly impregnableto foreign molecule entry. Moreover, currently available medications frequently fail to cross the BBB, whereas chemotherapy and radiotherapy are too expensive to be afforded by an average incomeperson and have many associated side effects. When compared to our current understanding of molecularly targeted chemotherapeutic agents, it appears that investigating the efficacy of specific phytochemicals in cancer treatment may be beneficial. Plants and their derivatives are game changers because they are efficacious, affordable, environmentally friendly, faster, and less toxic for the treatment of benign and malignant tumours. Over the past few years, nanotechnology has made a steady progress in diagnosing and treating cancers, particularly brain tumours. This article discusses the effects of phytochemicals encapsulated in nanoparticles on molecular targets in brain tumours, along with their limitations and potential challenges.

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.

Personalized chordoma organoids for drug discovery studies

Chordomas are rare tumors of notochordal origin, most commonly arising in the sacrum or skull base. Chordomas are considered insensitive to conventional chemotherapy, and their rarity complicates running timely and adequately powered trials to identify effective treatments. Therefore, there is a need for discovery of novel therapeutic approaches. Patient-derived organoids can accelerate drug discovery and development studies and predict patient responses to therapy. In this proof-of-concept study, we successfully established organoids from seven chordoma tumor samples obtained from five patients presenting with tumors in different sites and stages of disease. The organoids recapitulated features of the original parent tumors and inter- as well as intrapatient heterogeneity. High-throughput screenings performed on the organoids highlighted targeted agents such as PI3K/mTOR, EGFR, and JAK2/STAT3 inhibitors among the most effective molecules. Pathway analysis underscored how the NF-κB and IGF-1R pathways are sensitive to perturbations and potential targets to pursue for combination therapy of chordoma.

Targeted delivery of cancer drug paclitaxel to chordomas tumor cells via an RNA nanoparticle harboring an EGFR aptamer

Paclitaxel has been extensively used in clinics for cancer treatment. However, its limited solubility in aqueous solution and high occurrence of side effects have also been widely reported. In this study, we constructed a biocompatible RNA nanoparticle delivery system (3WJ-EGFR_apt) that includes 3WJ (3-way junction) nanoparticle with a size of 4.85 ± 0.59 nm as a backbone and an EGFR (epidermal growth factor receptor) aptamer for specific targeting to chordomas cells, which owns the encapsulation ability of drug paclitaxel (PTX) for cancer therapy. Confocal microscopy and flow cytometry results confirmed 3WJ-EGFR_apt nanoparticle exhibited excellent specific targeting to chordomas cell U-CH2 which is an EGFR(+) cell line; while the 3WJ nanoparticle lose the targeted ability. Both of the two nanoparticles own no sensitivity to lung cancer cell H520 which is an EGFR(-) cell line. Moreover, the 3WJ-EGFR_apt nanoparticle encapsulated drug PTX could enhance the inhibition efficiency of chordomas tumor cells U-CH2 as compared to free PTX alone. This work demonstrates that RNA-3WJ constructed with a targeting aptamer provides a compromising targeted drug delivery ability on chordomas cells for therapeutics.

Advancement of PI3 Kinase Inhibitor Combination Therapies for PI3K-Aberrant Chordoma

Objectives  Targeted inhibitors of the PI3 kinase (PI3K) pathway have shown promising but incomplete antitumor activity in preclinical chordoma models. The aim of this study is to advance methodology for a high-throughput drug screen using chordoma models to identify new combination therapies for chordoma. Study Design  Present work is an in vitro study. Setting  The study conducted at an academic research laboratory. Materials and Methods  An in vitro study on automated high-throughput screening of chordoma cells was performed using a library of 1,406 drugs as both mono- and combination therapies with PI3K inhibitors. Combination indices were determined for dual therapies and synergistic outliers were identified as potential therapeutic agents. T (brachyury) siRNA knockdown in combination with PI3K pathway inhibition was also assessed. Results  Fifty-nine combination therapies were identified as having potential therapeutic efficacy. Effective combinations included PI3K inhibitors with GSK1838705A (ALK/IGF-1R inhibitor), LY2874455 (VEGFR/FGFR inhibitor), El1 (selective Ezh2 inhibitor), and (-)-p-bromotetramisole oxalate (alkaline phosphatase inhibitor). The top ranking targets identified included ALK, PDGFR, VEGFR, aurora kinase, and BCL-2. T (brachyury) inhibition produced significant reduction in cell viability and growth; however PI3K inhibition in combination with T (brachyury) knockdown did not result in further reduction in growth and viability in vitro. Conclusion  High throughput with in vitro combination screening is feasible with chordoma cells and allows for rapid identification of synergistic dual-therapies. Potential combination therapies and targetable pathways were identified. T (brachyury) knockdown produced significant reduction in cell viability, but did not show additional benefit with PI3K pathway inhibition in this model. Further in vitro and in vivo validation of these therapeutic combinations is warranted.

