Giant cell tumour of bone

Denosumab as treatment of central giant cell granuloma of the jaws. a scoping review

Denosumab has been considered a treatment option for Central Giant Cell Granuloma (CGCG) a benign locally aggressive osteolytic lesion of the jaws. This study aimed to perform a scoping review of CGCG treated with Denosumab. The research question was: What is Denosumab's effectiveness in treating CGCG of the jaws? Studies that used Denosumab as a treatment for CGCGs in the jaws were selected following PRISMA-ScR guidelines, using Pubmed/Medline, Scopus, and Springer Link databases, among others. Demographics, clinical information, dosing, efficacy, adverse drug reactions (ADRs), and imaging tests used to assess the evolution of the lesions were extracted. Twenty-one studies were selected. Sixty patients with a mean age of 23.2 years were treated with Denosumab, 42% with 120 mg subcutaneously monthly, additional doses on days 1, 8, and 15 for month 1 in adults. In children, dosing was adjusted by weight to 60 or 70 mg. To avoid ADRs 500 mg of calcium and 400 IU of vitamin D orally were used. Initial effective response was reported after 1-3 months, with recurrence of 19.6% and ADRs in 74% of cases. Denosumab is effective for CGCG with monthly subcutaneous doses of 120 mg, 60 or 70 mg in patients < 45 or 50 kg for ≥ 12 months with calcium and vitamin D supplementation until remission changes are observed. Extensive or refractory lesions were the main indications. Common ADRs were hypo and hypercalcemia. Further studies are needed to define dose and supplementation protocols to avoid ADRs during and after therapy.

Proximal Tibia Tumour Location and Curettage Are Major Risk Factors of Local Recurrence in Giant Cell Tumour of Bone

Giant cell tumour of bone (GCTB) is one of the most common local aggressive tumourous lesions with a wide variety of biological behaviour. However, there are no clear indicative criteria when choosing the type of procedure and the complication rates remain high, especially in terms of local recurrence. The purpose of the study was to (1) identify the main risk factors for local recurrence, (2) evaluate the recurrence-free survival in dependence on neoadjuvant denosumab use and the type of procedure, and (3) compare the functional outcomes after curettage and en bloc resection. The group included 102 patients with GCTB treated between 2006 and 2020. The mean age of patients was 34.4 years (15-79). The follow-up period was 8.32 years (2-16) on average. Local recurrence occurred in 14 patients (29.8%) who underwent curettage and in 5 patients (10.6%) after en bloc resection. Curettage was shown to be a factor in increasing recurrence rates (OR = 3.64 [95% CI: 1.19-11.15]; p = 0.023). Tibial location was an independent risk factor for local recurrence regardless of the type of surgery (OR = 3.22 [95% CI: 1.09-9.48]; p = 0.026). The recurrence-free survival rate of patients treated with resection and denosumab was higher compared to other treatments at five years postoperatively (p = 0.0307). Functional ability and pain as reported by patients at the latest follow-up were superior after curettage compared to resection for upper and lower extremity (mean difference: -4.00 [95% CI: -6.81 to -1.18]; p < 0.001 and mean difference: -5.36 [95% CI: -3.74 to -6.97]; p < 0.001, respectively). Proximal tibia tumour location and curettage were shown to be major risk factors for local recurrence in GCTB regardless of neoadjuvant denosumab treatment. The recurrence-free survival rate of patients treated with resection and denosumab was higher compared to other treatments. The functional outcome of patients after curettage was better compared to en bloc resection.

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

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

A Tertiary Care Centre Experience of Recurrent Giant Cell Tumor Around the Knee Joint

Introduction: Giant cell tumor (GCT) is a benign but locally aggressive bone tumor. It has a peak incidence between 30-40 years with a predilection for the epiphyseal/metaphyseal region of bone. The most common locations for bone GCT are the distal femur, proximal tibia, distal radius, and sacrum in decreasing order.

Material and Methods: In this retrospective study, 22 patients (13 females and nine males) with recurrent giant cell tumors around the knee joint between 2009-2022, with a mean age of 30.2 years (range: 18-55) were included. The patients were followed up monthly for three months, three-monthly for the next two years, six-monthly for the next five years, and thereafter, yearly. The mean follow-up period was 36.97 months (range 23-120 months).

Results: There were 19 recurrences after curettages and three after resections. Re-extended curettage was done in 17 cases and the resultant cavities were filled with autologous bone grafts in six and with polymethyl methacrylate (PMMA) cement in the other 11 cases. Reconstruction with megaprosthesis was done in two patients whereas knee arthrodesis was done in two patients after wide resection. The average Musculoskeletal Tumor Society (MSTS) score of our series of 22 patients was 23.1 (Range: 19-30).

Conclusion: Campanacci grade 1 and 2 lesions can be successfully treated with extended curettage and bone grafting/bone cementing. For patients with grade 3 lesions, there are two options available according to the financial status of the patient; the first option is reconstruction with prosthesis and the other option is arthrodesis.

Outcome of Reoperation for Local Recurrence Following En Bloc Resection for Bone Giant Cell Tumor of the Extremity

En bloc resection is typically performed to treat giant cell tumors of bone (GCTB), particularly when curettage can be challenging owing to extensive bone cortex destruction with soft tissue extension. Few reports have addressed the clinical outcomes after reoperation for local recurrence in patients with GCTB who underwent en bloc resection. In this multicenter retrospective study, we investigated local recurrence, distant metastasis, malignant transformation, mortality, and limb function in patients treated for local recurrence following en bloc resection for GCTB. Among 205 patients who underwent en bloc resection for GCTB of the extremities between 1980 and 2021, we included 29 with local recurrence. En bloc resection was performed for large tumors with soft tissue extension, pathological fractures with joint invasion, complex fractures, and dispensable bones, such as the proximal fibula and distal ulna. Local re-recurrence, distant metastasis, malignant transformation, and mortality rates were 41.4% (12/29), 34.5% (10/29), 6.9% (2/29), and 6.9% (2/29), respectively. The median Musculoskeletal Tumor Society score was 26 (interquartile range, 23–28). The median follow-up period after surgery for local recurrence was 70.1 months (interquartile range, 40.5–123.8 months). Local recurrence following en bloc resection for GCTB could indicate an aggressive GCTB, necessitating careful follow-up.

