Clinical characteristics and risk factors analysis of lung metastasis of benign giant cell tumor of bone

Giant cell tumor of bone and secondary osteoarthritis

Giant cell tumor of bone is a commonly encountered aggressive epiphyseal bone tumor, most often treated surgically. The natural history and presentation are classically described but the histopathology is poorly understood. Intralesional curettage is the mainstay of treatment, but there is significant variation in the use of adjuvant and cavity filling modalities. No gold standard has been agreed upon for treatment, and a variety of techniques are currently in use. Given its location, secondary osteoarthritis is a known long-term complication. This review examines the natural history of giant cell tumors, treatment options and complications, and subsequent development of osteoarthritis. Arthroplasty is usually indicated for secondary osteoarthritis although data is limited on its efficacy. Further directions will likely center on improved pharmacological treatments as well as improved arthroplasty techniques.

Establishment and characterization of two novel patient-derived cell lines from giant cell tumor of bone: NCC-GCTB8-C1 and NCC-GCTB9-C1

Giant cell tumor of bone (GCTB) is a rare osteolytic bone tumor consisting of mononuclear stromal cells, macrophages, and osteoclast-like giant cells. Although GCTB predominantly exhibits benign behavior, the tumor carries a significant risk of high local recurrence. Furthermore, GCTB can occasionally undergo malignant transformation and distal metastasis, making it potentially fatal. The standard treatment is complete surgical resection; nonetheless, an optimal treatment strategy for advanced GCTB remains unestablished, necessitating expanded preclinical research to identify appropriate therapeutic options. However, only one GCTB cell line is publicly available from a cell bank for research use worldwide. The present study reports the establishment of two novel cell lines, NCC-GCTB8-C1 and NCC-GCTB9-C1, derived from the primary tumor tissues of two patients with GCTB. Both cell lines maintained the hallmark mutation in the H3-3A gene, which is associated with tumor formation and development in GCTB. Characterization of these cell lines revealed their steady growth, spheroid-formation capability, and invasive traits. Potential therapeutic agents were identified via extensive drug screening of the two cell lines and seven previously established GCTB cell lines. Among the 214 antitumor agents tested, romidepsin, a histone deacetylase inhibitor, and mitoxantrone, a topoisomerase inhibitor, were identified as potential therapeutic agents against GCTB. Conclusively, the establishment of NCC-GCTB8-C1 and NCC-GCTB9-C1 provides novel and crucial resources that are expected to advance GCTB research and potentially revolutionize treatment strategies.

The Evaluation and Management of Lung Metastases in Patients with Giant Cell Tumors of Bone in the Denosumab Era

Giant cell tumor of bone (GCTB) is characterized by uncertain biological behavior due to its local aggressiveness and metastasizing potential. In this study, we conducted a meta-analysis of the contemporary literature to evaluate all management strategies for GCTB metastases. A combination of the terms "lung metastases", "giant cell tumor", "bone", "treatment", and "oncologic outcomes" returned 133 patients meeting our inclusion criteria: 64 males and 69 females, with a median age of 28 years (7-63), at the onset of primary GCTB. Lung metastases typically occur at a mean interval of 26 months (range: 0-143 months) after treatment of the primary site, commonly presenting as multiple and bilateral lesions. Various treatment approaches, including surgery, chemotherapy, radiotherapy, and drug administration, were employed, while 35 patients underwent routine monitoring only. Upon a mean follow-up of about 7 years (range: 1-32 years), 90% of patients were found to be alive, while 10% had died. Death occurred in 25% of patients who had chemotherapy, whereas 96% of those not treated or treated with Denosumab alone were alive at a mean follow-up of 6 years (range: 1-19 years). Given the typically favorable prognosis of lung metastases in patients with GCTB, additional interventions beyond a histological diagnosis confirmation may not be needed. Denosumab, by reducing the progression of the disease, can play a pivotal role in averting or delaying lung failure.

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

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

Conjoined Free Fibula Transplantation and First Carpometacarpal Joint Prosthesis for Functional Thumb Reconstruction-A Case Report

BACKGROUND

Giant cell tumors grow locally invasive with osseous and soft tissue destruction, requiring wide resection to avoid recurrence. Stable reconstruction of the first carpometacarpal (CMC-1) joint remains a challenge due to its high range of mobility. The latter is of paramount for the functionality of the hand.

