Surgical treatment of sacral chordoma: prognostic variables for local recurrence and overall survival

Clinical characteristics and predisposing factors of lung metastasis in sacral chordoma: a cross-sectional cohort study of 221 cases

Introduction

Limited studies are available on the topic of lung metastasis in sacral chordoma. The primary objective of this study was to investigate the prevalence, characteristics, associated factors, and prognosis of lung metastasis in sacral chordoma.

Methods

A total of 221 cases with primary sacral chordoma, all of whom underwent surgical resection at our center, were included in this study. Comprehensive demographic information, imaging findings, and oncological evaluations were collected and thoroughly analyzed. The diagnosis of lung metastasis in the majority of cases was established through radiographic examinations.

Results

The prevalence of lung metastasis in the cohort was 19.5%, with the lung emerging as the predominant site of distant metastasis. Recurrent chordoma cases exhibited a significantly higher lung metastasis rate in comparison to newly diagnosed chordoma cases (33.33% and 12.76%, p=0.0005). Patients with lung metastasis had a larger tumor size, a higher proportion of previous sacral chordoma surgeries and a greater likelihood of postoperative recurrence. Associated factors of lung metastasis were tumor size, postoperative recurrence and radiotherapy. Patients with lung metastasis exhibited decreased median overall survival (91 vs. 144 months for those without lung metastasis, p<0.05) and recurrence-free survival (27 vs. 68 months, p<0.001) times.

Discussion

Lung is the most common site of distant metastasis in sacral chordoma with an incidence rate nearly 20%. Larger tumor size and postoperative recurrence are risk factors for lung metastasis while radiotherapy is a protective factor. Occurrence of lung metastasis in sacral chordoma is a negative prognostic factor.

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.

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.

The Role of En Bloc Resection in the Modern Era for Primary Spine Tumors

STUDY DESIGN

A literature review.

OBJECTIVE

The aim of this review is to provide an overview of benign and malignant primary spine tumors and a balanced analysis of the benefits and limitations of (and alternatives to) surgical treatment with en bloc resection.

SUMMARY OF BACKGROUND DATA

Primary spine tumors are rare but have the potential to cause severe morbidity, either from the disease itself or as a result of treatment. The prognosis, goals, and treatment options vary significantly with the specific disease entity. Appropriate initial management is critical; inappropriate surgery before definitive treatment can lead to recurrence and may render the patient incurable, as salvage options are often inferior.

METHODS

We performed a comprehensive search of the PubMed database for articles relevant to primary spine neoplasms and en bloc spine surgery. Institutional review board approval was not needed.

RESULTS

Although Enneking-appropriate en bloc surgery can be highly morbid, it often provides the greatest chance for local control and/or patient survival. However, there is growing data to support modern radiotherapy as a feasible and less morbid approach to certain primary neoplasms that historically were considered radioresistant.

CONCLUSIONS

Choosing the optimal approach to primary spine tumors is complex. A comprehensive and up-to-date assessment of the evidence is required to guide patient care and to balance the often-competing goals of prolonging life and preserving quality of life.

Deep-Learning-Based Model for the Prediction of Cancer-Specific Survival in Patients with Spinal Chordoma

OBJECTIVE

Spinal chordomas are locally aggressive and frequently recurrent tumors with a poor prognosis. Previous studies focused on a Cox regression model to predict the survival of patients with spinal chordoma. We aimed to develop a more effective model based on deep learning for prognosis prediction in spinal chordoma.

METHODS

Patients with spinal chordoma were gathered from the SEER database. Cox regression analysis was conducted to compare the influence of different clinical characteristics on cancer-specific survival. Two deep learning models, namely, DeepSurv and NMTLR, were developed, alongside 2 classic models, for the purpose of comparison. Performance of these models was evaluated by concordance index, Integrated Brier Score, receiver operating characteristic curves, Kaplan-Meier curves, and calibration curves.

RESULTS

A total of 258 spinal chordoma patients were included in the current study. The median follow-up time was 94 ± 52 months. Variables used for prognosis prediction consisted of age, primary site, tumor size, histologic grade, extension of surgery, tumor invasion, and metastasis. Comparing with conventional models, each deep learning model showed superior predictive performance, the C-index on the test cohort is 0.830 for DeepSurv and 0.804 for NMTLR, respectively. The DeepSurv model represented the best performance, with area under the curve of 0.843 in predicting 5-year survival and 0.880 in predicting 10-year survival.

CONCLUSIONS

We successfully constructed a deep learning model to predict the CSS of spinal chordoma patients and proved that it was more accurate and practical than conventional prediction model. Our deep learning model has the potential to guide clinicians in better care planning and decision-making.

Long-Term Outcomes after Multimodal Treatment for Clival Chordoma: Efficacy of the Endonasal Transclival Approach with Early Adjuvant Radiation Therapy

This study investigates the long-term outcomes of clival chordoma patients treated with the endonasal transclival approach (ETCA) and early adjuvant radiation therapy. A retrospective review of 17 patients (2002-2013) showed a 10-year progression-free survival (PFS) rate of 67.4%, with the ETCA group showing fewer progressions and cranial neuropathies than those treated with combined approaches. The ETCA, a minimally invasive technique, provided a similar extent of resection compared to conventional skull-base approaches and enabled safe delivery of high-dose adjuvant radiotherapy. The findings suggest that ETCA is an effective treatment for centrally located clival chordomas.

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.

Immunotherapy as a Promising Option for the Treatment of Advanced Chordoma: A Systemic Review

OBJECTIVE

To summarize the function and efficacy of immunotherapy as an adjunctive therapy in the treatment of advanced chordoma.

METHODS

Literature search was conducted by two reviewers independently. Case reports, case series and clinical trials of immunotherapy for chordoma were retrieved systematically from Pubmed, Web of Science, Scoupus and Cochrane Library. Clinical outcome data extracted from the literature included median progression-free survival (PFS), median overall survival (OS), clinical responses and adverse events (AEs).

RESULTS

All studies were published between 2015 and 2022. Twenty-two eligible studies were selected for systemic review. PD-1/PD-L1 immune checkpoint inhibitors (ICIs) were the most common used immunotherapy agents in chordoma, among which Pembrolizumab was the most frequently prescribed. CTLA-4 antibody was only used as combination therapy in chordoma. Dose Limiting Toxicity (DLT) was not observed in any vaccine targeting brachyury, and injection site response was the most frequent AV. The response evaluation criteria in solid tumors (RECIST) were the most generally used evaluation standard in chordoma immunotherapy, and none of the included studies employed the Choi criteria.