Bone Turnover Marker (BTM) Changes after Denosumab in Giant Cell Tumors of Bone (GCTB): A Phase II Trial Correlative Study

Background: Giant cell tumors of bone (GCTB) are osteolytic tumors. Denosumab, a RANK-L inhibitor, is approved for GCTB. Data on serum bone turnover marker (sBTM) changes are lacking. We present a phase II correlative study on sBTMs in GCTB patients treated with denosumab. Methods: All GCTB patients receiving denosumab within a multicentre, open-label, phase 2 study were enrolled. Serum levels of carboxyterminal-crosslinked-telopeptide of type I collagen (s-CTX), alkaline phosphatase (ALP), bone-alkaline phosphatase (bALP), parathyroid hormone (sPTH), and osteocalcin (OCN) were prospectively assessed (baseline, T0, 3 months, T1, 6 months, T2). The primary endpoint was assessment of sBTM changes after denosumab; the secondary endpoints were disease-free survival (DFS) and sBTM correlation. Results: In 54 cases, sBTMs decreased during denosumab treatment except for sPTH. With a median follow-up of 59 months, 3-year DFS was 65% (%CI 52−79), with a significantly worse outcome for patients with high (≥500 UI/mL) s-CTX at baseline, as compared to low s-CTX (<500 UI/mL) (3-year DFS for high CTX 45% (95%CI 23−67) vs. 75% (95%CI 59−91) for low s-CTX. Higher median ALP and s-CTX were found for patients with tumor size ≥ 5 cm (p = 0.0512; p = 0.0589). Conclusion: Denosumab induces ALP/OCN and s-CTX reduction. High baseline s-CTX identifies a group of patients at higher risk of progression of the disease.

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

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

Utility of intraoperative magnetic resonance imaging for giant cell tumor of bone after denosumab treatment: a pilot study

BACKGROUND

Giant cell tumor of bone (GCTB) is an intermediate but locally aggressive neoplasm. Current treatment of high-risk GCTB involves administration of denosumab, which inhibits bone destruction and promotes osteosclerosis. However, denosumab monotherapy is not a curative treatment for GCTB and surgical treatment remains required. Denosumab treatment complicates surgery, and the recurrence rate of GCTB is high (20%-30%).

PURPOSE

To examine the utility of intraoperative magnetic resonance imaging (iMRI) for detection and reduction of residual tumor after denosumab treatment and to investigate the utility of iMRI, which is not yet widely used.

MATERIAL AND METHODS

We enrolled five patients who received denosumab for a median period of eight months (range 6-12 months). Surgery was performed when the degree of osteosclerosis around the articular surface was deemed appropriate. We performed iMRI using a modified operation table to identify residual tumor after initial curettage and evaluated the rate of detection of residual tumor by iMRI, intraoperative and postoperative complications, exposure time of iMRI, and operation time.

RESULTS

Suspected residual tumor tissue was identified in all five cases and was confirmed by histopathology after additional curettage. The rate of detection of residual tumor by iMRI was 100%. Residual tumor was located in sites which were difficult to remove due to osteosclerosis. The iMRI was performed safely and without trouble. During the median follow-up period of 10 months (range 6-24 months), no adverse events or recurrences occurred.

CONCLUSION

Intraoperative MRI could contribute to the reduction of residual tumor tissue and it may prevent recurrence of GCTB after denosumab therapy.

Malignant Giant Cell Tumor of Bone With a KRAS G12V Mutation

Malignant giant cell tumor of bone (GCTB) is a rare, aggressive, sarcoma occurring in adolescent and young adults. It is characterized by the presence of multinucleated giant cells and an aggressive clinical course. Because of the rarity of this tumor, no standard therapies have been identified. Current treatment regimens often include osteosarcoma chemotherapy protocols. We present a case of a malignant GCTB with a KRAS G12V mutation. This mutation is a known oncogenic driver that has not previously been reported on patients with malignant GCTB.

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

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

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

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

New Target for Precision Medicine Treatment of Giant-Cell Tumor of Bone: Sunitinib Is Effective in the Treatment of Neoplastic Stromal Cells with Activated PDGFRβ Signaling

Simple Summary

The purpose of this study was to analyze differential cell signaling in response to denosumab treatment to identify and subsequently inhibit molecular targets in the neoplastic stromal cell population, which poses a risk for tumor recurrence. Using phosphoprotein arrays, a distinct signaling profile was detected in GCTB tissues treated with denosumab, a specific RANKL antibody, which coincided with the RTK profile in derived cell lines. PDGFRβ was selected as a promising receptor target, and its inhibition by the small-molecule inhibitor sunitinib resulted in potent inhibition of cell proliferation in vitro. The addition of sunitinib to denosumab resulted in the disappearance of both multinuclear giant cells and neoplastic stromal cells, as reported here. Thus, sunitinib could become an effective addition to denosumab in the treatment of GCTB with activated PDGFRβ.

Abstract

Giant-cell tumor of bone (GCTB) is an intermediate type of primary bone tumor characterized by locally aggressive growth with metastatic potential. The aim of this study was to identify new druggable targets among the cell signaling molecules involved in GCTB tumorigenesis. Profiles of activated signaling proteins in fresh-frozen tumor samples and tumor-derived cell lines were determined using phosphoprotein arrays. Analysis of the obtained data revealed epidermal growth factor receptor (EGFR) and platelet-derived growth factor receptor beta (PDGFRβ) as potential targets, but only the PDGFR inhibitor sunitinib caused a considerable decrease in stromal cell viability in vitro. Furthermore, in the case of a 17-year-old patient suffering from GCTB, we showed that the addition of sunitinib to the standard treatment of GCTB with the monoclonal antibody denosumab resulted in the complete depletion of multinucleated giant cells and mononuclear stromal cells in the tumor tissue. To summarize, the obtained data showed that a specific receptor tyrosine kinase (RTK) signaling pattern is activated in GCTB cells and plays an important role in the regulation of cell proliferation. Thus, activated RTKs and their downstream signaling pathways represent useful targets for precision treatment with low-molecular-weight inhibitors or with other types of modern biological therapy.

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

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

Towards better understanding of giant cell granulomas of the oral cavity

Giant cell granulomas are enigmatic lesions of the oral cavity characterised by a peculiar combined proliferation of mononuclear and multinucleated giant cells in a mesenchymal stromal background. Central and peripheral giant cell granulomas may have similar pathogenesis and histology but differ in their location and biological behaviour. It is important to differentiate them from other giant cell lesions that can occur in the oral cavity, such as giant cell tumour of the bone, aneurysmal bone cyst, brown tumour of hyperparathyroidism, and giant cell lesions of Ramon syndrome, Noonan syndrome, neurofibromatosis and Jaffe-Campanacci syndrome. A recent insight into their molecular genetics and pathogenesis, with identification of KRAS, FGFR1 and TRPV4 mutations, allows for better diagnostic differentiation and opens the door to the use of pathway inhibitors in the treatment of recurrent or dysmorphic lesions. In this review, we provide an updated summary of the clinical and pathological features of oral cavity giant cell granulomas that help with their precise diagnosis and management.

Giant Cell Tumor of Bone: An Update

PURPOSE OF REVIEW

To highlight the new developments in the management of advanced giant cell tumor of bone, a rare locally aggressive benign tumor, which was traditionally managed with surgery alone by either curettage and local adjuvant therapy, wide resection, or marginal excision. Here, we review the current role of systemic therapy for management of locally advanced or metastatic giant cell tumor of bone (GCTB).