The potential role of miR-1290 in cancer progression, diagnosis, prognosis, and treatment: An oncomiR or onco-suppressor microRNA?

Cancer is one of the leading causes of death in humans because of the lack of early diagnosis, distant metastases, and the resistance to adjuvant therapies, including chemotherapy and radiotherapy. In addition to playing an essential role in tumor progression and development, microRNAs (miRNAs) can be used as a robust biomarker in the early detection of cancer. MiR-1290 was discovered for the first time in human embryonic stem cells, and under typical physiological situations, plays an essential role in neuronal differentiation and neural stem cell proliferation. Its coding sequence is located at the 1p36.13 regions in the first intron of the aldehyde dehydrogenase 4 gene member A1. miR-1290 is out of control in many cancers such as breast cancer, colorectal cancer, esophageal squamous cell carcinoma, gastric cancer, lung cancer, pancreatic cancer, and plays a vital role in their development. Therefore, it is suggested that miR-1290 can be considered as a potential diagnostic and therapeutic target in many cancers. In addition to the importance of miR-1290 in the noninvasive diagnosis of various cancers, this systematic review study discussed the role of miR-1290 in altering the expression of different genes involved in cancer development and chemo-radiation resistance. Moreover, it considered the regulatory effect of natural products on miR-1290 expression and the interaction of lncRNAs by miR-1290.

Multivariate Analysis and Validation of the Prognostic Factors for Skull Base Chordoma

Background: Skull base chordoma is a rare tumor with low-grade malignancy and a high recurrence rate, the factors affecting the prognosis of patients need to be further studied. For that, we investigated prognostic factors of skull base chordoma through the database of the Surveillance, Epidemiology, and End Results (SEER) program, and validated in an independent data set from the Xiangya Hospital.

Methods: Six hundred and forty-three patients diagnosed with skull base chordoma were obtained from the SEER database (606 patients) and the Xiangya Hospital (37 patients). Categorical variables were selected by Chi-square test with a statistical difference. Survival curves were constructed by Kaplan–Meier analysis and compared by log-rank test. Univariate and multivariate Cox regression analyses were used to explore the prognostic factors. Propensity score matching (PSM) analysis was undertaken to reduce the substantial bias between gross total resection (GTR) and subtotal resection (STR) groups. Furthermore, clinical data of 37 patients from the Xiangya Hospital were used as validation cohorts to check the survival impacts of the extent of resection and adjuvant radiotherapy on prognosis.

Results: We found that age at diagnosis, primary site, disease stage, surgical treatment, and tumor size was significantly associated with the prognosis of skull base chordoma. PSM analysis revealed that there was no significant difference in the OS between GTR and STR (p = 0.157). Independent data set from the Xiangya Hospital proved no statistical difference in OS between GTR and STR groups (p = 0.16), but the GTR group was superior to the STR group for progression-free survival (PFS) (p = 0.048). Postoperative radiotherapy does not improve OS (p = 0.28), but it can prolong PFS (p = 0.0037). Nomograms predicting 5- and 10-year OS and DSS were constructed based on statistically significant factors identified by multivariate Cox analysis. Age, primary site, tumor size, surgical treatment, and disease stage were included as prognostic predictors in the nomograms with good performance.

Conclusions: We identified age, tumor size, surgery, primary site, and tumor stage as main factors affecting the prognosis of the skull base chordoma. Resection of the tumor as much as possible while ensuring safety, combined with postoperative radiotherapy may be the optimum treatment for skull base chordoma.

B7-H3 as a Target for CAR-T Cell Therapy in Skull Base Chordoma

Objective

chordomas are rare bone tumors with few therapeutic options. Skull base and sacrum are the two most common origin sites. Immunotherapies are emerging as the most promising approaches to fight various cancers. This study tends to identify new cell surface targets for immunotherapeutic options of skull base chordomas.