CONCLUSIONS

No clinical data have demonstrated that CTLA-4 ICIs combined with PD-1/PD-L1 ICIs is more effective than ICIs monotherapy in treating chordoma, and ICIs in combination with other therapies exhibit more toxicity than monotherapy. PD-1/PD-L1 ICIs monotherapy is recommended as an immunotherapy in patients with advanced chordoma, which may even benefit PD-L1-negative patients. The brachyury vaccine has shown good safety in chordoma patients, and future clinical trials should focus on how to improve its therapeutic efficacy. The use of immunomodulatory agents is a promising therapeutic option, though additional clinical trials are required to evaluate their safety and effectiveness. RECIST does not seem to be an appropriate standard for assessing medications of intratumoral immunotherapy.

The management of sacral tumours

Tumours of the sacrum are difficult to manage. The sacrum provides the structural connection between the torso and lower half of the body and is subject to both axial and rotational forces. Thus, tumours or their treatment can compromise the stability of the spinopelvic junction. Additionally, nerves responsible for lower limb motor groups as well as bowel, bladder, and sexual function traverse or abut the sacrum. Preservation or sacrifice of these nerves in the treatment of sacral tumours has profound implications on the function and quality of life of the patient. This annotation will discuss current treatment protocols for sacral tumours.

Cite this article: Bone Joint J 2022;104-B(12):1284–1291.

Circumferential sulcus-guided resection technique for improved outcomes of low-grade gliomas

OBJECTIVE

Many neurosurgeons resect nonenhancing low-grade gliomas (LGGs) by using an inside-out piecemeal resection (PMR) technique. At the authors' institution they have increasingly used a circumferential, perilesional, sulcus-guided resection (SGR) technique. This technique has not been well described and there are limited data on its effectiveness. The authors describe the SGR technique and assess the extent to which SGR correlates with extent of resection and neurological outcome.

METHODS

The authors identified all patients with newly diagnosed LGGs who underwent resection at their institution over a 22-year period. Demographics, presenting symptoms, intraoperative data, method of resection (SGR or PMR), volumetric imaging data, and postoperative outcomes were obtained. Univariate analyses used ANOVA and Fisher's exact test. Multivariate analyses were performed using multivariate logistic regression.

RESULTS

Newly diagnosed LGGs were resected in 519 patients, 208 (40%) using an SGR technique and 311 (60%) using a PMR technique. The median extent of resection in the SGR group was 84%, compared with 77% in the PMR group (p = 0.019). In multivariate analysis, SGR was independently associated with a higher rate of complete (100%) resection (27% vs 18%) (OR 1.7, 95% CI 1.1-2.6; p = 0.03). SGR was also associated with a statistical trend toward lower rates of postoperative neurological complications (11% vs 16%, p = 0.09). A subset analysis of tumors located specifically in eloquent brain demonstrated SGR to be as safe as PMR.

CONCLUSIONS

The authors describe the SGR technique used to resect LGGs and show that SGR is independently associated with statistically significantly higher rates of complete resection, without an increase in neurological complications, than with PMR. SGR technique should be considered when resecting LGGs.

Immune Checkpoint Inhibitors Have Clinical Activity in Patients With Recurrent Chordoma

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

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

Background

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

Methods

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

Results

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

Conclusions

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

Weekly cisplatin with or without imatinib in advanced chordoma: A retrospective case-series analysis from the Italian Rare Cancers Network

BACKGROUND

To report on a retrospective case-series analysis of weekly cisplatin (wCDDP) as a single agent or combined with imatinib (wCDDP/I) in patients with advanced chordoma treated within the Italian Rare Cancer Network.

METHODS

Adult patients with a diagnosis of advanced, brachyury-positive chordoma, treated from April 2007 to October 2020 with wCDDP or wCDDP/I were retrospectively identified. Imatinib was withheld at the same time as wCDDP. Response according to Response Evaluation Criteria in Solid Tumors, overall survival (OS), and progression-free survival (PFS) were analyzed.

RESULTS

Thirty-three consecutive patients were identified (wCDDP as front-line n = 8 [24.2%]; wCDDP as a further line n = 25 [75.8%]; prior imatinib n = 25 [75.8%]; evidence of progression before starting wCDDP n = 33). Of 32 patients evaluable for response (wCDDP, n = 22 [68.8%]; wCDDP/I, n = 10 [31.3%]), best response was stable disease (SD) in 27 patients (84.3%) and progression in 5 patients (15.6%). At a median follow-up of 54 months, the median OS (m-OS) was 30.3 months (interquartile range [IQR], 18.1-56.6), the m-PFS was 8.0 months (IQR, 5.1-17.0), the 6-month PFS rate was 65.2%, and the 12-month PFS rate was 30.3%. Of 22 patients who received wCDDP, the best response was SD in 18 patients (81.8%) and progression in 4 patients (18.2%), and the m-PFS was 8.0 months (IQR, 5.1-17.0 months). Of 10 patients who received treatment with wCDDP/I, the best response was SD in 9 patients (90%) and progression in 1 patient (10%), and the m-PFS was 9.3 months (IQR, 4.9-26.5 months).

CONCLUSIONS

This series suggests that wCDDP, both as a single agent and combined with imatinib, has antitumor activity in chordoma. Although no dimensional responses were observed, 65% and 30% of previously progressive patients were progression-free at 6 and 12 months, respectively. A prospective study is warranted.

A Novel Three-Dimensional Computational Method to Assess Rod Contour Deformation and to Map Bony Fusion in a Lumbopelvic Reconstruction After En-Bloc Sacrectomy

Introduction: En-bloc resection of a primary malignant sacral tumor with wide oncological margins impacts the biomechanics of the spinopelvic complex, deteriorating postoperative function. The closed-loop technique (CLT) for spinopelvic fixation (SPF) uses a single U-shaped rod to restore the spinopelvic biomechanical integrity. The CLT method was designed to provide a non-rigid fixation, however this hypothesis has not been previously tested. Here, we establish a computational method to measure the deformation of the implant and characterize the bony fusion process based on the 6-year follow-up (FU) data.

