Sustained long-term complete regression of a giant cell tumor of the spine after treatment with denosumab

Do Unresectable Giant Cell Tumors of Bone Treated With Denosumab Progress After Discontinuation of Treatment?

BACKGROUND

Denosumab represents a valuable treatment option for unresectable giant cell tumors of the bone (GCTBs). However, no standardized protocols exist determining the length of administration, with few studies having been published on patients who reached the end of treatment.

AIMS

To analyze the outcomes of patients diagnosed with GCTB and who had finished single treatment with denosumab.

METHODS AND RESULTS

This is a multicenter, retrospective, descriptive study carried out in seven Spanish hospitals with multidisciplinary sarcoma and musculoskeletal tumor boards, between 2009 and 2019. Sixteen patients diagnosed with unresectable GCTBs and treated with denosumab who had reached the end of their treatment were recruited for the study and had been followed up for a minimum of 2 years. Fifty percent of patients discontinued denosumab after showing signs of tumor control. The disease remained stable in 69% of patients (n = 11), with a median recurrence-free survival time of 46 months (20-157 months) after being treated for a median period of 19 months (5-83 months). Four patients experienced local progression, and one presented multifocal progression. These five patients were treated for a median period of 46 months (14-76 months), with a median recurrence-free survival time of 9 months (5-25 months).

CONCLUSION

The findings of the present study suggest that discontinuation of denosumab in patients with unresectable GCTB is not necessarily associated with the progression of the disease. Further research is needed to determine how long denosumab should be administered to minimize the risk of recurrence.

Giant cell tumor of the cervical spine: A very uncommon cause for cervical spine compression

Giant cell tumors (GCTs) are rare neoplasms, primarily found in long bones, typically affecting the epiphysis of the distal femur, proximal tibia, and distal radius. However, their occurrence in the cervical spine is exceedingly rare. Here, we present a case report of a 21-year-old female patient who presented with progressive neck pain, radiating numbness, and right hemiparesis. Radiographic imaging revealed a lytic lesion in the C3 vertebral body, further characterized by magnetic resonance imaging (MRI) and computed tomography (CT) scans. The patient underwent surgery for stabilization of the cervico-occipital hinge, decompression, and biopsy. Histopathological examination confirmed the diagnosis of a giant cell tumor. Postoperatively, the patient showed improvement in motor impairment, cervical pain, and numbness. She was proposed for adjuvant treatment based on Denosumab. However, she returned 1 month after surgery with worsened motor deficit, developing tetraparesis. Control MRI revealed a tumor flare-up. The decision was made not to reoperate on the patient and to accelerate the administration of Denosumab. Meanwhile, she experienced a pulmonary embolism leading to her demise. This case underscores the importance of considering giant cell tumors in the differential diagnosis of cervical spine lesions and emphasizes the successful and prompt management through a multidisciplinary approach involving surgical intervention and adjuvant therapy.

The risk of neurological deterioration while using neoadjuvant denosumab on patients with giant cell tumor of the spine presenting with epidural disease: a meta-analysis of the literature

BACKGROUND CONTEXT

Giant cell tumor (GCT) of bone is most commonly a benign but locally aggressive primary bone tumor. Spinal GCTs account for 2.7% to 6.5% of all GCTs in bone. En bloc resection, which is the preferred treatment for GCT of the spine, may not always be feasible due to the location, extent of the tumor, and/or the patient's comorbidities. Neoadjuvant denosumab has recently been shown to be effective in downstaging GCT, decreasing the size and extent of GCTs. However, the risk of neurologic deterioration is of major concern for patients with epidural spinal cord compression due to spinal GCT. We experienced this concern when a patient presented to our institution with a midthoracic spinal GCT with progressive epidural disease. The patient was not a good surgical candidate due to severe cardiac disease and uncontrolled diabetes. In considering nonoperative management for this patient, we asked ourselves the following question: What is the risk that this patient will develop neurologic deterioration if we do not urgently operate and opt to treat him with denosumab instead?

PURPOSE

The purpose of this study was to assess the literature to (1) determine the risk of neurological deterioration in patients receiving neoadjuvant denosumab for the treatment of spinal GCT and (2) to evaluate the secondary outcomes including radiographic features, surgical/technical complexity, and histological features after treatment.

STUDY DESIGN/SETTING

Meta-analysis of the literature.

PATIENT SAMPLE

Surgical cases of spinal GCT that (1) presented with type III Campanacci lesions, (2) had epidural disease classified as Bilsky type 1B or above and (3) received neoadjuvant denosumab therapy.

OUTCOME MEASURES

The primary outcome measure of interest was neurologic status during denosumab treatment. Secondary outcome measures of interest included radiographic features, surgical/technical complexity, histological features, tumor recurrence, and metastasis.

METHODS

Using predetermined inclusion and exclusion criteria, PubMed and Embase electronic databases were searched in August 2022 for articles reporting spinal GCTs treated with neoadjuvant denosumab and surgery. Keywords used were "Spine" AND "Giant Cell Tumor" AND "Denosumab."

RESULTS

A total of 428 articles were identified and screened. A total of 22 patients from 12 studies were included for review. 17 patients were female (17/22, 77%), mean age was 32 years (18-62 years) and average follow-up was 21 months. Most GCTs occurred in the thoracic and thoracolumbar spine (11 patients, 50%), followed by 36% in the lumbar spine and 14% in the cervical spine. Almost half of the patients had neurological deficits at presentation (10/22 patients, 45%), and more than 60% had Bilsky 2 or 3 epidural spinal cord compression. None of the patients deteriorated neurologically, irrespective of their neurological status at presentation (p-value=.02, CI -2.58 to -0.18). There were no local recurrences reported. One patient was found to have lung nodules postoperatively. More than 90% of cases had decreased overall tumor size and increased bone formation. Surgical dissection was facilitated in more than 85% of those who had documented surgical procedures. Four patients (18%) underwent initial spinal stabilization followed by neoadjuvant denosumab and then surgical excision of the GCT. Regarding the histologic analyses, denosumab eradicated the giant cells in 95% of cases. However, residual Receptor Activator of Nuclear Factor Kappa B Ligand (RANKL)-positive stromal cells were noted, in 27% (6 cases).

CONCLUSIONS

Neoadjuvant denosumab was a safe and effective means of treating spinal GCTs prior to surgery. Neurologic status remained stable or improved in all cases included in our review, irrespective of the presenting neurologic status. The most appropriate dosage and duration of denosumab therapy is yet to be determined. We recommend future well-designed studies to further evaluate the use of neoadjuvant denosumab for patients with spinal GCT.

Denosumab salvage therapy in an 11-year-old boy with locally recurrent unresectable giant cell tumor of the lumbar spine after surgery

Giant cell tumors (GCTs) of the bone are locally aggressive primary bone tumors with a benign character. Spinal involvement is rare which accounts for approximately 5% of all primary bone tumors and it is quite rare in the lumbar spine. An 11-year-old boy patient presented with pain of low back and bilateral low extremities. Lumbar CT and MRI revealed a lytic lesion of the L4 vertebra corpus. The patient earned remarkable and timely recovery with 2 surgical interventions and the use of denosumab. Surgical resection for GCTs is still preferable as the initial treatment, denosumab should be utilized after tumor resection whether based on the purpose of prevention or treatment of tumor recurrence.

Imaging Features of Aggressive Giant Cell Tumors of the Mobile Spine: Retrospective Analysis of 101 Patients From Single Center

STUDY DESIGN

Retrospective study.

OBJECTIVES

Giant cell tumors (GCTs) of the mobile spine can be locally aggressive. This study described and classified the typical and atypical appearance of aggressive spinal GCTs according to imaging findings to help the imaging diagnosis, especially for patients with rapid neurological deficit that may require emergent surgery without biopsy.

