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

Denosumab regimens in the treatment of giant cell tumor of bone: A systematic review with meta-analysis

BACKGROUND

Giant cell tumor of bone (GCTB) is a rare, locally aggressive neoplasm that should be treated surgically, whenever possible. This treatment approach may be linked with greater morbidity besides functional impairment. Denosumab is a human monoclonal antibody. Its administration inhibits bone resorption and has become part of the therapeutic armamentarium against GCTB, as it allows local control with a view to downstaging for a more conservative surgical procedure. However, there is no consensus in the literature regarding the optimal denosumab regimen for GCTB. Therefore, a wide discussion of denosumab regimen is necessary.

AIM

To assess the effectiveness of various therapy protocols employing denosumab in individuals with GCTB.

METHODS

A broad and systematic literature search was carried out using the PRISMA guidelines. We analyzed studies that reported skeletally mature patients with GCTB regardless of sex or ethnicity treated with denosumab. Articles with fewer than five patients and in languages except Spanish, Portuguese and English were excluded. Statistical analysis with proportion meta-analysis was performed due to the dichotomous nature of the data.

RESULTS

1005 articles were screened, of which 26 articles met the inclusion criteria and were selected, totaling 1742 patients, 51.8% women and 48.2% men, with an average of 35 years of age. Treatment with denosumab was associated with high rates of clinical benefit (CB) and imaging response (IR), without changing local recurrence rates when compared to patients treated without denosumab, regardless of the therapeutic regimen adopted and the number of doses applied. The adverse events (AE) presented were mostly mild, with the exception of a malignant transformation to osteosarcoma.

CONCLUSION

Treatment of GCTB with denosumab is effective, showing high rates of CB and IR. The AE that occurred were mostly mild. We found no differences between the articles considering the researched outcomes regardless of the therapeutic regimen adopted.

A Short Course of Preoperative Denosumab Injection Followed by Surgery in High-Risk Giant Cell Tumors of the Extremities: A Retrospective Study

Despite early promising results with denosumab treatment in giant cell tumor of bone (GCTB), recent studies have raised concerns about a high local recurrence rate following preoperative denosumab administration and joint preservation surgery. This retrospective study evaluated data from 25 high-risk GCT patients (Campanacci grade II or III with features like soft tissue extension, pathological fracture, minimal periarticular or subarticular bone) treated with five doses of neoadjuvant denosumab injection followed by either curettage and cementing (n = 13) or joint reconstruction with fibular graft/endoprosthesis (n = 12) between 2014 and 2019. With an average follow-up of 40 months, the study found only one patient of local recurrence. All patients were independently ambulant, with a mean MSTS score of 26.32. Subgroup analysis revealed an MSTS score of 27.76 in the joint preservation group, and 24.75 in the excision with reconstruction/prosthetic replacement group (unpaired t-test, p-value < 0.001). Five patients experienced postoperative complications, including two infections, one recurrence, one mediolateral instability in the prosthetic component, and one restriction of wrist movement. A short course of neoadjuvant denosumab, followed by curettage and cementing or wide excision with joint reconstruction/prosthetic replacement, appears to be an effective strategy for high-risk GCTB patients. This approach not only minimizes surgical morbidity but also does not increase the local recurrence rate. The short course regimen may present a cost-effective and practical option in clinical practice.

Proximal Fibulectomy for Giant Cell Tumours: What Works!

Background

Giant cell tumor of bone (GCTB) is the most common primary tumor of proximal fibula. Because of its close proximity to vascular structures, common peroneal nerve (CPN) and attachment of lateral collateral ligament (LCL), proximal fibulectomy poses unique challenges. We analyzed oncological and functional outcome of patients who underwent proximal fibulectomy for GCTB of proximal fibula.

Material and methods

Between January 2006 and December 2020, 23 patients underwent proximal fibulectomy for GCTB of proximal fibula, four were recurrent tumors. Mean resection length was 9 cm (5 to 15 cm). The LCL and biceps tendon were not reconstructed in 22 cases. The common peroneal nerve was sacrificed in seven patients including three recurrent cases. Functional status was assessed using the Musculoskeletal Tumour Society (MSTS) scoring system.

Results

There were two vascular complications and one infection. With 4 patients lost to follow up, mean follow up was 90 months (12 to 197). No patient had local or distant recurrence. Mean MSTS score was 26 (21 to 30). Eleven of 23 patients (48%) had loss of common peroneal nerve function with poorer functional outcome. No patient had symptoms suggestive of knee instability.

Conclusion

Proximal fibulectomy is oncologically safe. Reconstruction of the LCL attachment is not mandatory and patients do not have symptomatic knee instability. Functional outcomes are compromised after sacrifice of common peroneal nerve and may be potentially improved with tendon transfers at index surgery.

Denosumab combined with microwave ablation excisional scraping for giant cell tumor of the thoracic spine: a case report and literature review

Denosumab has recently become an important part of the treatment regime for spinal giant cell tumors of the bone (GCTB). Its use has significantly reduced the risk of surgery and postoperative complications in patients with spinal GCTB. However, the use of denosumab has not yet been optimized to reap the maximum benefits. Here, we have reported the case of a patient who was treated with denosumab in combination with excision and scraping for GCTB of the T10 vertebrae, which achieved good tumor control and no recurrence at the 2-year postoperative follow-up. We have also reviewed the case in the light of relevant literature as well as presented our ideas and recommendations for the optimal use of denosumab.

