Giant cell tumour of bone in the denosumab era

Preoperative denosumab treatment with curettage may be a risk factor for recurrence of giant cell tumor of bone

PURPOSE

Giant cell tumor of bone (GCTB) is a local aggressive bone tumor, histologically classified as intermediate malignancy. Recently, the RANKL inhibitor, denosumab, was developed as a novel and effective treatment option for GCTB. Since the risk of preoperative use of denosumab with curettage had been previously reported, this study aimed to investigate the relationship between recurrences and clinicopathological features associated with adjuvant denosumab treatment in GCTB.

METHODS

A total of 87 GCTB cases were treated at our institution. We reviewed 66 patients with conventional-type GCTB occurring in the extremities and analyzed 78 surgical treatments, including curettages and resections, with clinicopathological features and denosumab treatment.

RESULTS

GCTB lesions, including 66 primary and 12 recurring, underwent surgical treatment like curettage and resection. Recurrence-free survivals in 78 GCTB surgeries were 78.7% in 3 years and 71.9% in 5 years. In the resected cases of GCTBs, there was no recurrence either with or without denosumab. In curettage cases, 3-year recurrence-free survivals were 0.0% (n = 3) in preoperative treatment of denosumab, 66.7% (n = 6) in postoperative treatment, and 76.6% (n = 43) in no treatment. Interestingly, three preoperative treatment cases demonstrated low MIB-1 index despite 100% recurrence. The other clinicopathological factors did not contribute much to the risk of recurrence in curettage cases.

CONCLUSION

Our findings revealed the use of denosumab in GCTB, prior to curettage, to possibly increase the risk of local recurrence. Together with previous reports, our finding might provide information for beneficial treatment of GCTB.

Prognostic Factors for Survival in Patients with Malignant Giant Cell Tumor of Bone: A Risk Nomogram Analysis Based on the Population

Background

Malignant giant cell tumor of bone (MGCTB) is a rare histological type of malignant tumor that has a high tendency for local relapse and distant metastasis and ultimately leads to a poor prognosis. The purpose of this study was to describe the epidemiological features, identify the prognostic factors, and construct nomograms for patients with MGCTB.

Material/Methods

Patients with MGCTB that was histologically diagnosed between 1973 and 2014 were selected from the Surveillance, Epidemiology, and End Results (SEER) database as a training set. Survival analysis, Lasso regression, and random forests were used to identify the prognostic variables and establish the nomograms for patients with MGCTB, while an external cohort of 37 patients from our own institution and an external cohort of 163 patients from the SEER database in 2016 were used to validate the generalization performance of the nomograms.

Results

In total, univariate and multivariable analysis indicated that age, International Classification of Diseases for Oncology, historical stage, primary site, surgery information, radiotherapy, and chemotherapy were independent prognostic variables for overall survival or cause-specific survival. Nomograms based on the multivariable models were built to predict survival, and we achieved a higher C-index in subsequent multidimensional validation.

Conclusions

Age, historical stage, and chemotherapy were independent prognostic variables for overall survival and cause-specific survival of MGCTB patients, and radiotherapy and primary site were independent prognostic variables for overall survival. Nomograms based on significant clinicopathological features and clinical experience can be effective in predicting the probability of survival for MGCTB patients.

The use of denosumab in the setting of acute pathological fracture through giant cell tumour of bone

Background

Denosumab (Xgeva^TM) is a fully human antibody to RANK-Ligand, an important signal mediator in the pathogenesis of giant cell tumour of bone (GCTB). The use of denosumab in the treatment of GCTB has changed the way in which these tumours are managed over the past years.

Case presentation

Described is the case of an acute fracture through a GCTB of the distal radius of a fit and well 32-year-old, non-smoking, female patient following a simple fall onto her outstretched, dominant hand. The aim was to enable joint sparing management for the patient, as opposed to an acute fusion procedure of the carpus. The patient underwent percutaneous k-wire fixation with application of plaster and immediate commencement with denosumab to halt the activity of the GCTB. Bone healing was rapid; plaster and k-wires were removed after 6 weeks. At 6 months denosumab, was ceased and an open curettage and grafting procedure of the tumour bed was undertaken (using MIIG X3, Wright Medical, aqueous calcium sulphate as graft material).

Conclusions

The use of denosumab in the acute setting of pathological fracture through giant cell tumour of bone allowing joint salvage has not been previously described. The treatment was well tolerated and functional outcomes are excellent, with very promising 4-year follow-up.

This novel approach may allow for more joint sparing strategies in the future for other patients in this difficult situation. Further cases will need to be gathered to establish this technique as a suitable treatment pathway.

The role of Denosumab in joint preservation for patients with giant cell tumour of bone

AIMS

Local recurrence remains a challenging and common problem following curettage and joint-sparing surgery for giant cell tumour of bone (GCTB). We previously reported a 15% local recurrence rate at a median follow-up of 30 months in 20 patients with high-risk GCTB treated with neoadjuvant Denosumab. The aim of this study was to determine if this initial favourable outcome following the use of Denosumab was maintained with longer follow-up.

METHODS

Patients with GCTB of the limb considered high-risk for unsuccessful joint salvage, due to minimal periarticular and subchondral bone, large soft tissue mass, or pathological fracture, were treated with Denosumab followed by extended intralesional curettage with the goal of preserving the joint surface. Patients were followed for local recurrence, metastasis, and secondary sarcoma.

RESULTS

A total of 25 patients with a mean age of 33.8 years (18 to 67) with high-risk GCTB received median six cycles of Denosumab before surgery. Tumours occurred most commonly around the knee (17/25, 68%). The median follow-up was 57 months (interquartile range (IQR) 13 to 88). The joint was salvaged in 23 patients (92%). Two required knee arthroplasty due to intra-articular fracture and arthritis. Local recurrence developed in 11 patients (44%) at a mean of 32.5 months (3 to 75) following surgery, of whom four underwent repeat curettage and joint salvage. One patient developed secondary osteosarcoma and another benign GCT lung metastases.

CONCLUSION

The use of Denosumab for joint salvage was associated with a higher than expected rate of local recurrence at 44%. Neoadjuvant Denosumab for joint-sparing procedures should be considered with caution in light of these results. Cite this article: Bone Joint J 2021;103-B(1):184-191.

Dosing interval adjustment of denosumab for the treatment of giant cell tumor of the sphenoid bone: A case report

Background:

In the treatment of giant cell tumor of bone (GCTB), the efficacy and safety of denosumab, a receptor activator nuclear factor κ-B ligand inhibitor, has previously been demonstrated, especially for unresectable tumors. One of the current issues in denosumab treatment for unresectable GCTB is whether it can be discontinued, or whether the dosage or the dosing interval can safely be adjusted, if discontinuation is not possible, to avoid the occurrence of side effects.