METHODS

Computed tomography (CT) and magnetic resonance imaging (MRI) scans of patients diagnosed with aggressive spinal GCTs at single center were reviewed.

RESULTS

Overall, 101 patients with 100 CT images and 94 MR images were examined. All lesions were osteolytic with cortical destruction; 95 lesions showed epidural extension; 90 were centered in the vertebral body; 82 showed pathological fracture and/or collapse of the vertebral body; 78 had pseudotrabeculation on CT; 80 showed low-to-iso signal intensity or heterogeneous high-signal intensity with cystic areas on the T2-weighted images; 9 showed fluid-fluid level on T2-weighted images; and 61 patients showed marked enhancement on contrast-enhanced CT and/or MRI. Forty-one lesions (40.6%) had at least 1 atypical radiographic feature: 19 involved ≥2 segments; 11 were centered in the posterior neural arch; 10 had a paravertebral mass over 2 segments; 16 showed partial margin sclerosis with partial cortical destruction on CT scans; and 3 showed mineralization within the tumor on CT. Eighty-eight patients underwent CT-guided biopsy with a diagnostic accuracy rate of 94.3%.

CONCLUSIONS

Spinal GCTs might appear more radiologically atypical, and about 40% of the lesions may have at least 1 atypical feature. CT-guided biopsies are recommended for definitive diagnosis.

Multimodal Management of Combined Posterior and Anterior Surgical Approach and Postoperative Pharmacological Therapy for Giant Cell Tumor of the Cervical Spine Encasing the Vertebral Artery: A Technical Case Report

Giant cell tumor (GCT) of bone is essentially benign but locally aggressive, and the rate of local recurrence is high when the resection is not enough. En bloc resection is recommended as an ideal solution for GCT to decrease the risk of local recurrence, but it remains challenging for cervical GCT. In this technical case report, we present a case of extensively infiltrating GCT of the cervical spine completely encasing the vertebral artery (VA) on one side. The tumor was distributed to layers A-D, sectors 3-8 based on the Weinstein-Boriani-Biagini staging. Combined posterior and anterior surgical approach for the cervical spine was successfully performed and followed by postoperative adjuvant pharmacological therapy. This kind of multimodal management may be one of the solutions for advanced cervical GCT.

Comprehensive treatment outcomes of giant cell tumor of the spine: A retrospective study

There is no consensus on a treatment strategy for spinal giant cell tumor of bone (GCTB) because of the difficulty in their treatment. Treatment options often include the use of the controversial denosumab, an antibody therapy aimed at tumor shrinkage, different curettage techniques, resection, or a combination of these therapies. The current study aimed to identify treatment methods associated with favorable outcomes in patients with spinal GCTB. We retrospectively reviewed 5 patients with spinal GCTB, including patients with tumors of the sacrum, treated at our hospital between September 2011 and November 2020. Two men and 3 women were included in the study. The median follow-up period was 74 months (range: 14-108 months). We surveyed the tumor site, treatment method, denosumab use, and outcomes. The median age was 17 years (range: 17-42 years). There were 2 cases of sacral GCTB and 1 case each of lumbar, cervical, and thoracic vertebral GCTB. The comorbidities observed included hepatitis, malignant lymphoma, atopic dermatitis, and asthma. The treatment method included zoledronic acid after embolization and denosumab, denosumab only, curettage and posterior fusion, and curettage resection after embolization and anterior and posterior fusion. Denosumab was used in all cases. Three patients were continuously disease-free, 1 patient with no evidence of disease, and 1 patient alive with disease. Aggressive treatment, especially surgical treatment, may lead to good results in spinal GCTB.

Unresectable Clival Giant Cell Tumor, Tumor Control With Denosumab After Relapse: A Case Report and Systematic Review of the Literature

Giant cell tumors (GCTs) of the skull base are rare entities. Although considered histologically benign, GCTs are locally aggressive with a high rate of local recurrence. The present case describes a 14-year-old girl with a clival GCT who underwent long-term therapy with denosumab after local relapse. To our knowledge, it is the second case described with a follow-up term >2 years from the start of denosumab and who did not receive any other adjuvant treatment besides denosumab. The patient achieved a local control of the disease. According to the few available data, radical excision with adjuvant therapy helps in long-term control in uncommon sites, such as the skull. However, the definitive treatment is still controversial because of their rarity and few follow-up data. The present case highlights the benefit of denosumab and its safety as long-term therapy and contributes to the existing literature with analysis and evaluation of the management strategies and prognosis.

Denosumab in Giant Cell Tumor of Bone: Multidisciplinary Medical Management Based on Pathophysiological Mechanisms and Real-World Evidence

Simple Summary

The widely accepted local therapy in extremity giant cell tumor of bone (GCTB) is surgery, in the form of extended intralesional curettage with adequate disease clearance and retention of the limb, wherever possible. Denosumab is a relevant therapy option for advanced GCTB, to benefit tumor response and surgical down-staging. Most GCTB patients with localized disease can be successfully treated with surgical curettage; patients with primary unresectable lesions or metastases may experience long-term clinical and radiological remission and pain control with denosumab treatment, and in this clinical situation, denosumab is currently the treatment of choice.

Abstract

(1) Despite the benign nature of the giant cell tumor of bone (GCTB), it shows a local recurrence rate of up to 50% and a chance of malignant transformation. The widely accepted local therapy in extremity GCTB is surgery, in the form of extended intralesional curettage with adequate disease clearance and retention of the limb, wherever possible. Denosumab, a human monoclonal antibody directed against the RANKL and associated inhibition of the RANKL pathway, is a relevant therapy option for advanced GCTB, to benefit tumor response and surgical down-staging. (2) The literature review of patients with GCTB treated with denosumab is performed via PubMed, using suitable keywords from January 2009 to January 2021. (3) Current indications for denosumab use are not definitively clear and unambiguous. Most GCTB patients with localized disease can be successfully treated with surgical curettage, and the role of denosumab in preoperative therapy in this patient population remains unclear. (4) However, patients with primary unresectable lesions or metastases may experience long-term clinical and radiological remission and pain control with denosumab treatment, and in this clinical situation, denosumab is currently the treatment of choice.

Total neurological recovery after surgical decompression and treatment with denosumab of large unresectable spinal giant cell tumour expanding to mediastinum

There is a controversy over the medical treatment of unresectable spinal giant cell tumour (GCT) regarding dosing and duration. We studied a spinal GCT case that had expanded to the thoracic spinal canal and mediastinum and was successfully treated by surgical decompression and denosumab. A woman in her 30s presented with weakness in both the lower extremities. MRI revealed a large tumour in the posterior mediastinum expanding from the thoracic vertebrae (T3–6), which compressed the spinal cord. The patient underwent urgent spinal decompression with instrumentation and her tissue was sent for a pathology study. Histologically and immunohistochemistry confirmed the diagnosis of GCT. Since it was an unresectable tumour, this patient was treated with denosumab. Her neurological problem resolved after 6 months of treatment. After 4 years of follow-up, the patient displayed no further progression and no side effects from long-term denosumab usage.

