Denosumab and giant cell tumour of bone-a review and future management considerations

Establishment and characterization of NCC-GCTB14-C1 and NCC-GCTB15-C1: two novel patient-derived cell lines of giant cell tumor of bone

Giant cell tumor of bone (GCTB) is a rare bone tumor that is genetically characterized by a unique mutation in the H3-3A gene. Curative surgical resection is the standard treatment. Unfortunately, a considerable proportion of patients with GCTB have local recurrence and pulmonary metastasis after surgical treatment, and current chemotherapy treatments have shown non-effective. Considering the heterogeneity of the disease, patient-derived cancer models established from multiple cases are required. Therefore, we aimed to establish novel GCTB cell lines for use in preclinical studies. In this study, we successfully established two GCTB cell lines, NCC-GCTB14-C1 and NCC-GCTB15-C1. Both cell lines retained the genetic characteristics of the original tumors, constantly proliferated, and exhibited migratory activity. These cells formed spheroids with morphologically variable phenotypes. We found that they were compatible with chemosensitivity assays, and drug screening using these cell lines led to the identification of potential therapeutic candidates for GCTB. Therefore, NCC-GCTB14-C1 and NCC-GCTB15-C1 may be useful for elucidating the pathogenesis of and developing novel treatments for GCTB.

Comprehensive Insights into Chondroblastoma Metastasis: Metastatic Patterns and Therapeutic Approaches

Chondroblastoma metastasis, though rare, represents a clinically significant and notably important aspect of bone tumors. Understanding its epidemiological characteristics, pathological features, and treatment modalities, despite its infrequency, is imperative for comprehensive patient management. This review aims to elucidate the epidemiology, molecular mechanisms, diagnostic challenges, and therapeutic strategies associated with chondroblastoma metastasis. The patterns, prognostic factors, and treatment outcomes were explored through an analysis of case studies and clinical reports. Notably, we highlighted emerging therapeutic perspectives aimed at improving patient outcomes. To the best of our knowledge, there has been no previous review addressing these matters cumulatively, highlighting a significant gap in the existing scholarly literature. By shedding light on the nuances of chondroblastoma metastasis, this review contributes to the advancement of knowledge in this field and informs clinical decision-making for improved patient care.

Giant Cell Tumor of the Temporal Bone with Direct Invasion into the Middle Ear and Skull Base: A Case Report

Giant cell tumor (GCT) of bone is a rare, benign, osteolytic neoplasm that most commonly occurs in early adulthood and often involves the long bones of the body. Although GCT largely affects the epiphyses of long bones, several reports of GCT involvement of the cranial and facial bones exist in the literature. In addition to reviewing other reported cases of GCT of the lateral skull base in the literature, the authors report here on the clinical presentation, radiographic findings, and management of a patient found to have a GCT of the squamous part of temporal bone invading the middle ear and infratemporal fossae, which was treated by en bloc resection of the lateral skull base.

Unusual Multiple Recurrences of Soft Tissue Giant Cell Tumors in a Patient Above 60 Years

Primary giant cell tumors of soft tissues (GCT-ST) are rare neoplasms that share histopathological and immunohistochemical characteristics with osseous giant cell tumors. While GCT-ST generally exhibits a benign progression and can affect individuals of various ages, older patients may face a higher risk of recurrence and aggressive disease progression. In this case report, we present the case of a 63-year-old woman who experienced recurrent GCT-ST nine months after the complete excision of an initially localized tumor. Despite the mainstay treatment of GCT-ST being tumor-free margin surgical excision, this case demonstrates the occurrence of recurrences. The etiology of recurrence in GCT-ST remains unclear, highlighting the need for further studies and careful patient follow-up to prevent potential complications such as lung metastasis or widespread metastasis. Thus, this report aims to raise awareness of these tumors and emphasize the importance of diligent patient follow-up to facilitate early identification and management, thereby preventing potential complications such as lung or widespread metastasis.

Postoperative Fracture Risk in Giant Cell Tumor: A Case Report and Review of Literature

Giant cell tumor (GCT) of the proximal femur poses various challenges in its management and recurrence. We present a rare case of GCT of proximal femur in which recurrence and coxa vara deformity were encountered after index surgery. Management of the recurrence was done with intramedullary fixation with extended curettage and bone grafting. Different aspects of management such as the role of defect size, adjuvants, bone cement/bone graft, implants, and bisphosphonates have been highlighted in this article.

Treatment of pelvic giant cell tumor by wide resection with patient-specific bone-cutting guide and reconstruction with 3D-printed personalized implant

BACKGROUND

This study reports our experience in the treatment of aggressive pelvic GCT through wide resection assisted with patient-specific bone-cutting guides (PSBCGs) and subsequent reconstruction with 3D-printed personalized implants (3DPIs), aiming to present the operative technique of this method and evaluate its clinical efficacy.

METHODS

We retrospectively analyzed seven patients who underwent wide resection of pelvic GCT followed by reconstruction with 3DPIs from August 2019 to February 2021. There were two males and five females, with a mean age of 43 years. PSBCGs and 3DPIs were prepared using 3D-printing technology. The operational outcomes, local recurrence, radiological results, and any associated complications of this technique were assessed. And the functional outcomes were assessed according to the Musculoskeletal Tumor Society (MSTS) 93 functional score.

RESULTS

The mean follow-up time was 35.3 months (range 28-45 months). There was no intraoperative complication. Negative surgical margins were achieved in all patients. Postoperative pelvic radiographs showed that 3DPIs matched the shape and size of the bone defect. The anterior-posterior, inlet, and outlet pelvic radiograph demonstrated precise reconstruction consistent with the surgical planning. In addition, tomosynthesis-Shimadzu metal artifact reduction technology (T-SMART) showed good osseointegration at an average of three months after surgery (range 2-4 months). There was no local recurrence or tumor metastasis. The average MSTS score was 24.4 (range 23-27) at the last follow-up. Delayed wound healing was observed in one patient, and the wounds healed after debridement. Prosthesis-related complications were not detected during the follow-up, such as aseptic loosening or structure failure.

CONCLUSIONS

The treatment of aggressive pelvic GCTs through wide resection assisted with PSBCGs and subsequent reconstruction with 3DPIs is a feasible method, which provides good clinical results and reasonable functional outcomes.

The Rare Occurrence of Giant Cell Tumor of the Proximal Tibia With Pathological Fracture in an Elderly Male: A Case Report

Giant cell tumor of the bone (GCTB) is a benign bone tumor that can occasionally progress to malignancy, usually in chronic cases. It is a common benign and aggressive bone tumor that affects patients aged between 20 and 45 years. The most common location is the knee joint. It manifests as a painless or occasionally painful swelling over the affected area. A case of giant cell tumor (GCT) of the proximal tibia in a 72-year-old male is reported here, which was difficult to diagnose as it is rarely found in the geriatric age group. The patient came with a chief complaint of pain and swelling over his left knee for two months with a history of trauma to the knee a couple of times. On clinical examination, the patient had grade 3 tenderness and swelling on the anterolateral aspect of the knee extending toward the proximal tibia. The swelling was well-defined, smooth, firm, and uniform in consistency with dimensions of 15 cm × 12 cm. The swelling was moveable sideways, and the movement of the knee suggested that it was not attached to the underlying bone. As per the age and history of the rapid-growing lesion, we suspected malignancy, but clinical findings were pointing toward benign tumor. X-ray of the affected knee was done, which revealed a soft tissue mass with the involvement of the bone. Magnetic resonance imaging (MRI) of the knee revealed a soft tissue mass with the cortical breach. An open biopsy was done for the confirmation of the diagnosis, which was later reported and confirmed as a giant cell tumor of the proximal tibia. As bone tumor is associated with a cortical breach and pathological fracture, it was classified under Campanacci grade 3, for which an en bloc resection and open reduction and internal fixation with plate osteosynthesis with bone cementing and bone grafting were done followed by knee bending physiotherapy and gradual weight-bearing. Finally, the knee function was improved with pain relief.