RECENT FINDINGS

The elucidation of the pathophysiology of giant cell tumor of bone, especially with regards to the role of nuclear factor kappa B ligand (RANKL), has led to the Food and Drug Administration (FDA) approval of denosumab in the management of locally advanced or metastatic GCTB. For advanced giant cell tumor where surgical resection alone can cause severe morbidity, the paradigm has shifted from local treatment alone to multidisciplinary management with the consideration of use of denosumab.

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.

Denosumab Therapy for Giant-cell Tumor of the Lumbar Spine: A Case Report and Immunohistochemical Examination

Introduction

Denosumab, a monoclonal antibody that inhibits the receptor activator of nuclear factor-kappa (RANK) ligand, has been reported to reduce tumor size and progression, promote bone mineralization reconstruction, and increase bone density in patients with giant-cell tumor of bone (GCTB). However, information regarding the histopathological findings of spinal GCTB following denosumab therapy and the time course of the treatment is limited.

Case Report

We report the case of a 58-year-old woman with progressive low back pain for 3 months before admission. Radiological and histological examinations revealed L4 GCTB. The patients received 10 courses of denosumab, and the tumor was subsequently resected. The therapy resulted in reduction of tumor mass and replacement of the lesions with bone tissue, particularly at the extravertebral and intracanal mass lesions. Histological examination of resected vertebra revealed a notable decrease in the number of RANK-positive and cyclooxygenase-2-positive cells. However, few RANK-positive cells were present around the woven bone.

Conclusion

Denosumab therapy for spinal GCTB is effective for reducing the tumor stage, surgical complications, and neurological impairment progression; however, it does not lead to total elimination of GCT cells, and careful consideration is needed in terms of the surgical procedure and post-operative denosumab therapy.

Giant cell tumor stromal cells: osteoblast lineage-derived cells secrete IL-6 and IL-10 for M2 macrophages polarization

Background

The giant cell tumor (GCT) is a benign tumor which consists of three types cells: mononuclear histiocytic cells (MNHCs), multinuclear giant cells (MNGCs), and GCT stromal cells (GCTSCs). Numerous studies claim that GCTSCs have mesenchymal stem cells (MSCs) characters and play an important role in osteoclastogenesis; however, there are no research studies concerning macrophage polarization among GCT, which can be regarded as an ingredient for tumor aggression.

Method

We tested the effect of GCTSCs from three GCT samples which were collected from patients on proliferation, apoptosis and polarization of macrophage.

Result

In this article, we verified that GCTSCs expressed MSCs markers and had higher proliferation and relative lower differentiation abilities compared with BMMSCs. What's more, we found a higher proportion of M2 macrophages among neoplasm. Co-culturing GCTSCs with macrophages resulted in prominent macrophage M2 polarization and increased the release of IL-6 (Interleukin-6) and IL-10 (Interleukin-10)from GCTSCs. In conclusion, GCTSCs, as originating from MSCs, can secret IL-6 and IL-10, which may play a significant role in macrophage M2 polarization.

Clinical, radiological and pathological outcomes following treatment of primary giant cell tumour of bone with Denosumab

BACKGROUND

Giant cell tumour of bone (GCTOB) is a relatively uncommon, benign, but locally aggressive neoplasm. Denosumab is a fully human monoclonal antibody with inhibitory effects on receptor activator of nuclear factor kappa-B ligand that has shown early promise as a possible treatment adjuvant for GCTB. However, much is still unknown about its current indications, long-term effects, the potential risk for rapid relapse and its involvement in sarcomatous transformation.

METHODS

We analysed the outcomes of 154 patients with GCTOB. We assessed clinical outcomes via local recurrence free-survival, metastatic free-survival and sarcomatous transformation between those treated without Denosumab and those with neo-adjuvant Denosumab. Our radiological and pathological outcomes were assessed through independent specialist reviews.

RESULTS

Four (19.0%) patients of the neo-adjuvant group had local recurrence of disease versus 16 (12.0%) patients in the surgery alone group; this results in a 3.62 times increased likelihood of developing local recurrence (P = 0.030). The median time to local recurrence was shorter for the neo-adjuvant group (421.5 days versus 788.5 days) (P = 0.01). There was no difference between Denosumab and the surgery groups in terms of metastatic disease (P = 0.45). Two patients in our cohort with GCTOB developed sarcomatous transformation, both were treated with Denosumab.

CONCLUSION

Our use of Denosumab tended to be for those patients who had surgically difficult tumours to halt the progression and allow easier resections. Of concern we noted a trend towards increasing recurrence rates with the potential risk for rapid relapse. Furthermore, two cases experienced sarcomatous transformation, which is a growing area of concern within the literature.

The two faces of giant cell tumor of bone

Giant cell tumor (GCT) is a bone-destructive benign neoplasm characterized by distinctive multinucleated osteoclast-like giant cells with osteolytic properties distributed among neoplastic stromal cells. GCT is locally aggressive with progressive invasion of adjacent tissues and occasionally displays malignant characteristics including lung metastasis. GCT is characterized genetically by highly recurrent somatic mutations at the G34 position of the H3F3A gene, encoding the histone variant H3.3, in stromal cells. This leads to deregulated gene expression and increased proliferation of mutation-bearing cells. However, when GCT complicates Paget disease of bone (GCT/PDB) it behaves differently, showing a more malignant phenotype with 5-year survival less than 50%. GCT/PDB is caused by a germline mutation in the ZNF687 gene, which encodes a transcription factor involved in the repression of genes surrounding DNA double-strand breaks to promote repair by homologous recombination. Identification of these driver mutations led to novel diagnostic tools for distinguishing between these two tumors and other osteoclast-rich neoplasms. Herein, we review the clinical, histological, and molecular features of GCT in different contexts focusing also on pharmacological treatments.

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.

The reconstruction after en-bloc resection of giant cell tumors at the distal radius: A systematic review and meta-analysis of the ulnar transposition reconstruction technique

BACKGROUND

En-bloc resection of giant cell tumors (GCTs) of the distal radius remains the mainstay treatment for those with high-graded lesions. Several techniques have been described for reconstruction of the resected segment, of which transposition of the ipsilateral ulna is scarcely reported.

OBJECTIVES

To investigate the efficacy and safety of the different techniques of ulnar translocation following GCTs total resection.

METHODS

A systematic review and meta-analysis was conducted concerning the reported functional outcomes, including grip strength, range of forearm motion, functional scores, and new bone formation, as well as postoperative complications, such as delayed union, local recurrence and metastasis. The ranges of functional outcomes were reviewed and the pooled prevalence rates of complication and their respective 95% confidence intervals (95% CIs) were computed.

RESULTS

In a total of 12 studies, 90 patients (51.1% males, 84.8% had Campanacci grade III tumors) underwent five different reconstruction techniques. As compared to the normal side, the mean grip strength in the affected side ranged between 59 and 71%. The average union time was 1-8 months, while delayed union was reported in 50% (95% CI, 15.35 to 84.65) of patients whom their grafts were fixed with Steinmann pins. The shortest union time, the highest forearm supination and pronation degrees, new bone formation at the ulnar stump, and the highest functional scores were reported following a modified distal radius plate technique. Using a dynamic compression plate and a clover leaf plate provided lower, but considerable, functional outcomes.

