Denosumab in advanced/unresectable giant-cell tumour of bone (GCTB): For how long?

Denosumab combined with en bloc resection and arthrodesis for recurrent grade 3 giant cell tumor of bone in distal radius

PURPOSE

This study aimed to analyse the clinical outcomes of preoperative adjuvant denosumab therapy (PADT) combined with resection and arthrodesis for recurrent grade 3 giant cell tumor of bone (GCTB) in the distal radius.

METHODS

A retrospective study was conducted on twenty-three patients (8 males, 15 females) who were treated with the adjuvant denosumab combined with en bloc resection (EBR) and arthrodesis for biopsy confirmed recurrent Campanacci III giant cell tumor of bone in the distal radius between January 2015 and December 2022. All 23 patients were treated with wrist arthrodesis reconstruction using autogenous free iliac crest bone graft (ICBG), bridging plate and screws. The local control, metastasis and overall survival were evaluated during the follow-up period. Functional outcomes were evaluated using the Disabilities of the Arm, Shoulder and Hand (DASH) score, Musculoskeletal Tumor Society Score (MSTS-87 and MSTS-93), and grip strength in the follow-up period. Additionally, all surgical or denosumab-related complications that occurred were recorded in this study.

RESULTS

Twenty-three patients were included in this retrospective study and no patients were lost in the follow-up period. The average patient age was 32.5 ± 10.2 years (range, 19-53 years) and the mean follow-up time was 35.5 ± 18.4 months (range, 13-72 months). The average tumor length was 71.7 ± 8.7 mm (range, 50 to 85 mm) and bone reconstruction length was 78.5 ± 8.5 mm (range, 60 to 90 mm). Four patients (17.4%) had secondary local recurrence after reoperation and two patients had (8.7%) multiple recurrences. One patient (4.3%) was deceased in the last follow-up due to multiple metastases. The estimated 5-year recurrence-free survival rate was 81.3% and 5-year metastasis-free survival rate was 95.7%. The mean union time was 8.5 ± 1.9 (6-12) months and the overall survivorship of the allograft was 82.7% (21/23) at an average 35 month follow-up. The average MSTS-87 and MSTS-93 scores were 27.8 ± 1.6 (range, from 23 to 30) and 91.5 ± 5.0 (range, from 76 to 100), and the average DASH score was 8.9 ± 3.2 (range, from 3 to 15), respectively. The average grip strength was 64.6 ± 15.7% (range, from 30 to 95%) of the uninvolved side. Eight patients (34.7%) had at least one complication in the follow-up time. Two autografts (8.7%) were removed due to local recurrence and bone nonunion, and the average autograft survival time was 32.8 ± 18.5 months (range, 12 to 72 months).

CONCLUSIONS

Preoperative adjuvant denosumab therapy (PADT) combined with en bloc resection and arthrodesis is a promising method for the treatment of recurrent Campanacci III GCTB in distal radius with acceptable short-term local control and functional satisfaction.

LEVEL OF EVIDENCE

level IV Therapeutic.

The successful control of multiple pulmonary metastasis from giant cell tumor of bone by monthly denosumab administration: A case report

Giant cell tumor of bone (GCTB) is a locally aggressive benign neoplasm that is associated with a large biological spectrum ranging from latent benign to highly recurrent and occasionally metastatic tumor. In this article, we present a case of a 37-year-old woman who presented with fracture at the distal femur due to GCTB. Bone segment resection and reconstruction were done, and histopathology showed tumor features for GCTB. Later, multiple lung metastasis was found 22 months post-operation, which was verified by biopsy. Then systemic denosumab therapy with different intervals (1-month and 2-month) was tried as the treatment. It was clarified that monthly denosumab administration, instead of 2-month interval, was required to control the progression of the unresectable multiple lung metastasis from GCTB, which could be a choice for the future treatment of these patients.

Italian position paper (SIPMO-SICMF) on medication-related osteonecrosis of the jaw (MRONJ)

OBJECTIVE

This paper aims to describe the 2023 update position paper on MRONJ developed by the Italian Societies of Oral Pathology and Medicine (SIPMO) and of Maxillofacial Surgery (SICMF).

METHODS

This is the second update following the 2013 and 2020 Italian position papers by the Expert panel, which is a representation of the two scientific societies (SIPMO and SICMF). The paper is based on an extensive analysis of the available literature from January 2003 to February 2020, and the subsequent review of literature conducted between March 2020 and December 2022 to include all new relevant published papers to confirm or modify the previous set of recommendations.

RESULTS

This position paper highlights the main issues of MRONJ on risk estimates, disease definition, diagnostic pathway, individual risk assessment, and the fundamental role of imaging in the diagnosis, classification, and management of MRONJ.

CONCLUSION

The Expert Panel confirmed the MRONJ definition, the diagnostic work-up, the clinical-radiological staging system and the prophylactic drug holiday, as recognized by SIPMO-SICMF; while, it presented novel indications regarding the categories at risk of MRONJ, the prevention strategies, and the treatment strategies associated with the therapeutic drug holiday.

Drug assumption and awareness about adverse drug reactions. The right to know. The case of the bone-modyfing agents: a systematic review

Introduction

Medication-related osteonecrosis of the Jaw (MRONJ) is an adverse drug reaction that affects the mandible and maxilla of patients exposed to BMA and AA therapies, causing the progressive destruction and death of bone. To date, oral health preventive measures remain the most effective strategy to reduce MRONJ incidence, and, in this sense, the major goal is to diagnose, treat, and eradicate any oral diseases that could compromise oral health. The present systematic review aims to investigate the awareness of MRONJ among patients assuming BMAs.

Methods

A systematic literature search was performed, selecting studies that concern the awareness of patients of the risk of MRONJ.

Results

Six studies were included in this review. In total, 483 patients were evaluated. Of the 483 included patients, 391 were not aware of the possibility of MRONJ onset (391/483, 81%) and 92 were aware of it (92/483, 19%).

Discussion

The problem of patient's lack of awareness with respect to MRONJ risk presents different layers of complexity ("what?", "who?", "where?", "when?" and "why?"). Among its causal factors, there are an inadequate level of communication with patients and the lack of collaboration between healthcare professionals, which is related to an individualistic view of liability and deontological duties. MRONJ is a drug adverse reaction that can greatly affect the quality of life of patients if not promptly diagnosed and treated. Therefore, patients must be fully aware of the risks of adverse and the importance of preventive measures, which imply effective and exhaustive communication by each member of the multidisciplinary team. Effective teamwork and collaborative care should be promoted to positively impact patients' awareness.

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.

Current Concepts in the Treatment of Giant Cell Tumor of Bone: An Update

Curettage is recommended for the treatment of Campanacci stages 1-2 giant cell tumor of bone (GCTB) in the extremities, pelvis, sacrum, and spine, without preoperative denosumab treatment. In the distal femur, bone chips and plate fixation are utilized to reduce damage to the subchondral bone and prevent pathological fracture, respectively. For local recurrence, re-curettage may be utilized when feasible. En bloc resection is an option for very aggressive Campanacci stage 3 GCTB in the extremities, pelvis, sacrum, and spine, combined with 1-3 doses of preoperative denosumab treatment. Denosumab monotherapy once every 3 months is currently the standard strategy for inoperable patients and those with metastatic GCTB. However, in case of tumor growth, a possible malignant transformation should be considered. Zoledronic acid appears to be as effective as denosumab; nevertheless, it is a more cost-effective option. Therefore, zoledronic acid may be an alternative treatment option, particularly in developing countries. Surgery is the mainstay treatment for malignant GCTB.