Treatment of Recurrent Giant Cell Tumor of Bones: A Systematic Review

The giant cell tumor of bones (GCTB) is a benign bone tumor with high postoperative recurrence potential. No specific treatment protocol has been developed to date in case of tumor recurrence, and the kind of re-operative surgery depends upon the surgeon's preferences. The aim of this systematic review is to determine the second recurrence rate and the respective functional results of the available treatment options applied to recurrent GCTB. Medline/PubMed and Scopus were searched to identify articles published until March 2023. Twelve studies fulfilled the inclusion criteria, comprising 458 patients suffering from recurrent GCTB. The overall incidence of second recurrence was 20.5%, at a mean interval of 28.8 months after the first surgery, and it was more evident after intralesional curettage (IC) surgery than en-bloc resection (EBR) (p = 0.012). In the IC group of patients, the second recurrence rate was lower and the functional outcome was greater when polymethylmethacrylate cement (PMMAc) was used as an adjuvant instead of bone grafting (p < 0.001 for both parameters). Reconstruction of the created bone defect after EBR with a structural allograft provided a better outcome than prosthesis (p = 0.028). According to this systematic review, EBR (first choice) and IC with PMMAc (second choice) are the best treatment options for recurrent GCTB.

Single-Centre Experience Regarding the Use of Fibular Graft for Reconstruction after Resection of Grade III GCT of Distal Radius

Background: A giant cell tumour (GCT) is a locally invasive benign tumour of bone in young adults. Treatment includes surgical resection as first-line or denosumab pharmacotherapy in inoperable patients. However, surgical resection of distal radius GCT has produced debatable functional outcomes. Here we study the use of fibular grafts for reconstruction of surgically resected GCT of the distal radius. Methods: A total of 11 patients having Grade III GCT of the distal radius were recruited for a retrospective single-centred study. Five underwent arthrodesis with fibular shaft graft and six received arthroplasty with the proximal fibula. Functional outcomes at 6 weeks, 6 and 12 months were measured by Mayo wrist score (MWS) (>51% = good) and Revised Musculoskeletal tumor society (MSTS) score (>15 = good). Results: At 6 weeks, mean MSTS score and MWS were 23.64 and 58.64% respectively, and the length of the fibular graft was a predictor for both MSTS score (p = 0.014) and MWS (p = 0.006). At 6 months, the mean MSTS and MWS were 26.36 and 76.82%, respectively. At 6 months, the surgical procedure was a predictor in MSTS score (p = 0.02) while MWS was predicted by length of graft (p = 0.02). At 12 months, MSTS score was 28.73, and MWS remained 91.82%. Length of the fibular graft was an insignificant predictor, but a significant risk factor was surgical procedure for MWS (p = 0.04) at 12 months. No variable was found significant for MSTS score. Conclusions: Resection along with reconstruction of Grade III GCT of the radius with fibular graft was found an optimal treatment option. Also, use of the fibular head grafts and shorter length grafts are predictors for better outcomes after surgery. Level of Evidence: Level IV (Therapeutic).

Giant cell tumor of bone: An update, including spectrum of pathological features, pathogenesis, molecular profile and the differential diagnoses

Giant cell tumor of bone (GCTB) is an enigmatic tumor. Despite its benign histological appearance and clinical behavior in most cases, it is associated with recurrences, uncommonly metastasis, and rarely with a malignant transformation. During the last few years, there has been a significant evolution in the diagnosis and management of GCTB, including discoveries related to the underlying pathogenesis (RANK/RANK/OPG pathway), with treatment-related implications in the form of denosumab (approved inhibitor for targeting RANKL), leading to improved surgical resections, especially in cases of recurrent, large and borderline resectable tumors. Lately, a specific Histone mutation, namely H3.3G34W underlying almost all GCTBs has been discovered, further leading to the identification of a highly sensitive and specific immunohistochemical antibody marker, H3.3G34W, which is very useful for an exact diagnosis of a GCTB, including its differentiation from its various mimics, which has significant implications. This review describes clinicopathological features of a GCTB, including its variable features, recent concepts, underlying pathogenesis, post-denosumab related changes and various entities that constitute its differential diagnosis, including their molecular signatures, with treatment-related implications.

A rare case of sphenoid giant cell tumor: Case report & review of imaging features post short-term denosumab treatment

Background: Giant cell tumors (GCTs) are locally aggressive but rarely malignant bone neoplasms that uncommonly involve the skull. In this report, we describe a tumor of the sphenoid sinus. Case presentation: A 51-year-old female was presented with headache, and bilateral decreased visual acuity, CT scan, and brain MRI revealed an infra-sellar enhancing tumor expanding to the sellar and supra-sellar region which proved to be a GCT. the patient had received 03 months of preoperative denosumab-based treatment and imaging follow-up showed regression in size and morphology modifications of tumor tissue. Conclusion: This is one of few reports to describe the appearance of sphenoid bone GCT, and the first report to highlight the effects of short-term denosumab treatment in GCTb in such a location.

Giant Cell Tumor of Talus - A Case Report

Introduction

A giant cell tumor (GCT) is a benign tumor of bones which commonly arises from epiphysis of long bones. The tumor is locally aggressive and rarely metastasizes to the lungs. GCT of small bones of the foot and ankle is very rare. The GCT of the talus is very rare, and only a few case reports and series are described in the literature. In general, the GCT is monostotic, and few incidences of multicentricity have been described in the foot and ankle bones literature. Here are the findings of our case GCT of talus and reviews of earlier literature.

Case Report

We present a case of a GCT of the talus in a 22-year-old female. Patient presented with pain in ankle with mild swelling and tenderness at ankle. Radiograph and Computer tomography scan conformed an eccentric osteolytic lesion on anterolateral part of talus body. Magnetic resonance imaging showed no extra osseous extension or articular surface breach. Biopsy conformed the lesion to be giant cell tumor. The tumor was reated with curettage and bone cement filling.

Conclusion

Giant cell tumor of talus is extremely rare and presentation of these tumor may change. Curettage and bone cementing are an effective method of treatment. It gives early weight bearing and rehabilitation.

Interventions for managing medication-related osteonecrosis of the jaw

BACKGROUND

Medication-related osteonecrosis of the jaw (MRONJ) is a severe adverse reaction experienced by some individuals to certain medicines commonly used in the treatment of cancer and osteoporosis (e.g. bisphosphonates, denosumab, and antiangiogenic agents), and involves the progressive destruction of bone in the mandible or maxilla. Depending on the drug, its dosage, and the duration of exposure, this adverse drug reaction may occur rarely (e.g. following the oral administration of bisphosphonate or denosumab treatments for osteoporosis, or antiangiogenic agent-targeted cancer treatment), or commonly (e.g. following intravenous bisphosphonate for cancer treatment). MRONJ is associated with significant morbidity, adversely affects quality of life (QoL), and is challenging to treat. This is an update of our review first published in 2017.

OBJECTIVES

To assess the effects of interventions versus no treatment, placebo, or an active control for the prophylaxis of MRONJ in people exposed to antiresorptive or antiangiogenic drugs. To assess the effects of non-surgical or surgical interventions (either singly or in combination) versus no treatment, placebo, or an active control for the treatment of people with manifest MRONJ.

SEARCH METHODS

Cochrane Oral Health's Information Specialist searched four bibliographic databases up to 16 June 2021 and used additional search methods to identify published, unpublished, and ongoing studies.  SELECTION CRITERIA: We included randomised controlled trials (RCTs) comparing one modality of intervention with another for the prevention or treatment of MRONJ. For 'prophylaxis of MRONJ', the primary outcome of interest was the incidence of MRONJ; secondary outcomes were QoL, time-to-event, and rate of complications and side effects of the intervention. For 'treatment of established MRONJ', the primary outcome of interest was healing of MRONJ; secondary outcomes were QoL, recurrence, and rate of complications and side effects of the intervention.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened the search results, extracted the data, and assessed the risk of bias in the included studies. For dichotomous outcomes, we reported the risk ratio (RR) (or rate ratio) and 95% confidence intervals (CIs).

