Chordoma: A Review and Differential Diagnosis

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.

KIF15 promotes the development and progression of chordoma via activating PI3K-AKT signalling pathway

Aims

Despite its implication in various human cancers, the expression and functional significance of Kinesin family member 15 (KIF15) in chordomas remain unexplored.

Main methods

The evaluation of KIF15 protein levels was conducted through immunohistochemistry (IHC) staining and Western blot analysis. Cell proliferation was quantified using MTT and CCK8 assays, whereas cell migration was examined using wound healing and Transwell assays. Furthermore, flow cytometric analysis was utilized to assess cell apoptosis and the cell cycle. Additionally, in vivo experiments were performed using a mouse xenograft model.

Key findings

Our study revealed significantly higher expression of KIF15 in stage III chordoma tissues compared to stage II tissues. Knockdown of KIF15 led to notable inhibition of cell proliferation and migration, along with enhanced apoptosis and cell cycle arrest. In vivo studies further confirmed the inhibitory effects of KIF15 knockdown on chordoma tumour growth. In terms of mechanism, we identified the involvement of the PI3K-AKT signalling pathway mediated by KIF15 in chordomas. Notably, the anti-tumour effects of KIF15 deficiency on chordomas were partially reversed by the addition of an AKT activator.

Significance

KIF15 promotes chordoma development and progression through the activation of the PI3K-AKT signalling pathway. Thus, targeting KIF15 might be a promising therapeutic strategy for treating chordomas.

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.

Parasagittal resection of multilevel cervical chordoma with autograft duraplasty and unilateral vertebral artery ligation: A case report and literature review

Chordomas are rare tumors and the recommended course of treatment typically entails surgical resection, which presents significant challenges owing to the anatomical location commonly involved and the inherent resistance of these lesions to radiation and chemotherapy. This case report details the experience of a 61-year-old male who underwent a parasagittal resection spanning from C1 to C4. A durotomy was executed to enable en bloc excision of the tumor. Subsequently, a duraplasty procedure was implemented, utilizing autologous muscle fascia grafting. A comprehensive analysis of the pertinent literature was conducted to underscore the key clinical aspects and outcomes related to this topic.

Chordoma: demographics and survival analysis with a focus on racial disparities and the role of surgery, a U.S. population-based study

BACKGROUND

Chordoma is a rare malignant tumor of notochordal origin that may appear anywhere in the axial skeleton from the skull base to the sacrum. This study presents findings from a large database query to highlight the demographic, clinical, and pathological factors, prognosis, and survival of chordomas.

METHODS

The Surveillance, Epidemiology, and End Results (SEER) data based was used to identify patients with a "chordoma" diagnosis from 200 to 2018.

RESULTS

In a total of 1600 cases, the mean age at diagnosis was 54.47 years (standard deviation, SD ± 19.62 years). Most cases were male (57.1%) and white (84.5%). Tumor size was found to be > 4 cm in 26% of cases. Histologically, 33% with known features had well-differentiated Grade I tumors, and 50.2% of the tumors were localized. Metastasis at the time of to the bone, liver, and lung was observed at a rate of 0.5%, 0.1%, and 0.7%, respectively. The most common treatment received was surgical resection (41.3%). The overall 5-year overall survival observed was 39% (confidence interval, CI 95% 37-41; p = 0.05) with patients who received surgery having a 5-year survival rate of 43% (CI 95% 40-46; p = 0.05). Multivariate analysis showed independent factors that contributed to worse prognosis chemotherapy only as a treatment modality and no surgery as a treatment modality.

CONCLUSION

Chordomas are more common in white males and appear between the 5th and 6th decades of life. Factors that contributed to a worse prognosis were Asian, Pacific Islander, American Indian, or Alaska Native races.

