A Translational Study of the Neoplastic Cells of Giant Cell Tumor of Bone Following Neoadjuvant Denosumab

The risk of neurological deterioration while using neoadjuvant denosumab on patients with giant cell tumor of the spine presenting with epidural disease: a meta-analysis of the literature

BACKGROUND CONTEXT

Giant cell tumor (GCT) of bone is most commonly a benign but locally aggressive primary bone tumor. Spinal GCTs account for 2.7% to 6.5% of all GCTs in bone. En bloc resection, which is the preferred treatment for GCT of the spine, may not always be feasible due to the location, extent of the tumor, and/or the patient's comorbidities. Neoadjuvant denosumab has recently been shown to be effective in downstaging GCT, decreasing the size and extent of GCTs. However, the risk of neurologic deterioration is of major concern for patients with epidural spinal cord compression due to spinal GCT. We experienced this concern when a patient presented to our institution with a midthoracic spinal GCT with progressive epidural disease. The patient was not a good surgical candidate due to severe cardiac disease and uncontrolled diabetes. In considering nonoperative management for this patient, we asked ourselves the following question: What is the risk that this patient will develop neurologic deterioration if we do not urgently operate and opt to treat him with denosumab instead?

PURPOSE

The purpose of this study was to assess the literature to (1) determine the risk of neurological deterioration in patients receiving neoadjuvant denosumab for the treatment of spinal GCT and (2) to evaluate the secondary outcomes including radiographic features, surgical/technical complexity, and histological features after treatment.

STUDY DESIGN/SETTING

Meta-analysis of the literature.

PATIENT SAMPLE

Surgical cases of spinal GCT that (1) presented with type III Campanacci lesions, (2) had epidural disease classified as Bilsky type 1B or above and (3) received neoadjuvant denosumab therapy.

OUTCOME MEASURES

The primary outcome measure of interest was neurologic status during denosumab treatment. Secondary outcome measures of interest included radiographic features, surgical/technical complexity, histological features, tumor recurrence, and metastasis.

METHODS

Using predetermined inclusion and exclusion criteria, PubMed and Embase electronic databases were searched in August 2022 for articles reporting spinal GCTs treated with neoadjuvant denosumab and surgery. Keywords used were "Spine" AND "Giant Cell Tumor" AND "Denosumab."

RESULTS

A total of 428 articles were identified and screened. A total of 22 patients from 12 studies were included for review. 17 patients were female (17/22, 77%), mean age was 32 years (18-62 years) and average follow-up was 21 months. Most GCTs occurred in the thoracic and thoracolumbar spine (11 patients, 50%), followed by 36% in the lumbar spine and 14% in the cervical spine. Almost half of the patients had neurological deficits at presentation (10/22 patients, 45%), and more than 60% had Bilsky 2 or 3 epidural spinal cord compression. None of the patients deteriorated neurologically, irrespective of their neurological status at presentation (p-value=.02, CI -2.58 to -0.18). There were no local recurrences reported. One patient was found to have lung nodules postoperatively. More than 90% of cases had decreased overall tumor size and increased bone formation. Surgical dissection was facilitated in more than 85% of those who had documented surgical procedures. Four patients (18%) underwent initial spinal stabilization followed by neoadjuvant denosumab and then surgical excision of the GCT. Regarding the histologic analyses, denosumab eradicated the giant cells in 95% of cases. However, residual Receptor Activator of Nuclear Factor Kappa B Ligand (RANKL)-positive stromal cells were noted, in 27% (6 cases).

CONCLUSIONS

Neoadjuvant denosumab was a safe and effective means of treating spinal GCTs prior to surgery. Neurologic status remained stable or improved in all cases included in our review, irrespective of the presenting neurologic status. The most appropriate dosage and duration of denosumab therapy is yet to be determined. We recommend future well-designed studies to further evaluate the use of neoadjuvant denosumab for patients with spinal GCT.

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

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

Diagnosis and monitoring denosumab therapy of giant cell tumors of bone: radiologic-pathologic correlation

OBJECTIVE

To determine the value of CT and dynamic contrast-enhanced (DCE-)MRI for monitoring denosumab therapy of giant cell tumors of bone (GCTB) by correlating it to histopathology.

MATERIALS AND METHODS

Patients with GCTB under denosumab treatment and monitored with CT and (DCE-)MRI (2012-2021) were retrospectively included. Imaging and (semi-)quantitative measurements were used to assess response/relapse. Tissue samples were analyzed using computerized segmentation for vascularization and number of neoplastic and giant cells. Pearson's correlation/Spearman's rank coefficient and Kruskal-Wallis tests were used to assess correlations between histopathology and radiology.

RESULTS

Six patients (28 ± 8years; five men) were evaluated. On CT, good responders showed progressive re-ossification (+7.8HU/month) and cortical remodeling (woven bone). MRI showed an SI decrease relative to muscle on T1-weighted (-0.01 A.U./month) and on fat-saturated T2-weighted sequences (-0.03 A.U./month). Time-intensity-curves evolved from a type IV with high first pass, high amplitude, and steep wash-out to a slow type II. An increase in time-to-peak (+100%) and a decrease in Ktrans (-71%) were observed. This is consistent with microscopic examination, showing a decrease of giant cells (-76%), neoplastic cells (-63%), and blood vessels (-28%). There was a strong statistical significant inverse correlation between time-to-peak and microvessel density (ρ = -0.9, p = 0.01). Significantly less neoplastic (p = 0.03) and giant cells (p = 0.04) were found with a time-intensity curve type II, compared to a type IV. Two patients showed relapse after initial good response when stopping denosumab. Inverse imaging and pathological findings were observed.

CONCLUSION

CT and (DCE-)MRI show a good correlation with pathology and allow adequate evaluation of response to denosumab and detection of therapy failure.