MAIN RESULTS

We included 13 RCTs (1668 participants) in this updated review, of which eight were new additions. The studies were clinically diverse and examined very different interventions, so meta-analyses could not be performed. We have low or very low certainty about available evidence on interventions for the prophylaxis or treatment of MRONJ. Prophylaxis of MRONJ Five RCTs examined different interventions to prevent the occurrence of MRONJ. One RCT compared standard care with regular dental examinations at three-month intervals and preventive treatments (including antibiotics before dental extractions and the use of techniques for wound closure that avoid exposure and contamination of bone) in men with metastatic prostate cancer treated with zoledronic acid. The intervention seemed to lower the risk of MRONJ (RR 0.10, 95% CI 0.02 to 0.39, 253 participants). Secondary outcomes were not evaluated. Dentoalveolar surgery is considered a common predisposing event for developing MRONJ and five RCTs tested various preventive measures to reduce the risk of postoperative MRONJ. The studies evaluated plasma rich in growth factors inserted into the postextraction alveolus in addition to standardised medical and surgical care versus standardised medical and surgical care alone (RR 0.08, 95% CI 0.00 to 1.51, 176 participants); delicate surgery and closure by primary intention versus non-traumatic tooth avulsion and closure by secondary intention (no case of postoperative MRONJ in either group); primary closure of the extraction socket with a mucoperiosteal flap versus application of platelet-rich fibrin without primary wound closure (no case of postoperative MRONJ in either group); and subperiosteal wound closure versus epiperiosteal wound closure (RR 0.09, 95% CI 0.00 to 1.56, 132 participants).  Treatment of MRONJ Eight RCTs examined different interventions for the treatment of established MRONJ; that is, the effect on MRONJ cure rates.  One RCT analysed hyperbaric oxygen (HBO) treatment used in addition to standard care (antiseptic rinses, antibiotics, and surgery) compared with standard care alone (at last follow-up: RR 1.56, 95% CI 0.77 to 3.18, 46 participants).  Healing rates from MRONJ were not significantly different between autofluorescence-guided bone surgery and conventional bone surgery (RR 1.08, 95% CI 0.85 to 1.37, 30 participants). Another RCT that compared autofluorescence- with tetracycline fluorescence-guided sequestrectomy for the surgical treatment of MRONJ found no significant difference (at one-year follow-up: RR 1.05, 95% CI 0.86 to 1.30, 34 participants).  Three RCTs investigated the effect of growth factors and autologous platelet concentrates on healing rates of MRONJ: platelet-rich fibrin after bone surgery versus surgery alone (RR 1.05, 95% CI 0.90 to 1.22, 47 participants), bone morphogenetic protein-2 together with platelet-rich fibrin versus platelet-rich fibrin alone (RR 1.10, 95% CI 0.94 to 1.29, 55 participants), and concentrated growth factor and primary wound closure versus primary wound closure only (RR 1.38, 95% CI 0.81 to 2.34, 28 participants).   Two RCTs focused on pharmacological treatment with teriparatide: teriparatide 20 μg daily versus placebo in addition to standard care (RR 0.96, 95% CI 0.31 to 2.95, 33 participants) and teriparatide 56.5 μg weekly versus teriparatide 20 μg daily in addition to standard care (RR 1.60, 95% CI 0.25 to 1.44, 12 participants).

AUTHORS CONCLUSIONS

Prophylaxis of medication-related osteonecrosis of the jaw One open-label RCT provided some evidence that dental examinations at three-month intervals and preventive treatments may be more effective than standard care for reducing the incidence of medication-related osteonecrosis of the jaw (MRONJ) in individuals taking intravenous bisphosphonates for advanced cancer. We assessed the certainty of the evidence to be very low. There is insufficient evidence to either claim or refute a benefit of the interventions tested for prophylaxis of MRONJ in patients with antiresorptive therapy undergoing dentoalveolar surgery. Although some interventions suggested a potential large effect, the studies were underpowered to show statistical significance, and replication of the results in larger studies is pending. Treatment of medication-related osteonecrosis of the jaw The available evidence is insufficient to either claim or refute a benefit, in addition to standard care, of any of the interventions studied for the treatment of MRONJ.

Malignant Transformation of Giant Cell Tumor of Bone and the Association with Denosumab Treatment: A Radiology and Pathology Perspective

Objective

Malignancy in giant cell tumor of bone (mGCTB) is categorized as primary (concomitantly with conventional GCTB) or secondary (after radiotherapy or other treatment). Denosumab therapy has been suggested to play a role in the etiology of secondary mGCTB. In this case series from a tertiary referral sarcoma center, we aimed to find distinctive features for malignant transformation in GCTB on different imaging modalities. Furthermore, we assessed the duration of denosumab treatment and lag time to the development of malignancy.

Methods

From a histopathology database search, 6 patients were pathologically confirmed as having initial conventional GCTB and subsequently with secondary mGCTB.

Results

At the time of mGCTB diagnosis, 2 cases were treated with denosumab only, 2 with denosumab and surgery, 1 with multiple curettages and radiotherapy, and 1 with surgery only. In the 4 denosumab treated patients, the mean lag time to malignant transformation was 7 months (range 2–11 months). Imaging findings suspicious of malignant transformation related to denosumab therapy are the absence of fibro-osseous matrix formation and absent neocortex formation on CT, and stable or even increased size of the soft tissue component.

Conclusion

In 4 patients treated with denosumab, secondary mGCTB occurred within the first year after initiation of treatment. Radiotherapy-associated mGCTB has a longer lag time than denosumab-associated mGCTB. Close clinical and imaging follow-up during the first months of denosumab therapy is key, as mGCTB tends to have rapid aggressive behavior, similar to other high-grade sarcomas. Nonresponders should be (re) evaluated for their primary diagnosis of conventional GCTB.

Diagnosis and Treatment of Lumbar Giant Cell Tumor of the Spine: Update on Current Management Strategies

(1) Background: Giant Cell Tumor of the spine remains a difficult tumor to treat. Recent advances in adjuvant therapy such as denosumab and innovations in surgical technique in the last 5 years have given providers new options for treatment after a successful diagnosis of the tumor. (2) Methods: Articles published between 1927 and 2021 were selected from PubMed and Scopus searches using key words “Giant Cell Tumor” AND “Lumbar Spine” AND “Treatment”. Relevant articles were reviewed and selected by the authors. (3) Results: A total of 191 articles were discovered. Complete en bloc spondylectomy remains the most definitive treatment option; however, this surgery is challenging and carries a high rate of complication. New adjuvant therapies including denosumab offer a viable alternative to surgery. (4) En bloc spondylectomy remains the gold standard treatment for Giant Cell Tumor of the spine with the lowest published recurrence rate. The use of (neo)adjuvant denosumab improves recurrence rates. More data are needed to determine if denosumab alone is a viable standalone definitive treatment.

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.

Establishment and characterization of the NCC-GCTB4-C1 cell line: a novel patient-derived cell line from giant cell tumor of bone

Giant cell tumor of bone (GCTB) is a rare osteolytic intermediate bone tumor that harbors a pathogenic H3F3A gene mutation and exhibits characteristic histology. The standard curative treatment for GCTB is complete surgical resection, but it frequently results in local recurrence and, more rarely, metastasis. Therefore, effective multidisciplinary treatment is needed. Although patient-derived tumor cell lines are promising tools for preclinical and basic research, there are only four available cell lines for GCTB in public cell banks. Thus, the aim of this study was to establish a novel GCTB cell line. Using surgically resected tumor tissues from a patient with GCTB, we established a cell line named NCC-GCTB4-C1. The cells harbored the typical H3F3A gene mutation and exhibited constant proliferation and invasive capabilities. After characterizing NCC-GCTB4-C1 cell behaviors, we conducted high-throughput screening of 214 anti-tumor drugs and identified seven effective drugs. Comparing the results of high-throughput screening using NCC-GCTB4-C1 cell line with the results using NCC-GCTB1-C1, NCC-GCTB2-C1, and NCC-GCTB3-C1 cell lines that we previously established, four drugs were in common effective. This study showed potential drugs for the treatment of GCTB. These data indicate that NCC-GCTB4-C1 has the potential to be a powerful tool in preclinical and basic research on GCTB.

Role of Zoledronic Acid Supplementation in Reducing Post-Surgical Recurrence of Giant Cell Tumor of Bone: A Meta-Analysis of Comparative Studies

Zoledronic acid is a bisphosphonate that has recently gained interest in adjuvant therapy for giant cell tumor of bone (GCTB). It has an apoptotic effect on osteoclasts that are precursors of GCTB. However, the evidence suggesting the role of zoledronic acid in preventing GCTB recurrence is mixed, and therefore, a consensus is yet to be established. The purpose of the current meta-analysis was to analyze the impact of zoledronic acid supplementation on tumor recurrence in surgical treated GCTB.