Methods

we profiled 45 skull base chordoma clinical samples by immunohistochemistry for the expression of six CAR-Targets (PD-L1, B7-H3, B7-H4, VISTA, HER2 and HER3). In addition, we generated B7-H3 targeted CAR-T-cells and evaluated their antitumor activities in vitro.

Results

We found that B7-H3 was positively stained in 7 out of 45 (16%) chordoma samples and established an expression hierarchy for these antigens (B7-H3 > HER3 > PD-L1 > HER2 = VISTA = B7-H4). We then generated a B7-H3 targeted CAR vector and demonstrated that B7-H3-CAR-T-cells recognized antigen positive cells and exhibited significant antitumor effects, including suppression of tumor spheroid formation, CAR-T-cell activation and cytokine secretion.

Conclusions

Our results support B7-H3 might serve as a promising target for CAR-T-cell therapies against chordomas.

Loss of SMARCB1 promotes autophagy and facilitates tumour progression in chordoma by transcriptionally activating ATG5

OBJECTIVES

SWI/SNF-related matrix-associated actin-dependent regulator of chromatin subfamily B member 1 (SMARCB1) loss is associated with a poor prognosis in chordoma, while the mechanism remains largely unclear. Here, we aim to explore the function and regulatory mechanisms of SMARCB1 in chordoma.

MATERIALS AND METHODS

The effect of SMARCB1 on chordoma cells was investigated in vitro and in vivo. Chromatin immunoprecipitation (ChIP) sequencing was used to investigate the mechanisms of SMARCB1 in chordoma. The association between SMARCB1 and autophagy was validated by Western blot, immunofluorescence and transmission electron microscopy. In addition, the ATG5 expression in chordoma tissue was assessed using immunohistochemistry and correlated with patient survival.

RESULTS

SMARCB1 inhibited the malignant phenotype of chordoma cells in vitro and in vivo, supporting a tumour suppressor role of SMARCB1 in chordoma. ATG5-mediated autophagy was identified as a potential downstream pathway of SMARCB1. Mechanistically, SMARCB1 bound directly to the ATG5 promoter and epigenetically inhibited its transcription, which decreased ATG5 expression and impaired autophagy. Additionally, autophagy inhibitor chloroquine had a potential anti-cancer effect on chordoma cells in vitro. Moreover, high ATG5 expression was observed in recurrent chordoma patients, which independently correlated with adverse outcomes.

CONCLUSIONS

Taken together, our results revealed that the SMARCB1/ATG5 axis is a promising therapeutic target for chordoma and autophagy inhibitors may be effective agents for chordoma treatment.

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.

Any Etiquette for Sacrococcygeal Chordoma's Diagnosis?

The current paper focuses on a trial to understand the imaging manifestations in combination with the clinical presentation of the sacrococcygeal chordoma in a patient with referred back pain. Also, the steps for the final diagnosis are described and via this procedure, the paper demonstrates the crucial role of magnetic resonance imaging, computed tomography guided biopsy and histopathological examination in order to minimize the differential diagnosis and lead to the correct diagnosis.

DNA Methylation based prognostic subtypes of chordoma tumors in tissue and plasma

BACKGROUND

Chordomas are rare malignant bone cancers of the skull-base and spine. Patient survival is variable and not reliably predicted using clinical factors or molecular features. This study identifies prognostic epigenetic chordoma subtypes that are detected non-invasively using plasma methylomes.

METHODS

Methylation profiles of 68 chordoma surgical samples were obtained between 1996-2018 across three international centres along with matched plasma methylomes where available.

RESULTS

Consensus clustering identified two stable tissue clusters with a disease-specific survival difference that was independent of clinical factors in a multivariate Cox analysis (HR=14.2, 95%CI: 2.1-94.8, p=0.0063). Immune-related pathways with genes hypomethylated at promoters and increased immune cell abundance were observed in the poor-performing "Immune-infiltrated" subtype. Cell-to-cell interaction plus extracellular matrix pathway hypomethylation and higher tumor purity was observed in the better-performing "Cellular" subtype. The findings were validated in additional DNA methylation and RNA sequencing datasets as well as with immunohistochemical staining. Plasma methylomes distinguished chordomas from other clinical differential diagnoses by applying fifty chordoma-versus-other binomial generalized linear models in random 20% testing sets (mean AUROC=0.84, 95%CI: 0.52-1.00). Tissue-based and plasma-based methylation signals were highly correlated in both prognostic clusters. Additionally, leave-one-out models accurately classified all tumors into their correct cluster based on plasma methylation data.