Effect of denosumab in treatment of unresectable spine and sacrum giant cell tumor of bone

Giant cell tumor of bone (GCTB) is a rare tumor of the bone that is locally invasive. Surgery is the primary treatment that is usually done by intralesional curettage. In pelvis and spine surgery may be associated with high rate of complications, recently, Denosumab has been proposed for the treatment of these tumors in latter anatomical regions. Denosumab may be administered alone or as an adjuvant to surgery. This study aimed to assess the treatment effects of Denosumab in patients with unresectable GCTB. This study was a case series. Patients with unresectable GCTB of vertebra and sacrum were enrolled in this study. Patients received 120 mg of monthly Denosumab and additional doses on days 8th and 15th of treatment. Images of patients before and after treatment were evaluated. Nine patients with a median age of 30 years with spine and sacrum GCTB were included in this study. The median time of treatment with denosumab was 28 months (range: 3-67). Tumor control was seen in all patients. According to Inverse Choi density/size (ICDS), criteria objective response (complete response and partial response) was seen in 8 patients, and one had stable disease. Based on CT scan images, in 4 patients (44.44%), less than 50% of the transverse diameter of the tumor became ossified, and in the other five patients (55.55%), more than 50% of the tumor's transverse diameter became ossified. The median tumor volume before treatment was 829 cm3, and after treatment was 504 cm3 which was significantly reduced (P = 0.005). No complication related to therapy was seen. Tumor response was seen in all patients, and tumor control according to ICDS criteria was evident in all cases. This finding was in line with previous studies. Clinical improvement of signs and symptoms was also seen in all patients. Generally, our study demonstrates a sustained clinical benefit and tumor response with Denosumab, as tumor response ≥ 24 weeks was evident in all cases. No side effects were seen in patients despite long-term treatment with Denosumab.

Using Denosumab as a Nonsurgical Management of Aneurysmal Bone Cysts in the Pelvis

Background

Aneurysmal bone cysts (ABCs) are infrequent, benign, and locally destructive lesions that most commonly occur during the first two decades of life. They usually affect the metaphysis of the long bones, but the pelvis is involved in 8%-12% of the cases. The management of pelvic ABCs is a challenging issue due to difficulties in choosing the appropriate approach, adjacent neurovascular bundles, the risk of intraoperative bleeding with difficulty achieving good hemostasis, and the risk of injury to the hip or sacroiliac joints. Limited data exist concerning the use of denosumab as a non-surgical treatment for pelvic ABCs. Our hypothesis was that denosumab might be an effective and safe solo treatment of cases with ABCs in the pelvis.

Methods

We retrospectively assessed 20 patients with ABCs in the pelvis, who were treated by denosumab as a solo agent without surgery. Patients were assessed regarding disease control, the incidence of recurrence and non-oncological complications, and functional outcome.

Results

The mean follow-up period was 38.5 months. Disease control was achieved in 16 patients (80%), with no local recurrence. Tolerable drug-related complications occurred in 15% of cases. The mean Musculoskeletal Tumor Society score was 92.3%.

Conclusions

Denosumab may provide a reliable option in the nonsurgical treatment of ABCs of pelvic origin with expected lower morbidity than the surgical solution and tolerable complications. Further studies on the safety profile and long-term effects of denosumab especially in skeletally immature patients are required.

Denosumab for giant cell tumors of bone from 2010 to 2022: a bibliometric analysis

Giant cell tumors of the bone (GCTB) are considered moderately malignant bone tumors. Denosumab, as a neoadjuvant therapy, provides new possibilities for treating GCTB. However, even after multiple studies and long-term clinical trials, there are limitations in the treatment process. Research data and Medical Subject Headings terms related to denosumab and GCTB were collected from January 2010 to October 2022 using the Web of Science and MeSH ( https://meshb.nlm.nih.gov ) browsers. These data were imported into CiteSpace and VOSviewer softwares for bibliometric analysis. Overall, 445 publications on denosumab and GCTB were identified. Over the last 12 years, the growth rate of the total number of publications has remained relatively stable. The USA published the highest number of articles (83) and had the highest centrality (0.42). Amgen Inc. and Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) First Ortoped Rizzoli were identified as the most influential institutions. Many authors have made outstanding contributions to this field. Lancet Oncology had the highest journal impact factor (54.433). Local recurrence and drug dosage are current research hotspots, and future development trends will mainly focus on prognostic markers of GCTB and the development of new therapies. Further research is required to analyze denosumab's safety and efficacy and understand its local recurrence of GCTB, to identify the optimal dose. Future progress in this field will likely focus on exploring new diagnostic and recurrence markers to monitor disease progression and examine new therapeutic targets and treatment strategies.

Management of a rare mandibular giant cell tumor of bone by neoadjuvant denosumab therapy and surgery: A 4-year follow-up case report

INTRODUCTION

Giant cell tumor of bone (GCTB) is a very rare tumor encountered in the jaws and its histology is quite similar to the more common giant cell granuloma of the jaws (GCGJ). These two entities can be easily confused in maxillofacial region. They are classically managed surgically, but in some localizations and in specific medical-surgical contexts, neoadjuvant therapy with denosumab may be indicated. This report tends to reinforce existing evidence in favor of the use of a neoadjuvant approach, particularly for localization of GCTB in the orofacial region.

PRESENTATION OF CASE

This is a 57-year-old female patient, an alcoholic smoker, in whom a voluminous mandibular radiolucent lesion was discovered during a routine X-ray by her dentist. After medical imaging assessment and incisional biopsy, diagnosis of GCTB was established. A neoadjuvant denosumab therapy was proposed first followed by a secondary surgical curettage. After 4 years' follow-up, complete healing was observed with no recurrence of the lesion.

DISCUSSION

Surgical management of aggressive GCTB is risky particularly in localizations involving the sacrum, spine or craniofacial skeleton with a high residual recurrence rate. The use of denosumab to stop tumor progression and facilitate secondary excision surgery is a recent approach that is now well documented in the literature showing promising results with a low rate of side effects.

CONCLUSION

This case of mandibular GCTB is to our knowledge the unique case described in this localization and treated by denosumab neoadjuvant therapy followed by surgery with a 4-year follow-up showing a complete healing.

Mechanism of regulating macrophages/osteoclasts in attenuating wear particle-induced aseptic osteolysis

Joint replacement surgery is the most effective treatment for end-stage arthritis. Aseptic loosening caused by periprosthetic osteolysis is a common complication after joint replacement. Inflammation induced by wear particles derived from prosthetic biomaterials is a major cause of osteolysis. We emphasize that bone marrow-derived macrophages and their fusion-derived osteoclasts play a key role in this pathological process. Researchers have developed multiple intervention approaches to regulate macrophage/osteoclast activation. Aiming at wear particle-induced periprosthetic aseptic osteolysis, this review separately discusses the molecular mechanism of regulation of ROS formation and inflammatory response through intervention of macrophage/osteoclast RANKL-MAPKs-NF-κB pathway. These molecular mechanisms regulate osteoclast activation in different ways, but they are not isolated from each other. There is also a lot of crosstalk among the different mechanisms. In addition, other bone and joint diseases related to osteoclast activation are also briefly introduced. Therefore, we discuss these new findings in the context of existing work with a view to developing new strategies for wear particle-associated osteolysis based on the regulation of macrophages/osteoclasts.