Case Description:

A 15-year-old boy with diplopia was referred to our hospital after a space-occupying lesion in the sphenoid bone was found on head CT. Partial removal of the tumor was performed through an endoscopic endonasal approach, and pathological diagnosis was confirmed as GCTB. Thereafter, the patient received 120 mg subcutaneous injections of denosumab every 28 days for the first 2 years. Since bone formation was induced and sustained along with tumor reduction, the dosing interval was gradually extended, with 4 monthly dosing for the next 1 year, followed by 6 monthly dosing for the succeeding 2 years. With the extension of the dosing interval, the ossified tumor has regrown slightly, but within an acceptable range.

Conclusion:

Discontinuation of denosumab treatment for unresectable GCTB was not thought to be possible for the current case due to the nature of the drug, as reported in the literature. Extending the dosing interval up to 6 monthly, as could be done safely in the current case, can be considered a useful and appropriate measure.

Integration of denosumab therapy in the management of giant cell tumors of bone

A review of the literature indicated denosumab is gaining favorability in the oncology community, particularly with increasing frequency in GCTB. Will denosumab be the breakthrough GCTB treatment? Here, we provide a pertinent case example, a review of the literature regarding the history and basic science behind the use of denosumab for GCTB, highlight the newest insights into the dosing and duration of treatment, and note advancements in the field.

Genomic Medicine: Lessons Learned From Monogenic and Complex Bone Disorders

Current genetic studies of monogenic and complex bone diseases have broadened our understanding of disease pathophysiology, highlighting the need for medical interventions and treatments tailored to the characteristics of patients. As genomic research progresses, novel insights into the molecular mechanisms are starting to provide support to clinical decision-making; now offering ample opportunities for disease screening, diagnosis, prognosis and treatment. Drug targets holding mechanisms with genetic support are more likely to be successful. Therefore, implementing genetic information to the drug development process and a molecular redefinition of skeletal disease can help overcoming current shortcomings in pharmaceutical research, including failed attempts and appalling costs. This review summarizes the achievements of genetic studies in the bone field and their application to clinical care, illustrating the imminent advent of the genomic medicine era.

Denosumab in Giant Cell Tumor of Bone: Current Status and Pitfalls

Denosumab is a monoclonal antibody against RANK ligand for treatment of giant cell tumor of bone (GCTB). Clinical trials and case series have demonstrated that denosumab is relevant to beneficial tumor response and surgical down-staging in patients of GCTB. However, these trials or case series have limitations with a short follow-up. Recent increasing studies revealed that denosumab probably increased the local recurrence risk in patients treated with curettage. This may be caused by the thicken bone margin of tumor that trapped tumor cells from curettage. The direct bone formation by tumor cells in the margin after denosumab treatment also contributed to the local recurrence. in vitro studies showed denosumab resulted in a cytostatic instead of a true cytotoxic response on neoplastic stromal cells. More importantly, denosumab-treated GCTB exhibited morphologic overlap with malignancy, and a growing number of patients of malignant transformation of GCTB during denosumab treatment have been reported. The optimal duration, long term safety, maintenance dose, and optimum indications remain to be elucidated. With these concerns in mind, this review warns that the denosumab therapy of GCTB should be applied with caution.

Secondary Osteoarthritis After Curettage and Calcium Phosphate Cementing for Giant-Cell Tumor of Bone Around the Knee Joint: Long-Term Follow-up

Giant-cell tumor of bone (GCTB) is a locally aggressive intermediate bone tumor with a rarely metastasizing disposition. Standard surgical treatment consists of curettage, adjuvant treatment, and augmentation with allograft, autograft, or synthetics. Polymethylmethacrylate (PMMA) has been widely used for augmentation of the bone defect; however, the hyperthermic polymerization of PMMA may cause damage to articular cartilage, and the stiffness of the material may decrease the ability of the joint to absorb shock. These properties were reported to result in secondary osteoarthritis. Calcium phosphate cement has a low degree of thermal reaction and a strength that is similar to cortical bone. The aim of the present study was to investigate the incidence of secondary osteoarthritis around the knee joint following augmentation with calcium phosphate cement.

Significance of EGFR/HER2 Expression and PIK3CA Mutations in Giant Cell Tumour of Bone Development

Giant Cell Tumour of Bone (GCTB) is a rare bone tumour. Locally aggressive and recurrent, it might evolve into pulmonary metastases. Our present work is aimed at investigating the involvement of the epidermal growth factor receptor (ErbB) family and its downstream effectors in the development and recurrence of GCTB. For this purpose, we used a cohort of 32 GCTB patients and we evaluated the clinicohistological features and the expression of RANKL, EGFR, and HER2. The mutation status of KRAS, PI3KCA, and PTEN gene as potential oncogene involved in GCTB was also evaluated. We found a significant correlation between advanced histological stages, overexpression of EGFR/HER2, and tumour recurrence. Moreover, two mutations were found in the PIK3CA gene: a missense mutation, 1634A>C, detected for the first time in GCTB patients, without influencing the stability of the protein, and a frameshift mutation, c.1658_1659delGTinsC, causing the loss of the protein kinase domain. Altogether, these results suggest that overexpression of HER2/EGFR, Campanacci, and histological stages could be used as a novel prognostic marker for GCTB recurrence.

Paraspinal pseudoneoplasms: a series of 58 consultation cases emphasizing the importance of pathology-radiology correlation

A variety of non-neoplastic diseases of the spine, including herniated/sequestered intervertebral discs, synovial cysts, and degenerative or post-traumatic changes, may present as mass lesions. Over the past several years, we have seen a large number of such paraspinal pseudoneoplasms in consultation, referred out of concern for malignancy on the part of the clinician, pathologist, or both. Herein, we report our experience with these specimens, emphasizing the clinical, radiologic, and histopathological features that allow their confident distinction from various mesenchymal tumors. Fifty-eight cases were identified within our consultation archives, referred in consultation to exclude malignancy and diagnosed as non-neoplastic disease involving the intervertebral disc, ligamentum flavum, or paraspinal soft tissues (2006-2019). Available radiologic studies were reviewed by 2 musculoskeletal radiologists. The histologic features of all cases were re-evaluated. Available clinical records were reviewed. The masses occurred in adults (median age 62 years, range 20-86 years) with a male predominance (35 males and 23 females). Sites included lumbar spine (N = 33), thoracic spine (N = 15), cervical spine (N = 6), paraspinal region (N = 3), and sacral spine (N = 1). In 44 cases (76%), the referring pathologist regarded the specimen as representing a benign or malignant neoplasm, either primary or metastatic. Fifteen cases (26%) were sent for second opinion at the request of the treating clinician, following an initial malignant diagnosis. Advanced imaging studies were available for re-review in 37 cases (64%) and showed herniated/extruded disc (N = 17), compression fracture (N = 9), synovial cyst (N = 8), and degenerative joint disease (N = 7). Multiple radiologic findings were seen in 9 patients. Histologically, the specimens showed a spectrum of often florid reactive changes involving degenerating disc material, ligamentum flavum, and bone. Awareness that non-neoplastic spinal processes may form pseudoneoplastic mass lesions, and careful clinical-radiologic-pathologic correlation should allow their confident distinction from potential morphologic mimics.