Non‑surgical outcomes and risk factors for pulmonary metastasis from giant cell tumor of bone

The present study detailed four factors associated with an increased risk of pulmonary metastasis, age, pathological fracture, local recurrence and mode of treatment. Local recurrence and pathological fracture were independent risk factors for developing metastasis. From January 2016 to December 2021, data from 50 patients diagnosed with giant cell tumor of bone (GCTB) treated in Khon Kaen Hospital, Thailand, were retrospectively analyzed. The risk factors, including age at diagnosis, location of GCTB, clinical presentation, Campanacci stage and no. of local recurrences, for GCTB-induced pulmonary metastasis were evaluated using univariate and multivariable logistic regression analyses. Of the 50 patients analyzed, 9 patients (18%), with a mean age of 46.3 years (range, 18-68 years), developed pulmonary metastasis. No patients died from pulmonary metastasis in the present study. Statistically significant associations were observed between the development of metastasis and both clinical fracture [odds ratio (OR), 6.107; 95% confidence interval (CI), 1.08-34.70] and local recurrence (OR, 6.48; 95% CI, 1.03-40.87). Patients presenting with both a clinical fracture and local tumor recurrence require more rigorous clinical observation due to the significantly elevated risk of disease progression.

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

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

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

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

Approach to the Treatment of Expansile Metacarpal Aneurysmal Bone Cysts: A Report of Two Cases

The two cases presented demonstrate the management of aneurysmal bone cysts of the metacarpal, which destroyed the normal bone architecture. Treatment of both cases included wide resection and metacarpal reconstruction with an intercalary fibular allograft. Denosumab use contrasts these two cases and is helpful in reestablishment of a cortical rim for fixation in the absence of a 1-cm margin proximally or distally to preserve the native carpometacarpal and metacarpophalangeal joints. Surgical resection and allograft reconstruction is a viable treatment for expansile metacarpal aneurysmal bone cysts, and neoadjuvant denosumab has utility in creating an ossified margin for fixation.

Current therapies and future prospective for locally aggressive mesenchymal tumors

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

Association between Inflammatory Markers and Local Recurrence in Patients with Giant Cell Tumor of Bone: A Preliminary Result

Giant cell tumor of bone (GCTB) has a high local recurrence rate of approximately 20%. Systemic inflammatory markers, such as neutrophil-lymphocyte ratio (NLR), modified Glasgow prognostic score (mGPS), prognostic nutritional index (PNI), lymphocyte-monocyte ratio (LMR), platelet-lymphocyte ratio (PLR), hemoglobin (Hb), alkaline phosphatase (ALP), and lactate dehydrogenase (LDH), have been reported as prognostic markers in patients with malignant tumors. This study aimed to investigate the correlation between these markers and the local recurrence rate of GCTB. In total, 103 patients with GCTB who underwent surgery at the authors' institutions between 1993 and 2021 were included. Thirty patients experienced local recurrence. Univariate and multivariate analysis showed that tumor site, preoperative and postoperative denosumab treatment, and surgery were significantly associated with local recurrence-free survival. LDH was associated with local recurrence-free survival on univariate analysis only. NLR, mGPS, PNI, LMR, and PLR score did not correlate with the local recurrence rate. In conclusion, NLR, mGPS, PNI, LMR, PLR score, Hb, ALP, and LDH levels are not correlated with the local recurrence rate of GCTB. However, due to the small number of patients included in this study, this result should be re-evaluated in a multicenter study with a larger sample size.

Outcome of re-operation for local recurrence following pre-operative denosumab administration and curettage for giant cell tumour of bone with difficult joint preservation

PURPOSE

Denosumab enables joint-sparing surgery (curettage) and surgical downstaging in patients with giant cell tumour of bone (GCTB), where joint preservation is not possible. However, denosumab treatment causes osteosclerosis of the lesion, making it difficult to curet the lesion, leaving the tumour behind, and increasing the local recurrence rate. We performed a three-centre retrospective study to investigate the postoperative local re-recurrence rate, joint preservation status, and functional outcomes of locally recurrent lesions after preoperative denosumab treatment and curettage in patients with difficult joint preservation.

METHODS

We included 38 of 142 patients with primary GCTB of the extremities who underwent preoperative denosumab and curettage between 2009 and 2021 with local recurrence. Preoperative denosumab was indicated in patients with minimal residual periarticular and subchondral bones, large extraosseous lesions (Campanacci stage 3), and pathological fractures that made joint preservation difficult.

RESULTS

Local re-recurrence occurred in 6 (15.8%) of the 38 patients. In 29 patients who underwent re-curettage, local re-recurrence occurred in six patients (20.7%); however, in nine patients who underwent en bloc resection, no local re-recurrence was observed. The joint preservation rate was 63.2% (24 of 38 patients), with a median Musculoskeletal Tumor Society score of 28 (interquartile range: 26.8-29.0). The median follow-up period after surgery for local recurrence was 63.5 months (interquartile range: 42.5-82.4).

CONCLUSION

Since the local re-recurrence rate after re-curettage for local recurrence was low, and the joint preservation rate and affected limb function were good, preoperative denosumab administration may be considered in patients who require downstaging to maintain good limb function (joint preservation).