A systematic search was conducted on PubMed, Embase, and Web of Science databases to identify studies that analyzed the impact of local or systemic zoledronic acid supplementation on clinical outcomes in surgically treated GCTB. The data from the comparative studies were pooled and analyzed to investigate the association of zoledronic acid supplementation with tumor recurrence. Additionally, other factors such as age, gender, soft tissue extension, polymethyl methacrylate (PMMA) cement application, recurrent presentation, and extended curettage were also investigated for any association with tumor recurrence.

Of the 271 results, 13 unique studies reported the clinical outcomes in GCTB. Seven studies compared the outcomes of zoledronic acid supplementation with control groups. Six studies presented the tumor recurrence-related data among the comparison groups. The zoledronic acid supplementation was associated with significantly lower tumor recurrence rates (p = 0.007). Additionally, a significant association of soft tissue extension and non-usage of PMMA cement with tumor recurrence were observed.

The current meta-analysis suggests that zoledronic acid supplementation reduces tumor recurrence rates in surgically treated GCTB. We, therefore, recommend the use of zoledronic acid following aggressive extended curettage of the tumor. Further, well-planned randomized controlled trials will help strengthen this evidence.

Combination of Melatonin and Zoledronic Acid Suppressed the Giant Cell Tumor of Bone in vitro and in vivo

Melatonin (Mlt) confers potential antitumor effects in various types of cancer. However, to the best of our knowledge, the role of Mlt in the giant cell tumor of bone (GCTB) remains unknown. Moreover, further research is required to assess whether Mlt can enhance the therapeutic effect of zoledronic acid (Zol), a commonly used anti-GCTB drug. In this research, we investigated the effects of Mlt, Zol, and the combination of these two drugs on GCTB cells’ characteristics, including cell proliferation, apoptosis, osteogenic differentiation, migration, and invasion. The cell counting kit-8 (CCK-8) assay, colony formation assay, terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling assay (TUNEL), alkaline phosphatase (ALP) staining, alizarin red staining (ARS), scratch wound healing assay, and transwell experiment were performed, respectively. Our results showed that Mlt could effectively inhibit the proliferation, migration, and invasion of GCTB cells, as well as promote the apoptosis and osteogenic differentiation of tumor cells. Of note, a stronger antitumor effect was observed when Mlt was combined with Zol treatment. This therapeutic effect might be achieved by inhibiting the activation of both the Hippo and NF-κB pathways. In conclusion, our study suggests that Mlt can be a new treatment for GCTB, which could further enhance the antitumor effect of Zol.

Use of three-dimensional-printed custom-made prosthesis to treat unicondylar femoral defect secondary to pathological fracture caused by giant cell tumor

Objective

To evaluate the short-term effectiveness of using a three-dimensional (3D)-printed custom-made prosthesis to repair unicondylar femoral defects.

Methods

We retrospectively reviewed 26 patients with a primary pathological fracture of the distal femur caused by a giant cell tumor. All patients had unicondylar defects involving the articular surface. Twelve patients were treated with a 3D-printed custom-made prosthesis to repair the unicondylar defect (3D-printed group). The other 14 patients were treated with total knee replacement (TKR group). The operation time, blood loss, Musculoskeletal Tumor Society score, range of motion, local recurrence, and complications were statistically compared.

Results

The operation time was significantly shorter and the blood loss was significantly less in the 3D-printed group than in the TKR group. The Musculoskeletal Tumor Society scores were significantly higher in the 3D-printed group than in the TKR group from 3 to 24 months postoperatively. The range of motion was significantly better in the 3D-printed group than in the TKR group at 6 and 9 months postoperatively.

Conclusions

3D-printed custom-made prostheses provide better short-term functional results than does TKR.

Fibular Strut Arthrodesis for Salvage of Campanacci Grade III Giant Cell Tumor of the Hallucal Proximal Phalanx: A Case Report

Involvement of toe phalanges by giant cell tumor (GCT) is extremely rare; tumors in these locations tend to be aggressive. Whereas aggressive GCTs of the distal phalanx may be managed successfully by en-bloc resection without reconstruction or amputation, management of these lesions, when they involve the proximal phalanx, can be challenging. We present a Campannaci grade III GCT of the hallucal proximal phalanx in a 14-year old girl that had breached into the dorsal soft tissues and the metatarso-phalangeal joint. Wide local resection of the proximal phalanx along with reconstruction arthrodesis with an autologous, non-vascularized fibular strut graft was performed. There was no recurrence at 3 years of follow-up. The patient had an excellent functional outcome. To the best of our knowledge, this is the first case reporting the outcomes of fibular strut arthrodesis for salvage of GCT of the hallucal proximal phalanx.

Treatment of Chondroblastoma with Denosumab: A Case Report with a Correlative Analysis of Effect on the RANK Signaling Pathway

CASE

A 15-year-old boy with chondroblastoma of the right hemipelvis presented with significant periacetabular bone destruction. Neoadjuvant denosumab treatment facilitated initial joint preserving surgery. Unfortunately, he experienced 2 local recurrences and underwent wide surgical resection 2 years after his initial diagnosis.

CONCLUSION

Inhibition of the receptor activator of NF-κB (RANK)/RANK ligand (RANK-L) pathway with denosumab has been used neoadjuvantly for the treatment of giant cell tumor of bone, but its role in the treatment of chondroblastoma is less understood. This patient's clinical response and effect on cellular RANK/RANK-L activity support the consideration of denosumab in the treatment algorithm for other osteolytic bone tumors such as chondroblastoma.

Efficacy of percutaneous vertebroplasty for the relief of osteoblastic spinal metastasis pain

The aim of the present manuscript was to retrospectively evaluate the efficacy of fluoroscopy-guided percutaneous vertebroplasty (PVP) for the relief of osteoblastic spinal metastases pain. PVP was performed in 39 consecutive patients with 82 osteoblastic metastatic spinal vertebras. 19 vertebras had pathologic compressive fracture and the other 63 vertebras had no compressive fracture with obvious imaging abnormalities. The ages of the patients ranged from 40 to 77 years with a mean age of 58.5±9.0 years. Visual analog scale (VAS) and QLQ-BM22 score were used to evaluate pain and quality of life at 2 days pre-operation and at 1 week and 3 months post-operation. Among all 82 vertebras, 35 vertebras had been injected bilaterally and the other 47 vertebras unilaterally. The amount of cement injected per lesion ranged from 0.5 to 4.5 ml with a mean volume of 1.6±0.8 ml. Cement deposition in all lesions was uniform. The patients were followed up from 3 to 15.5 months with a mean follow up time of 5.6±3.4 months. Mean VAS score declined significantly from preoperative 4.3±2.4 to postoperative 3.0±1.7 at 1 week and 2.4±2.0 at 3 months after the procedure (P=0.001). Mean QLQ-BM22 score declined significantly from preoperative 49.1±12.3 to postoperative 42.4±9.5 at 1 week and 39.6±10.4 at 3 months after the procedure (P<0.001). Extraosseous cement leakage occurred in 21 vertebras of 13 cases and in 1 case into the thoracic vertebra canal without causing any clinical complications. No further procedures were performed after leakage. PVP is an effective treatment for painful osteoblastic spinal metastases. It can relieve pain, reduce disability and improve function. The main complications are bone cement leakage and incomplete pain relief.

Radiological Assessment of Giant Cell Tumour of Bone in the Sacrum: From Diagnosis to Treatment Response Evaluation

Giant cell tumour of bone (GCTB) typically occurs in young adults from 20-40 years old. Although the majority of lesions are located in the epi-metaphyses of the long bones, approximately one third of tumours is located in the axial skeleton, of which only 4% in the sacrum. Sacral tumours tend to be large at the time of presentation, and they present with aggressive features such as marked cortical destruction and an associated soft tissue component. The 2020 World Health Organisation classification of Soft Tissue and Bone Tumours describes GCTB as neoplasm which is locally aggressive and rarely metastasizing. The tumour contains three different cell types: neoplastic mononuclear stromal cells, macrophages and osteoclast-like giant cells. Two tumour subtypes were defined: conventional GCTB and malignant GCTB. Only 1-4% of GCTB is malignant. In this review article, we will discuss imaging findings at the time of diagnosis to guide the musculoskeletal radiologist in reporting these tumours. In addition, imaging for response evaluation after various treatment options will be addressed, such as surgery, radiotherapy, embolization and denosumab. Specific findings will be presented per imaging modality and illustrated by cases from our tertiary sarcoma referral center. Common postoperative and post radiotherapy findings in GCTB of the sacrum on MRI will be discussed.

