Chordoma: a systematic review of the epidemiology and clinical prognostic factors predicting progression-free and overall survival

Muscle metastasis from cervical chordoma: a case report

Chordomas are rare primary bone tumours that commonly occur in the sacrococcygeal and skull base region and have high rates of local recurrence. They have a locally aggressive course and the most common site of distant metastasis is the lung. The aim of this case report is to present the imaging findings of instance of muscle metastasis, a rare occurrence in cervical chordoma.

Long-term Outcomes following Proton-based Radiation Therapy for Pediatric Chordomas and Chondrosarcomas of the Mobile Spine and the Sacrum

PURPOSE

To report the first cohort of children with spinal and sacrococcygeal chordomas (CH) and chondrosarcomas (CHS) treated with proton-based radiotherapy (PRT).

MATERIALS/METHODS

Between 1989 and 2019, 52 pediatric patients ≤ 22 years old with spinal CH (n=43) or CHS (n=9) were treated with PRT at a single institution. The primary tumor originated in the C-spine (n=37, 71%), T-spine (n=6, 12%), L-spine (n=7, 14%), or sacrum (n=2, 3%). The CH group included 33 conventional and 10 atypical/poorly-differentiated chordomas. The CHS group included five conventional and four mesenchymal CHS. Pre-RT chemotherapy was administered to 13 (25%) patients. Salvage radiation was delivered to 13 (25%) patients with progressive disease. The median total dose was 74.5 Gy (RBE) [IQR, 69.8 - 76 Gy (RBE)] delivered in 1.8-2.5 Gy (RBE) daily fractions. Primary endpoints were overall survival (OS), disease-specific survival (DSS), and progression-free survival (PFS). A univariate and multivariable Cox regression analysis was performed to identify prognostic and predictive factors.

RESULTS

At a median follow-up of 11.4 years (IQR, 5.7 - 19.8) from the date of diagnosis, 17 (32.7%) patients recurred (8 local, 7 distant and 2 iatrogenic). Fifteen of these patients died of disease. The 5-, 10-, and 20-year OS were 82.7%, 72.3% and 72.3%, respectively. The 5-, 10-, and 20-year DSS were 86.1%, 77.5%, and 77.5%, respectively. The 5-, 10-,and 20-year PFS were 72.3%, 70.1% and 70.1%, respectively. The 20-year OS, DSS, and PFS for conventional CH were 93.9%, 97%, and 87.9%, respectively. Factors significantly associated with worse outcomes were poorly-differentiated chordoma subtype, pre-RT chemo, and low KPS (p<0.05). Pre-RT tumor progression was found to be a significant prognostic factor for PFS (p=0.02). Two patients developed late grade 3 toxicities.

CONCLUSIONS

This is the largest study of pediatric spinal and sacrococcygeal CH/CHS to date. High-dose PRT following surgical resection offers high disease control rates for conventional CH/CHS.

Characteristics and survival outcomes in pediatric patients with spinal chordomas: insights from the National Cancer Database and review of the literature

PURPOSE

Spinal chordomas are aggressive tumors that rarely occur in the pediatric population. Demographics and post-treatment outcomes in this select group of patients is poorly studied. We hence aimed to analyze the clinical characteristics, demographics, and survival outcomes of pediatric patients with spinal chordomas, in contrast to the adult population. To address this, the literature was reviewed to evaluate the coverage on spinal chordomas of the pediatric population, and the National Cancer Database (NCDB) was analyzed to provide insights into the US experience over the past two decades.

METHODS

A search of the literature was performed leveraging the MEDLINE and Web of Science electronic databases from inception until March 2024, using the keywords "spinal," "chordoma," and "pediatric". Additionally, the NCDB was queried for pediatric patients (≤ 21 years) with chordoma treated between 2004 and 2017. Baseline characteristics, tumor specifics, treatment details, and survival outcomes were collected and analyzed.

RESULTS

From the literature, 45 pediatric chordoma patients were identified, with a median age of 7 years. Most chordomas were in the cervical spine (40%), and 93% of the patients received surgical treatment. Gross total resection was achieved in 59% of cases, and 49% received adjuvant radiotherapy. Recurrence, metastasis, and mortality rates were 7%, 18%, and 24%, respectively at a median follow-up of 12 months. In the NCDB cohort, 53 pediatric patients (≤ 21 years) and 980 adults (> 21 years) were compared. Despite having smaller tumors in size, pediatric patients presented with more advanced tumors with a higher proportion of stage 4 tumors. They had more mobile spine chordomas (83% vs. 51%) and traveled further for treatment (57 vs. 27 miles). Pediatric patients also received higher radiation doses (5420 vs. 5049 cGy). Surgical resection and adjuvant radiotherapy were common treatments in both groups. After matching, outcomes, including survival rates and early mortality, were similar between age groups. Kaplan-Meier analysis showed no difference in overall survival probabilities between the age groups both prior to and after matching.

CONCLUSION

While pediatric patients with spinal chordomas present with more advanced stage tumors, they demonstrate similar overall survival outcomes when compared to adults. The current literature is mainly composed of single cases and other reports of low evidence levels.

Risk factors for metastatic disease at presentation with chordoma and its prognostic value

Background

Chordoma is a rare bone cancer arising from the embryonic notochord with special predilection to the axial skeleton. The locally destructive nature and metastatic potential of chordomas can lead to devastating outcomes in terms of survival. The purpose of this study was to examine potential risk factors predictive of metastatic disease at presentation and prognostic factors in patients with metastasis.

Methods

SEER was used to classify each patient as having metastatic or localized disease at the time of diagnosis. Patient-specific and tumor characteristics were analyzed to determine which factors were predictive of an increased rate of metastatic disease at presentation. These factors were analyzed using univariate as well as a multivariate logistic regression model. Prognostic factors for survival were analyzed using the Kaplan-Meier estimates with log-rank tests, and Cox proportional hazards models.

Results

We identified 1,241 cases of chordoma affecting the axial skeleton, and 117 (9.4%) of the patients presented with metastatic disease. The most common locations for metastasis at presentation were lung (6.0%), followed by bone (5.1%) and liver (3.4%). Based on the unadjusted logistic regression analysis, patients had the highest odds of metastatic disease at presentation if they had a tumor located in the sacrococcygeal area (OR = 1.72; 95% CI, 1.11-2.68; p = .015), a tumor with a dedifferentiated histological subtype (OR = 7.42; 95% CI, 2.31-23.79; p = .001) and a tumor size greater than 10 cm (OR = 4.57; 95% CI, 2.52-8.28; p = .009). Only the histological subtype remained significant when combined in a multivariate model controlling for age, sex, race, tumor location, histology, and size. For patients with recorded tumor size information (n = 858), the odds of metastasis at presentation increased by 12.2% with each additional centimeter of tumor size (OR = 1.122; 95% CI, 1.072-1.175; p < .0001). However, this lost significance in the multivariate model. Advanced age (hazard ratio, 2.06; 95% confidence interval, (1.18-3.60); p = .011) and dedifferentiated subtype (hazard ratio, 4.7; 95% confidence interval, (1.33-16.8); p = .02) were significant prognostic factors for survival in patients with metastatic chordoma.

Conclusions

Chordoma patients with dedifferentiated histological subtype were more likely to have metastatic disease at presentation. Advanced age and dedifferentiated histological subtype were independent predictors of increased mortality in patients with metastatic chordoma. Identification of this high-risk group may help providers in counseling their patients regarding the likelihood of discovering metastatic disease at the time of diagnosis of chordoma and predicting long term prognosis.