CONCLUSION

Ulnar translocation following GCT en-bloc resection warrants additional investigation in large cohorts and well-designed studies to corroborate the promising outcomes presented in this review.

Spectrum of histological features of Denosumab treated Giant Cell Tumor of Bone; potential pitfalls and diagnostic challenges for pathologists

OBJECTIVES

Denosumab is Receptor Activator of Nuclear factor Kappa-B Ligand (RANKL) inhibitor which is being used in the treatment of locally advanced, recurrent and metastatic Giant Cell Tumor of Bone (GCTB). It causes reduction in monocyte recruitment and Osteoclast-Like Giant Cell (OLGC) formation which limits bone destruction. After Denosumab treatment, GCTB exhibit diverse morphological features which can pose diagnostic challenge. Our aim was to study the spectrum of histologic features seen in Denosumab treated GCTB which could be helpful in establishing correct diagnosis.

METHODS

We retrieved and reviewed H&E stained microscopic glass slides of 38 GCTB cases who received Denosumab as neoadjuvant treatment. These cases were treated at different institutes and diagnosed at our institute between January 2017 and October 2019. Morphologic features such as presence of residual OLGC, appearances of mononuclear stromal and bony components were assessed along with other non-specific features.

RESULTS

Patients' median age was 29 years. Male to female ratio was 1.53:1. Femur was the most commonly involved bone. Microscopically, peripheral shell of reactive bone was observed in all cases. In 20 (52.6%) cases, there was complete elimination of OLGC. Mononuclear stromal cells were predominantly bland spindle shaped and arranged in fascicular and storiform patterns. Focal atypia was noted in 3 cases. Bony component manifested as trabeculae of woven bone with osteoblastic rimming and immature trabeculae of unmineralized osteoid with haphazardly present osteoblasts. Spectrum of stromal changes included cystic spaces, foamy macrophages, inflammatory infiltrate, hemangiopericytoma-like (HPC-like) vessels, hyalinization, edematous areas and hemosiderin pigment. The tumors showed areas which resembled other bony and soft tissue lesions such non-ossifying fibroma, fibrous dysplasia, osteoblastoma, sclerosing epithelioid fibrosarcoma and osteosarcoma.

CONCLUSION

Denosumab treatment induces a variety of changes in GCTB. Clinical history and knowledge of these features are necessary for excluding differential diagnoses and avoiding misdiagnosis.

Third-Ray and Capitate Resection with Limited Midcarpal Fusion for Recurrent Giant Cell Tumor: A Case Report

CASE

We describe a 23-year-old man who had multiple recurrences of a giant cell tumor (GCT) of the third metacarpal. Initial treatments consisted of curettage without the use of an adjuvant and bone-grafting. At the time of the latest recurrence, the lesion had extended into the capitate and the trapezoid. Treatment included third-ray resection and limited midcarpal fusion. No local recurrence was identified at more than 1 year after surgery.

CONCLUSION

GCTs of the hand should be aggressively treated, but care should be taken to preserve function whenever possible.

Image-Guided Percutaneous Management of Skull and Spine Giant Cell Tumors: Case Report of 2 Challenging Cases Successfully Treated with Doxycycline Sclerotherapy

Background

A giant cell tumor (GCT) of bone is a benign, locally aggressive tumor that is often challenging to treat. When complete resection is not possible, curettage with or without adjuvants is the most common treatment. The high frequency of local recurrence and risk of injury to adjacent structures can limit this surgical approach, especially with skull and spine lesions.

Case Description

We report 2 cases of axial skeleton GCTs, 1 in the skull of a 58-year-old woman in whom operative management failed, who experienced local recurrence, and 1 in the cervical spine of an 8-year-old girl that grew extracompartmentally to surround her brachial plexus. Both patients were referred to us because of the surgically challenging nature of their tumors. After completion of the same percutaneous doxycycline sclerotherapy protocol previously described for aneurysmal bone cysts (ABCs), both patients were considered cured and were able to return to normal activities without loss of pretreatment function. After 4 and 10 years of follow-up, respectively, there has been no tumor recurrence in either patient.

Conclusions

We successfully treated 2 patients with very challenging axial skeleton GCTs using a percutaneous doxycycline sclerotherapy protocol previously shown to have success with ABCs. We believe that this minimally invasive procedure should be considered a potential alternative treatment for GCTs, especially axial skeleton lesions, which may not be easily approached with standard surgical techniques.

Axial giant cell tumor - current standard of practice

Giant cell tumors of bone are relatively rare in the axial skeleton, accounting for approximately 6.7% of all cases. Due to their anatomical complexity, difficult access and proximity to vital neurovascular structures, management of these tumors poses a huge challenge on the treating surgeon. Several data series reported on axial GCTB involve short series of limited cases with varied methods used in their local control due to which, proper guidelines are unavailable for the management of such difficult cases. Though the present data support the use of denosumab for effective management of these lesions but there is varied consensus on dosage and duration of treatment. This review article summarizes the basic features and treatment modalities related to axial GCTB stressing on multidisciplinary approach to achieve optimum outcomes.

Histopathology of giant cell tumors of the bone: With special emphasis on fibrohistiocytic and aneurysmal bone cyst like components

Objective

The aim of this study was to define histopathological features of giant cell tumor of bone, especially accompanying fibrohistiocytic or aneurysmal bone cyst like components, in the light of our institutions experience.

Methods

A total of 120 cases (64 females and 56 males; mean age: 36.2 (12–80)) with ‘GCT’ diagnosed between the years 1996–2016 were included in this retrospective analysis. Cases were evaluated according to clinical features such as age, gender, localization, recurrence, metastasis and histopathological features.

Results

Tumors were localized most frequently at proximal tibia and distal femur, respectively. In 11 cases areas rich in fibrohistiocytic component and in 20 cases aneurysmal bone cyst like component were observed. In 2 cases both components were present. Twenty three cases recurred. In 1 case which was primarily located at calcaneus, tumor metastasized to lung 4 years later during follow-up.

Conclusion

GCT can be confused with other tumor or tumor-like lesions involving giant cells. Secondary changes such as fibrohistiocytic or aneurysmal bone cyst-like components and coagulation necrosis were frequently seen in conventional giant cell tumor of bone. For tumors having prominent fibrohistiocytic and/or aneurysmal bone cyst-like components, in order to detect characteristic areas representing GCT, additional sampling is essential. Although secondary histopathological changes do not appear to affect clinical outcome, these features are important in differential diagnosis. Approximately one fifth of GCT cases show recurrence and sacrum and foot bones were the most frequent sites for recurrence.

Level of evidence

Level IV, diagnostic study.