Bibliometric Insights in Advances of Chordoma: Global Trends and Research Development in the Last Decade

Chordoma is a rare tumor, but has a serious effect on the quality of life of patients. This study aims to assess the overall knowledge structure and trends in the development of chordoma research using a bibliometric analysis and visualization tool. Research datasets were acquired from the Web of Science. VOS viewer and CiteSpace visualization software were used to demonstrate collaborations and correlations. Annual trends in publications, distribution, H-index status, co-authorship status, and research hotspots were analyzed. A total of 1844 publications from 2012 to 2022 were included. The number of chordoma-related publications increased year by year. The United States contributed the most publications (717) and had the highest total citations (10130) and H-index (50), followed by China. The United States was also the country most frequently involved in international cooperation. The most productive organization involved in chordoma research was Massachusetts General Hospital. World Neurosurgery (114) published the most papers on chordoma. Hornicek FJ was the most productive author over the last decade (41). Initially, diagnosis and the location of onset captured the attention of the research society. Quality of life, risk factors, disability, minimally invasive surgical techniques, molecular targeted therapy, and radiotherapy technology are the research hotspots in recent years. Indeed, this study provides important insights into the overall landscape of chordoma research and also contributes to the further investigation of the international frontier of chordoma.

Predicting overall survival in chordoma patients using machine learning models: a web-app application

OBJECTIVE

The goal of this study was to evaluate the efficacy of machine learning (ML) techniques in predicting survival for chordoma patients in comparison with the standard Cox proportional hazards (CoxPH) model.

METHODS

Using a Surveillance, Epidemiology, and End Results database of consecutive newly diagnosed chordoma cases between January 2000 and December 2018, we created and validated three ML survival models as well as a traditional CoxPH model in this population-based cohort study. Randomly, the dataset was divided into training and validation datasets. Tuning hyperparameters on the training dataset involved a 1000-iteration random search with fivefold cross-validation. Concordance index (C-index), Brier score, and integrated Brier score were used to evaluate the performance of the model. The receiver operating characteristic (ROC) curves, calibration curves, and area under the ROC curves (AUC) were used to assess the reliability of the models by predicting 5- and 10-year survival probabilities.

RESULTS

A total of 724 chordoma patients were divided into training (n = 508) and validation (n = 216) cohorts. Cox regression identified nine significant prognostic factors (p < 0.05). ML models showed superior performance over CoxPH model, with DeepSurv having the highest C-index (0.795) and the best discrimination for 5- and 10-year survival (AUC 0.84 and 0.88). Calibration curves revealed strong correlation between DeepSurv predictions and actual survival. Risk stratification by DeepSurv model effectively discriminated high- and low-risk groups (p < 0.01). The optimized DeepSurv model was implemented into a web application for clinical use that can be found at https://hust-chengp-ml-chordoma-app-19rjyr.streamlitapp.com/ .

CONCLUSION

ML algorithms based on time-to-event results are effective in chordoma prediction, with DeepSurv having the best discrimination performance and calibration.

Small biopsies in the head and neck: Bone and soft tissue

Bone and soft tissue lesions in the head and neck encompass not only a broad morphologic spectrum but also significant inherent clinicopathologic overlap. Epidemiology, radiology, and location - similar to the diagnostic assessment in other sites - are especially important considerations in the context of an established mesenchymal proliferation. Herein, the approach towards diagnosis is stratified by morphology (spindle, sarcomatoid, epithelioid, round cell), cellular lineage (fibroblastic, nerve sheath, rhabdomyogenic), and tumor grade (benign, low- to high-grade malignant) as the basis of further immunohistochemical or molecular investigation.

Squash smear and fine needle aspiration features of conventional chordoma

Chordoma is a rare primary central nervous system tumour of notochordal origin. Proper intraoperative or preoperative diagnosis of this entity is crucial for appropriate surgical management. The most common histopathological subtype is conventional chordoma. Cytological characteristics of this subtype are quite distinctive and the diagnosis can be easily made by cytology. There are two particularly important features that are observed in both squash smear and fine needle aspiration specimens: an abundant myxochondroid stroma and cells with large vacuoles, including physaliferous cells. The main differential diagnosis is conventional chondrosarcoma, but in problematic cases immunohistochemical studies are useful to establish the correct diagnosis.