Materials and Methods: Post-operative CT scans were collected of a male patient who underwent total sacrectomy at the age of 42 due to a chordoma. CLT was used to reconstruct the spinopelvic junction. We defined the 3D geometry of the implant construct. Using rigid registration algorithms, a common coordinate system was created for the CLT to measure and visualize the deformation of the construct during the FU. In order to demonstrate the cyclical loading of the construct, the patient underwent gait analysis at the 6th year FU. First, a region of interest (ROI) was selected at the proximal level of the construct, then the deformation was determined during the follow-up period. In order to investigate the fusion process, a single axial slice-based voxel finite element (FE) mesh was created. The Hounsfield values (HU) were determined, then using an empirical linear equation, bone mineral density (BMD) values were assigned for every mesh element, out of 10 color-coded categories (1st category = 0 g/cm³, 10th category 1.12 g/cm³).

Results: Significant correlation was found between the number of days postoperatively and deformation in the sagittal plane, resulting in a forward bending tendency of the construct. Volume distributions were determined and visualized over time for the different BMD categories and it was found that the total volume of the elements in the highest BMD category in the first postoperative CT was 0.04 cm³, at the 2nd year, FU was 0.98 cm³, and after 6 years, it was 2.30 cm³.

Conclusion: The CLT provides a non-rigid fixation. The quantification of implant deformation and bony fusion may help understate the complex lumbopelvic biomechanics after sacrectomy.

Outcomes of Surgery for Sacral Chordoma and Impact of Complications: A Report of 50 Consecutive Patients With Long-Term Follow-Up

STUDY DESIGN

Retrospective case series.

OBJECTIVE

To determine predictive factors of overall survival (OS) and local recurrence (LR), report complications, and assess the impact of complications on survival, recurrence, and function in patients undergoing en bloc resection of sacral chordoma.

METHODS

This retrospective case series was obtained from a prospective database (1995-2016). All patients underwent en bloc resection of sacral chordoma. Demographic, perioperative, and complication data were collected. Outcomes included: overall survival(OS), local recurrence(LR), and complications. Survival analysis with multivariable cox regression was performed.

RESULTS

Among 50 patients, median follow-up was 5.3 years (range = 1.3-17.2). The majority (82%) underwent a negative margin resection. Survival: 17 patients died (34%) with a median OS of 10.0 years (range = 1.3-17.2). Multivariable cox regression revealed that a negative margin resection was not significantly associated with improved survival (HR = 3.35, 95%CI 0.87-12.80, P = .078). Recurrence: 20 patients (40%) experienced LR with a median time of 6.2 years (range = 0-16.9). Multivariable cox regression revealed that a negative margin resection was associated with a significant decreased risk of LR (HR = 4.96, 95%CI 1.84-13.34, P = 0.002,). A 62% overall complication rate was seen (42% major), with 26% reoperation rate. Of the reoperations, 54% were delayed (>6 weeks after the index surgery). Multivariable cox regression demonstrated that neither major complication nor reoperation significantly impacted OS (HR = 0.62, 95%CI 0.22-1.79, P = 0.380), LR (HR = 1.28, 95%CI 0.49-3.36, P = 0.611), or functional outcomes (OR = 2.94, 95%CI 0.25-34.8, P = 0.393).

CONCLUSIONS

Negative margin resection was associated with decreased LR. Neither major complication nor reoperation significantly impacted OS, LR, or functional outcome. Though additional studies are needed, it appears that despite the morbidity associated with sacral chordoma resection, the long-term clinical outcomes are favorable.

Feasibility of achieving planned surgical margins in primary spine tumor: a PTRON study

OBJECTIVE

Oncological resection of primary spine tumors is associated with lower recurrence rates. However, even in the most experienced hands, the execution of a meticulously drafted plan sometimes fails. The objectives of this study were to determine how successful surgical teams are at achieving planned surgical margins and how successful surgeons are in intraoperatively assessing tumor margins. The secondary objective was to identify factors associated with successful execution of planned resection.

METHODS

The Primary Tumor Research and Outcomes Network (PTRON) is a multicenter international prospective registry for the management of primary tumors of the spine. Using this registry, the authors compared 1) the planned surgical margin and 2) the intraoperative assessment of the margin by the surgeon with the postoperative assessment of the margin by the pathologist. Univariate analysis was used to assess whether factors such as histology, size, location, previous radiotherapy, and revision surgery were associated with successful execution of the planned margins.

RESULTS

Three hundred patients were included. The surgical plan was successfully achieved in 224 (74.7%) patients. The surgeon correctly assessed the intraoperative margins, as reported in the final assessment by the pathologist, in 239 (79.7%) patients. On univariate analysis, no factor had a statistically significant influence on successful achievement of planned margins.

CONCLUSIONS

In high-volume cancer centers around the world, planned surgical margins can be achieved in approximately 75% of cases. The morbidity of the proposed intervention must be balanced with the expected success rate in order to optimize patient management and surgical decision-making.

Systematic review of charged-particle therapy for chordomas and sarcomas of the mobile spine and sacrum

OBJECTIVE

Long-term local control in patients with primary chordoma and sarcoma of the spine and sacrum is increasingly reliant upon en bloc resection with negative margins. At many institutions, adjuvant radiation is recommended; definitive radiation is also recommended for the treatment of unresectable tumors. Because of the high off-target radiation toxicities associated with conventional radiotherapy, there has been growing interest in the use of proton and heavy-ion therapies. The aim of this study was to systematically review the literature regarding these therapies.

METHODS

The PubMed, OVID, Embase, and Web of Science databases were queried for articles describing the use of proton, combined proton/photon, or heavy-ion therapies for adjuvant or definitive radiotherapy in patients with primary sarcoma or chordoma of the mobile spine and sacrum. A qualitative synthesis of the results was performed, focusing on overall survival (OS), progression-free survival (PFS), disease-free survival (DFS), and disease-specific survival (DSS); local control; and postradiation toxicities.

RESULTS

Of 595 unique articles, 64 underwent full-text screening and 38 were included in the final synthesis. All studies were level III or IV evidence with a high risk of bias; there was also significant overlap in the reported populations, with six centers accounting for roughly three-fourths of all reports. Five-year therapy outcomes were as follows: proton-only therapies, OS 67%-82%, PFS 31%-57%, and DFS 52%-62%; metastases occurred in 17%-18% and acute toxicities in 3%-100% of cases; combined proton/photon therapy, local control 62%-85%, OS 78%-87%, PFS 90%, and DFS 61%-72%; metastases occurred in 12%-14% and acute toxicities in 84%-100% of cases; and carbon ion therapy, local control 53%-100%, OS 52%-86%, PFS (only reported for 3 years) 48%-76%, and DFS 50%-53%; metastases occurred in 2%-39% and acute toxicities in 26%-48%. There were no studies directly comparing outcomes between photon and charged-particle therapies or comparing outcomes between radiation and surgical groups.