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

Aims

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

Methods

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

Results

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

Conclusion

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

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

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

Comprehensive treatment outcomes of giant cell tumor of the spine: A retrospective study

There is no consensus on a treatment strategy for spinal giant cell tumor of bone (GCTB) because of the difficulty in their treatment. Treatment options often include the use of the controversial denosumab, an antibody therapy aimed at tumor shrinkage, different curettage techniques, resection, or a combination of these therapies. The current study aimed to identify treatment methods associated with favorable outcomes in patients with spinal GCTB. We retrospectively reviewed 5 patients with spinal GCTB, including patients with tumors of the sacrum, treated at our hospital between September 2011 and November 2020. Two men and 3 women were included in the study. The median follow-up period was 74 months (range: 14-108 months). We surveyed the tumor site, treatment method, denosumab use, and outcomes. The median age was 17 years (range: 17-42 years). There were 2 cases of sacral GCTB and 1 case each of lumbar, cervical, and thoracic vertebral GCTB. The comorbidities observed included hepatitis, malignant lymphoma, atopic dermatitis, and asthma. The treatment method included zoledronic acid after embolization and denosumab, denosumab only, curettage and posterior fusion, and curettage resection after embolization and anterior and posterior fusion. Denosumab was used in all cases. Three patients were continuously disease-free, 1 patient with no evidence of disease, and 1 patient alive with disease. Aggressive treatment, especially surgical treatment, may lead to good results in spinal GCTB.

Nuclear β-catenin translocation plays a key role in osteoblast differentiation of giant cell tumor of bone

Denosumab is a game-changing drug for giant cell tumor of bone (GCTB); however, its clinical biomarker regarding tumor ossification of GCTB has not been elucidated. In this study, we investigated the relationship between Wnt/β-catenin signaling and the ossification of GCTB and evaluated whether endogenous nuclear β-catenin expression predicted denosumab-induced bone formation in GCTB. Genuine patient-derived primary GCTB tumor stromal cells exhibited osteoblastic characteristics. Identified osteoblastic markers and nuclear β-catenin translocation were significantly upregulated via differentiation induction and were inhibited by treating with Wnt signaling inhibitor, GGTI-286, or selective Rac1-LEF inhibitor, NSC23766. Furthermore, we reviewed the endogenous ossification and nuclear β-catenin translocation of 86 GCTB clinical samples and elucidated that intra-tumoral ossification was significantly associated with the nuclear translocation. Three-dimensional quantitative analyses (n = 13) of tumoral CT images have revealed that the nuclear β-catenin translocation of naïve GCTB samples was significantly involved with the denosumab-induced tumor ossification. Our findings suggest a close relationship between the nuclear β-catenin translocation and the osteoblastic differentiation of GCTB. Investigations of the nuclear β-catenin in naïve GCTB samples may provide a promising biomarker for predicting the ossification of GCTB following denosumab treatment.

Updated concepts in treatment of giant cell tumor of bone

PURPOSE OF REVIEW

Giant cell tumors of bone (GCTB) are intermediate, locally aggressive primary bone tumors. For conventional GCTB, surgery remains treatment of choice. For advanced GCTB, a more important role came into play for systemic therapy including denosumab and bisphosphonates over the last decade.

RECENT FINDINGS

In diagnostics, focus has been on H3F3A (G34) driver mutations present in GCTB. The most frequent mutation (G34W) can be detected using immunohistochemistry and is highly specific in differentiating GCTB from other giant cell containing tumors. PD-L1 expression can be used as biological marker to predict higher recurrence risks in GCTB patients.The use of bisphosphonate-loaded bone cement is under investigation in a randomized controlled trial. A new technique consisting of percutaneous microwave ablation and bisphosphonate-loaded polymethylmethacrylate cementoplasty was proposed for unresectable (pelvic) GCTB.Increased experience with use of denosumab raised concern on elevated recurrence rates. However, conclusions of meta-analyses should be interpreted with risk of indication bias in mind. Several small studies are published with short-course denosumab (varying from 3 to 6 doses). One small trial directly compared denosumab and zoledronic acid, with no statistical differences in radiological and clinical outcome, and nonsignificantly higher recurrence rate after denosumab. As bisphosphonates directly target neoplastic stromal cells in GCTB, larger directly comparative trials are still warranted.

SUMMARY

Neoadjuvant denosumab is highly effective for advanced GCTB, and a short-course is advised to facilitate surgery, whereas increased recurrence rates remain of concern. Randomized controlled trials are conducted on bisphosphonate-loaded bone cement and on optimal dose and duration of neoadjuvant denosumab. PD-L1 could be a potential new therapy target in GCTB.

En Bloc Resection of Giant Cell Tumor following Neoadjuvant Denosumab: A Case Report and Review of the Literature

Introduction

The RANK ligand inhibitor denosumab has been used to treat cases of unresectable giant cell tumors of bone (GCTB) or preoperatively to facilitate intralesional curettage. However, there are no clear guidelines for use of denosumab prior to en bloc resection.

Case Presentation

In this study, a 26-year-old patient presented with atraumatic lateral knee pain. X-rays demonstrated a destructive lesion within the proximal fibula, and biopsy confirmed the diagnosis of GCTB.

Management and Outcomes

The patient received 3 months of neoadjuvant denosumab with complete resolution of his pain and cortical rim formation surrounding the tumor. The tumor was removed en bloc with negative margins. At 6-month follow-up, the patient had returned to his functional baseline with no evidence of tumor recurrence.

Conclusion

Neoadjuvant denosumab can mitigate symptoms related to GCTB and promotes cortical bone formation, facilitating en bloc resection and permitting acceptable functional outcomes in select cases.

Ultra-Short Course of Neo-Adjuvant Denosumab for Nerve-Sparing Surgery for Giant Cell Tumor of Bone in Sacrum

STUDY DEIGN

This was a retrospective study about sacral giant cell tumor of bone (GCTB).

OBJECTIVE

This study aimed to investigate whether ultra-short course of neo-adjuvant denosumab treatment for sacral GCTB could (1) induce radiological and histological response? (2) Facilitate nerve-sparing surgery? (3) Achieve satisfactory oncological and functional outcomes?

SUMMARY OF BACKGROUND DATA

Previous reports on long course of neo-adjuvant denosumab treatment for GCTB showed significant tumor response and a relatively high recurrent rate after curettage.

