Surgical management of primary bone tumors of the spine: validation of an approach to enhance cure and reduce local recurrence

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Outcomes After Definitive Surgery for Spinal and Sacral Chordoma in 101 Patients Over 20 Years

BACKGROUND AND OBJECTIVES

Spinal chordomas are primary bone tumors where surgery remains the primary treatment. However, their low incidence, lack of evidence, and late disease presentation make them challenging to manage. Here, we report the postoperative outcomes of a large cohort of patients after surgical resection, investigate predictors for overall survival (OS) and local recurrence-free survival (LRFS) times, and trend functional outcomes over multiple time periods.

METHODS

Retrospective review of all patients followed for spinal chordoma at a quaternary spinal oncology center from 2003 to 2023 was included. Data were collected regarding demographics, preoperative and perioperative management, and follow-up since initial definitive surgery. Primary outcomes were OS and LRFS, whereas secondary outcomes were functional deficits.

RESULTS

One hundred one patients had an average follow-up of 6.0 ± 4.2 years. At the time of census, 25/101 (24.8%) had experienced a recurrence and 10/101 (9.9%) had died. After surgery, patients experienced a significant decrease in pain over time, but rates of sensory deficits, weakness, and bowel/bladder dysfunction remained static. Tumors ≥100 cm3 (hazard ratio (HR) = 5.89, 95% CI 1.72-20.18, P = .005) and mobile spine chordomas (HR = 7.73, 95% CI 2.09-28.59, P = .002) are related to worse LRFS, whereas having neoadjuvant radiotherapy is associated with improved LRFS (HR = 0.09, 95% CI 0.01-0.88, P = .038). On the other hand, being age ≥65 years was associated with decreased OS (HR = 16.70, 95% CI 1.54-181.28, P = .021).

CONCLUSION

Surgeons must often weigh the pros and cons of en bloc resection and sacrificing important but affected native tissues. Our findings can provide a benchmark for counseling patients with spinal chordoma. Tumors ≥100 cm3 appear to have a 5.89-times higher risk of recurrence, mobile spine chordomas have a 7.73 times higher risk, and neoadjuvant radiotherapy confers an 11.1 times lower risk for local recurrence. Patients age ≥65 years at surgery have a 16.70 times higher risk of mortality than those <65 years.

Sagittal en bloc resection of thoracolumbar tumours: a report of thirty one cases

PURPOSE

To develop a novel classification of sagittal en bloc resection (SEBR) based on anatomical locations for thoracolumbar spine tumors and assess the clinical outcomes of this surgical procedure.

METHODS

31 patients with thoracolumbar tumours treated with SEBR were enrolled in this study. The individualized surgical strategy was adopted based on our surgical classification. Demographics, perioperative outcomes, complications and postoperative outcomes were assessed.

RESULTS

Based on our surgical classifications, patients were divided into four types. All bony resection margins were negative, wide resection was achieved in 25 patients, marginal resection in four, and intralesional resection in two. 18 patients underwent anterior reconstruction. Complications were encountered in five patients, and instrumentation failure occurred in one patient. The median follow-up was 24 (range, 6-72) months and recurrence was found in only one patient.

CONCLUSION

SEBR is a safe and effective surgical procedure for patients with thoracolumbar spinal tumours in specific anatomical locations. The proposed surgical classification covers all SEBR types and is easy to apply, it may assist surgical decision-making in patients with spinal tumours.

New technique of En bloc vertebral resection in the thoracolumbar region assisted by retroperitoneal laparoscopy in a single prone position: first results

PURPOSE

To describe the technique and review the oncological and surgical results of the En Bloc resection assisted by retroperitoneal laparoscopy in a single prone position for tumors in the thoracolumbar region.

METHODS

Monocentric retrospective case study. Procedure was performed in a single prone position by a dual team of spine and thoracovascular surgeons. An endoscopic balloon was inflated in the right retroperitoneal cavity. A plan was developed between the anterior spine and vena cava as well as abdominal aorta with segmental vessels ligation. Structures at risk were safely protected under endoscopy during horizontal or sagittal osteotomies.

RESULTS

From 2021, seven patients aged a median 52 years old (range, 34-67) were included. Involved spinal segments went from T11 to L3. Surgery was aborted in one case due to massive bleeding and ventilating difficulties. There were two partial and four total vertebral resections. Median operating duration and estimated blood loss were 405 min (range, 360-540) and 2.1 L (range, 1.2-19), respectively. Postoperative complications consisted of 1 urinary infection; 1 transient urinary retention; 1 posterior wound infection; 1 pneumothorax; 1 persistent partial motor deficit; 1 transient confusion; 1 pulmonary embolism; 1 CSF leak; 1 subdural hematoma; 1 retroperitoneal lymphocele. All margins were uncontaminated. All patients were alive and ambulatory at last follow-up.

CONCLUSION

Early results suggest En Bloc resection assisted by retroperitoneal videoscopy in tumors from T11 to L3/4 disk space is feasible, less invasive and safe. Careful surgical planning and experience in endoscopic vascular surgery are mandatory.

Does Preoperative Bilsky Score Predict Outcome Following Surgical Resection of Primary Tumors of the Spine?

OBJECTIVE

In patients undergoing surgery for primary bone tumors of the spine, we sought to compare Bilsky score 0-1 versus 2-3 in: 1) preoperative presentation, 2) perioperative variables, and 3) long-term outcomes.

METHODS

A single-center, retrospective cohort study was undertaken of patients undergoing surgery for extradural, primary bone tumors of the spine between January 2010 and January 2021. The primary exposure variable was Bilsky score, dichotomized as 0-1 versus 2-3. Survival analysis was performed to assess local recurrence (LR) and overall survival (OS).

RESULTS

Of 38 patients undergoing resection of primary spinal tumors, 19 (50.0%) patients presented with Bilsky 0-1 and 19 (50.0%) Bilsky 2-3 grades. The most common diagnosis was chondrosarcoma (33.3%), followed by chordoma (16.7%). There were 15 (62.5%) malignant tumors. Preoperatively, there was no significant difference in demographics, Karnofsky Performance Scale (KPS) (P > 0.999), or motor deficit (P > 0.999). Perioperatively, no difference was found in operative time (P = 0.954), blood loss (P = 0.416), length of stay (P = 0.641), neurologic deficit (P > 0.999), or discharge disposition (P = 0.256). No difference was found in Enneking resection status (69.2% vs. 54.5%, P = 0.675). Long-term, no differences were found regarding reoperation (P = 0.327), neurologic deficit (P > 0.999), postoperative KPS (P = 0.605) and modified McCormick Scale (MMS) (P = 0.870). No difference was observed in KPS (P = 0.418) and MMS (P = 0.870) at last follow-up. However, patients with Bilsky 2-3 had shorter time to LR (1715.0 vs. 513.0 ± 633.4 days, log-rank; P = 0.002) and shorter OS (2025.0 ± 1165.3 vs. 794.0 ± 952.6 days, log-rank; P = 0.002).

CONCLUSIONS

Bilsky 2-3 lesions were associated with shorter time to LR and shorter OS. Patients harboring primary spinal tumors with higher grade Bilsky score appear to be at a higher risk for worse outcomes.

