Denosumab: a new treatment option for giant cell tumor of bone

Total en bloc spondylectomy of thoracic giant cell tumor with secondary aneurysmal bone cyst: case reports and review of literature

Spinal giant cell tumor (GCT) combined with secondary aneurysmal bone cyst (ABC) is a locally aggressive primary bone tumor. Total en bloc spondylectomy has never been reported to treat thoracic GCT combined with secondary ABC. We retrospectively reviewed two cases of spinal GCT combined with secondary ABC. A 41-year-old male patient was presented with back pain due to irregular expansive bone destruction involving the T6 vertebral body and intraspinal space-occupying lesion. Total en bloc spondylectomy of T6 vertebra was performed with good neurological status after the surgery. A 29-year-old female patient was presented with right scapular region pain due to irregular expansive bone destruction involving the T5 vertebral body and intraspinal space-occupying lesion. Total en bloc spondylectomy of T5 vertebra was performed with good neurological status after the surgery. Adjuvant radiation therapy was applied after the surgery without local recurrence at the 12-month or 24-month follow-up. Spinal GCT combined with secondary ABC appears to have a high local recurrence rate. Therefore, total en bloc spondylectomy should be applied to treat thoracic GCT combined with secondary ABC.

Ischiopubic Ramus Resection as Treatment for Giant Cell Tumor of the Bone: Surgical Techniques in Two Clinical Cases

Giant cell tumors (GCTs) of the ischium are rare and often diagnosed at an advanced stage. In fact, there is no defined treatment algorithm to treat this lesion. We present two case reports of Campanacci's stage three ischiopubic GCT confirmed with biopsy. They were effectively treated with excision of the ischiopubic ramus, aggressive curettage, drilling, and phenolization at the margins. The surgery was performed in a gynecological position with an approach over the ischiopubic ramus. Both cases present no recurrence (two and 10-year follow-up), and neither has a significant impact on the quality of life. A thorough plan and surgical technique were essential for the success of this intervention.

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.

Characterization and Treatment of Spinal Tumors

The prevalence of spinal tumors is rare in comparison to brain tumors which encompass most central nervous system tumors. Tumors of the spine can be divided into primary and metastatic tumors with the latter being the most common presentation. Primary tumors are subdivided based on their location on the spinal column and in the spinal cord into intramedullary, intradural extramedullary, and primary bone tumors. Back pain is a common presentation in spine cancer patients; however, other radicular pain may be present. Magnetic resonance imaging (MRI) is the imaging modality of choice for intradural extramedullary and intramedullary tumors. Plain radiographs are used in the initial diagnosis of primary bone tumors while Computed tomography (CT) and MRI may often be necessary for further characterization. Complete surgical resection is the treatment of choice for spinal tumors and may be curative for well circumscribed lesions. However, intralesional resection along with adjuvant radiation and chemotherapy can be indicated for patients that would experience increased morbidity from damage to nearby neurological structures caused by resection with wide margins. Even with the current treatment options, the prognosis for aggressive spinal cancer remains poor. Advances in novel treatments including molecular targeting, immunotherapy and stem cell therapy provide the potential for greater control of malignant and metastatic tumors of the spine.

Evaluating the Optimal Management of Inoperable Giant Cell Tumors of the Spine: A Systematic Review and Meta-Analysis

Simple Summary

Spine giant cell tumors (SGCTs) are intermediate malignant bone tumors, sometimes aggressive and responsible for debilitating axial pain and sensorimotor impairments. Non-surgical therapies, including denosumab, radiotherapy, and selective arterial embolization (SAE), have shown promising results in the treatment of patients with inoperable SGCTs. In this systematic review, we aimed to comprehensively analyze the current literature on denosumab, radiotherapy, and SAE for inoperable SGCTs, comparing treatment outcomes and complications using a random-effect model meta-analysis. We found that all three treatments were equally effective in providing symptom improvement and radiological tumor response, also showing low and comparable rates of treatment-related complications. Patients treated with denosumab showed lower rates of local recurrences and distant metastases.