CONCLUSIONS

Here, we show the first identification of prognostic epigenetic chordoma subtypes and first use of plasma methylome-based biomarkers to non-invasively diagnose and subtype chordomas. These results may transform patient management by allowing treatment aggressiveness to be balanced with patient risk according to prognosis.

Multidisciplinary Management of Primary Sacral Tumors: A Tertiary Care Center's Experience and Literature Review

Sacral tumors are rare and can be benign or malignant. Their management is multifactorial and is based on the pathology, extent, and local and distant spread. Managing sacral tumors is challenging due to their proximity to visceral and neural structures. Surgical wide excision has been the standard of care for aggressive benign and malignant tumors. Our purpose was to evaluate the outcomes of a multimodal approach to managing primary sacral tumors in Sakra World Hospital, a tertiary spine care center in Bengaluru, India and perform a literature review to determine a workflow pathway. Our study was a retrospective review of patient records and included 15 patients with primary sacral tumors. Eleven surgically treated patients were evaluated clinically and radiologically and underwent biopsy before surgical excision by an all-posterior approach. A multidisciplinary approach that included intraoperative neural monitoring, plastic reconstruction, adjuvant chemotherapy, and radiotherapy was implemented whenever necessary. Sacral root preservation was attempted whenever feasible. Functional outcomes (based on the Visual Analog Scale [VAS] and Biagini scoring system) were analyzed along with disease control, with a minimum of 2 years of follow-up. The mean follow-up was 29±9.8 months. The mean VAS score significantly improved from 7.8±2.6 to 3.7±3.8 (p=0.026). Bowel function showed statistically significant improvement, from a mean score of 0.81±0.47 to 0.63±0.52 (p=0.026) at 2 years of follow-up. The mean pretreatment motor and bladder function scores were 0.53±0.31 and 0.74±0.44, respectively, improving to 0.48±0.33 and 0.68±0.56 at follow-up but without statistical significance. There was no significant loss of function, which is expected in radical sacral resections. In conclusion, primary sacral tumors require a multidisciplinary approach and management for optimal outcomes. A stand-alone posterior approach can be employed to treat most sacral lesions. En-bloc wide resection is the optimal treatment for primary malignant and aggressive benign tumors. Preservation of at least one functional S2 nerve root is imperative to preserve bowel and bladder function.

Drug combination screening as a translational approach toward an improved drug therapy for chordoma

Purpose

Drug screening programmes have revealed epidermal growth factor receptor inhibitors (EGFR_is) as promising therapeutics for chordoma, an orphan malignant bone tumour, in the absence of a known genetic driver. Concurrently, the irreversible EGFR_i afatinib (Giotrif®) is being evaluated in a multicentric Phase II trial. As tyrosine kinase inhibitor (TKI) monotherapies are invariably followed by resistance, we aimed to evaluate potential therapeutic combinations with EGFR_is.

Methods

We screened 133 clinically approved anticancer drugs as single agents and in combination with two EGFR_is (afatinib and erlotinib) in the clival chordoma cell line UM-Chor1. Synergistic combinations were analysed in a 7 × 7 matrix format. The most promising combination was further explored in clival (UM-Chor1, MUG-CC1) and sacral (MUG-Chor1, U-CH1) chordoma cell lines. Secretomes were analysed for receptor tyrosine kinase ligands (EGF, TGF-α, FGF-2 and VEGF-A) upon drug treatment.

Results

Drugs that were active as single agents (n = 45) included TKIs, HDAC and proteasome inhibitors, and cytostatic drugs. Six combinations were analysed in a matrix format: n = 4 resulted in a significantly increased cell killing (crizotinib, dabrafenib, panobinostat and doxorubicin), and n = 2 exhibited no or negligible effects (regorafenib, venetoclax). Clival chordoma cell lines were more responsive to combined EGFR-MET inhibition. EGFR-MET cross-talk (e.g. via TGF-α secretion) likely accounts for the synergistic effects of EGFR-MET inhibition.

Conclusion

Our screen revealed promising combinations with EGFR_is, such as the ALK/MET-inhibitor crizotinib, the HDAC-inhibitor panobinostat or the topoisomerase-II-inhibitor doxorubicin, which are part of standard chemotherapy regimens for various bone and soft-tissue sarcomas.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13402-021-00632-x.