The successful control of multiple pulmonary metastasis from giant cell tumor of bone by monthly denosumab administration: A case report

Giant cell tumor of bone (GCTB) is a locally aggressive benign neoplasm that is associated with a large biological spectrum ranging from latent benign to highly recurrent and occasionally metastatic tumor. In this article, we present a case of a 37-year-old woman who presented with fracture at the distal femur due to GCTB. Bone segment resection and reconstruction were done, and histopathology showed tumor features for GCTB. Later, multiple lung metastasis was found 22 months post-operation, which was verified by biopsy. Then systemic denosumab therapy with different intervals (1-month and 2-month) was tried as the treatment. It was clarified that monthly denosumab administration, instead of 2-month interval, was required to control the progression of the unresectable multiple lung metastasis from GCTB, which could be a choice for the future treatment of these patients.

Combined preoperative denosumab and adjuvant microwave ablation for high-risk giant cell tumor of bone: a retrospective study in a single center

BACKGROUND

Giant cell tumor of bone (GCTB) is a locally aggressive neoplasm with a high propensity for recurrence following intralesional curettage. The introduction of denosumab, a RANKL inhibitor, has shown potential in facilitating joint-sparing surgery. However, concerns exist regarding its impact on local recurrence rates. This study aimed to evaluate the efficacy and safety of combined preoperative denosumab with adjuvant microwave ablation (MWA) for the treatment of high-risk GCTB.

METHODS

We conducted a retrospective review of 19 patients with high-risk GCTB who underwent preoperative denosumab treatment followed by curettage and adjuvant MWA. The primary outcome measure was the local recurrence rate, with secondary outcomes including functional status assessed by the Musculoskeletal Tumor Society (MSTS) score and safety profile of the treatment.

RESULTS

In this retrospective analysis, we evaluated the outcomes of 19 patients with high-risk GCTB treated with preoperative denosumab and adjuvant MWA. The median follow-up duration was 33.1 months, 3 patients (15.8%) experienced local recurrence at a median of 21.6 months postoperatively and the local recurrence-free survival was 81.2% at two years. Notably, no patient developed lung metastasis, and all recurrences were successfully managed with repeat curettage and MWA, with a mean MSTS score of 27.3. No patient required joint replacement due to tumor recurrence, resulting in a 100% joint preservation rate.

CONCLUSION

The combination of preoperative denosumab and adjuvant MWA is a feasible and effective strategy for the management of high-risk GCTB, providing effective local control with preserved joint function. This approach may offer a surgical alternative for young patients where joint preservation is paramount.

Immunohistochemical expression of H3.3 G34W in 100 giant cell tumors of bone and its diagnostic mimics, including its value in resolving uncommon diagnostic scenarios: A single institutional study at a tertiary cancer referral center, India

BACKGROUND

There can be a diagnostic challenge in differentiating giant cell tumor of bone (GCTB) from its mimics. Lately, histone H 3 F 3 A (Histone 3.3 ) G34W has been identified as a promising immunohistochemical marker.

AIMS

This study was aimed at evaluating H3.3 G34W immunostaining in 100 GCTBs, including its value in resolving diagnostic dilemmas.

MATERIALS AND METHODS

Immunohistochemical staining for H3.3 G34W was graded in terms of staining intensity (1+ to 3+) and the percentage of tumor cells showing crisp nuclear staining.

RESULTS

One hundred GCTBs occurred in 58 males and 42 females (M: F ratio = 1.3), of 7-66 years age (average = 31.3, median = 28), commonly in distal femur (26), followed by proximal tibia (17), distal radius (12), proximal humerus (7), metacarpals (7), sacrum (6), proximal fibula (6), and relatively unusual sites (19), including a single multicentric case. Out of 92 GCTBs, wherein H3.3 G34W immunostaining worked, 81 (88.1%) showed positive staining in the mononuclear cells, including tumors with fibrous histiocytoma-like areas, sparing osteoclast-like giant cells, with 3+ staining intensity in 65/81 (80%) tumors. All 7/7 (100%) malignant GCTBs showed positive staining, including the pleomorphic/sarcomatous cells. All 7/7 (100%) metastatic GCTBs showed positive immunostaining. Seven out of 10 post-denosumab treated GCTBs showed positive H3.3 G34W immunostaining in the residual mononuclear cells. None of the other 37 "giant cell-rich" lesions displayed H3.3 G34W immunostaining. Four of 9 GCTBs tested for H3.3 G34W mutation showed positive results.

CONCLUSIONS

The diagnostic sensitivity and specificity of H3.3 G34W for GCTB were 88.1% and 100%, respectively. This constitutes one of the first reports from our country, further validating the diagnostic value of H3.3 G34W in differentiating GCTB, including metastatic and malignant forms from its mimics, including small biopsy samples. Its value in various diagnostic dilemmas is presented and utility in identifying residual tumor cells in post-denosumab treated GCTBs is worth exploring.

