Prognostic factors of sacral chordoma after surgical therapy: a study of 36 patients

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.

A Bibliometric Analysis of the 20 Most Cited Articles on Sacrococcygeal Chordomas

This study aims to summarize sacrococcygeal chordoma literature through bibliometric analysis and to offer insights into key studies to guide clinical practices and future research. The Web of Science database was searched using the terms "sacral chordoma", "chordomas of the sacrum", "chordomas of the sacral spine", "chordomas of the sacrococcygeal region", "coccygeal chordoma", and "coccyx chordoma". Articles were analyzed for citation count, authorship, publication date, journal, research area tags, impact factor, and evidence level. The median number of citations was 75 (range: 53-306). The primary publication venue was the International Journal of Radiation Oncology, Biology, Physics. Most works, published between 1999 and 2019, featured a median journal impact factor of 3.8 (range: 2.1-7) and predominantly fell under the research area tag, radiation, nuclear medicine, and imaging. Of these articles, 19 provided clinical data with predominantly level III evidence, and one was a literature review. This review highlights the increasing volume of sacrococcygeal chordoma publications over the past two decades, indicating evolving treatment methods and interdisciplinary patient care. Advances in radiation, particularly intensity-modulated radiation therapy (IMRT) and proton beam therapy, are believed to be propelling research growth, and the lack of level I evidence underscores the need for more rigorous studies to refine treatment protocols for sacrococcygeal chordomas.

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.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

Construction of a Tool to Predict Overall Survival of Patients With Primary Spinal Tumors After Surgical Resection: A Real-World Analysis Based on the Surveillance, Epidemiology, and End Results Database

BACKGROUND

We aim to construct a practical clinical prediction model to accurately evaluate the overall survival (OS) of patients with primary spinal tumors after primary tumor resection, thereby aiding clinical decision-making.

METHODS

A total of 695 patients diagnosed with a primary spinal tumor, selected from the Surveillance, Epidemiology, and End Results (SEER) database, were included in this study. The Cox regression algorithm was applied to the training cohort to build the prognostic nomogram model. The nomogram's performance in terms of discrimination, calibration, and clinical usefulness was also assessed in the internal SEER validation cohort. The fitted prognostic nomogram was then used to create a web-based calculator.

RESULTS

Four independent prognostic factors were identified to establish a nomogram model for patients with primary spinal tumors who had undergone surgical resection. The C-index (.757 for the training cohort and .681 for the validation cohort) and the area under the curve values over time (both >.68) showed that the model exhibited satisfactory discrimination in both the SEER cohort. The calibration curve revealed that the projected and actual survival rates are very similar. The decision curve analysis also revealed that the model is clinically valuable and capable of identifying high-risk patients.

CONCLUSIONS

After developing a nomogram and a web-based calculator, we were able to reliably forecast the postoperative OS of patients with primary spinal tumors. These tools are expected to play an important role in clinical practice, informing clinicians in making decisions about patient care after surgery.

Cervical Paraspinal Chordoma: A Literature Review with a Novel Case Report

Chordomas are rare malignant neoplasms, accounting for 1–4% of all primary bone tumors. Most spinal chordomas occur in the sacrococcygeal region and the base of the skull; however, 6% of chordomas are observed in the cervical spine. In these cases, the lesion is mainly located in the midline. These tumors slowly grow before becoming symptomatic and encase the surrounding vascular and nerve structures. Patients with advanced chordoma have a poor prognosis due to local recurrence with infiltration and destruction of adjacent bone and tissues. Systemic chemotherapy options have not been fully effective in these tumors, especially for recurrent chordomas. Thus, new combinations of currently available targeted molecular and biological therapies with radiotherapy have been proposed as potential treatment modalities. Here, the present paper describes the case of a 41-year-old male with a C2–C4 chordoma located paravertebrally, who underwent surgical resection with a debulking procedure for a cervical chordoma. Computed tomography angiography revealed a paraspinal mass with bone remodeling and the MRI showed a paravertebral mass penetrating to the spinal canal with a widening of the intervertebral C2–C3 foramen. Initially, the tumor was diagnosed as schwannoma based on its localization and imaging features; however, the histopathology specimen confirmed the diagnosis of chordoma. This case study highlights the effectivity of radical surgical resection as a mainstay treatment for chordomas, discusses neuroimaging, diagnosis, and the use of currently available targeted therapies and forthcoming treatment strategies, as alternative treatment options for chordoma.

Long Non-Coding RNA MDFIC-7 Promotes Chordoma Progression Through Modulating the miR-525-5p/ARF6 Axis

Background

Chordoma, an extremely rare malignant tumor, remains difficult to be cured because of its strong local invasiveness and high recurrence rate. Long non-coding RNAs (lncRNAs) have been demonstrated to play multiple roles in various cancers. The purpose of this study was to investigate the modulatory function of lncRNA MDFIC-7 in chordoma and to elucidate its underlying mechanisms.

Methods

Quantitative real-time polymerase chain reaction was performed to detect the expression of lncRNA MDFIC-7 in tumor tissues and adjacent nontumorous tissues collected from 15 chordoma patients, as well as in chordoma cell lines. Gene silencing and overexpression experiments were carried out by RNA interference and lentiviral transduction. The effect of lncRNA MDFIC-7 on the proliferation of chordoma cells was evaluated by cell counting kit-8 assay, colony formation assay and xenograft tumor experiments. RNA immunoprecipitation and dual luciferase reporter assays were conducted to evaluate the binding between lncRNA MDFIC-7 and miRNA-525-5p and the interaction between miR-525-5p and the 3′ untranslated region of ADP-ribosylation factor 6 (ARF6) mRNA. The glycolytic capacity and mitochondrial function of chordoma cells were measured by the Seahorse Bioscience XF96 Extracellular Flux Analyzer.

Results

The expression of lncRNA MDFIC-7 was higher in chordoma tumor tissues than in adjacent non-tumor tissues. Downregulation of lncRNA MDFIC-7 reduced colony formation and cell proliferation in chordoma cells and decreased xenograft tumor growth in a nude mouse model. Moreover, lncRNA MDFIC-7 knockdown attenuated the Warburg effect in chordoma cells and xenograft tumors. LncRNA MDFIC-7 knockdown elevated miR-525-5p levels and decreased ARF6 expressions. Overexpression of ARF6 reversed the inhibitory effect of lncRNA MDFIC-7 knockdown on cell proliferation and the Warburg effect in chordoma cells and xenograft tumors. Mechanistically, lncRNA MDFIC-7, as a molecular sponge of miR-525-5p, negatively regulated miR-525-5p expression and promoted the gene expression of ARF6, a miR-525-5p target.

Conclusion

Our findings demonstrate that lncRNA MDFIC-7 acts as a molecular sponge to competitively bind to miR-525-5p and promote expression of ARF6. The lncRNA MDFIC-7/miR-525-5p/ARF6 axis regulates chordoma progression and the Warburg effect in chordoma, suggesting that lncRNA MDFIC-7 and miR-525-5p could be promising therapeutic targets for the treatment of chordoma.

Genes Predicting Survival of Chordoma Patients

BACKGROUND

A chordoma is a slow-growing, invasive neoplasm in the neuraxis that is thought to arise from notochordal cells. At 10-year follow-up, the average survival rate is 50%, though individual prognosis varies substantially. We aimed to provide a comprehensive overview of the genes and proteins expressed in these tumors and their prognostic value to facilitate prognostication for patients with chordoma.

METHODS

A systematic search of clinical studies that investigated expressed factors related to chordoma survival was performed in PubMed. Data extracted included RNA and protein expression data and prognostic value (in terms of overall survival, progression-free survival, disease-free survival, and recurrence-free survival) from univariate and multivariate analyses.

RESULTS

This review included 78 original studies that collectively evaluated 134 expressed factors. Of these molecular factors, 96 by univariate analysis and 32 by multivariate analysis had a predictive value for patient survival. Of the molecular factors studied in multivariate analyses, 26 factors had a negative effect while 6 had a positive effect on patient survival.