THE USE OF DENOSUMAB IN GIANT CELL TUMORS IN THE SACRUM

ABSTRACT Giant Cell Tumor (GCT), a benign tumor with local aggression, corresponds to 5% of primary tumors. Fifteen percent of these are located in the sacrum. En bloc resection is an effective treatment, but when it cannot be performed, Denosumab may be indicated as an alternative treatment. The objectives of this work are: to justify the indication; determine the best dose and time of use; and recognize the need for post-treatment surgery. Methods A systematic search of clinical trials. Twenty-five articles were selected, ten of which met the inclusion criteria. The use of Denosumab is justified in advanced stages, with a dose of 120 mg administered subcutaneously, every 7 days in the first month and then maintained every 4 weeks, for 2.5 to 13 months. Adverse events are mild and can be observed in 84% of patients. With Denosumab, surgery may be less aggressive or even unnecessary. The bibliography justifies the indication of Denosumab in advanced stages of GCT, with a dose of 120 mg administered subcutaneously; there is no consensus as to the maintenance dose, which is a weekly dose in the first month and then every four weeks for 2.5 to 13 months. Complications are frequent but mild. Level of evidence III; Systematic review.

Prognostic role of PD-L1 and immune-related gene expression profiles in giant cell tumors of bone

Giant cell tumor of bone (GCTB) is a locally aggressive and rarely metastatic tumor, with a relatively unpredictable clinical course. A retrospective series of 46 GCTB and a control group of 24 aneurysmal bone cysts (ABC) were selected with the aim of investigating the PD-L1 expression levels and immune-related gene expression profile, in correlation with clinicopathological features. PD-L1 and Ki67 were immunohistochemically tested in each case. Furthermore, comprehensive molecular analyses were carried out using NanoString technology and nCounter PanCancer Immune Profiling Panel, and the gene expression results were correlated with clinicopathological characteristics. PD-L1 expression was observed in 13/46 (28.3%) GCTB (and in 1/24, 4.2%, control ABC, only) and associated with a shorter disease free interval according to univariate analysis. Moreover, in PD-L1-positive lesions, three genes (CD27, CD6 and IL10) were significantly upregulated (p < 0.01), while two were downregulated (LCK and TLR8, showing borderline significance, p = 0.06). Interestingly, these genes can be related to maturation and immune tolerance of bone tissue microenvironment, suggesting a more immature/anergic phenotype of giant cell tumors. Our findings suggest that PD-L1 immunoreactivity may help to select GCTB patients with a higher risk of recurrence who could potentially benefit from immune checkpoint blockade.

Benign albeit glycolytic: MCT4 expression and lactate release in giant cell tumour of bone

Giant cell tumour of bone (GCTB) is a histologically benign, locally aggressive skeletal lesion with an unpredictable propensity to relapse after surgery and a rare metastatic potential. The microscopic picture of GCTB shows different cell types, including multinucleated giant cells, mononuclear cells of the macrophage-monocyte lineage, and spindle cells. The histogenesis of GCTB is still debated, and morphologic, radiographic or molecular features are not predictive of the clinical course. Characterization of the unexplored cell metabolism of GCTB offers significant clues for the understanding of this elusive pathologic entity. In this study we aimed to characterize GCTB energetic metabolism, with a particular focus on lactate release and the expression of monocarboxylate transporters, to lie down a novel path for understanding the pathophysiology of this tumour. We measured the expression of glycolytic markers (GAPDH, PKM2, MCT4, GLUT1, HK1, LDHA, lactate release) in 25 tissue samples of GCTB by immunostaining and by mRNA and ELISA analyses. We also evaluated MCT1 and MCT4 expression and oxidative markers (JC1 staining and Bec index) in tumour-derived spindle cell cultures and CD14+ monocytic cells. Finally, we quantified the intratumoural and circulating levels of lactate in a series of 17 subjects with GCTB. In sharp contrast to the benign histological features of GCTB, we found a high expression of glycolytic markers, with particular reference to MCT4. Unexpectedly, this was mainly confined to the giant cell, not proliferating cell component. Accordingly, GCTB patients showed higher levels of blood lactate as compared to healthy subjects. In conclusion, taken together, our data indicate that GCTB is characterized by a highly glycolytic metabolism of its giant cell component, opening new perspectives on the pathogenesis, the natural history, and the treatment of this lesion.

Is Treatment with Denosumab Associated with Local Recurrence in Patients with Giant Cell Tumor of Bone Treated with Curettage? A Systematic Review

BACKGROUND

Denosumab, a monoclonal antibody that binds to receptor activation of nuclear factor-kappa ß ligand (RANKL), has been used as a drug to treat aggressive giant cell tumors of bone. It is unclear whether preoperative denosumab therapy is associated with the local recurrence risk in patients with giant cell tumors of bone treated with curettage. Early evidence suggests that denosumab treatment is associated with a reduction in local recurrence, but other studies have questioned that premise. Curettage after a short course of denosumab (3 to 4 months) has been recommended, especially for large, aggressive giant cell tumors in which complete curettage is difficult to achieve. No randomized studies have documented the benefit of this approach, and some investigators have reported higher local recurrence after denosumab treatment. Due to this confusion, we performed a systematic analysis of existing reports to attempt to answer this question and determine whether the appropriate preoperative denosumab therapy duration could be established.

QUESTIONS/PURPOSES

(1) Is the use of preoperative denosumab associated with local recurrence risk in patients with giant cell tumors of bone treated with curettage compared with those treated with curettage alone? (2) Is the preoperative denosumab therapy duration associated with local recurrence after curettage?

METHODS

We searched the PubMed, EMBASE, and CENTRAL databases on April 26, 2019 and included both randomized and non-randomized studies that compared local recurrence between patients who had giant cell tumors of bone and were treated with curettage after preoperative denosumab and patients treated with curettage alone. Two authors independently screened the studies. There were no randomized studies dealing with denosumab in giant cell tumors of bone, and generally, denosumab was used for more aggressive tumors. We assessed the quality of the included studies using the Risk of Bias Assessment tool for Non-randomized Studies, with a moderate overall risk of bias. We registered our protocol in PROSPERO (registration number CRD42019133288). We selected seven eligible studies involving 619 patients for the final analysis.

RESULTS

The proportion of patients with local recurrence ranged from 20% to 100% in the curettage with preoperative denosumab group and ranged from 0% to 50% in the curettage-alone group. The odds ratio of local recurrence ranged from 1.07 to 37.80 in no more than 6 months of preoperative denosumab duration group and ranged from 0.60 to 28.33 in more than 6 months of preoperative denosumab duration group.