CONCLUSIONS

The current evidence for charged-particle therapies in the management of sarcomas of the spine and sacrum is limited. Preliminary evidence suggests that with these therapies local control and OS at 5 years are comparable among various charged-particle options and may be similar between those treated with definitive charged-particle therapy and historical surgical cohorts. Further research directly comparing charged-particle and photon-based therapies is necessary.

Surgical Management of Skull Base and Spine Chordomas

OPINION STATEMENT

Management of chordoma along the cranial-spinal axis is a major challenge for both skull base and spinal surgeons. Although chordoma remains a rare tumor, occurring in approximately 1 per 1 million individuals, its treatment poses several challenges. These tumors are generally poorly responsive to radiation and chemotherapy, leading to surgical resection as the mainstay of treatment. Due to anatomic constraints and unique challenges associated with each primary site of disease, gross total resection is often not feasible and is associated with high rates of morbidity. Additionally, chordoma is associated with high rates of recurrence due to the tumor's aggressive biologic features, and postoperative radiation is increasingly incorporated as a treatment option for these patients. Despite these challenges, modern-day surgical techniques in both skull base and spinal surgery have facilitated improved patient outcomes. For example, endoscopic endonasal techniques have become the mainstay in resection of skull base chordomas, improving the ability to achieve gross total resection, while reducing associated morbidity of open transfacial techniques. Resection of spinal chordomas has been facilitated by emerging techniques in preoperative imaging, intraoperative navigation, spinal reconstruction, and radiotherapy. Taken collectively, the treatment of chordoma affecting the skull base and spinal requires a multidisciplinary team of surgeons, radiation oncologists, and medical oncologists who specialize in the treatment of this challenging disease.

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.

High-dose proton therapy and tomotherapy for the treatment of sacral chordoma: a retrospective monocentric study

OBJECTIVE

Radiation therapy (RT) is used for the treatment of sacral chordoma, in combination with surgery or alone for unresected tumours, to improve local control (LC) and potentially overall survival (OS). The purpose of the present study was to evaluate efficacy and toxicity of proton therapy (PT), and/or intensity modulated radiation therapy (IMRT), particularly Tomotherapy, for sacral chordoma treatment. Material: Between November 2005 and June 2018, 41 consecutive patients who were not included in clinical trials, received sacral chordoma radiation treatment in Institut Curie with Tomotherapy alone in 13 patients, and combined PT and Tomotherapy boost (Proton - Tomo) in 28 patients. RT was delivered as the exclusive local treatment in 11 patients, and as a post-operative complementary treatment in 30 patients.

RESULTS

After a median follow-up of 46 months (range, 0-125 months), eight local relapses were observed, and seven patients developed distant metastasis (particularly bone and lung). The 2- and 5- year local relapse rates were 11.4% CI (0.65-22.2%) and 29% (10.5-47.4%), respectively. Over the follow-up period, ten patients died (24.4%). The estimated 2- and 5-year OS rates were 91.4% CI (82.5-100%) and 74.5% (59.4-93.5%), respectively. Fibrosis, cauda equina syndrome, and pain were the most common late toxicities. The comparison between Tomotherapy alone and Proton - Tomo revealed that acute and late cystitis were significantly more frequent in the Tomotherapy group: SHR = 0.12 IC95% (0.01-0.90 [p = .04]), as well as late proctitis. A dosimetric comparison confirmed the interest of PT to spare rectum and bladder in this context.

CONCLUSION

RT remains essential to improve local control in sacral chordoma. The combination of proton and photon seems to improve organ at risk sparing, resulting in a decreased rate of reported late toxicities.

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

STUDY DESIGN

A retrospective data analysis was performed.

OBJECTIVE

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

SUMMARY OF BACKGROUND DATA

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

METHODS

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

RESULTS

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

CONCLUSION

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

LEVEL OF EVIDENCE

4.

Outcomes of chordomas of the sacrum and mobile spine: Clinical series with average 6-year follow-up

Study Design:

Retrospective clinical series.

Purpose:

To search for spinal chordoma's survival rates, recurrences, and complications and compare sacral and mobile spine chordomas.

Overview of Literature:

The primary spinal chordoma treatment is mainly considered radical surgery, although recurrence rates are pretty high. Radical surgery with extra marginal resection is possible with significant neurologic deficits and very high complication rates.

Materials and Methods:

This study reviews 48 spinal chordoma patients (sacrum 28, mobile spine 20) surgically treated between 1995 and 2019. Follow-up times ranged between 12 months and 238 months (average 6.16 years). Six patients were lost to follow-up after at least 1 year of control; three died 30 days after surgery.

Results:

Surgery for sacrum tumors was an extra marginal resection (sacrectomy) in 19 patients, while nine patients had intralesional surgery. There were 13 cervical chordomas and seven thoracolumbar chordomas. Although we tried marginal resections for cervical chordomas, all had positive margins, and we accepted them as intralesional. Surgery for thoracolumbar chordomas was total spondylectomy in four cases and intralesional excision in three patients. Because of recurrences, the average surgery per patient was 3.45. It was more common in mobile spine chordomas (average 4.2) than sacral chordomas (average 2.92). Surgical complications of mobile spine chordomas (15/20; 75%) were also more than sacral chordomas (16/28; 57%). Chordomas of the mobile spine had no metastasis, while sacral chordomas had a 21% (6/28) metastasis rate. The recurrence rates of sacral chordomas (16/21; 76%) were not significantly different from the mobile spine (15/18; 83%). Among sacral chordomas, in all five cases who had no recurrence, the level of sacrectomy was S2 and below.

Conclusions:

Recurrence and survival rates of mobile spine and sacral chordomas are not different. Sacral chordomas tend to metastasize. Sacrectomy is successful for sacral chordomas at S2 and below.

Radiation Strategies for Spine Chordoma: Proton Beam, Carbon Ions, and Stereotactic Body Radiation Therapy

Surgery alone provides suboptimal local control of spine and sacral chordomas. Radiotherapy (RT) may improve local control in patients undergoing surgery and be used as definitive-intent treatment in patients not undergoing surgery. Although conventional-dose RT is inadequate for these radioresistant tumors, newer techniques allow treatment of the tumor to higher, more effective doses while limiting spinal cord dose to safe levels. The best local control is achieved when RT is delivered in the primary setting; RT dose is a critical determinant of local control. RT should be considered for all spine and sacral chordoma patients.