Gross total resection and survival outcomes in elderly patients with spinal chordoma: a SEER-based analysis

Objective

The association between aggressive resection and improved survival for adult spinal chordoma patients has not been well characterized in the geriatric population. Thus, the present study aimed to elucidate the relationship between gross total resection (GTR) and survival outcomes for patients across different age groups.

Methods

The authors isolated all adult patients diagnosed with spinal chordoma from the 2000-2019 Surveillance, Epidemiology, and End Results database and divided patients into three surgical subgroups: no surgery, subtotal resection (STR), and GTR. Kaplan-Meier curves with a log-rank test were used to discern differences in overall survival (OS) between surgical subgroups. Univariate and multivariate analyses were used to identify prognostic factors of mortality.

Results

There were 771 eligible patients: 227 (29.4%) received no surgery, 267 (34.6%) received STR, and 277 (35.9%) received GTR. Patients receiving no surgery had the lowest 5-year OS (45.2%), 10-year OS (17.6%), and mean OS (72.1 months). After stratifying patients by age, our multivariate analysis demonstrated that patients receiving GTR aged 40-59 (HR=0.26, CI=0.12-0.55, p<0.001), 60-79 (HR=0.51, CI=0.32-0.82, p=0.005), and 80-99 (HR=0.14, CI=0.05-0.37, p<0.001) had a lower risk of mortality compared to patients undergoing no surgery. The frequency of receiving GTR also decreased as a function of age (16.4% [80-99 years] vs. 43.2% [20-39 years]; p<0.001), but the frequency of receiving radiotherapy was comparable across all age groups (48.3% [80-99 years] vs. 45.5% [20-39 years]; p=0.762).

Conclusion

GTR is associated with improved survival for middle-aged and elderly patients with spinal chordoma. Therefore, patients should not be excluded from aggressive resection on the basis of age alone. Rather, the decision to pursue surgery should be decided on an individual basis.

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.

Surgical Treatments and Long-Term Outcomes for Pediatric Patients With Lumbar Spinal Tumors

STUDY DESIGN

Retrospective case‒control study.

OBJECTIVES

This study aimed to report the effects of surgical intervention on spinal stability recovery and to assess the long-term outcomes of children and adolescents with lumbar tumors.

METHODS

From January 2016 to June 2021, 42 pediatric patients with lumbar tumors were selected and separated into different groups based on the surgical method used (total en bloc resection (TER) group, n = 21; piecemeal resection (PR) group, n = 21; titanium mesh (TM) group n = 23; artificial vertebrae (AV) group n = 19). The clinicopathological characteristics, treatments and related outcomes were described in detail and compared between groups, with P value ≤.05 indicating statistically significant differences.

RESULTS

The average follow-up duration was 24.89 months, and the mean age was 14.89 ± 2.41 years. There were no significant differences in the mean operation time, average blood loss, complication rate, or length of hospital stay between the groups. The ODI, VAS and JOA scores at the final follow-up (FF) were elevated after surgery in all groups. The FF local angular drift (LOD) and lumbar angular drift (LUD) were greater in the TM group than in the AV group (P = .03, P = .001).

CONCLUSIONS

After surgery, pediatric patients with lumbar tumors can obtain satisfactory spinal stability, effective relief of pain symptoms and substantial improvements in neurological function. There was no significant difference in the invasiveness, safety or timeliness between the 2 surgical methods, so TER is recommended due to its low postoperative recurrence rate and good local control. Spinal fusion in the AV group resulted in better spinal stability.

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.

Outcomes of Recurrent Mobile Spine Chordomas

INTRODUCTION

Chordomas of the mobile spine are rare malignant tumors. The purpose of this study was to review the outcomes of treatment for patients with recurrent mobile spine chordomas.

METHODS

The oncologic outcomes and survival of 30 patients undergoing treatment of a recurrent mobile spine chordoma were assessed over a 24-year period. The mean follow-up was 3.5 years.

RESULTS

In patients presenting with a recurrent mobile spine chordoma, the mean 2- and 5-year overall survival was 73% and 39%, respectively. Enneking appropriate resection trended toward improved overall survival at 5 years (100% vs. 32%, P = 0.24). Those undergoing surgical resection for recurrence had improved metastatic-free survival (hazard ratio 0.29, CI 0.08 to 0.99, P = 0.05). Positive margins were found to be a risk factor of further local recurrence (hazard ratio 7.92, CI 1.02 to 61.49, P = 0.04). Those undergoing nonsurgical management trended toward having an increase in new neurologic deficits (P = 0.09), however, there was no difference in overall complications based on treatment type (P = 0.13).

CONCLUSION

Recurrent mobile spine chordoma portends a poor prognosis with an overall survival of less than 40% at 5 years. Surgical resection may help prevent new neurologic deficits and tumor metastasis while en bloc excision with negative surgical margins is associated with improved local recurrence-free survival.

Development and validation of nomograms predicting overall and cancer-specific survival for non-metastatic primary malignant bone tumor of spine patients

At present, no study has established a survival prediction model for non-metastatic primary malignant bone tumors of the spine (PMBS) patients. The clinical features and prognostic limitations of PMBS patients still require further exploration. Data on patients with non-metastatic PBMS from 2004 to 2015 were extracted from the Surveillance, Epidemiology, and End Results (SEER) database. Multivariate regression analysis using Cox, Best-subset and Lasso regression methods was performed to identify the best combination of independent predictors. Then two nomograms were structured based on these factors for overall survival (OS) and cancer-specific survival (CSS). The accuracy and applicability of the nomograms were assessed by area under the curve (AUC) values, calibration curves and decision curve analysis (DCA). Results: The C-index indicated that the nomograms of OS (C-index 0.753) and CSS (C-index 0.812) had good discriminative power. The calibration curve displays a great match between the model's predictions and actual observations. DCA curves show our models for OS (range: 0.09-0.741) and CSS (range: 0.075-0.580) have clinical value within a specific threshold probability range compared with the two extreme cases. Two nomograms and web-based survival calculators based on established clinical characteristics was developed for OS and CSS. These can provide a reference for clinicians to formulate treatment plans for patients.

Spinal tumours: recommendations of the Polish Society of Spine Surgery, the Polish Society of Oncology, the Polish Society of Neurosurgeons, the Polish Society of Oncologic Surgery, the Polish Society of Oncologic Radiotherapy, and the Polish Society of Orthopaedics and Traumatology

PURPOSE

The purpose of these recommendations is to spread the available evidence for evaluating and managing spinal tumours among clinicians who encounter such entities.

METHODS

The recommendations were developed by members of the Development Recommendations Group representing seven stakeholder scientific societies and organizations of specialists involved in various forms of care for patients with spinal tumours in Poland. The recommendations are based on data yielded from systematic reviews of the literature identified through electronic database searches. The strength of the recommendations was graded according to the North American Spine Society's grades of recommendation for summaries or reviews of studies.

RESULTS

The recommendation group developed 89 level A-C recommendations and a supplementary list of institutions able to manage primary malignant spinal tumours, namely, spinal sarcomas, at the expert level. This list, further called an appendix, helps clinicians who encounter spinal tumours refer patients with suspected spinal sarcoma or chordoma for pathological diagnosis, surgery and radiosurgery. The list constitutes a basis of the network of expertise for the management of primary malignant spinal tumours and should be understood as a communication network of specialists involved in the care of primary spinal malignancies.