The skull base chordoma patient reported outcome survey (sbCPROS): a patient-centered, disease-specific tool for assessing quality of life in chordoma patients

PURPOSE

Chordomas are rare malignant tumors arising from the embryological notochord that present most frequently in the lumbosacral spine, followed by the skull base, with an overall 1/1,000,000 incidence. These tumors and their treatment significantly affect quality of life (QOL) due to intricate anatomical locations and aggressive treatment regimens. Despite these challenges, there are currently no disease-specific patient-reported outcome (PRO) surveys for chordomas. We aimed to develop a tool to assess QOL in patients with skull base chordomas (sbCs).

METHODS

Twenty-seven patients who underwent sbC resection were interviewed on QOL throughout their care. Grounded-theory analysis of interview transcripts generated 7 themes. We developed an initial survey with 79 items from existing general and anatomic-specific QOL assessment tools addressing these themes. Ten chordoma providers and 10 new patients completed an anonymous Qualtrics survey, rating items' relevance on a 5-point Likert scale to validate survey content. An a priori cutoff of > 3.0 was used for significant relevance. Mean relevance scores for each item were compared between providers and patients as well as between skull base respondents and 5 control patients with lumbar spine and sacral chordomas, using two-sided Mann-Whitney U-tests.

RESULTS

Seventy-four items reached the relevance threshold. These were consolidated to create the final 42-item Skull Base Chordoma Patient Reported Outcome Survey (sbCPROS). Providers significantly overvalued items related to the themes of pain (73%), sleep changes (60%), and sensory & motor symptoms (43%) relative to patients. Ten items were more relevant to skull base patients than patients with spinal tumors (p < 0.05).

CONCLUSION

The authors developed a novel patient-centered, disease-specific PRO instrument to assess change in QOL for sbC patients over time. sbCPROS may provide significant insight into the delivery of high quality care for patients with sbCs and guide patient-physician discussions about care decision-making.

Therapeutic strategies for mobile spine chordoma: en bloc Versus intralesional surgery with adjuvant charged-particle therapy

PURPOSE

The aim of this retrospective study is to analyze the impact of en bloc resection with negative margins versus intralesional resection plus adjuvant hadron-therapy (HT) on local control (LC) and overall survival (OS) in patients with mobile spine chordomas. Mechanical complications incidence as well as risk factors, and outcome differences are investigated as secondary endpoints.

METHODS

33 patients in a period from January 2013 to December 2021 were enrolled for the final analysis. The inclusion criteria were: lesions located in the mobile spine (C1-L5), age ≥ 15 years, minimum follow-up of 2 years, en bloc or intralesional surgical resection, virgin or recurrent chordomas, with only one previous surgical treatment.

RESULTS

No difference was found in terms of LC between the two groups. The presence of pathologic fracture at pre-operative imaging and the presence of macroscopic residual tumor after surgery, independently from its entity, seemed to be associated with an increased risk of LR. No difference was found between planned en bloc and planned intralesional surgery in terms of mechanical complications occurrence. Eight patients (24.24%) had mechanical complications during the follow up period: male sex, presence of pathologic fracture at baseline, a combined surgical approach, the use of carbon fiber-only hardware appeared to be associated with an increased risk of mechanical complications after the primary surgery.

CONCLUSIONS

En bloc resection, whenever possible, is always to be preferred for its widely recognized potential in LC and OS improvement. However, technology advances in high-dose conformal charged-particle therapy have allowed improvement of local control rates as an adjuvant therapy of intralesional surgery for mobile spine chordoma, with acceptable acute and chronic toxicity.

Chordoma Spontaneous Regression After COVID-19

Chordomas are a low-to-intermediate-grade slow-growing subtype of sarcoma, but show propensity to grow and invade locally with recurrence and metastasis in 10-40% of cases. We describe the first case of spontaneous regression of a solid tumor (histologically and immunohistochemically proven chordoma) after COVID-19. A female patient with clival chordoma underwent occipitocervical fixation prior to tumor resection. In the early post-operative stage following the arthrodesis procedure, she was diagnosed with COVID-19. Six months after COVID-19, she finally came back for endoscopic endonasal resection of the tumor and pre-operative MRI surprisingly showed 98.9% regression of the tumor volume. Tumor resection was performed, and both histopathological and immunohistochemistry confirmed diagnosis of chordoma with positive brachyury levels. She showed improvement of right hemiparesis and left-sided tongue palsy. The tumor was comprised of tumor-infiltrating inflammatory cells. CD3 and CD68 were positive, suggesting the presence of T-lymphocytes and macrophages. CD20 and CD56 were negative, suggesting the absence of B-lymphocytes and NK-cells. The authors believe that the onset of COVID-19 exacerbated the patient's immune response and improved anti-tumor immunity. It was concluded that T-cells, which are involved in the COVID-19 immune response and were found infiltrating the tumor, acted as a critical pathway to this event. Further studies are encouraged in order to gain a better understanding of the SARS-CoV-2-chordoma interaction.

Chordoma cells possess bone-dissolving activity at the bone invasion front

PURPOSE

Chordomas are malignant tumors that destroy bones, compress surrounding nerve tissues and exhibit phenotypes that recapitulate notochordal differentiation in the axial skeleton. Chordomas recur frequently, as they resist radio-chemotherapy and are difficult to completely resect, leading to repeated bone destruction and local expansion via unknown mechanisms. Here, using chordoma specimens and JHC7 chordoma cells, we asked whether chordoma cells possess bone-dissolving activity.

METHODS

CT imaging and histological analysis were performed to evaluate the structure and mineral density of chordoma-invaded bone and osteolytic marker expression. JHC7 cells were subjected to immunocytochemistry, imaging of cell fusion, calcium dynamics and acidic vacuoles, and bone lysis assays.

RESULTS

In patients, we found that the skull base invaded by chordoma was highly porous, showed low mineral density and contained brachyury-positive chordoma cells and conventional osteoclasts both expressing the osteolytic markers tartrate-resistant acid phosphatase (TRAP) and collagenases. JHC7 cells expressed TRAP and cathepsin K, became multinucleated via cell-cell fusion, showed spontaneous calcium oscillation, and were partly responsive to the osteoclastogenic cytokine RANKL. JHC7 cells exhibited large acidic vacuoles, and nonregulatory bone degradation without forming actin rings. Finally, bone-derived factors, calcium ions, TGF-β1, and IGF-1 enhanced JHC7 cell proliferation.

CONCLUSION

In chordoma, we propose that in addition to conventional bone resorption by osteoclasts, chordoma cells possess bone-dissolving activity at the tumor-bone boundary. Furthermore, bone destruction and tumor expansion may occur in a positive feedback loop.

Prognostic factors and overall survival in pelvic Ewing's sarcoma and chordoma: A comparative SEER database analysis

Background

This study aimed to develop and validate nomograms to predict overall survival (OS) for pelvic Ewing's sarcoma (EWS) and chordoma, identify prognostic factors, and compare outcomes between the two conditions.

Methods

We identified patients diagnosed with pelvic EWS or chordoma from the SEER database (2001-2019). Independent risk factors were identified using univariate and multivariate Cox regression analyses, and these factors were used to construct nomograms predicting 3-, 5-, and 10-year OS. Validation methods included AUC, calibration plots, C-index, and decision curve analysis (DCA). Kaplan-Meier curves and log-rank tests compared survival differences between low- and high-risk groups.