Imaging of Skull Base Tumors

The skull base provides a platform for supporting the brain while serving as a conduit for major neurovascular structures. In addition to malignant lesions originating in the skull base, there are many benign entities and developmental variants that may simulate disease. Therefore, a basic understanding of the relevant embryology is essential. Lesions centered in the skull base can extend to the adjacent intracranial and extracranial compartments; conversely, the skull base can be secondarily involved by primary extracranial and intracranial disease. CT and MRI are the mainstay imaging methods and are complementary in the evaluation of skull base lesions. Advances in cross-sectional imaging have been crucial in the management of patients with skull base pathology, as this represents a complex anatomical area that is hidden from direct clinical exam. Furthermore, the clinician must rely on imaging studies for therapy planning and to monitor treatment response. It is crucial to have a thorough understanding of skull base anatomy and its various pathologies, as well as to recognize the appearance of treatment-related changes. In this review, we aim to describe skull base tumors and tumor-like lesions in an anatomical compartmental approach and present imaging methods that aid in diagnosis, management, and follow-up.

The role of particle radiotherapy in the treatment of skull base tumors

The skull base is an anatomically and functionally critical area surrounded by vital structures such as the brainstem, the spinal cord, blood vessels, and cranial nerves. Due to this complexity, management of skull base tumors requires a multidisciplinary approach involving a team of specialists such as neurosurgeons, otorhinolaryngologists, radiation oncologists, endocrinologists, and medical oncologists. In the case of pediatric patients, cancer management should be performed by a team of pediatric-trained specialists. Radiation therapy may be used alone or in combination with surgery to treat skull base tumors. There are two main types of radiation therapy: photon therapy and particle therapy. Particle radiotherapy uses charged particles (protons or carbon ions) that, due to their peculiar physical properties, permit precise targeting of the tumor with minimal healthy tissue exposure. These characteristics allow for minimizing the potential long-term effects of radiation exposure in terms of neurocognitive impairments, preserving quality of life, and reducing the risk of radio-induced cancer. For these reasons, in children, adolescents, and young adults, proton therapy should be an elective option when available. In radioresistant tumors such as chordomas and sarcomas and previously irradiated recurrent tumors, particle therapy permits the delivery of high biologically effective doses with low, or however acceptable, toxicity. Carbon ion therapy has peculiar and favorable radiobiological characteristics to overcome radioresistance features. In low-grade tumors, proton therapy should be considered in challenging cases due to tumor volume and involvement of critical neural structures. However, particle radiotherapy is still relatively new, and more research is needed to fully understand its effects. Additionally, the availability of particle therapy is limited as it requires specialized equipment and expertise. The purpose of this manuscript is to review the available literature regarding the role of particle radiotherapy in the treatment of skull base tumors.

Pre-resection Embolization of a Focal Lumbar Chordoma

Chordoma is a slow-growing local invasive tumor with high mortality and recurrence rates after surgical resection. It can affect the clivus and sacrum and rarely involve the lumbar vertebra. There is limited literature research describing lumbar embolization before surgical resection in lumbar chordoma. Thus, this case report describes an atypical patient with chronic lower back pain who presented to the hospital for worsening pain. Radiological images show an aggressive focal lesion at the second lumbar spine extending into the posterior element. The patient underwent lumbar artery embolization before surgical resection. The final pathology diagnosis confirmed a conventional chordoma. Therefore, patients with radiological imaging features of conventional chordoma may benefit from embolization prior to surgical resection to decrease intraoperative bleeding.