CONCLUSIONS

The available evidence for the benefit of denosumab in more aggressive giant cell tumors is inconclusive, and denosumab treatment may even be associated with an increase in the proportion of patients experiencing local recurrence. Because there are no randomized studies and the existing studies are of poor quality due to indication bias (the most aggressive Campanacci 3 lesions or those where even a resection would be difficult and result in morbidity are generally the patients who are treated with denosumab), the evidence to suggest a disadvantage is weak. Denosumab treatment should be viewed with caution until more definitive, randomized studies documenting a benefit (or not) have been conducted. Furthermore, we could not find evidence to suggest an appropriate length of preoperative denosumab before curettage.

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.

[Giant cell tumor of bone : Morphology, molecular pathogenesis, and differential diagnosis]

The histological picture of giant cell tumor of bone is characterized by numerous osteoclast-like giant cells. However, these are not the actual tumor cells, but constitute a reactive infiltrate. Rather, the tumor cells are mononuclear mesenchymal cells, which even reveal an osteoblastic line of differentiation. The CD68-positive macrophages form the second group of mononuclear cells. The receptor activator of nuclear factor kappa-B/ligand (RANK/RANKL) system, which belongs to the tumor necrosis factor (TNF) cytokine family, is decisively involved in the activation of the giant cells. It is generally accepted that a RANKL expression of mononuclear stromal cells is responsible for the development and differentiation of osteoclast-like giant cells. Therefore, the RANKL inhibitor denosumab constituted an essential element for giant cell tumor therapy over the last several years, as it blocks the maturation of osteoclasts and thus the osteolytic activity and the spread of tumor. However, with time it became evident that the not risk-free therapy with denosumab may lead to extensive recurrences upon withdrawal, so this therapy is applied with caution today.At the molecular genetic level, the giant cell tumors of bone are characterized by point mutations in the H3F3A gene. The detection of this mutation is used for the diagnostic differentiation from other bone lesions containing giant cells. Giant cell osteosarcomas rarely contain H3F3A mutations. Chondroblastoma is characterized by mutations in the H3F3B gene.

Challenges of denosumab in giant cell tumor of bone, and other giant cell-rich tumors of bone

Purpose of review

Giant cell tumor of bone (GCTB) is an uncommon benign primary bone tumor, consisting of receptor activator of nuclear factor kappa-B (RANK) expressing reactive osteoclast-like giant cells and neoplastic spindle-shaped cells. Denosumab was approved by FDA in 2013 and by EMA in 2014 to treat adults and skeletally mature adolescents with unresectable GCTB or when resection is likely to result in severe morbidity. However, there is much discussion regarding the optimal applied treatment strategy.

Recent findings

Neoadjuvant treatment of GCTB with denosumab can effectively downstage tumors to facilitate less morbid surgery or completely avoid the need for resection, but there is concern about local recurrence postsurgery. Definitive treatment of unresectable GTCB improves symptoms and halts tumor progression. The optimal treatment duration is unclear and long-term treatment is associated with adverse events like osteonecrosis of the jaw (ONJ) and atypical femoral fractures. Denosumab maintenance dose interval is currently being investigated.

Summary

For the related but heterogenous group of giant cell rich tumors of bone, like aneurysmal bone cysts (ABC) and central giant cell granuloma (CGCG), denosumab is a new treatment modality under investigation. Given the effectiveness in GCTB, this could be a promising treatment option for selected patients with advanced disease.

Reconstruction with β-tricalcium phosphate for giant cell tumor of the talus

Giant cell tumor of bone (GCTB) is a locally aggressive tumor, commonly occurs in the long bones, and is rare in the talus and the foot. The talus is a weight-bearing bone and strut reconstruction is preferred. Reconstruction with low porosity β-tricalcium phosphate (β-TCP) blocks is reported for GCTB in the knee. In the current report, a 25-year-old female suffered from GCTB in the talus extending to the subchondral bone. The tumor was treated by curettage and the bone was reconstructed with low porosity β-TCP blocks, which have strong compressive strength. The implanted β-TCP blocks were incorporated successfully. The current reconstruction method can be applied for GCTB in the talus.

Retrospective cohort study of 68 sacral giant cell tumours treated with nerve-sparing surgery and evaluation on therapeutic benefits of denosumab therapy

AIMS

To investigate the benefits of denosumab in combination with nerve-sparing surgery for treatment of sacral giant cell tumours (GCTs).

METHODS

This is a retrospective cohort study of patients with GCT who presented between January 2011 and July 2017. Intralesional curettage was performed and patients treated from 2015 to 2017 also received denosumab therapy. The patients were divided into three groups: Cohort 1: control group (n = 36); cohort 2: adjuvant denosumab group (n = 9); and cohort 3: neo- and adjuvant-denosumab group (n = 17).

RESULTS

There were 68 patients within the study period. Six patients were lost to follow-up. The mean follow-up was 47.7 months (SD 23.2). Preoperative denosumab was found to reduce intraoperative haemorrhage and was associated with shorter operating time for tumour volume > 200 cm³. A total of 17 patients (27.4%) developed local recurrence. The locoregional control rate was 77.8% (7/9) and 87.5% (14/16) respectively for cohorts 2 and 3, in comparison to 66.7% (24/36) of the control group. The recurrence-free survival (RFS) rate was significantly higher for adjuvant denosumab group versus those without adjuvant denosumab during the first two years: 100% vs 83.8% at one year and 95.0% vs 70.3% at two years. No significant difference was found for the three-year RFS rate.

CONCLUSION

Preoperative denosumab therapy was found to reduce intraoperative haemorrhage and was associated with shorter operating times. Adjuvant denosumab was useful to prevent early recurrence during the first two years after surgery. Cite this article: Bone Joint J 2020;102-B(2):177-185.

Implanted β-Tricalcium Phosphate Blocks Can Function as a Placeholder in Recurrent Giant Cell Tumor of Bone

The giant cell tumor of bone (GCTB) is a locally aggressive tumor. Reconstruction methods using β-tricalcium phosphate (β-TCP) blocks with strong compression resistance in and around the knee joint for GCTB have been reported. Among six cases of GCTB treated using this method, two recurrent cases revealed osteolysis, predominantly within the β-TCP block based on plain radiographs or computed tomography, while remodeled host bones were preserved. Implanted β-TCP blocks can function as a placeholder to preserve host bone in recurrent cases, leading to a higher probability of joint preservation.

BROWN TUMORS SECONDARY TO PARATHYROID CARCINOMA MASQUERADING AS SKELETAL METASTASES ON 18F-FDG PET/CT: A CASE REPORT

Objective

Brown tumors develop as skeletal manifestations of hyperparathyroidism. Increased osteoclast activity leads to accumulation of highly active giant cells and to excess cortical bone resorption, producing fibrous cysts. Though most often reported in patients with parathyroid adenomas, brown tumors secondary to parathyroid carcinoma create a clinical dilemma. Increased signal uptake on 2-deoxy-2-(fluorine-18)fluoro-D-glucose positron emission tomography (¹⁸F-FDG PET)/computed tomography (CT) seen within brown tumors may be indistinguishable from bone metastases. We report a case of parathyroid carcinoma in a 38-year-old man presenting with osteolytic bone lesions on ¹⁸F-FDG PET/CT that were diagnosed as brown tumors by biopsy.