The Role of Denosumab in the Treatment of Primary Tumors of Bone

Many hand surgeons treat benign bone tumors without referral to orthopedic oncologists. However, there have been considerable advances in medical therapy for some of these tumors, with which hand surgeons may not be as familiar. This review focuses on the mechanism and uses of denosumab in the treatment of benign tumors of bone. Although the hand surgeon may not be directly prescribing this therapy, they are often the only physician treating the patient for these conditions. As such, awareness regarding the use of this therapy in reducing pain, decreasing tumor volume, and treatment of potential lung metastases is critical to those taking on these cases without the support of an orthopedic oncologist. This article aims to familiarize hand surgeons with denosumab to help promote knowledge of this therapeutic option and the potential role of this medication in the treatment of primary bone tumors in the hand.

Establishment and characterization of two novel patient-derived cell lines from giant cell tumor of bone

Giant cell tumor of bone (GCTB) is a rare bone tumor with osteolytic features, composed of stromal cells with a monotonous appearance, macrophages, and osteoclast-like giant cells. GCTB is commonly associated with a pathogenic mutation in the H3-3A gene. While complete surgical resection is the standard cure for GCTB, it often results in local recurrence and, rarely, metastasis. Thus, an effective multidisciplinary treatment approach is necessary. Although patient-derived cell lines is an essential tool for investigating novel treatment strategies, there are only four GCTB cell lines available in public cell banks. Therefore, this study aimed to establish novel GCTB cell lines and successfully created NCC-GCTB6-C1 and NCC-GCTB7-C1 cell lines from two patients' surgically removed tumor tissues. These cell lines exhibited H3-3A gene mutations, consistent proliferation, and invasive properties. After characterizing their behaviors, we performed high-throughput screening of 214 anti-cancer drugs for NCC-GCTB6-C1 and NCC-GCTB7-C1 and integrated their screening data with those of NCC-GCTB1-C1, NCC-GCTB2-C1, NCC-GCTB3-C1, NCC-GCTB4-C1, and NCC-GCTB5-C1 that we previously established. We identified histone deacetylase inhibitor romidepsin as a possible treatment for GCTB. These findings suggest that NCC-GCTB6-C1 and NCC-GCTB7-C1 could be valuable tools for preclinical and basic research on GCTB.

Case Report: Unresectable pulmonary metastases of a giant cell tumor of bone treated with denosumab: a case report and review of literature

Giant cell tumors of bone (GCTB) sometimes metastasize to distant organs. In this case report, we present pulmonary metastases of GCTB mimicking malignancies. A 49-year-old man underwent two surgical treatments for a GCTB of the right proximal radius. At the time of the second surgery, no lesions were observed on chest radiography. Three years after surgery, the patient presented with cough and dyspnea, and chest radiography and computed tomography (CT) revealed multiple lung nodules. Positron emission tomography/CT revealed a high accumulation of 18F-fluoro-2-deoxy-D-glucose (18F-FDG) in multiple lesions. Based on the rapid growth and accumulation of 18F-FDG, a metastatic malignant tumor was suspected. CT-guided needle biopsy was performed, and the histology showed proliferation of spindle cells and multinuclear giant cells without malignant changes. Denosumab was administered because multiple lung lesions were unresectable. One month after denosumab treatment, CT showed marked shrinkage of the lesions, and the symptoms significantly improved. Eighteen months after the initial treatment with denosumab, the patient had no symptoms or tumor growth. Although its long-term efficacy and safety remain unclear, denosumab may be a treatment option for patients with unresectable pulmonary GCTB.

Current therapies and future prospective for locally aggressive mesenchymal tumors

Locally aggressive mesenchymal tumors comprise a heterogeneous group of soft tissue and bone tumors with intermediate histology, incompletely understood biology, and highly variable natural history. Despite having a limited to absent ability to metastasize and excellent survival prognosis, locally aggressive mesenchymal tumors can be symptomatic, require prolonged and repeat treatments including surgery and chemotherapy, and can severely impact patients' quality of life. The management of locally aggressive tumors has evolved over the years with a focus on minimizing morbid treatments. Extensive oncologic surgeries and radiation are pillars of care for high grade sarcomas, however, play a more limited role in management of locally aggressive mesenchymal tumors, due to propensity for local recurrence despite resection, and the risk of transformation to a higher-grade entity following radiation. Patients should ideally be evaluated in specialized sarcoma centers that can coordinate complex multimodal decision-making, taking into consideration the individual patient's clinical presentation and history, as well as any available prognostic factors into customizing therapy. In this review, we aim to discuss the biology, clinical management, and future treatment frontiers for three representative locally aggressive mesenchymal tumors: desmoid-type fibromatosis (DF), tenosynovial giant cell tumor (TSGCT) and giant cell tumor of bone (GCTB). These entities challenge clinicians with their unpredictable behavior and responses to treatment, and still lack a well-defined standard of care despite recent progress with newly approved or promising experimental drugs.

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.

The diverse landscape of dermatologic toxicities of non-immune checkpoint inhibitor monoclonal antibody-based cancer therapy

BACKGROUND

Since their first approval 25 years ago, monoclonal antibodies (mAbs) have become important targeted cancer therapeutics. However, dermatologic toxicities associated with non-immune checkpoint inhibitor (non-ICI) mAbs may complicate the course of cancer treatment. Data on the incidence and types of these reactions are limited.

METHODS

A comprehensive review was conducted on dermatologic toxicities associated with different classes of non-ICI mAbs approved for treatment of solid tumors and hematologic malignancies. The review included prospective Phase 1, 2, and 3 clinical trials; retrospective literature reviews; systematic reviews/meta-analyses; and case series/reports.

RESULTS

Dermatologic toxicities were associated with several types of non-ICI mAbs. Inflammatory reactions were the most common dermatologic toxicities, manifesting as maculopapular, urticarial, papulopustular/acneiform, and lichenoid/interface cutaneous adverse events (cAEs) with non-ICI mAbs. Immunobullous reactions were rare and a subset of non-ICI mAbs were associated with the development of vitiligo cAEs.

CONCLUSION

Dermatologic toxicities of non-ICI mAbs are diverse and mostly limited to inflammatory reactions. Awareness of the spectrum of the histopathologic patterns of cAE from non-ICI mAbs therapy is critical in the era of oncodermatology and oncodermatopathology.

Diffuse Pulmonary Metastases at Presentation of Giant Cell Tumor of Bone: A Case Report and Synthesis of Literature

CASE

We present a 23-year-old man with acute-on-chronic shoulder pain with an aggressive-appearing, destructive lesion of the left proximal humerus and diffuse lung metastases. Biopsy revealed conventional giant cell tumor of bone (GCTB) without sarcomatous differentiation, treated with resection and proximal humerus reconstruction. Without systemic treatment, his pulmonary metastases demonstrated modest spontaneous regression, with no impairment of pulmonary function.

CONCLUSIONS

Although GCTB is known to metastasize to lungs, these deposits most commonly follow local recurrence. We describe a young adult with diffuse pulmonary nodules at initial presentation, although still following an indolent clinical course without the need for additional systemic therapy.

A systematic review of multicentric giant cell tumour with the presentation of three cases at long-term follow-up

Aims

We performed a systematic literature review to define features of patients, treatment, and biological behaviour of multicentric giant cell tumour (GCT) of bone.

Methods

The search terms used in combination were “multicentric”, “giant cell tumour”, and “bone”. Exclusion criteria were: reports lacking data, with only an abstract; papers not reporting data on multicentric GCT; and papers on multicentric GCT associated with other diseases. Additionally, we report three patients treated under our care.