PURPOSE

Therefore, the aim of this study was to report our approach for a combined reconstruction of the first metacarpal and the CMC-1 joint.

METHODS

A 58-year-old woman underwent wide resection of a benign giant cell tumor at the base and shaft of the first metacarpal of the left thumb. Because of the loss of the CMC-1 joint and the instability of the thumb, an osseous reconstruction using a vascularized fibular graft combined with a TOUCH Dual Mobility CMC-1 prosthesis was performed to reconstruct the CMC-1 joint.

RESULTS

Osseous healing was observed after 3 months. No tumor recurrence and good joint function were documented at the follow-up investigation after 1 year. The patient reported only minor restrictions during activities of daily living. Thumb opposition was possible with a Kapandji score of 8/10. A slight pain while walking remained as a donor-side morbidity at the right lower leg.

CONCLUSION

Metacarpal reconstruction with vascularized fibula bone grafts allowed a combined joint reconstruction with a commercially available prosthesis, which is an approach to restore the complex range of motion of the thumb.

Management of giant cell tumors of the distal radius

Background

The distal radius is the most common location for giant cell tumors (GCT) in the upper extremity. Treatment should balance the goals of maximizing function and minimizing recurrence and other complications. Given the complexity in surgical treatment, various techniques have been described without clear standards of treatment.

Objectives

The purpose of this review is to provide an overview of evaluation of patients presenting with GCT of the distal radius, discuss management, and provide an updated summary on outcomes of treatment options.

Conclusion

Surgical treatment should consider tumor Grade, involvement of the articular surface, and patient-specific factors. Options include intralesional curettage and en bloc resection with reconstruction. Within reconstruction techniques, radiocarpal joint preserving and sparing procedures can be considered. Campanacci Grade 1 tumors can be successfully treated with joint preserving procedures, whereas for Campanacci Grade 3 tumors consideration should be given to joint resection to prevent recurrence. Treatment of Campanacci Grade 2 tumors is debated in the literature. Intralesional curettage and adjuvants can successfully treat cases where the articular surface can be preserved, while en-bloc resection should be used in cases where the articular surface cannot undergo aggressive curettage. A variety of reconstructive techniques are used for cases needing resection, with no clear gold standard. Joint sparing procedures preserve motion at the wrist joint, whereas joint sacrificing procedures preserve grip strength. Choice of reconstructive procedure should be made based on patient-specific factors, considering relative functional outcomes, complications, and recurrence rates.

Comparing clinical outcomes between extended curettage and wide resection in Enneking stage 3 giant cell tumor of bone

PURPOSE

Our objectives were (1) to compare the recurrence, metastases, and complication rates of patients with Enneking stage 3 GCTB who underwent extended curettage vs wide resection and (2) examine the factors which might influence surgical options for each patient.

METHODS

We retrospectively reviewed the records of patients with Enneking stage 3 GCTB from January 2006-December 2015. Extended curettage was performed in patients in whom there was a moderate expansile lesion, minimal/no articular cartilage damage, and less than 50% of cortical deformation compared to its circumference from a CT scan/MRI. The percentages of cortical deformation were collected. Surgical complications, recurrence, and metastatic rates were analyzed.

RESULTS

There were 28 extended curettage and 41 wide resections. The mean percentages of cortical deformation compared to circumference were 52.6% (range, 23.9-81.9%) and 91.6% (range, 52.1-100%)(P < 0.01) for the curettage and wide resection groups, respectively. There were three recurrences, 2/28 (7.1%) from the curettage group and 1/41 (2.4%) from the resection group (P = 0.56). There were no cases of pulmonary metastasis. There were two complications in the curettage group and five complications in the resection group.

CONCLUSION

Both extended curettage and wide resection are useful methods to treat Enneking stage 3 GCTB. Extended curettage with proper technique is a viable option showing no difference in local recurrence rate and potentially fewer complications. Preference to do extended curettage in patients in whom when the articular cartilage has minimal or no destruction, a moderate expansile lesion and the cortical deformation is less than 50% of the circumference.