CONCLUSION

The developed recommendations together with the national network of expertise should optimize the management of patients with spinal tumours, especially rare malignancies, and optimize their referral and allocation within the Polish national health service system.

Outcomes of Surgical Treatment for Extradural Benign Primary Spinal Tumors in Patients Younger than 25 Years: An Ambispective International Multicenter Study

Extradural primary spinal tumors were retrospectively analyzed from a prospective database of 1495 cases. All subjects with benign primary tumors under the age of 25 years, who were enrolled between 1990 and 2012 (Median FU was 2.4 years), were identified. Patient- and case-related characteristics were collected and statistically analyzed. Results: 161 patients (66f;95m; age 17.0 ± 4.7 years at time of diagnosis) were identified. The most common tumors were osteoblastomas n = 53 (32.9%), osteoid osteomas n = 45 (28.0%), and aneurysmal bone cysts n = 32 (19.9%). The tumor grade, according to the Enneking Classification S1/S2/S3, was 14/73/74 (8.7/45.3/46.0%), respectively. Tumor-related pain was present in 156 (96.9%) patients. Diagnosis was achieved by biopsies in 2/3 of the cases. Spinal fixation was used in >50% of the cases. Resection was Enneking appropriate in n = 100 (62.1%) of cases. Local recurrence occurred in 21 (13.1%) patients. Two patients died within a 10-year follow-up period. Conclusion: This is one of the largest international multicenter cohorts of young patients surgically treated for benign spinal tumors. The heterogenic young patient cohort presented at a mid-term follow-up without a correlation between the grade of aggressiveness in resection and local recurrence rates. Further prospective data are required to identify prognostic factors that determine oncological and functional outcomes for young patients suffering from these rare tumors.

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

Objectives

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

Methods

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

Results

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

Conclusions

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

En bloc resection of huge primary tumors with epidural involvement in the mobile spine using the “rotation–reversion” technique: Feasibility, safety, and clinical outcome of 11 cases

Background

En bloc resection of spinal tumors provides better local control and survival outcomes than intralesional resection. Safe margins during en bloc resection of primary spinal tumors with epidural involvement are required for improved outcomes. The present study describes a “rotation–reversion” technique that has been used for en bloc resection of huge primary tumors in the mobile spine with epidural involvement and reported the clinical outcomes in these patients.

Methods

All patients with primary spinal tumors who were treated with the rotation–reversion technique at our institution between 2015 and 2021 were evaluated retrospectively. Of the patients identified, those with both huge extraosseous soft-tissue masses and epidural involvement were selected for a case review. Clinical and radiological characteristics, pathologic findings, operative procedures, complications, and oncological and functional outcomes of these patients were reviewed.

Results

Of the 86 patients identified with primary spinal tumors who underwent en bloc resection using the rotation–reversion technique between 2015 and 2021, 11 had huge extraosseous soft-tissue masses with epidural involvement in the mobile spine. The average maximum size of these 11 tumors was 8.1 × 7.5 × 9.7 cm. Median follow-up time was 28.1 months, mean operation time was 849.1 min (range 465–1,340 min), and mean blood loss was 6,972.7 ml (range 2,500–17,700 ml), with 10 (91%) of the 11 patients experiencing perioperative complications. The negative margin rate was 91%, with only one patient (9%) experiencing local recurrence. Ten patients were able to walk normally or with a crutch at the last follow-up, whereas one was completely paralyzed preoperatively.

Conclusion

The rotation–reversion technique is an effective procedure for the en bloc resection of huge primary spinal tumors, with the extension of invasion in selected patients including not only the vertebral body but also the pedicle and part of the posterior arch.

Augmented Reality Neuronavigation for En Bloc Resection of Spinal Column Lesions

BACKGROUND

Primary tumors involving the spine are relatively rare but represent surgically challenging procedures with high patient morbidity. En bloc resection of these tumors necessitates large exposures, wide tumor margins, and poses risks to functionally relevant anatomical structures. Augmented reality neuronavigation (ARNV) represents a paradigm shift in neuronavigation, allowing on-demand visualization of 3D navigation data in real-time directly in line with the operative field.

METHODS

Here, we describe the first application of ARNV to perform distal sacrococcygectomies for the en bloc removal of sacral and retrorectal lesions involving the coccyx in 2 patients, as well as a thoracic 9-11 laminectomy with costotransversectomy for en bloc removal of a schwannoma in a third patient.

RESULTS

In our experience, ARNV allowed our teams to minimize the length of the incision, reduce the extent of bony resection, and enhanced visualization of critical adjacent anatomy. All tumors were resected en bloc, and the patients recovered well postoperatively, with no known complications. Pathologic analysis confirmed the en bloc removal of these lesions with negative margins.

CONCLUSIONS

We conclude that ARNV is an effective strategy for the precise, en bloc removal of spinal lesions including both sacrococcygeal tumors involving the retrorectal space and thoracic schwannomas.

Primary Bone Tumors of the Spine—Proposal for Treatment Based on a Single Centre Experience

This study reports a large single-center series of primary bone tumors of the spine (PBTs). We aimed to review the concepts for management, as this kind of tumor represents a very rare entity, and also propose a new treatment algorithm. Retrospective analysis revealed 92 patients receiving surgery for PBTs from 2007 to 2019 at our center. They were analyzed based on surgical management and the course of the disease. A total of 145 surgical procedures were performed (50 cervical, 46 thoracic, 28 lumbar, and 21 sacral). Complete tumor resection was achieved in 65%, of which 22% showed tumor recurrence during follow-up (mean time to recurrence 334 days). The five-year mortality rate was significantly lower after complete resection (3% versus 25% after subtotal resection). Most of the patients improved in their symptoms through surgery. Regarding the tumor entity, the most common PBTs were vertebral hemangiomas (20%), osteoid osteomas (15%), and chordomas (16%). The Enneking graduation system showed a good correlation with the risk of recurrence and mortality. Complete resection in PBTs increased survival rates and remains the method of choice. Thus, quality of life—especially with a higher extent of resection—should be considered.

Spinal Tumors: Diagnosis and Treatment

Tumors that present in or around the spine can be challenging to diagnose and treat. A proper workup involves a complete history and physical examination, appropriate staging studies, appropriate imaging of the entire spine, and a tissue biopsy. The biopsy defines the lesion and guides treatment, but in some rare instances, rapid neurological decline may lead to urgent or emergent surgery before it can be analyzed. "Enneking-appropriate" margins should remain the goal for primary tumors while adequate debulking/separation/stabilization are often the goals in metastatic disease. Primary tumors of the spine are rare and often complex tumors to operate on-achieving Enneking-appropriate margins provides the greatest chance of survival while decreasing the chance of local recurrence. Metastatic tumors of the spine are increasingly more common, and timing of surgery must be considered within the greater framework of the patient and the patient's disease, deficits, stability, and other treatments available. The specific tumor type will dictate what other multidisciplinary approaches are available, allowing for chemotherapy and radiation as needed.

Complications in spinal tumor surgery (review of literature)

Combined anterior and posterior approaches are required in spinal tumor surgery and considered highly invasive. Anatomical and physiological features of the surgical intervention area should be taken into consideration as well. Thus, these criteria reflect the severity of intraoperative complications during the surgical treatment of spinal tumors. The authors reviewed the scientific literature on the frequency and nature of complications in surgical interventions for spinal tumors.The most significant risk factors for intraoperative complications have been considered, the main of which are: the proximity of the location of the main vessels and viscera, the development of postoperative liquorrhea, as well as surgical site infection. Based on the studied information, we presented the methods of prevention and surgical tactics options in complications.