Results

The study included 1175 patients (EWS: 611, chordoma: 564). Both groups were randomly divided into training (70 %) and validation (30 %) cohorts. OS was significantly higher for chordoma. Multivariate analysis showed year of diagnosis, income, stage, and surgery were significant for EWS survival, while age, time to treatment, stage, and surgery were significant for chordoma survival. Validation showed the nomograms had strong predictive performance and clinical utility.

Conclusions

The nomograms reliably predict overall survival (OS) in pelvic EWS and chordoma, helping to identify high-risk patients early and guide preventive measures. The study also found that survival rates are significantly higher for chordoma, highlighting different prognostic profiles between EWS and chordoma.

The impact of socioeconomic determinants on the access to care and survival in patients with spinal chordomas- a national cancer database analysis

PURPOSE

Chordomas are rare malignant neoplasms primarily treated surgically. Disparities related to race and socioeconomic status, may affect patient outcomes. This study aims to identify prognostic factors for access to care and survival in patients with spinal chordomas.

METHODS

The NCDB database was queried between the years 2004 and 2017. Kaplan-Meier curves were constructed to compare survival probabilities among different groups, based on race and socioeconomic determinents.

RESULTS

1769 patients were identified, with 87% being White, 5% Hispanic, 4% Black, and Asian each. The mean age was 61.3 years. Most patients received care at academic/research centers and lived in a large metropolitan area, with no difference between races. A significantly higher percentage of Black patients did not undergo surgery (p < 0.001), with no statistically significant difference in survival between races (p = 0.97). A higher survival probability was seen in patients with other government insurances (p < 0.0001), in higher income quartiles (p < 0.0001), in metropolitan areas (p = 0.023), and at an academic/research center (p < 0.0001). A lower survival probability was seen in patients who are uninsured, in rural areas, and at community cancer programs (p < 0.0001).

CONCLUSION

This study highlights disparities in access to surgical intervention for patients with spinal chordomas, especially among Black individuals. It emphasizes the significant impact of insurance status and income on access to surgical care and highlights geographical and institutional variations in survival rates. Addressing socioeconomic differences is crucial for fostering equity in neurosurgical outcomes.

Intraparenchymal Chordoma in the Brain Stem: A Review of Surgical Management and Case Highlight

We present a rare case of an intraparenchymal chordoma in the brain stem of a 69-year-old male with a history of multiple chordoma recurrences. Chordomas are uncommon tumors that originate from notochordal remnants, with intraparenchymal presentations in the brain stem being particularly rare. A 69-year-old male with a history of clival chordoma three years after primary endoscopic resection and adjuvant proton-beam radiotherapy and a recurrence one year postoperatively for which he underwent a second surgery, presented with severe headaches, weakness, diaphoresis, and difficulty ambulating. Head CT in the ER revealed a 2.7 x 3.5 cm hyperdense lesion in the pons, indicating acute hemorrhage. Magnetic resonance imaging (MRI) suggested a hemorrhagic radiation-induced cavernoma. A right retrosigmoid craniotomy was performed, and the lesion was resected without major complications. Final pathology reported an intraparenchymal hemorrhagic chordoma. To our knowledge, this is the first case of intra-axial chordoma, particularly in the brain stem. It highlights the importance of considering intraparenchymal chordoma on the differential when evaluating for recurrence versus other treatment-induced pathologies and changes. This may prompt the neurosurgeon to reconsider treatment options and weigh the risks of watchful waiting versus biopsy or even aggressive surgical management.

Systematic Review and Meta-Analysis of Particle Beam Therapy versus Photon Radiotherapy for Skull Base Chordoma: TRP-Chordoma 2024

[Objective] The aim of this study was to compare the efficacy of particle beam therapy (PT) with photon radiotherapy (RT) for treatment of skull base chordoma. [Methods] A systematic review was conducted for skull base chordoma treated with PT or photon RT reported from 1990 to 2022. Data were extracted for overall survival (OS) and progression-free survival (PFS), late adverse events, age, gender, gross total resection (GTR) rates, tumor volume, total irradiation dose, and treatment modality. Random-effects meta-regression analysis with the treatment modality as an explanatory variable was performed for each outcome to compare the modalities. [Results] A meta-analysis of 30 selected articles found 3- and 5-year OS rates for PT vs. photon RT or combined photon RT/proton beam therapy (PBT) of 90.8% (95% CI: 87.4-93.3%) vs. 89.5% (95% CI: 83.0-93.6%), p = 0.6543; 80.0% (95% CI: 75.7-83.6%) vs. 89.5% (95% CI: 83.0-93.6%), p = 0.6787. The 5-year PFS rates for PT vs. photon RT or photon RT/PBT were 67.8% (95% CI: 56.5-76.7%) vs. 40.2% (95% CI: 31.6-48.7%), p = 0.0004. A random-effects model revealed that the treatment modality (PT vs. photon RT or photon RT/PBT) was not a significant factor for 3-year OS (p = 0.42) and 5-year OS (p = 0.11), but was a significant factor for 5-year PFS (p < 0.0001). The rates of brain necrosis were 8-50% after PT and 0-4% after photon RT or photon RT/PBT. [Conclusion] This study shows that PT results in higher PFS compared to photon RT for skull base chordoma, but that there is a tendency for a higher incidence of brain necrosis with PT. Publication and analysis of further studies is needed to validate these findings.

Chordoma arising from the coccygeal disc and mimicking a pilonidal cyst

Chordomas are rare, low-grade malignant tumors often found in the sacrococcygeal region and prone to local recurrence. We report an atypical presentation of a 40-year-old patient with a symptomatic midline retrococcygeal lesion that was presumptively treated as a pilonidal cyst due to its clinical and imaging features. After surgical pathology rendered the diagnosis of chordoma, the patient required salvage surgery in the form of partial sacrectomy with soft tissue flap coverage. In addition to the unusually predominant retrococcygeal location, surgical pathology identified an intervertebral disc origin rather than the typical osseous origin. To our knowledge, this presentation of chordoma with coccygeal intervertebral origin and a large subcutaneous mass at imaging has rarely been reported in the literature. We describe this case to raise awareness of atypical presentations of sacrococcygeal chordoma that may lead to erroneous presumptive diagnosis and treatment.

Impact of CDK Inhibitors on TBXT Expression in Chordoma Cell Lines Including the First Stable Cell Line of a High-Grade Chordoma

Chordomas are very rare malignant neoplasms of the bone occurring almost exclusively along the spine. As the tumours are thought to arise from notochordal remnants, the vast majority of chordomas express the TBXT gene, resulting in detectable nuclear amounts of its gene product brachyury. This T-Box transcription factor is commonly recognised as being essential in chordoma cells, and limiting TBXT expression is thought to be the key factor in controlling this tumour. Although the tumour is rare, distinct molecular differences and vulnerabilities have been described with regard to its location and the progression status of the disease, rendering it mandatory for novel cell lines to reflect all relevant chordoma subtypes. Here, we describe a novel chordoma cell line arising from the pleural effusion of a disseminated, poorly differentiated chordoma. This cell line, U-CH22, represents a highly aggressive terminal chordoma and, therefore, fills a relevant gap within the panel of available cell culture models for this orphan disease. CDK7 and CDK9 inhibition was lately identified as being effective in reducing viability in four chordoma cell lines, most likely due to a reduction in brachyury levels. In this study, we determined the capability of the CDK7 inhibitor THZ1 and the CDK1/2/5/9 inhibitor dinaciclib to reduce TBXT expression at mRNA and protein levels in a broad range of nine cell lines that are models of primary, recurrent, and metastasised chordoma of the clivus and the sacrum.