CONCLUSIONS

Identification of molecular factors that are associated with survival contributes to better prognostication of patients with chordoma. Given the rarity of chordoma, often only univariate analyses can be performed. Robust multivariate analyses are scarcer but provide independently significant prognostic factors. The data presented in this review can aid in prognostication for the individual patient and facilitate the development of targeted therapies.

Surgical Management of Spinal Chordoma: A Systematic Review and Single-Center Experience

OBJECTIVE

Chordoma is a rare neoplasm of the neuraxis derived from remnants of the primitive notochord. The importance of wide margins and use of adjuvant therapy in spinal chordomas are still contentious points in the management of spinal chordomas. We conducted a systematic review of the surgical management of spinal chordomas alongside our 10-year institutional experience.

METHODS

A systematic search of the literature was performed in November 2020 using Embase and MEDLINE for articles regarding the surgical management of chordomas arising from the mobile spine and sacrum. We also searched for all adult patients who were surgically managed for spinal chordomas at our institute between 2010 and 2020. In both the systematic review and our institutional case series, data on adequacy of resection, use of adjuvant therapy, complications, recurrence (local or metastatic), and survival outcomes were collected.

RESULTS

We identified and analyzed 42 articles, yielding 1531 patients, from which the overall gross total or wide resection rate was 54.9%. Among the 8 cases in our institutional experience (4 sacral, 3 cervical, and 1 lumbar), we achieved gross total resection in 50% of initial operations. The recurrence rate was 25% in our gross total resection group and 50% where initial resection was subtotal. Of patients, 75% had no evidence of recurrence at most recent follow-up.

CONCLUSIONS

Albeit difficult at times because of the proximity to neurovascular tissue, achieving a wide resection followed by adjuvant therapy for spinal chordomas is of great importance. Multidisciplinary discussion is valuable to ensure the best outcome for the patient.

Clinicopathological and Prognostic Characteristics in Dedifferentiated/Poorly Differentiated Chordomas: A Pooled Analysis of Individual Patient Data From 58 Studies and Comparison With Conventional Chordomas

Background

Currently, the clinicopathological and prognostic characteristics of dedifferentiated chordoma (DC) and poorly differentiated chordoma (PDC) remain poorly understood. In this study, we sought to characterize clinicopathological parameters in a large PDC/DC cohort and determine their correlations with progression-free survival (PFS) and overall survival (OS) of patients. We also attempted to compare clinical features between PDC/DC and conventional chordoma (CC).

Methods

Literature searches (from inception to June 01, 2020) using Medline, Embase, Google Scholar and Wanfang databases were conducted to identify eligible studies according to predefined criteria. The local database at our center was also retrospectively reviewed to include CC patients for comparative analysis.

Results

Fifty-eight studies from the literature and 90 CC patients from our local institute were identified; in total, 54 PDC patients and 96 DC patients were analyzed. Overall, PDC or DC had distinct characteristics from CC, while PDC and DC shared similar clinical features. Adjuvant radiotherapy and chemotherapy were associated with both PFS and OS in PDC patients in the univariate and/or multivariate analyses. In the DC cohort, tumor resection type, adjuvant chemotherapy and tumor dedifferentiation components significantly affected PFS, whereas none of them were predictive of outcome in the multivariate analysis. By analyzing OS, we found that surgery, resection type and the time to dedifferentiation predicted the survival of DC patients; however, only surgery remained significant after adjusting for other covariables.

Conclusions

These data may offer useful information to better understand the clinical characteristics of PDC/DC and may be helpful in improving the outcome prediction of patients.

Clinical Outcome of Sacral Chordoma Patients Treated with Pencil Beam Scanning Proton Therapy

AIMS

Sacral chordomas are locally aggressive, radio-resistant tumours. Proton therapy has the potential to deliver high radiation doses, which may improve the therapeutic ratio when compared with conventional radiotherapy. We assessed tumour control and radiation-induced toxicity in a cohort of sacral chordoma patients treated with definitive or postoperative pencil beam scanning proton therapy.

METHODS AND MATERIALS

Sixty patients with histologically proven sacral chordoma treated between November 1997 and October 2018 at the Paul Scherrer Institute with postoperative (n = 50) or definitive proton therapy (n = 10) were retrospectively analysed. Only 10 (17%) patients received combined photon radiotherapy and proton therapy. Survival rates were calculated using the Kaplan-Meier actuarial method. The Log-rank test was used to compare different functions for local control, freedom from distant recurrence and overall survival. Acute and late toxicity were assessed according to the Common Terminology Criteria for Adverse Events (CTCAE) v5.0.

RESULTS

The median follow-up was 48 months (range 4-186). Local recurrence occurred in 20 (33%) patients. The 4-year local control, freedom from distant recurrence and overall survival rates were 77%, 89% and 85%, respectively. On univariate analysis, subtotal resection/biopsy (P = 0.02), tumour extension restricted to bone (P = 0.01) and gross tumour volume >130 ml (P = 0.04) were significant predictors for local recurrence. On multivariate analysis, tumour extension restricted to bone (P = 0.004) and gross total resection (P = 0.02) remained independent favourable prognostic factors for local recurrence. Twenty-four (40%), 28 (47%) and eight (11%) patients experienced acute grade 1, 2 and 3 toxicities, respectively. The 4-year late toxicity-free survival was 91%. Two patients developed secondary malignancies to the bladder 3-7 years after proton therapy.

CONCLUSIONS

Our data indicate that pencil beam scanning proton therapy for sacral chordomas is both safe and effective. Gross total resection, tumour volume <130 ml and tumour restricted to the bone are favourable prognostic factors for local tumour control.

Sacroplasty Augmentation of Instrumented Pelvic Reconstruction After High Sacrectomy: A Technical Case Report

BACKGROUND AND IMPORTANCE

En bloc resection of sacral tumors is the most effective treatment to help prevent recurrence. Sacrectomy, however, can be destabilizing, depending on the extent of resection. Various surgical techniques for improving stability and enabling early ambulation have been proposed.

CLINICAL PRESENTATION

Here, we report a case in which we use PMMA (poly[methyl methacrylate]) to augment pelvic instrumentation to improve mechanical stability after sacrectomy for en bloc resection of a solitary fibrous tumor.

CONCLUSION

We highlight the use of sacroplasty augmentation of pelvic ring reconstruction to provide biomechanical stability without the need for fusion of any mobile spine segments, which allowed for early patient ambulation and no appreciable loss of range of motion or mobility.

Chordoma-Current Understanding and Modern Treatment Paradigms

Chordoma is a low-grade notochordal tumor of the skull base, mobile spine and sacrum which behaves malignantly and confers a poor prognosis despite indolent growth patterns. These tumors often present late in the disease course, tend to encapsulate adjacent neurovascular anatomy, seed resection cavities, recur locally and respond poorly to radiotherapy and conventional chemotherapy, all of which make chordomas challenging to treat. Extent of surgical resection and adequacy of surgical margins are the most important prognostic factors and thus patients with chordoma should be cared for by a highly experienced, multi-disciplinary surgical team in a quaternary center. Ongoing research into the molecular pathophysiology of chordoma has led to the discovery of several pathways that may serve as potential targets for molecular therapy, including a multitude of receptor tyrosine kinases (e.g., platelet-derived growth factor receptor [PDGFR], epidermal growth factor receptor [EGFR]), downstream cascades (e.g., phosphoinositide 3-kinase [PI3K]/protein kinase B [Akt]/mechanistic target of rapamycin [mTOR]), brachyury—a transcription factor expressed ubiquitously in chordoma but not in other tissues—and the fibroblast growth factor [FGF]/mitogen-activated protein kinase kinase [MEK]/extracellular signal-regulated kinase [ERK] pathway. In this review article, the pathophysiology, diagnosis and modern treatment paradigms of chordoma will be discussed with an emphasis on the ongoing research and advances in the field that may lead to improved outcomes for patients with this challenging disease.