Diagnosis and Treatment of Lumbar Giant Cell Tumor of the Spine: Update on Current Management Strategies

(1) Background: Giant Cell Tumor of the spine remains a difficult tumor to treat. Recent advances in adjuvant therapy such as denosumab and innovations in surgical technique in the last 5 years have given providers new options for treatment after a successful diagnosis of the tumor. (2) Methods: Articles published between 1927 and 2021 were selected from PubMed and Scopus searches using key words “Giant Cell Tumor” AND “Lumbar Spine” AND “Treatment”. Relevant articles were reviewed and selected by the authors. (3) Results: A total of 191 articles were discovered. Complete en bloc spondylectomy remains the most definitive treatment option; however, this surgery is challenging and carries a high rate of complication. New adjuvant therapies including denosumab offer a viable alternative to surgery. (4) En bloc spondylectomy remains the gold standard treatment for Giant Cell Tumor of the spine with the lowest published recurrence rate. The use of (neo)adjuvant denosumab improves recurrence rates. More data are needed to determine if denosumab alone is a viable standalone definitive treatment.

Rapid Recurrence of Giant Cell Tumour of C2 Vertebra After Long-Term Denosumab Following Surgical Resection

A 25-year-old man presented with symptoms of cervical myelopathy for 10 days. Imaging revealed an expansile, lytic lesion involving the C2 vertebra completely and compressing the spinal cord, suggestive of giant cell tumor (GCT). Tumor resection and posterior stabilization from C1-C4 were done. Histopathology confirmed the diagnosis of GCT. The patient was kept on adjuvant Denosumab (D-ab) for two years with no signs of recurrence. However, discontinuation of D-ab therapy led to recurrence of the tumor within three months, which was managed with repeated surgical resection and anterior instrumentation followed by radiotherapy. To the best of our knowledge, this is the first reported case of GCT involving the upper cervical spine with rapid recurrence following the stoppage of D-ab therapy.

The current standing on the use of denosumab in giant cell tumour of the bone

Giant cell tumour of the bone (GCTB) has been classically treated surgically. With the advent of denosumab, there is potential to use it as a targeted therapy to downstage the tumour and control its progression. Like all new therapies, the dosage, duration, and long-term effects of treatment can only be determined over the time through numerous trials and errors. The current recommendation of use of the monoclonal antibody is 3-4 months of neoadjuvant denosumab in patients with advanced GCTB for cases who were not candidates for primary curettage initially, and prolonged use for surgically unsalvageable GCTB. The use of Denosumab in the adjuvant setting to prevent recurrence is not established.

Denosumab for Effective Tumor Size Reduction in Patients With Giant Cell Tumors of the Bone: A Systematic Review and Meta-Analysis

BACKGROUND

Denosumab is a human monoclonal antibody that has been used successfully in the treatment of giant cell tumors of bone. These tumors are rare and, in principle, benign, but they are highly aggressive, locally advanced, osteolytic bone tumors that can metastasize to the lungs. Denosumab is an effective treatment when these tumors cannot be surgically removed or when surgical resection is likely to lead to severe morbidity (eg, loss of limbs or joints). The aim of this systematic review and meta-analysis was to investigate patients with giant cell tumors of bone who experienced tumor progression during treatment with denosumab and to compare them with patients who experienced reduction of their giant cell tumors of bone during treatment with denosumab.

METHODS

Embase, Cochrane Library, and MEDLINE/PubMed databases were searched for trials submitted by January 7, 2020, that reported the efficacy and safety of denosumab in patients with giant cell tumors of bone.

RESULTS

Sixty studies were reviewed, involving a total of 1074 patients who had giant cell tumors of bone and were treated with denosumab. Of the 60 studies, 58% of the patients were from case series studies, 39% from open-label phase II studies, and 3% from case reports. The response rate for denosumab as a treatment for giant cell tumors of bone was 97.5%, with statistical significance (P < .0001). Pain in the limbs was statistically the most common adverse event for denosumab treatment in case series studies (P < .0001). No treatment-related deaths occurred in the reviewed studies.

CONCLUSION

Cumulative evidence supports the addition of surgery to optimal medical therapy with denosumab to reduce tumor size, clinical symptoms, and mortality among patients with giant cell tumors of bone.

Molecular Targeted Therapy for the Bone Loss Secondary to Pyogenic Spondylodiscitis Using Medications for Osteoporosis: A Literature Review

Pyogenic spondylodiscitis can cause severe osteolytic and destructive lesions in the spine. Elderly or immunocompromised individuals are particularly susceptible to infectious diseases; specifically, infections in the spine can impair the ability of the spine to support the trunk, causing patients to be bedridden, which can also severely affect the physical condition of patients. Although treatments for osteoporosis have been well studied, treatments for bone loss secondary to infection remain to be elucidated because they have pathological manifestations that are similar to but distinct from those of osteoporosis. Recently, we encountered a patient with severely osteolytic pyogenic spondylodiscitis who was treated with romosozumab and exhibited enhanced bone formation. Romosozumab stimulated canonical Wnt/β-catenin signaling, causing robust bone formation and the inhibition of bone resorption, which exceeded the bone loss secondary to infection. Bone loss due to infections involves the suppression of osteoblastogenesis by osteoblast apoptosis, which is induced by the nuclear factor-κB and mitogen-activated protein kinase pathways, and osteoclastogenesis with the receptor activator of the nuclear factor-κB ligand-receptor combination and subsequent activation of the nuclear factor of activated T cells cytoplasmic 1 and c-Fos. In this study, we review and discuss the molecular mechanisms of bone loss secondary to infection and analyze the efficacy of the medications for osteoporosis, focusing on romosozumab, teriparatide, denosumab, and bisphosphonates, in treating this pathological condition.

Multiprofessional Management of Giant Cell Tumors in the Cervical Spine: A Systematic Review

BACKGROUND

Giant cell tumors of the bone (GCTB) are rare bone tumors, especially in the cervical spine. Generally considered benign, local aggressiveness and metastatic growth have been described. Surgical concepts for GCTB are challenged by complex neurovascular anatomy. Specific clinical management guidelines are nonexistent. This systematic review aims to compile existing evidence on the treatment of GCTB of the cervical spine.

METHODS

Four electronic databases were searched: Medline, Embase, Web of Science, and Cochrane Library. All clinical studies reporting the treatment of GCTB in the human cervical spine in English language were found eligible for review.

RESULTS

Seven studies were included in the synthesis including a total number of 54 patients. Of those patients, 46 (85%) were treated for naive nonrecurrent GCTB. Only 1 study is considered a cohort study; all other studies were case reports. Generally, intralesional procedures were performed in 13 (24%) cases. Subtotal resections were reported for 11 (20%) patients. Twenty-eight (52%) patients were surgically treated with piecemeal resection, en-bloc resection, or spondylectomy. Thirty-six (67%) patients underwent adjuvant radiotherapy. A combination of radiotherapy and chemotherapy was reported in 2 (4%) cases. Bisphosphonates were prescribed for 9 (17%) patients. Inconsistent reporting of outcome data did not allow for comparative analyses.

CONCLUSIONS

Best available evidence suggests that the most aggressive surgical approach should be the main goal of any GCTB surgery. No specific adjuvant or neoadjuvant treatment can be recommended as superior due to a lack of comparative data. Therapeutic approaches need to be planned thoroughly on an individual basis.

Benign Osseous Tumors and Tumor-Like Conditions

We will provide an imaging-focused discussion of 3 benign bone tumors that do not fit in the categories of cartilaginous tumors or osteoid tumors. We have chosen giant cell tumor of bone, unicameral bone cyst, and fibrous dysplasia. All 3 of these entities are common enough that one does not have to be a musculoskeletal radiologist in a cancer hospital to encounter them occasionally, but none of them should be seen frequently.

Incidence, Management, and Outcomes of Spinal Giant Cell Tumor of Bone in Adult Patients: A National Cancer Database Analysis

OBJECTIVE

Giant cell tumors (GCTs) constitute 5% of all primary bone tumors with spinal GCTs (SGCTs) accounting for 2%-15% of all GCTs. The standard of care for SGCT has been maximal surgical resection. However, many adjuvant therapies have been used owing to the difficulty in achieving gross total resection combined with the high local recurrence rate. The purpose of the present study was to analyze the incidence, management, and outcomes of SGCT.