Methods

We describe the patient history, presentation, diagnostic studies, and treatment.

Results

We report a case of a 38-year-old man diagnosed with parathyroid carcinoma with associated hypercalcemia and elevated parathyroid hormone levels who had undergone 3 surgical resections for local recurrences and had persistent hypercalcemia. He was found to have multiple osteolytic lesions throughout his skeleton on ¹⁸F-FDG PET/CT imaging 2 months after diagnosis. Biopsy of a right scapula lesion confirmed a brown tumor.

Conclusion

The role of ¹⁸F-FDG PET/CT in management of parathyroid carcinoma has not been systematically evaluated. Skeletal manifestations of parathyroid carcinoma may be present in this imaging modality. Clinicians should consider the possibility of brown tumors in patients with parathyroid carcinoma who undergo ¹⁸F-FDG PET/CT imaging.

Radiological findings of denosumab treatment for giant cell tumours of bone

Giant cell tumours of bone (GCTB) are benign giant cell-rich tumours typically occurring in the epi-metaphysis of skeletally mature patients. Despite their benign classification, GCTB may be locally aggressive with local recurrence as a challenging issue. Denosumab is a human monoclonal antibody that inhibits osteolysis via the RANK-RANK ligand pathway. There is currently no consensus on optimal treatment duration or imaging modality for monitoring patients on denosumab therapy. This review illustrates the radiological findings of GCTB on denosumab treatment seen on plain radiographs, CT, MRI, PET-CT and DEXA, with reference to the current literature. Recognizing imaging features indicative of a positive response to denosumab is important for therapeutic decision-making. Imaging findings with respect to duration of denosumab treatment, tumour upregulation during treatment, tumour recurrence and malignant transformation are discussed. The development of a sclerotic neocortex and varying degrees of matrix osteosclerosis are seen on plain radiographs. Reconstitution of subarticular bone and articular surface irregularity are optimally evaluated on CT which can also quantify tumour density. MRI demonstrates heterogeneous low signal matrix and is useful to assess decrease in size of cystic and/or soft tissue components of GCTB. A fat-suppressed fluid-sensitive MR sequence is important to detect tumour reactivation. Reduction in ¹⁸F-FDG-PET avidity represents an early sensitive sign of response to denosumab treatment. Regardless of imaging modality, close follow-up in a specialist centre and careful evaluation of nonresponders is necessary as local recurrence after cessation of denosumab treatment and malignant transformation of GCTB have been described.

In situ cell cycle analysis in giant cell tumor of bone reveals patients with elevated risk of reduced progression-free survival

OBJECTIVE

Giant cell tumor of bone (GCTB) is a frequently recurring locally aggressive osteolytic lesion, where pathological osteoclastogenesis and bone destruction are driven by neoplastic stromal cells. Here, we studied if cell cycle fractions within the mononuclear cell compartment of GCTB can predict its progression-free survival (PFS).

METHODS

154 cases (100 primaries and 54 recurrent) from 139 patients of 40 progression events, was studied using tissue microarrays. Ploidy and in situ cell cycle progression related proteins including Ki67 and those linked with replication licensing (mcm2), G1-phase (cyclin D1, Cdk4), and S-G2-M-phase (cyclin A; Cdk2) fractions; cell cycle control (p21^waf1) and repression (geminin), were tested. The Prentice-Williams-Peterson (PWP) gap-time models with the Akaike information criterion (AIC) were used for PFS analysis.

RESULTS

Cluster analysis showed good correlation between functionally related marker positive cell fractions indicating no major cell cycle arrested cell populations in GCTB. Increasing hazard of progression was statistically associated with the elevated post-G1/S-phase cell fractions. Univariate analysis revealed significant negative association of poly-/aneuploidy (p < 0.0001), and elevated cyclin A (p < 0.001), geminin (p = 0.015), mcm2 (p = 0.016), cyclin D1 (p = 0.022) and Ki67 (B56: p = 0.0543; and Mib1: p = 0.0564 -strong trend) positive cell fractions with PFS. The highest-ranked multivariate interaction model (AIC = 269.5) also included ploidy (HR 5.68, 95%CI: 2.62-12.31, p < 0.0001), mcm2 (p = 0.609), cyclin D1 (HR 1.89, 95%CI: 0.88-4.09, p = 0.105) and cyclin A (p < 0.0001). The first and second best prognostic models without interaction (AIC = 271.6) and the sensitivity analysis (AIC = 265.7) further confirmed the prognostic relevance of combining these markers.

CONCLUSION

Ploidy and elevated replication licensing (mcm2), G1-phase (cyclin D1) and post-G1 phase (cyclin A) marker positive cell fractions, indicating enhanced cell cycle progression, can assist in identifying GCTB patients with increased risk for a reduced PFS.

Evaluation of Local Recurrence in Giant-Cell Tumor of Bone Treated by Neoadjuvant Denosumab

Background

Giant-cell tumor of bone (GCTB) is a locally aggressive primary benign tumor presenting as an expansile osteolytic lesion affecting the epiphysis of long bones. Denosumab halts the osteolysis by giant cells thereby downstaging the tumor, helping in performing less morbid procedures to remove the tumor. Our aim was to report the incidence of local recurrence (LR) in patients operated following neoadjuvant denosumab, to investigate factors associated with LR following extended curettage for GCTB, and to compare the postoperative functional and oncological outcome of patients operated with and without neoadjuvant denosumab.

Methods

A total of 123 patients with a mean age of 29.6 years undergoing extended curettage for GCTB were retrospectively divided into group 1 receiving neoadjuvant denosumab and group 2 operated without denosumab. The mean follow-up period was 35 months. The perioperative characteristics and outcome were compared between the two groups and the factors for LR of GCTB were analyzed.

Results

The incidence of LR among patients operated after neoadjuvant denosumab therapy was 42.8% and was significantly high compared to that in patients without denosumab (p < 0.001). On multivariate logistic regression analysis, use of denosumab as a neoadjuvant was the only factor independently associated with LR following surgery (p = 0.002). Patients treated with denosumab had a lower LR-free survival rate (log-rank, p = 0.018).

Conclusions

Denosumab was independently associated with increased LR following surgery for GCTB. Denosumab has to be used cautiously in patients in whom the burden of downstaging the disease outweighs the possible chance of LR.

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

BACKGROUND

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

CASE PRESENTATION

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

CONCLUSION

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

How to optimize the therapeutic effect of free autogenous fibula graft and wrist arthroplasty for giant cell tumors of distal radius?