DEPDC1B regulates the progression of human chordoma through UBE2T-mediated ubiquitination of BIRC5

Chordoma is a rare bone malignancy with a high rate of local recurrence and distant metastasis. Although DEP domain-containing protein 1B (DEPDC1B) is implicated in a variety of malignancies, its relationship with chordoma is unclear. In this study, the biological role and molecular mechanism of DEPDC1B in chordoma were explored. The function of DEPDC1B in chordoma cells was clarified through loss-of-function assays in vitro and in vivo. Furthermore, molecular mechanism of DEPDC1B in chordoma cells was recognized by RNA sequencing and Co-Immunoprecipitation (Co-IP) assay. The malignant behaviors of DEPDC1B knockdown chordoma cells was significantly inhibited, which was characterized by reduced proliferation, enhanced apoptosis, and hindered migration. Consistently, decreased expression of DEPDC1B suppressed tumor growth in xenograft mice. Mechanically, DEPDC1B affected the ubiquitination of baculoviral inhibitor of apoptosis repeat-containing 5 (BIRC5) through ubiquitin-conjugating enzyme E2T (UBE2T). Simultaneous downregulation of BIRC5 and DEPDC1B may exacerbate the inhibitory effects of chordoma. Moreover, BIRC5 overexpression reduced the inhibitory effects of DEPDC1B knockdown in chordoma cells. In conclusion, DEPDC1B regulates the progression of human chordoma through UBE2T-mediated ubiquitination of BIRC5, suggesting that it may be a promising candidate target with potential therapeutic value.

A rare case of chordoma presenting as a Pancoast tumor

The notochord is the defining structure of all chordate embryos. It is a midline structure ventral to the ectoderm, neural plates, and neural arch. Remnants of the notochord ultimately give rise to the nucleus pulposus. The function of the notochord is to organize the surrounding structures. Chordoma is a rare malignant bone tumor arising from remnants of the notochord. These tumors are indolent and can present as incidental or locally advanced involving adjacent structures. These tumors typically present at the skull base and sacral spine but more rarely can be seen on the cervical and thoracic spine. Rare cases of chordoma invading the brachial plexus have been recorded. Surgical resection is the mainstay of treatment for chordomas. We would like to discuss a novel presentation of a chordoma as a Pancoast tumor, and aim to highlight the clinical importance of accurate diagnosis and planning therapy along with poor prognosis of incomplete surgical resection.

Chordoma: Current status, problems, and future directions

Chordoma is a rare tumor that occurs along the axial spine in pediatrics and adults, with an incidence of approximately 350 cases per year in the United States. While typically described as slow-growing, many patients will eventually develop loco-regional relapse or metastatic disease with few treatment options. Despite numerous efforts over the last 10+ years, effective treatments for patients are lacking. As subtypes of chordoma are identified and described in more detail, further knowledge regarding the natural history of each type, tumor location, age differences, genomic variability, and an overall better understanding of chordoma may be the key to developing meaningful clinical trials and effective therapies for patients with chordoma.

Biological Treatments of Neurofibromatosis Type 2 and Other Skull Base Disorders

Studies of genomic alterations that occur in skull base tumors have provided information regarding biological aberrations that are necessary for the growth and maintenance of these tumors. This has led to the development and initiation of clinical trials incorporating biological treatments for many skull base tumors. The exciting developments of molecularly targeted therapy for the treatment of skull base tumors may provide noninvasive therapeutic options for patients that can be used either alone or in combination with surgery and/or radiation therapy. Future analysis and continued scientific discovery of treatments for skull base tumors can lead to improved outcomes in patients.

Targeted Therapy for Chordoma: Key Molecular Signaling Pathways and the Role of Multimodal Therapy

BACKGROUND

Chordoma is a rare but devastating tumor that arises in the cranial skull base or spine. There are currently no US Food and Drug Administration-approved targeted therapies for chordoma, and little understanding of whether using more than one therapy has benefit over monotherapy.

OBJECTIVE

The objective of this study was to systematically review the current status of clinical trials completed for patients with chordoma to determine if multimodal therapy offers a benefit in progression-free survival over monomodal therapy.

METHODS

We performed a systematic review of the literature according to Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines to review the available clinical trials of targeted therapy for chordoma. We compiled the clinical data to determine if there is a benefit of multimodal therapy over monotherapy.