METHODS

Sixty-six patients with sacral GCTB treated with neoadjuvant denosumab and nerve-sparing surgery were categorized into ultra-short course group (≤3 doses and operation within D21 since 1st dose, 41 patients) or conventional group (>3 doses or operation after D21 since 1st dose, 25 patients). The radiological and histological response, operative data, oncological and functional outcomes were compared.

RESULTS

The ultra-short course group demonstrated fewer doses of neo-adjuvant denosumab (mean: 2.1 vs. 4.8, P  < 0.001) and shorter time to surgery (12.2 days vs. 72.3 days, P < 0.001). Similar patterns of radiological and histological response were observed in the two groups with less fibrosis and ossification in the ultra-short course group. The operative duration (199.9 min vs. 187.8 min, P = 0.364) and estimated blood loss (1552.4 mL vs. 1474.0 mL, P = 0.740) were comparable. Most (94.8%) of the patients received adjuvant denosumab. After a mean follow-up of 29.4 months, three cases (8.8%) and five cases (20.8%) showed local recurrence in each group (P = 0.255). The estimated recurrence-free survival (56.2 vs. 51.2 months, P = 0.210) and the functional status [Motor-Urination-Defecation scores: 25.9 vs. 25.7, P = 0.762] did not differ between the two groups.

CONCLUSION

Ultra-short course of neo-adjuvant denosumab for sacral GCTB could elicit radiological and histological responses as conventional course did. The less degree of fibrosis and ossification might facilitate nerve-sparing surgery and help to achieve satisfactory local control and functional status.Level of Evidence: 4.

A randomized phase III trial of denosumab before curettage for giant cell tumor of bone. JCOG1610

OBJECTIVES

The aim of JCOG1610 (randomized controlled phase III trial) was to confirm the superiority of preoperative denosumab to curettage with adjuvant local therapy for patients with giant cell tumor of bone without possible post-operative large bone defect.

METHODS

The primary endpoint was relapse-free survival and the total sample size was set at 106 patients. Patient accrual began in October 2017. However, the accrual was terminated in December 2020 due to a recommendation from the Data and Safety Monitoring Committee because of poor patient accrual. Now, we report the descriptive results obtained in this study.

RESULTS

A total of 18 patients had been registered from 13 Japanese institutions at the time of termination on December 2020. Eleven patients were assigned to Arm A (curettage and adjuvant local therapy) and 7 to Arm B (preoperative denosumab, curettage and adjuvant local therapy). Median follow-up period was 1.6 (range: 0.5-2.8) years. Protocol treatment was completed in all but one patient in Arm A who had a pathological fracture before surgery. All patients in Arm B were treated with five courses of preoperative denosumab. Relapse-free survival proportions in Arm A and B were 90.0% (95% confidence interval: 47.3-98.5) and 100% (100-100) at 1 year, and 60.0% (19.0-85.5) and 62.5% (14.2-89.3) at 2 years, respectively [hazard ratio (95% confidence interval): 1.51 (0.24-9.41)].

CONCLUSION

In terms of relapse-free survival, the superiority of preoperative denosumab was not observed in patients with giant cell tumor of bone without possible post-operative large bone defect.

Sclerostin immunohistochemical staining in surgically treated giant cell tumor of bone

BACKGROUND

Giant cell tumor of bone (GCTB) is a destructive lesion with a high potential for recurrence. RANK-ligand targeted therapy has provided promising, yet mixed results. Sclerostin (SOST) inhibition results in a net anabolic response and is currently used in the treatment of osteoporosis. The application to GCTB is unknown.

OBJECTIVES

We sought to determine if GCTB stained for SOST on immunohistochemistry and correlate its expression with predictor variables.

METHODS

All patients at a single institution undergoing surgery for GCTB between 1993 and 2008 with a minimum of 6 months follow-up were included. Primary outcomes included the presence of SOST staining, secondary outcomes included the correlation of patient and tumor-specific predictor variables.

RESULTS

SOST antibody staining of any cell type was present in 47 of 48 cases (97.9%). Positivity of the stromal cells was present in 39 of 48 cases (81.3%) and was associated with radiographic aggressiveness (p = 0.023), symptomatic presentation (p = 0.032), prior surgery (p = 0.005), and patient age (p = 0.034). Positivity of giant cells was present in 41 of 48 cases (85.4%) and was not significant with predictive factors.

CONCLUSIONS

Sclerostin staining in GCTB is a novel finding and warrants further research to define the role of sclerostin as a prognostic factor and therapeutic target.

Aneurysmal bone cyst and osteoblastoma after neoadjuvant denosumab: histologic spectrum and potential diagnostic pitfalls

The use of denosumab to treat giant cell tumors of bone (GCT) and other giant cell-containing bone tumors has become more common. While the clinicopathologic features of denosumab-treated giant cell tumors of bone have been well-illustrated, descriptions of other denosumab-treated bone tumors are very limited. Surgical pathology files of two institutions and consultation files from two authors were searched for denosumab-treated aneurysmal bone cysts and denosumab-treated osteoblastomas. Clinicopathologic features were reviewed and analyzed. We identified four patients with denosumab-treated bone tumors other than GCT from our surgical pathology and consultation files, including two aneurysmal bone cysts and two osteoblastomas. All were treated with denosumab for 0.5-7.0 (median 4.5) months. Radiologically, denosumab-treated tumors showed decreased size with increased ossification and mineralization on CT and heterogeneous intermediate to hypointense signal on MRI. Histologically, denosumab-treated aneurysmal bone cyst contained thin, elongated, curvilinear, and anastomosing strands of bone with empty lacunae, while denosumab-treated osteoblastoma showed circumscribed nodules of woven bone lined by small osteoblasts. Denosumab-treated aneurysmal bone cyst and osteoblastoma showed treatment-related morphologic changes that can mimic other bone neoplasms. Their recognition requires correlation with the clinical history of denosumab use and radiologic findings.

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.