Abstract

Background: Surgical resection remains the preferred treatment in spine giant cell tumors (SGCTs), but it is not always feasible. Conservative strategies have been studied for inoperable cases. We systematically reviewed the literature on inoperable SGCTs treated with denosumab, radiotherapy or selective arterial embolization (SAE). Methods: PubMed, Scopus, Web-of-Science, Ovid-EMBASE, and Cochrane were searched following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines to include studies of inoperable SGCTs treated with denosumab, radiotherapy or SAE. Treatment outcomes were analyzed and compared with a random-effect model meta-analysis. Results: Among the 17 studies included, 128 patients received denosumab, 59 radiotherapy, and 43 SAE. No significant differences in baseline patient characteristics were found between the three groups. All strategies were equally effective in providing symptom improvement (p = 0.187, I² = 0%) and reduction in tumor volume (p = 0.738, I² = 56.8%). Rates of treatment-related complications were low (denosumab: 12.5%; radiotherapy: 8.5%; SAE: 18.6%) and comparable (p = 0.311, I² = 0%). Patients receiving denosumab had significantly lower rates of local tumor recurrence (10.9%) and distant metastases (0%) compared to patients receiving radiotherapy (30.5%; 8.5%) or SAE (35.6%; 7%) (p = 0.003, I² = 32%; p = 0.002, I² = 47%). Denosumab was also correlated with significantly higher overall survival rates at 18 months (99.2%) and 24 months (99.2%) compared to radiotherapy (91.5%; 89.6%) and SAE (92.5%; 89.4%) (p = 0.019, I² = 8%; p = 0.004, I² = 23%). Mortality was higher in patients receiving SAE (20.9%) or radiotherapy (13.6%) compared to denosumab (0.8%) (p < 0.001), but deaths mostly occurred for unrelated diseases. Conclusions: Denosumab, radiotherapy, and SAE are safe and effective for inoperable SGCTs. Clinical and radiological outcomes are mostly comparable, but denosumab may provide superior tumor control.

Depression and anxiety in recurrent giant cell tumor of bone

Giant cell tumor of bone (GCTB) is a benign neoplasia more frequently encountered in young females. The pathogenic and evolutionary dynamics of the disease is strongly influenced by the presence of depression and cellular mechanisms, especially proinflammatory and immune. Although it is not a malignant tumor, it is often recurrent, which determines a high level of depression, anxiety, and fear of the patients. Cytokine mechanisms, especially through increased tumor necrosis factor alpha (TNFα) and interleukin-6 (IL-6), as well as the involvement of the receptor activator of nuclear factor-kappa B (RANK)–RANK ligand (RANK-L) system, can be correlated with the risk of malignancy. Unfavorable evolution is associated with persistent pain, difficulties of movement and body dysmorphic symptoms. The diagnosis is based mainly on histopathological (HP) assessment. The patients can be treated with pharmacological agents (Denosumab), surgery with tumor excision, reconstruction or osteosynthesis, and radiotherapy. Patients with GCTB require HP and imaging evaluations, especially of relapses, to detect the risk of metastasis or malignancy, simultaneously with psychological and psychiatric monitoring to detect depression, addictive behaviors, and suicide risk. It is necessary to evaluate in a multidisciplinary team to avoid unfavorable oncological and psychiatric developments. Through its clinical, HP, and therapeutic features, GCTB has multiple connections with the psychological and psychopathological dimension.

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.

An Overview of the Derivation and Function of Multinucleated Giant Cells and Their Role in Pathologic Processes

Monocyte lineage cells play important roles in health and disease. Their differentiation into macrophages is crucial for a broad array of immunologic processes that regulate inflammation, neoplasia, and infection. In certain pathologic conditions, such as foreign body reactions and peripheral inflammatory lesions, monocytes fuse to form large, multinucleated giant cells (MGCs). Currently, our knowledge of the fusion mechanisms of monocytes and the regulation of MGC formation and function in discrete pathologies is limited. Herein, we consider the types and function of MGCs in disease and assess the mechanisms by which monocyte fusion contributes to the formation of MGCs. An improved understanding of the cellular origins and metabolic functions of MGCs will facilitate their identification and ultimately the treatment of diseases and disorders that involve MGCs.