Emotional Problems, Quality of Life and Symptom Burden in Patients with Chordoma

Chordomas are very rare malignant bone tumors. Following surgery, their effects on neurological, physical, psychological, social, and emotional functioning are substantial and can have a major impact on a patients' quality of life (QOL). In this survey, we aimed to characterize the postoperation health-related QOL and emotional problem in patients with chordoma using the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire 30 (EORTC QLQ-C30) and Hamilton Depression Rating Scale (HAMD). The cohort included 100 patients who underwent resection surgery between 2014 and 2020. Being single or divorced, living in a rural area, receiving a diagnosis of sacrococcygeal chordoma, Karnofsky performance status (KPS) ≤ 70, and weight loss were associated with increased likelihood of depression (p < 0.05). Patients who were single or divorced, with KPS ≤ 70, and experiencing weight loss had a higher likelihood of a worse QOL (p < 0.05). The uni- and multivariate logistic regression analyses indicated that the KPS level (p = 0.000) and postoperative radiation therapy (p = 0.009) were related to depression; marital status (p = 0.029), KPS level (p = 0.006), and tumor location (p = 0.033) were related to worse QOL. Certain characteristics placed patients with chordoma at increased risk of emotional problems, which are associated with a lowered QOL and a higher symptom burden. Further knowledge regarding emotional problems is key to improving the QOL for patients with chordoma.

Imaging of spinal chordoma and benign notochordal cell tumor (BNCT) with radiologic pathologic correlation

Benign notochordal cell tumor (BNCT) and chordoma are neoplasms of notochordal differentiation. BNCT represents notochordal rests, commonly an incidental lesion present in the spine in 19% of cadaveric specimens. BNCTs are often radiographically occult. CT of BNCT frequently reveals patchy sclerosis between areas of maintained underlying trabeculae. BNCT demonstrates marrow replacement on T1-weighted MR images with high signal intensity on T2-weighting. BNCTs are frequently smaller than 35 mm and lack significant enhancement, bone destruction, cortical permeation, or soft tissue components. Biopsy or surgical resection of BNCT is usually not warranted, although imaging surveillance may be indicated. Chordoma is a rare low-grade locally aggressive malignancy representing 1-4% of primary malignant bone tumors. Chordoma is most frequent between the ages of 50-60 years with a male predilection. Clinical symptoms, while nonspecific and location dependent, include back pain, numbness, myelopathy, and bowel/bladder incontinence. Unfortunately, lesions are often large at presentation owing to diagnosis delay. Imaging of chordoma shows variable mixtures of bone destruction and sclerosis, calcification (50-70% at CT) and large soft tissue components. MR imaging of chordoma reveals multilobulated areas of marrow replacement on T1-weighting and high signal intensity on T2-weighting reflecting the myxoid component within the lesion and areas of hemorrhage seen histologically. Treatment of chordoma is primarily surgical with prognosis related to resection extent. Unfortunately, complete resection is often not possible (21-75%) resulting in high local recurrence incidence (19-75%) and a 5-year survival rate of 45-86%. This article reviews and illustrates the clinical characteristics, pathologic features, imaging appearance spectrum, treatment, and prognosis of BNCT and spinal chordoma.

Targeting mTOR Pathway in PTEN Deleted Newly Isolated Chordoma Cell Line

Chordomas are rare primary malignant tumours of notochordal origin usually arising along the axial skeleton with particular predilection of the skull base and sacrococcygeal region. Albeit usually slow-growing, chordomas can be aggressive mostly depending on their invasive behaviour and according to different histotypes and molecular alterations, including TBXT duplication and SMARCB1 homozygous deletion. Partial or complete PTEN deficiency has also been observed. PTEN is a negative regulator of the Akt/mTOR pathway and hyperactivation of Akt/mTOR in cells lacking PTEN expression contributes to cell proliferation and invasiveness. This pathway is targeted by mTOR inhibitors and the availability of in vitro models of chordoma cells will aid in further investigating this issue. However, isolation and maintenance of chordoma cell lines are challenging and PTEN-deleted chordoma cell lines are exceedingly rare. Hereby, we established and characterized a novel human PTEN-deleted chordoma cell line (CH3) from a primary skull base chordoma. Cells exhibited morphological and molecular features of the parent tumour, including PTEN loss and expression of Brachyury and EMA. Moreover, we investigated the activation of the mTOR pathway and cell response to mTOR inhibitors. CH3 cells were sensitive to Rapamycin treatment suggesting that mTOR inhibitors may represent a valuable option for patients suffering from PTEN-deleted chordomas.