Prognostic nomogram in middle-aged and elderly patients with chordoma: A SEER-based study

BACKGROUND

Chordoma is a bone tumor that tends to occur in middle-aged and elderly people. It grows relatively slowly but is aggressive. The prognosis of middle-aged and elderly patients with chordoma is quite different from that of young patients with chordoma.

OBJECTIVES

The purpose of the research was to construct a nomogram to predict the Individualized prognosis of middle-aged and elderly (age greater than or equal to 40 years) patients with chordoma.

METHODS

In this study, we screened 658 patients diagnosed with chordoma from 1983 to 2015 in the Surveillance, Epidemiology, and End Results (SEER) database. We determined the independently prognostic factors that affect the survival of patients by univariate and multivariate Cox proportional hazards model. Based on the independent prognostic factors, we constructed a nomogram to predict the overall survival (OS) rates of middle-aged and elderly patients with chordoma at 3 and 5 years. The validation of this nomogram was completed by evaluating the calibration curve and the C-index.

RESULTS

We screened a total of 658 patients and divided them into two cohort. Training cohort had 462 samples and validation cohort had 196 samples. The multivariate Cox proportional hazards model of the training group showed an association of age, tumor size, histology, primary site, surgery, and extent of disease with OS rates. Based on these results, we constructed the corresponding nomogram. The calibration curve and C-index showed the satisfactory ability of the nomogram in terms of predictive ability.

CONCLUSION

Nomogram can be an effective prognostic tool to assess the prognosis of middle-aged and elderly patients with chordoma and can help clinicians in medical decision-making and enable patients to receive more accurate and reasonable treatment.

Incidence and centralization of chordoma in the Netherlands: A nationwide study between 1991 and 2020

INTRODUCTION

Chordomas are rare malignant bone tumors arising in the axial skeleton, with an incidence of 0.3-0.88 per million inhabitants. We studied the annual incidence rate and centralization of treatment for chordoma in the Netherlands.

METHODS

We retrieved pathology excerpts from the PALGA nationwide Dutch Pathology Registry between 1991 and 2019 for patients with a chordoma to calculate incidence rates. From pathology reports we extracted patient age at diagnosis, sex, year of diagnosis, localization of primary tumor, histologic chordoma subtype (conventional including chondroid, poorly differentiated or dedifferentiated), center of diagnosis (bone tumor referral center (BTC) or other hospital), and partial identification of the BTCs.

RESULTS

A total of 420 individual chordoma patients were identified in the given time period. The incidence of chordoma increased from 0.593 per million inhabitants between 1991-1995 to 1.111 from 2015-2019 (P = 0.001). Median age at diagnosis was 63 years (range 1-95), 252 patients (60%) were male. The proportion of samples analyzed in a BTC either primarily or secondary, as a consultation, revision or referral, increased significantly from 29.3% to 84.4% (P < 0.001). Most primary and secondary samples were analyzed at the Leiden University Medical Center (LUMC, 54.4% and 57% respectively).

CONCLUSIONS

This study shows an increase in the standardized incidence of pathology proven chordoma in the Netherlands. We observed an increase in samples being analysed in the specialized BTCs as well, which is in line with current guidelines and will hopefully lead to more accurate diagnoses and optimal treatment plans for chordoma patients in specialized treatment centers.

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.

Clivus-Cervical Stabilization through Transoral Approach in Patients with Craniocervical Tumor: Three Cases and Surgical Technical Note

Craniocervical tumors lead to cervical pain, instability, and neurological symptoms, reducing the quality of life. Effective surgical intervention at the craniocervical junction (CCJ) is critical and complex, involving comprehensive approaches and advanced reconstructive techniques. This study, conducted at Mexico City's National Institute of Cancerology, focused on three surgical cases that occurred in 2023 involving tumors at the CCJ: two chordomas and one prostate adenocarcinoma. We utilized a specialized technique: clivus-cervical stabilization reinforced with a polymethylmethacrylate (PMMA)-filled cervical mesh. Postoperatively, patients showed marked neurological recovery and reduced cervical pain, with enhanced Karnofsky and Eastern Cooperative Oncology Group (ECOG) scores indicating improved life quality. The surgical technique provided excellent exposure and effective tumor resection, utilizing PMMA-filled cervical mesh for stability. Tumoral lesions at the CCJ causing instability can be surgically treated through a transoral approach. This type of approach should be performed with precise indications to avoid complications associated with the procedure.

Notochordal cells: A potential therapeutic option for intervertebral disc degeneration

Intervertebral disc degeneration (IDD) is a prevalent musculoskeletal degenerative disorder worldwide, and ~40% of chronic low back pain cases are associated with IDD. Although the pathogenesis of IDD remains unclear, the reduction in nucleus pulposus cells (NPCs) and degradation of the extracellular matrix (ECM) are critical factors contributing to IDD. Notochordal cells (NCs), derived from the notochord, which rapidly degrades after birth and is eventually replaced by NPCs, play a crucial role in maintaining ECM homeostasis and preventing NPCs apoptosis. Current treatments for IDD only provide symptomatic relief, while lacking the ability to inhibit or reverse its progression. However, NCs and their secretions possess anti-inflammatory properties and promote NPCs proliferation, leading to ECM formation. Therefore, in recent years, NCs therapy targeting the underlying cause of IDD has emerged as a novel treatment strategy. This article provides a comprehensive review of the latest research progress on NCs for IDD, covering their biological characteristics, specific markers, possible mechanisms involved in IDD and therapeutic effects. It also highlights significant future directions in this field to facilitate further exploration of the pathogenesis of IDD and the development of new therapies based on NCs strategies.

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.

Skull Base Tumors

OBJECTIVE

This article reviews the presenting features, molecular characteristics, diagnosis, and management of selected skull base tumors, including meningiomas, vestibular schwannomas, pituitary neuroendocrine tumors, craniopharyngiomas, chordomas, ecchordosis physaliphora, chondrosarcomas, esthesioneuroblastomas, and paragangliomas.

LATEST DEVELOPMENTS

Skull base tumors pose a management challenge given their complex location and, as a result, the tumors and treatment can result in significant morbidity. In most cases, surgery, radiation therapy, or both yield high rates of disease control, but the use of these therapies may be limited by the surgical accessibility of these tumors and their proximity to critical structures. The World Health Organization classification of pituitary neuroendocrine tumors was updated in 2022. Scientific advances have led to an enhanced understanding of the genetic drivers of many types of skull base tumors and have revealed several potentially targetable genetic alterations. This information is being leveraged in the design of ongoing clinical trials, with the hope of rendering these challenging tumors treatable through less invasive and morbid measures.

ESSENTIAL POINTS

Tumors involving the skull base are heterogeneous and may arise from bony structures, cranial nerves, the meninges, the sinonasal tract, the pituitary gland, or embryonic tissues. Treatment often requires a multidisciplinary approach, with participation from radiation oncologists, medical oncologists, neuro-oncologists, and surgical specialists, including neurosurgeons, otolaryngologists, and head and neck surgeons. Treatment has largely centered around surgical resection, when feasible, and the use of first-line or salvage radiation therapy, with chemotherapy, targeted therapy, or both considered in selected settings. Our growing understanding of the molecular drivers of these diseases may facilitate future expansion of pharmacologic options to treat skull base tumors.