Reconstruction of the extensor mechanism using polypropylene mesh in a displaced pathological fracture of the patella affected by giant cell tumour

A man in his 30s came to our clinic with a year-long history of progressive pain and swelling in his knee. Diagnostic imaging revealed a displaced patellar fracture with an osteolytic, septated lesion and thinned expanded cortex in both fracture fragments. A core needle biopsy confirmed the diagnosis of giant cell tumour. Treatment involved wide excision of the tumour and the use of polypropylene mesh and a peroneal longus tendon autograft to reconstruct the extensor mechanism of the knee joint. One year postoperatively, the patient experienced no pain, demonstrated full range of motion and showed no signs of functional impairment or local tumour recurrence. This case highlights that reconstruction of the extensor mechanism of the knee after tumour excision with synthetic mesh is an affordable, user-friendly and widely accessible method. It can address large defects effectively while minimising the risks of disease transmission and graft lengthening, resulting in satisfactory outcomes.

Management of a rare mandibular giant cell tumor of bone by neoadjuvant denosumab therapy and surgery: A 4-year follow-up case report

INTRODUCTION

Giant cell tumor of bone (GCTB) is a very rare tumor encountered in the jaws and its histology is quite similar to the more common giant cell granuloma of the jaws (GCGJ). These two entities can be easily confused in maxillofacial region. They are classically managed surgically, but in some localizations and in specific medical-surgical contexts, neoadjuvant therapy with denosumab may be indicated. This report tends to reinforce existing evidence in favor of the use of a neoadjuvant approach, particularly for localization of GCTB in the orofacial region.

PRESENTATION OF CASE

This is a 57-year-old female patient, an alcoholic smoker, in whom a voluminous mandibular radiolucent lesion was discovered during a routine X-ray by her dentist. After medical imaging assessment and incisional biopsy, diagnosis of GCTB was established. A neoadjuvant denosumab therapy was proposed first followed by a secondary surgical curettage. After 4 years' follow-up, complete healing was observed with no recurrence of the lesion.

DISCUSSION

Surgical management of aggressive GCTB is risky particularly in localizations involving the sacrum, spine or craniofacial skeleton with a high residual recurrence rate. The use of denosumab to stop tumor progression and facilitate secondary excision surgery is a recent approach that is now well documented in the literature showing promising results with a low rate of side effects.

CONCLUSION

This case of mandibular GCTB is to our knowledge the unique case described in this localization and treated by denosumab neoadjuvant therapy followed by surgery with a 4-year follow-up showing a complete healing.

Utility of immunohistochemical expression of H3.3K36M and DOG1 in the diagnosis of chondroblastomas: An experience from a tertiary cancer referral center

Despite its characteristic clinicopathological features, chondroblastoma may pose a diagnostic challenge, given its morphological spectrum, potential for subdiagnostic appearances in limited biopsy specimens, and its potential mimicry of other entities. Recently, a characteristic H3F3B mutation underlying most chondroblastomas was described, which led to the identification of H3.3K36M as the corresponding diagnostic immunohistochemical marker. The present study is an evaluation of immunohistochemical features of 26 chondroblastomas, including DOG1 and H3.3K36M immunostaining. H3.3K36M immunostaining was graded as 1+, 2+ and 3+ in terms of staining intensity. There were 17 males and 9 females (M:F = 1.8:1) with ages ranging from 7 to 34 years (average = 16.7, median = 16). The most common location was proximal humerus (8, 30.7 %) followed by proximal tibia (5, 19.2 %), distal femur (3, 11.5 %), proximal femur (3, 11.5 %), pelvis (2,), followed by distal tibia, calcaneum, upper sternum, scapula, and D9 vertebra, in a single case, respectively. Eighteen (69.23 %) tumors displayed all the classic histopathological features. Immunohistochemically, the tumor cells were positive for S-100 P (19/22, 86.3 %), DOG1 (focal to patchy) (21/23 91.3 %), and H3.3K36M (26/26, 100 %). H3.3K36M tested in other tumors, constituting diagnostic mimics of a chondroblastoma, such as giant cell tumor of bone, chondromyxoid fibroma, and tenosynovial giant cell tumors, showed negative staining. Six tumors, initially diagnosed as chondroblastomas were reclassified into other entities with the help of negative H3.3K36M immunostaining. The present study reinforces H3.3K36M as a highly sensitive and specific marker for diagnosing chondroblastoma, including small biopsies, and in uncommon tumor sites with variable histopathological features. DOG1 is also useful in reinforcing a diagnosis of chondroblastoma in a clinicoradiological context, especially in laboratories lacking H3.3K36M immunostain. However, its staining pattern is variable.

