MicroRNA‑1224 inhibits cell proliferation by downregulating CBX3 expression in chordoma

MicroRNAs (miRNAs/miRs) have abnormal expression in numerous tumors and are closely related to tumor development and resistance to radiotherapy and chemotherapy. However, there are few studies assessing the role and mechanism of miRNA in chordoma. The sequencing data of three pairs of chordoma and notochord tissues from the GSE56183 dataset were analyzed in the present study. Cell proliferation was assessed in vitro using Cell Counting Kit-8. Bioinformatics analysis and the dual luciferase reporter assay were used to evaluate the regulatory relationship between miR-1224 and chromobox 3 (CBX3) in chordoma. The results demonstrated that miR-1224 had a significantly lower expression level in chordoma tissues and cell lines. Overexpression of miR-1224 inhibited proliferation in the chordoma cells, while the knockdown of miR-1224 promoted proliferation of the chordoma cells. Bioinformatics analysis and the dual luciferase reporter assay confirmed that CBX3 was a direct target gene of miR-1224 and that miR-1224 induced the proliferation of chordoma cells through the inhibition of CBX3. In summary, miR-1224 reduced the proliferation of chordoma cells through inhibition of CBX3, which provides a theoretical basis for selecting a novel therapeutic target for chordoma.

Predicting the need for occipitocervical fusion for patients with lower clival chordoma: a single-center retrospective study

OBJECTIVE

To assess the impact of tumor extension into the occipital condyle (OC) in lower clival chordoma management and the need for occipito-cervical fusion (OCF).

METHODS

A retrospective analysis was conducted on 35 patients with lower clival chordoma. The preoperative area of the intact OCs, Hounsfield units, and the integrity of the apical ligament and the tectorial membrane were assessed using preoperative imaging.

RESULTS

Seven (20%) patients were in the OCF group. The OCF group exhibited a higher prevalence of preoperative pain in the neck or head (p = 0.006), ligament absence (p = 0.022), and increased propensity for postoperative wound issues (p = 0.022) than the non-OCF group. The OCF group had less intact OCs (p < 0.001) and higher spinal instability neoplastic score (p = 0.002) than the non-OCF group. All patients with intact OCs<60% underwent OCF, and those with OCs≥70% were treated without OCF. Those with OCs between 60% and 69% underwent OCF if the ligaments were eroded, and did not undergo OCF if the ligaments were intact. Treatment strategies varied, with endoscopic endonasal approach (EEA) alone being common. Radiation therapy was administered to 89% of patients. All three patients treated with OCF after tumor resection had wound issues; none treated with OCF before resection had wound issues. None developed atlanto-occipital instability. Survival rates did not significantly differ between groups.

CONCLUSIONS

In the absence of mobility-related neck pain, patients with lower clival chordoma and intact OC≥60%, intact apical ligament, and intact tectorial membrane, may not require OCF.

Characterization of sacral chordoma and differential diagnosis from other sacral malignancy using [18F]FDG PET/CT

2-Deoxy-2-[18F]fluoro-D-glucose ([18F]FDG) positron emission tomography (PET)/computed tomography (CT) is known to be a helpful imaging modality for sacral chordoma, but its detailed characteristics have not been fully described. The purpose of our study was to identify the [18F]FDG PET/CT imaging characteristics of sacral chordoma and compare them with other sacral malignancy. This retrospective study included patients who underwent [18F]FDG PET/CT because of a mass involving the sacrum. Investigated visual findings included visual score and distribution, and semiquantitative parameters measured included standardized uptake values (SUVmax, SUVpeak, SUVmean), tumor-to-liver ratio (TLR), metabolic tumor volume (MTV), total lesion glycolysis (TLG), and tumor size. Comparison studies and receiver operating characteristics (ROC) curve analysis were performed to differentiate between sacral chordoma and other sacral malignancy. Ten patients with sacral chordoma were finally included (M:F = 6:4, median age = 67 yr). On [18F]FDG PET/CT, sacral chordomas presented as a mass with minimal-moderate uptake with a usually heterogenous distribution. Compared with 12 patients with other sacral malignancies (M:F = 4:8, median age 42 yr), sacral chordoma showed a significantly lower TLR (median value 2.1 vs 6.3, P = .021). In ROC curve analysis, TLR showed the largest area under the curve (AUC) of 0.79 (cutoff ≤ 4.0; sensitivity 100.0%, specificity 58.3%; P = .004), and SUVmax showed the second largest AUC of 0.73 (cutoff ≤ 6.9; sensitivity 80.0%, specificity 66.7%; P = .034). [18F]FDG PET/CT of sacral chordoma showed minimal-moderate uptake. The TLR of [18F]FDG PET/CT was significantly lower than that of other sacral malignancy and was the most useful parameter for differentiating sacral chordoma, with the largest AUC. SUVmax could be another helpful semiquantitative parameter.

An experience in treatment of neurologically silent clival chordoma mimicking a nasopharyngeal tumor

Cranial chordoma is a rare neoplasm that is challenging to both diagnose and manage. We present our experience in treating a case of clival chordoma mimicking a nasopharyngeal mass without any signs of cranial deficits or intracranial insult. Management was comprised of endoscopic transnasal debulking surgery followed by radiotherapy. However, we failed to achieve an oncologic outcome due to the development of lethal central nervous system and respiratory infections 1 month after the surgery.

Nasopharyngeal Chordoma: A Case Report

Chordoma is a rare malignant neoplasm arising from remnants of primitive notochord. The most common location for chordoma is in the sacrum. This case presents a 10-year-old medically free male who came to the ENT clinic with the impression of adenoid hypertrophy. After further investigations, including imaging and biopsy, it was found to be a nasopharyngeal chordoma. Our aim, in this case, is to increase the suspension of differential diagnosis of nasopharyngeal masses other than adenoid hypertrophy. In addition, it highlights the importance of imaging in the evaluation of nasopharyngeal masses.

Investigating the Effects of Chordoma Cell-Derived Exosomes on the Tumorigenicity of Nucleus Pulposus Cells

Objective  Interaction of tumor cells with the surrounding environment is essential for tumor growth and progression that eventually leads to metastasis. Growing evidence shows that extracellular vesicles also known as exosomes play a crucial role in signaling between the tumor and its microenvironment. Tumor-derived exosomes have generally protumorigenic effects such as metastasis, hypoxia, angiogenesis, and epithelial-mesenchymal transition. Methods  In this study, exosomes were isolated from a chordoma cell line, MUG-Chor1, and characterized subsequently. The number of exosomes was determined and introduced into the healthy nucleus pulposus (NP) cells for 140 days. The protumorigenic effects of a chordoma cell line-derived exosomes that initiate the tumorigenesis on NP cells were investigated. The impact of tumor-derived exosomes on various cellular events including cell cycle, migration, proliferation, apoptosis, and viability has been studied by treating NP cells with chordoma cell-line-derived exosomes cells. Results  Upon treatment with exosomes, the NP cells not only gained a chordoma-like morphology but also molecular characteristics such as alterations in the levels of certain gene expressions. The migratory and angiogenic capabilities of NP cells increased after treatment with chordoma-derived exosomes. Conclusion  Based on our findings, we can conclude that exosomes carry information from tumor cells and may exert tumorigenic effects on nontumorous cells.

Longitudinal treatment outcomes of recurrent clival chordomas: a single-center retrospective study

OBJECTIVE

The objective of this study was to clarify the detailed clinical course of recurrent clival chordoma and the outcomes of each treatment modality.

METHODS

A single-center retrospective analysis was conducted on patients seen for recurrent clival chordoma. The cohort was identified from those who underwent surgery, stereotactic radiosurgery, or proton therapy at the authors' institution between 1990 and 2022.