The Role of Denosumab for Surgical Outcomes in Patients with Giant Cell Tumour of Bone: A Systematic Review

Background: The role of denosumab in patients with resectable giant cell tumour of bone remains unclear. We asked the following research question: for patients (aged ≥ 12 years) with resectable giant cell tumour of bone, what are the benefits and harms of denosumab compared with no denosumab in terms of (1) facilitation of surgery (operative time, blood loss), (2) disease recurrence, (3) pain control, (4) disease stability, and (5) adverse effects (e.g., malignant transformation, osteonecrosis of jaw, atypical femur fracture)? One previous systematic review addressed only one outcome-disease recurrence. Therefore, we undertook this new systematic review to address the above five outcomes. Methods: MEDLINE, EMBASE, PubMed, and Cochrane Database of Systematic Reviews databases were searched on June 30, 2020. Results: This systematic review included one previous systematic review and five comparative studies. Due to poor quality, non-randomized studies fraught with selection bias, it is difficult to determine if a significant difference exists in the outcomes for surgical giant cell tumour of bone with perioperative denosumab. There were no reported cases of adverse effects from denosumab. Conclusion: To date, there is insufficient evidence to understand the value of denosumab in the perioperative setting in patients with giant cell tumour of bone.

Is a Short-course of Preoperative Denosumab as Effective as Prolonged Therapy for Giant Cell Tumor of Bone?

BACKGROUND

Denosumab is an inhibitor of monoclonal receptor activator of nuclear factor-ĸB ligand, approved to treat giant cell tumors of bone (GCTB). It is commonly used for unresectable tumors and for downstaging the tumor to perform less-morbid procedures. Although denosumab has been used extensively for GCTBs, there are no recommendations regarding the duration of therapy. The risk factors associated with local recurrence (LR) in patients receiving preoperative denosumab for GCTB also are unknown.

QUESTIONS/PURPOSES

(1) Is short-course (three doses or fewer) preoperative denosumab treatment as effective as longer course (more than three doses) of treatment in terms of achieving a clinical, radiologic, and histologic response in patients with GCTB? (2) Is there an increased risk of LR after short-course denosumab therapy compared with long-course denosumab therapy; and after controlling for confounding variables, what factors were associated with LR after surgery for GCTB in patients receiving preoperative denosumab?

METHODS

A retrospective study was performed using an institutional database of 161 skeletally mature patients with a histologic diagnosis of GCTB who received denosumab between November 2010 and July 2019 to downstage the tumor before surgery. In general, we used denosumab when we thought it would facilitate either resection or curettage (by formation of a sclerotic rim around the osteolytic lesion), when a less-morbid procedure than initially planned might be performed, and in patients with complex presentations like cortical breech and soft tissue extension, pathological fracture, thinning of more than three cortices of the extremity. From 2010 to late 2015, denosumab was administered for approximately 4 to 6 months; starting in late 2015 through 2020, the number of denosumab doses has been reduced. We divided patients into two groups: Those who received three or fewer doses of denosumab (short-course, n = 98) and those who received more than three doses of denosumab (long-course, n = 63). Comparing those in the long-course group with those in the short-course group whose procedures were performed at least 2 years ago, there were no differences in loss to follow-up before 2 years (3% [3 of 98] versus. 3% [2 of 63]). The mean patient age was 30 years (± 6.1) and the mean number of denosumab doses was 4.4 (range 1 to 14). Overall, 77% (37 of 48) of patients taking short-course denosumab and 75% (27 of 36) of patients on long-course denosumab underwent curettage, and the remaining patients with an inadequate bony shell around the tumor or destruction of articular cartilage in both groups underwent tumor resection. With the numbers available, the patients with short- and long-course denosumab were not different in terms of age, sex, MSTS score on presentation, lesion size, lesion location, Campanacci grade, presence of pathological fracture and pulmonary metastasis on presentation, and the type of surgery performed (curettage versus resection). We analyzed the change in the Musculoskeletal Tumor Society score, change in Campanacci grade, radiologic objective tumor response (defined as a partial or complete response, per the modified inverse Choi criteria), and histologic response (defined as reduction of more than 90% of osteoclast-like giant cells or a reduction of more than 50% of mesenchymal spindle-like stromal cells, along with evidence of lamellar or woven bone formation, when compared with the biopsy sample) between the two groups (short- and long-course denosumab). LR rates were compared between the two groups, and after controlling for confounding variables, factors associated with LR in all operated patients were analyzed with a Cox proportional hazards regression analysis.

RESULTS

With the numbers available, there was no difference between the short- and long-course denosumab groups in terms of mean percentage improvement in MSTS score (20 [± 18.5] versus 24 [± 12.6]; p = 0.37), radiologic objective tumor response (90% [43 of 48] versus 81% [29 of 36]; p = 0.24) and histologic response (79% [38 of 48] versus 83% [30 of 36]; p = 0.81). With the numbers available, there was no difference between the short- and long-course denosumab groups in terms of Kaplan-Meier survivorship free from LR at 5 years after surgery (73% [95% confidence interval, 68 to 76] versus 64% [95% CI 59 to 68]; log-rank p = 0.50). After controlling for potential confounding variables like age, sex, Campanacci grade and MSTS score on presentation, number of denosumab doses administered before surgery, clinical, radiologic and histologic response to denosumab, and time duration between denosumab therapy and surgery, we found that tumors involving the bones of the hand and the foot (hazard ratio 7.4 [95% CI 2.0 to 27.3]; p = 0.009) and curettage (HR 6.4 [95% CI 2.8 to 23.0]; p = 0.037) were independently associated with a higher risk of LR.

CONCLUSIONS

In this preliminary, single-center study, we found that a short-course of preoperative denosumab (three or fewer doses) was associated with no differences in clinical scores, histological and radiological response, or LR-free survivorship, compared with longer-course of denosumab (more than three doses). Fewer preoperative doses can reduce the complications and costs associated with more-prolonged therapy. Denosumab must be used cautiously before curettage for GCTB, and only if the benefit of joint salvage outweighs the possibility of LR. However, given the small number of patients, potentially clinically important differences might have been missed, and so our findings need to be confirmed by larger, multicenter, prospective trials.

LEVEL OF EVIDENCE

Level III, therapeutic study.

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.

Radiological findings of denosumab treatment for giant cell tumours of bone

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

Management of C2 Body Giant Cell Tumor by Innovatively Fashioned Iliac Crest Graft and Modified Cervical Mesh Cage Used as Plate

BACKGROUND

Locally aggressive vertebral body tumors of the axis must be treated with wide local excision for best outcome. Reconstruction of the load-bearing vertebra needs to be done after tumor resection in such a manner so as to give stable, long-term fusion in this young population.

METHODS

We describe the management strategy of a 25-year-old acutely quadriplegic patient, with respiratory distress, with a C2 giant cell tumor. The use of a novel iliac crest graft modification used for C2 reconstruction along with a modified mesh cage used as an anterior plate has been reported.

RESULTS

The patient had a good outcome at 18 months' follow-up, with neurologic improvement and a solid fusion.

CONCLUSIONS

Iliac crest autograft is inexpensive and easy to harvest and can be considered as a C2 prosthesis, especially in a resource-constrained setting. Modified iliac crest graft can be used for load transmission from C1 lateral mass to C3 body, and the mesh cage can be modified according to need as a plate with good results in an emergency.

Giant cell tumor of bone following denosumab treatment: assessment of tumor response using various imaging modalities

Background

Giant cell tumor (GCT) is a nonmalignant neoplasm composed of multinucleated giant and mononuclear stromal cells.