Five-Fraction Proton Therapy for the Treatment of Skull Base Chordomas and Chondrosarcomas: Early Results of a Prospective Series and Description of a Clinical Trial

(1) Background: Our purpose is to describe the design of a phase II clinical trial on 5-fraction proton therapy for chordomas and chondrosarcomas of the skull base and to present early results in terms of local control and clinical tolerance of the first prospective series. (2) Methods: A dose of 37.5 GyRBE in five fractions was proposed for chordomas and 35 GyRBE in five fractions for chondrosarcomas. The established inclusion criteria are age ≥ 18 years, Karnofsky Performance Status ≥ 70%, clinical target volume up to 50 cc, and compliance with dose restrictions to the critical organs. Pencil beam scanning was used for treatment planning, employing four to six beams. (3) Results: A total of 11 patients (6 chordomas and 5 chondrosarcomas) were included. The median follow-up was 12 months (9-15 months) with 100% local control. Acute grade I-II headache (64%), grade I asthenia and alopecia (45%), grade I nausea (27%), and grade I dysphagia (18%) were described. Late toxicity was present in two patients with grade 3 temporal lobe necrosis. (4) Conclusions: Hypofractionated proton therapy is showing encouraging preliminary results. However, to fully assess the efficacy of this therapeutic approach, future trials with adequate sample sizes and extended follow-ups are necessary.

Sacrectomy with Posterior-Only Approach in Sacral Tumors: An Analysis of 26 Cases and Review of Literature

BACKGROUND

Sacral masses can be removed using anterior, posterior, or combined approaches. Achieving total sacrectomy through a posterior-only approach results in a shorter procedure time, minimal tissue damage, and a reduced risk of complications. In this study, we aimed to share our experience with performing total sacrectomy using a posterior-only approach in 26 patients and to assess their clinical outcomes at our center.

MATERIALS AND METHODS

This retrospective study examines the clinical progression, surgical response, and outcomes of 26 patients with various sacral mass pathologies. We accessed patient information from our hospital records.

RESULTS

The study included 14 men (54%) and 12 women (46%), with an average age of 49.8 years. Most cases had a normal body mass index, while 6 were overweight. Sacrectomy was performed at a high level in 12 patients and at a middle level in 14 patients. In addition to pain, motor deficits were observed in 9 patients, and sphincter dysfunction was found in 5. Preoperative embolization was conducted for 11 patients. The most prevalent lesions were chordoma (8 patients), malignant peripheral nerve sheath tumor (4 patients), giant cell tumor (3 patients), and solitary plasmacytoma (3 patients). Only 1 patient experienced a temporary partial motor deficit after surgery. There were no instances of cerebrospinal fluid leakage. Five patients experienced local recurrence, and 1 had distant metastasis.

CONCLUSIONS

Performing sacrectomy for large or giant sacral tumors through a posterior approach is both feasible and safe, resulting in reduced morbidity and no significant change in overall survival.

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.

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.

Clinicopathological Predictors of Survival for Parotid Mucoepidermoid Carcinoma: A Systematic Review

OBJECTIVE

Various prognostic factors are associated with the survival of patients with parotid mucoepidermoid carcinoma (MEC). The aim of this systematic review is to summarize the clinical and pathologic prognostic factors on survival outcomes in patients with parotid MEC.

DATA SOURCES

Articles published from database inception to July 2020 on OVID Medline, OVID Embase, Cochrane Central, and Scopus.

REVIEW METHODS

Studies were included that reported clinical or pathologic prognostic factors on survival outcomes for adult patients with parotid MEC. Data extraction, risk of bias, and quality assessment were conducted by 2 independent reviewers.

RESULTS

A total of 4290 titles were reviewed, 396 retrieved for full-text screening, and 18 included in the review. The average risk of bias was high, and quality assessment for the prognostic factors ranged from very low to moderate. Prognostic factors that were consistently associated with negative survival outcomes on multivariate analysis included histologic grade (hazard ratio [HR], 5.66), nodal status (HR, 2.86), distant metastasis (HR, 3.10-5.80), intraparotid metastasis (HR, 13.52), and age (HR, 1.02-6.86). Prognostic factors that inconsistently reported associations with survival outcomes were TNM stage, T classification, and N classification.

CONCLUSION

Histologic grade, nodal status, distant metastasis, intraparotid metastasis, and age were associated with worse survival outcomes. These prognostic factors should be considered when determining the most appropriate treatment and follow-up plan for patients with parotid MEC.

SMARCB1 Loss in Poorly Differentiated Chordomas Drives Tumor Progression

Poorly differentiated (PD) chordoma, a rare, aggressive tumor originating from notochordal tissue, shows loss of SMARCB1 expression, a core component of the Switch/Sucrose Non-Fermentable (SWI/SNF) chromatin remodeling complexes. To determine the impact of SMARCB1 re-expression on cell growth and gene expression, two SMARCB1-negative PD chordoma cell lines with an inducible SMARCB1 expression system were generated. After 72 hours of induction of SMARCB1, both SMARCB1-negative PD chordoma cell lines continued to proliferate. This result contrasted with those observed with SMARCB1-negative rhabdoid cell lines in which SMARCB1 re-expression caused the rapid inhibition of growth. We found that the lack of growth inhibition may arise from the loss of CDKN2A (p16INK4A) expression in PD chordoma cell lines. RNA-sequencing of cell lines after SMARCB1 re-expression showed a down-regulation for rRNA and RNA processing as well as metabolic processing and increased expression of genes involved in cell adhesion, cell migration, and development. Taken together, these data establish that SMARCB1 re-expression in PD chordomas alters the repertoire of SWI/SNF complexes, perhaps restoring those associated with cellular differentiation. These novel findings support a model in which SMARCB1 inactivation blocks the conversion of growth-promoting SWI/SNF complexes to differentiation-inducing ones, and they implicate SMARCB1 loss as a late event in tumorigenic progression. Importantly, the absence of growth inhibition after SMARCB1 restoration creates a unique opportunity to identify therapeutic vulnerabilities.

Radiotherapy After Gross Total Resection of Skull Base Chordoma: A Surveillance, Epidemiology, and End Results Database Analysis of Survival Outcomes

OBJECTIVE

Skull base chordoma is a rare and locally destructive malignancy which presents unique therapeutic challenges. While achieving gross total resection (GTR) confers the greatest survival advantage, the role of adjuvant radiotherapy (RT) for patients who receive GTR remains unclear in the absence of prospective trials. Here, we aim to assess the effect of RT on survival outcomes in skull base chordoma patients who receive GTR by utilizing the Surveillance, Epidemiology, and End Results (SEER) database.

METHODS

Patients with diagnostic, primary site, and resection codes specific for chordoma, skull base, and GTR, respectively, were queried in the SEER database (2000-2018). Kaplan-Meier curves (log-rank test) were constructed and Cox proportional hazards models were used to assess survival outcomes.