RESULTS

A total of 95 recurrences in 40 patients with a median (interquartile range [IQR]) follow-up of 43 (18-79) months were identified. The median (IQR) age at the time of diagnosis was 48 (36-62) years, and 55% of patients were male. Twenty-three patients were treated with surgery followed by adjuvant radiation before the first recurrence. The median (range) number of recurrences per patient was 2 (1-8), and the median (IQR) time to the first recurrence was 29 (9-51) months. The recurrences were treated with one or more of the following therapies: surgery, radiation, systemic therapy, and laser interstitial thermal therapy (LITT). Surgery was performed for 44 recurrences in 25 patients. Radiation was used to treat 42 recurrences in 28 patients. Patients with recurrences treated with surgery plus radiation had the longest progression-free survival (PFS) (median [95% CI] overall survival [OS] 120 [0-245] months, p < 0.01, log-rank test). Patients with recurrences but without prior radiation had longer PFS than those patients with prior radiation. The median (95% CI) OS after the first recurrence was 68 (54-82) months, 5-year OS after the first recurrence was 48%, and 10-year OS was 27%. Multivariate Cox regression analysis showed that mortality after the first recurrence was significantly associated with no adjuvant radiation (HR 0.149, 95% CI 0.038-0.59, p = 0.0067), older age at the time of the first recurrence (HR 1.04, 95% CI 1.01-1.08, p = 0.021), and total number of recurrences (p = 0.032). Seven patients received systemic therapy, and the median (95% CI) OS of these patients since initiation of systemic therapy was 31 (11-51) months. Imatinib and/or nivolumab were used in 6 patients (15%). One patient (3%) was treated with LITT for his fourth recurrence.

CONCLUSIONS

Despite the aggressive nature of recurrent chordoma, 14 of 29 patients (48%) survived for more than 5 years after the initial recurrence using combined therapies. Multiple treatment options may contribute to the long-term survival of patients with this intractable tumor.

Clinical Outcome after Surgical Treatment of Sacral Chordomas: A Single-Center Retrospective Cohort of 27 Patients

Introduction: The aims of our study were (1) to determine disease-specific and disease-free survival after the en-bloc resection of sacral chordomas and (2) to investigate potential risk factors for tumor recurrence and major postoperative wound-related complications. Methods: We retrospectively analyzed 27 consecutive patients with sacral chordomas who were surgically treated in our institution between 2004 and 2022. Three patients (11.1%) had a recurrent tumor and four patients (14.8%) had history of a second primary solid tumor prior to or after their sacral chordoma. A combined anterior and posterior approach, colostomy, plastic reconstruction, and spinopelvic instrumentation were necessitated in 51.9%, 29.6%, 37%, and 7.4% of cases, respectively. The mean duration of follow-up was 58 ± 41 months (range= 12-170). Death-related-to-disease, disease recurrence, and major surgical site complications were analyzed using Kaplan-Meier survival analysis, and investigation of the respective risk factors was performed with Cox hazard regression. Results: The estimated 5-year and 10-year disease-specific survival was 75.3% (95% CI = 49.1-87.5%) and 52.7% (95% CI = 31-73.8%), respectively. The estimated 1-year, 5-year, and 10-year disease-free survival regarding local and distant disease recurrence was 80.4% (95% CI = 60.9-91.1%), 53.9% (95% CI = 24.6-66.3%), and 38.5% (95% CI = 16.3-56.2%), respectively. The mean survival of the recurred patients was 61.7 ± 33.4 months after their tumor resection surgery. Conclusions: Despite the high relapse rates and perioperative morbidity, long-term patient survival is not severely impaired. Positive or less than 2 mm negative resection margins have a significant association with disease progression.

Patterns of Temporal Lobe Reaction and Radiation Necrosis after Particle Radiotherapy in Patients with Skull Base Chordoma and Chondrosarcoma-A Single-Center Experience

BACKGROUND

The current study aims to evaluate the occurrence of temporal lobe reactions and identify possible risk factors for patients who underwent particle therapy of the skull base.

METHODS

244 patients treated for skull base chordoma (n = 144) or chondrosarcoma (n = 100) at the Heidelberg Ion Beam Therapy Center (HIT) using a raster scan technique, were analyzed. Follow-up MRI-scans were matched with the initial planning images. Radiogenic reactions were contoured and analyzed based on volume and dose of treatment.

RESULTS

51 patients with chordoma (35.4%) and 30 patients (30%) with chondrosarcoma experienced at least one temporal lobe reaction within the follow-up period (median 49 months for chondrosarcoma, 62 months for chordoma). Age, irradiated volume, and dose values were significant risk factors for the development of temporal lobe reactions with the highest significance for the value of DMax-7 being defined as the dose maximum in the temporal lobe minus the 7cc with the highest dose (p = 0.000000000019; OR 1.087).

CONCLUSION

Temporal lobe reactions are a common side effect after particle therapy of the skull base. We were able to develop a multivariate model, which predicted radiation reactions with a specificity of 99% and a sensitivity of 52.2%.

A case report of Sustained triumph: 15-year recurrence-free survival following surgical resection of a cervical chordoma in a 15-year-old girl

Introduction and importance

Chordoma of the cervical spine is a rare condition associated with poor long-term outcomes. This is mainly attributed to its pathological involvement of vital structures such as the cervical roots and vertebral artery (VA). Although the most appropriate management in these cases is total en bloc excision, attaining complete resection is relatively challenging due to the vicinity of the critical anatomical structures mentioned above.

Case description

A 15-year-old female with middle cervical spine chordoma was treated by a multidisciplinary team involving neurosurgery and head and neck surgeons utilizing anterior and posterior approaches followed by high-beam X-ray radiotherapy. Histopathological examination matched the description of a chordoma. Fifteen years after the initial excision, the patient maintained her normal neurological function without local recurrence or metastasis.

Clinical discussion

The patient underwent surgery in two stages. A posterior approach for C3, C4, and C5 laminectomies was performed in the first stage, with the second stage involving head and neck surgery for complete resection of the tumor. The patient also underwent radiotherapy 3 months after surgery for a total duration of 1 month. The patient is currently 30 years old with no evidence of chordoma recurrence.

Conclusion

Patients afflicted with cervical chordomas often find themselves undergoing multiple operations due to high recurrence rates. Fortunately, the utilization of en bloc resection coupled with adjuvant radiotherapy presents a hopeful treatment modality that can serve to substantially reduce recurrence rates, increase survival rates, and ultimately enhance the quality of life.

Spinal cord stimulation for chronic pain treatment following sacral chordoma resection: illustrative case

BACKGROUND

Cancer-related or postoperative pain can occur following sacral chordoma resection. Despite a lack of current recommendations for cancer pain treatment, spinal cord stimulation (SCS) has demonstrated effectiveness in addressing cancer-related pain.

OBSERVATIONS

A 76-year-old female with a sacral chordoma underwent anterior osteotomies and partial en bloc sacrectomy. She subsequently presented with chronic pain affecting both buttocks and posterior thighs and legs, significantly impeding her daily activities. She underwent a staged epidural SCS paddle trial and permanent system placement using intraoperative neuromonitoring. The utilization of percutaneous leads was not viable because of her history of spinal fluid leakage, multiple lumbosacral surgeries, and previous complex plastic surgery closure. The patient reported a 62.5% improvement in her lower-extremity pain per the modified Quadruple Visual Analog Scale and a 50% improvement in the modified Pain and Sleep Questionnaire 3-item index during the SCS trial. Following permanent SCS system placement and removal of her externalized lead extenders, she had an uncomplicated postoperative course and reported notable improvements in her pain symptoms.

LESSONS

This case provides a compelling illustration of the successful treatment of chronic pain using SCS following radical sacral chordoma resection. Surgeons may consider this treatment approach in patients presenting with refractory pain following spinal tumor resection.