Malignant giant cell tumour of bone: a review of clinical, pathological and imaging features

Giant cell tu mour accounts for up to 5% of all bone tumours and malignant giant cell tumour arises in < 10% of cases, representing sarcomatous transformation. Primary malignant giant cell tumour of bone occurs when sarcomatous tissue is observed within conventional giant cell tumour histologically on initial presentation. Secondary malignant giant cell tumour of bone occurs in a region of previously treated giant cell tumour, with most cases arising due to prior radiotherapy. Malignancy in giant cell tumour of bone does not have any unique clinical or imaging features compared to conventional aggressive disease. Historically, malignant giant cell tumour of bone has a poor prognosis which is worse in cases of secondary malignancy. This article aims to present the clinical, pathological and imaging features of MGCTB based on a review of the literature and illustrated by examples from our experience.

Metastatic giant cell tumour of bone: a narrative review of management options and approaches

Giant cell tumour of bone (GCTB) is a locally aggressive bone neoplasm with a rare tendency to metastasise, most commonly to the lungs. The management of metastatic GCTB (metGCTB) is controversial due to its unpredictable behaviour. Asymptomatic patients should be monitored radiologically and undergo treatment only when disease progression occurs. Surgery is recommended for resectable metGCTB. Denosumab, a monoclonal antibody which inhibits receptor activator of nuclear factor‐κB ligand, is recommended for unresectable metGCTB with evidence from phase II trials demonstrating its safety and efficacy. Relapse after denosumab withdrawal may occur and prolonged treatment may be associated with serious adverse events, thus further research is warranted to inform a maintenance regimen with reduced dosing and frequency. Combined denosumab and bisphosphonate therapy has the potential to achieve sustained disease control or remission in unresectable metGCTB without requiring long‐term treatment and should be evaluated in prospective trials. Various novel agents have demonstrated in vitro and anecdotal efficacy and warrant further evaluation.

Benign Bone Tumors: An Overview of What We Know Today

Nonmalignant bone tumors represent a wide variety of different entities but maintain many common features. They usually affect young patients, and most can be diagnosed through imaging exams. Often asymptomatic, they can be discovered incidentally. Due to their similarities, these tumors may be challenging to diagnose and differentiate between each other, thus the need for a complete and clear description of their main characteristics. The aim of this review is to give a picture of the benign bone tumors that clinicians can encounter more frequently in their everyday work.

Current Concepts in the Treatment of Giant Cell Tumors of Bone

Simple Summary

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

Abstract

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

Multiple Pulmonary Metastases of Recurrent Giant Cell Tumor of Bone with Expression of VEGFR-2 Successfully Controlled by Denosumab and Apatinib: A Case Report and Literature Review

Giant cell tumor of bone (GCTB) is a rare, benign, but locally aggressive bone tumor. It has a high tendency for local recurrence, which may increase the incidence of lung metastasis. Currently, an optimal treatment strategy has not been established because of the rarity of pulmonary metastatic GCTB. Denosumab is the preferred regimen for unresectable metastatic lesions; however, there are no alternative treatment options when patients are resistant to denosumab. Apatinib is a small-molecule tyrosine kinase inhibitor that selectively competes for the vascular endothelial growth factor receptor 2 (VEGFR-2) ATP binding site, and several studies have analyzed the effectiveness of apatinib in advanced or metastatic tumors. However, there is no report of apatinib as an anti-angiogenesis therapy for pulmonary metastatic GCTB to date. Here, we present a case of a 26-year-old female who was diagnosed with recurrent and pulmonary metastatic GCTB. Immunohistochemical (IHC) staining indicated that the tumor cells were positive for VEGFR-2. Denosumab was administered to control the metastases; nevertheless, disease progression was confirmed after four months of treatment. Given the IHC results and rapid disease progression, apatinib was added to the treatment strategy. After 42 months of treatment, the patient showed noticeable symptomatic improvement and considerable tumor shrinkage.

Using Machine Learning to Unravel the Value of Radiographic Features for the Classification of Bone Tumors

Objectives

To build and validate random forest (RF) models for the classification of bone tumors based on the conventional radiographic features of the lesion and patients' clinical characteristics, and identify the most essential features for the classification of bone tumors.