RESULTS

A total of 115 skull base chordomas undergoing GTR were identified, of which 37 (32%) received no RT and 78 (68%) received RT. Median follow-up was 55.00 months (range: 0.00-227.00). Overall survival (OS) of patients with GTR was 85% and 70% at 5 and 10 years, respectively. Multivariate Cox proportional hazard analysis among chordoma patients undergoing GTR found age ≥65 (P < 0.01) was associated with poorer OS outcomes. RT appeared to trend toward offering benefit in terms of OS in patients after GTR, however this did not achieve statistical significance in the adjusted model (HR = 0.51, CI = 0.23-1.16, P = 0.09). When comparing, disease-specific survival was also not improved in patients undergoing RT (HR = 0.58, CI = 0.23-1.46, P = 0.25).

CONCLUSIONS

It remains unclear whether RT after GTR of chordoma improved survival outcomes among SEER database patients.

Proton or Carbon Ion Therapy for Skull Base Chordoma: Rationale and First Analysis of a Mono-Institutional Experience

Background: Skull base chordomas are radio-resistant tumors that require high-dose, high-precision radiotherapy, as can be delivered by particle therapy (protons and carbon ions). We performed a first clinical outcome analysis of particle therapy based on the initial 4-years of operation. Methods: Between August 2017 and October 2021, 44 patients were treated with proton (89%) or carbon ion therapy (11%). Prior gross total resection had been performed in 21% of lesions, subtotal resection in 57%, biopsy in 12% and decompression in 10%. The average prescription dose was 75.2 Gy RBE in 37 fractions for protons and 66 Gy RBE in 22 fractions for carbon ions. Results: At a median follow-up of 34.3 months (range: 1–55), 2-, and 3-year actuarial local control rates were 95.5% and 90.9%, respectively. The 2-, and 3-year overall and progression-free survival rates were 97.7%, 93.2%, 95.5% and 90.9%, respectively. The tumor volume at the time of particle therapy was highly predictive of local failure (p < 0.01), and currently, there is 100% local control in patients with tumors < 49 cc. No grade ≥3 toxicities were observed. There was no significant difference in outcome or side effect profile seen for proton versus carbon ion therapy. Five patients (11.4%) experienced transient grade ≤2 radiation-induced brain changes. Conclusions: The first analysis suggests the safety and efficacy of proton and carbon ion therapy at our center. The excellent control of small to mid-size chordomas underlines the effectiveness of particle therapy and importance of upfront maximum debulking of large lesions.

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.

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

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

Case Report of AdAPT-001-Mediated Sensitization to a Previously Failed Checkpoint Inhibitor in a Metastatic Chordoma Patient

Chordoma is a rare, but aggressive bone tumor with a high recurrence rate that primarily arises at the cranial and caudal ends of the axial skeleton. Systemic chemotherapies are not effective against the tumor, and outside of surgical resection and radiation, no approved options are available. Prognosis depends on the extent of surgical resection, with the more the better, and adjuvant radiotherapy. Herein is presented the first-ever case of a recurrent chordoma patient that responded to the combination of one dose of an experimental TGF-beta trap carrying oncolytic adenovirus, known as AdAPT-001, followed by immune checkpoint inhibitor therapy, despite prior progression on an anti-PD-1. This case report highlights the potential of AdAPT-001 as a treatment modality in combination with checkpoint inhibition for recurrent chordoma.

Treatment Response of Sacrococcygeal Chordoma to Palliative Stereotactic Body Radiotherapy: A Case Report

Chordomas are rare and locally aggressive tumours that arise from embryonic remnants of the notochord, with a predilection for the skull base, mobile spine, and sacrum. Sacral or sacrococcygeal chordomas can be particularly difficult to manage because of their large size at presentation and involvement of adjacent organs and neural structures. Although the recommended definitive therapy for such tumours is either en bloc resection with or without adjuvant radiotherapy (RT) or definitive fractionated RT with charged particle therapy, older and/or less-fit patients may not necessarily be accepting of said approaches due to the potential morbidities and challenging logistic requirements. Here, we report a case of a 79-year-old male presenting with intractable lower limb pain and neurologic deficits due to a large de novo sacrococcygeal chordoma. The patient was successfully treated with a 5-fraction course of stereotactic body radiotherapy (SBRT), given with palliative intent, with complete relief of his symptoms achieved approximately 21 months after RT and without the development of any iatrogenic toxicities. In view of this case, ultra-hypofractionated SBRT may be a suitable option for the palliation of large de novo sacrococcygeal chordomas for selected patients to reduce their symptom burden and improve their quality of life.

Skull Base Registries: A Roadmap

Hospitals, payors, and patients increasingly expect us to report our outcomes in more detail and to justify our treatment decisions and costs. Although there are many stakeholders in surgical outcomes, physicians must take the lead role in defining how outcomes are assessed. Skull base lesions interact with surrounding anatomy to produce a complex spectrum of presentations and surgical challenges, requiring a wide variety of surgical approaches. Moreover, many skull base lesions are relatively rare. These factors and others often preclude the use of prospective randomized clinical trials, thus necessitating alternate methods of scientific inquiry. In this paper, we propose a roadmap for implementing a skull base registry, along with expected benefits and challenges.

Management of Chordoma of the Sacrum and Mobile Spine

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Chordomas account for 1% to 4% of primary tumors of the spine and sacrum.

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En bloc resection is the preferred surgical treatment for the management of chordomas.

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Proton beam radiation is increasingly being used as a postoperative radiation modality for the treatment of chordomas.

Poorly Differentiated Chordoma of the Clivus With Loss of SMARCB1 Expression in a Pediatric Patient: A Case Report

Poorly differentiated chordoma (PDC) is a rare, aggressive subtype of chordoma. A two-year-old girl presented with cervical pain, limb paralysis and respiratory failure. Magnetic resonance imaging and positron emission tomography-computed tomography revealed a tumor compressing the pons at the clivus and osteoblastic metastatic lesions of the left upper arm and right iliac bone. Her tumors shrank substantially after treatment with chemotherapy and proton beam therapy. Our initial diagnosis was an atypical teratoma/rhabdoid tumor, but final diagnosis of PDC was made on the basis of the immunohistochemical expression of brachyury. In addition, the detection of SMARCB1/INI1 mutation confirmed the diagnosis of PDC.

Adjuvant stereotactic radiosurgery with or without postoperative fractionated radiation therapy in adults with skull base chordomas: a systematic review

OBJECTIVE

The objective of this retrospective study was to compare the survival of patients with biopsy-proven skull base chordoma who had undergone stereotactic radiosurgery (SRS) with versus without prior fractionated radiation therapy (RT).

METHODS

Relevant articles from database inception to September 2021 were retrieved from the PubMed, Scopus, Web of Science, and Cochrane databases for a systematic review of treatment protocols. Studies were included if they 1) involved adult patients (age ≥ 18 years) with histologically and radiologically confirmed chordomas located within the clival skull base region and treated with SRS; 2) reported data on clinical features, SRS protocols, and outcomes; and 3) were written in the English language. Studies were excluded if they 1) were literature reviews, case reports, technical notes, abstracts, or autopsy reports; 2) did not clearly differentiate the data of patients with chordomas from the data of patients with different tumors or the data of patients with chordomas in locations other than the skull base; or 3) lacked histological confirmation or treatment and outcome data. Extracted data included the following: study author and publication year, patient age and sex, symptoms, cranial nerve involvement, invaded structures, lesion size, treatment modality, surgical details, histopathological type, RT modality, SRS parameters, complications, postradiosurgery outcomes, complications, and survival outcomes.