METHODS

Patients with diagnosis codes specific for SGCT were queried from the National Cancer Database from 2004 to 2016. The outcomes were investigated using Cox univariate and multivariate regression analyses, and survival curves were generated for comparative visualization.

RESULTS

The search criteria identified 92 patients in the NCDB dataset from 2004 to 2016 with a diagnosis of SGCT. Of the 92 patients, 64.1% had undergone surgical intervention, 24.8% had received radiotherapy, and 15.2% had received immunotherapy. Univariate analysis revealed that age ≥55 years and tumor location in the sacrum/coccyx were associated with worsened overall survival (OS) and that surgical resection was associated with improved OS. On multivariate analysis, age 55-64 years was associated with worsened OS, and radical surgical resection was associated with improved OS. The survival analysis revealed improved OS with surgery but not with radiotherapy, chemotherapy, or immunotherapy.

CONCLUSION

SGCT is a rare primary bone tumor of the vertebral column. The standard of care has been surgical resection with the goal of gross total resection; however, adjuvant therapies have often been used. Our study found that surgical resection significantly improved OS and that immunotherapy neared significance in improving OS.

Denosumab in the treatment of giant cell tumor of the spine. Preliminary report, review of the literature and protocol proposal

BACKGROUND

The interest on the role of Denosumab in the treatment strategy of giant cell tumor of the spine is growing. En bloc resection is considered the Enneking appropriate treatment, but morbidity and functional loss are sometimes unacceptable. Denosumab could play a role as a stand-alone treatment, but also as preoperative treatment or as postoperative after intralesional surgery.

MATERIALS AND METHODS

A cohort of 10 out of 12 cases of spinal GCT consecutively treated with Denosumab are analyzed and discussed compared to the cases reported in the literature. A staging of the radiological effect of the treatment is proposed.

RESULTS

The stand-alone and postoperative treatments are still running (12 to 88 months). One therapy was stopped after 15 months, once a satisfactory local effect was achieved, but the treatment had to be restarted 2 months later due to the recurrence of the erosive images. The new treatment was successful. At 1-year follow-up after the gross total excision followed by postoperative Denosumab treatment, no evidence of local recurrence was found. The preoperative treatment duration ranged from 3 to 24 months. No local recurrence followed the en bloc resections.

CONCLUSIONS

Denosumab alone is effective in relieving pain, increasing the ossification and sometimes reducing the tumor volume. It can be considered an excellent solution in spine GCTs whose surgical treatment cannot be Enneking appropriate or is associated with unacceptable morbidity or loss of functions. It is still impossible to state when to safely stop the treatment. Denosumab also plays a role as preoperative protocol. These slides can be retrieved under Electronic Supplementary Material.

Can Denosumab cure giant cell tumors of the spine? A case report and literature review

BACKGROUND

Bone giant cell tumors, although benign, may be locally aggressive and cause severe morbidity; in some cases, they can also disseminate at distance and cause death. Denosumab has been approved to treat unresectable bone giant cell tumors or when surgery is likely to result in severe morbidity. Furthermore, its curative potential has been recently suggested.

CASE

An 18-year-old girl presented with a spinal giant cell tumor at T9. Neo-adjuvant denosumab was administered for 9 months with great clinical and analytical tolerance. A posterior left T9 costo-transversectomy and vertebral body curettage was performed and the spine stabilized. Interestingly, histopathology examination of the surgical specimens found no evidence of tumoral cells. Denosumab was reinstated until completion of 12 months of treatment.

CONCLUSION

Denosumab has an important but still limited role in the treatment of spinal giant cell tumors. Here, it resulted in complete histological resolution of the tumor, potentially widening its applicability from a strictly neo-adjuvant to a curative role.

Cervical spine giant cell bone tumor: a case report

Background

Giant cell tumors (GCTs) of the bone are locally aggressive primary bone tumors with a benign character. Spinal involvement is rare and they are quite rare in the cervical spine.

Case presentation

A 31-year-old male patient presented with neck pain. Cervical CT revealed a lytic lesion extending posteriorly and causing the collapse of the C4 vertebra corpus. The patient underwent excision of the tumor extending from the anterior to the posterior with a single-stage anterior intervention followed by the placement of an anterior cage and plate-screw system for fusion. The pathology was reported as GCT.

Conclusions

The posteriorly located lesion was widely curetted through an anterior approach in a single session.

Recurrence of Giant Cell Tumor of the Spine after Resection: A Report of 10 Cases

Objective

To review the clinical details and further treatments for recurrent spinal giant cell tumors (SGCT), and to analyze the risk factors of recurrence and shed new light on the treatment options and prognosis of recurrent SGCT.

Methods

A retrospective analysis of recurrent SGCT between April 2003 and January 2014 was performed. A total of 10 patients comprising 3 men and 7 women with a mean age of 28.9 years (range, 21–40 years) were included in the study. All complete clinical data, radiographs, CT, MRI, scans and pathological data were reviewed. The tumor locations and the regions involved were evaluated by CT and MRI. The blood supply of the tumors was evaluated by enhanced CT and MRI. The mean follow‐up was 81.3 months (range, 35.7–172.1 months).

Results

All patients had Enneking stage 3 tumors; 9 (90%) of them had different extents of spinal canal involvement in the primary time period. All patients underwent intralesional resection during their first surgery. Only 1 patient received local adjuvant treatments; no patient underwent selective arterial embolization or used denosumab at that time. Only 1 patient underwent adjuvant radiotherapy postoperatively, and another patient used bisphosphonates. After recurrence, 1 patient was cured using denosumab, and 2 patients' disease was controlled through use of other medical treatments or adjuvant treatments. There were 3 repeated recurrences and 7 repeated surgical procedures were performed in 5 patients. There were 6 intralesional excisions and 1 decompression surgery. The mean relapse‐free time after the first surgery was 32.3 months (range, 10.5–62.6 months). The overall mean relapse‐free time was 40.2 months (range, 10.5–157 months). No distant metastasis was found in our series. At the final follow‐up, 4 patients were disease free, 3 patients' disease was under control, 2 has progressive disease aggravation, while 1 patient died as a result of progression of disease 133.9 months after first surgery.

Conclusion

Intralesional excision for recurrent spinal giant cell tumors is an effective option that may have satisfactory prognosis. However, the excision and the inactivation of the lesion should be carried out carefully and thoroughly without missing any corners. Early diagnosis of recurrence may be associated with better prognosis. Adjuvant treatments perioperatively and systemic medical treatments can decrease recurrence rates and can have therapeutic effects in the recurrent SGCT.

Surgical treatment outcome of giant cell tumor of distal ulna: En bloc resection vs. curettage and bone graft

Background: Giant cell tumor (GCT) of the bone is a benign neoplasm with local aggressive behavior. Distal ulna is a very rare place for GCT. Published studies have mainly focused on case reports, and thus there is no consistent treatment strategy for this tumor at this location. This retrospective study was conducted to evaluate the oncological and functional results of 2 different surgical treatment methods for GCT in distal ulna.

Methods: In this study, 9 patients with GCT of distal ulna were followed after surgical treatment of GCT of distal ulna. Of the patients, 2 had local recurrence after surgery in other hospitals and 7 had primarily been admitted to our hospital. Four patients, all with grade 2 Enneking and Campanacci’s classification, were treated by extended curettage and bone grafting, while 5 patients with grade 3 were managed by distal ulnar resection. Minimum follow-up time was 24 months.