This study aimed to compare imaging findings of GCT pre- and post-denosumab treatment, including lesion size, percentage of signal intensity/density change, and time of initial objective tumor response. This will have a great impact on selection of most appropriate imaging technique to accurately measure therapy response and its related complications, which would influence the physicians to tailor the treatment regimen to suit each patient.

Results

As per inverse Choi density/size (ICDS), 16 patients (84.2%) had an objective tumor response and 15 (78.9%) had an increase in density or decrease in signal intensity, and the mean of signal intensity decrease in the treated lesions was 32.4% (95% CI, 18–46.7). Only seven patients (36.8%) had tumors demonstrating ≥ 10% decrease in size, all of which showed a positive change in signal/density except for one. Moreover, 17 patients (89.4%) showed a clear demarcation/low signal intensity margin surrounding ≥ two third of the lesion periphery. The median time to first objective tumor response was approximately 23 weeks.

Conclusion

Based on the ICDS criteria, most patients with giant cell tumor of bone show objective tumor response to denosumab. Modification of ICDS to include marginal sclerosis or clear demarcation of the lesions might be considered as a separate response criterion to accurately assess the treatment response in patients with GCT.

Outcomes of En bloc resection followed by reconstruction of giant cell tumor around knee and distal radius. A case series

INTRODUCTION

This study is to evaluate the outcomes of En bloc resection and reconstruction in patients with GCT of the bone around the knee and in the distal radius.

MATERIALS AND METHODS

We reviewed 41 cases of GCT of the bone that was treated by En bloc resection around the knee joint and in the distal radius from 2011 to 2018. The local recurrence, metastases, complications and functional score were evaluated for each operation technique.

RESULTS

The average of MSTS score for all group was 78% (excellent). In the knee joint, the megaprostheses group had an excellent MSTS score of78.9% and good 21.1%. The MAMC group had an excellent MSTS score of40.0%, good 50.0% and fair 10.0%. One patient in the megaprostheses group had metastasis to the lung and 1 patient in the knee arthrodesis group has a recurrence. Infection occurred in 2 cases of megaprostheses while only 1 case in MAMC. Both of the groups in knee joint GCT had 1 patient with implant loosening. In the distal radius, FVFG group had an excellent MSTS score 100% and NVFG group had an excellent score 77.7%, good 11.1% and fair 11.1%. One patient in the NVFG group had an infection, 1 patient has implant loosening and another one patient had graft failure. Two patients in the NVFG group had a recurrence. No metastasis was found in both of the group types of surgery in distal radius GCT.

CONCLUSION

Functional outcome of a patient with GCT of the bone after En bloc resection and reconstruction with the above techniques had comparable results with previous studies.

Bisphosphonate-loaded Bone Cement as a Local Adjuvant Therapy for Giant Cell Tumor of Bone: A 1 to 12-Year Follow-up Study

BACKGROUND

Historically, nontargeted adjuvant therapies such as liquid nitrogen, phenol, argon beam, and alcohol have been applied locally after curettage of giant cell tumors (GCT) in the extremities. Systemic bisphosphonates (BP) and denosumab have emerged as osteoclast-targeting therapies because osteoclast-like giant cells, responsible for aggressive bone resorption, are susceptible to BP or denosumab. However, such drugs may cause systemic side effects. We examined the effects of an alternative intraoperative local delivery of BP on GCTs.

MATERIALS AND METHODS

In total, 17 patients with GCTs underwent extended surgical curettage procedures consisting of high-speed burring, traditional adjuvant therapy, and application of BP-loaded polymethylmethacrylate bone cement. Clinical data and follow-up radiographs were reviewed to investigate local recurrence (LR) rate and complications in a retrospective manner.

RESULTS

There were 6 males and 11 females (mean age, 33.7 y). There were no cases of pulmonary metastases. Patient follow-up ranged from 1 to 12 years. There was 1 LR during the follow-up period for an LR rate of 5.9%. The mean final Musculoskeletal Tumor Society (MSTS) score was 29. There were no systemic or localized avascular necrosis or atypical fractures related to BPs noted.

CONCLUSIONS

BP-loaded polymethylmethacrylate is a targeted local adjuvant therapy that is feasible, safe, and may reduce LRs while alleviating the risk of systemic side effects of BPs such as avascular necrosis of jaw and atypical femur fractures. Future prospective randomized clinical trials will strengthen the level of evidence of this proposed targeted therapy.

LEVEL OF EVIDENCE

Therapeutic level IV-see instructions for authors for a complete description of evidence.

Denosumab in patients with giant-cell tumour of bone: a multicentre, open-label, phase 2 study

BACKGROUND

Giant-cell tumour of bone (GCTB) is a rare, locally aggressive osteoclastogenic stromal tumour of the bone. This phase 2 study aimed to assess the safety and activity of denosumab in patients with surgically salvageable or unsalvageable GCTB.

METHODS

In this multicentre, open-label, phase 2 study done at 30 sites in 12 countries we enrolled adults and skeletally mature adolescents (aged ≥12 years) weighing at least 45 kg with histologically confirmed and radiographically measurable GCTB, Karnofsky performance status 50% or higher (Eastern Cooperative Oncology Group status 0, 1, or 2), and measurable active disease within 1 year of study enrolment. Patients had surgically unsalvageable GCTB (cohort 1), had surgically salvageable GCTB with planned surgery expected to result in severe morbidity (cohort 2), or were enrolled from a previous study of denosumab for GCTB (cohort 3). Patients received 120 mg subcutaneous denosumab once every 4 weeks during the treatment phase, with loading doses (120 mg subcutaneously) administered on study days 8 and 15 to patients in cohorts 1 and 2 (patients in cohort 3 did not receive loading doses). The primary endpoint was safety in terms of the type, frequency, and severity of adverse events; secondary endpoints included time to disease progression from cohort 1 and the proportion of patients without surgery at month 6 for cohort 2. The safety analysis set included all enrolled patients who received at least one dose of denosumab. This study is registered with ClinicalTrials.gov, number NCT00680992, and has been completed.

FINDINGS

Between Sept 9, 2008, and Feb 25, 2016, 532 patients were enrolled: 267 in cohort 1, 253 in cohort 2, and 12 in cohort 3. At data cutoff on Feb 24, 2017, median follow-up was 58·1 months (IQR 34·0-74·4) in the overall patient population, and 65·8 months (40·9-82·4) in cohort 1, 53·4 months (28·2-64·1) in cohort 2, and 76·4 months (61·2-76·5) in cohort 3. During the treatment phase, the most common grade 3 or worse adverse events were hypophosphataemia (24 [5%] of 526 patients), osteonecrosis of the jaw (17 [3%], pain in extremity (12 [2%]), and anaemia (11 [2%]). Serious adverse events were reported in 138 (26%) of 526 patients; the most common were osteonecrosis of the jaw (17 [3%]), anaemia (6 [1%]), bone giant cell tumour (6 [1%]), and back pain (5 [1%]). 28 (5%) patients had positively adjudicated osteonecrosis of the jaw, four (1%) had atypical femur fracture, and four (1%) had hypercalcaemia occurring 30 days after denosumab discontinuation. There were four cases (1%) of sarcomatous transformation, consistent with historical data. Ten (2%) treatment-emergent deaths occurred (two of which were considered treatment-related; bone sarcoma in cohort 2 and sarcoma in cohort 1). Median time to progression or recurrence for patients in cohort 1 during the first treatment phase was not reached (28 [11%] of 262 patients had progression or recurrence). 227 (92%; 95% CI 87-95) of 248 patients who received at least one dose of denosumab in cohort 2 had no surgery in the first 6 months of the study.

INTERPRETATION

The types and frequencies of adverse events were consistent with the known safety profile of denosumab, which showed long-term disease control for patients with GCTB with unresectable and resectable tumours. Our results suggest that the overall risk to benefit ratio for denosumab treatment in patients with GCTB remains favourable.

FUNDING

Amgen.

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

Background

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

Methods

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

Results

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

Conclusions

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

Giant cell tumour of the middle phalanx of the middle finger

Giant cell tumour (GCT) of bones in the hand is very rare, only 2% of all hand tumours, but unacceptably high recurrence rates (up to 90%) have been reported by several authors. Diagnosis can be challenging due to its rarity and enchondroma-mimicking characteristics. We report on a case of GCT of the middle phalanx of the left middle finger in a 49-year-old woman who underwent middle phalanx resection and reconstruction with bone grafting. At the 1-year follow-up, no evidence of recurrence was detected and the patient was pain-free.