Preoperative Denosumab Therapy Against Giant Cell Tumor of Bone is Associated with an Increased Risk of Local Recurrence After Curettage Surgery

INTRODUCTION

Denosumab has been shown to be highly effective at suppressing the progression of giant cell tumor of bone (GCTB). However, recent studies have observed a potential increased risk of local recurrence after surgery following the use of denosumab, raising concerns on the use of this agent against GCTB in combination with surgery.

METHODS

We retrospectively reviewed the medical records of 234 patients with GCTB who were surgically treated at multiple institutions from 1990 to 2017. Patient background, tumor characteristics, treatment methods, local recurrence-free survival rate, distant metastasis rate, oncologic outcome, and limb function at final follow-up were analyzed and compared between cases treated with and without denosumab.

RESULTS

The 3-year local recurrence-free survival rate was significantly lower in patients who underwent preoperative denosumab therapy (35.3%) compared with those treated without denosumab (79.9%) (P < 0.001). Among patients who were preoperatively treated with denosumab, those who had a local recurrence all underwent curettage surgery.

CONCLUSIONS

Preoperative denosumab therapy in combination with curettage surgery was significantly associated with an increased risk of local recurrence in Campanacci grade 3 tumors. Our data suggest that clinicians seeing GCTB patients should be aware to this increased risk when planning preoperative denosumab therapy.

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

Simple Summary

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

Abstract

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

Sclerostin Immunohistochemical Staining in Aggressive Maxillofacial Giant Cell Lesions: Initial Results and Potential Therapeutic Target

INTRODUCTION

Maxillofacial (MF) giant cell lesions (GCLs) are benign, often locally aggressive lesions with potential for recurrence. Systemic treatments have included interferon alpha, calcitonin, bisphosphonates, and denosumab. Sclerostin (SOST) is typically thought to be a negative regulator of bone metabolism and anti-SOST agents have been used to treat osteoporosis; however, its role in central giant cell granuloma is unknown. The purpose of this study was to evaluate the expression of SOST in MF GCLs.

MATERIALS AND METHODS

This was a retrospective study of patients with MF GCLs treated at a single institution between 1993 and 2008 with a minimum follow-up of 6 months. Representative tissue was used to create a tissue microarray and SOST immunohistochemical (IHC) staining and grading was performed. The primary outcomes were IHC staining of the stromal cells and giant cells. The secondary outcomes included correlation of IHC staining and patient predictor variables including clinically benign and aggressive lesions. All analyses were completed using univariate statistical tests.

RESULTS

A total of 37 subjects were included (29 clinically aggressive and 8 clinically benign). Sclerostin staining was present in 30 of 37 subjects (81%). Of these, 22 (60%) had stromal cell staining and 28 (76%) had giant cell staining. The presence or absence of staining, of either cell type, was not associated with aggressiveness, presence of clinical symptoms, tumor size, previous interferon therapy, previous surgery, or the race or age of the patient.

DISCUSSION

Maxillofacial GCLs have an overall high level of SOST staining; however, the role of SOST in treatment and prognosis is unknown and warrants further study.

Giant cell tumour of hand bones: outcomes of treatment

The purpose of this study was to report the incidence of giant cell tumour of the hand bones in an Asian population, document treatment options and report outcomes of treatment. Of 698 giant cell tumours of bone that underwent surgery between January 2011 and December 2020 at our institute, only 22 (3%) were in the hand. Fourteen occurred in the metacarpals, eight in the phalanges. Fifteen were primary tumours and seven had recurrent disease. Twenty lesions had an associated soft tissue component. Two patients treated for primary disease and one who had been treated for recurrence had local recurrence. Recurrence occurred in two of nine patients treated with curettage, one of three with resection and none of five with ray or digit amputation. Both curettage and resection/amputation are acceptable treatment options for the rare condition of giant cell tumour of bone in the hand, with a need to individualize treatment decisions based on the site and extent of disease to minimize treatment morbidity while maximizing disease control.Level of evidence: IV.

What's new in musculoskeletal oncology

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

Current Concepts in the Treatment of Giant Cell Tumors of Bone

Simple Summary

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

Abstract

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

Rechallenge of denosumab in jaw osteonecrosis of patients with unresectable giant cell tumour of bone: a case series analysis and literature review

Objectives

Giant cell tumour of bone (GCTB) is a rare tumour, generally managed with surgery. Treatment of the very rare unresectable advanced/metastatic GCTB is challenging and denosumab is the only current available medical option, an anti-RANKL monoclonal antibody inhibiting osteolysis. An uncommon but severe and treatment-limiting adverse event of denosumab is the osteonecrosis of the jaw (ONJ). The clinical management of GCTB patients stopping denosumab for medication-related (MR)-ONJ and the possible reintroduction of denosumab after MR-ONJ resolution is matter of debate. We performed a retrospective study to describe the incidence, clinical features and outcome of MR-ONJ in unresectable GCTB patients treated with denosumab at our Institution.

Design and setting

Retrospective, single-institutional study.

Participants

Adult patients receiving denosumab as antineoplastic therapy for GCTB and experiencing MR-ONJ at Fondazione IRCCS Istituto Nazionale Tumori of Milan between January 2008 and July 2019.

Main outcome measures

Incidence, time of onset and clinical features of MR-ONJ.

Results

29 patients with locally advanced and/or metastatic GCTB treated with denosumab were identified. At a median follow-up of 70 months (range 1–125), 4 (13.8%) patients experienced MR-ONJ while on treatment, after 125, 119, 85 and 41 months of denosumab, respectively. All patients showed an ongoing tumour stabilisation with denosumab at the MR-ONJ onset and in all cases denosumab was stopped. All four patients were treated with ozone therapy. Two are waiting for surgery, two were already operated on. Both of them experienced disease progression and were thus rechallenged with denosumab. One is still on therapy after 25 months. The other had an MR-ONJ relapse after 39 months and was treated again with ozone therapy and surgery. She is under surveillance, GCTB being currently stable.