Results

A total of 52 papers reporting on 104 patients were included in the analysis, with our addition of three patients. Multicentric GCT affected predominantly young people at a mean age of 22 years (10 to 62), manifesting commonly as metachronous tumours. The mean interval between the first and subsequent lesions was seven years (six months to 27 years). Synchronous lesions were observed in one-third of the patients. Surgery was curettage in 63% of cases (163 lesions); resections or amputation were less frequent. Systemic treatments were used in 10% (n = 14) of patients. Local recurrence and distant metastases were common.

Conclusion

Multicentric GCT is rare, biologically aggressive, and its course is unpredictable. Patients with GCT should be followed indefinitely, and referred promptly if new symptoms, particularly pain, emerge. Denosumab can have an important role in the treatment. Cite this article: Bone Joint J 2022;104-B(12):1352–1361.

Tetrandrine inhibits RANKL-induced osteoclastogenesis by promoting the degradation of TRAIL

Background

Tetrandrine, a bisbenzylisoquinoline (BBI) alkaloid extracted from Stephania tetrandra (S. Moore), and is widely used in several diseases such as tuberculosis, hyperglycemia, malaria, and tumors. Tetrandrine was recently shown to prevent bone loss in ovariectomized mice. However, the specific mechanism underlying osteoclastogenesis inhibition remains unclear.

Methods

Tetrandrine’s cytotoxicity to cells was determined using the Cell Counting Kit-8 assay. Tartrate-resistant acid phosphatase staining, immunofluorescence and bone resorption assay were performed to evaluate osteoclasts’ differentiation and absorption capacity. The bone-forming capacity was assessed using alkaline phosphatase and Alizarin red S staining. qPCR and Western blotting were applied to assess the related genes and protein expression. Tetrandrine’s impact on TRAIL was demonstrated through a co-immunoprecipitation assay. Animal experiments were performed for the detection of the therapeutic effect of Tetrandrine on osteoporosis.

Results

Tetrandrine attenuated RANKL-induced osteoclastogenesis and decreased the related gene expression. The co-immunoprecipitation assay revealed that Tetrandrine administration accelerated the ubiquitination of TNF-related apoptosis-inducing ligand (TRAIL), which was subsequently degraded. Moreover, TRAIL overexpression was found to partially reverse the Tetrandrine-induced inhibition of osteoclastogenesis. Meanwhile, Tetrandrine significantly inhibited the phosphorylation of p38, p65, JNK, IKBα and IKKα/β, while the TRAIL overexpression weakened this effect. In addition, Tetrandrine promoted osteogenesis and inhibited the TRAIL expression in osteoblasts. Tetrandrine consistently improved bone destruction by stimulating bone formation and inhibiting bone resorption in an OVX-induced mouse model.

Conclusion

Tetrandrine inhibits RANKL-induced osteoclastogenesis by promoting TRAIL degradation and promotes osteoblast differentiation, suggesting its potential in antiosteopenia pharmacotherapy.

Progress on Denosumab Use in Giant Cell Tumor of Bone: Dose and Duration of Therapy

Giant cell tumor of bone (GCTB) is an aggressive non-cancerous bone tumor associated with risks of sarcoma and metastasis. Once malignancy occurs, the prognosis is generally poor. Surgery remains the main treatment for GCTB. Multidisciplinary management is a feasible option for patients wherein surgical resection is not an option or for those with serious surgery-related complications. Denosumab is an anti-nuclear factor kappa B ligand approved for the treatment of postmenopausal women with osteoporosis, bone metastases, and advanced or inoperable GCTB. However, the guidelines for treating GCTB are unclear; its short-term efficacy and safety in inoperable patients have been demonstrated. Lengthier therapies (high cumulative doses) or pre-operative adjuvant therapy may be associated with severe complications and high local recurrence rates. Short-term administration helps attain satisfactory local control and functionality. As a result, lately, the impact of different doses and lengths of treatment on the efficacy of denosumab in GCTB treatment, the incidence of complications, and recurrence rates have gained attention. The efficacy and safety of denosumab against GCTB, its impact on imaging assessment, related complications, and recurrence of GCTB were previously reviewed. For further research direction, this paper reviews the progress of studies evaluating the impact of the dose and duration of denosumab therapy for GCTB.

Prognostic Value and Quantitative CT Analysis in RANKL Expression of Spinal GCTB in the Denosumab Era: A Machine Learning Approach

The receptor activator of the nuclear factor kappa B ligand (RANKL) is the therapeutic target of denosumab. In this study, we evaluated whether radiomics signature and machine learning analysis can predict RANKL status in spinal giant cell tumors of bone (GCTB). This retrospective study consisted of 107 patients, including a training set (n = 82) and a validation set (n = 25). Kaplan-Meier survival analysis was used to validate the prognostic value of RANKL status. Radiomic feature extraction of three heterogeneous regions (VOIentire, VOIedge, and VOIcore) from pretreatment CT were performed. Followed by feature selection using Selected K Best and least absolute shrinkage and selection operator (LASSO) analysis, three classifiers (random forest (RF), support vector machine, and logistic regression) were used to build models. The area under the curve (AUC), accuracy, F1 score, recall, precision, sensitivity, and specificity were used to evaluate the models' performance. Classification of 75 patients with eligible follow-up based on RANKL status resulted in a significant difference in progression-free survival (p = 0.035). VOIcore-based RF classifier performs best. Using this model, the AUCs for the training and validation cohorts were 0.880 and 0.766, respectively. In conclusion, a machine learning approach based on CT radiomic features could discriminate prognostically significant RANKL status in spinal GCTB, which may ultimately aid clinical decision-making.

Siglec-15 as a New Perspective Therapy Target in Human Giant Cell Tumor of Bone

The main features of a giant cell tumor of bone (GCTB) are frequent recurrence and aggressive osteolysis, which leads to a poor prognosis in patients. Although the treatment methods for a GCTB, such as scraping and resection, effectively inhibit the disease, the tendency toward malignant transformation remains. Therefore, it is important to identify new treatment methods for a GCTB. In this study, we first found high Siglec-15 expression in GCTB tissues, which was significantly associated with Campanacci staging and tumor recurrence. In Spearman's analysis, Siglec-15 expression was significantly correlated with Ki-67 levels in tumor tissues. In vitro, the mRNA and protein levels of Siglec-15 were high in GCTB stromal cells (Hs737. T), and Siglec-15 knockdown inhibited the biological characteristics of GCTB stromal cells. The RNA sequencing results enabled a prediction of the downstream genes by using the Kyoto Encyclopedia of Genes and Genomes (KEGG), Gene Ontology (GO), and MCODE analyses, and the findings showed that CXCL8 was significantly regulated by Siglec-15 and might be a promising downstream target gene of Siglec-15. Therefore, Siglec-15 may be a potential immunotherapy target for a GCTB.

RANKL inhibition for giant cell lesions of the jaw: A retrospective cohort analysis

BACKGROUND

In all giant-cell-rich lesions (GCRL) occurring in bone, a common underlying excessive RANKL expression is held responsible for the osteolytic activity. Apart from giant cell tumour of bone (GCTB), systematic outcome analysis of RANKL inhibition in other GCRL is unavailable. The aim of this study is to assess the efficacy and safety of a 1-year denosumab protocol in giant cell lesions of the jaw (GCLJ).

METHODS

A retrospective cohort study was conducted compromising patients treated with a 1-year protocol of monthly subcutaneously administered 120 mg denosumab. Objective tumour response based on histology and imaging was used to calculate objective tumour response rate, progression-free survival (PFS) and time to progression. Type, severity and frequency of adverse events were recorded in a standardised way to assess safety.