RESULTS

Our search resulted in 11 clinical trials including 270 patients with advanced chordoma who were treated with targeted therapies. The most commonly employed targeted therapies acted within the following pathways: platelet-derived growth factor receptor (187 patients), vascular endothelial growth factor (66 patients), and mammalian target of rapamycin (43 patients). Reported progression-free survival for included studies ranged from 2.5 to 58 months, with the longest progression-free survival in a trial that included a platelet-derived growth factor receptor inhibitor, nilotinib, and concurrent radiotherapy (58.2 months). There was a higher range of progression-free survival for trials treating patients with multimodal therapy (10.2-14 months vs 2.5-9.2 months, except for a monotherapy trial published in 2020 with a progression-free survival of 18 months), and those published in 2018 or later (14-58.2 months vs 2.5-10.2 months). Only 23% of patients with chordoma in published clinical trials have been treated with multimodal therapy.

CONCLUSIONS

Progression-free survival may be enhanced by the use of targeted therapy with concurrent radiotherapy, use of multimodal therapy, and use of newer targeted therapy. Future clinical trials should consider use of concurrent radiotherapy and multimodal therapy for patients with advanced chordoma.

Chordoma of the sacrum and mobile spine: a narrative review

Chordoma is a notochord-derived primary tumor of the skull base and vertebral column known to affect 0.08 to 0.5 per 100,000 persons worldwide. Patients commonly present with mechanical, midline pain with or without radicular features secondary to nerve root compression. Management of these lesions has classically revolved around oncologic resection, defined by en bloc resection of the lesion with negative margins as this was found to significantly improve both local control and overall survival. With advancement in radiation modalities, namely the increased availability of focused photon therapy and proton beam radiation, high-dose (>50 Gy) neoadjuvant or adjuvant radiotherapy is also becoming a standard of care. At present chemotherapy does not appear to have a role, but ongoing investigations into the ontogeny and molecular pathophysiology of chordoma promise to identify therapeutic targets that may further alter this paradigm. In this narrative review we describe the epidemiology, histopathology, diagnosis, and treatment of chordoma.

Radiotherapy of extraosseous nasopharyngeal chordoma: A case report and literature review

Chordomas are slow-growing aggressive tumors that account for 1-4% of all bone tumors. The anatomical distribution of chordomas includes 50-60% in the sacrococcygeal region, 25-30% in the skull base and 15% in the mobile spine. Virchow was the first to describe and term these tumors as ‘ecchordosis physaliphora’ in 1857, and Muller established their notochordal origin in 1895. Extraosseous chordomas of the nasopharynx are very rare, and they exhibit similarities with other lesions of the nasopharynx, presenting as a soft tissue mass. Gross total resection combined with postoperative radiotherapy offers the best chance of long-term control. We herein present the case of a 63-year-old female patient with complaints of left temporal headaches, dizziness, left nasal obstruction, left maxillary area numbness, left ear hearing loss and swallowing difficulty. Computed tomography imaging examination revealed an 8.2x3.2x5.7-cm space-occupying lesion with central necrosis in the nasopharynx and oropharynx, partially occluding the pharyngeal lumen; the mass had infiltrated the left parapharyngeal space, the left medial and lateral pterygoid muscle and the left parotid gland, with bone erosion of the left mandible. The patient was diagnosed with extraosseous chordoma of the nasopharynx, conventional type, stage IIB. The patient underwent surgery and high-dose radiotherapy and local control of the chordoma was achieved. However, the patient succumbed to a lung metastasis. The details of the case are discussed, and a review of the current medical literature is presented to provide an updated discussion on the current status of nasopharyngeal chordoma research.

Invited Review: Dysregulation of chromatin remodellers in paediatric brain tumours - SMARCB1 and beyond

Mutations in chromatin remodelling genes occur in approximately 25% of all human tumours (Kadoch et al. Nat Genet 45: 592-601, 2013). The spectrum of alterations is broad and comprises single nucleotide variants, insertion/deletions and more complex structural variations. The single most often affected remodelling complex is the SWI/SNF complex (SWItch/sucrose non-fermentable). In the field of paediatric neuro-oncology, the spectrum of affected genes implicated in epigenetic remodelling is narrower with SMARCB1 and SMARCA4 being the most frequent. The low mutation frequencies in many of the SWI/SNF mutant entities underline the fact that perturbed chromatin remodelling is the most salient factor in tumourigenesis and could thus be a potential therapeutic opportunity. Here, I review the genetic basis of aberrant chromatin remodelling in paediatric brain tumours and discuss their impact on the epigenome in the respective entities, mainly medulloblastomas and rhabdoid tumours.