Construction, Validation, and Visualization of Two Web-Based Nomograms for Predicting Overall Survival and Cancer-Specific Survival in Elderly Patients with Primary Osseous Spinal Neoplasms

Background

Primary osseous spinal neoplasms (POSNs) are the rarest tumor type in the spine. Very few studies have presented data on elderly patients with POSNs specifically. The present study was aimed at exploring the prognostic factors and developing two web-based nomograms to predict overall survival (OS) and cancer-specific survival (CSS) for this population.

Method

The data of elderly patients with POSNs was extracted from the Surveillance, Epidemiology, and End Results (SEER) database between 2004 and 2015. Cox regression analyses were performed to determine independent prognostic factors for OS and CSS, these prognostic factors were incorporated to establish nomograms. The discrimination of the nomograms was evaluated by the receiver operating characteristic (ROC) curve and the value of area under the curve (AUC). Calibration curve was plotted to assess the predictive accuracy of model. Decision curve analysis (DCA) was conducted to determine the net clinical benefit. Furthermore, two web-based survival rate calculators were developed.

Result

A total of 430 patients were finally selected into this study and were randomly assigned to the training set (302 cases) and validation set (128 cases). Of these, 289 patients were further considered for the analysis of CSS and were randomized into training set (205 cases) and validation set (84 cases). Based on the results of univariate and multivariate Cox analyses, variables that significantly correlated with survival outcomes were used to establish nomograms for OS and CSS prediction. Two established nomograms demonstrated good predictive performance. In the training set, the AUCs of the nomogram for predicting 12-, 24-, and 36-month OS were 0.849, 0.903, and 0.889, respectively, and those for predicting 12-, 24-, and 36-month CSS were 0.890, 0.880, and 0.881, respectively. Two web-based survival rate calculators were developed to estimate OS (https://research1.shinyapps.io/DynNomappOS/) and CSS (https://research1.shinyapps.io/DynNomappCSS/).

Conclusion

Novel nomograms based on identified clinicopathological factors were developed and can be used as a tool for clinicians to predict OS and CSS in elderly patients with POSNs. These models could help facilitate a personalized survival evaluation for this population.

Integrated Custom Composite Polyetheretherketone/Carbon fiber (PEEK/CF) Vertebral Body Replacement (VBR) in the Treatment of Bone Tumors of the Spine: A Preliminary Report From a Multicenter Study

STUDY DESIGN

Retrospective, multicenter chart, and radiologic review.

OBJECTIVE

To present the first case series of bone tumors of the spine surgically reconstructed with a new custom, fully radiolucent, polyetheretherketone/carbon fiber (PEEK/CF) vertebral body replacement (VBR) integrated system.

SUMMARY OF BACKGROUND DATA

Surgical resections of spinal tumors result in large defects and local recurrence remains a concern. Current titanium-based implants adversely affects postoperative imaging, directly affects ability to identify tumor recurrence, and for delivery of radiotherapy treatments. PEEK/CF spinal implants allows for improved tumor surveillance, precise pre-radiation Computed Tomography planning, and reduces interference with post-reconstructive adjuvant radiotherapy.

METHOD

Thirteen patients with spinal tumors underwent vertebral body resection and reconstruction with an integrated, fully radiolucent, custom PEEK/CF vertebral body replacement, and radiolucent posterior PEEK/CF screw-rod system and/or radiolucent anterior PEEK/CF plate system. Clinical and radiographic data were tabulated. Need for adjuvant radiotherapy determined based on final tissue histology and extent of surgical margins. Postoperative surveillance imaging were reviewed for local tumor recurrence.

RESULTS

The ability to integrate the PEEK/CF VBR connected to either the posterior screw-rod system, or anterior plate system provided immediate stability. The VBR was placed directly on cancellous vertebral body surface in 46.2% of cases. Loosening of the distal, or proximal, aspect of posterior system was seen in 15.4% of cases. There was no clinical or radiographic evidence of VBR migration and subsidence at latest follow up. Local recurrence occurred in one (7.7%) patient.

CONCLUSION

This is the first series to describe the use of a fully-radiolucent, integrated, PEEK/CF implant system for spinal tumor reconstruction. The use of a PEEK/CF VBR system integrated to either the anterior plate, or posterior screw-rod system is feasible and allows for superior postoperative surveillance imaging and effective delivery of postoperative adjuvant radiotherapy.Level of Evidence: 4.

Video-Assisted Thoracoscopic En Bloc Vertebrectomy for Spine Tumors: Technique and Outcomes in a Series of 33 Patients

BACKGROUND

In en bloc vertebrectomy, the posterior approach is associated with limited access to anterior structures (vertebral body, esophagus, aorta, azygos vein). Video-assisted thoracoscopic surgery (VATS) might prove to be advantageous during thoracic en bloc vertebrectomy by allowing a combined anterior-posterior access in the prone position. We describe the technique and review the outcomes of 33 cases of video-assisted thoracoscopic en bloc vertebrectomy.

METHODS

A retrospective, single-center cohort study included all cases of VATS with a minimum follow-up of 1 year. A team of thoracic and orthopaedic surgeons performed the surgical procedure with the patient in a single, prone position. Anterior release was carried out thoracoscopically, followed by posterior en bloc tumor removal.

RESULTS

From 2003 to 2019, 33 patients were included. Nine patients underwent total vertebrectomy (8 had single-level and 1 had 3-level), and 24 patients underwent partial vertebrectomy (1 had single-level, 8 had 2-level, 13 had 3-level, and 2 had 4-level). Ten patients had pulmonary resection. Histology revealed 18 cases (55%) of primary bone tumors, 6 cases (18%) of lung cancer invading the spine, 6 cases (18%) of solitary metastasis, and 3 other cases (9%). The margins were tumor-free in 28 cases (85%). The median operative time was 240 minutes (range, 150 to 510 minutes), with a median blood loss of 1,200 mL (range, 400 to 6,700 mL), and there were 2 cases of conversion to thoracotomy. A total of 33 complications occurred in 18 patients (55%), and these were predominantly pulmonary. One death was surgery-related (infection). One patient had a persistent monoplegia. At a median follow-up of 63 months (range, 12 to 156 months), there were 21 surviving patients (64%) with 2 local recurrences and 1 distant recurrence, and 2 patients (6%) were lost to follow-up. The survival rates were 94% at 1 year, 71% at 2 years, and 68% at 5 years.

CONCLUSIONS

VATS en bloc vertebrectomy may be indicated for T2-to-T11 spine tumors with the exception of massive tumors, substantial chest wall and/or mediastinal invasion, and lung cancer exceeding 7 cm. The technique yielded satisfactory surgical and oncologic outcomes.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

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.

Prognostic Significance of Tumor-Associated Macrophages in Chondroblastoma and Their Association with Response to Adjuvant Radiotherapy

Objective

Chondroblastoma (CB) is a rare and locally growing cartilage-derived tumor. Currently, clinical implications of tumor-associated macrophages (TAMs) in CB remain unclear. In this study, we sought to analyze the relationship between TAM parameters (including densities of CD68+ and CD163+ cells as well as the CD163+/CD68+ ratio) and clinicopathological characteristics and survival of patients.