Competing risk nomogram for predicting prognosis of patients with spinal and pelvic chordoma: A SEER-based retrospective study

PURPOSE

Recently, competing risk nomograms were widely applied to predict prognosis in numerous tumors other than chordoma. Here, we aimed to construct and validate a competing-risk-based prognostic nomogram to predict 3- and 5-year cancer-specific death (CSD) in patients with spinal and pelvic chordoma.

METHODS

All chordoma patient data were abstracted from the Surveillance, Epidemiology, and End Results (SEER) resource, and a total of 485 chordoma patients were eventually included in this study. Multivariate competing risk model and multivariate Cox model were used to determine independent prognostic factors, respectively, and the results of the two models were compared. Nomogram was employed to visualize the competing risk model. The discrimination, calibration, and clinical utility of this model were evaluated by Harrell concordance index (C-index), time-dependent receiver operating characteristic (ROC) curves, calibration plots, and decision curve analysis (DCA). Ten-fold cross-validation was further utilized to validate the prognostic nomogram.

RESULTS

Significant prognostic factors affecting CSD were age (P = 0.016), localized involvement (P < 0.0001), and radical resection (P < 0.001) in the multivariate competing risk model. C-indexes were 0.799 and 0.76, and AUC were 0.812 and 0.778 for 3- and 5-year CSD. Calibration plots demonstrated the nomogram was well-fitted, and DCA indicated good clinical utility. The nomogram showed good performance in the 10-fold cross-validation.

CONCLUSION

We successfully built the first competing-risk-based nomogram to predict clinical outcomes in patients with spinal and pelvic chordoma. This well-established nomogram hopes to help clinicians with precise prognostic assessment and thus improve clinical outcomes.

The malignancy of chordomas is enhanced via a circTLK1/miR-16-5p/Smad3 positive feedback axis

CircRNAs play crucial roles in various malignancies via an increasing number of reported regulatory mechanisms, including the classic sponging mechanism between circRNAs and micro RNAs (miRNAs). We performed bioinformatic analyses and identified circTLK1 as a regulator of malignant chordoma progression. Moreover, we observed that circTLK1 showed high expression in chordoma cells and tissues, while circTLK1 interference suppressed chordoma cell proliferation and invasion. In addition, circTLK1 directly interacted with miR-16-5p, which has previously been shown to repress chordoma, and circTLK1 knockdown suppressed Smad3 expression. Chromatin immunoprecipitation sequencing further demonstrated that Smad3 acts as a positive regulator by interacting with TLK1, thereby mediating the circTLK1/miR-16-5p/Smad3 positive feedback axis. Taken together, our findings suggested that the disruption of the circTLK1/miR-16-5p/Smad3 positive feedback pathway, particularly via the Smad3 inhibitor SIS3, could be a promising therapeutic strategy.

Medium to long term follow-up of survival and quality of life in patients with primary tumors of the cervical spine: Experience From a large single center

Objectives

To evaluate the survival and medium to long term health-related quality of life (HRQoL) of patients with primary cervical spinal tumors in a cross-sectional study and to identify any significant associations with demographic or clinical characteristics.

Methods

Patients diagnosed with primary cervical spinal tumors were retrospectively enrolled and their clinical, radiologic, and follow-up data (specifically the EQ-5D questionnaire) were collected. Univariate and multivariate Cox time-dependent regression analyses were performed to examine the significance of certain variables on overall survival. Univariate and multivariate logistic regression analyses were conducted to identify variables significant for overall HRQoL and each dimension of the EQ-5D.