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.

Immunohistochemical markers predicting recurrence following resection and radiotherapy in chordoma patients: insights from a multicenter study [RETRACTED]

OBJECTIVE

Chordomas are rare tumors that often recur regardless of surgery with negative margins and postoperative radiotherapy. The predictive accuracy of widely used immunohistochemical (IHC) markers in addressing the recurrence of skull base chordomas (SBCs) is yet to be determined. This study aimed to investigate IHC markers in the prediction of recurrence after SBC resection with adjuvant radiation therapy.

METHODS

The authors reviewed the records of patients who had treatment for SBC between January 2017 and June 2021 across the Mayo Clinic in Minnesota, Florida, and Arizona. Exclusion criteria included patients who had no histopathology or recurrence as an outcome. Histopathological markers included cytokeratin A1/A3 only, epithelial membrane antigen (EMA), S100 protein, pan-cytokeratin, IN1, GATA3, CAM5.2, OSCAR, and chondroid. Information from patient records was abstracted, including treatment, clinical and radiological follow-up duration, demographics, and histopathological factors. Decision tree and random forest classifiers were trained and tested to predict the recurrence based on unseen data using an 80/20 split.

RESULTS

A total of 38 patients with a diagnosis of SBC who underwent resection (gross-total resection: 42.1%; and subtotal resection: 57.9%) and radiation therapy were extracted from the medical records. The mean patient age was 48.2 (SD 19.6) years; most patients were male (n = 23; 60.5%) and White (n = 36; 94.7%). Pan-cytokeratin was associated with an increased risk of postoperative recurrence (OR 14.67, 95% CI 2.44-88.13; p = 0.00517) after resection and adjuvant radiotherapy. The decision tree analysis found pan-cytokeratin-positive tumors to have a 78% chance of being classified as a recurrence, with an accuracy of 75%. The distribution of minimal depth in the prediction of postoperative recurrence indicates that the most important variables were pan-cytokeratin, followed by cytokeratin A1/A3 and EMA.

CONCLUSIONS

The authors' machine learning algorithm identified pan-cytokeratin as the largest contributor to recurrence among other IHC markers after SBC resection. Machine learning may facilitate the prediction of outcomes in rare tumors, such as chordomas.

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.

Risk factors for sacral fracture following en bloc chordoma resection

OBJECTIVE

The purpose of this study was to analyze risk factors for sacral fracture following noninstrumented partial sacral amputation for en bloc chordoma resection.

METHODS

A multicenter retrospective chart review identified patients who underwent noninstrumented partial sacral amputation for en bloc chordoma resection with pre- and postoperative imaging. Hounsfield units (HU) were measured in the S1 level. Sacral amputation level nomenclature was based on the highest sacral level with bone removed (e.g., S1 foramen amputation at the S1-2 vestigial disc is an S2 sacral amputation). Variables collected included basic demographics, patient comorbidities, surgical approach, preoperative radiographic details, neoadjuvant and adjuvant radiation therapy, and postoperative sacral fracture data.

RESULTS

A total of 101 patients (60 men, 41 women) were included; they had an average age of 69 years, BMI of 29 kg/m2, and follow-up of 60 months. The sacral amputation level was S1 (2%), S2 (37%), S3 (44%), S4 (9%), and S5 (9%). Patients had a posterior-only approach (77%) or a combined anterior-posterior approach (23%), with 10 patients (10%) having partial sacroiliac (SI) joint resection. Twenty-seven patients (27%) suffered a postoperative sacral fracture, all occurring between 1 and 7 months after the index surgery. Multivariable logistic regression analysis demonstrated S1 or S2 sacral amputation level (p = 0.001), combined anterior-posterior approach (p = 0.0064), and low superior S1 HU (p = 0.027) to be independent predictors of sacral fracture. The fracture rate for patients with superior S1 HU < 225, 225-300, and > 300 was 38%, 15%, and 9%, respectively. An optimal superior S1 HU cutoff of 300 was found to maximize sensitivity (89%) and specificity (42%) in predicting postamputation sacral fracture. In addition, the fracture rate for patients who underwent partial SI joint resection was 100%.

CONCLUSIONS

Patients with S1 or S2 partial sacral amputations, a combined anterior-posterior surgical approach, low superior S1 HU, and partial SI joint resection are at higher risk for postoperative sacral fracture following en bloc chordoma resection and should be considered for spinopelvic instrumentation at the index procedure.

Association between immunohistochemical markers and tumor progression following resection of spinal chordomas: a multicenter study

OBJECTIVE

Chordomas are slow-growing tumors derived from notochord remnants. Despite margin-negative excision and postoperative radiation therapy, spinal chordomas (SCs) often progress. The potential of immunohistochemical (IHC) markers, such as epithelial membrane antigen (EMA), combined with machine learning algorithms to predict long-term (≥ 12 months) postoperative tumor progression, has been understudied. The authors aimed to identify IHC markers using trained tree-based algorithms to predict long-term (≥ 12 months) postoperative tumor progression.

METHODS

The authors reviewed the records of patients who underwent resection of SCs between January 2017 and June 2021 across the Mayo Clinic enterprise. Demographics, type of treatment, histopathology, and other relevant clinical factors were abstracted from each patient's record. Low tumor progression was defined as more than a 94.3-mm3 decrease in the tumor size at the latest radiographic follow-up. Decision trees and random forest classifiers were trained and tested to predict the long-term volumetric progression after an 80/20 data split.

RESULTS

Sixty-two patients diagnosed with and surgically treated for SC were identified, of whom 31 were found to have a more advanced tumor progression based on the tumor volume change cutoff of 94.3 mm3. The mean age was 54.3 ± 13.8 years, and most patients were male (62.9%) and White (98.4%). The most common treatment modality was subtotal resection with radiation therapy (35.5%), with proton beam therapy being the most common (71%). Most SCs were sacrococcygeal (41.9%), followed by cervical (32.3%). EMA-positive SCs had a postoperative progression risk of 67%. Pancytokeratin-positive SCs had a progression rate of 67%; however, patients with S100 protein-positive SCs had a 54% risk of progression. The accuracy of this model in predicting the progression of unseen test data was 66%. Pancytokeratin (mean minimal depth = 1.57), EMA (mean minimal depth = 1.58), cytokeratin A1/A3 (mean minimal depth = 1.59), and S100 protein (mean minimal depth = 1.6) predicted the long-term volumetric progression. Multiway variable importance plots show the relative importance of the top 10 variables based on three measures of varying significance and their predictive role.

CONCLUSIONS

These IHC variables with tree-based machine learning tools successfully demonstrate a high capacity to identify a patient's tumor progression pattern with an accuracy of 66%. Pancytokeratin, EMA, cytokeratin A1/A3, and S100 protein were the IHC drivers of a low tumor progression. This shows the power of machine learning algorithms in analyzing and predicting outcomes of rare conditions in a small sample size.

A Rare Case of Benign Long-Standing Ecchordosis Physaliphora

Ecchordosis physaliphora (EP) is a rare benign lesion arising from embryonic notochordal remnants, typically located in the retroclival region. This case report presents a 46-year-old male patient experiencing intermittent headaches and occipital pain. Imaging revealed a well-defined, smoothly corticated bony lesion on the left side of the clivus, accompanied by a characteristic bony stalk devoid of any aggressive features. A review of the patient's medical records indicated stable imaging findings of the lesion over six years. Clinicians and radiologists should be familiar with EP as a benign entity and differentiate it from aggressive pathologies.

The mutational landscape of skull base and spinal chordomas and the identification of potential prognostic and theranostic biomarkers

OBJECTIVE

Chordomas are rare bone neoplasms characterized by a high recurrence rate and no benefit from any approved medical treatment to date. However, the investigation of molecular alterations in chordomas could be essential to prognosticate, guide clinical decision-making, and identify theranostic biomarkers. The aim of this study was to provide a detailed genomic landscape of a homogeneous series of 64 chordoma samples, revealing driver events, theranostic markers, and outcome-related genomic features.