The Intrinsic and Extrinsic Implications of RANKL/RANK Signaling in Osteosarcoma: From Tumor Initiation to Lung Metastases

Background: Osteosarcoma is the most frequent form of malignant pediatric bone tumor. Despite the current therapeutic arsenal, patient life-expectancy remains low if metastases are detected at the time of diagnosis, justifying research into better knowledge at all stages of osteosarcoma ontogenesis and identification of new therapeutic targets. Receptor Activator of Nuclear factor κB (RANK)expression has been reported in osteosarcoma cells, raising the question of Receptor Activator of Nuclear factor κB Ligand (RANKL)/RANK signaling implications in these tumor cells (intrinsic), in addition to previously reported implications through osteoclast activation in the tumor microenvironment (extrinsic). Methods: Based on in vitro and in vivo experimentations using human and mouse osteosarcoma cell lines, the consequences on the main cellular processes of RANK expression in osteosarcoma cells were analyzed. Results: The results revealed that RANK expression had no impact on cell proliferation and tumor growth, but stimulated cellular differentiation and, in an immune-compromised environment, increased the number of lung metastases. The analysis of RANKL, RANK and osteoprotegerin (OPG) expressions in biopsies of a cohort of patients revealed that while RANK expression in osteosarcoma cells was not significantly different between patients with or without metastases at the time of diagnosis, the OPG/RANK ratio decreased significantly. Conclusion: Altogether, these results are in favor of RANKL-RANK signaling inhibition as an adjuvant for the treatment of osteosarcoma.

Preoperative Denosumab With Curettage and Cryotherapy in Giant Cell Tumor of Bone: Is There an Increased Risk of Local Recurrence?

BACKGROUND

Denosumab is a monoclonal RANKL antibody, which was originally introduced for the treatment of osteoporosis and bone metastases from solid tumors, but more recently has been used for treatment of giant cell tumor of bone (GCTB). In GCTB, denosumab has been used as a single agent in patients with inoperable tumors; it also has been used before surgery in some patients with the aim to downstage the tumor to facilitate a joint-preserving procedure (curettage) rather than a resection. However, few studies are available evaluating the benefits and risks of denosumab for the latter indication.

QUESTIONS/PURPOSES

(1) Does preoperative treatment with denosumab reduce the risk of local recurrence in patients treated for GCTB? (2) Are there adverse effects of short-term denosumab use before surgery and, if so, what are they?

METHODS

All patients with a diagnosis of GCTB surgically treated at our institution from June 2009 to June 2016 with curettage and cryotherapy were retrospectively evaluated to compare patients treated with curettage alone versus patients treated with curettage after preoperative therapy with denosumab. During that period, we treated 97 patients for GCTB; 30 patients were excluded because they received a resection; 34 patients were excluded because they received curettage without cryotherapy. Of the remaining 33 patients, four were excluded because they received denosumab only after surgery, one because she received zoledronic acid, one because she received a curettage after her refusal of a resection that was the advised procedure, two because they were lost to followup early, and four because they were treated for recurrence rather than a new diagnosis of GCTB. The remaining 21 patients were included. Twelve lesions had been treated with surgery after denosumab and nine with surgery alone. During the study period, we preferentially used denosumab for the more aggressive-looking lesions. After curettage, cryotherapy of the residual bone walls was performed with argon cryoprobes to -150° C after pouring gel into the cavity, and we then used cement (17 patients) or morcellized allograft (four patients). Tumors were Campanacci Grade 3 in eight of 12 patients in the denosumab group and in two of nine patients in the surgery-only group (p = 0.08), but the extent of epiphyseal juxtaarticular bone involvement was not different between the groups with the numbers available. Median followup was 39 months (range, 14-55 months) in the denosumab group and 27 months (range, 18-92 months) in the surgery-only group. We used chart review to record the proportion of patients in each treatment group who had a local recurrence and to tally adverse events.

RESULTS

With the numbers available, there was no difference in the proportion of patients experiencing a recurrence (five of 12 in the denosumab group and one of nine in the surgery-only group; p = 0.18). We found no adverse effects associated with denosumab either during or after treatment; specifically, we found no alterations in electrolyte levels, blood count, or liver and renal function parameters. In this small series, no patient has developed osteonecrosis of the jaw.

CONCLUSIONS

In this small series, use of denosumab before surgery for GCTB appeared to allow the reforming of a bone peripheral rim around the tumor, perhaps facilitating curettage rather than osteoarticular resection in some patients. However, we did not observe a decrease in the risk of local recurrence with the use of denosumab, suggesting that it may not decrease the aggressiveness of the disease; according to our preliminary results, we cannot exclude that the rate of local recurrence could be even higher after curettage in denosumab-treated patients than in nontreated patients, and until or unless larger studies demonstrate such a reduction, primary intralesional surgery without denosumab seems more prudent when curettage is feasible at presentation. We did not observe any adverse effects with denosumab, but we caution readers that this study was underpowered to detect even relatively common complications and relatively large differences in the risk of local recurrence. Future studies should evaluate denosumab prospectively; given the relative rarity of this tumor, we suspect multicenter studies are needed to achieve this.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Denosumab treatment of inoperable or locally advanced giant cell tumor of bone - Multicenter analysis outside clinical trial

BACKGROUND

Giant cell tumor of bone (GCTB) is an osteolytic, locally aggressive, rarely metastazing bone tumor. This is a retrospective study evaluating a large series of GCTB patients treated with denosumab in routine practice in 6 European reference centers.

METHODS

Patients with locally advanced, unresectable or metastatic GCTB, treated with denosumab outside clinical trials were eligible. Primary end-point was progression-free survival (PFS) for all patients; secondary end-points were: type of surgery, relapse rate and event-free survival for patients after preoperative denosumab + surgery.

RESULTS

We identified 138 patients treated in the period 2011-2016. In 40/43 cases the diagnosis was confirmed by H3F3A gene mutation. Median follow-up time was 23 months (range 6-48). Primary tumor was located in lower limb (38%) - mostly in femur and tibia, in upper limb (34%), and in pelvis/axial skeleton/ribs (28%). 110 (80%) patients had primary tumors, 28 (22%) recurrent tumors after previous surgical procedures (+/- radiotherapy). 89/138 patients had locally advanced GCTB and underwent neoadjuvant denosumab. The median denosumab treatment duration was 8 months (median number of cycles 11), 98% had clinical benefit from therapy. 39 (44%) had wide en-bloc resection - WE (+implantation of the prosthesis in 17 cases), the other 50 (56%) cases had intralesional curettage - C. Progression after surgical treatment was observed in 19 patients, 16 of them after C (32%); 13 patients underwent denosumab re-challenge, and all responded. Two-year progression-free survival (PFS; from denosumab start) rate was 81%; 2-year EventFS (from surgery) was significantly better in WE group (93%) vs 55% in C group (p = 0.006). Treatment was well tolerated with only 2 cases of grade 3 toxicity and one osteonecrosis of the jaw.