Results

A total of 341 patients were enrolled in the study with a mean follow-up of 70 months. The diagnosis was benign in 246 cases, malignant in 84, and unconfirmed in 11. The 5-year overall survival rate was 86% and the 10-year overall survival rate was 65%. Multivariate analysis suggested that surgical treatment (P = 0.002, hazard ratio [HR] = 0.431, 95% CI. [0.254, 0.729]), benign and malignant tumors [P < 0.001, HR = 2.788, 95% CI. (1.721, 4.516)], tumor and surrounding normal tissue boundary [P = 0.010, HR = 1.950, 95% CI. (1.171, 3.249)], and spinal instability [P = 0.031, HR = 1.731, 95% CI. (1.051, 2.851)] still had significant effects on survival.

Conclusions

In this cross-sectional study, we evaluated the survival period and medium and long-term health-related quality of life of patients with primary tumors of the cervical spine, and analyzed the significant related factors of tumor clinical characteristics. Surgery, myelopathy, malignancy, spinal pain relieved by lying down or supine position, and tumor infiltration on MRI were significant predictors for overall survival. Enneking stage and age were significant predictors for HRQoL.

Endoscopic Endonasal Surgery for Uncommon Pathologies of the Sellar and Parasellar Regions

Endoscopic skull base surgery has become an integral part of the present neurosurgical armamentarium. The pioneering efforts in which the purely endoscopic transsphenoidal approach was introduced have triggered a growing tide of using the endoscopic endonasal procedures for a large variety of skull base lesions. Because of their anatomical peculiarities, lesions of the sellar and parasellar regions lend themselves very well to the endoscopic endonasal approaches. Apart from the common pathological entities, many other less frequent pathologies are encountered in the sellar and parasellar area. In this chapter, we review the surgical technique of the endoscopic endonasal transsphenoidal approach and its extensions applied to a variety of rare and uncommon pathological entities involving the sella turcica and clivus. An overview of these pathological entities is also presented and exemplified.

Prognostic molecular biomarkers in chordomas: A systematic review and identification of clinically usable biomarker panels

Introduction and objective

Despite the improvements in management and treatment of chordomas over time, the risk of disease recurrence remains high. Consequently, there is a push to develop effective systemic therapeutics for newly diagnosed and recurrent disease. In order to tailor treatment for individual chordoma patients and develop effective surveillance strategies, suitable clinical biomarkers need to be identified. The objective of this study was to systematically review all prognostic biomarkers for chordomas reported to date in order to classify them according to localization, study design and statistical analysis.

Methods

Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we systematically reviewed published studies reporting biomarkers that correlated with clinical outcomes. We included time-to-event studies that evaluated biomarkers in skull base or spine chordomas. To be included in our review, the study must have analyzed the outcomes with univariate and/or multivariate methods (log-rank test or a Cox-regression model).

Results

We included 68 studies, of which only 5 were prospective studies. Overall, 103 biomarkers were analyzed in 3183 patients. According to FDA classification, 85 were molecular biomarkers (82.5%) mainly located in nucleus and cytoplasm (48% and 27%, respectively). Thirty-four studies analyzed biomarkers with Cox-regression model. Within these studies, 32 biomarkers (31%) and 22 biomarkers (21%) were independent prognostic factors for PFS and OS, respectively.

Conclusion

Our analysis identified a list of 13 biomarkers correlating with tumor control rates and survival. The future point will be gathering all these results to guide the clinical validation for a chordoma biomarker panel. Our identified biomarkers have strengths and weaknesses according to FDA’s guidelines, some are affordable, have a low-invasive collection method and can be easily measured in any health care setting (RDW and D-dimer), but others molecular biomarkers need specialized assay techniques (microRNAs, PD-1 pathway markers, CDKs and somatic chromosome deletions were more chordoma-specific). A focused list of biomarkers that correlate with local recurrence, metastatic spread and survival might be a cornerstone to determine the need of adjuvant therapies.