METHODS

The authors conducted whole-exome sequencing (WES), targeted next-generation sequencing, and RNA sequencing of 64 skull base and spinal chordoma samples collected between December 2006 and September 2020. Clinical, histological, and radiological data were retrospectively analyzed and correlated to genetic findings.

RESULTS

The authors identified homozygous deletions of CDKN2A/2B, PIK3CA mutations, and alterations affecting genes of SWI/SNF chromatin remodeling complexes (PBRM1 and ARID1A) as potential theranostic biomarkers. Using matched germline WES, they observed a higher frequency of a common genetic variant (rs2305089; p.(Gly177Asp)) in TBXT (97.8%, p < 0.001) compared to its distribution in the general population. PIK3CA mutation was identified as an independent biomarker of short progression-free survival (HR 10.68, p = 0.0008). Loss of CDKN2A/2B was more frequently observed in spinal tumors and recurrent tumors.

CONCLUSIONS

In the current study, the authors identified driver events such as PBRM1 and PIK3CA mutations, TBXT alterations, or homozygous deletions of CDKN2A/2B, which could, for some, be considered potential theranostic markers and could allow for identifying novel therapeutic approaches. With the aim of a future biomolecular prognostication classification, alterations affecting PIK3CA and CDKN2A/2B could be considered as poor prognostic biomarkers.

Carbon Ion Radiotherapy: An Evidence-Based Review and Summary Recommendations of Clinical Outcomes for Skull-Base Chordomas and Chondrosarcomas

Skull-base chordoma and chondrosarcoma are rare radioresistant tumors treated with surgical resection and/or radiotherapy. Because of the established dosimetric and biological benefits of heavy particle therapy, we performed a systematic and evidence-based review of the clinical outcomes of patients with skull-base chordoma and chondrosarcoma treated with carbon ion radiotherapy (CIRT). A literature review was performed using a MEDLINE search of all articles to date. We identified 227 studies as appropriate for review, and 24 were ultimately included. The published data illustrate that CIRT provides benchmark disease control outcomes for skull-base chordoma and chondrosarcoma, respectively, with acceptable toxicity. CIRT is an advanced treatment technique that may provide not only dosimetric benefits over conventional photon therapy but also biologic intensification to overcome mechanisms of radioresistance. Ongoing research is needed to define the magnitude of benefit, patient selection, and cost-effectiveness of CIRT compared to other forms of radiotherapy.

Unravelling the role of immune cells and FN1 in the recurrence and therapeutic process of skull base chordoma

BACKGROUND

Skull base chordoma is a rare and aggressive tumour of the bone that has a high likelihood of recurrence. The fundamental differences in single cells between primary and recurrent lesions remain poorly understood, impeding development of effective treatment approaches.

METHODS

To obtain an understanding of the differences in single cells between primary and recurrent chordomas, we performed single-cell RNA sequencing and T-cell/B-cell receptor (BCR) sequencing. This allowed us to delineate the differences between the two types of tumour cells, tumour-infiltrating lymphocytes, myeloid cells, fibroblasts and B cells. Copy number variants (CNVs) were detected and compared between the tumour types to assess heterogeneity. Selected samples were subjected to immunohistochemistry to validate protein expression. Fluorescence in situ hybridisation experiments, Transwell assays and xenograft mouse models helped verify the role of fibronectin 1 (FN1) in chordoma.

RESULTS

Promoting natural killer (NK) cell and CD8_GZMK T-cell function or inhibiting the transformation of CD8_GZMK T cells to CD8_ZNF683 T cells and promoting the transformation of natural killer T (NKT) cells to NK cells are promising strategies for preventing chordoma recurrence. Additionally, inhibiting the M2-like activity of tumour-associated macrophages (TAMs) could be an effective approach. Antigen-presenting cancer-associated fibroblasts (apCAFs) and dendritic cells (DCs) with high enrichment of the antigen-presenting signature were enriched in primary chordomas. There were fewer plasma cells and BCR clonotypes in recurrent chordomas. Remarkably, FN1 was upregulated, had more CNVs, and was more highly secreted by tumours, macrophages, CD4 T cells, CD8 T cells and fibroblasts in recurrent chordoma than in primary chordoma. Finally, FN1 enhanced the invasion and proliferation of chordomas in vivo and in vitro.

CONCLUSION

Our comprehensive picture of the microenvironment of primary and recurrent chordomas provides deep insights into the mechanisms of chordoma recurrence. FN1 is an important target for chordoma therapy.

Multifocal Ectopic Recurrence of a C2 Chordoma

Background  Chordomas are histologically benign but locally aggressive tumors with a high propensity to recur. Our case highlights the importance of long-term vigilance in patients who have undergone chordoma resection. Case Report  We report the case of a 47-year-old man with a cervical chordoma who developed multiple musculoskeletal ectopic recurrences in the left supraclavicular region, the proximal right bicep, and the left submandibular region without recurrence in the primary tumor site. Primary tumor resection was achieved via a combination of surgery, adjuvant radiation therapy, and imatinib. All recurrences were successfully resected and confirmed via pathology to be ectopic chordoma. Discussion  Ectopic recurrence of cervical chordoma is rare and lung is the most common site of distant spread. Chordoma recurrence in skeletal muscle is particularly rare, with only 10 cases described in the literature. A plausible mechanism of distant metastatic disease in chordoma patients suggests that tumor cells escape the surgical tract via a combination of cytokine release, vasodilation, and microtrauma induced during resection. Conclusion  Cervical chordoma with ectopic recurrence in skeletal muscle has not been previously described in the literature. Skull base surgeons should be aware of the phenomenon of chordoma ectopic recurrence in the absence of local recurrence.

An Ecchordosis Physaliphora, a Rare Entity, Involving the Central Nervous System: A Systematic Review of the Literature

Ecchordosis physaliphora (EP) is a benign notochordal remnant, which is often an incidental finding; however, it can rarely present with neurological symptoms. We performed a systematic review of the literature for cases of symptomatic EP published in PubMed, Web of Science and Embase from January 1982 to May 2023. This is the largest review to date and revealed 60 cases including ours. Headache (55%) and CSF rhinorrhea (32%) were the most frequent clinical manifestations. The majority of symptomatic EP lesions were located in the prepontine region (77%) and required surgical resection (75%). EP should be considered in patients with neurologic symptoms in the setting of prepontine or posterior sphenoid sinus lesions. While symptomatic patients often require surgical intervention, rare cases may respond to oral corticosteroids.

The role of tumor immune microenvironment in chordoma: promising immunotherapy strategies

Chordoma is a rare malignant bone tumor with limited therapeutic options, which is resistant to conventional chemotherapy and radiotherapy, and targeted therapy is also shown with little efficacy. The long-standing delay in researching its mechanisms of occurrence and development has resulted in the dilemma of no effective treatment targets and no available drugs in clinical practice. In recent years, the role of the tumor immune microenvironment in driving tumor growth has become a hot and challenging topic in the field of cancer research. Immunotherapy has shown promising results in the treatment of various tumors. However, the study of the immune microenvironment of chordoma is still in its infancy. In this review, we aim to present a comprehensive reveal of previous exploration on the chordoma immune microenvironment and propose promising immunotherapy strategies for chordoma based on these characteristics.

Radiotherapy after gross-total resection and subtotal resection of spinal chordoma: a SEER database analysis of overall survival outcomes

OBJECTIVE

Chordomas are most frequently found in the sacrum, vertebral column, and skull base. Achieving gross-total resection (GTR) has been shown to optimize overall survival (OS); however, the efficacy of radiotherapy (RT) for patients with GTR is currently not well understood. Given that RT may negatively impact patient quality of life, the aim of this study was to evaluate the utility of RT for improving OS in patients who have undergone GTR of spinal chordoma through analysis of the national Surveillance, Epidemiology, and End Results (SEER) database.