Gαs signaling in skeletal development, homeostasis and diseases

Skeletal development is exquisitely controlled both spatially and temporally by cell signaling networks. Gα_s is the stimulatory α-subunit in a heterotrimeric G protein complex transducing the signaling of G-protein-coupled receptors (GPCRs), responsible for controlling both skeletal development and homeostasis. Gα_s, encoded by the GNAS gene in humans, plays critical roles in skeletal development and homeostasis by regulating commitment, differentiation and maturation of skeletal cells. Gα_s-mediated signaling interacts with the Wnt and Hedgehog signaling pathways, both crucial regulators of skeletal development, remodeling and injury repair. Genetic mutations that disrupt Gα_s functions cause human disorders with severe skeletal defects, such as fibrous dysplasia of bone and heterotopic bone formation. This chapter focuses on the crucial roles of Gα_s signaling during skeletal development and homeostasis, and the pathological mechanisms underlying skeletal diseases caused by GNAS mutations.

Giant-cell granuloma: 2 case reports

Introduction: Giant-cell granuloma (GCG) is a benign tumor occurring almost exclusively in the jaws. These lesions remain rare but can sometime have an aggressive behavior. In this article, we will describe and follow two cases of GCG. Observations: The first case is a referred female patient, who presents a mandibular swelling. Its clinical and radiological aspects lead us to do a biopsy, with a histological result of GCG. The second case is a patient with a terminal kidney failure, referred for a buccal swelling in the upper left jaw. The cone-beam computed tomography X-ray shows a compartmentalized lesion with blurry limits. An excisional biopsy is performed and the histological diagnosis is a GCG. Discussion: Although the first patient suffers from no systemic disease, the second one presents a terminal kidney failure resulting in a chronic hyperparathyroidism. Hyperparathyroidism can activate osteoclastic resorption and create bone lesions such as brown tumors. Conclusion: The slow and asymptomatic growth of these lesions often result in a late diagnosis. It should be kept in mind as a differential diagnosis when dealing with an osteolytic lesion of the jaws with no clear etiology, especially if hyperparathyroidism or kidney failure is associated.

A novel subchondral bone-grafting procedure for the treatment of giant-cell tumor around the knee: A retrospective study of 27 cases

The vast majority of giant-cell tumors occur around the knee and characteristically affect the subchondral bone. Thermal damage to the articular cartilage arising from the application of polymethylmethacrylate (PMMA) or extensive intralesional curettage presents a challenging problem to orthopedic surgeons and patients due to compliance issues. For this reason, we developed a new subchondral bone-grafting procedure to restore massive bone defects and reduce degenerative changes in the knee.The aim of this study was to describe the novel subchondral bone-grafting procedure and evaluate clinical outcomes in patients with giant-cell tumors around the knee.This retrospective single-center study included a total of 27 patients with giant-cell tumors in the distal femur and proximal tibia admitted to our department from January 2012 to December 2015 and treated with aggressive intralesional curettage. Eleven males and 16 females were included. All cases underwent subchondral autograft bone grafting followed by bone cement reconstruction and instrument internal fixation. The Musculoskeletal Tumor Society (MSTS) score and short form-36 (SF-36) were applied to assess the functional outcome of the knee joint and quality of life. Tumor recurrence, Kellgren and Lawrence (KL) grade, and the distance of the cement to the articular surface were assessed throughout the sample.All cases were followed up after surgery for an average of 32.9 ± 7.1 months (range 25-57 months). At the end of the follow-up period, all patients were alive and free from pulmonary metastasis. Complications associated with this surgery occurred only in 1 patient (3.7%), who presented with an incision infection that resolved with regular dressing and antibiotics. No fractures, instrument breakage, or joint fluid leakage occurred. Local recurrence occurred in 1 case (3.7%) at the distal femur after 23 months and was treated by wide resection followed by prosthesis reconstruction. Twenty-four patients (89%) did not develop radiographic findings of osteoarthritis: at the final follow-up 2 patients (7.4%), had progressed to KL1 and 1 patient had progressed to KL2. According to the MSTS scoring system, the functional score of the affected knee joint at the last follow-up ranged from 80% to 97%, with an average of 87.3%. The quality of life parameters assessed by the SF-36 survey at the last follow-up ranged from 47 to 96, with an average of 77.For patients with giant-cell tumor of bone near the knee, subchondral bone grafting combined with bone cement reconstruction is recommended as a feasible and effective treatment modality.

Custom 3D-printed finger proximal phalanx as salvage of limb function after aggressive recurrence of giant cell tumour

Giant cell tumours (GCT) of the finger phalanges are extremely rare but have a high rate of recurrence. This report details the case of a GCT of the proximal phalanx of the fourth finger in a 64-year-old man. The patient was initially subjected to systemic neoadjuvant denosumab treatment, and subsequent aggressive curettage, sparing of the articular joints, local cryotherapy and autologous intercalary fibular bone graft. Finger function after surgery was considered satisfactory, despite limited proximal interphalangeal (PIP) joint motion. Aggressive local GCT recurrence was noted at the 32-month follow-up, with entire articular and diaphyseal phalangeal destruction. The patient refused amputation and, after analysing several reconstruction options, he was treated by entire en bloc resection and reconstruction employing a 3D-printed custom titanium implant. At the 24-month follow-up, the patient is free of disease and pain, and has a stable finger, good metacarpal-phalangeal joint motion, fusion of the PIP joint, a good Musculoskeletal Tumour Society score, and functional ability.

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

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

Safety and efficacy of denosumab in the treatment of pulmonary metastatic giant cell tumor of bone

Background

Giant cell tumor (GCT) of bone is an intermittent and locally aggressive tumor with increasing pulmonary metastatic potential. In this study, we evaluated the interim clinical outcome of denosumab in patients with pulmonary metastatic GCT.

Materials and methods

We retrospectively reviewed seven patients with pulmonary metastatic GCT who received denosumab treatment after local tumor surgery during January 2014 and July 2016. Denosumab treatment for all patients lasted for at least 12 months. Serial chest computerized tomography scan was used to monitor the drug response and RECIST 1.1 standard was used to evaluate the therapeutic efficacy.

Results

All patients experienced chest pain relief in the first month of treatment. Three patients showed partial response. Four patients got stable disease after denosumab treatment. Adverse events included one patient with hypocalcemia and two patients with fever. No treatment-related deaths were reported. No patient with metastatic disease progression was found during an average of 28.6 months follow-up period.

Conclusion

We presented a promising interim clinical outcome using denosumab to treat patients with pulmonary metastatic GCT. Denosumab might be considered as the first-line treatment for patients with inoperable metastatic pulmonary GCT. However, Phase II clinical study with larger number of patients and longer follow-up period is needed to detect the further efficacy and safety of this drug for lung metastatic GCT.

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

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

Giant Cell Tumor of the Lateral Skull Base: Diagnostic and Management Options

Giant cell tumor of bone (GCTB) is a rare, benign, osteolytic neoplasm that most commonly occurs in early adulthood and often involves the long bones of the body. Although GCTB largely affects the epiphyses of long bones, several reports of GCTB involvement of the cranial and facial bones exist in the literature. In addition to reviewing other reported cases of GCTBs of the lateral skull base in the literature, the authors report here on the clinical presentation, radiographic findings, and neurosurgical management of a patient found to have a GCTB of the middle and infratemporal fossae, which was treated by aggressive en bloc resection of the lateral skull base.

Recommencement of Denosumab for Unresectable Giant Cell Tumor of the Cervical Spine: A Case Report

STUDY DESIGN

A case report.

OBJECTIVE

The aim of this study was to highlight that rapid progression or recurrence of giant cell tumor of the bone (GCTB) can still occur with cessation of Denosumab in the management of unresectable GCTB even in cases with prior demonstration of excellent response to treatment and stable disease over a protracted length of surveillance despite dose reduction. The close proximity of unresectable GCTB to vital structures makes it prudent that we monitor these patients closely given its locally aggressive nature.