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

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

A novel technique of reconstruction of the distal tibia using allograft after resection of giant cell tumor: A case report with literature review

Giant cell tumor (GCT) of the distal tibia can result in significant bone loss and soft tissue compromise, which can present a challenge for reconstruction. Various techniques have been described for the reconstruction of large defects, including the use of allografts. In this article, we describe a novel technique of reconstruction of a large defect in the distal tibia using two femoral head allografts after resection of GCT. The technique involves using two femoral head allografts, which are shaped to fit the defect and secured with a locking plate and screws. Using this technique, we present a case report of a patient with GCT of the distal tibia who underwent resection and reconstruction. At the 18-month follow-up, the patient had good functional outcomes and no evidence of tumor recurrence. This technique offers a viable option for reconstructing large defects in the distal tibia after GCT resection, particularly in cases where autograft is not available or not feasible. Further studies are needed to evaluate the long-term outcomes and complications associated with this technique.

Case Report: Unresectable pulmonary metastases of a giant cell tumor of bone treated with denosumab: a case report and review of literature

Giant cell tumors of bone (GCTB) sometimes metastasize to distant organs. In this case report, we present pulmonary metastases of GCTB mimicking malignancies. A 49-year-old man underwent two surgical treatments for a GCTB of the right proximal radius. At the time of the second surgery, no lesions were observed on chest radiography. Three years after surgery, the patient presented with cough and dyspnea, and chest radiography and computed tomography (CT) revealed multiple lung nodules. Positron emission tomography/CT revealed a high accumulation of 18F-fluoro-2-deoxy-D-glucose (18F-FDG) in multiple lesions. Based on the rapid growth and accumulation of 18F-FDG, a metastatic malignant tumor was suspected. CT-guided needle biopsy was performed, and the histology showed proliferation of spindle cells and multinuclear giant cells without malignant changes. Denosumab was administered because multiple lung lesions were unresectable. One month after denosumab treatment, CT showed marked shrinkage of the lesions, and the symptoms significantly improved. Eighteen months after the initial treatment with denosumab, the patient had no symptoms or tumor growth. Although its long-term efficacy and safety remain unclear, denosumab may be a treatment option for patients with unresectable pulmonary GCTB.

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.

Surgical challenges, novel techniques, and systemic treatment of giant cell tumour of bone of the distal radius

Aims

Giant cell tumour of bone (GCTB) treatment changed since the introduction of denosumab from purely surgical towards a multidisciplinary approach, with recent concerns of higher recurrence rates after denosumab. We evaluated oncological, surgical, and functional outcomes for distal radius GCTB, with a critically appraised systematic literature review.

Methods

We included 76 patients with distal radius GCTB in three sarcoma centres (1990 to 2019). Median follow-up was 8.8 years (2 to 23). Seven patients underwent curettage, 38 curettage with adjuvants, and 31 resection; 20 had denosumab.

Results

Recurrence rate was 71% (5/7) after curettage, 32% (12/38) after curettage with adjuvants, and 6% (2/31) after resection. Median time to recurrence was 17 months (4 to 77). Recurrences were treated with curettage with adjuvants (11), resection (six), or curettage (two). Overall, 84% (38/45) was cured after one to thee intralesional procedures. Seven patients had 12 months neoadjuvant denosumab (5 to 15) and sixmonths adjuvant denosumab; two recurred (29%). Twelve patients had six months neoadjuvant denosumab (4 to 10); five recurred (42%). Two had pulmonary metastases (2.6%), both stable after denosumab. Complication rate was 18% (14/76, with 11 requiring surgery). At follow-up, median MusculoSkeletal Tumour Society score was 28 (18 to 30), median Short Form-36 Health Survey was 86 (41 to 95), and median Disability of Arm, Shoulder, and Hand was 7.8 (0 to 58).

Conclusion

Distal radius GCTB treatment might deviate from general GCTB treatment because of complexity of wrist anatomy and function. Novel insights on surgical treatment are presented in this multicentre study and systematic review. Intralesional surgery resulted in high recurrence-rate for distal radius GCTB, also with additional denosumab. The large majority of patients however, were cured after repeated curettage. Cite this article: Bone Jt Open 2022;3(7):515–528.

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.

Denosumab in Giant Cell Tumor of Bone: Multidisciplinary Medical Management Based on Pathophysiological Mechanisms and Real-World Evidence

Simple Summary

The widely accepted local therapy in extremity giant cell tumor of bone (GCTB) is surgery, in the form of extended intralesional curettage with adequate disease clearance and retention of the limb, wherever possible. Denosumab is a relevant therapy option for advanced GCTB, to benefit tumor response and surgical down-staging. Most GCTB patients with localized disease can be successfully treated with surgical curettage; patients with primary unresectable lesions or metastases may experience long-term clinical and radiological remission and pain control with denosumab treatment, and in this clinical situation, denosumab is currently the treatment of choice.

Abstract

(1) Despite the benign nature of the giant cell tumor of bone (GCTB), it shows a local recurrence rate of up to 50% and a chance of malignant transformation. The widely accepted local therapy in extremity GCTB is surgery, in the form of extended intralesional curettage with adequate disease clearance and retention of the limb, wherever possible. Denosumab, a human monoclonal antibody directed against the RANKL and associated inhibition of the RANKL pathway, is a relevant therapy option for advanced GCTB, to benefit tumor response and surgical down-staging. (2) The literature review of patients with GCTB treated with denosumab is performed via PubMed, using suitable keywords from January 2009 to January 2021. (3) Current indications for denosumab use are not definitively clear and unambiguous. Most GCTB patients with localized disease can be successfully treated with surgical curettage, and the role of denosumab in preoperative therapy in this patient population remains unclear. (4) However, patients with primary unresectable lesions or metastases may experience long-term clinical and radiological remission and pain control with denosumab treatment, and in this clinical situation, denosumab is currently the treatment of choice.