Total spondylectomy for Enneking stage III giant cell tumor of the mobile spine

PURPOSE

We reported the surgical outcomes of total en bloc spondylectomy (TES) with intralesional T-saw transpedicular osteotomy in patients with Enneking stage III spinal giant cell tumors (GCTs).

METHODS

The medical records and imaging and pathological studies of 25 consecutive patients with Enneking stage III spinal GCTs undergoing surgery at our institution who were followed for at least 2 years were retrospectively reviewed.

RESULTS

Eight men and 17 women (mean age: 34.2 years, range 16-51 years, at the time of surgery) were included. Six patients underwent previous tumor excision at another hospital, and one patient had a history of denosumab treatment. The GCTs were at the cervical, thoracic, and lumbar levels in three, nine, and 13 patients, respectively. TES was performed in 13 patients; 12 required intralesional pediculotomy. The remaining patients underwent total piecemeal spondylectomy with further intralesional tumor resection. During a mean follow-up of 99.2 months (range 24-216), two patients who underwent total piecemeal spondylectomy had local tumor recurrence, but no patients who underwent TES with intralesional pediculotomy had recurrence. The 2- and 10-year recurrence-free survival rates of patients treated with total piecemeal spondylectomy were 91.7% and 78.6%, respectively, while those of patients treated with TES were both 100%.

CONCLUSIONS

TES with intralesional pediculotomy had a good surgical outcome even in patients with Enneking stage III spinal GCT, suggesting that minimal intralesional procedures could radically cure spinal GCTs. These slides can be retrieved under Electronic Supplementary Material.

Recurrent giant cell tumour of the maxillary sinus and pterygoid process treated with denosumab

We report the case of a 74-year-old man with a giant cell tumour (GCT) of the right maxilla and pterygoid process. The patient presented to the maxillofacial and head and neck surgery clinic with an ulcerated lesion of the hard palate. Initial workup with CT revealed a mass within the right maxillary sinus and pterygoid process with associated bone expansion and erosion. Biopsy showed a GCT with mucosal ulceration. Two years after surgical resection, a follow-up CT revealed tumour recurrence involving the right pterygoid process and lateral pterygoid muscle. The patient was then proposed for therapy with denosumab. Under denosumab treatment, the lesion maintained stable dimensions and became sclerotic and heavily ossified.

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.

The RANK/RANKL/OPG system in tumorigenesis and metastasis of cancer stem cell: potential targets for anticancer therapy

The molecular triad involving receptor activator of nuclear factor kβ (RANK)/RANK ligand (RANKL)/osteoprotegerin cytokine system has been well implicated in several physiological and pathological processes including bone metabolism, mammary gland development, regulation of the immune function, tumorigenesis and metastasis of cancer stem cell, thermoregulation, and vascular calcification. However, this review aimed to summarize several original and up-to-date articles focusing on the role of this signaling system in cancer cell development and metastasis as well as potential therapeutic agents targeting any of the three tumor necrotic factor super family proteins and/or their downstream signaling pathways. The RANK/RANKL axis has direct effects on tumor cell development. The system is well involved in the development of several primary and secondary tumors including breast cancer, prostate cancer, bone tumors, and leukemia. The signaling of this triad system has also been linked to tumor invasiveness in the advanced stage. Bone is by far the most common site of cancer metastasis. Several therapeutic agents targeting this system have been developed. Among them, a monoclonal antibody, denosumab, was clinically approved for the treatment of osteoporosis and cancer-related diseases.

Denosumab: Current Use in the Treatment of Primary Bone Tumors

Denosumab, a human monoclonal antibody that inhibits bone resorption by binding on the receptor activator of the nuclear factor kappa-β ligand, has recently emerged as an additional option in the treatment of musculoskeletal osteolytic tumors. This article focuses on the recent literature regarding the effectiveness of denosumab in the management of giant cell tumor, multiple myeloma, aneurysmal bone cyst, and osteosarcoma. The mechanism of action of denosumab in the management of these tumors and the associated side effects are discussed in detail. [ Orthopedics. 2017; 40(4):204-210.].