RESULTS

Twenty patients, predominantly female (90%), were included. Fifty-five per cent of lesions were located in the mandible; most classified as aggressive lesions (90%). Thirty-five per cent (7/20) of cases were either recurrent after prior treatment or progressive, while on other drug treatment. Objective tumour response rate was 100% after 12 months of treatment. Median PFS was 50.4 months (95% CI 38.0-62.8) with a cumulative PFS rate of 22.6% (95% CI 1.8-43.4) at 5 years follow-up. Median time to progression was 38.4 months (95% CI 26.0-50.8). Treatment was well tolerated, and none of the patients had to interrupt therapy for toxicity.

CONCLUSION

High-dose denosumab is effective and safe in achieving a complete response in GCLJ within 12 months. The high long-term relapse rate after treatment cessation is the main obstacle for denosumab to become standard treatment for GCLJ.

Rechallenge of denosumab in advanced giant cell tumor of the bone after atypical femur fracture: A case report and review of literature

Giant cell tumor of the bone (GCTB) is a locally aggressive neoplasm where surgery is often curative. However, it can rarely give rise to distant metastases. Currently, the only available active therapeutic option for unresectable GCTB is denosumab, an anti-RANKL monoclonal antibody that dampens the aggressive osteolysis typically seen in this disease. For advanced/metastatic GCTB, denosumab should be continued lifelong, and although it is usually well tolerated, important questions may arise about the long-term safety of this drug. In fact, uncommon but severe toxicities can occur and eventually lead to denosumab discontinuation, such as atypical fracture of the femur (AFF). The optimal management of treatment-related AFF is a matter of debate, and to date, it is unknown whether reintroduction of denosumab at disease progression is a clinically feasible option, as no reports have been provided so far. Hereinafter, we present a case of a patient with metastatic GCTB who suffered from AFF after several years of denosumab; we describe the clinical features, orthopedic treatment, and oncological outcomes, finally providing the first evidence that denosumab rechallenge after AFF occurrence may be a safe and viable option at GCTB progression.

Outcomes in Bone Giant Cell Tumors Treated With Surgical Resection With and Without Denosumab Injection: A Single-Institution Retrospective Study

Background: Giant cell tumors of the bone (GCTB) are rare, benign, aggressive, recurrent tumors that are most often found at the ends of long bones. They account for 5% of all primary bone tumors and 20% of all benign bone tumors. The clinical features of GCTB include local swelling, pain, and limitations in joint movement. Approximately half of GCTB arise around the knee joint, affecting either the distal femur or proximal tibia. Tissue biopsy reveals an excess of multinucleated giant cells on a stromal cell background, indicating a diagnosis. Intralesional curettage is used to treat GCTB and is associated with minimal disability; however, local recurrence may occur in many patients. Resection and endoprosthetic repair or bone graft reconstruction are often used to treat GCTB near the joint. To our knowledge, there are currently no studies on this topic in the city of Jeddah, where we conducted our study. Our aim was to evaluate the outcome of surgical resection accompanied by denosumab injection compared to that of surgery alone in treating GCTB.

Methods: All cases of GCTB at King Abdulaziz Medical City, Jeddah, between January 2008 and December 2018, that fulfilled the inclusion and exclusion criteria were included. All cases of GCTB in the pre-specified period were classified as surgical resection with denosumab injection or surgical resection alone. The outcomes of the two modalities were compared. Recurrence was investigated in patients belonging to both the groups.

Results: Twenty-six cases that met the inclusion criteria were included in the study and the data were analyzed. The subjects were divided into two groups: denosumab and surgery (n = 7) and surgery alone (n = 19). Patients treated with denosumab and surgery had a higher recurrence rate (57%); however, the difference was not significant (p = 0.407).

Conclusion: Our study showed that when comparing local recurrence after curettage in patients treated with denosumab and patients who did not receive it, preoperative denosumab therapy was associated with an increased incidence of local recurrence. We recommend a systematic review that can include more studies in this field to acquire more definitive results regarding this topic.

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.

Radiologic and clinical changes after denosumab treatment for giant cell tumors of the mobile spine: a quantitative study

Objectives

To analyze the radiologic and clinical changes after denosumab treatment in patients with giant cell tumors (GCTs) in the mobile spine.

Methods

Clinical data and images by computed tomography and magnetic resonance imaging at a single center were retrospectively reviewed before and after denosumab treatment.

Results

Pre- and post-treatment data from 24 patients were evaluated. On imaging, marginal ossification and/or bone formation was observed in 22 patients (91.7%). The median maximum diameter of the GCT reduced from 52.5 to 48.2 mm (p < 0.001), and the mean proportion of tumor to spinal canal area decreased from 36.8 to 18.5% (p < 0.001). Out of six patients with compression, three patients (50%) showed no compression after treatment. The signal intensity (SI) ratio between the solid part of the tumor and the normal spinal cord on T2-weighted MR images was 0.77 ± 0.22 and decreased to 0.58 ± 0.22 (p = 0.001). On clinical symptoms, the mean visual analog scale scores were reduced from 5.3 to 2.0 (p < 0.001) and the Karnofsky Performance Scale scores increased from a median of 65 to 80 (p < 0.001). Post-treatment, performance scores improved in eight patients (33.3%) (p = 0.003), and the neurological function of four patients improved according to Frankel grade (p = 0.046).

Conclusions

Bone formation, tumor reduction, regression of epidural lesion and the decrease in SI ratio on T2-weighted image should be considered as the effectiveness of denosumab in the treatment of spinal GCT. In clinical application, denosumab can relieve pain, improve neurological function, and improve the quality of life of spinal GCT patients.

Primary Benign Tumors of the Spinal Canal

Benign tumors that grow in the spinal canal are heterogeneous neoplasms with low incidence; from these, meningiomas and nerve sheath tumors (neurofibromas and schwannomas) account for 60%-70% of all primary spinal tumors. Benign spinal canal tumors provoke nonspecific clinical manifestations, mostly related to the affected level of the spinal cord. These tumors present a challenge for the patient and healthcare professionals, for they are often difficult to diagnose and the high frequency of posttreatment complications. In this review, we describe the epidemiology, risk factors, clinical features, diagnosis, histopathology, molecular biology, and treatment of extramedullary benign meningiomas, osteoid osteomas, osteoblastomas, aneurysmal bone cysts, osteochondromas, neurofibromas, giant cell tumors of the bone, eosinophilic granulomas, hemangiomas, lipomas, and schwannomas located in the spine, as well as possible future targets that could lead to an improvement in their management.

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.

Tenosynovial giant cell tumors (TGCT): molecular biology, drug targets and non-surgical pharmacological approaches

INTRODUCTION

Tenosynovial giant cell tumor (TGCT) is a mono-articular, benign or locally aggressive and often debilitating neoplasm. Systemic therapies are becoming part of the multimodal armamentarium when surgery alone will not confer improvements. Since TGCT is characterized by colony-stimulating factor-1 (CSF1) rearrangements, the most studied molecular pathway is the CSF1 and CSF1 receptor (CSF1R) axis. Inhibiting CSF1-CSF1R interaction often yields considerable radiological and clinical responses; however, adverse events may cause treatment discontinuation because of an unfavorable risk-benefit ratio in benign disease. Only Pexidartinib is approved by the US FDA; however, the European Medicines Agency has not approved it due to uncertainties on the risk-benefit ratio. Thus, there is a need for safer and effective therapies.

AREAS COVERED

Light is shed on disease mechanisms and potential drug targets. The safety and efficacy of different systemic therapies are evaluated.

EXPERT OPINION

The CSF1-CSF1R axis is the principal drug target; however, the effect of CSF1R inhibition on angiogenesis and the role of macrophages, which are essential in the postoperative course, needs further elucidation. Systemic therapies have a promising role in treating mainly diffuse-type, TGCT patients who are not expected to clinically improve from surgery. Future drug development should focus on targeting neoplastic TGCT cells.