Methods

Immunohistochemistry was used to assess TAM subtypes for CD68 and CD163, as well as the expression levels of p53, CD34, and Ki-67 on tumor cells in 132 tissue specimens retrieved between July 2002 and April 2020. Then, TAM parameters were retrospectively analyzed for their associations with patient outcomes (local recurrence-free survival [LRFS] and overall survival [OS]) and clinicopathological features.

Results

TAM densities were significantly higher in axial chondroblastoma tissue than in extra-axial chondroblastoma tissue. Moreover, the number of CD163+ TAMs was positively correlated with tumor invasion of surrounding tissues and high expression of CD34 and Ki-67 on tumor cells, whereas CD163+ cell density and the CD163/CD68 ratio were negatively associated with patient response to adjuvant radiotherapy. Univariate Kaplan-Meier analysis revealed that the number of CD68+ and CD163+ lymphocytes was significantly associated with both LRFS and OS. Multivariate Cox regression analysis showed that CD163+ and CD68+ cell levels were independent prognostic factors of LRFS, while TAM data independently predicted OS. More importantly, in subgroup analysis based on three significant factors in univariate survival analysis (including tumor location, adjuvant radiotherapy, and surrounding tissue invasion by tumors), the TAM parameters still displayed good prognostic performance.

Conclusion

These data suggest that TAM may significantly affect the biological behavior of CB. We hypothesize that modulating the TAM level or polarization status in the microenvironment may be an effective approach for CB treatment.

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.

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.

The Clinical Characteristics and Prediction Nomograms for Primary Spine Malignancies

Background

Primary spine malignancies (PSMs) are relatively rare in bone tumors. Due to their rarity, the clinical characteristics and prognostic factors are still ambiguous. In this study, we aim to identify the clinical features and proposed prediction nomograms for patients with PSMs.

Methods

Patients diagnosed with PSMs including chordoma, osteosarcoma, chondrosarcoma, Ewing sarcoma, and malignant giant cell tumor of bone (GCTB) between 1975 and 2016 were selected from the Surveillance, Epidemiology, and End Results (SEER) database. The patient and tumor characteristics were described based on clinical information. The significant prognostic factors of overall survival (OS) and cancer-specific survival (CSS) were identified by the univariate and multivariate Cox analysis. Then, the nomograms for OS and CSS were established based on the selected predictors and their accuracy was explored by the Cox–Snell residual plot, area under the curve (AUC) of receiver operator characteristic (ROC) and calibration curve.

Results

The clinical information of 1,096 patients with PSMs was selected from the SEER database between 1975 and 2016. A total of 395 patients were identified with full survival and treatment data between 2004 and 2016. Chordoma is the commonest tumor with 400 cases, along 172 cases with osteosarcoma, 240 cases with chondrosarcoma, 262 cases with Ewing sarcoma and 22 cases with malignant GCTB. The univariate and multivariate analyses revealed that older age (Age > 60), distant metastasis, chemotherapy, and Surgery were independent predictors for OS and/or CSS. Based on these results, the nomograms were established with a better applicability (AUC for CSS: 0.784; AUC for OS: 0.780).

Conclusions

This study provides the statistics evidence for the clinical characteristics and predictors for patients with PSMs based on a large size population. Additionally, precise prediction nomograms were also established with a well-applicability.

Surgical treatment of primary mobile spine chordoma

BACKGROUND AND OBJECTIVES

Chordomas of the mobile spine (C1-L5) are rare malignant tumors. The purpose of this study was to review the outcome of surgical treatment for patients with primary mobile spine chordomas.

METHODS

The oncologic outcomes and survival of 26 patients undergoing surgical resection for a primary mobile spine chordoma were assessed over a 25-year period. The mean follow-up was 12 ± 6 years.

RESULTS

The 2-, 5-, and 10-year disease-free survivals were 95%, 61%, and 55%. The local recurrence-free survival was improved in patients receiving en bloc resection with negative margins (83% vs. 35%, p = 0.02) and similar in patients receiving adjuvant radiation therapy (43% vs. 45%, p = 0.30) at 10 years. Debulking of the tumor (hazard ratio [HR] = 6.41, p = 0.01) and a local recurrence (HR = 9.52, p = 0.005) were associated with death due to disease. Complications occurred in 19 (73%) patients, leading to reoperation in 9 (35%) patients; this rate was similar in intralesional and en bloc procedures.

CONCLUSION

Surgical resection of mobile spine chordomas is associated with a high rate of complications; however, en bloc resection can provide a hope for cure and appears to confer better oncologic outcomes for these tumors without an increase in complications compared to lesser resections.

Strategy for the Practice of Spine Oncological Surgery During the Covid-19 Pandemic

STUDY DESIGN

Case series.

OBJECTIVE

For each of the most frequent clinical scenarios, the authors reached a consensus on how should be timing and indications be optimized to reduce risk while maintaining the expected outcomes under the Covid-19 pandemics.

SUMMARY OF BACKGROUND DATA

The organization of health care has been changed by the Covid-19 pandemic with a direct impact on Spine Oncology Surgery. Emergency surgery is still a priority, but in case of spinal tumors it should be better defined which conditions require emergency treatment.

METHODS

An expert panel with general spine surgeons, oncological spine surgeons, and radiation oncologists was formed to analyze the most frequent scenarios in spinal musculoskeletal oncology during Covid-19 pandemics.

RESULTS

Spine metastases can be found incidentally during follow-up or can clinically occur by increasing pain, pathologic fracture, and/or neurological symptoms. Primary spine tumors are much more rare and very rarely present with acute onset. The first step is to suspect this rare condition, to avoid to treat a primary tumor as it were a metastasis. Most complex surgery, like en bloc resection, associated with high morbidity and mortality rate for the treatment of low grade malignancy like chordoma or chondrosarcomas, if intensive care unit availability is reduced, can be best delayed some weeks, as not impacting on prognosis, due to the slow growth rate of these conditions. The currently accepted protocols for Ewing sarcoma (ES) and osteogenic sarcoma must be performed for local and systemic disease control. For ES, after the first courses of chemotherapy, radiotherapy can be selected instead of surgery, during Covid-19, to the end of the full course of chemotherapy. In immunocompromised patients, (treated by chemotherapy), it is necessary to avoid contact with affected or exposed people.

CONCLUSION

Even more than during normal times, a multidisciplinary approach is mandatory to share the decision to modify a treatment strategy.

LEVEL OF EVIDENCE

5.

Function Preservation or Oncological Appropriateness in Spinal Bone Tumors?: A Case Series of Segmental Resection of the Spinal Canal Content (Spinal Amputation)

STUDY DESIGN

Retrospective review of prospectively collected data.

OBJECTIVE

To evaluate (1) if the segmental resection of the content of the spinal canal could provide an Enneking appropriate tumor-free margin for local control of primary bone tumors surrounding and invading the canal and (2) the safety profile of the segmental resection of the neurostructures.

SUMMARY OF BACKGROUND DATA

Treatment outcomes of primary malignant and benign aggressive bone tumors of the spine have been dramatically changed by the application of the musculoskeletal oncologic principles described by Enneking. However, the efficacy of spinal oncology surgery might be limited by unique features of spinal anatomy.