SUMMARY OF BACKGROUND DATA

Cervical spine GCTB is extremely rare. Unresectable GCTB has historically been a challenge to treat due to the lack of prospective, randomized clinical trials to guide treatment. Radiotherapy has fallen out of favor due to the risk of malignant transformation, especially as most GCTB patients are young.In recent years, improved understanding of the receptor activator of nuclear factor-κB ligand (RANKL) in the pathophysiology of GCTB has led to the use of Denosumab in patients with recurrent/unresectable/metastatic GCTB and in patients whom surgical resection carries a high morbidity. To date, the optimal dosage and duration of therapy in the treatment of GCTB is unknown.

METHODS

We report a case of cervical spine GCTB in a 53-year-old male with positive surgical margins managed with Denosumab.

RESULTS

This is the first reported case of a cervical spine GCTB managed with Denosumab showing excellent response to treatment, recurrence of disease post cessation of Denosumab despite earlier satisfactory disease control and stabilization achieved even with dose reduction, and again an excellent response with recommencement of the drug.

CONCLUSION

Denosumab is an excellent option in patients with unresectable GCTB or when surgery will result in excessive morbidity. However, further studies are required to determine optimal dosing, treatment duration, side effect profile, and whether Denosumab is truly able to achieve partial or complete disease remission in the long run.

LEVEL OF EVIDENCE

4.

Interventions for managing medication-related osteonecrosis of the jaw

BACKGROUND

Medication-related osteonecrosis of the jaw (MRONJ) is a severe adverse reaction experienced by some individuals to certain medicines commonly used in the treatment of cancer and osteoporosis (e.g. bisphosphonates, denosumab and antiangiogenic agents) and involves the progressive destruction of bone in the mandible or maxilla. Depending on the drug, its dosage, and the duration of exposure, the occurrence of this adverse drug reaction may be rare (e.g. following the oral administration of bisphosphonate or denosumab treatments for osteoporosis, or antiangiogenic agent-targeted cancer treatment) or common (e.g. following intravenous bisphosphonate for cancer treatment). MRONJ is associated with significant morbidity, adversely affects quality of life (QoL), and is challenging to treat.

OBJECTIVES

To assess the effects of interventions versus no treatment, placebo, or an active control for the prophylaxis of MRONJ in people exposed to antiresorptive or antiangiogenic drugs.To assess the effects of non-surgical or surgical interventions (either singly or in combination) versus no treatment, placebo, or an active control for the treatment of people with manifest MRONJ.

SEARCH METHODS

Cochrane Oral Health's Information Specialist searched the following databases: Cochrane Oral Health's Trials Register (to 23 November 2016), the Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library, 2016, Issue 10), MEDLINE Ovid (1946 to 23 November 2016), and Embase Ovid (23 May 2016 to 23 November 2016). The US National Institutes of Health Trials Registry (ClinicalTrials.gov) and the World Health Organization International Clinical Trials Registry Platform were searched for ongoing trials. No restrictions were placed on language or publication status when searching the electronic databases; however, the search of Embase was restricted to the last six months due to the Cochrane Embase Project to identify all clinical trials and add them to CENTRAL.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing one modality of intervention with another for the prevention or treatment of MRONJ. For 'prophylaxis of MRONJ', the primary outcome of interest was the incidence of MRONJ; secondary outcomes were QoL, time-to-event, and rate of complications and side effects of the intervention. For 'treatment of established MRONJ', the primary outcome of interest was healing of MRONJ; secondary outcomes were QoL, recurrence, and rate of complications and side effects of the intervention.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened the search results, extracted the data, and assessed the risk of bias in the included studies. For dichotomous outcomes, we reported the risk ratio (RR) (or rate ratio) and 95% confidence intervals (CI).

MAIN RESULTS

We included five RCTs (1218 participants) in the review. Three trials focused on the prophylaxis of MRONJ. Two trials investigated options for the treatment of established MRONJ. The RCTs included only participants treated with bisphosphonates and, thus, did not cover the entire spectrum of medications associated with MRONJ. Prophylaxis of MRONJOne trial compared standard care with regular dental examinations in three-month intervals and preventive treatments (including antibiotics before dental extractions and the use of techniques for wound closure that avoid exposure and contamination of bone) in men with metastatic prostate cancer treated with zoledronic acid. The intervention seemed to lower the risk of MRONJ: RR 0.10; 95% CI 0.02 to 0.39 (253 participants; low-quality evidence). Secondary outcomes were not evaluated.As dentoalveolar surgery is considered a common predisposing event for developing MRONJ, one trial investigated the effect of plasma rich in growth factors (PRGF) for preventing MRONJ in people with cancer undergoing dental extractions. There was insufficient evidence to support or refute a benefit of PRGF on MRONJ incidence when compared with standard treatment (RR 0.08, 95% CI 0.00 to 1.51; 176 participants; very low-quality evidence). Secondary outcomes were not reported. In another trial comparing wound closure by primary intention with wound closure by secondary intention after dental extractions in people treated with oral bisphosphonates (700 participants), no cases of intraoperative complications or postoperative MRONJ were observed. QoL was not investigated. Treatment of MRONJOne trial analysed hyperbaric oxygen (HBO) treatment used in addition to standard care (antiseptic rinses, antibiotics, and surgery) compared with standard care alone. HBO in addition to standard care did not significantly improve healing from MRONJ compared with standard care alone (at last follow-up: RR 1.56; 95% CI 0.77 to 3.18; 46 participants included in the analysis; very low-quality evidence). QoL data were presented qualitatively as intragroup comparisons; hence, an effect estimate of treatment on QoL was not possible. Other secondary outcomes were not reported.The other RCT found no significant difference between autofluorescence- and tetracycline fluorescence-guided sequestrectomy for the surgical treatment of MRONJ at any timepoint (at one-year follow-up: RR 1.05; 95% CI 0.86 to 1.30; 34 participants included in the analysis; very low-quality evidence). Secondary outcomes were not reported.

AUTHORS' CONCLUSIONS

Prophylaxis of MRONJOne open-label RCT provided some evidence that dental examinations in three-month intervals and preventive treatments may be more effective than standard care for reducing the incidence of MRONJ in individuals taking intravenous bisphosphonates for advanced cancer. We assessed the certainty of the evidence to be low.There is insufficient evidence to either claim or refute a benefit of either of the interventions tested for prophylaxis of MRONJ (i.e. PRGF inserted into the postextraction alveolus during dental extractions, and wound closure by primary or secondary intention after dental extractions). Treatment of MRONJAvailable evidence is insufficient to either claim or refute a benefit for hyperbaric oxygen therapy as an adjunct to conventional therapy. There is also insufficient evidence to draw conclusions about autofluorescence-guided versus tetracycline fluorescence-guided bone surgery.

Improvement of Giant Cell Lesions of the Jaw Treated With High and Low Doses of Denosumab: A Case Series

Giant cell tumors (GCTs) and central giant cell granulomas (CGCGs) are aggressive lesions that appear in the jaw. These lesions occur in the second and third decades of life and often arise in the mandible. Clinical manifestations of these lesions vary from asymptomatic to symptomatic tooth displacement with cortical perforation. GCTs, which are characterized by multinucleated osteoclast-type giant cells that express receptor activator of nuclear factor-κB (RANK) ligand, rarely present in the jaw and have overlapping histopathologic features with CGCGs, which are composed of fibroblastic stromal cell lesions. GCTs and CGCGs have overlying histopathologic features that make distinction between the two challenging. There is a real controversy as to whether giant cell tumors and central giant cell granulomas are in fact, one and the same lesion. The majority of GCTs occur in the long bone, with surgery being the typical therapeutic option. Denosumab as a treatment modality is a fairly new concept that has been used effectively in GCTs affecting long bones. There is less experience, however, with its use for jaw lesions. This seven-case series describes the effective use of both low-dose and high-dose denosumab in the treatment of GCTs and CGCGs affecting the jaw and special dosing considerations for younger patients who present with disease. © 2017 The Authors. JBMR Plus Published by Wiley Periodicals, Inc. on behalf of the American Society for Bone and Mineral Research.

Denosumab: Current Use in the Treatment of Primary Bone Tumors

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