Surgical management of chordoma: A systematic review

Context: Chordomas are rare primary tumors of bone characterized by local aggressiveness and poor prognosis. The surgical exeresis plays a critical role for their management. Objective: The aim was to provide an overview of the surgical management of chordomas of the mobile spine and sacrum, describing the most common surgical approaches, the role of surgical margins, the difficulties of en block resection, the outcomes of surgery, the recurrence rate and the use of associated therapies. Methods: We performed a systematic search using the keywords "chordoma" in combination with "surgery", "spine", "sacrum" and "radiotherapy". Results: Fifty-eight studies, describing 1359 patients with diagnosis of chordoma were retrieved. 17 studies were performed on subjects with cervical chordomas and 49 focused on patients with sacrococcygeal chordomas. The remaining studies included patients with chordomas in cranial region and/or mobile spine and/or sacroccygeal region. The recurrence rate ranged from 25% to 60% for cervical chordomas, and from 18% to 89% for sacrococcygeal chordomas. Conclusion: Despite the remarkable advances in the local management of chordoma performed in the last decades, the current results of surgery alone are still unsatisfactory. The radical en bloc excision of tumour is technically demanding, particularly in the cervical spine. Although radical surgery must still be considered the gold standard for the management of chordomas, a multidisciplinary approach is required to improve the local control of the disease in patients who undergo both radical and non-radical surgery. Adjuvant radiation therapy increases the continuous disease-free survival and the local recurrence-free survival. Level of evidence: Systematic review; level III.

Long Noncoding RNA LINC00525 Promotes the Aggressive Phenotype of Chordoma Through Acting as a microRNA-505-3p Sponge and Consequently Raising HMGB1 Expression

Purposes

Long intergenic non-protein coding RNA 525 (LINC00525), a long noncoding RNA, has been implicated in the carcinogenesis and progression of many human cancer types. However, the detailed roles of LINC00525 in chordoma and the underlying mechanisms are not fully understood. Here, we aimed to determine whether LINC00525 could modulate the oncogenicity of chordoma cells and to elucidate in detail the molecular events underlying these tumor-promoting activities.

Methods

Reverse-transcription quantitative polymerase chain reactions were performed to assess LINC00525 expression in chordoma. The effects of LINC00525 silencing on chordoma cell proliferation, apoptosis, migration, and invasiveness in vitro and tumor growth in vivo were respectively tested using CCK-8 assay, flow cytometry, migration and invasion assays, and xenograft experiments.

Results

High LINC00525 expression levels were detected in chordoma tissues. The proliferative, migratory, and invasive abilities of chordoma cells in vitro and their tumor growth in vivo were suppressed by the LINC00525 knockdown, whereas apoptosis was induced by it. Mechanistically, LINC00525 acted as a molecular sponge of microRNA-505-3p (miR-505-3p) and upregulated the expression of high mobility group box 1 (HMGB1), which is directly targeted by miR-505-3p. Rescue assays indicated that increasing the output of miR-505-3p-HMGB1 axis attenuated the effects of LINC00525 depletion on chordoma cells.

Conclusion

LINC00525, a pro-oncogenic long noncoding RNA, promotes chordoma progression by regulating the miR-505-3p-HMGB1 axis. The LINC00525-miR-505-3p-HMGB1 pathway may be a novel therapeutic target in chordoma.

Comparison of Wide Margin and Inadequate Margin for Recurrence in Sacral Chordoma: A Meta-Analysis

STUDY DESIGN

.: A meta-analysis.

OBJECTIVE

.: The goal of this study was to accurately evaluate the risk ratio (RR) of recurrence in chordoma patients with wide margin after removing the tumors using surgery, compared with inadequate margin (intralesional or marginal).

SUMMARY OF BACKGROUND DATA

.: As a rare malignant bone cancer, the more effective treatment for sacral chordoma is still surgical resection. However, there is no convincing evidence and risk ratio about sacral chordoma patients would be benefit from which kind of surgical margin.

METHODS

.: We searched the PubMed, Cochrane Library, Web of Science, and EMBASE from inception to December 2018. The heterogeneity analysis and calculation of the pooled risk ratio were performed using RevMan 5.3 software. The assessment of publication bias and sensitivity analysis was conducted using StataSE 15.1 software. The protocol for this meta-analysis was registered on International prospective register of systematic reviews (PROSPERO, CRD42019127441).

RESULTS

.: Twelve studies with a total of 436 patients who met the inclusion criteria were included. The pooled results indicated that patients in the wide group had lower recurrence rate than those in the inadequate group (RR = 0.42, 95% confidence interval [CI] 0.31-0.57; P < 0.001). And patients in the wide group had lower mortality rate than those in the inadequate group (RR = 0.49, 95% CI 0.26-0.91; P = 0.02). No significant differences in the risk of mortality were found between relapsed patients in the two groups (RR = 0.64, 95% CI 0.35-1.15; P = 0.13).

CONCLUSION

.: In sacral chordoma patients, wide margin is associated with low recurrence risk, when it is feasible, a wide excision should be considered appropriate for sacrum chordoma.

LEVEL OF EVIDENCE

2.

Recurrence or neurological loss? Resection mode selection for patients with large sacral chordoma: an analysis of prognostic factors and quality of life

BACKGROUND

Surgical resection represents the main therapeutic method for sacral chordoma, but plans for resection mode must weigh neurological loss against complete tumor excision, a difficult balance to strike. The purpose of this study was to provide useful information contributing to surgical decision making in sacral chordoma.

METHODS

A retrospective review was performed on 47 patients with large sacral chordoma. Prognostic factors affecting recurrence-free survival (RFS) and overall survival (OS) were analyzed using the Kaplan-Meier method and Cox proportional hazards model. Quality of life was assessed by the Functional Assessment of Cancer Therapy-General (FACT-G) questionnaire and compared using Student's t test.

RESULTS

Resection mode was the independent prognostic factor affecting RFS, while independent prognostic factors affecting OS were resection mode and postoperative recurrence. As for quality of life, the en bloc resection group showed a higher score in emotional well-being, while the piecemeal resection group scored better in function well-being. No significant difference was identified in total the FACT-G score between two groups.

CONCLUSIONS

On the one hand, en bloc resection showed huge advantages in disease control for sacral chordoma. On the other hand, despite the unsatisfaction in functional well-being, en bloc resection did not sacrifice quality of life significantly in terms of the total FACT-G score.

Application of nomograms to predict overall and cancer-specific survival in patients with chordoma

Background

The survival prediction of patients with chordoma is difficult to make due to the rarity of this oncologic disease. Our objective was to apply a nomogram to predict survival outcomes in individuals with chordoma of the skull base, vertebral column, and pelvis.

Methods

A total of 558 patients with chordoma between 1973 and 2014 were collected from the Surveillance, Epidemiology, and End Results (SEER) database. Independent prognostic factors in patients with chordoma were identified via univariate and multivariate Cox analysis. Then these prognostic factors were incorporated into a nomogram to predict 3- and 5-year overall survival and cancer-specific survival rates. Internal and external data were used to validate the nomograms. Concordance indices (C-indices) were used to estimate the accuracy of this nomogram system.

Results

A total of 558 patients were randomly assigned into a training cohort (n = 372) and a validation cohort (n = 186). Age, surgical stage, tumor size, histology, primary site, and use of surgery were identified as independent prognostic factors via univariate and multivariate Cox analysis (all p < 0.05) and further included to establish the nomogram. The C-indices for overall survival and cancer-specific survival prediction of the training cohort were 0.775 (95% confidence interval, 0.770-0.779) and 0.756 (95% confidence interval, 0.749 -0.762). The calibration plots both showed an excellent consistency between actual survival and nomogram prediction.

Conclusion

Nomograms were constructed to predict overall survival and cancer-specific survival for patients with chordoma of the skull base, vertebral column, and pelvis. The nomogram could help surgeons to identify high risk of mortality and evaluate prognosis in patients with chordoma.