A case-control study of computer navigation assisted resection of primary sacral chordoma above sacrum 3 level

•

This is a retrospective case-control study.

•

The computer navigation aided technology can make more cases achieve safe surgical margin.

•

The clear bone resection margins were achieved in all cases in navigation group.

•

The application of computer navigation doesn’t increase the operation time and intraoperative blood loss.

Background

The operation of sacral chordoma resection is difficult especial in the tumor above sacrum 3 level and the local recurrence rate was high. The purpose of this study is to analyze the effect of computer navigation aided technology in primary sacral chordoma resection above sacrum 3 level through a case-control study, which including perioperative safety, surgical margin, postoperative recurrence and function results.

Methods

This is a retrospective case-control study. The clinical data of 25 patients received initial computer-assisted resection of sacral chordoma above the level of sacrum 3 from 2009 to 2016 were analyzed; the patients underwent non-navigation assisted resection of tumor above the level of sacrum 3 in the same period were matched and 25 patients were selected randomly. There was no significant difference between these two groups in gender (P = 0.370), age (P = 0.554), tumor transverse diameter (P = 0.836). The average maximum diameter of tumor in navigation group was significant bigger than that in non-navigation group (P = 0.005). The intraoperative safety results, surgical margin, postoperative complications, recurrence rate and function were compared between these groups.

Results

There was no significant difference between navigation and non-navigation group in operative time (P = 0.105) and intraoperative blood loss (P = 0.537). There were 18 wide resections, 4 marginal resections and 3 intracapsular resections in navigation group; there were 6 wide resections, 12 marginal resections and 7 intracapsular resections in non-navigation group; the surgical margins of two groups were significant different (P = 0.003). There were 5 cases (20%) and 6 cases (24%) with wound complication in navigation group and non-navigation group (P = 0.733). The average follow-up was 49.6 (16–102) months in navigation group and 51.3 (12–110) months in non-navigation group. Three cases (12%) showed recurrence in navigation group and six cases showed recurrence (24%) in non-navigation group. The surgical margin was significantly related with tumor recurrence (P = 0.000). The average MSTS score was 27.3 (19–30) and 26.5 (20–29) in navigation group and non-navigation group (P = 0.374).

Conclusion

The computer navigation aided technology can improve the accuracy of primary sacral chordoma resection, and make more cases achieve safe surgical margin. Compared with the traditional operation, the application of computer navigation in the larger tumor resection does not increase the operation time and intraoperative blood loss, which shows good safety.

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.

The sacral chordoma margin

OBJECTIVE

Aim of the manuscript is to discuss how to improve margins in sacral chordoma.

BACKGROUND

Chordoma is a rare neoplasm, arising in half cases from the sacrum, with reported local failure in >50% after surgery.

METHODS

A multidisciplinary meeting of the "Chordoma Global Consensus Group" was held in Milan in 2017, focusing on challenges in defining and achieving optimal margins in chordoma with respect to surgery, definitive particle radiation therapy (RT) and medical therapies. This review aims to report on the outcome of the consensus meeting and to provide a summary of the most recent evidence in this field. Possible new ways forward, including on-going international clinical studies, are discussed.

RESULTS

En-bloc tumor-sacrum resection is the cornerstone of treatment of primary sacral chordoma, aiming to achieve negative microscopic margins. Radical definitive particle therapy seems to offer a similar outcome compared to surgery, although confirmation in comparative trials is lacking; besides there is still a certain degree of technical variability across institutions, corresponding to different fields of treatment and different tumor coverage. To address some of these questions, a prospective, randomized international study comparing surgery versus definitive high-dose RT is ongoing. Available data do not support the routine use of any medical therapy as (neo)adjuvant/cytoreductive treatment.

CONCLUSION

Given the significant influence of margins status on local control in patients with primary localized sacral chordoma, the clear definition of adequate margins and a standard local approach across institutions for both surgery and particle RT is vital for improving the management of these patients.

Surgical Treatment of Sacral Chordoma: The Role of Laparoscopy

Sacral chordoma is a rare tumour that represents the most common malignancy of the sacral region. Its diagnosis can be delayed because of unclear clinical manifestation. This tumour can involve surrounding anatomical structure such as the rectum, and its surgical treatment is still challenging. We report on 3 patients with sacral chordoma. Two of them were successfully treated using a laparoscopic approach and one by open surgery. We present all details of the surgical technique and patients' outcome. Minimally invasive methods in the surgical treatment of chordoma allow to perform a radical dissection of the tumour, minimizing the operative trauma. A laparoscopic approach can be considered safe and radical for sacral chordoma treatment.

Natural History of a Patient with Sacral Chordoma: Case Report and Literature Review

BACKGROUND

Chordomas are rare, slow-growing, locally aggressive, malignant tumors of the spine. Chordomas are conventionally treated with surgical resection with or without radiation. There is an absence of literature documenting the natural history of a primary sacral chordoma.

CASE DESCRIPTION

A 65-year-old man presented with rectal pain, constipation, urinary and fecal incontinence, S1 radiculopathy, and a palpable rectal mass. A needle biopsy confirmed the pathologic diagnosis of sacral chordoma. The patient declined to have surgery because of the surgical risks involved. He was managed conservatively with supportive care only. The patient was routinely followed in clinic and had a subjective and objective excellent quality of life with adequate pain management. Meanwhile, his neurologic status did not deteriorate. During follow-up, some posterolateral aspects of the chordoma regressed. However, the bulk of the lesion continued to slowly progress. The patient survived for 7.5 years. He eventually succumbed to urosepsis and new-onset peritoneal metastasis.

CONCLUSIONS

To our knowledge, the patient is the only documented case in the literature of an untreated biopsy-proven sacral chordoma. The patient's tumor was intended for resection, and therefore comparable with data from treated chordomas. The patient's survival is similar to the median survival in treated chordomas. The patient's survival was despite negative prognosticators, such as advanced age of the patient and high sacral location above S2.