Morphological Transformation of Giant-Cell Tumor of Bone After Treatment with Denosumab: A Case Report

CASE

Denosumab, an inhibitor of RANKL (receptor activator of nuclear factor κ-B ligand), was recently introduced for the treatment of giant-cell tumor of bone (GCTB). We describe the clinical, radiographic, and histological features of a GCTB of the spine in a 24-year-old woman that progressed after neoadjuvant treatment with denosumab. Disappearance of the multinuclear osteoclastic giant cells was accompanied by newly formed woven bone, which was deposited in interconnected strands with a prominent fibrovascular stroma that was histologically and radiographically similar to that of an osteoblastoma.

CONCLUSION

Pathologists, radiologists, and surgeons should be aware of this post-treatment transformation to avoid misdiagnosis.

Bortezomib Inhibits Giant Cell Tumor of Bone through Induction of Cell Apoptosis and Inhibition of Osteoclast Recruitment, Giant Cell Formation, and Bone Resorption

Giant cell tumor of bone (GCTB) is a rare and highly osteolytic bone tumor that usually leads to an extensive bone lesion. The purpose of this study was to discover novel therapeutic targets and identify potential agents for treating GCTB. After screening the serum cytokine profiles in 52 GCTB patients and 10 normal individuals using the ELISA assay, we found that NF-κB signaling-related cytokines, including TNFα, MCP-1, IL1α, and IL17A, were significantly increased in GCTB patients. The results were confirmed by IHC that the expression and activity of p65 were significantly increased in GCTB patients. Moreover, all of the NF-κB inhibitors tested suppressed GCTB cell growth, and bortezomib (Velcade), a well-known proteasome inhibitor, was the most potent inhibitor in blocking GCTB cells growth. Our results showed that bortezomib not only induced GCTB neoplastic stromal cell (NSC) apoptosis, but also suppressed GCTB NSC-induced giant cell differentiation, formation, and resorption. Moreover, bortezomib specifically suppressed GCTB NSC-induced preosteoclast recruitment. Furthermore, bortezomib ameliorated GCTB cell-induced bone destruction in vivo As a result, bortezomib suppressed NF-κB-regulated gene expression in GCTB NSC apoptosis, monocyte migration, angiogenesis, and osteoclastogenesis. Particularly, the inhibitory effects of bortezomib were much better than zoledronic acid, a drug currently used in treating GCTB, in our in vitro experimental paradigms. Together, our results demonstrated that NF-κB signaling pathway is highly activated in GCTB, and bortezomib could suppress GCTB and osteolysis in vivo and in vitro, indicating that bortezomib is a potential agent in the treatment of GCTB. Mol Cancer Ther; 15(5); 854-65. ©2016 AACR.

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.

Systemic therapy for selected skull base sarcomas: Chondrosarcoma, chordoma, giant cell tumour and solitary fibrous tumour/hemangiopericytoma

This review highlights the data currently available on the activity of systemic therapy in chondrosarcoma, chordoma, giant cell tumour of the bone (GCTB) and solitary fibrous tumour, i.e., four rare sarcomas amongst mesenchymal malignancy arising from the skull base.

Tibial stress reaction presenting as bilateral shin pain in a man taking denosumab for giant cell tumor of the bone