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.

Study of imaging changes following preoperative denosumab for giant cell tumor of bone

•

The preoperative application of denosumab can reduce tumor blood supply.

•

The decrease of blood supply was the most significant in the initial stage of treatment.

•

It is not recommended to apply denosumab long before surgical treatment.

Background

The changes in the characteristics of the tumor blood supply of giant cell tumor of bone over time after treatment with denosumab remain unclear. The purpose of this study was to evaluate the change in the blood supply imaging characteristics of giant cell tumor of bone after preoperative denosumab treatment and to provide evidence for evaluating the reasonable time for preoperative treatment.

Methods

A total of 59 patients with giant cell tumor of bone who were treated in our hospital from 2014 to 2019 were enrolled in the study. All patients underwent enhanced CT examination of the tumor site before denosumab treatment and every month after treatment. The plain CT value and enhanced CT value of the tumor were measured, and the CT enhancement rate of the tumor was calculated. The change in the CT enhancement rate of the tumor over time after denosumab treatment was analyzed.

Results

The average tumor enhancement rates were 2.14 (1.22–4.05), 1.60 (1.12–2.53), 1.38 (1.02–2.24), and 1.25 (1–2.11) before denosumab treatment and one month, three months, and six months after treatment, respectively. After denosumab treatment, the average monthly CT enhancement rate decreased as follows: 0.54 (25.2%) in the first month, 0.11 (5.15%) in the second to third months, and 0.04 (1.87%) in the fourth to sixth months. The tumor enhancement rate was no longer significantly reduced three months post-treatment. There was a significant correlation between the reduction in the CT enhancement rate and the initial CT enhancement rate (P = 0.000).

Conclusion

The preoperative application of denosumab can reduce tumor blood supply. The decrease in the blood supply is the most significant in the initial stage of treatment. Following treatment, the decrease in the blood supply gradually reduces over time. Therefore, for the purpose of reducing intra-operative bleeding and facilitating surgery, application of denosumab treatment is not recommended more than three months before surgery.

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

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

Metastasectomy Versus Non-Metastasectomy for Giant Cell Tumor of Bone Lung Metastases

Approximately 2% to 9% of giant cell tumor of bone (GCTB) metastasizes systemically, mainly to the lungs. The biological behaviors and clinical courses of lung metastases are difficult to predict, and their treatment recommendations vary, including metastasectomy and non-metastasectomy with chemotherapy (denosumab, interferon-alfa, bisphosphonates), with radiation therapy, or with observation alone. However, it is unclear whether metastasectomy for GCTB lung metastases decreases the mortality rate of these patients. Therefore, the authors performed this systematic review to compare metastasectomy and non-metastasectomy for GCTB patients with operable lung metastasis. Of the 919 relevant studies, 16 studies (138 patients) were included for analysis; 61.6% of patients had metastasectomy and 38.4% had non-metastasectomy. Analysis showed that mortality rates were similar for the patients who had metastasectomy compared with those who did not; the proportion of patients who died of disease was 7.1% in the metastasectomy group and 17.0% in the non-metastasectomy group, with an overall pooled odds ratio of 0.64 (P=.36). Therefore, physicians should reconsider the potential risks and benefits of metastasectomy for patients with GCTB and lung metastasis, because metastasectomy does not reduce the mortality rate in these patients. [Orthopedics. 2021;44(6):e707-e712.].

Comparison of Denosumab and Zoledronic acid as neoadjuvant therapy in patients with giant cell tumor of bone

OBJECTIVES

Both Zoledronic acid and denosumab have been utilized in neo-adjuvant setting for facilitating surgery and downsizing the lesion in Giant cell tumor (GCT). This study is aimed at comparing Zoledronic acid and Denosumab, when used in neo-adjuvant setting, in terms of radiological and clinical outcomes in GCT undergoing surgical intervention.

PATIENTS AND METHODS

Patients undergoing surgical intervention for GCT who received either denosumab or Zoledronic acid as neoadjuvant agents were retrospectively analyzed for reduction in tumor load radiologically, change in surgical plan after therapy, facilitation of surgery, therapy related complications, cost of treatment, rate of local recurrence and clinical outcomes.

RESULTS

Twenty patients received denosumab and 19 patients received Zoledronic acid as neoadjuvant agent. There was no significant difference in radiological outcomes, facilitation of surgery and clinical outcomes at end of follow-up. Zoledronic acid group had lower number of recurrences, however, not statistically significant. Therapy with Zoledronic acid was significantly cheaper (p = 0.001).

CONCLUSION

Zoledronic acid is a cheaper alternative to denosumab in terms of solidification of lesion, reducing recurrence rates and improving clinical outcomes. Larger prospective studies required to further delineate this outcome with Zoledronic acid.