Results: Patients with grade 3 GCT of distal ulna, who had extended curettage, had a local recurrence up to one year after surgery. Local recurrence was never seen in those with grade 3 disease with resection or in those with grade 2 disease with extended curettage as the treatment of GCT in this location.

Conclusion: Based on our study, which is the largest cohort of GCT of distal ulna, extended curettage, and en bloc resection can be suggested as valuable methods of treatment for grades 2 and 3 tumors, respectively.

Epidemiology of benign giant cell tumor of bone in the Chinese population

Background

Quantifying the incidence of giant cell tumor (GCT) of bone is challenging because it is a rare, histologically benign bone tumor for which population-level statistics are unavailable in most countries. We estimated the 2017 incidence of GCT in China using a direct (registry-based) approach with available population-based data.

Materials and Methods

The most recent age- and sex-specific incidence rates of GCT recorded in the Bone Tumor Registry in Japan (2015) were applied to 2017 age- and sex-matched populations projected by the United Nations for China in order to estimate 2017 incidence. An adjustment factor calculated using registry data suggesting that GCT may represent a greater proportion of bone tumors in China than in Japan (Guo, 1999) was applied to provide secondary estimates.

Results

Annual GCT incidence was estimated to be 1.49 per million population or 2094 new cases in China for 2017. A comparison of this estimated incidence with Japan (1.25 per million) and the United States (1.38 per million) indicates that the incidence is somewhat higher in China using identical methods. Secondary estimates suggest that GCT incidence in China may be as high as 2.57 per million or 3625 new cases in 2017. The corresponding 3-year limited-duration prevalence of GCT in China using a registry-based approach and general age-specific mortality is 6276 (secondary estimate: 10,876).

Conclusions

Leveraging unique population-based registry data, we estimated that GCT is a rare disease in the Chinese population with an incidence ranging between 1.49 and 2.57 cases per million persons per year. Possible differences in diagnostic classification of GCT, urban-rural demographics, and the younger demographic distribution of the Chinese population may underlie observations that GCT, a condition that primarily affects young individuals (20-40 years of age), accounts for a higher proportion of skeletal tumors in China than in other regions.

Solitary juvenile xanthogranuloma in the spine pretreated with neoadjuvant denosumab therapy followed by surgical resection in a 5-year-old child: case report and literature review

PURPOSE

We present a case report that describes neoadjuvant denosumab therapy initiated in a child with a solitary giant cell-rich juvenile xanthogranuloma tumor involving the spine, and review the current literature.

METHODS

A giant cell-rich histiocytic lesion involving the 11th thoracic vertebral body was identified in a healthy 5-year-old girl with persistent back and pelvic pain for several months. Imaging examinations and an open biopsy were performed to obtain a definite pathologic diagnosis. As the tumor appeared to be aggressive in nature, we administered adjuvant therapy with denosumab preoperatively and then performed a total spondylectomy.

RESULTS

Histopathology confirmed that the tumor was juvenile xanthogranuloma. No tumor metastases or recurrence were detected at the 3-year follow-up, and the patient was asymptomatic.

CONCLUSIONS

In giant cell-rich tumors, denosumab is occasionally used as neoadjuvant or adjuvant therapy, especially for tumors in difficult locations or with substantial soft tissue extensions. Rare adverse events in children include skin infections and disruption of calcium homeostasis. Surgical treatment is aimed at removing the tumor and relieving the symptomatic spinal cord compression. Use of denosumab as neoadjuvant therapy for juvenile xanthogranuloma involving the spine has not been reported previously.

Total spondylectomy of recurrent giant cell tumors in the cervical spine: Two case reports and review of literature

RATIONALE

Spinal Giant Cell Tumors (SGCTs) are rare, aggressive, and benign tumors. Their presence in the cervical spine is even more exceptional. There are few reports of cervical GCT in the literature, especially recurrent cases. The treatment are challenging to clinically because radical resection is extremely difficult.

PATIENT CONCERNS

In this study, we present the cases of a 25-year-old man and a 41-year-old woman who suffered from recurrent cervical GCT.

INTERVENTIONS

They underwent extensive total spondylectomy of C3-5 and C2-4, respectively, by a combined anterior and posterior approach.

OUTCOMES

Both patients had a satisfactory prognosis after 2 years followe-up, and extensive total spondylectomy provided good disease-free survival rates. Extensive total spondylectomy of cervical recurrent giant cell tumor was successfully achieved combined anterior and posterior approach.

LESSONS

This surgical technique can be an effective option for this pathological condition, which is difficult to manage using other conventional treatment options including repeated curettage and radiotherapy. However, there are insufficient data on long-term subjective outcomes in this type of patient, and larger series studies are needed to determine the efficacy of this approach, especially compared with piecemeal resection techniques.

Response evaluation of giant-cell tumor of bone treated by denosumab: Histogram and texture analysis of CT images

BACKGROUND

This study aimed to compare computed tomography (CT) features, including tumor size and textural and histogram measurements, of giant-cell tumors of bone (GCTBs) before and after denosumab treatment and determine their applicability in monitoring GCTB response to denosumab treatment.

METHODS

This retrospective study included eight patients (male, 3; female, 5; mean age, 33.4 years) diagnosed with GCTB, who had received treatment by denosumab and had undergone pre- and post-treatment non-contrast CT between January 2010 and December 2016. This study was approved by the institutional review board. Pre- and post-treatment size, histogram, and textural parameters of GCTBs were compared by the Wilcoxon signed-rank test. Pathological findings of five patients who underwent surgery after denosumab treatment were evaluated for assessment of treatment response.

RESULTS

Relative to the baseline values, the tumor size had decreased, while the mean attenuation, standard deviation, entropy (all, P = 0.017), and skewness (P = 0.036) of the GCTBs had significantly increased post-treatment. Although the difference was statistically insignificant, the tumors also exhibited increased kurtosis, contrast, and inverse difference moment (P = 0.123, 0.327, and 0.575, respectively) post-treatment. Histologic findings revealed new bone formation and complete depletion or decrease in the number of osteoclast-like giant cells.

CONCLUSION

The histogram and textural parameters of GCTBs changed significantly after denosumab treatment. Knowledge of the tendency towards increased mean attenuation and heterogeneity but increased local homogeneity in post-treatment CT histogram and textural features of GCTBs might aid in treatment planning and tumor response evaluation during denosumab treatment.

In Vitro Study of the Effects of Denosumab on Giant Cell Tumor of Bone: Comparison with Zoledronic Acid

Giant cell tumor of bone (GCTB) is a locally aggressive primary bone tumor that contains numerous osteoclasts formed from marrow-derived precursors through receptor activator of nuclear factor κ-B ligand (RANKL), an osteoclast differentiation factor expressed in neoplastic cells of GCTB. Denosumab, a fully human monoclonal antibody targeting RANKL, has recently been used for the treatment of GCTB, and superior treatment effects have been reported. The aim of this work was to elucidate the mechanism of action of denosumab, and the differences between denosumab and zoledronic acid at the level of GCTB cells. We isolated GCTB cells from 3 patients and separated them into osteoclasts, osteoclast precursors and proliferating spindle-shaped stromal cells (the true neoplastic component), and examined the action of denosumab on differentiation, survival and bone resorption activity of osteoclasts. Denosumab and zoledronic acid inhibited osteoclast differentiation from mononuclear cells containing osteoclast precursors. Zoledronic acid inhibited osteoclast survival, whereas an inhibitory effect of denosumab on osteoclast survival was not observed. The inhibitory effect on bone resorption by both agents was confirmed in culture on dentin slices. Furthermore, zoledronic acid showed dose-dependent inhibition of cell growth of neoplastic cells whereas denosumab had no inhibitory effect on these cells. Denosumab has an inhibitory effect on osteoclast differentiation, but no inhibitory effects on survival of osteoclasts or growth of neoplastic cells in GCTBs.