METHODS

The SEER database (1975-2018) was queried for all adult patients (≥ 21 years) who underwent GTR for spinal chordoma. Bivariate analysis was conducted using chi-square testing for categorical variables, and the log-rank test was performed to find the associations of clinical variables with OS. Cox proportional hazards models were generated for multivariate analyses of the associations among clinical variables and OS.

RESULTS

A total of 263 spinal chordomas that underwent GTR were identified. The mean age of all included patients was 58.72 years, and 63.9% of patients were male. In addition, 0.4% had dedifferentiated histology. The mean follow-up was 75.54 months. Of all patients, 152 (57.8%) received no RT and 111 (42.2%) received RT. Patients with sacral tumor location (80.9% vs 51.4%, p < 0.001) were more likely not to undergo RT when compared to patients with vertebral column location. In multivariate analysis, only age ≥ 65 years was associated with poorer OS (HR 3.16, CI 1.54-5.61, p < 0.001). RT did not have a statistically significant association with OS.

CONCLUSIONS

RT after GTR of chordoma did not improve OS among SEER chordoma patients to a value that achieved statistical significance. Additional multicenter prospective studies are needed to determine the true efficacy of RT after GTR of spinal chordoma.

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.

A rare case of multifocal chordoma involving the lower clivus and multiple spine levels: illustrative case

BACKGROUND

Chordomas are rare bone tumors originating from notochord remnants with a predilection for the median axis of the body, primarily in the sacrococcygeal spine, skull base, and cervical spine. This paper presents the first reported case of simultaneous multilevel chordomas with various enhancements.

OBSERVATIONS

A 40-year-old woman presented with right-sided otalgia, headache, nasal obstruction, and facial pressure. The patient's head and spinal magnetic resonance imaging (MRI) demonstrated a midline lesion in the clivus, C2, and T1-5 spinal levels. All lesions were T1 isointense and T2 hyperintense, consistent with chordoma. Interestingly, the clivus lesion was enhancing, whereas the C2 lesion was only slightly enhancing, and the rest of the lesions showed no enhancement. The patient underwent endoscopic endonasal transclival approach surgery for the clival lesion, followed by radiation to the surgical bed and the C2 lesion. The remaining lesions were monitored. Follow-up imaging showed stable disease in the C2 lesion and other lower lesions. The patient's severe pain in the posterior cervical spine was managed with cervical fusion, pain management, and physical therapy.

LESSONS

This case underscores the importance of comprehensive spinal MRI in patients with chordomas, as multiple concurrent primaries may be present. The article summarizes the fundamental distinctions between ecchordosis physaliphora and chordoma and casts doubt on the capacity to always differentiate them.

Survey of Palliative Care Use in Primary Malignant Bone Tumors: A National Cancer Database Review

Background/Objectives: Palliative care (PC) has been associated with reduced patient symptom burden, improved physician satisfaction, and reduced cost of care. However, its use in primary bone tumors has not been well classified. Design/Setting and Subjects: Patients diagnosed with primary malignant bone tumors (osteosarcoma, chondrosarcoma, Ewing sarcoma, and chordoma) between 2004 and 2018 were identified in the National Cancer Database. Cross tabulations with chi-square analysis were performed to evaluate frequencies of PC use by patient, facility, and tumor characteristics. Multivariate logistic binary regression was performed to evaluate relationships between patient, treatment facility, and tumor characteristics and the use of PC. Results: Around 24,401 patients were identified. Overall, 2.52% had any form of PC utilization. Of those receiving PC, 55.5-65.1% were treated with only noncurative surgery, radiation, chemotherapy, or any combination of these modalities. Odds of PC utilization were decreased for patients with chordomas, patients living >24 miles from the treatment facility, or patients with private insurance, Medicare, or unknown insurance status. Odds of PC utilization were increased in patients with greater tumor diameter or unknown tumor size, tumors in midline, increased tumor grade, stage IV tumors, or living in urban areas. Conclusion: PC use in patients with primary bone tumors increases with tumor stage, tumor grade, tumor size, and if the tumor is midline, and in patients living in urban areas. However, overall utilization remains markedly low. Future studies should be done to investigate these patterns of care and help expand the utilization of PC.

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.

METHOD

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.

Bilateral Inferior Turbinate Flaps for Salvage Reconstruction after Proton Beam Radiotherapy for Clival Chordoma

Clival chordoma is a rare, aggressive, notochord-derived tumor primarily managed with surgery via an endoscopic endonasal approach (EEA) and adjuvant proton beam radiotherapy. Reconstruction is commonly performed with a nasoseptal flap (NSF) at the time of initial surgery. While failures of the NSF are rare, they can occur following the initial surgery or in the setting of osteoradionecrosis. Salvage repair typically requires transfer of alternative vascularized tissues outside of the previously radiated field including regional scalp flaps such as pericranial or temporoparietal fascial flaps, or free vascularized tissue transfer. Here we describe the case of a 29-year-old woman with a history of clival chordoma with widespread skull base osteomyelitis secondary to NSF necrosis after proton beam radiotherapy. We describe successful skull base reconstruction with intranasal bilateral inferior turbinate flaps based on the sphenopalatine artery with lateral nasal wall extension, despite prior proton beam therapy and a failed prior vascularized intranasal reconstruction.

Outcomes of Endoscopic Resection in Pediatric Skull Base Chordoma: A Systematic Review

The endoscopic approach has been recommended as a primary option for treating chordomas, and it is associated with better resection rates and fewer surgical complications than transcranial surgery. This review aimed to assess the long-term consequences and evidence in the current literature regarding the endoscopic approach's efficacy in treating skull-base chordoma in children. A systematic review was conducted based on the PubMed, Web of Science, and EMBASE databases to examine the clinical outcomes of endoscopic endonasal surgery for pediatric skull base chordoma tumors. The review included studies published in English that employed specific research designs and reported on pediatric patients with skull base chordoma. Of the 268 studies initially considered, 25 met our eligibility criteria and were included in the final analysis. The average age of the patients was 11.5 years, with approximately equal number of males and females. The endoscopic endonasal approach (EEA) was the most commonly used modality. Gross total resection (GTR) was achieved in 62.7% of patients, while 18.09% had a subtotal resection (STR), and 13.83% had near-total resection only. Most patients showed significant to moderate improvement from their baseline condition and had no recurrence during their follow-up. Our findings further endorse that the endoscopic approach is a viable primary treatment option for pediatric skull base chordoma.

SMARCB1/INI1 loss in skull base conventional chordomas: a clinicopathological and molecular analysis

Introduction

The loss of SMARCB1/INI1 protein has been recently described in poorly differentiated chordoma, an aggressive and rare disease variant typically arising from the skull base.

Methods

Retrospective study aimed at 1) examining the differential immunohistochemical expression of SMARCB1/INI1 in conventional skull base chordomas, including the chondroid subtype; 2) evaluating SMARCB1 gene deletions/copy number gain; and 3) analyzing the association of SMARCB1/INI1 expression with clinicopathological parameters and patient survival.