CONCLUSION

Our retrospective study confirms that denosumab is extremely efficient in unresectable/metastatic disease as well as in a neoadjuvant setting. Our data confirm excellent efficacy and short-term tolerability of this drug. Our data suggest that neoadjuvant therapy with denosumab is the option for treatment of initially locally advanced tumors to facilitate complete surgical resection or avoid mutilating surgery. The risk of recurrences after curettage of GCTB following denosumab raises questions about the optimal management of such cases.

Giant cell tumour of the distal radius/ulna: response to pre-operative treatment with short-term denosumab

Background

Treatment of giant cell tumour of bone (GCTB) of the distal radius/ulna poses a surgical challenge, as complex reconstructive surgery may be required. This study evaluates the clinical, radiological and pathological findings in five cases of GCTB of the distal forearm where a 3 month course of denosumab was given prior to surgery.

Methods

Patients with biopsy proven distal forearm GCTB, treated for 3 months with denosumab, followed by salvage surgery (curettage and cementation) were included. Wrist pain and function were assessed using the modified Mayo Wrist Score (MMWS). Plain radiographs, MRI and PET/CT were performed pre-treatment and 2 months after initiation of denosumab therapy. Histological comparison was made between the original biopsy and surgical curettage specimens.

Results

Five patients with an average age of 25 years were included in the study. Improvement in wrist pain and function was seen in all patients with the average MMWS increasing from 30 pre-treatment to 85 at 3 months. Plain radiographs demonstrated marginal sclerosis in all cases with reconstitution of cortical and subarticular bone by 2 months; internal matrix sclerosis and osseous consolidation was more variable. Increased tumour heterogeneity and low signal were observed on T2-weighted MR images. PET/CT revealed a decrease in average SUV from 14.8 pre-treatment to 4.7 at 2 months. Histology showed disappearance of osteoclasts and increased fibro-osseous tissue. Denosumab treatment has the potential to facilitate salvage surgery, thus avoiding bone resection and graft reconstruction. A good outcome was achieved apart from local recurrence in one case. Follow up ranged from 17 to 54 months.

Conclusion

Distal forearm GCTB responds clinically, radiologically and histologically to a short course of pre-operative denosumab therapy, which has the potential to facilitate salvage surgery.

Denosumab as a Treatment Alternative for Central Giant Cell Granuloma: A Long-Term Retrospective Cohort Study

PURPOSE

Giant cell granuloma (GCG) of the jaw is a rare disease with high morbidity. Various treatment options have been discussed in the past. Since 2010, a pharmaceutical therapy with denosumab seems to have been successful for giant cell tumors of the femur. The authors hypothesized the equally successful use of denosumab for GCGs of the jaws.

MATERIALS AND METHODS

In the present retrospective cohort study, 5 patients with large GCGs of the jaws were treated with denosumab with a follow-up of 25 to 49 months. Frequent clinical follow-ups and a radiologic follow-up were performed and systematically analyzed.

RESULTS

All patients showed a curative treatment response and complete metabolic resolution of the GCGs under treatment with denosumab.

CONCLUSION

A brief review of the relevant literature and a detailed evaluation of current cases led to the conclusion that denosumab therapy should be considered a therapeutic option for large central GCGs of the jaws. The results of this study suggest denosumab is a successful treatment option. A treatment length no shorter than 12 months is recommended and monitoring of treatment response can be well managed by positron-emission tomographic computed tomography or magnetic resonance imaging.

Epidemiological and Clinical Features of Primary Giant Cell Tumors of the Distal Radium: A Multicenter Retrospective Study in China

Giant cell tumors of the distal radius are challenging for surgeons because they are associated with high recurrence rates and poor functional outcomes. Between June 2005 and October 2015, patients with primary giant cell tumors of the distal radius were recruited from seven orthopedic centers in China. The patients’ clinical features and demographic characteristics were obtained from medical records and reviewed retrospectively. Overall, 48 cases of giant cell tumors of the distal radius were assessed in this study. These patients were more likely to be between 20 and 40 years of age, to have a Campanacci grade of III, and to undergo a surgical style of resection. The prevalence of pathological fractures was 12.5% overall (20.0% in men and 4.3% in women). The prevalence of local recurrence was 30.0% overall (38.1% in men and 21.1% in women) during the average follow-up period of 62.5 months, with a pulmonary metastasis rate of 5.0%. Giant cell tumors of the distal radius were predominant in men and were more likely to recur locally than around the knee. These findings suggest that it is crucial to evaluate the optimal surgical approach for balancing local recurrence control and functional outcomes to reduce the disease burden.

Denosumab treatment for progressive skull base giant cell tumor of bone in a 14 year old female - a case report and literature review

Background

Giant cell tumor of bone (GCT) is a rare primary bone tumor, which can metastasize and undergo malignant transformation. The standard treatment of GCT is surgery. In patients with unresectable or metastatic disease, additional therapeutic options are available. These include blocking of the receptor activator of NF-kappa B ligand (RANKL) signaling pathway, which plays a role in the pathogenesis of GCT of bone, via the anti-RANKL monoclonal antibody denosumab.

Case Presentation

Herein we report on a female teenager who presented in a very poor clinical condition (cachexia, diplopia, strabismus, dysphonia with palsy of cranial nerves V, VI, VIII, IX, X, XI and XII) due to progressive disease, after incomplete resection and adjuvant radiotherapy, of a GCT which affected the cervical spine (C1 and C2) as well as the skull base; and who had an impressive clinical response to denosumab therapy. To the best of our knowledge, this is the youngest patient ever reported with a skull base tumor treated with denosumab.

Conclusion

In situations when surgery can be postponed and local aggressiveness of the tumor does not urge for acute surgical intervention, upfront use of denosumab in order to reduce the tumor size might be considered. Principally, the goal of denosumab therapy is to reduce tumor size as much as possible, with the ultimate goal to make local surgery (or as in our case re-surgery) amenable. However, improvement in quality of life, as demonstrated in our patient, is also an important aspect of such targeted therapies.

Electronic supplementary material

The online version of this article (doi:10.1186/s13052-017-0353-0) contains supplementary material, which is available to authorized users.

Supplemental Bone Grafting in Giant Cell Tumor of the Extremity Reduces Nononcologic Complications

BACKGROUND

Giant cell tumors (GCTs) are treated with resection curettage and adjuvants followed by stabilization. Complications include recurrence, fracture, and joint degeneration. Studies have shown treatment with polymethylmethacrylate (PMMA) may increase the risk of joint degeneration and fracture. Other studies have suggested that subchondral bone grafting may reduce these risks.

QUESTIONS/PURPOSES

Following standard intralesional resection-curettage and adjuvant treatment, is the use of bone graft, with or without supplemental PMMA, (1) associated with fewer nononcologic complications; (2) associated with differences in tumor recurrence between patients treated with versus those treated without bone grafting for GCT; and (3) associated with differences in Musculoskeletal Tumor Society (MSTS) scores?