Association of cancer center type with treatment patterns and overall survival for patients with sacral and spinal chordomas: an analysis of the National Cancer Database from 2004 to 2015

OBJECTIVE

Chordomas of the spine and sacrum are a rare but debilitating cancer and require complex multidisciplinary care. Studies of other such rare cancers have demonstrated an association of high-volume and/or multidisciplinary centers with improved outcomes and survival. Such an association has been proposed for chordomas, but evidence to support this claim is lacking. The authors performed a study to investigate if treatment facility type is associated with patterns of care and survival for patients with spinal and sacral chordomas by assessing records from a US-based cancer database.

METHODS

In this observational retrospective cohort study, the authors identified 1266 patients from the National Cancer Database with vertebral column or sacral chordomas diagnosed between 2004 and 2015. The primary study outcome was overall survival, and secondary outcomes included odds of receiving treatment and time to treatment, defined as radiation therapy, surgery, and/or any treatment, including surgery, radiation therapy, chemotherapy, or participation in clinical trials. The results were adjusted for age, sex, race/ethnicity, level of education, income, and Charlson/Deyo score.

RESULTS

Of the 1266 patients identified, the mean age at diagnosis was 59.70 years (SD 16.2 years), and the patients were predominantly male (n = 791 [62.50%]). Patients treated at community cancer programs demonstrated an increased risk of death (HR 1.98, 95% CI 1.13-3.47, p = 0.018) when compared to patients treated at academic/research programs (ARPs). The median survival was longest for those treated at ARPs (131.45 months) compared to community cancer programs (79.34 months, 95% CI 48.99-123.17) and comprehensive community cancer programs (CCCPs) (109.34 months, 95% CI 84.76-131.45); 5-year survival rates were 76.08%, 52.71%, and 61.57%, respectively. Patients treated at community cancer programs and CCCPs were less likely to receive any treatment compared to those treated at ARPs (OR 6.05, 95% CI 2.62-13.95, p < 0.0001; OR 3.74, 95% CI 2.23-6.28, p < 0.0001, respectively). Patients treated at CCCPs and community cancer programs were less likely to receive surgery than those treated at ARPs (OR 2.69, 95% CI 1.82-3.97, p = 0.010; OR = 2.64, 95% CI 1.22-5.71, p = 0.014, respectively). Patients were more likely to receive any treatment (OR 0.59, 95% CI 0.40-0.87, p = 0.007) and surgery (OR 0.58, 95% CI 0.38-0.88, p < 0.0001) within 30 days at a CCCP compared to an ARP. There were no differences in odds of receiving radiation therapy or time to radiation by facility type.

CONCLUSIONS

Clinical care at an ARP is associated with increased odds of receiving treatment that is associated with improved overall survival for patients with spinal and sacral chordomas, suggesting that ARPs provide the most comprehensive specialized care for patients with this rare and devastating oncological disease.

High expression of survivin independently correlates with tumor progression and mortality in patients with skull base chordomas

OBJECTIVE

The object of this study was to clarify the expression characteristics and prognostic value of survivin in skull base chordomas.

METHODS

In this retrospective study, the authors measured the expression of survivin at the mRNA level in 81 samples from 71 patients diagnosed with skull base chordomas at their hospital in the period from July 2005 to January 2015. Clinical data collection, follow-up, and survival analyses were performed, and correlations were analyzed.

RESULTS

Of the 71 patients, 50 had primary chordomas with a mean survivin expression level of 1.09; the other 21 patients had recurrent chordomas with a mean survivin expression level of 2.57, which was 2.36 times higher than the level in the primary chordoma patients (p < 0.001, Mann-Whitney U-test). In addition, an analysis of 18 paired samples derived from 9 patients showed that the expression level of survivin was 2.62 times higher in recurrent tumors than in primary tumors (p = 0.002, paired t-test). The Spearman rank correlation coefficient method showed that the expression level of survivin was positively correlated with the mean ratio of tumor signal intensity to the signal intensity of surrounding brainstem on T1-weighted sequences (RT1; rs = 0.274, p = 0.021) and was negatively correlated with the mean ratio of tumor signal intensity to the signal intensity of surrounding brainstem on T2-weighted sequences (RT2; rs = -0.389, p = 0.001). A multivariate Cox proportional-hazards model suggested that pathology (p = 0.041), survivin expression level (p = 0.018), preoperative Karnofsky Performance Status (KPS; p = 0.012), and treatment history (p = 0.009) were independent prognostic factors for tumor progression. Survivin expression level (p = 0.008), preoperative KPS (p = 0.019), tumor diameter (p = 0.027), and intraoperative blood loss (p = 0.015) were independent prognostic factors for death.

CONCLUSIONS

Survivin expression level and preoperative KPS were independent significant prognostic factors for tumor progression and death in skull base chordoma patients. Recurrent skull base chordomas and chordomas with high RT1 and low RT2 were likely to have high survivin expression. Other independent risk factors related to tumor progression included conventional pathology and treatment history, whereas additional mortality-related risk factors included larger tumor diameter and greater intraoperative blood loss.

Sacral chordoma: do the width of surgical margin and the use of photon/proton radiotherapy affect local disease control?

PURPOSE

Chordoma is a rare but highly aggressive primary bone sarcoma that arises commonly from the sacrum. While en bloc resection has been the mainstay of the treatment, the role of resection margin in millimetres with/without adjuvant radiotherapy (RT) has been unknown. We investigated the prognostic impact of surgical margin width, adjuvant RT, and their combined factor for sacral chordoma.

METHODS

Forty-eight patients who underwent surgical treatment between 1996 and 2016 were studied. Of these, 11 patients (23%) received adjuvant RT; photon RT in 7 (15%) and proton RT in 4 (8%). Margins were microscopically measured in millimetres from the resection surface to the closest tumour on histologic slides.

RESULTS

The five year and ten year disease-specific survival was 88% and 58%, respectively, and the local recurrence (LR) rate was 48%. The LR rate with 0-mm, < 1.5-mm, and ≥ 1.5-mm margin was 50% (group 1), 50% (group 2: RT-, 61%; group 3: RT+, 14%), and 0% (group 4), respectively. We observed a significantly lower LR rate in patients with adjuvant photon/proton RT (18%) than without it (57%; p = 0.026), and no LR was observed after post-operative proton RT. The combined factor of margin with RT clearly stratified the LR risk: patients of group 1 (positive margin) and 2 (< 1.5-mm margin, RT-) had approximately 7.5× LR risk (p = 0.049) compared with those of group 3 (< 1.5-mm margin, RT+) and 4 (≥ 1.5-mm margin).