Conditional survival and changing risk profile in patients with chordoma: a population-based longitudinal cohort study

Objective

To evaluate the conditional survival of patients with chordoma to potentially help physician planning of optimal cancer surveillance and guide better clinical decisions.

Methods

In total, 1942 patients with chordoma were identified and extracted from Surveillance, Epidemiology, and End Results (SEER) databases (1973–2015). The cumulative survival estimates were used to calculate the conditional survival rate, and the Greenwood formula was used to estimate the 95% CI. In addition, multivariable Cox regression analyses were used to calculate hazard ratios, according to the duration of survival.

Results

The conditional 5-year disease-specific survival in patients with regional or localized chordoma was relatively stable over time, whereas in patients with distant chordoma, there was a gradual improvement. The conditional 5-year disease-specific survival (DSS) of patients older than 60 years old and patients with a tumor size between 5 and 10 cm improved. Interestingly, for patients with a tumor larger than 10 cm, the conditional 5-year DSS decreased over time. After surviving 5 years, the hazard ratio (HR) of patients older than 60 years old decreased from 1.33 to 1.24, that of patients with a tumor size between 5 and 10 cm decreased from 1.61 to 1.52 and that of patients with distant metastasis decreased from 3.30 to 1.09. However, after surviving 5 years, the HR of patients with a tumor size larger than 10 cm increased from 2.33 to 3.77, that of patients who underwent surgical resection increased from 0.37 to 0.58 and that of patients who received radiation therapy increased from 0.81 to 1.04.

Conclusion

Age at diagnosis, tumor size and disease stage can influence conditional survival for patients with chordoma. The HR of different factors will change over the survival time. Therefore, understanding the changing risk profile and conditional 5-year DSS of chordoma is critical for accurate clinical treatment guidance.

Sacral chordoma: a clinical review of 101 cases with 30-year experience in a single institution

BACKGROUND

Local recurrence rates are high in sacral chordoma patients. Adjuvant radiotherapy may play a role in increasing local control. Patients with locally recurrent tumors continue to comprise a significant proportion of the sacral chordoma population and appear to have worse prognosis than those with primary tumors. High-quality studies comparing presentation and treatments for primary and first local recurrent sacral chordoma tumors are sparse.

PURPOSE

To determine: whether there is a difference in how primary and tumors at first recurrence present; the overall survival, local relapse-free survival, and distant relapse-free survival rates and prognostic factors for patients presenting with a primary tumor; overall survival, local relapse-free survival, and distant relapse-free survival rates and prognostic factors for patients presenting with a first local relapse; if there any differences in overall survival, local relapse-free survival, and distant relapse-free survival rates between patients presenting with a primary tumor and those with a first local relapse.

STUDY DESIGN

Retrospective case series.

PATIENT SAMPLE

One hundred one sacral chordoma cases.

OUTCOME MEASURE

Overall survival, local relapse-free survival, and distant relapse-free survival rates.

METHODS

Between 1978 and 2013, 131 patients with sacral chordoma were seen. Of them, 17 patients (13%) presented with a history of more than one local recurrence. One patient (1%) presented with multiple distant metastases. Ten patients (8%) had less than 36 months of follow-up and had no event (eg, death, local recurrence, or distant metastasis). A total of 102 patients met our inclusion criteria: patients with primary or first recurrent tumors, without metastatic disease, who underwent surgery and with at least 36 months of follow-up. One patient (1%) died intraoperatively; therefore, 101 patients were included in the present analysis. Cox proportional hazards regression analysis was performed for primary and local recurrent tumor separately and to compare primary and local recurrent tumors.

RESULTS

We analyzed 73 primary and 28 first time recurrent sacral chordomas. Tumor size at presentation was different for primary and recurrent tumors (primary median size: 158 cm³, interquartile range [IQR]: 46-634; recurrent median size: 39 cm³, IQR: 14-175; p=.001). Overall survival at 5 and 10years for the primary tumors was 79% and 59%, respectively. Local relapse-free survival at 5years was 86%. For primary tumors, not receiving radiation was an independent predictor for worse local relapse-free survival (hazard ratio [HR]: 0.20; 95% confidence interval [CI]: 0.0043-0.90; p=.004) and increased tumor size was an independent predictor for both worse overall survival (HR: 1.68; 95% CI: 1.38-2.42; p=.004) and worse distant relapse-free survival (HR: 2.25; 95% CI: 1.47-3.44; p<.001). For recurrent tumors, the 5- and 10-year overall survival was 65% and 40%, respectively. Local relapse-free survival at 5years was 79% for recurrent tumors. On bivariate analysis, increased tumor size was a significant predictor for worse survival (LR median: 338 mL; IQR: 218-503 mL; no LR median: 26 mL; IQR: 9-71 mL). A trend was seen toward better distant relapse survival for tumors presenting as a primary tumor (HR: 0.51; 95% CI: 0.25-1.06; p=.072).

CONCLUSION

Using a combination of surgical resection and adjuvant radiotherapy allowed us to obtain a good overall survival, local relapse-free survival, and distant relapse-free survival in patients presenting with either a primary tumor or with a first time local recurrent tumor.

Local and Distant Recurrence in Resected Sacral Chordomas: A Systematic Review and Pooled Cohort Analysis

STUDY DESIGN

Systematic review.

OBJECTIVES

Sacral chordomas are rare, primary tumors of the spine, best treated with en bloc resection. The purpose of this study was to assess the literature for resected sacral chordoma and to quantify the prevalence of, risk factors for, and treatment outcomes of local and distant recurrence therein.

METHODS

We searched 5 online databases from January 1980 to May 2016 to find articles that report survival, recurrence outcomes, and/or prognostic factors for the resected sacral chordoma patient population. Characteristics and clinical outcomes of the pooled cohort are reported. Fisher exact tests, unpaired t tests, and one-way analysis of variance were used to investigate patient- and treatment-associated prognostic factors for local and distant recurrence. Survival analyses were performed for time to local recurrence and death. The protocol's PROSPERO ID is CRD42015024384.

RESULTS

Fifty-seven studies, with 1235 unique sacral chordoma patients, were included in this review. Local and distant recurrence occurred in 42.6% and 22.4% of patients with adequate follow-up, respectively. Kaplan-Meier overall median survival for patients with and without recurrence were 98 and 209 months after surgery, respectively. Wide surgical margin was associated with a lower rate of local recurrence; and wide surgical margin, female sex, and patient age ≥65 years were associated with lower rates of distant recurrence.

CONCLUSIONS

While surgical margin remains the most significant prognostic factor for local and distant recurrence, combined surgical approach may be associated with local recurrence. Male sex and age <65 years may be associated with distant recurrence. Patients with risk factors for recurrence should undergo close monitoring to maximize survival.

Maximizing Sacral Chordoma Resection by Precise 3-Dimensional Tumor Modeling in the Operating Room Using Intraoperative Computed Tomography Registration with Preoperative Magnetic Resonance Imaging Fusion and Intraoperative Neuronavigation: A Case Series

INTRODUCTION

The primary treatment for patients with sacral chordoma is en bloc surgical resection with negative margins, which has been shown to reduce local recurrence and tumor-related morbidity. Here we describe the use of intraoperative neuronavigation using preoperative spine magnetic resonance imaging fused to intraoperative computed tomography (CT) to create 3-dimensional tumor reconstructions in the operating room for intraoperative identification of bone and soft-tissue margins for maximal safe tumor resection.

METHODS

A single-institution retrospective chart review was completed to encompass our experience of 6 consecutive patients who had sacral chordoma resections using our described navigation protocol. We collected data on patient demographics, previous surgeries, radiation therapy, preoperative examination, spinal levels involved, dural involvement, estimated blood loss, surgery time, tissue diagnosis, follow-up, postoperative examination, complications, and recurrence. Primary outcome was en bloc resection with negative margins as planned preoperatively.