METHODS

Between 1996 and 2014, 49 patients presented with GCT in the epiphysis of a long bone. Six patients were excluded, four who were lost to followup before 12 months and two because they presented with displaced, comminuted, intraarticular pathologic fractures with a nonreconstructable joint surface. The remaining 43 patients were included in our study at a mean followup of 59 months (range, 12-234 months). After resection-curettage, 21 patients were reconstructed using femoral head allograft with or without PMMA (JB) and 22 patients were reconstructed using PMMA alone (FRP, KSB); each surgeon used the same approach (that is, bone graft or no bone graft) throughout the period of study. The primary study comparison was between patients treated with bone graft (with or without PMMA) and those treated without bone graft.

RESULTS

Nononcologic complications occurred less frequently in patients treated with bone graft than those treated without (10% [two of 21] versus 55% [12 of 22]; odds ratio, 0.088; 95% confidence interval [CI], 0.02-0.47; p = 0.002). Patients with bone graft had increased nononcologic complication-free survival (hazard ratio, 4.59; 95% CI, 1.39-15.12; p = 0.012). With the numbers available, there was no difference in tumor recurrence between patients treated with bone graft versus without (29% [six of 21] versus 32% [seven of 22]; odds ratio, 0.70; 95% CI, 0.1936-2.531; p = 0.586) or in recurrence-free survival among patients with bone graft versus without (hazard ratio, 0.94; 95% CI, 0.30-2.98; p = 0.920). With the numbers available, there was no difference in mean MSTS scores between patients treated with bone graft versus without (92% ± 2% versus 93% ± 1.4%; mean difference 1.0%; 95% CI, -3.9% to 6.0%; p = 0.675).

CONCLUSIONS

Compared with PMMA alone, the use of periarticular bone graft constructs reduces postoperative complications apparently without increasing the likelihood of tumor recurrence.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Use of denosumab in recurrent chondroblastoma of the squamous temporal bone: a case report

Chondroblastoma is a rare, benign bone tumor that represents 1–2% of all primary bone tumors. Denosumab, a monoclonal antibody, has been demonstrated to inhibit the growth of giant cell tumors. We report a case of recurrent chondroblastoma of the squamous temporal bone that is currently suppressed with denosumab.

Treatment of a skull-base giant cell tumor with endoscopic endonasal resection and denosumab: case report

A 34-year-old man with a 1-week history of diplopia was referred to the authors' hospital. Neurological examination revealed left abducens nerve palsy. Computed tomography showed a lesion in the left sphenoid sinus involving the medial wall of the left internal carotid artery (ICA) and osteolytic change at the clivus bordering the lesion. Magnetic resonance imaging demonstrated an extensive soft-tissue mass occupying the left sphenoid sinus. Surgical intervention by the endoscopic transnasal method allowed most of the lesion to be removed. Only the portion attached to the medial wall of the ICA was not removed. Postoperatively, the lesion was diagnosed as a giant cell tumor (GCT) and the patient received 120 mg of subcutaneous denosumab every 4 weeks, with additional doses on Days 8 and 15 during the first month of therapy. MRI a week after starting denosumab revealed shrinkage of the initially fast-growing residual tumor. The patient was discharged upon completion of the third denosumab administration. GCT is an aggressive stromal tumor developing mainly in young adults. Complete resection is recommended for GCT in the literature. However, size and location of the CGT often limit this approach. Various adjuvant treatments for skull base GCTs have been reported, including radiation and chemotherapy. However, the roles of adjuvant therapies have yet to be clearly defined. Denosumab, a monoclonal antibody, was recently approved for GCT in several countries. Denosumab may permit less invasive treatments for patients with GCTs while avoiding deleterious outcomes, and may also limit disease progression and recurrence.

Immune Therapy for Sarcomas

Absolute lymphocyte count (ALC) recovery rapidly occurring at 14 days after start of chemotherapy for osteosarcoma and Ewing sarcoma is a good prognostic factor. Conversely, lymphopenia is associated with significantly decreased sarcoma survival. Clearly, the immune system can contribute towards better survival from sarcoma. This chapter will describe treatment and host factors that influence immune function and how effective local control and systemic interventions of sarcoma therapy can cause inflammation and/or immune suppression but are currently the standard of care. Preclinical and clinical efforts to enhance immune function against sarcoma will be reviewed. Interventions to enhance immune function against sarcoma have included regional therapy (surgery, cryoablation, radiofrequency ablation, electroporation, and radiotherapy), cytokines, macrophage activators (mifamurtide), vaccines, natural killer (NK) cells, T cell receptor (TCR) and chimeric antigen receptor (CAR) T cells, and efforts to decrease inflammation. The latter is particularly important because of new knowledge about factors influencing expression of checkpoint inhibitory molecules, PD1 and CTLA-4, in the tumor microenvironment. Since these molecules can now be blocked using anti-PD1 and anti-CTLA-4 antibodies, how to translate this knowledge into more effective immune therapies in the future as well as how to augment effectiveness of current interventions (e.g., radiotherapy) is a challenge. Barriers to implementing this knowledge include cost of agents that release immune checkpoint blockade and coordination of cost-effective outpatient sarcoma treatment. Information on how to research clinical trial eligibility criteria and how to access current immune therapy trials against sarcoma are shared, too.

Chemotherapy for Bone Sarcoma in Adults

The largest studies of chemotherapy for bone sarcomas are in the pediatric population. Although increasing age is often found to be an adverse prognostic factor in these clinical trials, few studies are aimed at assessing regimens specifically in the adult population. Osteosarcoma and Ewing sarcoma have peak incidences in the pediatric and young adult population but also occur in adults. Chondrosarcoma and giant cell tumor of bone are generally found in adults. In this review, we describe the current status of our knowledge about treating adults with cancers of bone origin. We also describe our experience treating patients in the adult Sarcoma Medical Oncology group at The University of Texas MD Anderson Cancer Center.

Recurrence Rates and Risk Factors for Primary Giant Cell Tumors around the Knee: A Multicentre Retrospective Study in China

Giant cell tumors of the bone (GCTBs) are commonly diagnosed in Asian populations, usually around the knee. Herein, we aimed to determine the clinical characteristics, local recurrence rates, and relevant risk factors of primary GCTB around the knee. Univariate and multivariate survival analyses were used to identify the risk factors for local recurrence. Four hundred ten patients with primary GCTB around the knee, treated between March 2000 and June 2014, were recruited from 7 institutions in China. The overall local recurrence rate was 23.4%, but was higher in patients aged 20–39 years (28.5%; P = 0.039). The local recurrence rate was the highest in patients treated with intralesional curettage (53.4%), and the lowest in those treated with resection (4.9%). We found a higher risk of tumor recurrence in the proximal fibula compared to the distal femur (hazard ratio: 28.52, 95% confidence interval: 5.88–138.39; P < 0.0001), and in patients treated with curettage compared to those treated with resection (hazard ratio: 12.07, 95% confidence interval: 4.99–29.18; P < 0.0001). Thus, the tumor location must be considered when selecting the optimal surgical treatment approach to reduce the risk of local recurrence and preserve joint function, especially in young patients.