RESULTS

After the selection process, 15 articles describing 130 patients met the study eligibility criteria, including 94 patients who had undergone postresection SRS (NoRT group) and 36 who had undergone postresection fractionated RT and subsequent SRS (RT group). The NoRT and RT groups were comparable in age (51.3 vs 47.4 years, respectively), sex (57.1% vs 58.3% male), tumor volume (9.5 vs 11.2 cm3), SRS treatment parameters (maximum dose: 35.4 vs 42.2 Gy, marginal dose: 19.6 vs 20.6 Gy, treatment isodose line: 60.2% vs 65.2%), and SRS adverse effects (10.9% vs 17.6%). For the entire cohort, the 3-, 5-, and 10-year progression-free survival (PFS) rates were 23%, 9%, and 3%, respectively, and the overall survival (OS) rates were 94%, 82%, and 76%, respectively. In the NoRT group, SRS was adjuvant treatment after resection in 38 patients (40.4%), salvage treatment for recurrent tumor treated with resection alone in 10 (10.6%), and not specified in 46 (48.9%). In the RT group, SRS was boost treatment in 9 patients (25.0%), salvage treatment after recurrence in 22 (61.1%), and not specified in 5 (13.9%). There was no difference between the two groups in terms of median PFS (24.0 months [Q1 34.0, Q3 15.0] vs 23.8 months [34.0, 18.0], respectively; p = 0.8) or median OS (293.0 months [not reached, 137.4] vs not reached [not reached, 48.0], respectively; p = 0.36). The adverse radiation effect rates were comparable between the groups (10.9% vs 17.6%, respectively; p = 0.4).

CONCLUSIONS

The role of SRS in the management of skull base chordomas is still evolving. This systematic literature review of biopsy-proven chordoma revealed that tumor control and survival rates for SRS alone after chordoma surgery were not inferior to those encountered after SRS plus fractionated RT.

Multi-spectral immunofluorescence evaluation of the myeloid, T cell, and natural killer cell tumor immune microenvironment in chordoma may guide immunotherapeutic strategies

Background

Chordoma is a rare, invasive, and devastating bone malignancy of residual notochord tissue that arises at the skull base, sacrum, or spine. In order to maximize immunotherapeutic approaches as a potential treatment strategy in chordoma it is important to fully characterize the tumor immune microenvironment (TIME). Multispectral immunofluorescence (MIF) allows for comprehensive evaluation of tumor compartments, molecular co-expression, and immune cell spatial relationships. Here we implement MIF to define the myeloid, T cell, and natural killer (NK) cell compartments in an effort to guide rational design of immunotherapeutic strategies for chordoma.

Methods

Chordoma tumor tissue from 57 patients was evaluated using MIF. Three panels were validated to assess myeloid cell, T cell, and NK cell populations. Slides were stained using an automated system and HALO software objective analysis was utilized for quantitative immune cell density and spatial comparisons between tumor and stroma compartments.

Results

Chordoma TIME analysis revealed macrophage infiltration of the tumor parenchyma at a significantly higher density than stroma. In contrast, helper T cells, cytotoxic T cells, and T regulatory cells were significantly more abundant in stroma versus tumor. T cell compartment infiltration more commonly demonstrated a tumor parenchymal exclusion pattern, most markedly among cytotoxic T cells. NK cells were sparsely found within the chordoma TIME and few were in an activated state. No immune composition differences were seen in chordomas originating from diverse anatomic sites or between those resected at primary versus advanced disease stage.

Conclusion

This is the first comprehensive evaluation of the chordoma TIME including myeloid, T cell, and NK cell appraisal using MIF. Our findings demonstrate that myeloid cells significantly infiltrate chordoma tumor parenchyma while T cells tend to be tumor parenchymal excluded with high stromal infiltration. On average, myeloid cells are found nearer to target tumor cells than T cells, potentially resulting in restriction of T effector cell function. This study suggests that future immunotherapy combinations for chordoma should be aimed at decreasing myeloid cell suppressive function while enhancing cytotoxic T cell and NK cell killing.

Rare germline variants in PALB2 and BRCA2 in familial and sporadic chordoma

Chordoma is a rare bone tumor with genetic risk factors largely unknown. We conducted a whole-exome sequencing (WES) analysis of germline DNA from 19 familial chordoma cases in five pedigrees and 137 sporadic chordoma patients and identified 17 rare germline variants in PALB2 and BRCA2, whose products play essential roles in homologous recombination (HR) and tumor suppression. One PALB2 variant showed disease cosegregation in a family with four affected people or obligate gene carrier. Chordoma cases had a significantly increased burden of rare variants in both genes when compared to population-based controls. Four of the six PALB2 variants identified from chordoma patients modestly affected HR function and three of the 11 BRCA2 variants caused loss of function in experimental assays. These results, together with previous reports of abnormal morphology and Brachyury expression of the notochord in Palb2 knockout mouse embryos and genomic signatures associated with HR defect and HR gene mutations in advanced chordomas, suggest that germline mutations in PALB2 and BRCA2 may increase chordoma susceptibility. Our data shed light on the etiology of chordoma and support the previous finding that PARP-1 inhibitors may be a potential therapy for some chordoma patients.

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.

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

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

High dose image-guided, intensity modulated radiation therapy (IG-IMRT) for chordomas of the sacrum, mobile spine and skull base: preliminary outcomes

PURPOSE

To report preliminary outcomes of high dose image-guided intensity modulated radiotherapy (IG-IMRT) in the treatment of chordomas of the sacrum, mobile spine and skull base.

METHODS

Retrospective analysis of chordoma patients treated with surgery and/or radiotherapy (RT) in a single tertiary cancer center. Initial treatment was categorized as (A) Adjuvant or definitive high-dose RT (78 Gy/39fx or 24 Gy/1fx) vs (B) surgery-only or low dose RT. The primary endpoint was the cumulative incidence of local failure.

RESULTS

A total of 31 patients were treated from 2010 through 2020. Median age was 55 years, tumor location was 64% sacrum, 13% lumbar, 16% cervical and 6% clivus. Median tumor volume was 148 cc (8.3 cm in largest diameter), 42% of patients received curative-intent surgery and 65% received primary RT (adjuvant or definitive). 5-year cumulative incidence of local failure was 48% in group A vs 83% in group B (p = 0.041). Tumor size > 330 cc was associated with local failure (SHR 2.2, 95% CI 1.12 to 7.45; p = 0.028). Eight patients developed distant metastases, with a median metastases-free survival of 56.1 months. 5-year survival for patients that received high dose RT was 72% vs 76% in patients that received no or low dose RT (p = 0.63).

CONCLUSION

Our study suggests high-dose photon IG-IMRT improves local control in the initial management of chordomas. Health systems should promote reference centers with clinical expertise and technical capabilities to improve outcomes for this complex disease.

Ectopic Recurrence of Skull Base Chordoma after Proton Therapy

Simple Summary

Chordoma are very rare tumors of the spine and skull base. Due to close proximity of crucial organs, like the brain stem, complete removal can often not be achieved, and tumor tissue, either macroscopic or microscopic, remains in situ. Local recurrence up to 88% occurs in 10 years. Ectopic recurrence as an early sign of treatment failure is considered rare. We retrospectively reviewed five patients with ectopic recurrence as a first sign of treatment failure after treatment with surgery and proton therapy, and studied the applied treatment strategies and imaging follow-up. We found 18 ectopic recurrences in these five patients, of which 17 (94%) could be related to prior surgical tracts. Our theory is that these relapses occur due to microscopic tumor spill during surgery. These cells did not receive a therapeutic radiation dose. Advances in surgical possibilities and adjusted radiotherapy target volumes might improve local control and survival.