METHODS

Database search was conducted with the following inclusion criteria: en bloc resection, segmental inclusion of the spinal canal content in the surgical specimen, histologically proven diagnosis, minimum follow-up of 2 years. Exclusion criteria were piecemeal excision of the tumor (debulking) and diagnosis other than primary bone tumors (metastasis, or local extension of extraosseous tumors).

RESULTS

A consecutive cohort of eight patients (three men, five women) was available for review. Two patients died within 3 months from the surgery for systemic disease progression or sequelae of the surgery. En bloc resection with segmental spinal canal content inclusion was able to achieve local control of the disease in four out of remaining six cases (66.7%) at an average follow-up of 68.7 months (range 12-174 mo). Three patients in whom local control was achieved are free from disease at an average follow-up of 98.7 months (range 38-174), and one died for systemic disease progression (after 38 mo). Seven out of 8 patients (87.5%) experienced overall 16 complications.

CONCLUSION

En bloc resection including the spinal canal content (spinal amputation) to achieve a tumor-free margin might be considered to perform an Enneking appropriate treatment for motivated patients.

LEVEL OF EVIDENCE

4.

The Relationship Between Tumor-Stroma Ratio, the Immune Microenvironment, and Survival in Patients With Spinal Chordoma

BACKGROUND

Currently, little is known about the clinical relevance of tumor-stroma ratio (TSR) in chordoma and data discussing the relationship between TSR and immune status of chordoma are lacking.

OBJECTIVE

To characterize TSR distribution in spinal chordoma, and investigated its correlation with clinicopathologic or immunological features of patients and outcome.

METHODS

TSR was assessed visually on hematoxylin and eosin-stained sections from 54 tumor specimens by 2 independent pathologists. Multiplex immunofluorescence was used to quantify the expression levels of microvessel density, Ki-67, Brachyury, and tumor as well as stromal PD-L1. Tumor immunity status including the Immunoscore and densities of tumor-infiltrating lymphocytes (TILs) subtypes were obtained from our published data and reanalyzed.

RESULTS

Bland-Altman plot showed no difference between mean TSR derived from the two observers. TSR was positively associated with stromal PD-L1 expression, the Immunoscore and CD3+ as well as CD4+ TILs density, but negatively correlated with tumor microvessel density, Ki-67 index, surrounding muscle invasion by tumor and number of Foxp3+ and PD-1+ TILs. Low TSR independently predicted poor local recurrence-free survival and overall survival. Moreover, patients with low TSR and low Immunoscore chordoma phenotype were associated with the worst survival. More importantly, combined TSR and Immunoscore accurately reflected prognosis and enhanced the ability of TSR or Immunoscore alone for outcome prediction.

CONCLUSION

These data reveal the significant impact of TSR on tumor progression and immunological response of patients. Subsequent use of agents targeting the stroma compartment may be an effective strategy to treat chordoma especially in combination with immune-based drugs.

Clinical Impact of the Immune Microenvironment in Spinal Chordoma: Immunoscore as an Independent Favorable Prognostic Factor

BACKGROUND

Currently, clinical implications of immune system cells in chordoma remain to be elucidated.

OBJECTIVE

To characterize in situ immune cell infiltrates, the Immunoscore, and investigate their correlation with clinicopathologic data of spinal chordoma patients and outcome.

METHODS

Tumor-infiltrating lymphocytes (TILs) subtypes were assessed in 54 tumor specimens using immunohistochemistry for CD3, CD4, CD8, CD20, Foxp3, PD-1, and PD-L1.

RESULTS

Overall, immune cell infiltrates were present in all samples and there was low or moderate correlation among several TILs subsets. PD-1+ TILs density, CD3+, and CD8+ TILs densities in the tumor interior (TI) subarea were associated with surrounding muscle invasion by tumor, whereas PD-L1+ TILs showed inverse association with tumor pathological grade and stage. The density of PD-1+ TILs, PD-L1+ TILs, CD4+ TILs, and CD3+ TILs both in the TI and combined tumor regions (TI and invasion margin) were significantly associated with local recurrence-free survival and overall survival (OS). However, Foxp3+ TILs (P = .024) and CD8+ TILs evaluated in the TI (P < .001) only correlated with OS. The Immunoscore predicted less aggressive clinical features and favorable outcomes. Patients with an Immunoscore of 4 had a median OS of 128 mo, while I0 (Immunoscore of 0) patients survived only 27 mo. Multivariate analysis demonstrated that the Immunoscore was an independent favorable prognostic factor of both local recurrence-free survival (P = .026) and OS (P = .046).

CONCLUSION

Our data suggest a clinically relevant role of the immune microenvironment in spinal chordoma and identify the Immunoscore as promising prognostic marker.

Revision surgery for tumors of the thoracic and lumbar spine: causes, prevention, and treatment strategy

INTRODUCTION

Revision surgery in spine tumor surgery can offer peculiar challenges given the severity of the majority of these lesions and the complexity of surgical procedures that are required.

MATERIALS AND METHODS AND RESULTS

Based on literature review and on personal experience, surgical site infection, cerebrospinal fluid leakage, tumor recurrence and hardware failures are some of the possible causes of surgical revision in this set of patients.

CONCLUSIONS

The aim of this study is to evaluate the most frequent complications that can lead to revision in spine tumor patients, to provide suggestions on how to prevent these events and to offer reasonable strategies to properly plan and perform a revision surgery. These slides can be retrieved under Electronic Supplementary Material.

Surgical Strategies for Chordoma

Chordomas are rare tumors of the axial skeleton whose slow growth belies a relentless tumor with a propensity for recurrence and late metastasis. Local control remains an issue with chordoma in spite of aggressive operative management. High local failure rates have led to the exploration of alternative methods of treatment. Radiation continues to gain acceptance as an adjuvant to surgery and, in some cases, as a standalone treatment. However, the use of radiation remains controversial, and operative management remains the standard of care in spite of relatively high morbidity.

Perioperative adverse events following surgery for primary bone tumors of the spine and en bloc resection for metastases

OBJECTIVE

Surgical treatment of primary bone tumors of the spine and en bloc resection for isolated metastases are complex and challenging. Operative care is fraught with complications, though the true incidence and predictors of adverse events (AEs), length of stay (LOS), and mortality in this population remain poorly understood. The primary objective of this study was to describe the incidence and predictors of perioperative AEs in these patients. Secondary objectives included the determination of the incidence and predictors of admission to the intensive care unit (ICU), unanticipated reoperation during the same admission, hospital LOS, and mortality.

METHODS

In this retrospective analysis of prospectively collected data, the authors included consecutive patients at a single quaternary care referral center (January 1, 2009, to September 30, 2018) who underwent either surgery for a primary bone tumor of the spine or an en bloc resection for an isolated spinal metastasis. Information on perioperative AEs, demographic data, primary tumor histology, neurological status, surgical variables, pathological margins, Enneking appropriateness, LOS, ICU stay, reoperation during the same admission period, and in-hospital mortality was collected prospectively in the institutional database. The modified frailty score was extracted retrospectively.