Objective

The purpose of this study is to retrospectively analyze the clinical efficacy of free fibula autograft and wrist arthroplasty in the treatment of giant cell tumors (GCT) of distal radius.

Methods

We retrospectively reviewed 26 patients with GCT of distal radius who underwent free autogenous fibula graft and wrist arthroplasty for repairing residual defect after en-block resection. The length of the fibula graft was 8.2 cm (6–10 cm). Postoperative follow-up regularly for an mean of 66.9 months. Bone healing was assessed by radiographs, pain was assessed by Visual Analog Scale (VAS) score and limb function was evaluated by Musculoskeletal Tumor Society (MSTS) score and disabilites of the arm, shoulder and hand (DASH) score. The range of motion (ROM) of wrist and grip strength were also evaluated.

Result

There were four males and 22 females with an mean age of 36.7 years (19–60 years); the mean length of lesions was 4.8 cm (2.3–6.6 cm); 21 primary cases and five recurrent cases; eight cases of Campanacci Grade II, 18 cases of Grade III. We had no postoperative lung metastasis and only one case had a local recurrence, three cases (11%) with subluxation of lower ulnoradial joints and five cases (19%) showed narrowing of wrist joint space. The mean postoperative VAS pain score was 0.7 ± 0.7 and grip strength retained 71% of the normal hand, MSTS score was 27.7 ± 1.1 and DASH score was 9.0 ± 3.7. The ROM of the involved wrist only slightly restricted and no donor complications. Postoperative wrist joint function was significantly improved.

Conclusion

Strict surgical resection boundary and solid reconstruction of wrist joint capsule are the key to achieving excellent oncological prognosis and function of distal radius GCT.

Neoadjuvant denosumab: its role and results in operable cases of giant cell tumour of bone

AIMS

The aims of this study were to evaluate the efficacy of preoperative denosumab in achieving prospectively decided intention of therapy in operable giant cell tumour of bone (GCTB) patients, and to document local recurrence-free survival (LRFS).

PATIENTS AND METHODS

A total of 44 patients received preoperative denosumab: 22 to facilitate curettage, 16 to facilitate resection, and six with intent of converting resection to curettage. There were 26 male and 18 female patients. The mean age was 27 years (13 to 47).

RESULTS

The mean number of denosumab treatments was five (2 to 7) per patient. In 42 of 44 patients (95%), denosumab helped to achieve prospectively decided intention. A total of 41 patients were available for follow-up at a mean follow-up of 34 months (24 to 48). There were 12 local recurrences (29%), in 11 patients (11/25, 44%) who had curettage and in one patient (1/16, 6%) who had resection. The mean time to local recurrence was 16 months (8 to 25). The LRFS was 76% at two years: 94% for cases with resection and 64% for cases with curettage (p = 0.013).

CONCLUSION

Although local control rates are unlikely to improve with use of preoperative denosumab, a short preoperative course of denosumab can facilitate surgery in certain cases of operable GCTB, with a high risk of local recurrence making curettage or resection technically easier. It may also help in converting a lesion requiring resection to a lesion that could possibly be treated with curettage.

New challenges in integrated diagnosis by imaging and osteo-immunology in bone lesions

INTRODUCTION

High-resolution imaging is the gold standard to measure the functional and biological features of bone lesions. Imaging markers have allowed the characterization both of tumour heterogeneity and metabolic data. Besides, ongoing studies are evaluating a combined use of 'imaging markers', such as SUVs, MATV, TLG, ADC from PET and MRI techniques respectively, and several 'biomarkers' spanning from chemokine immune-modulators, such as PD-1, RANK/RANKL, CXCR4/CXCL12 to transcription factors, such as TP53, RB1, MDM2, RUNX family, EZH2, YY1, MAD2. Osteoimmunology may improve diagnosis and prognosis leading to precision medicine in bone lesion treatment. Areas covered: We investigated modalities (molecular and imaging approach) useful to identify bone lesions deriving both from primary bone tumours and from osteotropic tumours, which have a higher incidence, prevalence and prognosis. Here, we summarized the recent advances in imaging techniques and osteoimmunology biomarkers which could play a pivotal role in personalized treatment. Expert commentary: Although imaging and molecular integration could allow both early diagnosis and stratification of cancer prognosis, large scale clinical trials will be necessary to translate pilot studies in the current clinical setting.

ABBREVIATIONS

ADC: apparent diffusion coefficient; ALCAM: Activated Leukocyte Cell Adhesion Molecule; ALP: Alkaline phosphatases; BC: Breast cancer; BSAP: B-Cell Lineage Specific Activator; BSAP: bone-specific alkaline phosphatase; BSP: bone sialoprotein; CRIP1: cysteine-rich intestinal protein 1; CD44: cluster of differentiation 44; CT: computed tomography; CXCL12: C-X-C motif ligand 12; CXCR4: C-X-C C-X-C chemokine receptor type 4; CTLA-4: Cytotoxic T-lymphocyte antigen 4; CTX-1: C-terminal end of the telopeptide of type I collagen; DC: dendritic cell; DWI: Diffusion-weighted MR image; EMT: mesenchymal transition; ET-1: endothelin-1; FDA: Food and Drug Administration; FDG: ¹⁸F-2-fluoro-2-deoxy-D-glucose; FGF: fibroblast growth factor; FOXC2: forkhead box protein C2: HK-2: hexokinase-2; ICTP: carboxyterminal cross-linked telopeptide of type I collagen; IGF-1R: Insulin Like Growth Factor 1 Receptor; ILC: innate lymphocytes cells; LC: lung cancer; IL-1: interleukin-1; LYVE1: lymphatic vessel endothelial hyaluronic acid receptor 1; MAD2: mitotic arrest deficient 2; MATV: metabolically active tumour volume; M-CSF: macrophage colony stimulating factor; MM: multiple myeloma; MIP1a: macrophage inflammatory protein 1a; MSC: mesenchymal stem cell; MRI: magnetic resonance imaging; PC: prostate cancer; NRP2: neuropilin 2; OPG: osteoprotogerin; PDGF: platelet-derived growth factor; PD-1: Programmed Cell Death 1; PET: positron emission tomography; PINP: procollagen type I N propeptide; PROX1: prospero homeobox protein 1; PSA: Prostate-specific antigen; PTH: parathyroid hormone; RANK: Receptor activator of NF-kB ligand; RECK: Reversion-inducing-cysteine-rich protein; SEMAs: semaphorins; SPECT: single photon computed tomography; SUV: standard uptake value; TLG: total lesion glycolysis; TP53: tumour protein 53; VCAM-1: vascular endothelial molecule-1; VOI: volume of interest; YY1: Yin Yang 1.

Managements of giant cell tumor within the distal radius: A retrospective study of 58 cases from a single center

Background

Giant cell tumor of bone (GCTB) in distal radius is a benign but invasive bone tumor characterized by strong aggressive behavior and frequent recurrence.