A correlation analysis of sacrococcygeal chordoma imaging and clinical characteristics with the prognostic factors

Objective

To investigate the imaging and clinical risk factors related to the postoperative recurrence of sacrococcygeal chordoma.

Methods

63 patients of sacrococcygeal chordoma proved by operation and pathology in our hospital from January 2009 to December 2019 were retrospectively analyzed in the related factors of imaging manifestations, pathological type, and extent of surgical resection. The recurrence of sacrococcygeal chordoma was followed up. Univariate Kaplan-Meier survival analysis and multivariate Cox regression analysis were used to analyze the related factors of recurrence.

Results

On plain radiographs and CT scans, chordoma primarily manifested as osteolytic bone loss and uneven soft tissue mass, with typical calcification or ossification (56.1 percent). Numerous chunk nodules with clearly high signal levels and short signal intervals were seen as the “pebble” in MRI characteristics on T2WI. The follow-up period ranged from 20 to 130 months, with a median time of 47.5 months. There were 14 recurrences (22. 2%) during the follow-up period. 13 patients with recurrence underwent surgery again, and 5 of them recurred after surgery (recurrence time range 3 to 97 months, median 38. 5 months). 6 (42.8%), 8 (57. 1%), and 13 (92. 9%) of the 14 patients with recurrence recurred within 2, 3, and 5 years after surgery, respectively. Univariate Kaplan-Meier survival analysis showed that occurred with local infiltration, Low differentiated chordoma, partial resection had a high postoperative recurrence rate, and all differences were statistically significant (P<0.05). Multi-factor Cox regression analysis showed whether local infiltration occurred and the degree of tumor resection were independent risk factors for tumor recurrence.

Conclusion

Sacrococcygeal chordoma has a high tendency of recurrence, and the likelihood of recurrence is higher in tumor occurred with local infiltration, non-complete tumor resection and low differentiated chordoma, which can be considered to shorten the review cycle and complete tumor resection as much as possible during surgery.

PTEN is recognized as a prognostic-related biomarker and inhibits proliferation and invasiveness of skull base chordoma cells

Objective

This work aimed to examine the function of phosphatase and tensin homologue deleted on chromosome 10 (PTEN) in skull base chordoma (SBC) at the clinical and cellular levels.

Methods

Totally 65 paraffin-embedded and 86 frozen specimens from 96 patients administered surgery were analyzed. Immunohistochemical staining and quantitative real-time polymerase chain reaction were performed, and the associations of PTEN expression with clinical features were assessed. At the cellular level, PTEN was knocked down by the siRNA approach in the UCH-1 cell line, and cell proliferation and invasion were detected by the CCK-8 and migration assays, respectively.

Results

At the protein level, PTEN expression was increased in non-bone-invasive tumor samples in comparison with bone-invasive specimens (p = 0.025), and elevated in soft SBCs in comparison with hard tumors (p = 0.017). Increased PTEN protein expression was associated with decreased risk of tumor progression (p = 0.002; hazard ratio = 0.981, 95% confidence interval: 0.969–0.993). At the gene expression level, the cut-off value was set at 10.5 after ROC curve analysis, and SBC specimens were divided into two groups: PTEN high group, ΔCt value below 10.5; PTEN low group, ΔCt value above 10.5. In multivariate regression analysis of PFS, the risk of tumor progression was increased in PTEN low group tumors in comparison with PTEN high group SBCs (p = 0.006). In the CCK-8 assay, in comparison with control cells, PTEN knockdown cells had increased absorbance, suggesting elevated cell proliferation rate. In the invasion assay, the number of tumor cells penetrating into the lower chamber was significantly increased in the PTEN knockdown group compared with control cells.

Conclusions

Decreased PTEN expression in SBC, at the protein and gene levels, is associated with reduced PFS. PTEN knockdown in chordoma cells led to enhanced proliferation and invasiveness.