CONCLUSION

This study identified the lowest risk of local failure in tumour resection with ≥ 1.5-mm margin or negative but < 1.5-mm margin with the use of adjuvant photon/proton radiotherapy for sacral chordoma. Early results of adjuvant proton RT demonstrated excellent local control.

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.

Prognostic significance of human telomerase reverse transcriptase promoter region mutations C228T and C250T for overall survival in spinal chordomas

BACKGROUND

Spinal chordomas, a subtype of primary spinal column malignancies (PSCM), are rare tumors with poor prognosis, and we have limited understanding of the molecular drivers of neoplasia.

METHODS

Study design was a retrospective review of prospectively collected data with cross-sectional survival. Archived paraffin embedded pathologic specimens were collected for 133 patients from 6 centers within Europe and North America between 1987 and 2012. Tumor DNA was extracted and the human telomerase reverse transcriptase (hTERT) promoter was sequenced. The hTERT mutational status was correlated with overall survival (OS) and time to first local recurrence.

RESULTS

Ninety-two chordomas, 26 chondrosarcomas, 7 osteosarcomas, 3 Ewing's sarcomas, and 5 other malignant spinal tumors were analyzed. Median OS following surgery was 5.8 years (95% CI: 4.6 to 6.9) and median time to first local recurrence was 3.9 years (95% CI: 2.5 to 6.7). Eight chordomas, 2 chondrosarcomas, 1 Ewing's sarcoma, and 1 other malignant spinal tumor harbored either a C228T or C250T mutation in the hTERT promoter. In the overall cohort, all patients with hTERT mutation were alive at 10 years postoperative with a median OS of 5.1 years (95% CI: 4.5 to 6.6) (P = 0.03). hTERT promoter mutation was observed in 8.7% of spinal chordomas, and 100% of chordoma patients harboring the mutation were alive at 10 years postoperative compared with 67% patients without the mutation (P = 0.05).

CONCLUSIONS

We report for the first time that hTERT promoter mutations C228T and C250T are present in approximately 8.7% of spinal chordomas. The presence of hTERT mutations conferred a survival benefit and could potentially be a valuable positive prognostic molecular marker in spinal chordomas.

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.

Image guidance in spine tumor surgery

Beginning with basic stereotactic operative methods in neurosurgery, intraoperative navigation and image guidance systems have since become the norm in that field. Following the introduction of image guidance into spinal surgery, there has been a dramatic increase in its utilization across disciplines and pathologies. Spine tumor surgery encompasses a wide range of complex surgical techniques and treatment strategies. Similarly to deformity correction and trauma surgery, spine navigation holds potential to improve outcomes and optimize surgical technique for spinal tumors. Recent data demonstrate the applicability of neuro-navigation in the field of spinal oncology, particularly for spinal stabilization, maximizing extent of resection and integration of minimally invasive therapies. The rapid introduction of new, less invasive, and ablative surgical techniques in spine oncology coupled with the rising incidence of spinal metastatic disease make it imperative for spine surgeons to be familiar with the indications for and limitations of imaging guidance. Herein, we provide a practical, current concepts narrative review on the use of spinal navigation in three areas of spinal oncology: (a) extent of tumor resection, (b) spinal column stabilization, and (c) focal ablation techniques.

Primary Bone Tumor of the Spine-An Evolving Field: What a General Spine Surgeon Should Know

STUDY DESIGN

A narrative review of the literature.

OBJECTIVE

This article reviews the general principles of treatment and investigation for primary bone tumors of the spine. Furthermore, it explores the emerging alternatives.

METHODS

A review was performed using Medline, Embase, and Cochrane databases.

RESULTS

Primary bone tumors of the spine are rare entities that general spine surgeons may encounter only a few times in their career. The treatment algorithm of these complex tumors is filled with nuances and is evolving constantly. For these reasons, patients should be referred to experienced tertiary or quaternary centers who can offer a comprehensive multidisciplinary approach. For most malignant spinal bone tumors, surgery remains the cornerstone of treatment. Respecting oncologic principles has been associated with improved survival and decreased local recurrence in multiple settings. However, even in experienced centers, these surgeries carry a significant risk of adverse events and possible long-term neurologic impairment. The associated morbidity of these procedures and the challenges of local recurrence have encouraged professionals caring for these patients to explore alternatives or adjuncts to surgical treatment.

CONCLUSIONS

Over the past few years, several advances have occurred in medical oncology, radiation oncology and interventional radiology, changing the treatment paradigm for some tumors. Other advances still need to be refined before being applied in a clinical setting.

Pediatric extraosseous sacral chordoma: case report and literature review of embryonic derivation and clinical implications

An extraosseous intradural presentation for a sacral chordoma in the pediatric age group has not been reported to date. This is a report on an 11-year-old boy who presented with an extraosseous, intradural sacral chordoma. He underwent gross-total resection and received adjuvant proton beam therapy. Neoplastic transformation of the notochord is reviewed to illustrate the developmental basis for the surgical anatomy and pathogenesis of the classic chordoma variant. Clinical and pathological features are reviewed to differentiate this chordoma presentation from classic osseous chordomas and ecchordosis physaliphora, a related benign developmental notochordal lesion. Finally, the role of developmental signaling in the pathogenesis of chordomas from postembryonic notochordal tissue is discussed.

Rectotumoral fistula formation occurring more than 5 years after carbon ion radiotherapy for sacral chordoma: A case report

Chordoma is a rare tumor that originates from the notochord. Half of chordomas involve the sacral region. Surgery is considered to be the standard treatment for sacral chordoma. However, carbon ion radiotherapy (CIRT) has recently emerged as a promising treatment for unresectable sacral chordoma. Little is known about the long-term complications of CIRT. We present two cases of rectotumoral fistula formation that occurred >5 years after CIRT for sacral chordoma. We considered two possible explanations for fistula formation: radiation enterocolitis after CIRT might cause formation of the fistula long-term, and tumor regrowth might compress the rectum and cause fistula formation. A biopsy in Case 1 showed that regrowth tumor was post-CIRT. It is important to be aware of the possibility of rectal complications after CIRT, and if found, resection of the rectum should be considered. This is a first report of rectotumoral fistula formation that occurred >5 years after CIRT for sacral chordoma.