Risks and benefits of combining denosumab and surgery in giant cell tumor of bone-a case series

Background

The RANK ligand inhibitor denosumab is being investigated for treatment of giant cell tumor of bone, but the available data in the literature remains sparse and controversial. This study analyzes the results of combining denosumab with surgical treatment and highlights possible changes for the oncologic surgeon in daily practice.

Methods

A total of 91 patients were treated surgically for giant cell tumor of bone between 2010 and 2014 in an institution, whereas 25 patients of the total additionally received denosumab and were part of this study. The average age of the patients was 35 years. Eleven patients received denosumab pre- and postoperatively, whereas with 14 patients, the denosumab treatment was applied either before (7 patients) or after (7 patients) the surgery. The average preoperative therapy duration was 3.9 months and the postoperative therapy 6 months by default.

Results

Sixteen patients presented a large tumor extension necessitating a resection of the involved bone or joint. In 10 of these patients, the indication for a resection procedure was abandoned due to the preoperative denosumab treatment and a curettage was performed. In the remaining six cases, the surgical indication was not changed despite the denosumab treatment, and two of them needed a joint replacement after the tumor resection. Also with patients treated with curettage, denosumab seems to facilitate the procedure as a new peripheral bone rim around the tumor was built, though a histologic analysis reveals viable tumor cells persisting in the denosumab-induced bone formation.

After an average follow-up of 23 months, one histologically proven local recurrence occurred, necessitating a second curettage. A second patient showed a lesion in the postoperative imaging highly suspicious for local relapse which remained stable under further denosumab treatment. No adverse effect of the denosumab medication was observed in this study.

Conclusions

Denosumab can be a help to the oncologic surgeon by reconstituting a peripheral rim and switching the stage from aggressive to active or latent disease. But as tumor cells remain in the new-formed bone, the surgical technique of curettage has to be changed from gentle to more aggressive to avoid higher local recurrence rates.

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

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

Denosumab treatment of inoperable or locally advanced giant cell tumor of bone

Giant cell tumor of bone (GCTB) is an osteolytic, locally aggressive tumor that rarely metastasizes and typically occurs in the bones. At present, the primary treatment for GCTB is curettage with local adjuvants. Giant cells express receptor activator of nuclear factor-κB ligand (RANKL). Denosumab, a RANKL inhibitor appears to present an effective therapeutic option in advanced cases of GCTB. The aim of the present study was to confirm the efficacy of denosumab in large group of patients with locally advanced GCTB. A total of 35 patients with histologically confirmed GCTB that were treated with denosumab with no participation in clinical trials between May 2013 and September 2015 were included in the present study. Denosumab treatment was administered until complete tumor resection was feasible or tumor progression or unacceptable toxicity had occurred. The mean denosumab treatment duration was 7.4 months. A total of 17 patients received surgery following denosumab treatment: 11 patients underwent wide en bloc resection with prosthesis implantation in 10 cases and 6 patients were treated with intralesional curettage. Tumor progression was observed in 2 patients that underwent intralesional curettage without prosthesis implantation. In addition, tumor progression was observed during denosumab treatment in 2 patients that had previously undergone radiotherapy. The overall 1-year progression-free survival rate was 92.8%. Thus, for patients with advanced, unresectable, progressive or symptomatic pretreated GCTB, denosumab provides a therapeutic option not previously available, which has become the standard therapy in multidisciplinary management of GCTB.

CD10 and CD138 can be expressed in giant cell tumor of bone: An immunohistochemical study

Giant cell tumor of bone (GCTB) is a primary bone neoplasm which is characterized by the presence of mononuclear cells (MCs) and osteoclast-like multinucleated giant cells (MNGCs). Up to our knowledge, CD10 immunoreactivity in GCTB has not yet been studied, and only one study touched on CD138 immunoreactivity in GCTB. The objective of this study is to investigate the immunoreactivity of CD10 and CD138 in GCTB. We offer a discussion of our findings in the context of the differential diagnosis, particularly in small biopsy material. We retrieved and reviewed 15 well-documented cases of GCTB from January 2008 to December 2014. Well-controlled standard immunohistochemical satins were performed on these cases for CD10 and CD138 and few other selected antibodies. Immunoreactivity for CD10 was membranous and was found in 14 (93%) cases. This immunoreactivity was found only in the MCs, whereas the MNGC were all negative. CD138 showed variable positivity in 11 (73%) while 4 (37%) were completely negative. Similar to CD10, staining for CD138 was only seen in the MC; however, the immunoreactivity was predominantly concentrated in the peri-vascular areas. Most of GCTB cases can show variable immunoreactivity for CD10 and CD138. The aforementioned immune-expression raise the possibility of a role in the pathogenesis of GCTB. Paying attention to this immunoreactivity is recommended when considering the clinical and radiological differential diagnosis, especially in small biopsy specimens.

Comparison of tumor curettage and resection for treatment of giant cell tumor of the bone around the knee joint

Objective:

To analyze the efficacies of tumor curettage and resection for treatment of giant cell tumor of the bone (GCTB) around the knee joint (KJ).

Methods:

A total of 126 KJ-GCTB cases were treated at our department from August 2011 to February 2015. These cases were divided into two groups (A and B) according to treatment methods. Group A underwent tumor curettage, while group B underwent tumor resection.

Results:

The relapse rates did not differ significantly between the groups (P>0.05), while the complication rate in group A was significantly lower than that in group B (P<0.05). In addition, the Enneking score for group A was significantly higher than that for group B (P<0.05); in addition, postoperative local recurrence, histopathological grading according to Jaffe, and radiographic imaging-based Campanacci’s staging positively correlated (P<0.05).

Conclusion:

Tumor curettage was the preferred surgical approach for patients with KJ-GCTB.

Sex Differences in the Recurrence Rate and Risk Factors for Primary Giant Cell Tumors Around the Knee in China

Although giant cell tumor of bone (GCTB) is more common in women in Western countries, it tends to be more common in men in Asian countries. We aimed to determine the sex differences in clinical characteristics, local recurrence rate, and relevant risk factors for local recurrence in primary GCTB around the knee. Between March 2000 and June 2014, patients with primary GCTB around the knee were recruited from 7 institutions in China, and 410 patients were included. The age at diagnosis was younger in women than in men (34.0 vs 37.2 years). The local recurrence rates were 23.4% overall, 25.8% in men, and 20.7% in women. Lower local recurrence rates were observed with en-bloc marginal resection in both men (6.9%) and women (3.1%). With tumors located in the distal femur, the local recurrence rate was higher for men than for women (29.1% vs 14.3%, P = 0.025). Local recurrence was significantly associated with the tumor location and surgical operation in men and only surgical operation in women. These findings suggest that more aggressive operations should be considered in men with GCTB in the proximal fibula.