Efficacy and Safety of Selective Arterial Embolization in the Treatment of Aneurysmal Bone Cyst of the Mobile Spine: A Retrospective Observational Study

STUDY DESIGN

A retrospective observational study.

OBJECTIVE

Our aim is to define the efficacy and safety of serial selective arterial embolization (SAE) in the treatment of aneurysmal bone cysts (ABCs), to explore potential treatment alternatives, and to define a therapeutic algorithm.

SUMMARY OF BACKGROUND DATA

ABC is a benign lesion with an unpredictable behavior. Its treatment is challenging especially in poorly accessible surgical areas, such as spine and pelvis. Currently, the first-line treatment of ABC is repeated SAE until healing. Other options have been used with variable success rates.

METHODS

From January 2004 to September 2015, 23 patients affected by ABC of the mobile spine have been treated with SAE and prospectively followed up by computed tomographic scan and magnetic resonance imaging. Signs of neurological deficit, complications, healing of the lesion, and clinical outcomes were registered.Signs of healing are defined as peripheral sclerotic bone rim formation, decrease of the ABC mass, disappearance of the double content image, and bone formation inside the ABC mass, associated with remission of pain.

RESULTS

Twenty-three patients underwent SAE according to the protocol. Seventeen patients have healed. The number of procedures necessary to obtain healing (clinical and radiographic) varied from 1 to 10. No complication occurred during the procedure. Follow-up time ranged from 5 to 120 months after the last angiographic procedure. All 17 patients had complete relief of pain symptoms. Six patients did not respond to SAE, presenting a progressive clinical and radiographic worsening, and underwent other medical or minimally invasive treatments.

CONCLUSION

Our study confirms the safety of SAE. The efficacy of the treatment was however lower than expected. SAE is indicated when pathological fracture or signs of cord damage are not detected. Infiltration with autologous bone marrow concentrate or administration of Denosumab is under investigation as alternative choices of treatment.

LEVEL OF EVIDENCE

4.

Giant Cell Tumor of Cervical Spine Presenting as Acute Asphyxia: Successful Surgical Resection After Down-Staging With Denosumab

STUDY DESIGN

Case report and literature review.

OBJECTIVE

To describe treatment of a unique case of acute airway obstruction by a large C7 giant cell tumor (GCT) with preoperative denosumab followed by surgical resection, and review the literature on this rare entity.

SUMMARY OF BACKGROUND DATA

Standard treatment for GCTs includes surgical resection or curettage and packing. Large lesions in the spine may require preoperative therapy with denosumab, a human monoclonal antibody to RANKL, to facilitate surgery. It is highly unusual for GCT arising in cervical spine to present with acute asphyxia (requiring tracheostomy).

METHODS

We report a patient with large C7 GCT that caused tracheal compression with almost complete airway obstruction requiring emergency intubation.

RESULTS

The tumor responded to subcutaneously administered denosumab with marked decrease in size and relief of symptoms. Increased tumor mineralization in response to therapy facilitated subsequent successful surgical tumor resection. The patient remains symptom-free 2 years after surgery without tumor recurrence.

CONCLUSION

Denosumab can shrink the size of large GCTs, providing symptom relief before surgery and facilitate tumor resection.

LEVEL OF EVIDENCE

5.

Giant cell tumor of the thoracic spine completely removed by total spondylectomy after neoadjuvant denosumab therapy

PURPOSE

Denosumab, a novel monoclonal antibody that targets the receptor activator of nuclear factor-κB (RANK) ligand (RANKL), has recently been used to treat patients with giant cell tumor of bone (GCTB). However, few reports have described the clinical results of denosumab therapy for spinal GCTB and evaluated treatment efficacy with respect to the entirety of the resected vertebra after denosumab therapy.

METHODS

We present the case of a 51-year-old man with T12 GCTB that was completely removed by a total spondylectomy following 10 courses of neoadjuvant denosumab therapy. Post-therapy radiological findings indicated epidural tumor reduction in the spinal canal and sclerotic rim formation. However, the affected vertebra collapsed despite denosumab therapy and a massive bridging callus formation was present between the spinal GCTB and adjacent vertebra.

RESULTS

These morphological changes made the tumor margins unclear and increased the difficulty of dissection of the segmental arteries from the vertebral body and en bloc corpectomy by a posterior-approach. Pathological findings indicated increased woven bone at the peripheral lesion of the resected vertebra and RANKL-positive stromal cells remained around the woven bone.

CONCLUSIONS

These findings support that GCTB stromal cells survived around the newly formed woven bone after long-term denosumab treatment and total surgical resection of such primary spinal lesions as the gold-standard treatment, even following administration of denosumab. Surgeons should note that prolonged adjuvant denosumab therapy may increase the difficulty of performing a posterior-approach total en bloc spondylectomy.

Giant cell tumour of bone in the denosumab era

Giant cell tumour of bone (GCTB) is an intermediate locally aggressive primary bone tumour, occurring mostly at the meta-epiphysis of long bones. Overexpression of receptor activator of nuclear factor kappa-B ligand (RANKL) by mononuclear neoplastic stromal cells promotes recruitment of numerous reactive multinucleated osteoclast-like giant cells, causing lacunar bone resorption. Preferential treatment is curettage with local adjuvants such as phenol, alcohol or liquid nitrogen. The remaining cavity may be filled with bone graft or polymethylmethacrylate (PMMA) bone cement; benefits of the latter are a lower risk of recurrence, possibility of direct weight bearing and early radiographic detection of recurrences. Reported recurrence rates are comparable for the different local adjuvants (27-31%). Factors increasing the local recurrence risk include soft tissue extension and anatomically difficult localisations such as the sacrum. When joint salvage is impossible, en-bloc resection and endoprosthetic joint replacement may be performed. Local tumour control on the one hand and maintenance of a functional native joint and quality of life on the other hand are the main pillars of surgical treatment for this disease. Current knowledge and development in the fields of imaging, functional biology and systemic therapy are forcing us into a paradigm shift from a purely surgical approach towards a multidisciplinary approach. Systemic therapy with denosumab (RANKL inhibitor) or zoledronic acid (bisphosphonates) blocks, respectively inhibits, bone resorption by osteoclast-like giant cells. After use of zoledronic acid, stabilisation of local and metastatic disease has been reported, although the level of evidence is low. Denosumab is more extensively studied in two prospective trials, and appears effective for the optimisation of surgical treatment. Denosumab should be considered in the standard multidisciplinary treatment of advanced GCTB (e.g. cortical destruction, soft tissue extension, joint involvement or sacral localisation) to facilitate surgery at a later stage, and thereby aiming at immediate local control. Even though several questions concerning optimal treatment dose, duration and interval and drug safety remain unanswered, denosumab is among the most effective drug therapies in oncology.

Neurological Recovery in Two Patients with Cauda Equina Syndrome Secondary to L5 Lumbar Spine Giant Cell Tumour after Treatment with Denosumab without Surgery

We report two patients with cauda equina syndrome (CES) secondary to L5 giant cell tumour (GCT) who achieved good neurological recovery after treatment with denosumab without surgery. The first patient was a 26-year-old man with L5 GCT causing CES who regained bowel and urinary control, muscle power improvement from grade 2 to grade 4 and Oswestry disability index (ODI) improvement from 48 to 23 after denosumab treatment. The second patient was a 25-year-old woman with L5 GCT causing CES who regained bowel and urinary control, muscle power improvement from grade 0 to grade 4 and ODI improvement from 42 to 20 after denosumab treatment. The usage of denosumab in the treatment of patients with CES due to GCT allows potential neurological recovery without any surgical intervention. If surgery is not contraindicated, more time is obtained to prepare the patient preoperatively to attain safer surgery and to achieve complete tumour clearance.