Abstract

Background: Chordoma are rare tumors of the axial skeleton. The treatment gold standard is surgery, followed by particle radiotherapy. Total resection is usually not achievable in skull base chordoma (SBC) and high recurrence rates are reported. Ectopic recurrence as a first sign of treatment failure is considered rare. Favorable sites of these ectopic recurrences remain unknown. Methods: Five out of 16 SBC patients treated with proton therapy and surgical resection developed ectopic recurrence as a first sign of treatment failure were critically analyzed regarding prior surgery, radiotherapy, and recurrences at follow-up imaging. Results: Eighteen recurrences were defined in five patients. A total of 31 surgeries were performed for primary tumors and recurrences. Seventeen out of eighteen (94%) ectopic recurrences could be related to prior surgical tracts, outside the therapeutic radiation dose. Follow-up imaging showed that tumor recurrence was difficult to distinguish from radiation necrosis and anatomical changes due to surgery. Conclusions: In our cohort, we found uncommon ectopic recurrences in the surgical tract. Our theory is that these recurrences are due to microscopic tumor spill during surgery. These cells did not receive a therapeutic radiation dose. Advances in surgical possibilities and adjusted radiotherapy target volumes might improve local control and survival.

Dramatic In Vivo Efficacy of the EZH2-Inhibitor Tazemetostat in PBRM1-Mutated Human Chordoma Xenograft

Simple Summary

Chordomas are rare bone tumors characterized by a high recurrence rate. Presently, no medical treatment is available for advanced diseases due to the lack of molecular data and preclinical models. The current study showed the establishment and characterization of the largest panel chordoma xenografts, allowing pharmacological studies. In one PBRM1-mutated model, we demonstrated a strong therapeutic efficacy of the EZH2-inhibitor tazemetostat, encouraging further research on EZH2-inhibitors in chordomas.

Abstract

Chordomas are rare neoplasms characterized by a high recurrence rate and a poor long-term prognosis. Considering their chemo-/radio-resistance, alternative treatment strategies are strongly required, but their development is limited by the paucity of relevant preclinical models. Mutations affecting genes of the SWI/SNF complexes are frequently found in chordomas, suggesting a potential therapeutic effect of epigenetic regulators in this pathology. Twelve PDX models were established and characterized on histological and biomolecular features. Patients whose tumors were able to grow into mice had a statistically significant lower progression-free survival than those whose tumors did not grow after in vivo transplantation (p = 0.007). All PDXs maintained the same histopathological features as patients’ tumors. Homozygous deletions of CDKN2A/2B (58.3%) and PBRM1 (25%) variants were the most common genomic alterations found. In the tazemetostat treated PDX model harboring a PBRM1 variant, an overall survival of 100% was observed. Our panel of chordoma PDXs represents a useful preclinical tool for both pharmacologic and biological assessments. The first demonstration of a high antitumor activity of tazemetostat in a PDX model harboring a PBRM1 variant supports further evaluation for EZH2-inhibitors in this subgroup of chordomas.

Notochordal Cell-Based Treatment Strategies and Their Potential in Intervertebral Disc Regeneration

Chronic low back pain is the number one cause of years lived with disability. In about 40% of patients, chronic lower back pain is related to intervertebral disc (IVD) degeneration. The standard-of-care focuses on symptomatic relief, while surgery is the last resort. Emerging therapeutic strategies target the underlying cause of IVD degeneration and increasingly focus on the relatively overlooked notochordal cells (NCs). NCs are derived from the notochord and once the notochord regresses they remain in the core of the developing IVD, the nucleus pulposus. The large vacuolated NCs rapidly decline after birth and are replaced by the smaller nucleus pulposus cells with maturation, ageing, and degeneration. Here, we provide an update on the journey of NCs and discuss the cell markers and tools that can be used to study their fate and regenerative capacity. We review the therapeutic potential of NCs for the treatment of IVD-related lower back pain and outline important future directions in this area. Promising studies indicate that NCs and their secretome exerts regenerative effects, via increased proliferation, extracellular matrix production, and anti-inflammatory effects. Reports on NC-like cells derived from embryonic- or induced pluripotent-stem cells claim to have successfully generated NC-like cells but did not compare them with native NCs for phenotypic markers or in terms of their regenerative capacity. Altogether, this is an emerging and active field of research with exciting possibilities. NC-based studies demonstrate that cues from developmental biology can pave the path for future clinical therapies focused on regenerating the diseased IVD.

Surgical management of a thoracic chordoma: A case report and literature review

Background:

Chordomas are rare benign, but locally aggressive tumors that are regularly encountered in the clivus and sacrum. Although they are rarely found in the thoracic spine, they can contribute not only to local bone destruction and spinal instability, lead to cord compression, and major neurological deficits.

Case Description:

A 56 year-old-male originally underwent a T12 laminectomy with debulking for a thoracic chordoma. Two years later, the lesion recurred contributing to a significant paraparesis. The new MR showed a T2 hyper intense lesion with huge epidural extension that warranted a 360° surgical decompression and fusion. The histopathology from both surgeries confirmed the diagnosis of a chordoma.

Conclusion:

Combined 360° decompression and fusion was warranted to resect a T12 chordoma that recurred 2 years following an original laminectomy with debulking procedure.

Multimodal Intraoperative Image-Driven Surgery for Skull Base Chordomas and Chondrosarcomas

Given the difficulty and importance of achieving maximal resection in chordomas and chondrosarcomas, all available tools offered by modern neurosurgery are to be deployed for planning and resection of these complex lesions. As demonstrated by the review of our series of skull base chordoma and chondrosarcoma resections in the Advanced Multimodality Image-Guided Operating (AMIGO) suite, as well as by the recently published literature, we describe the use of advanced multimodality intraoperative imaging and neuronavigation as pivotal to successful radical resection of these skull base lesions while preventing and managing eventual complications.

Contemporary surgical management of skull base chordomas - anatomical reflections on a single center experience retrospective case series

Chordoma, a rare, locally aggressive tumor can affect the central skull base, usually centered at the midline. Complete surgical resection remains mainstay of therapy in case of primary as well as recurrent tumors. Owing to their secluded location, surgical resection of skull base chordomas remains a challenge, even though the recent advancement of endoscopic endonasal approaches has had a significant positive impact on the management of these patients. Endoscopic endonasal approaches have been shown to significantly reduce surgical morbidity when compared to traditional open approaches, however the classical endoscopic transclival midline approach fails to sufficiently expose parts of many skull base chordomas. More recent refinements of the technique, such as the interdural pituitary transposition and posterior clinoidectomy, the transpterygoid plate approach and the transcondylar far medial (TFM) approach enable the surgeon the increase the resection rate in these patients. This retrospective case series focuses on anatomical aspects in the surgical management of patients with skull base chordomas. We outline the surgical anatomy of contemporary endoscopic approaches to the skull base based intraoperative illustrations as well as pre- and postoperative 3D reconstructed CT and MR images if our patients. This article should help the clinical choose the most appropriate approach and be aware of relevant anatomy as well as potential shortcomings of a given approach.