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.

Role of denosumab before resection and reconstruction in giant cell tumors of bone: a single-centered retrospective cohort study

BACKGROUND

Denosumab has been approved by Food and Drug Authority in 2013 for use in surgically unresectable Giant cell tumor (GCT) to achieve resectable tumor margins. The aim of this study is to investigate the functional outcome and surgical convenience with the use of neoadjuvant denosumab before resection and reconstruction in Campanacci grade III GCT.

METHODS

We retrospectively reviewed 70 cases of Campanacci grade III GCT receiving resection and reconstruction between January 2014 and December 2019. They were stratified into two groups: one group of 29 patients received once-weekly denosumab 120 mg for 4-weeks before resection and reconstruction, while the other group of 41 patients did not receive denosumab before resection and reconstruction. Quality of life by musculoskeletal tumor society score where 0-7 means poor, 8-14 means fair, 15-22 means good; above 22 means excellent, incidence of tumor recurrence, intraoperative duration in minutes and postoperative positive margins were assessed for each cohort after 12 months follow-up.

RESULTS

There was no significant difference in musculoskeletal tumor society score (25.75 vs. 27.41; P  = 0.178), incidence of recurrence (3.45% vs. 4.88%; P  < 0.001), and postoperative positive margins (10.34% vs. 4.88%; P  = 0.38) for both groups. However, the intraoperative duration (133.38 vs. 194.49; P  < 0.001) was significantly higher in the non-denosumab group compared with denosumab group.

CONCLUSIONS

Neoadjuvant denosumab is equally effective considering postoperative functional outcomes and surgical convenience except intraoperative duration where it is highly helpful in saving the operating time duration. Easier identification, resection and lesser reconstruction are the key surgical convenience offered by neoadjuvant denosumab.

Denosumab for Effective Tumor Size Reduction in Patients With Giant Cell Tumors of the Bone: A Systematic Review and Meta-Analysis

BACKGROUND

Denosumab is a human monoclonal antibody that has been used successfully in the treatment of giant cell tumors of bone. These tumors are rare and, in principle, benign, but they are highly aggressive, locally advanced, osteolytic bone tumors that can metastasize to the lungs. Denosumab is an effective treatment when these tumors cannot be surgically removed or when surgical resection is likely to lead to severe morbidity (eg, loss of limbs or joints). The aim of this systematic review and meta-analysis was to investigate patients with giant cell tumors of bone who experienced tumor progression during treatment with denosumab and to compare them with patients who experienced reduction of their giant cell tumors of bone during treatment with denosumab.

METHODS

Embase, Cochrane Library, and MEDLINE/PubMed databases were searched for trials submitted by January 7, 2020, that reported the efficacy and safety of denosumab in patients with giant cell tumors of bone.

RESULTS

Sixty studies were reviewed, involving a total of 1074 patients who had giant cell tumors of bone and were treated with denosumab. Of the 60 studies, 58% of the patients were from case series studies, 39% from open-label phase II studies, and 3% from case reports. The response rate for denosumab as a treatment for giant cell tumors of bone was 97.5%, with statistical significance (P < .0001). Pain in the limbs was statistically the most common adverse event for denosumab treatment in case series studies (P < .0001). No treatment-related deaths occurred in the reviewed studies.

CONCLUSION

Cumulative evidence supports the addition of surgery to optimal medical therapy with denosumab to reduce tumor size, clinical symptoms, and mortality among patients with giant cell tumors of bone.

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.

Outcome of lung metastases due to bone giant cell tumor initially managed with observation

Background

The outcomes of patients with lung metastases from giant cell tumor of bone (GCTB) vary from spontaneous regression to uncontrolled growth. To investigate whether observation is an appropriate first-line management approach for patients with lung metastases from GCTB, we evaluated the outcomes of patients who were initially managed by observation.

Methods

We retrospectively reviewed the data of 22 patients with lung metastases from histologically confirmed GCTB who received observation as a first-line treatment approach. The median follow-up period was 116 months.

Results

Disease progression occurred in 12 patients (54.5%). The median interval between the discovery of lung metastases and progression was 8 months. Eight patients underwent metastasectomy following initial observation. The median interval between the discovery of lung metastases and treatment by metastasectomy was 13.5 months. None of the patients experienced spontaneous regression. Of the 22 patients, 36.4% needed a metastasectomy, and 9.1% required denosumab treatment during the course of the follow-up period. Disease progression occurred in 45.5% of the 11 patients with lung nodules ≤ 5 mm, while all five of the patients with lung nodules > 5 mm experienced disease progression. Progression-free survival was significantly worse in the group with lung nodules > 5 mm compared to the group with lung nodules ≤ 5 mm (p = 0.022).

Conclusions

Observation is a safe first-line method of managing patients with lung metastases from GCTB. According to radiological imaging, approximately half of the patients progressed, and approximately half required a metastasectomy or denosumab treatment. However, patients with lung nodules > 5 mm should receive careful observation because of the high rate of disease progression in this group.

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.

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.