Solamargine inhibits proliferation and promotes apoptosis of CM-319 human chordoma cells through suppression of notch pathway

Background

Solamargine (SM), which represents a natural steroid alkaloid glycoside compound and a cytotoxic agent, has been proved to enhance the sensitivity of lung cancer cells to tumor necrosis factors (TNFs). In this study, we aimed to investigate the roles and mechanisms of SM in chordoma.

Methods

Cell viability, proliferation, apoptosis and cell cycle were measured by cell counting Kit-8 (CCK-8) assay, 5(6)-carboxyfluorescein diacetate succinimidyl ester (CFSE) labeling and flow cytometry (FCM), respectively. Western blot and quantitative real-time reverse transcription PCR (qRT-PCR) assays were performed to detect the expressions of related mRNAs and proteins.

Results

The results revealed that SM distinctly suppressed the proliferation of CM-319 cells. SM significantly induced the CM-319 cells apoptosis through up-regulating the expression levels of Caspase-3/8/9. The cell cycle of CM-319 cells was blocked by SM in G1 phase. Moreover, SM could significantly suppress the Notch pathway in CM-319 cells.

Conclusions

In conclusion, SM suppressed the proliferation and enhanced the apoptosis ability of CM-319 cells via suppressing the Notch pathway. The results suggested that SM might be a novel therapeutic agent and supported the utilization of SM in chordoma.

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.

Perilesional Resection of Glioblastoma Is Independently Associated With Improved Outcomes

BACKGROUND

Resection is a critical component in the initial treatment of glioblastoma (GBM). Often GBMs are resected using an intralesional method. Circumferential perilesional resection of GBMs has been described, but with limited data.

OBJECTIVE

To conduct an observational retrospective analysis to test whether perilesional resection produced a greater extent of resection.

METHODS

We identified all patients with newly diagnosed GBM who underwent resection at our institution from June 1, 1993 to December 31, 2015. Demographics, presenting symptoms, intraoperative data, method of resection (perilesional or intralesional), volumetric imaging data, and postoperative outcomes were obtained. Complete resection (CR) was defined as 100% resection of all contrast-enhancing disease. Univariate analyses employed analysis of variance (ANOVA) and Fisher's exact test. Multivariate analyses used propensity score-weighted multivariate logistic regression.

RESULTS

Newly diagnosed GBMs were resected in 1204 patients, 436 tumors (36%) perilesionally and 766 (64%) intralesionally. Radiographic CR was achieved in 69% of cases. Multivariate analysis demonstrated that perilesional tumor resection was associated with a significantly higher rate of CR than intralesional resection (81% vs 62%, multivariate odds ratio = 2.5, 95% confidence interval: 1.8-3.4, P < .001). Among tumors in eloquent cortex, multivariate analysis showed that patients who underwent perilesional resection had a higher rate of CR (79% vs 58%, respectively, P < .001) and a lower rate of neurological complications (11% vs 20%, respectively, P = .018) than those who underwent intralesional resection.

CONCLUSION

Circumferential perilesional resection of GBM is associated with significantly higher rates of CR and lower rates of neurological complications than intralesional resection, even for tumors arising in eloquent locations. Perilesional resection, when feasible, should be considered as a preferred option.

Current treatment strategy for newly diagnosed chordoma of the mobile spine and sacrum: results of an international survey

OBJECTIVEThe purpose of this study was to investigate the spectrum of current treatment protocols for managing newly diagnosed chordoma of the mobile spine and sacrum.METHODSA survey on the treatment of spinal chordoma was distributed electronically to members of the AOSpine Knowledge Forum Tumor, including neurosurgeons, orthopedic surgeons, and radiation oncologists from North America, South America, Europe, Asia, and Australia. Survey participants were pre-identified clinicians from centers with expertise in the treatment of spinal tumors. The suvey responses were analyzed using descriptive statistics.RESULTSThirty-nine of 43 (91%) participants completed the survey. Most (80%) indicated that they favor en bloc resection without preoperative neoadjuvant radiation therapy (RT) when en bloc resection is feasible with acceptable morbidity. The main area of disagreement was with the role of postoperative RT, where 41% preferred giving RT only if positive margins were achieved and 38% preferred giving RT irrespective of margin status. When en bloc resection would result in significant morbidity, 33% preferred planned intralesional resection followed by RT, and 33% preferred giving neoadjuvant RT prior to surgery. In total, 8 treatment protocols were identified: 3 in which en bloc resection is feasible with acceptable morbidity and 5 in which en bloc resection would result in significant morbidity.CONCLUSIONSThe results confirm that there is treatment variability across centers worldwide for managing newly diagnosed chordoma of the mobile spine and sacrum. This information will be used to design an international prospective cohort study to determine the most appropriate treatment strategy for patients with spinal chordoma.

Predictive Value of Preoperative Magnetic Resonance Imaging Findings for Survival and Local Recurrence in Patients Undergoing En Bloc Resection of Sacral Chordomas

BACKGROUND

Few studies have assessed the prognostic importance of preoperative magnetic resonance imaging (MRI) scan findings in patients undergoing en bloc resection of sacral chordomas.

OBJECTIVE

To (1) report in-depth imaging characteristics of sacral chordomas, (2) describe the patterns of local and distant recurrence, and (3) determine imaging predictors of overall survival (OS) and local recurrence (LR).

METHODS

This retrospective case series was obtained from a prospectively maintained spine database from 1995 to 2016. All patients underwent en bloc resection of sacral chordomas. Detailed demographic, outcome, and MRI data were collected. A survival analysis was completed with multivariable cox regression to assess the impact of MRI findings on OS and LR.

RESULTS

A total of 41 patients underwent en bloc resection of sacral chordoma with preoperative MRI scans. Tumor characteristics included lobulated: (93%) and soft tissue tail (54%). The following areas had tumor invasion lobulated: sacroiliac (SI) joint (15%), ilium (5%), piriformis (61%), gluteus (46%), subcutaneous fat (32%), and lumbosacral venous plexus (22%). After multivariable analysis, only subcutaneous fat extension was an independent predictor of decreased OS (hazard ratio 5.30, 95% confidence interval 1.47-19.19, P = .011). Though not significant after multivariable analysis, the following factors were significant predictors of LR after univariate logrank testing: above the L5/S1 disc space (P = .004), SI joint invasion (P = .036), and piriformis extension (P = .022).

CONCLUSION

The presence of subcutaneous fat extension was an independent predictor of decreased OS. Other MRI findings with potential for future evaluation include size, presence of soft tissue tail, extension above L5/S1, and SI joint and piriformis invasion.