Neuregulin 1 (NRG1) fusion-positive high-grade spindle cell sarcoma: A distinct group of soft tissue tumors with metastatic potential

Neuregulin 1 (NRG1) is an epidermal growth factor (EGF)-like ligand that activates receptor tyrosine kinases of the ErbB family of receptors. NRG1 gene fusions, which are rare (<1%) but recurrent events in solid tumors, are an emerging oncogenic driver that is potentially actionable using ErbB-targeted tyrosine kinase inhibitors. Largely characterized only in carcinomas, we describe three cases of NRG1-rearranged sarcomas. The patients were all female, aged 32-47 years old. Two cases were deep-seated tumors in the lower extremities (right thigh and calf); one case presented as a uterine mass. The tumors measured 9-11.5 cm in the greatest dimensions. Histologically, all three tumors were high-grade spindle cell sarcomas composed of monomorphic spindle cells arranged in interlacing fascicles. The tumor cells were set in the loose collagenous stroma with branching, curvilinear thin-walled vasculature in the background. Cytologically, the neoplastic cells displayed ovoid to fusiform nuclei with finely stippled chromatin, inconspicuous nucleoli, scant to moderate clear to eosinophilic cytoplasm, occasional cytoplasmic vacuoles, and elongated cytoplasmic processes. Mitotic activity was elevated (> 20/10 high power fields) and tumor necrosis was present. None of the tumors expressed lineage-specific immunophenotypical markers. Targeted RNA-sequencing uncovered gene fusions involving NRG1 and the 5' untranslated regions of PPHLN1, HMBOX1, or MTUS1. In all cases, the C-terminal EGF-like domain of NRG1 was preserved in the predicted chimeric protein product. All three patients developed metastatic disease within 2 years from initial presentation and were alive with disease at last follow-up (mean follow-up period = 19 months). In conclusion, we present the first case series of NRG1-rearranged sarcomas characterized by high-grade fascicular spindle cell morphology, non-specific immunoprofile, and aggressive clinical behavior. Further studies are needed to determine whether this distinct subgroup of spindle cell sarcomas are amenable to targeted therapies.

Current management of giant-cell tumor of bone in the denosumab era

Giant-cell tumor of bone is a rare, locally aggressive and rarely metastasizing primary bone tumor. The mainstay of treatment remains controversial and is decided by the balance between adequate surgical margin and sufficient adjacent joint function. Although curettage with a high-speed burr and local adjuvants can maintain normal joint function, many reports have revealed a high local recurrence rate. Conversely, en bloc resection and reconstruction with prostheses for highly aggressive lesions have reportedly lower local recurrence rates and poorer functional outcomes. Denosumab-a full human monoclonal antibody that inhibits receptor activator of nuclear factor-kappa β ligand-was approved by the Food and Drug Authority in 2013 for use in surgically unresectable or when resection is likely to result in severe morbidity for skeletally mature adolescents and adults with giant-cell tumor of bone. However, subsequent studies have suggested that the local recurrence rate would be increased by preoperative use of denosumab. In systematic reviews of the local recurrence rate after preoperative use of denosumab, conclusions vary due to the small sample sizes of the studies reviewed. Therefore, controversy regarding the treatment of giant-cell tumor of bone is ongoing. Here, this review elucidates the management of giant-cell tumor of bone, especially with the local adjuvant and neoadjuvant use of denosumab, and presents the current, evidence-based treatment for giant-cell tumor of bone.

Giant Cell Tumor of Bone: A Single Center Study of 115 cases

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Giant cell tumor of bone (GCTB) is a rarely metastasizing, locally aggressive tumor.

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GCTB recurs frequently after intralesional curettage.

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Denosumab is a potential neoadjuvant treatment option for borderline resectable lesions.

Background

Giant cell tumor of bone (GCTB) is a locally aggressive bone tumor that represents about 4–5% of all primary bone tumors. It is characterized by aggressive growth, possible recurrence after surgical treatment and, in rare cases, metastasis. Surgical management is the primary treatment and may include intralesional curettage with adjuvants or, in rare cases, wide resection. In recent years the monoclonal antibody denosumab has been introduced as a potential (neo-)adjuvant systemic treatment option for patients with borderline resectable or unresectable lesions. Currently several studies reported that the use of denosumab prior to curettage possibly increase the risk of local recurrence.

Methods

In this retrospective study we reviewed 115 cases of GCT with a mean follow-up of 65.6 (24–404) months who underwent a surgical treatment with or without preoperative denosumab therapy in our institution. Potential risk factors for LR and complications were analyzed.

Results

The study includes 47 male (40.9%) and 68 female (59.1%) patients with a mean age of 33.9 (10–77) years and a mean follow-up of 65.6 (24–404) months. Denosumab was used in 33 (28.7%) cases, in 14 cases (12.2%) in a neoadjuvant setting and in 17 cases preoperatively before re-curettage (14.8%) after LR. In 105 cases (91.3%) an intralesional curettage was performed. The overall LR rate was 47.8% (55 cases). Patients who underwent intralesional curettage and bone cement augmentation without neoadjuvant denosumab treatment had LR in 42.2% (38/90) of the cases. Patients who underwent neoadjuvant denosumab treatment prior to curettage had LR in 28.6% (4/14). Re-recurrence was frequent in patients with neoadjuvant denosumab treatment who had LR after initial curettage (50%, 8/16). After wide resection and endoprosthetic replacement one case (20%) of local recurrence was detectable (1/5 cases).

Conclusions

GCTB recurs frequently after intralesional curettage and cement augmentation. While denosumab is a potential (neo-)adjuvant treatment option that might be used for lesions that are difficult to resect, surgeons should be aware that LR is still frequent.

Study of imaging changes following preoperative denosumab for giant cell tumor of bone

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The preoperative application of denosumab can reduce tumor blood supply.

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The decrease of blood supply was the most significant in the initial stage of treatment.

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It is not recommended to apply denosumab long before surgical treatment.

Background

The changes in the characteristics of the tumor blood supply of giant cell tumor of bone over time after treatment with denosumab remain unclear. The purpose of this study was to evaluate the change in the blood supply imaging characteristics of giant cell tumor of bone after preoperative denosumab treatment and to provide evidence for evaluating the reasonable time for preoperative treatment.

Methods

A total of 59 patients with giant cell tumor of bone who were treated in our hospital from 2014 to 2019 were enrolled in the study. All patients underwent enhanced CT examination of the tumor site before denosumab treatment and every month after treatment. The plain CT value and enhanced CT value of the tumor were measured, and the CT enhancement rate of the tumor was calculated. The change in the CT enhancement rate of the tumor over time after denosumab treatment was analyzed.

Results

The average tumor enhancement rates were 2.14 (1.22–4.05), 1.60 (1.12–2.53), 1.38 (1.02–2.24), and 1.25 (1–2.11) before denosumab treatment and one month, three months, and six months after treatment, respectively. After denosumab treatment, the average monthly CT enhancement rate decreased as follows: 0.54 (25.2%) in the first month, 0.11 (5.15%) in the second to third months, and 0.04 (1.87%) in the fourth to sixth months. The tumor enhancement rate was no longer significantly reduced three months post-treatment. There was a significant correlation between the reduction in the CT enhancement rate and the initial CT enhancement rate (P = 0.000).