Novel Nomograms as Aids for Predicting Recurrence and Survival in Chordoma Patients: A Retrospective Multicenter Study in mainland China

STUDY DESIGN

A retrospective data analysis was performed.

OBJECTIVE

The aim of this study is to explore the significant prognostic factors and propose new nomograms to facilitate clinical decision-making.

SUMMARY OF BACKGROUND DATA

Chordoma is a rare bone tumor. The clinical features and optimal therapeutic strategies are still uncertain.

METHODS

Chordoma patients treated in four medical centers of mainland China before January 2015 were included. The predictors for local relapse-free survival (LRFS) and overall survival (OS) were identified by the Lasso regression and Cox proportional hazards regression model. Then the nomograms were developed. Their discrimination, calibration, and accuracy were evaluated by the C-index, calibration curve, and receiver operating characteristic curve (ROC), respectively.

RESULTS

A total of 341 patients were identified and full prognostic variable data were available for 276 patients. A total of 179 patients (64.9%) experienced recurrence and 122 patients (44.2%) died of all causes with a median follow-up time of 57.5 (range, 1-325) months. We identified recurrence-relevant factors of tumor size, tumor location, histology subtype and resection method, and death-relevant factors of tumor size, tumor location, resection method, complication, and postoperative recurrence. The constructed LRFS and OS nomograms showed good calibration and discriminative ability (C index 0.79 and 0.76, respectively). The ROCs suggested decent prediction ability with the 5-year area under curve (AUC) value of 0.868 and 0.786, respectively.

CONCLUSION

Based on the multicenter case series of chordoma with a relative long follow-up, we proposed two nomograms to predict the prognosis on the basis of recurrence- and death-relevant factors. These findings could be referenced in the clinical decision-making process and provide additional prognostic information for risk stratification.

LEVEL OF EVIDENCE

4.

Sacral and thoracic chordoma with pulmonary metastases: A case report and review of the literature

Chordoma is a sporadic type of cancer that affects the spine and is particularly challenging to treat due to the paucity of reported cases and scientific literature. In particular, primary chordomas affecting both the sacral and thoracic vertebrae are extremely rare. We herein report a rare case of chordoma in the sacral and thoracic vertebrae with pulmonary metastasis, along with a literature review. The objective of the present study was to explore treatment options and long-term outcomes in patients with metastatic chordoma. Posterior decompression was performed for the thoracic tumor, followed by extended resection of the sacral tumor. The symptoms of the patient were relieved after surgery, and the postoperative Nurick score decreased from grade 3 to grade 2, while the postoperative McCormick score was I. Therefore, complete chordoma excision and internal spinal fixation may effectively reduce tumor recurrence and metastasis.

Image-guided percutaneous cryoablation of unresectable sacrococcygeal chordoma: Feasibility and outcome in a selected group of patients with long term follow-up

BACKGROUND

Chordoma is a rare malignant tumor of the axial skeleton. Percutaneous cryoablation (PCA) is a minimally invasive technique that allows freezing of tumors under imaging control. The purpose of our retrospective study was to investigate the outcome of PCA in a selected cohort of patients with sacrococcygeal chordoma, with a minimum of 5 years follow-up.

MATERIALS AND METHODS

Four patients were treated in 10 sessions. The mean follow-up was 57.3 months. We evaluated the feasibility, the procedure-related complications, the impact on pain control and oncological outcomes.

RESULTS

Freezing of 100% of the tumor volume was possible in 60%. Pain control was not reliably evaluable. Local recurrence occurred in 90% of the treated lesions; the mean time to progression was 8.1 months (range 1.5-16). At last follow-up, one patient had died of the disease, one of another cause and one was receiving the best supportive care. The only patient alive without the disease had received additional carbon-ion radiotherapy. The 5-year survival rate after index PCA was 50%.

CONCLUSION

Complete freezing of the tumor was technically challenging, mainly due to the complex local anatomy. Recurrence occurred in 90% of the lesions treated. PCA should be considered with caution in the curative management of sacrococcygeal chordoma.