Conclusion

A clinical algorithm of denosumab rechallenge after complete resolution of MR-ONJ in progressing GCTB patients should be prospectively validated.

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.

Risk factors and oncological outcomes of pulmonary metastasis in patients with giant cell tumor of bone

BACKGROUND

Giant cell tumor (GCT) of bone has a rare potential for metastatic spread. This study aimed at evaluating the incidence of chest metastases in GCT and their oncological outcome and identifying possible risk factors.

METHODS

Medical records of 466 (313 de novo and 153 recurrent) patients with primary GCT of bone were retrospectively reviewed. Fifteen (3.2%) patients developed chest metastasis. Time from diagnosis of the primary bone lesion to the diagnosis of metastasis, treatment modalities of metastasis, and the course of treatment were revised. The functional outcome was evaluated using the Musculoskeletal Tumor Society (MSTS) scoring system, and postoperative complications were recorded.

RESULTS

This study included 7 males and 8 females with a mean age of 27.3 ± 7.9 years. The most common site of the primary tumor was the distal femur. All fifteen patients were recurrent cases. The mean follow-up period was 67.7 ± 33.2 months. Chest metastasis was diagnosed after a mean time of 28.1 ± 28.9 months from the initial diagnosis of the bone lesion. One patient died of disease (DOD) 18 months after the surgical intervention. The incidence of chest metastasis in recurrent cases was 9.8%, while de novo cases did not develop chest metastasis, P < 0.001. Previous curettage was associated with a higher incidence of chest metastasis (14.6%) compared to previous resection (4.2%), P = 0.03.

CONCLUSIONS

Chest metastasis following GCT of bone is rare. Risk factors include recurrent cases, especially following previous curettage. Patients have a good prognosis and a low mortality rate.

LEVEL OF EVIDENCE

Level IV, retrospective.

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.

Profiling of three H3F3A-mutated and denosumab-treated giant cell tumors of bone points to diverging pathways during progression and malignant transformation

Giant cell tumor of bone (GCTB) is a locally aggressive lesion of intermediate malignancy. Malignant transformation of GCTB is a rare event. In 2013, the humanized monoclonal antibody against receptor activator of nuclear factor-κb-Ligand (RANKL) denosumab was approved for treatment of advanced GCTB. Since then, several reports have questioned the role of denosumab during occasional malignant transformation of GCTB. We report on three patients with H3F3A-mutated GCTBs, treated with denosumab. The tissue samples were analysed by histomorphology, immunohistochemistry, and in two instances by next generation panel sequencing of samples before and after treatment. One patient had a mutation of ARID2 in the recurrence of the GCTB under treatment with denosumab. One patient developed a pleomorphic sarcoma and one an osteoblastic osteosarcoma during treatment. Sequencing revealed a persisting H3F3A mutation in the osteosarcoma while the pleomorphic sarcoma lost the H3F3A mutation; however, a FGFR1 mutation, both in the recurrence and in the pleomorphic sarcoma persisted. In addition, the pleomorphic sarcoma showed an AKT2 and a NRAS mutation. These data are inconclusive concerning the role denosumab plays in the event of malignant progression/transformation of GCTB and point to diverging pathways of tumor progression of GCTB associated with this treatment.

Immunohistochemical Characterization of Giant Cell Tumor of Bone Treated With Denosumab: Support for Osteoblastic Differentiation

Giant cell tumor of bone is a locally aggressive, rarely metastasizing neoplasm. Evidence suggests that the neoplastic cells may be osteoblastic in differentiation. Standard treatment is surgical removal, but medical therapy with denosumab, an inhibitor of receptor activator of nuclear factor-κβ ligand, has become a component of patient management in select cases. Denosumab-treated giant cell tumor of bone (DT-GCTB) shows drastic morphologic changes including the presence of abundant bone. To further determine the relationship of the neoplastic cells to osteoblast phenotype, we performed a morphologic and immunohistochemical study on a series of DT-GCTB. Cases of DT-GCTB were retrieved from surgical pathology files, available slides were reviewed, and immunohistochemistry for H3.3 G34W, SATB2, and p63 was performed. The cohort included 31 tumors from 30 patients (2:3 male:female), ages 15 to 73 years (median=36 y). The morphology of post-denosumab-treated tumors ranged from tumors composed of an abundant bone matrix with few spindle cells to spindle cell-predominant tumors. Five had focal residual classic CGTB, and 2 manifested mild nuclear atypia. The majority expressed all markers: 86.2% for H3.3 G34W, 96.7% for SATB2, and 100% for p63. All markers stained the various tumor components including spindle cells and the cells on the surface of and within the treated tumor bone matrix. Most markers were also positive in reactive-appearing woven bone adjacent to tumor: 84.6% for H3.3 G34W, 100% for SATB2, and 68% for p63. These findings suggest that denosumab treatment of giant cell tumor of bone results in osteoblastic differentiation with bone production.

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.

Preoperative Denosumab may increase the Risk of Local Recurrence of Giant-cell Tumor of Bone Treated with Curettage: A Systematic Review and Meta-analysis

Objective: This systematic review and meta-analysis aimed to determine the effect of preoperative denosumab on the local recurrence of giant-cell tumor of bone (GCTB) treated with curettage. Methods: PubMed, Embase, Cochrane Library, and Web of Science were comprehensively searched. The following data were analyzed using meta-analysis: local recurrence rate of patients receiving denosumab followed by curettage (denosumab group), local recurrence rate of patients receiving curettage only (control group), and a comparison of the local recurrence rates of the two groups. Results: Nine studies that contained 672 patients with GCTB were included in this review. Patients in the denosumab group (preoperative denosumab followed by curettage) had a higher risk of local recurrence compared with those in the control group (curettage only) (odds ratio = 3.04, 95% confidence interval = 1.48-6.22, P < 0.01). The association between preoperative denosumab and local recurrence remained significant in most of the subgroup analyses, except for those with sample sizes < 59 (P = 0.09), sacral GCTB (P = 0.42), and usage of postoperative denosumab (P = 0.38). Conclusions: Preoperative denosumab may increase the risk of local recurrence of GCTB treated with curettage and should be used with caution in the management of GCTB.