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.

Clinical Outcome of Patients with Pelvic and Retroperitoneal Bone and Soft Tissue Sarcoma: A Retrospective Multicenter Study in Japan

Simple Summary

We aimed to clarify the clinical outcomes of patients with pelvic and retroperitoneal bone and soft tissue sarcoma. The 3-year overall survival (OS), local control (LC) rate, and progression-free survival (PFS) were 71.7%, 79.1%, and 48.6%, respectively. The most influential poor prognostic factor for OS was distant metastasis, and for PFS, this was higher age (≥60 years). Larger primary tumor size (≥10 cm) was the only poor prognostic factor for LC. In the histological analysis, osteosarcoma showed significantly worse OS and PFS than other sarcomas in the pelvis and retroperitoneum.

Abstract

This study aimed to retrospectively analyze the clinical outcomes of patients with pelvic and retroperitoneal bone and soft tissue sarcoma (BSTS). Overall, 187 patients with BSTS in the pelvis and retroperitoneal region treated at 19 specialized sarcoma centers in Japan were included. The prognostic factors related to overall survival (OS), local control (LC), and progression-free survival (PFS) were evaluated. The 3-year OS and LC rates in the 187 patients were 71.7% and 79.1%, respectively. The 3-year PFS in 166 patients without any distant metastases at the time of primary tumor diagnosis was 48.6%. Osteosarcoma showed significantly worse OS and PFS than other sarcomas of the pelvis and retroperitoneum. In the univariate analyses, larger primary tumor size, soft tissue tumor, distant metastasis at the time of primary tumor diagnosis, P2 location, chemotherapy, and osteosarcoma were poor prognostic factors correlated with OS. Larger primary tumor size, higher age, soft tissue tumor, chemotherapy, and osteosarcoma were poor prognostic factors correlated with PFS in patients without any metastasis at the initial presentation. Larger primary tumor size was the only poor prognostic factor correlation with LC. This study has clarified the epidemiology and prognosis of patients with pelvic and retroperitoneal BSTS in Japan.

LIM and SH3 protein 1 (LASP1) differentiates malignant chordomas from less malignant chondrosarcomas

PURPOSE

Chordomas are malignant tumors that develop along the neuraxis between skull-base and sacrum. Chondrosarcomas show similarities with chordomas, yet show less malignant behavior. LIM and SH3 protein 1 (LASP1) is a cytoskeletal protein known to promote the malignant behavior of tumors. LASP1 was previously identified as a possibly overexpressed protein in a chordoma proteomics experiment. In this study we compare LASP1 expression in chordoma and chondrosarcoma tissue.

METHODS

Biopsies of primary tumors were collected from surgically treated chordoma (n = 6) and chondrosarcoma (n = 6) patients, flash-frozen upon collection and collectively analyzed for LASP1 RNA (real-time PCR) and protein expression (western blotting). Additionally, tissue micro array (TMA)-based immunohistochemistry was applied to an archive of 31 chordoma and 1 chondrosarcoma specimen.

RESULTS

In chordoma samples, LASP1 mRNA was detected in 4/6 cases and a strong 36 kDa immunoreactive protein band was observed in 4/5 cases. In contrast, 0/6 chondrosarcoma samples showed detectable levels of LASP1 mRNA and only a weak 36 kDa band was observed in 4/5 cases. Immunohistochemical analysis showed LASP1 expression in all chordoma samples, whereas chondrosarcoma specimen did not show immunoreactivity.

CONCLUSION

LASP1 is strongly expressed in the majority of chordoma cases and shows low expression in chondrosarcoma tissue. Since LASP1 is known to function as oncogene and regulate cell proliferation in other tumor types, this study implicates a role for LASP1 in chordoma biology. Further studies are warranted to improve understanding of LASP1's expression and functioning within chordoma, both in vitro and in vivo.