RESULTS

One hundred thirteen patients met the inclusion criteria: 98 with primary bone tumors and 15 with isolated metastases. The cohort was 59% male, and the mean age was 49 years (SD 19 years). Overall, 79% of the patients experienced at least 1 AE. The median number of AEs per patient was 2 (IQR 0-4 AEs), and the median LOS was 16 days (IQR 9-32 days). No in-hospital deaths occurred in the cohort. Thirty-two patients (28%) required an ICU stay and 19% underwent an unanticipated second surgery during their admission. A longer surgical duration was associated with a higher likelihood of AEs (OR 1.21/hour, 95% CI 1.06-1.37, p = 0.005), longer ICU stay (OR 1.35/hour, 95% CI 1 1.20-1.52, p < 0.001), and reoperation (OR 1.001/hour, 95% CI 1.0003-1.003, p = 0.012). Longer hospital LOS was independently predicted by older age, female sex, upper cervical and sacral location of the tumor, surgical duration, preoperative neurological deficit, presence of AEs, and higher modified frailty index score.

CONCLUSIONS

Surgeries for primary bone tumors and en bloc resection for metastatic tumors are associated with a high incidence of perioperative AEs. Surgical duration predicts complications, reoperation, LOS, and ICU stay.

Multilevel Pedicular Osteotomies for En Bloc Resection of a Primary Ewing Sarcoma of the Subaxial Cervical Spine with Pedicle Screw Reconstruction

BACKGROUND

Primary Ewing sarcoma of the mobile spine is a rare disease. Its management requires careful surgical planning, because radical, margin-free excision is directly correlated with prognosis. Extensive bone removal in the cervical spine can lead to instability and cause postoperative iatrogenic cervical deformity. Thus, spinal instrumentation plays an important role in restoring postresection spinal stability and improving quality of life.

METHODS

We present a novel technique that allows successful removal of a large Ewing sarcoma of the subaxial cervical spine, infiltrating and traversing the posterior bone elements, and extending into the paraspinal muscles. This technique involves radical en bloc resection of posteriorly located cervical tumors via multilevel pediculotomy, with terminal vertebrae pedicle screw reconstruction.

RESULTS

Terminal vertebrae cervical pedicle screw reconstruction allowed wide surgical excision with satisfactory oncologic and mechanical results.

CONCLUSIONS

This technique enables 1-stage total tumor resection and stabilization and may be a viable alternative to radical en bloc resection of posteriorly located epidural malignant lesions of the cervical spine in selected cases.

All-posterior total en bloc spondylectomy for thoracic spinal tumors

Total en bloc spondylectomy (TES) involves disruption of the bony neural ring via bilateral pediculotomy and posterior en bloc laminectomy followed by the en bloc vertebrectomy. All-posterior TES allows for resection of malignant and benign aggressive spine tumors with minimal morbidity. The purpose of this report is to describe two cases of all-posterior spondylectomy using the recently developed Resegone retractor (K2M, Leesburg, VA, USA) which facilitates an all-posterior resection. The technique is well described and generally includes 3 major portions: a resection of the posterior elements with bilateral costotransversectomy, passage of threadwire saws anterior to the vertebral bodies, and en bloc resection of the anterior column. With the device in place, the sawing of the bone can be performed without risking pull-through into the cord, while cutting through the desired path in a smooth and parallel fashion.

Changes to the American Joint Committee on Cancer staging system for spine tumors-practice update

The American Joint Committee on Cancer recently released the 8th edition staging manual; this provides the staging system used at nearly all American cancer centers and many international centers. For the first time, this system separates out spine and pelvic tumors with a separate and distinct TNM classification. This practice update reviews these changes along with the rationale and data behind this change.

Successful total en bloc spondylectomy of the L3 vertebra with a paravertebral giant cell tumor following preoperative treatment with denosumab: a case report

BACKGROUND

Giant cell tumor is known to be a benign neoplasm that arises most commonly in the long bones, while cases in the spine are rare. Recently, denosumab, a monoclonal antibody that inhibits receptor activator of nuclear factor-kappa β ligand, has been used to treat patients with giant cell tumor. However, there are few reports of total en bloc spondylectomy being used for paravertebral giant cell tumor lesions following denosumab therapy.

CASE PRESENTATION

Our patient was a 20-year-old Japanese woman with a 4-month history of lower back pain. A spinal computed tomography scan and magnetic resonance imaging of her lumbar spine revealed an osteolytic lesion involving the L3 vertebral body, and the tumor extended toward the left side of the paravertebral soft tissue and into the left pedicle. The lesion was diagnosed as a giant cell tumor by needle biopsy. Denosumab treatment calcified the paravertebral giant cell tumor lesion and the tumor vertebral body was removed completely by total en bloc spondylectomy.

CONCLUSION

This case report describes a patient with a paravertebral giant cell tumor who was successfully treated by preoperative denosumab injection followed by total en bloc spondylectomy.

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.

Ewing Sarcoma of the Spine: Prognostic Variables for Survival and Local Control in Surgically Treated Patients

STUDY DESIGN

Multicenter, ambispective observational study.

OBJECTIVE

To quantify mortality and local recurrence after surgical treatment of spinal Ewing sarcoma (ES) and to determine whether an Enneking appropriate procedure and surgical margins (en bloc resection with wide/marginal margins) are associated with improved prognosis.

SUMMARY OF BACKGROUND DATA

Treatment of primary ES of the spine is complex. Ambiguity remains regarding the role and optimal type of surgery in the treatment of spinal ES.

METHODS

The AOSpine Knowledge Forum Tumor developed a multicenter database including demographics, diagnosis, treatment, mortality, and recurrence rate data for spinal ES. Patients were stratified based on surgical margins and Enneking appropriateness. Survival and recurrence were analyzed using Kaplan-Meier curves and log-rank tests.

RESULTS

Fifty-eight patients diagnosed with primary spinal ES underwent surgery. Enneking appropriateness of surgery was known for 55 patients; 24 (44%) treated Enneking appropriately (EA) and 31 (56%) treated Enneking inappropriately (EI). A statistically significant difference in favor of EA-treated patients was found with regards to survival (P = 0.034). Neoadjuvant and postoperative chemotherapy was significantly associated with increased survival (P = 0.008). Local recurrence occurred in 22% (N = 5) of patients with an EA procedure versus 38% (N = 11) of patients with an EI procedure. The timing of chemotherapy treatment was significantly different between the Enneking cohorts (P < 0.001) and all EA-treated patients received chemotherapy treatment. Although, local recurrence was not significantly different between Enneking cohorts (P = 0.140), intralesional surgical margins and patients who received a previous spine tumor operation were associated with increased local recurrence (P = 0.025 and P = 0.018, respectively).

CONCLUSION

Surgery should be undertaken when an en bloc resection with wide/marginal margins is feasible. An EA surgery correlates with improved survival, but the impact of other prognostic factors needs to be evaluated. En bloc resection with wide/marginal margins is associated with local control.

LEVEL OF EVIDENCE

3.

