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

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.

Role of cancer stem cells in the development of giant cell tumor of bone

The primary bone tumor is usually observed in adolescence age group which has been shown to be part of nearly 20% of the sarcomas known today. Giant cell tumor of bone (GCTB) can be benign as well as malignant tumor which exhibits localized dynamism and is usually associated with the end point of a long bone. Giant cell tumor (GCT) involves mononuclear stromal cells which proliferate at a high rate, multinucleated giant cells and stromal cells are equally present in this type of tumor. Cancer stem cells (CSCs) have been confirmed to play a potential role in the development of GCT. Cancer stem cell-based microRNAs have been shown to contribute to a greater extent in giant cell tumor of bone. CSCs and microRNAs present in the tumors specifically are a great concern today which need in-depth knowledge as well as advanced techniques to treat the bone cancer effectively. In this review, we attempted to summarize the role played by cancer stem cells involving certain important molecules/factors such as; Mesenchymal Stem Cells (MSCs), miRNAs and signaling mechanism such as; mTOR/PI3K-AKT, towards the formation of giant cell tumor of bone, in order to get an insight regarding various effective strategies and research advancements to obtain adequate knowledge related to CSCs which may help to focus on highly effective treatment procedures for bone tumors.

Current status of bone cementing and bone grafting for giant cell tumour of bone: a systemic review

INTRODUCTION

Extended intralesional curettage, together with bone grafting/cementing, is considered as a surgical treatment option for giant cell tumour of the bone. This study aimed to discover the efficacy and recurrence rate with the use of bone cement in giant cell tumour and to compare it with that of bone grafting.

MATERIAL AND METHODS

The present systemic review is derived from the publications in the past 10 years (2009-2018). A literature search was performed via PubMed, using suitable keywords and Boolean operators database ('Giant cell tumor,' 'osteoclastoma,' 'bone,' 'bone cement,' 'bone graft' and 'curettage'). A detailed statistical analysis of the data derived from the published literature was done.

RESULTS

The patients who underwent bone graft only exhibited significantly higher recurrence rates than those treated with polymethyl methacrylate only (risk ratio 1.90; 95% confidence interval 1.14, 3.16; overall effect Z = 2.488; P-value 0.012). The observational analysis was done in rest of the seven studies; three studies showed no recurrence rate. Only one study reported the highest recurrence rate of 42% and the remaining six had an overall recurrence rate of 20.4%.

CONCLUSION

The use of bone cement was associated with a statistically significantly lower recurrence rate than bone grafting in giant cell tumour of bones. We therefore recommend the use of bone cement with extensive intralesional curettage. Adjuvant therapy like electrocautery, phenol irrigation and the use of intravenous denosumab or bisphosphonates may help in decreasing the incidence of recurrence in giant cell tumour of bone.

Denosumab in Patients with Giant Cell Tumor and Its Recurrence: A Systematic Review

Recent studies suggest that Denosumab reduces tumor size, therefore, makes the surgery easier with lower morbidity. However, some studies have reported several complications for this drug. So, this systematic review was performed to determine the effectiveness and safety of Denosumab in reducing bone destructions activity of giant cell tumor and skeletal-related events (SRE) in affected patients with giant cell tumor of bone (GCTB) and its recurrence. We explored studies in PubMed, and Cochrane Library. For this purpose, articles of various levels were retrieved until October 22, 2016. Two reviewers assessed the articles independently based on predefined criteria to extract the relevant data. Primary outcomes associated with skeletal-related event, overall survival, and secondary outcomes such as pain, quality of life and adverse events were evaluated and analyzed. The total population of this meta-analysis consisted of 686 patients. Of this population, 55% had primary GCTB and 45% had giant cell tumor recurrence, with 2% experiencing secondary recurrence. The results showed the effectiveness of Denosumab in reducing the tumor size due to inhibiting the Osteoclastogenesis. Denosumab didnot show any effect on reducing tumor recurrence, but, in cases where complete tumor surgery is not possible and tumor residuals may remain, Denosumab can be helpful. Also, the clinicians should consider the risk benefit of Denosumab.

Insights into the pathogenesis of Langerhans cell histiocytosis: the development of targeted therapies

More than a century after its first description, Langerhans cell histiocytosis (LCH) still remains an intriguing disease. Considerable progress in understanding its biology has been achieved recently. Description of the V600E BRAF mutation in samples of LCH tissue in 2010 was followed by description of additional mutations, all leading to constitutive ERK activation. Current experimental data suggest that LCH is a myeloid neoplasia with inflammatory properties, yet the exact pathophysiology remains poorly understood. Disease management paradigms have changed over time, closely reflecting the evolving view of the nature of the disease. The international Histiocyte Society have conducted three prospective clinical studies on multisystem LCH since the early 1990s. The standard frontline therapy for patients with multisystem LCH based on the cumulative knowledge of those trials consists of 6–12 weeks of initial therapy (daily oral steroids and weekly vinblastine injections), followed by pulses of prednisolone/vinblastine every 3 weeks, for a total treatment duration of 12 months. A currently ongoing study (LCH-IV) with a complex design (five interventional and two observational strata) targets further reduction of mortality and morbidity by tailoring treatment intensity depending on expected risk, as well as by exploring treatment regimens for special locations. Current knowledge on LCH pathobiology opens opportunities for improvement in the patient outcome. The activating BRAF and MAP2K1 mutations collectively accounting for about 75% of the LCH population as well as the resulting constitutive activation of downstream ERK offer an opportunity for targeted treatment. Related issues (eg, finding most effective and less toxic drugs or combinations, appropriate dosage, and optimal treatment duration) must be addressed in controlled prospective trials. Additional mechanisms, such as the interactions of the mutated dendritic cell clone with other inflammatory cells and key cytokines and chemokines, still remain attractive targets for therapeutic intervention, particularly in patients with localized, less aggressive disease.