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.

Giant cell tumors of the sacrum: is non-operative treatment effective?

PURPOSE

Giant cell tumors of sacrum in which surgery could endanger important neural components were treated with short term denosumab, angioembolisation and radiotherapy in different combinations to provide a non-operative function preserving treatment option.

METHODS

Between April 2013 and April 2017, 13 sacral GCTs [proximal extent of disease-S1 (10), S2 (2) and S3 (1)] were treated. Age ranged from 20 to 50 years. One patient had loss of bladder control at presentation. Treatment protocol included short term denosumab, angioembolisation and radiotherapy in different combinations. Patients were evaluated every 10-12 weeks. If disease ceased to progress no further treatment was advised. In case of progress, patient was advised additional denosumab and/or angioembolisation and/or radiotherapy till disease stopped progressing.

RESULTS

10 patients have non-progressive disease and are asymptomatic, 2 have non-progressive disease with occasional pain, 1 patient died. Follow-up duration (since final non-progression of disease) ranged from 15 to 54 months (mean 31 months). Total number of angio embolisation sessions ranged from 0 to 12 (mean = 4), total number of denosumab doses ranged from 5 to 16 (mean = 9). Five patients did not receive any radiotherapy, 5 received 50.4 Gy and one patient each received 50.4 + 30 + 12 Gy, 50.4 + 30 Gy and 50.4 + 12 Gy. The patient with loss of bladder control at presentation recovered. There were no other long-term complications.

CONCLUSION

This study offers a non-surgical management option that provides good mid-term local control while preserving neurological function in these complex lesions.

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.

Overview of the management of primary tumors of the spine

STUDY DESIGN

Narrative review.

OBJECTIVE

To provide a narrative review for diagnosis and management of Primary spine tumors.

METHODS

A detailed review of literature was done to identify relevant and well cited manuscripts to construct this narrative review.

RESULTS

Primary tumors of the spine are rare with some racial differences reported. There are numerous adjuvant technologies and developments that influence the way we currently manage these tumors. Collimated radiation allows for heavy dosage to be delivered and have been reported to give good local control both as an adjuvant and neoadjuvant setting. These have made surgical decision making even more intricate needing a multicentric approach. Dedicated care has been shown to significantly improve health quality of life measures and survival.

CONCLUSION

While, it is beyond the scope of this paper to discuss all primary tumors subtypes individually, this review highlights the developments and approach to primary spine tumors.

Denosumab for Bone Giant Cell Tumor of the Distal Radius

There are conflicting reports regarding the outcome and effect of denosumab for distal radius giant cell tumor of bone (GCTB). The authors performed this study to evaluate the behavior of distal radius GCTB in relation to the type of treatment and the administration of denosumab. The files of 72 patients with distal radius GCTB treated from 1984 to 2018 were reviewed. Fourteen patients were administered denosumab. Surgical treatment consisted of curettage (25 patients) or resection (47 patients) and allograft or vascularized fibular head graft reconstruction. Median follow-up was 63.1 months (interquartile range [IQR], 35.5-107.1 months). The authors evaluated local recurrences, metastasis, function, and complications. The local recurrence rate was 30.6% at a median of 14.0 months (IQR, 10-19 months), with no difference between curettage and resection. The local recurrence rate was significantly higher in the patients who received denosumab. The metastasis rate was 9.7% at a median of 41.0 months (IQR, 15-114 months), with no difference regarding denosumab administration. Function was significantly better in patients after curettage. The complication rate was 25%; vascularized fibular graft reconstruction was associated with fewer complications. This study found that denosumab increases the risk of local recurrence after curettage, function is better after curettage, and vascularized fibular graft is the optimal reconstruction after resection of distal radius GCTB. [Orthopedics. 2020;43(5):284-291.].

Vascularized Ulnar Transposition and Radioulnoscapholunate Fusion With Volar Locking Plate in a Dorsal Position Following Resection of Giant Cell Tumor of the Distal Radius

Giant cell tumor of the distal radius is a rare, locally destructive, and frequently recurrent tumor. We present a case of Campanacci Grade III giant cell tumor of the distal radius with pathologic fracture and cortical destruction which was treated with neoadjuvant denosumab. This facilitated en-bloc resection of the entire distal radius, including the articular surface, while minimizing tumor contamination. Reconstruction was accomplished using a vascularized ulnar transposition flap to facilitate radioulnoscapholunate fusion, which was fixated using a long-stem contralateral variable angle locking volar distal radius plate in a dorsal position. This case illustrates multidisciplinary management of a challenging reconstructive problem and demonstrates a novel strategy for fixation which repurposes familiar and readily available hardware to provide optimal osteosynthesis.

Incidence, Management, and Outcomes of Spinal Giant Cell Tumor of Bone in Adult Patients: A National Cancer Database Analysis

OBJECTIVE

Giant cell tumors (GCTs) constitute 5% of all primary bone tumors with spinal GCTs (SGCTs) accounting for 2%-15% of all GCTs. The standard of care for SGCT has been maximal surgical resection. However, many adjuvant therapies have been used owing to the difficulty in achieving gross total resection combined with the high local recurrence rate. The purpose of the present study was to analyze the incidence, management, and outcomes of SGCT.

METHODS

Patients with diagnosis codes specific for SGCT were queried from the National Cancer Database from 2004 to 2016. The outcomes were investigated using Cox univariate and multivariate regression analyses, and survival curves were generated for comparative visualization.