Methods

To identify recurrence related risk factors and decide suitable surgical strategy, the potential tumor- and treatment-specific factors, post-operative oncologic and functional outcomes were collected and analyzed from 58 patients with GCTB of the distal radius at our center.

Results

With the numbers available, our analysis strongly indicated soft tissue extension (with vs. without, HR: 5.645, 95% CI: 1.424 to 22.377, p = 0.014) and size of GCTB (diameter ≥ 5 cm vs. 5 cm HR: 3.893, 95% CI: 1.109 to 13.659, p = 0.034) are the two independent risk factors related to local relapse. Neither surgical procedures (curettage vs. en-bloc resection) nor other factors apparently affected the recurrence, including age, tumor nature, dominant hand involvement, pathological fracture conditions or pre-operative denosumab. However, intralesional curettage group achieved much better functional scores ((VAS: 2.5 ± 0.8 vs. 3.6 ± 1.2, p = 0.011; MSTS: 20.2 ± 3.4 vs. 16.7 ± 3.8, P = 0.034; DASH 9.1 ± 3.9 vs. 16.4 ± 5.5, p = 0.030) and much less complications (non-unions, dislocations, fractures and infections) compared to resection ones. Furthermore, denosumab provided dramatic pain reduction and strong tumor suppression, facilitating curettage with local adjuvants even in GCTB with advanced status.

Conclusions

Taken together, the radiographic presentations (soft-tissue extension and tumor size) are the strong prognostic predictors of local recurrence of GCTB in distal radius. In most tumors, an initial treatment with curettage remains feasible and first-choice, especially with the adjuvant denosumab.

Primary thoracic giant cell tumor of bone sensitive to steroids

Spinal giant cell tumor of bone (GCTB) is a rare benign, but locally aggressive, entity. We report the case of a 40-year-old man diagnosed with GCTB of the thoracic spine. The only symptom upon presentation was progressive back pain with pain radiating to the chest. Magnetic resonance imaging showed that the soft tissue mass extended posteriorly into the spinal canal, causing severe spinal cord compression. We initially treated this case with Decadron (Fresenius kabi, Bad Homburg vor der Hohe, Germany) for 1 week. This led to a reduction of tumor size and decompression of the spinal cord. To the best of our knowledge, there have been no prior reports of primary GCTB sensitive to steroid therapy within the existing literature.

Updates in Primary Bone Tumors: Current Challenges and New Opportunities in Cytopathology

The review summarizes the current diagnostic challenges in fine-needle aspiration of primary bone tumors, with focus on the application of new molecular and immunohistochemical techniques in the diagnosis of giant cell-rich neoplasms, chondrosarcomas, and notochordal tumors.

Clinical significance of decreased programmed cell death 4 expression in patients with giant cell tumors of the bone

Programmed cell death 4 (PDCD4) has been recognized as a novel tumor suppressor gene, which inhibits the activation and translation of activator protein (AP)-1. Dysregulated expression of PDCD4 is also involved in various human tumors and is linked to tumor progression and development. However, the function and clinical implication of PDCD4 in giant cell tumors of the bone (GCTBs) has not been previously investigated. In the present study, PDCD4 expression was determined in 83 samples of GCTBs at mRNA and protein levels by quantitative reverse transcription-polymerase chain reaction, western blotting and immunohistochemistry. The results demonstrated that PDCD4 mRNA expression was reduced in 63% of GCTB samples (17/27) and protein expression was decreased in 65% of samples (54/83), compared with adjacent non-tumor tissues. Furthermore, decreased expression of PDCD4 was significantly associated with certain clinicopathological characteristics, including the Campanacci grade and recurrence. A strong negative correlation was determined between PDCD4 expression and the Ki-67 positive rate in GCTBs (r=−0.6392; P<0.001). The results of the present study suggest that PDCD4 may serve a role in the malignant progression of human GCTBs and may be an important prediction factor for prognosis.

Prognosis of metastatic giant cell tumor of bone in the pre-denosumab era. A systematic review and a meta-analysis

Background

Data on long-term prognosis of metastatic GCT (mGCT) is scant. The frequency of spontaneous regressions (SRs) is unknown. We aimed to estimate the prognosis of mGCT.

Methods

We searched electronic scientific literature databases and generic Internet from January 1980 to August 2017. After identifying eligible studies we performed descriptive analyses and meta-analyses to estimate overall survival (OS), disease specific survival (DSS) and frequency of SRs in the years before the widespread use of denosumab. We performed pre-specified subgroup analyses of studies published before and after 2000 and of those with more and less than 10 years of follow-up.

Results

After retrieving and combining data from 26 relevant retrospective case-series totaling 242 patients with a median follow-up of 6.9 years, the estimated pooled OS was 86.9% (95% CI 78.0-94.2). Pooled DSS was 88.0% (95% CI 79.7-94.7). SRs were observed in 4.5% of patients. In the subgroup of studies published after 2000 mGCT was the only cause of death of affected subjects. In case-series with a follow-up longer than 10 years pooled DSS was 69.7% (95% CI 25.5-99.8).

Conclusions

To our knowledge this is the first study to derive estimated pooled OS and DSS of mGCT based on a large dataset. SRs were not exceptional phenomena. In a long run the disease could impact in a significant way on the life expectancy of affected subjects.

Left orbital roof giant cell tumor of bone: A case report

Background

Giant cell tumor of bone originating from the connective tissue within the bone marrow is benign but locally aggressive lesion. In all, 90% of the cases involve the epiphysis of long bones and less than 2% involve the skull. Giant cell tumors of the skull occur most frequently in the sphenoid and temporal bones, and very rarely in the ethmoid, frontal, parietal, and occipital bones. We would like to share a case of giant cell tumor of bone arising from the left orbital roof with involving ethmoid sinus, which was diagnosed to be a meningioma before surgery.

Case Description

A 32-year-old lady presented to us with the chief complain of left proptosis, diplopia, and left eye soreness without decline of visual acuity for about 2 months. Her orbital magnetic resonance imaging (MRI) disclosed a mass lesion located in the left frontal base, orbital roof, and upper medial orbital region with adjacent dural-tail sign favoring meningioma. She underwent a left supraorbital pterional craniotomy with the gross total removal of tumor and dura reconstruction. Histology examination of the tumor showed a picture of giant cell tumor of bone. Considering giant cell tumor of bone is locally aggressive, postoperative adjuvant therapy with Denosumab was introduced after full explanation.

Conclusion

Standard treatments of skull-base giant cell tumors have yet to be established due to small number of cases reported in the literature. The standard treatment of giant cell tumor of bone is complete resection of the tumor.