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.

The impact of curettage technique on local control in giant cell tumour of bone

INTRODUCTION

Although consensus has been reached regarding the main aspects of intralesional surgery for giant cell tumour of the bone (GCTB), debates continue about the most effective combination of local adjuvants. The purpose of study was to analyze the previous experience and determine the most effective curettage approach for GCTB.

METHODS

We summarized the findings from 89 papers published from 1962 to 2020 related to this subject. Database consisted of 137 treated groups that included 6441 patients who underwent different curettage techniques without pre-operative administration of bisphosphonates or RANKL inhibitors.

RESULTS

Recurrence rates after simple curettage ranged between 27 and 82% with a median value at 47%. The use of one or two local adjuvants reduced the incidence of recurrences approximately by 50% when compared with simple curettage. High-speed burring combined with chemical adjuvants or followed by poly(methyl methacrylate) cementation with or without bone grafting further improved the local control leading to good and excellent results; however, these were not documented in all studies. Simultaneous use of burring, chemical adjuvants, and cementation, which we named here as combined curettage, allowed to down local relapses to the range of 0-26%, with a median at 11%. Oncologic outcomes after combined curettage are significantly better when compared with simple curettage (p < 0.0001) and other variants of enhancement (p = 0.001).

CONCLUSIONS

Combined curettage appears to provide the most potent and comprehensive impact on residual tumour cells located in risk zones. This approach should be considered for locally advanced tumours when function-preserving surgery is planned. Additional comparative studies are required to define the optimal curettage enhancement for each individual patient.

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.

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.].

Role of (Neo)adjuvant Denosumab for Giant Cell Tumor of Bone

OPINION STATEMENT

Denosumab is a RANK ligand inhibitor approved for the treatment of giant cell tumor of bone. While the role of denosumab in the setting of advanced and unresectable disease is well established, its role in surgically resectable disease is currently under discussion. Several prospective and retrospective series on neoadjuvant therapy in potentially resectable tumor with high morbidity surgery reported a relapse rate of 10-20% after resection and 30-40% after curettage. At the same time, less morbid surgery has obvious clinical advantages for the patient, and several studies have shown the efficacy of denosumab in downgrading of the surgical procedure. Currently, the role of neoadjuvant denosumab in operable GCTB is limited to selected cases in which a diffuse reactive bone formation and peripheral ossification can make an easier surgical procedure, for example, in tumors with a large soft tissue component. A planned resection may become less morbid when preoperative denosumab is administered. Whenever a segmental resection is thought to be indicated at diagnosis, denosumab may be considered in the neoadjuvant setting. A preoperative course of 6 months is considered safe and effective. Two case scenarios are presented and critically discussed. Because of the high recurrence rates after denosumab treatment followed by curettage, we discourage the use of denosumab when curettage is considered feasible. In this setting, a short course of preoperative denosumab (2-6 months) may be considered for highly selected cases, for example in pathological fractures. The role of adjuvant denosumab needs further investigation. Long-term disease control has been reported in case of non-surgical lesions, even after treatment interruption, but there is no consensus on ideal treatment duration and dosage for these scenarios. In all cases, multidisciplinary discussion with oncology, pathologist, radiologist, and surgeons is mandatory. Patient's comorbidities, dental conditions, and preferences, including family planning, should always be taken into account.

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

BACKGROUND

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

QUESTIONS/PURPOSES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

Immunohistochemical analysis of 36 cases of chondroblastomas: A single institutional experience

Chondroblastoma is a relatively uncommon, primary benign bone tumor, frequently identified in young individuals. Despite its classical radiologic and histopathological features, at times, it is fraught with a diagnostic challenge, especially differentiating it from a giant cell tumor of bone (GCTB); an osteosarcoma and a chondrosarcoma. Lately, few studies have shown the diagnostic utility of immunohistochemical (IHC) expression DOG1 antibody in chondroblastomas. The present study was undertaken to evaluate IHC expression of S100 protein, DOG1 and p63 in 36 chondroblastomas. From January 2013 to July 2019 (6-year duration), 106 chondroblastomas were diagnosed, with IHC staining performed in 36 cases. Conventional Hematoxylin and Eosin stained microsections and IHC stained sections were reviewed in 36 cases. IHC staining of p63 (intranuclear), S100 protein (nuclear and cytoplasmic) and DOG1 (cytoplasmic membranous) was recorded in various cases. Seventy-four tumors occurred in males and 32 in females, within age-range of 7-55 years (average = 18.6), frequently in tibia (33/106; 31.1%), followed by femur (26, 24.5%) humerus (22, 20.7%), calcaneum (5) and scapula (4). IHC staining for S100P was positive in 33/36cases (91.7%); DOG1 in 16/19 (84.2%) cases and p63 in 10/15cases (66.6%). DOG1 immunostaining was negative in 25 various other tumors. Sensitivity and specificity for S100P, DOG1and p63 in chondroblastomas was (91.6%, 59.3%); (84.2%, 100%) and (66.6%, 46.6%), respectively. P63 was positively expressed in 15/27 (55.5%) GCTBs. S100 protein and DOG1 can be utilized for a confirmatory diagnosis of a chondroblastoma, especially for differentiating it from its other differentials, such as GCTB, in view of certain associated therapeutic implications. P63 is not useful in that scenario.