RESULTS

The search criteria identified 92 patients in the NCDB dataset from 2004 to 2016 with a diagnosis of SGCT. Of the 92 patients, 64.1% had undergone surgical intervention, 24.8% had received radiotherapy, and 15.2% had received immunotherapy. Univariate analysis revealed that age ≥55 years and tumor location in the sacrum/coccyx were associated with worsened overall survival (OS) and that surgical resection was associated with improved OS. On multivariate analysis, age 55-64 years was associated with worsened OS, and radical surgical resection was associated with improved OS. The survival analysis revealed improved OS with surgery but not with radiotherapy, chemotherapy, or immunotherapy.

CONCLUSION

SGCT is a rare primary bone tumor of the vertebral column. The standard of care has been surgical resection with the goal of gross total resection; however, adjuvant therapies have often been used. Our study found that surgical resection significantly improved OS and that immunotherapy neared significance in improving OS.

Giant Cell Tumors of the Upper Extremity: Predictors of Recurrence

PURPOSE

Giant cell tumors (GCT) of the distal radius are thought to be more aggressive than in other locations. Therefore, the aim of this study was to investigate factors associated with recurrence of GCTs in the upper extremity.

METHODS

We retrospectively identified 82 patients who underwent primary surgical treatment for an upper extremity GCT. Tumors were located in the radius (n = 47), humerus (n = 17), ulna (n = 9), and hand (n = 9). Treatment consisted of either wide resection or amputation or intralesional resection with or without adjuvants. A multivariable logistic regression was performed including tumor grade, type of surgery, and tumor location, from which the percentage of contribution to the model of each variable was calculated.

RESULTS

The recurrence rate after intralesional resection was 48%; after wide resection or amputation, it was 12%. Two patients developed a pulmonary metastasis (2.4%). In multivariable analysis, intralesional resection was independently associated with recurrence. Intralesional resection had a 77% contribution to predict recurrence and the distal radius location had a 16% contribution in the predictive model.

CONCLUSIONS

As expected, intralesional resection was the strongest independent predictor of recurrence after surgical treatment for GCT. The distal radius location contributed to the prediction of giant cell tumor recurrence to a lesser extent.

TYPE OF STUDY/LEVEL OF EVIDENCE

Prognostic IV.

Histomorphometric Analysis of Pre- and Post-Denosumab-Treated Giant Cell Tumor of Bone

Context. Denosumab is a monoclonal antibody against RANK ligand. Its administration in giant cell tumor of bone (GCTB) cases results in elimination of giant cells and new bone formation. Neoplastic stromal cells of GCTB harbor mutation of histone 3.3 and have pre-osteoblastic properties and thus express SATB2. Objectives. To (1) analyze histological changes in post-denosumab-treated GCTB, (2) analyze expression of H3.3G34W and SATB2 in pre- and post-denosumab-treated samples, and (3) to discuss why changes occur in the expression of not only H3.3G34W but also SATB2. Materials and Methods. Hematoxylin and eosin slides of 19 cases of denosumab-treated GCTB were reviewed. Immunohistochemical stains H3.3G34W and SATB2 were performed. The number of positive mononuclear cells were counted and graded. Results. Complete absence of osteoclast-like giant cells (OCLGCs) was noted in most cases along with a fibro-osseous component merging with peripheral shell of reactive bone. Irregular trabeculae of woven bone and osteoid with focal osteoblastic rimming was seen. Spindle cells were arranged predominantly in fascicular pattern. Morphometric analysis of H3.3G34W showed a mean of 68.8% positive stromal cells in pretreatment and a mean of 26.9% positive stromal cells in posttreated specimens with a statistically significant P value (.001). Mean percentage of SATB2-positive stromal cells in the pre- and posttreatment specimens was 36.46% and 20.8%, respectively. Conclusions. Our study validates that denosumab treatment results in marked reduction of OCLGCs with increased osteoblastic activity. Decreased expression of H3.3G34W in posttreatment may be a result of decreased antigenicity of neoplastic mononuclear cells. No significant change in SATB2 expression was noted.

Pre-operative denosumab is associated with higher risk of local recurrence in giant cell tumor of bone: a systematic review and meta-analysis

Background

In 2013, denosumab was introduced as peri-operative adjuvant treatment for giant cell tumor (GCT) of bone as it inhibits osteoclast activity. It is suggested that denosumab relives pain, facilitate curettage in lesions requiring resection initially. However, controversy remains whether denosumab increases the risk of local recurrence after surgery.

Methods

Medline, Embase and the Cochrane Library were comprehensively searched in June 2019 to identify studies investigating the clinical outcome of GCT of bone with and without peri-operative denosumab after surgery. Data were gathered and a meta-analysis was conducted.

Result

Ten studies with 1082 cases (169 in denosumab group, 913 in control group) were included. Overall, denosumab was associated with significantly higher risk of recurrence(P < 0.02) and inferior 5 year recurrence free survival(P = 0.000). Denosumab and curettage has a relatively higher risk of recurrence comparing to curettage alone(P = 0.07). The risk of recurrence is not significantly increased if denosumab was administered both preoperatively and postoperatively(P = 0.24).

Conclusion

Administration of denosumab is associated with increased risk of recurrence due to a variety of reasons, though it is proven effective in relieving pain, enabling curettage and improved functional outcome. Post-operative denosumab is recommended as it continuously suppress/eliminate residue tumor cells.

Sphenoid Sinus Giant Cell Tumor: A Case Report and Literature Review

We describe a 27-year-old female with a giant cell tumor of her sphenoid sinus, presenting with nasal obstruction and cranial neuropathies. Both the surgical and subsequent medical management are reviewed. Additionally, we review the overall presentation, pathophysiology, and management of giant cell tumors of the skull base. Current treatment recommendations are presented.

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.

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.