Current status and unanswered questions on the use of Denosumab in giant cell tumor of bone

Denosumab is a monoclonal antibody to RANK ligand approved for use in giant cell tumour (GCT) of bone. Due to its efficacy, Denosumab is recommended as the first option in inoperable or metastatic GCT. Denosumab has also been used pre-operatively to downstage tumours with large soft tissue extension to allow for less morbid surgery. The role of Denosumab for conventional limb GCT of bone is yet to be defined. Further studies are required to determine whether local recurrence rates will be decreased with the adjuvant use of Denosumab along with surgery. The long term use and toxicity of this agent is unknown as is the proportion of patients with primary or secondary resistance. It is advised that complicated cases of GCT requiring Denosumab treatment should be referred and followed up at expert centres. Collaborative studies involving further clinical trials and rigorous data collection are strongly recommended to identify the optimum use of this drug.

Interest of Denosumab for the Treatment of Giant-cells Tumors and Aneurysmal Bone Cysts of the Spine. About Nine Cases

STUDY DESIGN

A prospective cohort study.

OBJECTIVE

The aim of this study was to evaluate the interest of denosumab in the treatment of spinal giant-cells tumors (GCTs) and aneurysmal bone cysts (ABCs).

SUMMARY OF BACKGROUND DATA

To treat GCTs and ABCs, surgical resection remains the best treatment to limit local recurrence (LR) but constitutes an aggressive treatment with potential morbidity. Denosumab, a human antibody anti-RankL, inhibiting the differentiation of osteoclasts, could be an alternative treatment to avoid aggressive surgery.

METHODS

Patients suffering from GCTs and ABCs of the spine were included. Patients received a monthly subcutaneous injection of denosumab (120 mg) during a minimum of 6 months either as a neoadjuvant or as an adjuvant therapy. In association with denosumab, an osteosynthesis was added in case of vertebral fracture and a laminectomy in case of spinal cord compression. Clinical and computed tomography (CT)-scan outcomes were analyzed.

RESULTS

Eight GCTs and one ABC were included. The mean age was 35 years (range: 22-55 yr). Five patients had neurologic deficit. All patients were operated: six osteosynthesis, one "en bloc" resection, four curettages, and two of them associated with an osteosynthesis. Average duration of denosumab therapy was 12.9 months (range: 3.2-24 months). Among them, four patients began denosumab 6 months at least before the surgery. With a mean follow-up of 19.3 months (range: 3.2-52.4 months), back pain and neurologic deficit improved for all patients. Systematic CT-scan at 6 months showed decrease of tumor size and bone consolidation. Regarding patients treated by neoadjuvant denosumab treatment, intraoperative histologic analysis showed an absence of giant cells and a maximum of 10% of alive tumor cells.

CONCLUSION

Denosumab allows bone formation and tumor regression with a maximum efficacy after 6 months of treatment without widely substituting surgery. Long-term results are mandatory to confirm the interest of denosumab and to evaluate LR when stopping denosumab.

LEVEL OF EVIDENCE

3.

Remarkable regression of a giant cell tumor of the cervical spine treated conservatively with denosumab: A case report

INTRODUCTION

Wide resection of giant cell tumors at the cervical spine is sometimes extremely challenging, especially in cases where tumors extend into the nearby tissues, such as vertebral arteries, the spinal cord, or spinal nerve roots. Denosumab, a human monoclonal antibody that binds the receptor activator of nuclear factor κ-β ligand, is reported to be effective for decreasing resorption of giant cell tumor of the bone, but the detailed progress of giant cell tumors in the cervical spine extending into the nearby tissues after such treatment has not been reported.

PRESENTATION OF CASE

A 41-year-old man presented with neck pain. Computed tomography-guided needle biopsy showed numerous giant cells with a large vesicular nucleus, consistent with a giant cell tumor. Because of the extension of the tumor with involvement of the vertebral artery and surrounding tissues, denosumab (120mg) was administered subcutaneously once per month for 24 months. Six months after denosumab treatment, follow-up computed tomography revealed a dramatic regression and osteosclerosis of the tumor. Two years after starting denosumab treatment, positron emission tomography showed no tumor recurrence.

DISCUSSION

Although the tumor was extended with involvement of the surrounding tissues and surgery following denosumab treatment was not performed, at 24 months since initiation of denosumab treatment we confirmed complete regression radiographically.

CONCLUSIONS

Denosumab may be used as an adjuvant by which to avoid or reduce the risks and morbidity of surgical treatment in patients with spinal giant cell tumors extending into nearby tissues.

Surgical Outcomes in Patients with High Spinal Instability Neoplasm Score Secondary to Spinal Giant Cell Tumors

Study Design Retrospective review. Objective To describe the surgical outcomes in patients with high preoperative Spinal Instability Neoplastic Score (SINS) secondary to spinal giant cell tumors (GCT) and evaluate the impact of en bloc versus intralesional resection and preoperative embolization on postoperative outcomes. Methods A retrospective analysis was performed on 14 patients with GCTs of the spine who underwent surgical treatment prior to the use of denosumab. A univariate analysis was performed comparing the patient demographics, perioperative characteristics, and surgical outcomes between patients who underwent en bloc marginal (n = 6) compared with those who had intralesional (n = 8) resection. Results Six patients underwent en bloc resections and eight underwent intralesional resection. Preoperative embolization was performed in eight patients. All patients were alive at last follow-up, with a mean follow-up length of 43 months. Patients who underwent en bloc resection had longer average operative times (p = 0.0251), higher rates of early (p = 0.0182) and late (p = 0.0389) complications, and a higher rate of surgical revision (p = 0.0120). There was a 25% (2/8 patients) local recurrence rate for intralesional resection and a 0% (0/6 patients) local recurrence rate for en bloc resection (p = 0.0929). Conclusions Surgical excision of spinal GCTs causing significant instability, assessed by SINS, is associated with high intraoperative blood loss despite embolization and independent of resection method. En bloc resection requires a longer operative duration and is associated with a higher risk of complications when compared with intralesional resection. However, the increased morbidity associated with en bloc resection may be justified as it may minimize the risk of local recurrence.

Management of spinal giant cell tumors

BACKGROUND CONTEXT

Spinal giant cell tumors (SGCT) remain challenging tumors to treat. Although advancements in surgical techniques and adjuvant therapies have provided new options for treatment, evidence-based algorithms are lacking.

PURPOSE

This study aims to review the peer-reviewed literature that addresses current treatment options and management of SGCT, to produce an evidence-based treatment algorithm.

STUDY DESIGN/SETTING

A systematic review was performed.

METHODS

Articles published between January 1, 1970 and March 31, 2015 were selected from PubMed and EMBASE searches using keywords "giant cell tumor" AND "spine" AND "treatment." Relevant articles were selected by the authors and reviewed.

RESULTS

A total of 515 studies were identified, of which 81 studies were included. Complete surgical resections of SCGT resulted in the lowest recurrence rates. However, morbidity of en bloc resections is high and in some cases, surgery is not possible. Intralesional resection can be coupled with adjuvant therapies, but evidence-based algorithms for use of adjuvants remain elusive. Several recent advancements in adjuvant therapy may hold promise for decreasing SGCT recurrence, specifically stereotactic radiotherapy, selective arterial embolization, and medical therapy using denosumab and interferon.