Results

65 patients (35 men and 30 women) affected by conventional skull base chordoma, 15 with chondroid subtype, followed for >48 months after surgery were collected. Median age at surgery was 50 years old (range 9-79). Mean tumor size was 3.6 cm (range 2-9.5). At immunohistochemical evaluation, a partial loss of SMARCB1/INI1 (>10% of neoplastic examined cells) was observed in 21 (32.3%) cases; the remaining 43 showed a strong nuclear expression. Fluorescence in situ hybridization (FISH) analysis was performed in 15/21 (71.4%) cases of the chordomas with partial SMARCB1/INI1 loss of expression. Heterozygous deletion of SMARCB1 was identified in 9/15 (60%) cases and was associated to copy number gain in one case; no deletion was found in the other 6 (40%) cases, 3 of which presenting with a copy number gain. No correlations were found between partial loss of SMARCB1/INI1 and the clinicopathological parameters evaluated (i.e., age, tumor size, gender, tumor size and histotype). Overall 5-year survival and 5-year disease-free rates were 82% and 59%, respectively. According to log-rank test analysis the various clinico-pathological parameters and SMARCB1/INI1 expression did not impact on overall and disease free-survival.

Discussion

Partial loss of SMARCB1/INI1, secondary to heterozygous deletion and/or copy number gain of SMARCB1, is not peculiar of aggressive forms, but can be identified by immunohistochemistry in a significant portion of conventional skull base chordomas, including the chondroid subtype. The variable protein expression does not appear to correlate with clinicopathological parameters, nor survival outcomes, but still, it could have therapeutic implications.

SRY-box Transcription Factor 6 Is Expressed Not Only in the Dorsal but Also in the Ventral Zone of the Neural Tube and Is Highly Expressed in the Notochord and Chordoma

In the course of SRY-box transcription factor 6 (SOX6) expression profiling in human embryonic tissue, SOX 6 was found to be highly expressed in the notochord, based on the findings of immunohistochemistry (IHC). Sox6 is also expressed in the neural tube and the distribution of SOX6 is located in the ventral and dorsal zones of the neural tube. In contrast to the findings that SOX6-positive cells were located on the floor plate of the neural tube, OLIG2- and NKX2.2-expressing cells were lacking on the floor plate of the neural tube, and their expression was restricted only to the ventral zone of the neural tube. The expression patterns of SOX9 were similar to those of OLIG2 and NKX2.2 in the neural tube. NKX2.2 and OLIG2 are not expressed in the notochord, but SOX9 and SOX6 are. Because Sox6 is highly expressed in the notochord, the present study investigated whether or not SOX6 is an immunohistochemical marker for the pathologic diagnosis of chordoma, a neoplasm derived from the notochord. IHC revealed that chordoma was strongly positive for SOX6 in two cases of chordoma, one of which occurred in the sacrococcygeal region and another that developed at the base of the skull, suggesting that SOX6 is a useful marker for the histopathologic diagnosis of chordoma.

Intensity-modulated radiotherapy for the management of primary and recurrent chordomas: a retrospective long-term follow-up study

Background

Chordomas have a high risk of recurrence. Radiotherapy (RT) is required as adjuvant therapy after resection. Sufficient radiation doses for local control (LC) can be achieved using either particle therapy, if this technology is available and feasible, or intensity-modulated radiotherapy.

Materials and methods

57 patients (age, 11.8-81.6 years) with chordomas of the skull base, spine and pelvis who received photon radiotherapy between 1995 and 2017 were enrolled in the study. Patients were treated at the time of initial diagnosis (68.4%) or during recurrence (31.6%). 44 patients received adjuvant radiotherapy and 13 received definitive radiotherapy. The median total dose to the physical target volume was 70 Gy equivalent dose in 2 Gy fractions (EQD2) (range: 54.7-82.5) in 22-36 fractions.

Results

LC was 76.4%, 58.4%, 46.7% and 39.9% and overall survival (OS) was 98.3%, 89%, 76.9% and 47.9% after 1, 3, 5 and 10 years, respectively, with a median follow-up period of 6.5 years (range, 0.5-24.3 years). Age, dose and treatment concept (post-operative or definitive) were significant prognostic factors for OS. Primary treatment, macroscopic tumour at RT and size of the irradiated volume were statistically significant prognostic factors for LC.

Conclusion

Photon treatment is a safe and effective treatment for chordomas if no particle therapy is available. The best results can be achieved against primary tumours if the application of curative doses is possible due to organs at risk in direct proximity. We recommend high-dose radiotherapy, regardless of the resection status, as part of the initial treatment of chordoma, using the high conformal radiation technique if particle therapy is not feasible.

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.

Intradural Chordoma Mimicking an Epidermoid Cyst on Imaging

Chordomas are rare, locally aggressive, primary bone tumors derived from primitive notochord remnants. They almost always arise within the axial skeleton, particularly in the skull base and the sacrococcygeal region. They usually present as extradural tumors, but rarely, they present as entirely intradural tumors. This report describes a case of intradural chordoma that mimicked an epidermoid cyst. A 72-year-old woman was incidentally found to have a prepontine extra-axial mass on magnetic resonance imaging. The mass gradually increased in size, and she felt discomfort in the right cheek area. The mass showed similar signal intensity to cerebrospinal fluid on T1-weighted images and T2-weighted images, but high signal intensity on fluid-attenuated inversion recovery images and diffusion-weighted images. Because the presence of very faint contrast enhancement was not noticed, the mass was preoperatively diagnosed as an epidermoid cyst. Tumor resection was performed, and the histopathological diagnosis was chondroid chordoma. Since intradural chordoma may resemble an epidermoid cyst on imaging, radiologists should check carefully for the presence of contrast enhancement and suggest the possibility of intradural chordoma.

Immunohistochemical markers predicting long-term recurrence following clival and spinal chordoma resection: a multicenter study

OBJECTIVE

Chordomas are rare tumors from notochordal remnants and account for 1%-4% of all primary bone malignancies, often arising from the clivus and sacrum. Despite margin-negative resection and postoperative radiotherapy, chordomas often recur. Further, immunohistochemical (IHC) markers have not been assessed as predictive of chordoma recurrence. The authors aimed to identify the IHC markers that are predictive of postoperative long-term (≥ 1 year) chordoma recurrence by using trained multiple tree-based machine learning (ML) algorithms.

METHODS

The authors reviewed the records of patients who had undergone treatment for clival and spinal chordomas between January 2017 and June 2021 across the Mayo Clinic enterprise (Minnesota, Florida, and Arizona). Demographics, type of treatment, histopathology, and other relevant clinical factors were abstracted from each patient record. Decision tree and random forest classifiers were trained and tested to predict long-term recurrence based on unseen data using an 80/20 split.

RESULTS

One hundred fifty-one patients diagnosed and treated for chordomas were identified: 58 chordomas of the clivus, 48 chordomas of the mobile spine, and 45 chordomas sacrococcygeal in origin. Patients diagnosed with cervical chordomas were the oldest among all groups (58 ± 14 years, p = 0.009). Most patients were male (n = 91, 60.3%) and White (n = 139, 92.1%). Most patients underwent resection with or without radiation therapy (n = 129, 85.4%). Subtotal resection followed by radiation therapy (n = 51, 33.8%) was the most common treatment modality, followed by gross-total resection then radiation therapy (n = 43, 28.5%). Multivariate analysis showed that S100 and pan-cytokeratin are more likely to predict the increase in the risk of postoperative recurrence (OR 3.67, 95% CI 1.09-12.42, p= 0.03; and OR 3.74, 95% CI 0.05-2.21, p = 0.02, respectively). In the decision tree analysis, a clinical follow-up > 1897 days was found in 37% of encounters and a 90% chance of being classified for recurrence (accuracy = 77%). Random forest analysis (n = 500 trees) showed that patient age, type of surgical treatment, location of tumor, S100, pan-cytokeratin, and EMA are the factors predicting long-term recurrence.

CONCLUSIONS

The IHC and clinicopathological variables combined with tree-based ML tools successfully demonstrated a high capacity to identify recurrence patterns with an accuracy of 77%. S100, pan-cytokeratin, and EMA were the IHC drivers of recurrence. This shows the power of ML algorithms in analyzing and predicting outcomes of rare conditions of a small sample size.