Short-term Preoperative Denosumab With Surgery in Unresectable or Recurrent Giant Cell Tumor of Bone

Objective

The purpose of this retrospective study was to evaluate the clinical and oncological results of combination treatment of short‐term preoperative denosumab (the receptor activator of nuclear factor kappa‐B ligand inhibitor) with surgery in unresectable or recurrent cases of giant cell tumor of the bone (GCTB).

Methods

Between 2016 and 2018, 11 eligible patients (1 man, 10 women, mean age 38.1 years) with grade 3 GCTB were treated with a combination of short‐term (six doses) preoperative denosumab and surgery in a single institution. The clinical, radiological, and pathological alteration after the denosumab treatment were compared. The oncological results of the combination therapy were also recorded. Meanwhile, adverse effects or complications of denosumab, if any, were reported.

Results

The median follow‐up time after surgical procedure was 30 months (range 13–45 months). After 3–4 denosumab injections, pain relief was observed in all patients. In two spine patients, the neurological status improved after four doses of treatment. Intraoperatively, the margin of the tumor became clear and the intensity of the tumor increased while the blood supply around and within the lesion decreased. Within the lesion, the typically soft and loose tissue were replaced by the tough and dense fibro‐osseous tissue. The mean diameter of the lesion before and after treatment was 61.55 ± 22.49 mm and 51.81 ± 21.12 mm, respectively, and the T‐score was 1.02 (P = 0.32). Variable calcification was observed at the periphery and within the lesion. A total of three patients experienced local recurrence in this study. In the resection group, only one extremity patient had soft tissue recurrence that was treated with en‐bloc excision. In the curettage group, two of three sacral tumor patients had local occurrence. Both refused re‐operation and restarted the monthly denosumab injection thereafter, and the lesions remained stable at the final follow up. Finally, no adverse effects or complications related to denosumab treatment were found.

Conclusion

For the unresectable or recurrent GCTB cases, short‐term (six doses) preoperative use of denosumab improved clinical symptoms, decreased the tumor size, and increased the tumor density. The changes in tumors, in turn, simplified the tumor removal manipulation and, subsequently, decreased the local recurrence for the resection surgery. For the curettage, the denosumab‐induced changes had mixed impacts, and shorter term (fewer than six doses) usage may be more appropriate. Our six‐dose regime was deemed safe, while the safety of long‐term use remains unknown.

Outcomes of short segment distal radius resections and wrist fusion with iliac crest bone grafting for giant cell tumor

BACKGROUND

Distal radius is third most common site for occurrence of Giant cell tumor (GCT) of bone. Most of Campanacci grade II & III cases require resection. Reconstructions of these defect are challenging. Though fibular arthroplasty provides mobility at wrist but is fraught with complications of donor site morbidity and instability with wrist pain. Wrist arthrodesis with ulna translocation provides stable reconstruction but is cosmetically less appealing. We present a series of 12 cases of GCT of distal radius treated with short segment (6 cm or less) resections and wrist fusion with iliac crest grafting. We evaluated donor site morbidity, functional and oncological outcomes.

OBJECTIVES

To assess time to union, donor site morbidity, functional and oncological outcomes after wrist fusion with iliac crest bone grafting for distal radius resection (≤6 cm).

METHODS

Retrospective analysis was performed from a prospectively maintained database between January 2011 and December 2017, 12 patients (7 male and 5 female; 9 primary and 3 recurrent; all Campanacci grade III) were included. Mean age was 29 years (15-41 years) with mean resection length of 5.1 cm (4.5-6 cm). The dominant hand was involved in 6 patients. Time to union, donor site morbidity, functional and oncologiacal outcomes were evaluated. Functional outcomes were evaluated using Musculo-Skeletal Tumor Society (MSTS) score and Patient Rated Wrist Evaluation (PRWE) score. Grip strength and arc of forearm rotation were also evaluated.

RESULTS

All patients were available for analysis. No symptomatic donor site morbidity was observed. One patient had prominent implant following a fall and delayed union. Mean time to union for 22 osteotomy sites in rest of 11 patients (both proximal and distal) was 6 months (4-11 months). At median follow up of 45 months (18-78 months) 2 patients had soft tissue recurrence, 1 had a stable pulmonary metastasis. Local Recurrence rate was 17%. All patients returned to their pre surgery activity. Mean MSTS score was 25 (19-29) and PRWE score was 12 (6-28). Grip strength and Prono - supination measurements were available in 10 patients. Grip strength was 69% of non operated limb. Mean supination was 53° (0° to 80°) and mean protonation was 73° (40° to 80°). Mean arc of rotation was 126° (80° to 160°).

CONCLUSION

Reconstruction of distal radius bone defects with Iliac crest bone grafting and wrist arthrodesis retains prono-supination while maintaining wrist girth (cosmesis). The oncologic and functional outcomes make it an acceptable modality in selected cases of distal radius tumours with short resection length (≤6 cm).