Prolonged bisphosphonate use has been associated with increased risk of atypical femoral fractures. Very few cases of atypical femoral fractures have been reported with denosumab. We report a case of bilateral tibial stress reactions in a 60-year-old man with no history of osteoporosis who was on prolonged high-dose denosumab for the treatment of giant cell tumor of bone. He presented with a 3-month history of pain in his bilateral shins worsening with activity and improving with rest. Although initial radiographs were unremarkable, he was found to have changes consistent with a stress reaction on magnetic resonance imaging of the distal tibia. To our knowledge, bilateral tibial stress reactions have not been previously reported with anti-resorptive therapies (neither bisphosphonates nor denosumab). Our case is intriguing in terms of the development of stress reactions as a precursor to stress fractures which may also relate to atypical fractures. Our case suggests a possible association between denosumab use and stress reactions. Of note the indication for denosumab in our case was for the treatment of giant cell tumor of bone where the Food and Drug Administration (FDA) approved dose is substantially higher than the FDA approved dose for osteoporosis treatment. Although rare, clinicians should consider the possibility of stress fractures in patients on anti-resorptive medications such as denosumab, especially when a patient presents with new onset thigh pain, hip pain or pain over an area affecting the long bones. Evaluation by imaging of affected areas should be pursued to enable early detection and intervention, as well as prevention of morbidity and associated ongoing risk to the patient.

OPG-Fc but Not Zoledronic Acid Discontinuation Reverses Osteonecrosis of the Jaws (ONJ) in Mice

Osteonecrosis of the jaws (ONJ) is a significant complication of antiresorptive medications, such as bisphosphonates and denosumab. Antiresorptive discontinuation to promote healing of ONJ lesions remains highly controversial and understudied. Here, we investigated whether antiresorptive discontinuation alters ONJ features in mice, employing the potent bisphosphonate zoledronic acid (ZA) or the receptor activator of NF-κB ligand (RANKL) inhibitor OPG-Fc, utilizing previously published ONJ animal models. Mice were treated with vehicle (veh), ZA, or OPG-Fc for 11 weeks to induce ONJ, and antiresorptives were discontinued for 6 or 10 weeks. Maxillae and mandibles were examined by μCT imaging and histologically. ONJ features in ZA and OPG-Fc groups included periosteal bone deposition, empty osteocyte lacunae, osteonecrotic areas, and bone exposure, each of which substantially resolved 10 weeks after discontinuing OPG-Fc but not ZA. Full recovery of tartrate-resistant acid phosphatase-positive (TRAP+) osteoclast numbers occurred after discontinuing OPG-Fc but not ZA. Our data provide the first experimental evidence demonstrating that discontinuation of a RANKL inhibitor, but not a bisphosphonate, reverses features of osteonecrosis in mice. It remains unclear whether antiresorptive discontinuation increases the risk of skeletal-related events in patients with bone metastases or fracture risk in osteoporosis patients, but these preclinical data may nonetheless help to inform discussions on the rationale for a "drug holiday" in managing the ONJ patient.

'Salvage Treatment' of Aggressive Giant Cell Tumor of Bones with Denosumab

Giant cell tumor of the bone (GCTB) presents as a lytic lesion of epiphyseometaphyseal regions of the long bones usually during the second to the fourth decade with female predilection. Histologically, they are formed of neoplastic mononuclear cells with a higher receptor activator of nuclear factor kappa-B ligand (RANKL) expression responsible for the aggressive osteolytic nature of the tumour. RANKL helps in the formation and functioning of osteoclasts. A newer molecule, Denosumab, is a monoclonal antibody directed against RANKL and thus prevents the formation and function of osteoclasts. Management of refractory, multicentric, recurrent, or metastatic GCTB remains challenging as achieving a tumor-free margin surgically is not always possible. Denosumab may play a crucial role, especially in the management of such difficult lesions. We present three cases of locally aggressive GCTB (involving proximal humerus, sacrum, and proximal femur) that were treated and responded very well to Denosumab therapy.

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.

IgE immunotherapy against cancer

The success of antibody therapy in cancer is consistent with the ability of these molecules to activate immune responses against tumors. Experience in clinical applications, antibody design, and advancement in technology have enabled antibodies to be engineered with enhanced efficacy against cancer cells. This allows re-evaluation of current antibody approaches dominated by antibodies of the IgG class with a new light. Antibodies of the IgE class play a central role in allergic reactions and have many properties that may be advantageous for cancer therapy. IgE-based active and passive immunotherapeutic approaches have been shown to be effective in both in vitro and in vivo models of cancer, suggesting the potential use of these approaches in humans. Further studies on the anticancer efficacy and safety profile of these IgE-based approaches are warranted in preparation for translation toward clinical application.