Primary Osseous Malignancies of the Spine

Malignant primary vertebral tumours comprise an uncommon group of primary bone malignancies that can pose a diagnostic and therapeutic challenge. The most frequently encountered malignant primary vertebral tumours include chordoma, chondrosarcoma, Ewing sarcoma and osteosarcoma. These tumours often present with nonspecific symptoms, such as back pain, neurologic deficits and spinal instability, which can be confused for the more commonly encountered mechanical back pain and may delay their diagnosis and treatment. Imaging, including radiography, computed tomography (CT) and magnetic resonance imaging (MRI) is crucial for diagnosis, staging, treatment planning and follow-up. Surgical resection remains the mainstay of treatment for malignant primary vertebral tumours, but adjuvant radiotherapy and chemotherapy may be necessary for achieving complete tumour control depending on the type of tumour. In recent years, advances in imaging techniques and surgical approaches, such as en-bloc resection and spinal reconstruction, have improved the outcomes for patients with malignant primary vertebral tumours. However, the management can be complex due to the anatomy involved and the high morbidity and mortality associated with surgery. The different types of malignant primary vertebral lesions will be discussed in this article with an emphasis on the imaging features.

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.

Craniovertebral Junction Instability after Oncological Resection: A Narrative Review

The craniovertebral junction (CVJ) is a complex transition area between the skull and cervical spine. Pathologies such as chordoma, chondrosarcoma and aneurysmal bone cysts may be encountered in this anatomical area and may predispose individuals to joint instability. An adequate clinical and radiological assessment is mandatory to predict any postoperative instability and the need for fixation. There is no common consensus on the need for, timing and setting of craniovertebral fixation techniques after a craniovertebral oncological surgery. The aim of the present review is to summarize the anatomy, biomechanics and pathology of the craniovertebral junction and to describe the available surgical approaches to and considerations of joint instability after craniovertebral tumor resections. Although a one-size-fits-all approach cannot encompass the extremely challenging pathologies encountered in the CVJ area, including the possible mechanical instability that is a consequence of oncological resections, the optimal surgical strategy (anterior vs posterior vs posterolateral) tailored to the patient's needs can be assessed preoperatively in many instances. Preserving the intrinsic and extrinsic ligaments, principally the transverse ligament, and the bony structures, namely the C1 anterior arch and occipital condyle, ensures spinal stability in most of the cases. Conversely, in situations that require the removal of those structures, or in cases where they are disrupted by the tumor, a thorough clinical and radiological assessment is needed to timely detect any instability and to plan a surgical stabilization procedure. We hope that this review will help shed light on the current evidence and pave the way for future studies on this topic.

High-Throughput/High Content Imaging Screen Identifies Novel Small Molecule Inhibitors and Immunoproteasomes as Therapeutic Targets for Chordoma

Chordomas account for approximately 1-4% of all malignant bone tumors and 20% of primary tumors of the spinal column. It is a rare disease, with an incidence estimated to be approximately 1 per 1,000,000 people. The underlying causative mechanism of chordoma is unknown, which makes it challenging to treat. Chordomas have been linked to the T-box transcription factor T (TBXT) gene located on chromosome 6. The TBXT gene encodes a protein transcription factor TBXT, or brachyury homolog. Currently, there is no approved targeted therapy for chordoma. Here, we performed a small molecule screening to identify small chemical molecules and therapeutic targets for treating chordoma. We screened 3730 unique compounds and selected 50 potential hits. The top three hits were Ribociclib, Ingenol-3-angelate, and Duvelisib. Among the top 10 hits, we found a novel class of small molecules, including proteasomal inhibitors, as promising molecules that reduce the proliferation of human chordoma cells. Furthermore, we discovered that proteasomal subunits PSMB5 and PSMB8 are increased in human chordoma cell lines U-CH1 and U-CH2, confirming that the proteasome may serve as a molecular target whose specific inhibition may lead to better therapeutic strategies for chordoma.

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.

Chronic cerebrospinal fluid rhinorrhea as an initial presentation of chordoma: illustrative case

BACKGROUND

Skull base chordomas are typically extradural and present with cranial nerve deficits, headache, and visual disturbances. Clival chordoma involving the dura and presenting as a spontaneous cerebrospinal fluid (CSF) leak is extremely rare and can be mistaken for other skull base lesions. Here the authors present a case of chordoma with an unusual presentation.

OBSERVATIONS

A 43-year-old female who presented with clear nasal drainage was diagnosed with CSF rhinorrhea secondary to a clival defect previously thought to be ecchordosis physaliphora. The patient subsequently developed bacterial meningitis and underwent endoscopic, endonasal, transclival gross-total resection of the lesion with repair of the dural defect. Pathology revealed brachyury-positive chordoma. She received adjuvant proton beam radiotherapy and has remained stable for 2 years.

LESSONS

Spontaneous CSF rhinorrhea can occur as a rare primary presentation of clival chordoma, requiring careful radiological interpretation and a high index of suspicion for diagnosis. Chordoma cannot be reliably differentiated from benign notochordal lesions based on imaging alone; thus, intraoperative exploration and immunohistochemistry play key roles. Clival lesions presenting with CSF rhinorrhea should undergo prompt resection to facilitate diagnosis and prevent complications. Future studies on connections between chordoma and benign notochordal lesions may help to establish management guidelines.

Quality of Life in Chordoma Co-Survivors: Results from the Chordoma Foundation Survivorship Survey

INTRODUCTION

Chordomas are a rare form of aggressive bone cancer and are associated with poor quality of life (QOL). The present study sought to characterize demographic and clinical characteristics associated with QOL in chordoma co-survivors (caregivers of chordoma patients) and assess whether co-survivors are accessing care for QOL challenges.

METHODS

The Chordoma Foundation Survivorship Survey was electronically distributed to chordoma co-survivors. Survey questions assessed emotional/cognitive and social QOL, with significant QOL challenges being defined as experiencing >5 challenges within either of these domains. Fisher's exact test and the Mann-Whitney U test were used to analyze bivariate associations between patient/caretaker characteristics and QOL challenges.

RESULTS

Among the 229 respondents to our survey, nearly half (48.5%) reported a high number (>5) of emotional/cognitive QOL challenges. Co-survivors under 65 years of age were significantly more likely to experience a high number of emotional/cognitive QOL challenges (p<0.0001) while co-survivors greater than ten years past the end of treatment were significantly less likely to experience a high number of emotional/cognitive QOL (p=0.012). When asked about access to resources, a lack of knowledge of resources to address their emotional/cognitive and social QOL issues (34% and 35%, respectively) was the most common response.

CONCLUSION

Our findings suggest younger co-survivors are at high-risk for adverse emotional QOL outcomes. Additionally, over one-third of co-survivors did not know about resources to address their QOL issues. Our study may help guide organizational efforts to provide care and support to chordoma patients and their loved ones.

Evaluation of Long-Term Follow-Up in Ecchordosis Physaliphora versus Chordoma

OBJECTIVE

Ecchordosis physaliphora (EP) is a non-neoplastic notochord remnant with limited literature. We present a review on surgically-resected clival EP to evaluate if available follow-up is adequate to distinguish EP from chordomas.

METHODS

A systematic literature review was completed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Case reports or series of adults with histopathological and radiographic findings of surgically-resected EP were included. Articles including pediatric patients, systematic reviews, chordomas, and without microscopic or radiographic confirmation, or the surgical approach, were excluded. Corresponding authors were contacted twice to further evaluate outcomes.