Conclusion

The preoperative application of denosumab can reduce tumor blood supply. The decrease in the blood supply is the most significant in the initial stage of treatment. Following treatment, the decrease in the blood supply gradually reduces over time. Therefore, for the purpose of reducing intra-operative bleeding and facilitating surgery, application of denosumab treatment is not recommended more than three months before surgery.

LONG-TERM USE OF DENOSUMAB IN GIANT CELL TUMORS AND VERTEBRAL ANEURYSMAL BONE CYSTS

ABSTRACT Introduction: Denosumab is a human monoclonal antibody that binds to the receptor activator of nuclear factor kB (RANKL), it is used in the treatment of Osteoporosis. The Giant Cell Tumor (GCT) and the Aneurysmal Bone Cyst (ABC) use the same RANKL, and for this reason this drug began to be used for its treatment. There is consensus on the use, dose-time and 12-month duration for Denosumab treatment of GCT. Not so for ABC. In unresectable, disabling or recurrent tumors, its use could be for life. The adverse events of the habitual use of the drug are known, but it is not known if these increase with time. The objective of the present work is to identify the possible adverse events of treatment with Denosumab for more than 12 months. Material and Method: Series of cases with a diagnosis of GCT or ABC in spine, treated with Denosumab for more than 12 months. Adverse events are: arthralgia, fatigue, spinal pain, pain in extremities, headache, hypokalaemia, hypocalcemia, osteonecrosis of the jaw, malignant transformation, pathological fractures. Results: Eight patients, 6 TCG and 2 ABC, with a mean age at diagnosis of 25,6 years; presenting a mean treatment of 4.18 years (range 1.7 - 8.7). Of 6 operated patients, 4 had recurrence (2 to 36 months after surgery). One patient had to suspend treatment due to necrosis of the jaw, another hypocalcemia, both returned to treatment when stabilized. Conclusions: A minor adverse event (hypocalcemia) and a major adverse event (jaw bone necrosis) were observed. Level of Evidence IV; Original.

OUP accepted manuscript

Background

Methods

Results

Conclusions

Successful treatment with denosumab for pelvic fibrous dysplasia: A case report and review of the literature

RATIONALE

Fibrous dysplasia is a rare disorder that results in fractures, pain, and disability and can affect any bone in the body. The treatment of symptomatic fibrous dysplasia is determined based on the affected bones. Although some lesions are often too extensive for surgical procedures, there are currently no effective or recommended medical treatments available for them.

PATIENT CONCERNS

A 27-year-old woman developed right buttock pain and was diagnosed with a bone tumor in the right ilium. Clinical images revealed an expansive osteolytic lesion with thinning of the cortex and cystic change from the acetabulum to the sacroiliac joint.

DIAGNOSIS

An incisional biopsy was performed, and the lesion was diagnosed as cystic fibrous dysplasia. Occasional osteoclast-like giant cells and woven bone were observed. The patient had no evidence of polyostotic lesions or findings of McCune-Albright syndrome. Biochemical blood test results showed no obvious abnormal values, except for an increase in serum tartrate-resistant acid phosphatase 5b to 459 mU/dL.

INTERVENTIONS

Since surgical treatment appeared to be challenging, she was treated with denosumab with decreased dose-intensity schedules.

OUTCOMES

The administration of denosumab caused osteosclerosis within the lesion, resulting in the elimination of bone pain. The patient received denosumab treatment for 18 months. Pain relief and lesion radiodensity were maintained for 9 months after denosumab discontinuation. The serum level of tartrate-resistant acid phosphatase 5b was measured to monitor the response to denosumab, which was suppressed during denosumab treatment.

LESSONS

We described successful denosumab treatment in a patient with cystic fibrous dysplasia (FD) who maintained efficacy for 9 months after treatment. Although the use of denosumab in fibrous dysplasia is currently off-label, our experience with this patient supports the potential of denosumab therapy for patients for whom surgical treatment is challenging.

Intralesional nerve-sparing surgery versus non-surgical treatment for giant cell tumor of the sacrum

Background

There is no standard treatment for giant cell tumors of the sacrum. We compared the outcomes and complications in patients with sacral giant cell tumors who underwent intralesional nerve-sparing surgery with or without (neo-) adjuvant therapies versus those who underwent non-surgical treatment (denosumab therapy and/or embolization).

Methods

We retrospectively investigated 15 cases of sacral giant cell tumors treated at two institutions between 2005 and 2020. Nine patients underwent intralesional nerve-sparing surgery with or without (neo-) adjuvant therapies, and six patients received non-surgical treatment. The mean follow-up period was 85 months for the surgical group (range, 25–154 months) and 59 months (range, 17–94 months) for the non-surgical group.

Results

The local recurrence rate was 44% in the surgical group, and the tumor progression rate was 0% in the non-surgical group. There were two surgery-related complications (infection and bladder laceration) and three denosumab-related complications (apical granuloma of the tooth, stress fracture of the sacroiliac joint, and osteonecrosis of the jaw). In the surgical group, the mean modified Biagini score (bowel, bladder, and motor function) was 0.9; in the non-surgical group, it was 0.5. None of the 11 female patients became pregnant or delivered a baby after developing a sacral giant cell tumor.

Conclusions

The cure rate of intralesional nerve-sparing surgery is over 50%. Non-surgical treatment has a similar risk of complications to intralesional nerve-sparing surgery and has better functional outcomes than intralesional nerve-sparing surgery, but patients must remain on therapy over time. Based on our results, the decision on the choice of treatment for sacral giant cell tumors could be discussed between the surgeon and the patient based on the tumor size and location.

Denosumab Does Not Decrease Local Recurrence in Giant Cell Tumor of Bone Treated With En Bloc Resection

We performed a systematic analysis of existing studies to determine whether preoperative denosumab reduces the risk of local recurrence for patients with giant cell tumor of bone treated with en bloc resection and to address the optimal duration of preoperative denosumab with respect to the risk of local recurrence after en bloc resection. Denosumab did not decrease the risk of local recurrence after en bloc resection; the proportion of patients with local recurrence was 3.6% (2 of 56) in the en bloc resection with preoperative denosumab group vs 14.2% (40 of 280) in the en bloc resection alone group, with an overall pooled odds ratio of 0.76 (P=.67). Meta-regression models revealed no association between the duration of preoperative denosumab and the odds of local recurrence after en bloc resection (P=.83). Administration of denosumab for 3 months before en bloc resection is appropriate for sufficient bone hardening to reduce tumor cell spillage and does not result in denosumab-related complications. [Orthopedics. 2021;44(6):326-332.].

Metastasectomy Versus Non-Metastasectomy for Giant Cell Tumor of Bone Lung Metastases

Approximately 2% to 9% of giant cell tumor of bone (GCTB) metastasizes systemically, mainly to the lungs. The biological behaviors and clinical courses of lung metastases are difficult to predict, and their treatment recommendations vary, including metastasectomy and non-metastasectomy with chemotherapy (denosumab, interferon-alfa, bisphosphonates), with radiation therapy, or with observation alone. However, it is unclear whether metastasectomy for GCTB lung metastases decreases the mortality rate of these patients. Therefore, the authors performed this systematic review to compare metastasectomy and non-metastasectomy for GCTB patients with operable lung metastasis. Of the 919 relevant studies, 16 studies (138 patients) were included for analysis; 61.6% of patients had metastasectomy and 38.4% had non-metastasectomy. Analysis showed that mortality rates were similar for the patients who had metastasectomy compared with those who did not; the proportion of patients who died of disease was 7.1% in the metastasectomy group and 17.0% in the non-metastasectomy group, with an overall pooled odds ratio of 0.64 (P=.36). Therefore, physicians should reconsider the potential risks and benefits of metastasectomy for patients with GCTB and lung metastasis, because metastasectomy does not reduce the mortality rate in these patients. [Orthopedics. 2021;44(6):e707-e712.].