RESULTS

Negative surgical margins were achieved in 5 of 5 patients, who were preoperatively planned for en bloc resection with negative margins. The most common levels involved were S4-S5. All patients had a stable or improved neurologic examination after en bloc surgical resection. The average follow-up was 5.4 months ± 84.6 days. No patient had residual or recurrent tumor at last follow-up.

CONCLUSIONS

Magnetic resonance imaging-CT fusion and 3-dimensional reconstruction techniques using an intraoperative CT scanner with image-guided navigation to aid preoperative planning and surgical resection of sacral chordomas are not well represented in the literature. This technique can be used for planning en bloc surgical resections and for more precisely identifying tumor margins intraoperatively.

The clinical outcome of recurrent sacral chordoma with further surgical treatment

To analyze the clinical results and related factors of further surgical treatment for recurrent sacral chordomas.Chordomas are rare primary malignant tumors with a high recurrence rate. The treatment of recurrent tumors is difficult and controversial. Contamination by previous operations and disturbed local anatomical structures may increase the risk of reoperation. Most previous studies have focused on the primary tumor; there are very few reports on the clinical diagnosis, treatment, and prognosis of recurrent sacral chordomas.Thirty-four patients with recurrent sacral chordomas from 1979 to 2014 were included in this study. The patients comprised 25 men and 9 women with an average age of 50.7 (24-75) years. The average time until recurrence was 19.4 (4-51) months postoperatively, and 85.3% of the recurrent tumors were located in bone. The patients had an average of 1.2 (1-3) recurrences before further operations were performed in our hospital. The mean maximum tumor diameter was 8.1 (4.6-12.0) cm. Thirty-one patients underwent further tumor resection in our hospital. The postoperative recurrence, metastasis, and survival results were followed and analyzed.The mean follow-up after surgical treatment of recurrence was 49.6 (12-144) months. Nine patients (37.5%) developed recurrence again after an average of 26.7 months. The 3-year and 5-year recurrence-free survival rate was 69.4% and 63.1%, respectively. Multivariate analysis showed that the tumor level within the sacrum (P = .001) and the surgical margin (P = .001) were significant recurrence-related factors. Four patients (16.7%) developed lung metastasis. Eighteen patients were alive at last follow-up. The 5-year and 10-year survival rate after surgical treatment of recurrence was 67.3% and 53.9%, respectively.Most recurrent tumors are located in bone, and a safe osteotomy margin is important. The surgical margin is the only controllable factor of further tumor recurrence. Some patients with recurrence achieve long survival and obtain a clinical benefit from repeated operations if complete resection is achieved.

Adjuvant gamma knife surgery and image-guided, intensity-modulated radiation therapy for the treatment of sacral chordomas

Aim

The aim of this study was to confirm whether patients with sacral chordoma benefit from adjuvant radiotherapy and to determine the optimal photon radiotherapy module for comprehensive treatment.

Background

Chordoma is a rare slow-growing neoplasm arisen from cellular remnants of the notochord. About 50% occur in the sacrococcygeal region. Surgical resection and adjuvant radiation therapy are recommended treatment due to the improving local control rate.

Materials and methods

118 patients treated by surgery and adjuvant radiotherapy from August 2003 to May 2015 were retrospectively analyzed. All patients received surgical resection after diagnosis. Among these patients, 44 were treated by exclusive surgery, and 48 were treated with adjuvant image-guided, intensity-modulated radiation therapy (IG-IMRT). In addition, 26 patients were treated with gamma knife surgery (GKS) after surgical resection. The median follow-up was 54 months for all patients. Kaplan-Meier analysis was used to calculate recurrence-free survival (RFS) overall survival (OS).

Results

Patients treated with adjuvant radiotherapy had better RFS (p = 0.014) than those treated exclusively by surgery. The patients in the IG-IMRT group exhibited better recurrence-free survival (p = 0.01) than the GKS group. Moreover, in the IG-IMRT group, patients treated by higher dose were associated with better RFS (p = 0.04). No significant difference in OS was found. No grade 3 late toxicity was found.

Conclusions

We confirmed that adjuvant radiotherapy improved RFS but not OS in sacral chordoma patients after surgery. Furthermore, favorable RFS and low adverse event rates were observed following IG-IMRT. Our results suggest that high dose IG-IMRT is an appropriate module of adjuvant radiotherapy for sacral chordoma patients.

Management of Sacrococcygeal Chordoma: A Systematic Review and Meta-analysis of Observational Studies

STUDY DESIGN

Systematic review and meta-analysis of observational studies.

OBJECTIVE

The aim of the study is to evaluate different treatment modalities in the management of sacrococcygeal chordoma.

SUMMARY OF BACKGROUND DATA

Chordomas are primary malignant bone tumors associated with considerable morbidity and mortality.

METHODS

We searched MEDLINE, EMBASE, Cochrane Central-Register of Controlled Trials, and Scopus from inception to July 2015. Eligible studies included patients with sacrococcygeal chordoma treated exclusively with surgery, radiotherapy, or both. Two reviewers independently assessed the eligibility of potential studies, risk of bias, and extracted data. Outcomes of interest were all-cause mortality, progression-free survival, and metastases. We analyzed further surgical outcomes by resection margin. All outcomes were assessed at 60 months and more than 60 months following intervention.

RESULTS

We included 33 noncomparative studies reporting on 501 patients (mean age 57 years). Overall mortality rate was (16%) after surgical resection with adjuvant radiotherapy and (28%) after surgical resection, and (43%) after radiotherapy (P = 0.28). All-cause mortality following wide surgical resection was (32%) compared to (40%) after marginal resection (P = 0.51). Overall progression-free survival rate was (58%) after surgical resection with adjuvant radiotherapy and (55%) after surgery (P = 0.92). However, at more than 60 months follow-up, progression-free survival rates were significantly higher (P = 0.024) following surgical resection with adjuvant radiotherapy (74%) in comparison to surgery (55%) and radiotherapy (36%). Overall progression-free survival rates were nonsignificantly higher after wide surgical resection (66%) than marginal resection (33%) (P = 0.16). However, at 60 months follow-up, progression-free survival rates were significantly higher following wide surgical resection (73%) than marginal resection (33%) (P = 0.047).

CONCLUSION

Sacrococcygeal chordoma is a difficult to treat disease entity. Until comparative studies become available, wide surgical resection and multidisciplinary management are the recommended approaches to improve patient outcomes.

LEVEL OF EVIDENCE

3.

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

BACKGROUND AND AIMS

The aim of this systematic review is to describe the epidemiology of chordoma and to provide a clear overview of clinical prognostic factors predicting progression-free and overall survival.

METHODS

Four databases of medical literature were searched. Separate searches were performed for each of the two objectives. Reference and citation tracking was performed. Papers were processed by two independent reviewers according to a protocol that included risk of bias analysis. Disagreement was resolved by discussion. Pooled analyses were planned if homogeneity of data would allow.

RESULTS

Incidence-incidence rates ranged between 0.18 and 0.84 per million persons per year and varied between countries and presumably between races. On average patients were diagnosed in their late fifties and gender data indicate clear male predominance. Two of the largest studies (n = 400 and n = 544) reported different anatomical distributions: one reporting the skull base and sacrococcygeal area affected in 32% and 29% of cases, whereas the other reporting that they were affected in 26% and 45% of cases, respectively.

PROGNOSTIC FACTORS

Statistically significant adverse prognostic factors predicting progression-free and overall survival include female sex, older age, bigger tumour size, increasing extent of tumour invasion, non-total resection, presence of metastasis, local recurrence, and dedifferentiated histological subtype.

CONCLUSIONS

Incidence rate and anatomical distribution vary between countries and presumably between races. Most chordomas arise in the skull base and sacrococcygeal spine, and the tumour shows clear male predominance. Multiple adverse prognostic factors predicting progression-free and overall survival were identified in subgroups of patients. These slides can be retrieved under Electronic Supplementary Material.