CONCLUSIONS

Complete surgical resection of SGCT should be the goal when possible, particularly if neurologic impairment is present. Denosumab holds promise as an adjuvant and perhaps stand-alone therapy for SGCT. Spinal giant cell tumors should be approached as a case-by-case problem, as each presents unique challenges. Collaboration of spine surgeons, radiation oncologists, and medical oncologists is the best practice for treating these difficult tumors.

Giant cell tumor of cervicothoracic region treated by triple corpectomy from posterior only approach: A case report with review of literature

Giant cell tumor (GCT) is a benign aggressive tumor, which affects axial as well as a peripheral skeleton. It affects epiphysis of long bones and can result in pathological fractures. GCT affects cervical spine rarely and has been known to affect almost all vertebra in the human body. It has a predilection for fixed spine, that is, sacrum though it can affect mobile spine as well. GCT of cervicothoracic region poses a challenge for the surgeon because of the difficulty in approaching this region anteriorly. This situation is further compounded when GCT involves multiple contiguous vertebral bodies in this region and has already spread beyond the confines of its capsule. We report a case of GCT involving three vertebral bodies C7, D1, and D2 at cervicothoracic region who presented to us and was treated with triple corpectomy from the posterior only approach. This is the first ever case report of triple corpectomy and anterior reconstruction by a posterior only approach for GCT at the cervicothoracic junction to the best of author's knowledge.

Giant cell tumor: rapid recurrence after cessation of long-term denosumab therapy

We report a case of rapid recurrence of a giant cell tumor (GCT) of the distal radius in a 24-year-old woman following the cessation of long-term denosumab therapy. GCT of bone is a histologically benign tumor with multinucleated giant cells on a background of mononuclear giant cells usually presenting as a well-defined epi-metaphyseal lytic lesion without sclerotic margins. Denosumab, a monoclonal antibody to the receptor activator of nuclear factor kappa-B ligand (RANKL), has proven to be an effective neoadjuvant treatment for GCT. The tumor in this case had demonstrated a good response with sustained control for over 2 years while on denosumab therapy. However, within 2 months of cessation of therapy, the tumor demonstrated rapid recurrence and progression with growth, osteolysis, and increased soft tissue component. Despite reinitiating denosumab therapy, there was progressive tumor growth and destruction, ultimately necessitating below-the-elbow amputation. This case illustrates the need for maintenance of denosumab therapy for GCT of bone or definitive surgical treatment prior to its cessation.

Effect of denosumab on recurrent giant cell reparative granuloma of the lumbar spine

STUDY DESIGN

A case of recurrent giant cell reparative granuloma (GCRG) of the lumbar spine successfully treated with denosumab is reported; a fully human monoclonal antibody against the receptor activator of nuclear factor kappa B (RANK) ligand (RANKL).

OBJECTIVE

To report the first case of recurrent GCRG of the lumbar spine treated with denosumab.

SUMMARY OF BACKGROUND DATA

GCRG is a non-neoplastic osteofibrous lesion usually found in the maxilla and mandible but rarely in the spine. It is clinically distinct from giant cell tumor of bone (GCTB), although common histological characteristics such as the proliferation of spindle-shaped stromal cells and multinucleated giant cells are shared. Denosumab has recently been reported to be effective for unresectable GCTB; however, there is only one report of its effect on GCRG. Moreover, the effect of denosumab on GCRG of the spine is unknown.

METHODS

The clinical course, radiological features, pathology, and treatment outcome of a patient with recurrent GCRG of the lumbar spine treated with denosumab are documented.

RESULTS

Denosumab treatment was used for this patient with unresectable recurrent GCRG of the lumbar spine. Follow-up lumbar radiography showed significant bone formations in the tumor lesion after 3 months of treatment. On follow-up computerized tomography scans of the L2 and L3 vertebral lesions, the replacement of osoteolytic lesions by the formation of cortical-like bone tissue was clearly identified.

CONCLUSION

We report the first case of recurrent GCRG of the spine successfully treated with denosumab. Treatment with denosumab induced significant bone formation in the unresectable lumbar lesion with stable clinical improvement during the 12-month follow-up period without apparent complications. Denosumab shows promise as a new alternative treatment option for osteoclastic giant cell-rich tumors, such as GCRG, especially for unresectable lesions of the spine.

LEVEL OF EVIDENCE

4.

RANK pathway in giant cell tumor of bone: pathogenesis and therapeutic aspects

Giant cell tumor is a relatively uncommon but painful tumor of bone, which can metastasize to the lungs. The RANK pathway is often reported to be involved in the pathogenesis of giant cell tumor of bone (GCTB). This pathway is a key signaling pathway of bone remodeling that plays a critical role in differentiation of precursors into multinucleated osteoclasts, and activation of osteoclasts leading to bone resorption. Dysregulation of RANK ligand (RANKL)-RANK-osteoprotegerin (OPG) signaling cascade induces the imbalance between bone formation and bone resorption, which leads to the changes in bone mass, increases osteoclast-mediated bone destruction, bone metastasis, and the progression of existing skeletal tumors. Recent evidences have shown that targeting the components of RANKL-RANK-OPG signaling pathway is a promising approach in the treatment of GCTB. This review study has focused on the association of RANKL-RANK-OPG pathway in the pathogenesis and progression of GCTB as well as discussed the possible therapeutic strategies by targeting this pathway.

Regional variation and challenges in estimating the incidence of giant cell tumor of bone

BACKGROUND

Estimating the incidence of giant cell tumor of bone is challenging because few population-based cancer registries record benign bone tumors. We compared two approaches, the indirect (relative index) estimation approach used in The Burden of Musculoskeletal Diseases in the United States (BMUS) and a direct incidence rate approach (from registries that record giant cell tumor), to estimate giant cell tumor incidence in France, Germany, Italy, Spain, the U.K., Sweden, Australia, Canada, Japan, and the U.S.

METHODS

Giant cell tumor of bone incidence was calculated with use of the BMUS relative index of giant cell tumor to osteosarcoma in three scenarios (low, base case, and high) from case series. We compared the BMUS approach with the latest data from tumor registries in Australia (1972 to 1996), Japan (2006 to 2008), and Sweden (1993 to 2011) that record giant cell tumors. United Nations population estimates were used to project results to 2013.

RESULTS

The low scenario in the BMUS approach reflects data from Unni and Inwards; the incidence of giant cell tumor of bone is 0.34 relative to osteosarcoma. As the incidence of osteosarcoma is 31.4% of the total incidence of bone and joint cancers, the incidence of giant cell tumor is 0.11 times that of all bone and joint cancers. The base scenario reflects the series by Mirra et al., with a giant cell tumor incidence of 0.47 relative to osteosarcoma (0.15 to all bone and joint cancers). The high scenario reflects the series by Ward, with an incidence of 0.84 relative to osteosarcoma (0.26 to all bone and joint cancers). Differences among the three series reflect referral to a national center of excellence compared with referral to a local oncology practice. Registry data indicated a giant cell tumor incidence rate per million per year of 1.33 in Australia, 1.03 in Japan, and 1.11 in Sweden in 2013. The estimated incidence rate per million in the ten countries in 2013 ranged from 1.03 (Japan) to 1.17 (Canada) with use of the registry-based approach and from 0.73 (Japan) for the low scenario) to 2.20 (Germany) for the base case with use of the BMUS approach.

CONCLUSIONS

Giant cell tumor of bone affects approximately one person per million per year in the ten countries studied. Estimates derived with use of age-specific incidences from tumor registries were typically within the range of the low and base case BMUS scenarios. We recommend the registry-derived method for estimating the incidence of giant cell tumor.