RESULTS

Eighteen articles were included (n=25 patients; mean age 47.5 years +/- 12.6 (SD) months). All patients had symptomatic, surgically-resected EP, with CSF leak or rhinorrhea the most common symptom (48%). All but 3 had gross total resection, with endoscopic endonasal transsphenoidal transclival the most common approach (80%). All but 3 reported immunohistochemistry findings, with physaliphorous cells the most common. All but 5 patients had definitive follow-up (80%), with average of 19.5 +/- 17.2 (SD) months. One corresponding author reported longer-term follow-up for one patient (57 months). No recurrence or malignant transformation was reported. Mean time to clival chordoma recurrence (53.9 +/- 26.8 (SD) months) was also evaluated in a review of 8 studies.

CONCLUSIONS

Mean follow-up for resected EP was almost three times shorter than mean time to recurrence of chordomas. Available literature is likely inadequate to confirm the suspected benign nature of EP especially in reference to chordoma, precluding treatment and follow-up recommendations.

The role of Gamma Knife radiosurgery in the management of skull base chordoma

Objective

Chordoma is a slow-growing and locally aggressive cancer, which arises from the remnants of the primitive notochord. The first line treatment for the skull base chordoma is neurosurgery. Gamma Knife radiosurgery (GKS) is often be chosen especially in the setting of residual or recurrent chordomas. The purpose of this study is to evaluate the prognosis of patients with skull base chordoma who underwent GKS.

Methods

The present study was a retrospective analysis of 53 patients with skull base chordomas who underwent GKS. Univariate Cox and Kaplan-Meier survival analysis were performed to analyze the relationship between the tumor control time and the clinical characteristics.

Results

The 1-, 2-, 3-, and 5-year progression free survival (PFS) rates were 87, 71, 51, and 18%, respectively. After performing the univariate analysis, the clinical characteristics were not found to be significantly associated with the time of PFS; however, surgical history, peripheral dose, and tumor volume did have tendencies to predict the prognosis.

Conclusion

GKS provided a safe and relatively effective treatment for residual or recurrent chordomas after surgical resection. A higher tumor control rate depends on two approaches, an appropriate dose of radiation for the tumor and the accurate identification of the tumor margins.

Odds of Stage IV Bone Cancer Diagnosis Based on Socioeconomic and Geographical Factors: A National Cancer Database (NCDB) Review

BACKGROUND

There are significant differences in prognosis for osteosarcoma, Ewing sarcoma, chondrosarcoma, and chordomas based on the stage at diagnosis. The five-year survival of these bone cancers varies from 75-87% at an early stage of diagnosis and falls to 27-55% at a late stage of diagnosis.

PATIENTS AND METHODS

This study retrospectively evaluated the odds of stage I vs stage IV cancer at the time of diagnosis in patients with primary malignant bone tumors (osteosarcoma, chondrosarcoma, Ewing sarcoma and chordoma) diagnosed in the National Cancer Database (NCDB) between 2004 and 2018. Cross tabulations with Chi-square analysis were performed to evaluate frequencies of different socioeconomic and geographical characteristics between patients with stage I vs stage IV cancer. Multivariable binary logistic regression was performed to evaluate relationships between socioeconomic and geographical factors and the odds of stage IV cancer at the time of diagnosis. Statistical significance was set at α = 0.05.

RESULTS

8882 patients with stage I and 3063 with stage IV primary malignant bone tumors were identified. The odds of stage IV bone cancer at diagnosis are increased for patients on Medicaid (odds ratio [OR] = 1.298, 95% confidence interval [CI]: 1.043-1.616) or Medicare (OR = 1.795, 1.411-2.284). Odds of stage IV bone cancer at diagnosis were decreased with female sex (OR = 0.733, 0.671-0.800), private insurance (OR = 0.738, 0.601-0.905), and those treated at community cancer programs (OR = 0.542, 0.369-0.797), comprehensive cancer program (OR = 0.312, 0.215-0.452), or academic/research facilities (OR = 0.370, 0.249-0.550). No significant relationship was identified between the stage at diagnosis and race, ethnicity, Charlson-Deyo score, or education level. Stage IV cancer at diagnosis showed was proportionally lower in chondrosarcomas (17.1%) and chordomas (2.1%) than osteosarcomas (45.0%) and Ewing sarcomas (35.8%).

CONCLUSION

Odds of stage IV bone cancer at diagnosis are greater with male sex, Medicaid or Medicare insurance status, or treatment at community cancer programs. Providers should have a low suspicion for additional evaluation when treating patients with symptoms of bone cancer and should be aware of these disparities when treating people in these groups. This is to the authors' knowledge the first such study conducted through the NCDB.

A case report of lumbosacral plexopathy in a patient with a history of sacral chordoma and radiotherapy: Will the detection of myokymia on the EMG help to solve the case?1

BACKGROUND

When a patient with a prior history of malignancy and radiotherapy develops progressive weakness as a presentation of plexus involvement, the differential diagnosis usually rests between radiation-induced plexopathy and invasion from recurrent tumor. The presence of myokymic discharges is helpful in differentiating radiation-induced from neoplastic plexopathy.

OBJECTIVE

To present a case report of a patient with chordoma, a locally aggressive tumor, who was diagnosed with recurrent tumor accompanied by the occurrence of myokymia in needle electromyographic examination.

METHOD

A 55-year-old male patient with a history of chordoma and radiotherapy presented to our outpatient clinic with complaints of foot drop, and impaired walking for two months. His latest magnetic resonance imaging (MRI) which was performed three months earlier did not show recurrence. Upon electromyographic evaluation, myokymia, the pathognomic electromyography abnormal wave for radiation plexopathy was detected supporting a diagnosis of radiation plexitis rather than recurrent neoplastic invasion. One month later he presented with more severe pain and was re-evaluated by an MRI, on which a mass was detected indicating relapse.

CONCLUSION

With this case report, we would like to emphasize that the behaviour of the tumor should be considered and imaging should be repeated when tumors display aggressive or recurrent behaviour.

LOC554202 contributes to chordoma progression by sponging miR-377-3p and up-regulating SMAD3

Chordoma is a rare malignant bone tumor originating from the remnants of the notochord. Here, the role of long noncoding LOC554202 in chordoma progression and its associated mechanism were explored. Cell proliferation was analyzed by 3-(4, 5-dimethylthiazol-2-yl)-2, 5 diphenyltetrazolium bromide and colony formation assays. Flow cytometry was conducted to analyze cell apoptosis rate. The migration and invasion of chordoma cells were analyzed by transwell migration and invasion assays and wound healing assays. A xenograft tumor model was established in nude mice to explore the role of LOC554202 in regulating tumor growth in vivo . The interaction between microRNA-377-3p (miR-377-3p) and LOC554202 or sekelsky mothers against d PP (SMAD) family member 3 (SMAD3) was verified by dual-luciferase reporter and RNA immunoprecipitation assays. The glycolytic rate of chordoma cells was analyzed using glucose assay kit, lactic acid kit and ApoSENSOR ADP/ATP ratio assay kit. LOC554202 expression was upregulated in chordoma tissues and cell lines. LOC554202 silencing suppressed the proliferation, migration and invasion and induced the apoptosis of chordoma cells. LOC554202 knockdown restrained xenograft tumor growth in vivo . miR-377-3p was confirmed as a target of LOC554202, and miR-377-3p silencing largely overturned LOC554202 knockdown-mediated anti-tumor effects in chordoma cells. miR-377-3p interacted with the 3' untranslated region (3'UTR) of SMAD3 and miR-377-3p overexpression-mediated antitumor effects in chordoma cells were largely attenuated by SMAD3 overexpression. LOC554202 could positively regulate SMAD3 expression by sponging miR-377-3p in chordoma cells. LOC554202 contributed to the glycolysis of chordoma cells by targeting binding to miR-377-3p/SMAD3 axis. LOC554202 facilitated the proliferation, migration, invasion and glycolysis and inhibited the apoptosis of chordoma cells by mediating miR-377-3p/SMAD3 axis.