Role of the Apparent Diffusion Coefficient as a Predictor of Tumor Progression in Patients with Chordoma

BACKGROUND AND PURPOSE

Diffusion-weighted imaging may aid in distinguishing aggressive chordoma from nonaggressive chordoma. This study explores the prognostic role of the apparent diffusion coefficient in chordomas.

MATERIALS AND METHODS

Sixteen patients with residual or recurrent chordoma were divided postoperatively into those with an aggressive tumor, defined as a growing tumor having a doubling time of <1 year, and those with a nonaggressive tumor on follow-up MR images. The ability of the ADC to predict an aggressive tumor phenotype was investigated by receiver operating characteristic analysis. The prognostic role of ADC was assessed using a Kaplan-Meier curve with a log-rank test.

RESULTS

Seven patients died during a median follow-up of 48 months (range, 4-126 months). Five of these 7 patients were in the aggressive tumor group, and 2 were in the nonaggressive tumor group. The mean ADC was significantly lower in the aggressive tumor group than in the nonaggressive tumor group (P = .002). Receiver operating characteristic analysis showed that a cutoff ADC value of 1.494 × 10^-3 × mm²/s could be used to diagnose aggressive tumors with an area under the curve of 0.983 (95% CI, 0.911-1.000), a sensitivity of 1.000 (95% CI, 0.541-1.000), and a specificity of 0.900 (95% CI, 0.555-0.998). Furthermore, a cutoff ADC of ≤1.494 × 10^-3 × mm²/s was associated with a significantly worse prognosis (P = .006).

CONCLUSIONS

Lower ADC values could predict tumor progression in postoperative chordomas.

Variables affecting functional improvement in chordoma patients admitted to an inpatient rehabilitation facility: A retrospective review

STUDY DESIGN

Retrospective chart review of patients after surgical resection of chordoma admitted to an inpatient rehabilitation facility.

OBJECTIVE

To evaluate the characteristics associated with improving two or more functional levels and therefore classifying as a substantial responder after an inpatient rehabilitation facility stay in post-resection chordoma patients.

SETTING

Acute inpatient rehabilitation facility in the United States.

METHODS

A total of 40 patients were admitted to an inpatient rehabilitation facility from 2010-2015 after chordoma resection. Demographics, tumor management information, lengths of stay and functional independence measures on admission and discharge were collected. Substantial responders were identified as individuals who improved two or more functional levels based on total FIM score change. Logistic regression was used to analyze the available data for association of quantitative and categorical variables with being a substantial responder.

RESULTS

The categorical variables analyzed in this study (sex, readmission to an acute hospital, Charlson Comorbidity Index, tumor level, nerve sacrifice, recurrent tumor and metatases) were not associated with being a substantial responder. The quantitative variables age and length of stay at the inpatient rehabilitation facility were individually associated with being a substantial responder, while length of stay at the acute hospital was not.

CONCLUSIONS

Patients who were younger were more likely to be classified as substantial responders. Patients with longer lengths of stay at the inpatient rehabilitation facility were also more likely to be classified as substantial responders.

Analysis of prognostic factors for survival in patients with primary spinal chordoma using the SEER Registry from 1973 to 2014

BACKGROUND

Spinal chordomas are rare primary osseous tumors that arise from the remnants of the notochord. They are commonly considered slow-growing, locally invasive neoplasms with little tendency to metastasize, but the high recurrent rate of spinal chordomas may seriously affect the survival rate and quality of life of patients. The aim of the study is to describe the epidemiological data and determine the prognostic factors for decreased survival in patients with primary spinal chordoma.

METHODS

The Surveillance, Epidemiology, and End Results (SEER) Registry database, a US population-based cancer registry database, was used to identify all patients diagnosed with primary spinal chordoma from 1973 to 2014. We utilized Kaplan-Meier method and Cox proportional hazards regression analysis to evaluate the association between patients overall survival and relevant characteristics, including age, gender, race, disease stage, treatment methods, primary tumor site, marital status, and urban county background.

RESULTS

In the data set between 1973 and 2014, a total of 808 patients were identified with primary spinal chordoma. The overall rate of distant metastatic cases in our cohort was only 7.7%. Spinal chordoma was more common occurred in men (62.6%) than women (37.3%). Majority of neoplasms were found in the White (87.9%), while the incidence of the Black is relatively infrequent (3.3%). Three hundred fifty-seven spinal chordomas (44.2%) were located in the vertebral column, while 451 patients' tumor (55.8%) was located in the sacrum or pelvis. Age ≥ 60 years (HR = 2.72; 95%CI, 1.71 to 2.89), distant metastasis (HR = 2.16; 95%CI, 1.54 to 3.02), and non-surgical therapy (HR = 2.14; 95%CI, 1.72 to 2.69) were independent risk factors for survival reduction in analysis. Survival did not significantly differ as a factor of tumor site (vertebrae vs sacrum/pelvis) for primary spinal chordoma (HR = 0.93, P = 0.16). Race (P = 0.52), gender (P = 0.11), marital status (P = 0.94), and urban background (P = 0.72) were not main factors which affected overall survival rate.

CONCLUSION

There was no significant difference in overall survival rate between chordomas located in the sacrum and vertebral column. Spinal chordoma patients with an elderly age (age ≥ 60), performing non-surgical therapy, and distant metastasis were associated with worse overall survival. Performing surgery was an effective and reliable treatment method for patients with spinal chordoma, and public health efforts should pay more attention to the elderly patients with spinal chordoma prior to distant metastasis.

Prognostic Factors and Survival Outcome in Patients with Chordoma in the United States: A Population-Based Analysis

OBJECTIVE

To evaluate prognostic factors of patients with chordoma through a population-based analysis.

METHODS

Surveillance, Epidemiology, and End Results (SEER) database was queried for patients with chordoma from 1973 to 2013. Kaplan-Meier univariate analysis and Cox regression multivariate analysis were performed to examine prognostic factors in overall survival (OS) and disease-specific survival (DSS).

RESULTS

One thousand five hundred ninety-eight patients with chordoma are identified. Kaplan-Meier analysis showed that OS and DSS were 61% and 71% at 5 years and 41% and 57% at 10 years. Multivariate Cox regression analysis demonstrated that independent predictors of OS and DSS are age at diagnosis (hazard ratio [HR]= 2.80 [95% confidence interval {CI}, 2.12-3.70], P < 0.001; HR = 1.60 [95% CI, 1.18-2.16], P = 0.002), surgical treatment (HR = 0.62 [95% CI, 0.52-0.73], P < 0.001; HR = 0.64 [95% CI, 0.52-0.79], P < 0.001), radiation therapy (HR = 1.23 [95% CI, 1.07-1.42], P = 0.004; HR = 1.29 [95% CI, 1.09-1.54], P = 0.004), tumor size (HR = 1.53 [95% CI, 1.32-1.78], P < 0.001; HR = 1.62 [95% CI, 1.35-1.94], P < 0.001) and distant metastasis (HR = 3.40 [95% CI, 2.45-4.71], P < 0.001; HR = 3.77 [95% CI, 2.61-5.45], P < 0.001).

CONCLUSION

We report the largest study to date to evaluate prognostic factors of patients with chordoma. Multivariate analysis demonstrated that older age, greater tumor size, and distant metastasis were correlated with decreased survival, whereas surgical resection was correlated with increased survival. Patients receiving radiation therapy also showed decreased survival, likely an indication of the patients' advanced stage of disease, making them poor surgical candidates.

Computer Navigation-aided Resection of Sacral Chordomas

BACKGROUND

Resection of sacral chordomas is challenging. The anatomy is complex, and there are often no bony landmarks to guide the resection. Achieving adequate surgical margins is, therefore, difficult, and the recurrence rate is high. Use of computer navigation may allow optimal preoperative planning and improve precision in tumor resection. The purpose of this study was to evaluate the safety and feasibility of computer navigation-aided resection of sacral chordomas.