Comparison of Denosumab and Zoledronic acid as neoadjuvant therapy in patients with giant cell tumor of bone

OBJECTIVES

Both Zoledronic acid and denosumab have been utilized in neo-adjuvant setting for facilitating surgery and downsizing the lesion in Giant cell tumor (GCT). This study is aimed at comparing Zoledronic acid and Denosumab, when used in neo-adjuvant setting, in terms of radiological and clinical outcomes in GCT undergoing surgical intervention.

PATIENTS AND METHODS

Patients undergoing surgical intervention for GCT who received either denosumab or Zoledronic acid as neoadjuvant agents were retrospectively analyzed for reduction in tumor load radiologically, change in surgical plan after therapy, facilitation of surgery, therapy related complications, cost of treatment, rate of local recurrence and clinical outcomes.

RESULTS

Twenty patients received denosumab and 19 patients received Zoledronic acid as neoadjuvant agent. There was no significant difference in radiological outcomes, facilitation of surgery and clinical outcomes at end of follow-up. Zoledronic acid group had lower number of recurrences, however, not statistically significant. Therapy with Zoledronic acid was significantly cheaper (p = 0.001).

CONCLUSION

Zoledronic acid is a cheaper alternative to denosumab in terms of solidification of lesion, reducing recurrence rates and improving clinical outcomes. Larger prospective studies required to further delineate this outcome with Zoledronic acid.

Spontaneous Regression of Brown Tumor in a Patient Treated With Peritoneal Dialysis

A 52-year-old man, with a history of diabetic nephropathy and renal cancer, had been treated with peritoneal dialysis for four months before consulting our hospital. At the time of imaging evaluation, three years after surgery for renal cancer, fluorodeoxyglucose accumulation was found at the distal metaphysis of the left radius. After the biopsy, he was diagnosed with giant cell tumor of bone (GCTB), and surgery was scheduled. However, osteogenesis was observed in the images retaken before surgery. It was found that his intact parathyroid hormone level had been abnormally high four months prior to his visit to us but had subsequently normalized. The tissue obtained by re-biopsy revealed osteogenesis with the disappearance of multinucleated giant cells, suggesting a brown tumor (BT). The tumor was thought to have been caused by secondary hyperparathyroidism (HPT) associated with peritoneal dialysis. When osteolytic lesions mimicking GCTB are found, the possibility of BT should be considered based on comorbidities and clinical information.

DUSP6 expression is associated with osteoporosis through the regulation of osteoclast differentiation via ERK2/Smad2 signaling

Osteoporosis-related fractures, such as femoral neck and vertebral fractures, are common in aged people, resulting in increased disability rate and health-care costs. Thus, it is of great importance to clarify the mechanism of osteoclast-related osteoporosis and find effective ways to avoid its complication. In this study, gene expression profile analysis and real-time polymerase chain reaction revealed that DUSP6 expression was suppressed in human and mice osteoporosis cases. In vitro experiments confirmed that DUSP6 overexpression prevented osteoclastogenesis, whereas inhibition of DUSP6 by small interference RNA or with a chemical inhibitor, (E/Z)-BCI, had the opposite effect. (E/Z)-BCl significantly accelerated the bone loss process in vivo by enhancing osteoclastogenesis. Bioinformatics analyses and in vitro experiments indicated that miR-181a was an upstream regulator of DUSP6. Moreover, miR-181a positively induced the differentiation and negatively regulated the apoptosis of osteoclasts via DUSP6. Furthermore, downstream signals by ERK2 and SMAD2 were also found to be involved in this process. Evaluation of ERK2-deficiency bone marrow-derived macrophages confirmed the role of ERK2 signaling in the DUSP6-mediated osteoclastogenesis. Additionally, immunoprecipitation assays confirmed that DUSP6 directly modified the phosphorylation status of SMAD2 and the subsequent nuclear transportation of NFATC1 to regulate osteoclast differentiation. Altogether, this study demonstrated for the first time the role of miRNA-181a/DUSP6 in the progression of osteoporosis via the ERK2 and SMAD2 signaling pathway. Hence, DUSP6 may represent a novel target for the treatment of osteoclast-related diseases in the future.

What's new in musculoskeletal oncology

We reviewed the recent literature related to primary musculoskeletal tumors and metastatic bone tumors. With regard to primary bone tumors, computer navigation systems and three-dimensional-printed prostheses seem to be new treatment options, especially in challenging anatomical locations, such as the sacrum and pelvis. Regarding the treatment of giant cell tumor of bone, recent studies have suggested that denosumab administration is related to a higher local recurrence rate following curettage, but a lower local recurrence rate following en bloc resection. In addition, there was no difference in the local recurrence rate at five years after surgery between short-term and long-term denosumab therapy. With regard to soft tissue tumors, percutaneous cryoablation appears to be a new treatment option for extra-abdominal desmoid tumors, with encouraging results. Regarding soft tissue sarcomas, a negative surgical margin of < 1 mm is sufficient to control local recurrence. Pexidartinib seems to be a promising systemic therapy for the treatment of tenosynovial giant cell tumors for which surgery is not expected to improve the function of the affected limb. Finally, the life expectancy of patients is the most important factor in determining the optimal surgical procedure for patients with impending or pathological fractures of the long bone due to metastatic bone tumors. Elevated C-reactive protein level was found to be an independent poor prognostic factor at 1 year after surgery for long bone metastases.

Current Concepts in the Treatment of Giant Cell Tumors of Bone

Simple Summary

According to the 2020 World Health Organization classification, a giant cell tumor of bone is an intermediate malignant bone tumor. Denosumab treatment before curettage should be avoided due to the increased risk of local recurrence. Administration of denosumab before en bloc resection of the giant cell tumors of the pelvis and spine facilitates en bloc resection. Nerve-sparing surgery after embolization is a possible treatment for giant cell tumors of the sacrum. Denosumab therapy with or without embolization is indicated for inoperable giant cell tumors of the pelvis, spine, and sacrum. A wait-and-see approach is recommended for lung metastases at first, then denosumab should be administered to the growing lesions. Radiotherapy is not recommended owing to the risk of malignant transformation. Local recurrence after 2 years or more should be indicative of malignant transformation. This review summarizes the treatment approaches for non-malignant and malignant giant cell tumors of bone.

Abstract

The 2020 World Health Organization classification defined giant cell tumors of bone (GCTBs) as intermediate malignant tumors. Since the mutated H3F3A was found to be a specific marker for GCTB, it has become very useful in diagnosing GCTB. Curettage is the most common treatment for GCTBs. Preoperative administration of denosumab makes curettage difficult and increases the risk of local recurrence. Curettage is recommended to achieve good functional outcomes, even for local recurrence. For pathological fractures, joints should be preserved as much as possible and curettage should be attempted. Preoperative administration of denosumab for pelvic and spinal GCTBs reduces extraosseous lesions, hardens the tumor, and facilitates en bloc resection. Nerve-sparing surgery after embolization is a possible treatment for sacral GCTBS. Denosumab therapy with or without embolization is indicated for inoperable pelvic, spinal, and sacral GCTBs. It is recommended to first observe lung metastases, then administer denosumab for growing lesions. Radiotherapy is associated with a risk of malignant transformation and should be limited to cases where surgery is impossible and denosumab, zoledronic acid, or embolization is not available. Local recurrence after 2 years or more should be indicative of malignant transformation. This review summarizes the treatment approaches for non-malignant and malignant GCTBs.