Clinicopathologic implications of CD8+/Foxp3+ ratio and miR-574-3p/PD-L1 axis in spinal chordoma patients

Currently, little is known about the interactions between microRNAs (miRNAs) and the PD-1/PD-L1 signaling pathway in chordoma, and data discussing the role of the immune milieu in chordoma prognosis are limited. We aimed to analyze the relationship between PD-L1, miR-574-3p, microenvironmental tumor-infiltrating lymphocytes (TILs) and clinicopathological features of spinal chordoma patients. PD-L1 expression and TILs (including Foxp3+, CD8+, PD-1+ and PD-L1+) were assessed by immunohistochemistry in tumor specimens of 54 spinal chordoma patients. MiRNAs microarray and bioinformatical analysis were used to identify miRNAs potentially regulating PD-L1 expression, which were further validated by quantitative RT-PCR. miR-574-3p was identified to potentially regulate PD-L1 expression in chordoma, which inversely correlated with PD-L1. Positive PD-L1 expression on tumor cells was associated with advanced stages (P = 0.041) and TILs infiltration (P = 0.005), whereas decreased miR-574-3p level correlated with higher muscle invasion (P = 0.012), more severe tumor necrosis (P = 0.022) and poor patient survival. Importantly, a patient subgroup with PD-L1+/miR-574-3plow chordoma phenotype was significantly associated with worse local recurrence-free survival (LRFS) (P = 0.026). PD-1+ TILs density was associated with surrounding muscle invasion (P = 0.014), and independently portended poor LRFS (P = 0.040), while PD-L1+ TILs showed tendencies of less aggressive clinical outcomes. Multivariate analysis of OS only found CD8+/Foxp3+ ratio to be independent prognostic factor (P = 0.022). These findings may be useful to stratify patients into prognostic groups and provide a rationale for the use of checkpoint blockade therapy, possibly by administering miR-574-3p mimics, in spinal chordoma.

High expression of Sam68 in sacral chordomas is associated with worse clinical outcomes

Src-associated in mitosis of 68 kDa (Sam68), also known as KHDRBS1 (KH domain-containing, RNA-binding, signal transduction-associated 1), is a member of the signal transduction and activation of RNA family. Previous studies have demonstrated that the aberrant expression of Sam68 is associated with the progression and prognosis of a variety of cancers, but little is known about its expression and role in chordomas, which are rare and aggressive bone neoplasms. In this study, we analyzed 40 tumor tissues and 20 distant normal tissues obtained from 40 patients with sacral chordoma using immunohistochemistry, and observed the expression of Sam68 was significantly upregulated in sacral chordomas compared with normal tissues (P=0.001). A positive correlation between the expression of Sam68 and the cell proliferation index Ki-67 was determined using Spearman’s rank correlation test (γ =0.599, P<0.001). In addition, high expression of Sam68 was significantly associated with surrounding muscle invasion (P<0.001). Moreover, Kaplan–Meier curves showed that patients with overexpressed Sam68 had shorter local recurrence-free survival time (P<0.001). Lastly, multivariate analysis indicated that Sam68 is an independent prognostic factor for the local recurrence-free survival of sacral chordomas (hazard ratio =5.929, 95% CI: 1.092–32.188, P=0.039). Our findings suggest the use of Sam68 as a predictor for the recurrence of sacral chordomas.

En Bloc Resection Versus Intralesional Surgery in the Treatment of Giant Cell Tumor of the Spine

STUDY DESIGN

Multicenter, ambispective observational study.

OBJECTIVE

The aim of this study was to quantify local recurrence (LR) and mortality rates after surgical treatment of spinal giant cell tumor and to determine whether en bloc resection with wide/marginal margins is associated with improved prognosis compared to an intralesional procedure.

SUMMARY OF BACKGROUND DATA

Giant cell tumor (GCT) of the spine is a rare primary bone tumor known for its local aggressiveness. Optimal surgical treatment remains to be determined.

METHODS

The AOSpine Knowledge Forum Tumor developed a comprehensive multicenter database including demographics, presentation, diagnosis, treatment, mortality, and recurrence rate data for GCT of the spine. Patients were analyzed based on surgical margins, including Enneking appropriateness.

RESULTS

Between 1991 and 2011, 82 patients underwent surgery for spinal GCT. According to the Enneking classification, 59 (74%) tumors were classified as S3-aggressive and 21 (26%) as S2-active. The surgical margins were wide/marginal in 27 (36%) patients and intralesional in 48 (64%) patients. Thirty-nine of 77 (51%) underwent Enneking appropriate (EA) treatment and 38 (49%) underwent Enneking inappropriate (EI) treatment. Eighteen (22%) patients experienced LR. LR occurred in 11 (29%) EI-treated patients and six (15%) EA-treated patients (P = 0.151). There was a significant difference between wide/marginal margins and intralesional margins for LR (P = 0.029). Seven (9%) patients died. LR is strongly associated with death (Relative Risk 8.9, P < 0.001). Six (16%) EI-treated patients and one (3%) EA-treated patients died (P = 0.056). With regards to surgical margins, all patients who died underwent intralesional resection (P = 0.096).

CONCLUSION

En bloc resection with wide/marginal margins should be performed when technically feasible because it is associated with decreased LR. Intralesional resection is associated with increased LR, and mortality correlates with LR.

LEVEL OF EVIDENCE

3.

Expression of far upstream element-binding protein 1 correlates with c-Myc expression in sacral chordomas and is associated with tumor progression and poor prognosis

The far upstream element (FUSE)-binding protein 1 (FUBP1), a well-known transcriptional regulator of the proto-oncogene c-Myc, has been demonstrated by previous work to be aberrantly expressed in a variety of tumors and plays a critical role in tumor progression; however, its expression and function in relatively rare and aggressive chordomas remains unclear. In this retrospective study, we reviewed clinicopathologic characteristics of 40 patients diagnosed with sacral chordoma, and analyzed 40 tumor and 20 distant normal tissues obtained from patients during the primary surgical tumor excision. Using immunohistochemistry, we observed an up-regulation in the expression of FUBP1 and c-Myc in sacral chordomas compared with the normal tissues (P = 0.001 for both). Additionally, positive correlations of FUBP1 expression with c-Myc (γ = 0.651, P < 0.001) and the cell proliferation index Ki-67 expression (γ = 0.447, P = 0.004) were indicated using Spearman's rank correlation coefficient. Increased expression of FUBP1 was significantly associated with tumor invasion into the surrounding muscles (P = 0.002). Kaplan-Meier curves demonstrated the association between FUBP1 levels and the patients' local recurrence-free survival (LRFS) (P < 0.001) but not with the overall survival (OS) (P = 0.070). The independent prognostic significance of FUBP1 levels for the LRFS was indicated by multivariate analysis (HR = 4.272; 95% CI, 1.133-16.112; P = 0.032). Our findings demonstrate an association between FUBP1 levels and chordoma progression and prognosis, suggesting that FUBP1 can be used as a biomarker and a potential therapeutic target.

Total en bloc spondylectomy of the eleventh thoracic vertebra following denosumab therapy for the treatment of a giant cell tumor

Although denosumab has been reported to induce effective clinical results with respect to tumor shrinkage in a short-term follow-up clinical study, total spondylectomy is recognized as the treatment of choice for eradicating giant cell tumors (GCTs) of the spine. The present study reports the case involving a GCT in the 11th thoracic vertebra complicated by idiopathic scoliosis and treated using total en bloc spondylectomy (TES) with preoperative denosumab therapy. A 35-year-old woman received preoperative denosumab therapy for 8 months, followed by surgery using a computed tomography (CT)-based navigation system that optimized accuracy by recognizing the area of the detached parietal pleura, the irregular border of the collapsed vertebra, and the adjacent vertebra. Complete en bloc resection of the vertebra could be performed, suggesting denosumab can be an effective adjuvant therapy which can reduce the complexity of TES and CT-navigation system facilitated the safe use of this surgical method in a patient with idiopathic scoliosis.