METHODS

Between 2007 and 2013, a total of 26 patients with sacral chordoma underwent computer navigation-aided surgery were included and followed for a minimum of 18 months. There were 21 primary cases and 5 recurrent cases, with a mean age of 55.8 years old (range: 35-84 years old). Tumors were located above the level of the S3 neural foramen in 23 patients and below the level of the S3 neural foramen in 3 patients. Three-dimensional images were reconstructed with a computed tomography-based navigation system combined with the magnetic resonance images using the navigation software. Tumors were resected via a posterior approach assisted by the computer navigation. Mean follow-up was 38.6 months (range: 18-84 months).

RESULTS

Mean operative time was 307 min. Mean intraoperative blood loss was 3065 ml. For computer navigation, the mean registration deviation during surgery was 1.7 mm. There were 18 wide resections, 4 marginal resections, and 4 intralesional resections. All patients were alive at the final follow-up, with 2 (7.7%) exhibiting tumor recurrence. The other 24 patients were tumor-free. The mean Musculoskeletal Tumor Society Score was 27.3 (range: 19-30).

CONCLUSIONS

Computer-assisted navigation can be safely applied to the resection of the sacral chordomas, allowing execution of preoperative plans, and achieving good oncological outcomes. Nevertheless, this needs to be accomplished by surgeons with adequate experience and skill.

PARP1 is a novel independent prognostic factor for the poor prognosis of chordoma

OBJECTIVE

To evaluate the expression of PARP1 in chordoma and analyzed its association with clinical factors and patients' prognosis.

METHODS

The expression of Poly (ADP-ribose) polymerase 1 (PARP1) in chordoma specimens from 74 chordoma patients (50 primary and 24 recurrent tumors of 50 patients)and 20 distant normal tissue specimens was measured by immunohistochemical staining. The association of PARP1with the clinical factors and patients' prognosis was also analyzed.

RESULTS

Of all the chordoma samples, 78% showed high expression of PARP1, whereas, only 10% of distant normal tissues expressed a high level of PARP1 (p< 0.01). Chi-square analysis revealed that high expression of PARP1 was significantly correlated with tumor recurrence (p< 0.01) and invasion into surrounding muscle (p< 0.01), while the data did not indicate any association with patients' gender, age, tumor location and size (p> 0.05). Kaplan-Meier survival curve and log-rank test showed that continuous disease free survival time (CDFS) was significantly shorter in the PARP1-positive group than in the PARP1-negative group (P= 0.019).

CONCLUSION

High expression of PARP1 is significantly associated with chordoma invasion and recurrence. PARP1 may become a potential biomarker for chordoma in predicting its recurrence and patients' prognosis.

Safety and Local Control of Radiation Therapy for Chordoma of the Spine and Sacrum: A Systematic Review

STUDY DESIGN

Systematic literature review.

OBJECTIVE

To assess the toxicity, common radiation doses, and local control (LC) rates of radiation therapy for chordoma of the spine and sacrum and identify the difference in LC and toxicity between adjuvant, salvage, and primary therapy using radiation.

SUMMARY OF BACKGROUND DATA

Chordoma of the spine is typically a low-grade malignant tumor thought to be relatively radioresistant with a high rate of local recurrence and the potential for metastases. Improved results of modern radiation therapy in the treatment of chordoma support exploration of its role in the management of primary/de novo chordoma or recurrent chordoma.

METHODS

We conducted a systematic literature review using PubMed and Embase databases to assess information available regarding the toxicity, LC rates, and overall survival (OS) rates for adjuvant, salvage, and primary radiation therapy for spinal and sacral chordoma.

RESULTS

A total of 40 articles were reviewed. Evidence quality was low or very low. The highest rates of LC and OS were with early adjuvant RT for primary/de novo disease. Salvage RT for recurrent disease has very small cohorts and thus strong conclusions were not able be made.

CONCLUSION

The use of pre- and/or post-operative photon image-guided radiotherapy (IGRT), proton or carbon ion therapy should be considered for patients undergoing surgery for the treatment of primary and recurrent chordomas in the mobile spine and sacrum, since these RT modalities may improve local control. Preoperative evaluation by the surgeon and radiation oncologist should be used to formulate a cohesive treatment plan.The use of photon IGRT or carbon ion therapy as the primary treatment of chordoma, when currently in its developmental stage, shows promise and requires clear delineation of toxicity profile and long-term local control.

LEVEL OF EVIDENCE

2.

Surgical spacer placement prior carbon ion radiotherapy (CIRT): an effective feasible strategy to improve the treatment for sacral chordoma

Background

Sacral chordoma (SC) is a neoplasm arising from residual notochordal cells degeneration. SC is difficult to manage mainly because of anatomic location and tendency to extensive spread. Carbon ion radiotherapy (CIRT) is highly precise to selectively deliver high biological effective dose to the tumor target sparing the anatomical structure on its path even if when SC is contiguous to the intestine, and a surgical spacer might be an advantageous tool to create a distance around the target volume allowing radical curative dose delivery with a safe dose gradient to the surrounding organs. This paper describes a double approach—open and hand-assisted laparoscopic—for a silicon spacer placement in patients affected by sacral chordoma undergoing carbon ion radiotherapy.

Methods

Six consecutive patients have been enrolled for surgical spacer placement—open (three) or hand-assisted (three)—prior carbon ion radiotherapy treatment in order to increase efficacy of carbon ion radiotherapy minimizing its side effects.

Results

Results showed that silicon spacer placement for SC treatment is feasible both via laparoscopic and laparotomic approach.

Conclusions

Its use might improve CIRT safety and thus efficacy for SC treatment.

Sacral Chordoma: Long-term Outcome of a Large Series of Patients Surgically Treated at Two Reference Centers

STUDY DESIGN

Retrospective case series.

OBJECTIVE

To report on the natural history and long-term outcome of a large series of consecutive primary sacral chordoma patients surgically treated at two reference centers.

SUMMARY OF BACKGROUND DATA

Sacral chordomas are rare tumors with poor long-term prognosis mainly caused by local failure. Till date, a few large series with long follow up are available in literature.

METHODS

All consecutive patients affected by primary localized sacral chordoma operated on at two Italian reference centers between 1981 and 2012 were included. Overall survival (OS), disease free survival (DFS), crude cumulative incidence (CCI) of local recurrence (LR), and distant metastases (DM) were calculated. Multivariable analyses for OS, DFS, LR, and DM were performed.

RESULTS

A total of 99 patients were identified: 65 males and 34 females. Median age was 59 years (range 22-77 yrs), median tumor size was 9 cm (range 4-22). Nineteen patients received pre- or postoperative radiotherapy (RT). Wide (R0) surgical margins were achieved in 46 patients, marginal (R1) margins in 43 patients and intralesional (R2) margins in 10 patients. At a median follow up of 8.7 years (range 1-23.8 yrs) 30 patients died of disease, 31 patients developed local relapse, 16 patients developed distant metastasis, whereas 51 patients are alive without disease. OS and DFS at 5, 10, and 15 year were 92% and 63%, 45% and 62%, 36% and 21%, respectively, without any evidence of a plateau in the curves.CCI of LR and DM were 30% and 9% at 5 years, 46% and 18% at 10 years, 56% and 23% at 15 years. Size of the tumor and quality of surgical margins were the only significant predictors of long-term outcome. DFS for 15 years was, in fact, 49% for R0 and 7% for R1, respectively.

CONCLUSION

In this series, long-term outcome of resected sacral chordoma was poor, with less than 25% patients were disease-free at 15 years. Interestingly, only half of the patients treated with R0 resection had no evidence of recurrence at 15 years. When surgical margins are expected to be positive other treatment modalities should be considered, especially when expected sequelae are substantial as in the case of more cephalad levels of resection.

LEVEL OF EVIDENCE

3.

C-reactive protein as a prognostic factor in patients with chordoma of lumbar spine and sacrum--a single center pilot study

Study design

This is a retrospective, diagnostic study, level IV.