Immunohistochemistry for histone H3G34W and H3K36M is highly specific for giant cell tumor of bone and chondroblastoma, respectively, in FNA and core needle biopsy

BACKGROUND

Diagnosing giant cell-rich bone tumors can be challenging on limited biopsies. H3 histone family member 3A (H3F3A) (G34W/V/R/L) mutations are present in the majority of giant cell tumors (GCTs) of bone and H3 histone family member 3B (H3F3B) (K36M) mutations are present in nearly all chondroblastomas, but are absent in histologic mimics. Mutation-specific immunohistochemistry (IHC) is highly specific for GCT and chondroblastoma in surgical excisions. The objective of the current study was to validate H3G34W and H3K36M IHC in the diagnosis of giant cell-rich bone tumors on fine-needle aspiration and core needle biopsy specimens.

METHODS

IHC was performed using monoclonal antibodies against histone H3.3 G34W and K36M in GCTs of bone (26 cases, including 2 malignant cases), GCT of Paget disease (1 case), chondroblastoma (8 cases), aneurysmal bone cyst (7 cases), and osteosarcoma (13 cases) with available fine-needle aspiration and/or core needle biopsy specimens from 2 institutions. H3F3A and H3F3B Sanger sequencing was performed on all 4 H3G34W IHC-negative GCTs.

RESULTS

IHC for H3G34W was positive in 22 of 26 GCTs (85%) and negative in all histologic mimics. IHC for H3K36M was positive in all 8 chondroblastomas and negative in all histologic mimics. IHC results were concordant between biopsy and surgical specimens in 152 of 158 samples (96%). Sequencing identified alternate H3F3A G34L and G34V mutations in 1 IHC-negative GCT each, but no mutation was found in the remaining 2 cases.

CONCLUSIONS

H3G34W and H3K36M IHC is highly specific for GCT and chondroblastoma, respectively, among giant cell-rich bone tumors, and is useful for confirming the diagnosis in limited biopsies. The presence of alternate H3F3A mutations accounts for the H3G34W IHC negativity in a subset of GCT of bone cases. Cancer Cytopathol 2018. © 2018 American Cancer Society.

Giant Cell Tumor of Bone Presenting as Left Posteromedial Chest Wall Tumor

Giant cell tumor is a relatively uncommon bone tumor rarely originating from the chest wall. Given its proximity to vital structures in the thoracic cavity, treatment options may be challenging. We report the case of a patient with a giant cell tumor of the posterolateral chest wall with invasion of the thoracic spine treated with neoadjuvant denosumab, followed by surgical resection.

Giant cell tumours of bone treated with denosumab: histological, immunohistochemical and H3F3A mutation analyses

AIMS

Denosumab, a human monoclonal antibody directed against the receptor activator of nuclear factor-κB ligand (RANKL), is a therapeutic agent for giant cell tumour of bone (GCTB). Although some studies have reported that denosumab shrinks tumours and induces bone formation, the actual effects of RANKL suppression on GCTB remain unclear. A mutation in the H3 histone family member 3A gene (H3F3A) was recently identified as a genetic signature for GCTB. The aim of this study was to investigate the histopathological features and H3F3A mutation status of GCTBs treated with denosumab.

METHODS AND RESULTS

Nine biopsy-diagnosed patients with GCTB, who underwent curettage after neoadjuvant denosumab therapy, were reviewed. Immunohistochemistry for NFATc1 (an osteoclast marker), RUNX2 (an osteoblast marker) and histone H3.3 G34W (G34W, a GCTB marker) was performed; furthermore, H3F3A mutation status was examined with direct sequencing. Before therapy, GCTBs comprised NFATc1+ and RUNX2+ cells. All cases were G34W+ and contained H3F3A mutations. After therapy, the osteoclast-like giant cells disappeared. Areas of slender spindle cell proliferation and reticular woven bone that were NFATc1- and RUNX2+ replaced the lesions in various proportions. However, all post-therapy lesions still contained many G34W+ cells and harboured H3F3A mutations. Immunofluorescence double staining revealed that RUNX2+ mononuclear cells coexpressed G34W in pre-therapy and post-therapy lesions. Two patients experienced radiologically detected local recurrence within 2 years.

CONCLUSIONS

Denosumab therapy effectively decreases the number of osteoclastic cells in GCTBs. However, the neoplastic cells with H3F3A mutation survive denosumab treatment and undergo dramatic histological changes in response to this agent.

Pathologic conditions of hard tissue: role of osteoclasts in osteolytic lesion

Hard tissue homeostasis is regulated by the balance between bone formation by osteoblasts and bone resorption by osteoclasts. This physiologic process allows adaptation to mechanical loading and calcium homeostasis. Under pathologic conditions, however, this process is ill-balanced resulting in either over-resorption or over-formation of hard tissue. Local over-resorption by osteoclasts is typically observed in osteolytic metastases of malignancies, autoimmune arthritis, and giant cell tumor of bone (GCTB). In tumor-related local osteolysis, tumor-derived osteoclast-activating factors induce bone resorption not by directly acting on osteoclasts but by indirectly upregulating receptor activator of NFκB ligand (RANKL) on osteoblastic cells. Similarly, synovial tissue in the autoimmune arthritis model does overexpress RANKL and contains numerous osteoclast precursors, and like a landing craft, when it comes in contact with eroded bone surfaces, osteoclast precursors are immediately polarized to become mature osteoclasts, inducing rapidly progressive bone destruction at a late stage of the disease. GCTB, on the other hand, is a common primary bone tumor, usually arising at the metaphysis of the long bone in young adults. After the discovery of RANKL, the concept of GCTB as a tumor of RANKL-expressing stromal cells was established, and comprehensive exosome studies finally disclosed the causative single-point mutation at histone H3.3 (H3F3A) in stromal cells. Thus, osteolytic lesions under various pathological conditions are ultimately attributable to the overexpression of RANKL, which opens up a common, practical and useful therapeutic target for diverse osteolytic conditions.

Denosumab for the treatment of bone disease in solid tumors and multiple myeloma

Bone is a common site for malignant involvement, either as a site of metastasis, especially in breast or prostate cancer, or as a defining characteristic of the disease, as in multiple myeloma. Bone disease is a major source of morbidity, and half of patients with bone involvement develop skeletal-related events such as pathological fractures or cord compression requiring surgery and/or radiation. Skeletal involvement also increases mortality, as pathologic fractures increase the risk of dying by 20-40%. Osteoclast inhibition with bisphosphonates such as zoledronic acid and recently denosumab has been a significant improvement for bone disease. This review will focus on denosumab in the treatment of bone metastases and highlight the recent findings in multiple myeloma.

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.

Borderline Sarcomas and Smooth Muscle Tumours of Uncertain Malignant Potential

Borderline sarcomas and smooth muscle tumours of uncertain malignant potential (STUMP) have an unpredictable clinical behaviour with frequent local recurrences and rarely, metastases. We review the current management of common subtypes of borderline sarcomas and STUMP.

1H NMR metabolomic signatures related to giant cell tumor of the bone

¹H NMR metabolomic profiling for giant cell tumor of the bone.