Background

It appears to be necessary to identify prognostic markers for individual risk estimation for progression and survival in patients with chordoma, a rare disease. Are pre-operative serum levels of C-reactive protein (CRP) associated with disease progression and survival?

Methods

Survival rates of 24 patients (18 males, 6 females) (mean age 67 years (SD ± 16; range 20–85 years); minimum follow-up 2 years, mean follow-up 5 years (SD ± 5; range 2–19 years)) with chordoma of the lower spine and sacrum were assessed with a focus on pre-operative CRP levels.

Results

The survival rate of patients with pre-operative CRP level of >1.0 mg/dl was lower than that of patients with a CRP level <1.0 mg/dl (p = 0.01). The estimated 10-year survival of patients with pre-operative CRP values <1.0 and >1.0 mg/dl was 76 and 25 %, respectively. CRP remained as an independent survival factor (p = 0.025; CI 95 % 1.0–2.6) in multivariable analysis.

Conclusions

Pre-operative CRP levels appear to be a biomarker for disease-specific survival in patients with chordoma of the lumbar spine and sacrum. A validation of our finding with larger cohorts and integration of putative risk factor would further elucidate CRP a surrogate for tumor progression.

Prognostic factors in spinal chordoma: A systematic review

OBJECTIVE

Discovering reliable prognostic factors for spinal chordoma remains a challenge. We attempted to identify evidence-based prognostic factors in the literature since its inception and to establish pooled relative risks (RR) of such factors.

METHODS

MEDLINE and Embase search (inception to December 2014). Two reviewers independently selected papers involving spinal chordoma prognostic factors, and studied them for methodological quality and valuable new factors. Subsequently, we attempted to pool the results.

RESULTS

Of 1465 citations, we studied 65 papers closely, and found several "new" prognostic factors. However, only eight papers were of adequate quality for analysis. Location in the upper cervical spine (pooled RR=5.46, 95% confidence interval [CI]: 2.23-13.34), worse preoperative Frankel score (pooled RR=2.77, 95% CI: 1.73-4.42), intralesional surgery (pooled RR=2.68, 95% CI: 1.66-4.32), greater extent of invasion (pooled RR=5.09, 95% CI: 1.49-17.41), and revision surgery (pooled RR=2.42, 95% CI: 1.34-4.36) appeared to be independent factors for worse outcome.

CONCLUSIONS

Despite the wealth of literature available, disappointingly few papers are of sufficient quality for drawing valid conclusions related to spinal chordoma prognostic factors. The heterogeneity of the studies renders results pooling almost impossible. More accurate individual prognostication requires methodologically high-quality studies with more uniform study design and data reporting.

Prognostic Factors in the Operative Management of Sacral Chordomas

OBJECTIVE

Surgical resection of sacral chordomas offers the best long-term prognosis but has high rates of local recurrence, metastases, and mortality. Most prognostic studies are limited by low patient numbers, variation in treatment, follow-up, and prognostic variables studied. The objective of this study was to identify factors associated with recurrence, metastasis, and survival.

METHODS

Retrospective review of 58 patients undergoing sacrectomy for chordoma with a mean age of 63 years (range: 41-80 years) and a mean follow-up of 45.3 months (range: 2-144 months). Data on prognostic variables and outcomes were collected. Forty-two patients underwent a combined anterior and posterior approach and 16 underwent a posterior-only approach.

RESULTS

Twenty-six patients (44.8%) died during follow-up. Kaplan-Meier estimates for 5- and 10-year survival were 62% and 26%, respectively. Local recurrence occurred in 32 patients (51.7%) and metastases in 19 (32.7%). Adequacy of resection margins was the most important predictor of disease recurrence, metastases, and survival. Tumors >8 cm were associated with significantly increased risk of metastases and reduced survival (P < 0.05). Dedifferentiated disease and infiltration of the sacroiliac joints and/or adjacent musculature were also associated with reduced survival. Median survival was 23 months for patients with gluteus maximus invasion, 66 months for gluteus maximus and piriformis invasion, 67 months for piriformis invasion, and 90 months for patients with no muscle invasion.

CONCLUSIONS

Patients with inadequate resection margins, tumors >8 cm, sacroiliac joint and/or musculature infiltration, and dedifferentiated disease have significantly worse oncologic outcomes. Involvement of gluteus maximus alone confers a higher risk of metastases and local recurrence than involvement of piriformis and gluteus maximus, or piriformis alone.

Carbon ion beam treatment in patients with primary and recurrent sacrococcygeal chordoma

PURPOSE

The purpose of this work was to evaluate the results of high-dose radiation treatment using carbon ion therapy, alone or combined with intensity-modulated radiation treatment (IMRT), in patients with sacral chordoma.

MATERIALS AND METHODS

Between 2009 and 2012, 56 patients with sacral chordoma were treated in our center. The tumor was located above S3 in 33 patients and in S3 or below in 23 patients. In all, 41 patients received radiation therapy for the primary tumor, while 15 patients were treated for the recurrent tumor. Toxicity was measured using NCI CTCAE v.4.03. Local control (LC) and overall survival (OS) were evaluated with the Kaplan-Meier method.

RESULTS

A total of 23 patients were irradiated with carbon ions in combination with photon IMRT, while 33 received carbon ion therapy only. Forty-three patients had a macroscopic tumor at treatment start with a median tumor size (GTV) of 244 ml (range 5-1188 ml). The median total dose was 66 Gy (range 60-74 Gy; RBE). After a median follow-up time of 25 months, the 2- and 3-year local control probability was 76 % and 53 %, respectively. The overall survival rate was 100 %. Treatment for primary tumor and male patients resulted in significant better local control. No higher toxicity occurred within the follow-up time.

CONCLUSION

High-dose photon/carbon ion beam radiation therapy is safe and, especially for primary sacral chordomas, highly effective. A randomized trial is required to evaluate the role of primary definitive hypofractionated particle therapy compared with surgery with or without adjuvant radiotherapy.

Maintenance of bowel, bladder, and motor functions after sacrectomy

BACKGROUND CONTEXT

Repeated cohort studies have consistently demonstrated a survival advantage after en bloc resection for locally aggressive primary tumors in the sacrum. A sacrectomy is often required to remove the tumor en bloc, which may necessitate the sacrifice of sacral nerves. This can potentially result in functional complications, including the impairment of gait, bowel function, or bladder function.

PURPOSE

To assess the bladder, bowel, and motor functions of patients after resection of a primary sacral tumor.

STUDY DESIGN

This was a retrospective cohort study at a single academic institution.

PATIENT SAMPLE

Consecutive patients who underwent an en bloc sacral tumor resection at a single institution between December 2002 and June 2012 were included. The study population comprised 73 patients.

OUTCOME MEASURES

Patients were classified as having had a low, middle, high, or total sacrectomy based on the level of sacral nerves sacrificed, if applicable.

METHODS

Patient data were collected from clinic notes and hospital records that included operative notes, lab studies, and rehabilitation notes.

RESULTS

Across all patients, there was no change in bowel function after sacrectomy, whereas bladder and motor functions returned to preoperative (pre-op) levels at 3 and 6 months, respectively. Higher level sacrectomies were associated with worse bowel (p<.001), bladder (p<.001), and motor (p=.027) functions 12 months postoperatively (post-op). At 1 year, none of the six patients with a high or total sacrectomy had intact bladder function and 14.3% (N=7) had intact bowel function. Of patients with a middle sacrectomy, 62.5% (N=8) had intact bladder function and 71.4% (N=7) had intact bowel function at 1 year. Of patients with a low sacrectomy, 91.7% (N=12) had intact bladder function and 91.7% (N=12) had intact bowel function.

CONCLUSIONS

Preoperative bladder, bowel, and motor functions, level of sacral tumor involvement, and corresponding level of sacrectomy were the greatest predictors of long-term bladder, bowel, and motor functions. There were no statistically significant changes in bladder, bowel, or motor functions from pre-op to 6 months post-op, and therefore, pre-op functional status was predictive of long-term function.