Materials and Methods

In this retrospective study, 796 patients (benign bone tumors: 412 cases, malignant bone tumors: 215 cases, intermediate bone tumors: 169 cases) with pathologically confirmed bone tumors from Nanfang Hospital of Southern Medical University, Foshan Hospital of TCM, and University of Hong Kong-Shenzhen Hospital were enrolled. RF models were built to classify tumors as benign, malignant, or intermediate based on conventional radiographic features and potentially relevant clinical characteristics extracted by three musculoskeletal radiologists with ten years of experience. SHapley Additive exPlanations (SHAP) was used to identify the most essential features for the classification of bone tumors. The diagnostic performance of the RF models was quantified using receiver operating characteristic (ROC) curves.

Results

The features extracted by the three radiologists had a satisfactory agreement and the minimum intraclass correlation coefficient (ICC) was 0.761 (CI: 0.686-0.824, P < .001). The binary and tertiary models were built to classify tumors as benign, malignant, or intermediate based on the imaging and clinical features from 627 and 796 patients. The AUC of the binary (19 variables) and tertiary (22 variables) models were 0.97 and 0.94, respectively. The accuracy of binary and tertiary models were 94.71% and 82.77%, respectively. In descending order, the most important features influencing classification in the binary model were margin, cortex involvement, and the pattern of bone destruction, and the most important features in the tertiary model were margin, high-density components, and cortex involvement.

Conclusions

This study developed interpretable models to classify bone tumors with great performance. These should allow radiographers to identify imaging features that are important for the classification of bone tumors in the clinical setting.

Unusual presentation in Haiti of a recurrent giant cell tumor of bone affecting the distal radius: A case report

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En bloc resection with centralization is a viable approach in low-resource areas.

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Multidisciplinary surgical approaches are necessary in low-resource settings.

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Loss of motion can be compensated with proper rehabilitation measures.

Introduction

Giant cell tumor of bone (GCTB) is a benign-aggressive tumor that has a high-rate of recurrence with curettage resection alone. Patients with GCTB in underserved regions of the world can have progression of the tumor with significant disability due to a lack of specialty care. We present a case of an en bloc resection of an aggressive, recurrent GCTB of the radius with excellent function and no evidence of tumor recurrence two years after surgery.

Presentation of case

A 22-year-old right-hand dominant female in Haiti developed an aggressive recurrence of a giant cell tumor of bone (GCTB) of the distal radius. Treatment consisted of en bloc resection of the distal radius with the proximal row of the carpus and centralization of the ulna. At two-year follow-up, the patient maintained good functional capacity with no clinical or radiological evidence of recurrence.

Discussion

GCTB can cause significant destruction of the bone and articular surface if not treated adequately. Treatment options should be considered carefully in underserved regions of the world based on the resources available. This case exemplifies that complex limb-salvage surgery is possible when coordination of care between international and local surgeons is provided with an emphasis on continuity of care post-operatively.

Conclusion

En bloc resection with centralization of the ulna remains a viable technique to address aggressive GCTB of the distal radius and can be appropriate in resource-limited settings.

Pulmonary metastasis of giant cell tumour: a retrospective study of three hundred and ten cases

BACKGROUND

Giant cell tumour (GCT) is an invasive benign bone tumour, and the incidence of pulmonary metastasis is rare. We are aiming to analyze risk factors of pulmonary metastasis and clinical prognosis for giant cell tumour patients with pulmonary metastasis.

METHOD

We performed a retrospective study of 310 patients with GCT between December 2004 and December 2016. Risk factors of pulmonary metastasis were analyzed by univariate and multivariate logistic regression analysis. Then, the influence of risk factors of overall LR (local recurrence), recurrent tumor at presentation, LR after our therapy, and with soft tissue mass on the pulmonary metastasis-free survival rates was analyzed.

RESULTS

The mean follow-up of the present cohort was 45.6 ± 35.3 months (median, 36.6 months; range, 6.1-193.4 months). Eighteen (5.8%) of 310 patients developed pulmonary metastasis. The average interval from surgery of primary tumour to detection of pulmonary metastasis was 15 months. Multivariate logistic regression analysis showed overall local recurrence was the independent risk factor of developing pulmonary metastasis. Among 18 patients with pulmonary metastasis, sixteen cases had history of local recurrence (88.9%, 16/18), including eleven (68.8%, 11/16) with local recurrence at presentation before receiving our therapy and seven (43.8%, 7/16) with local recurrence after receiving treatment in our hospital. Time to local recurrence had obvious difference between patients with and without pulmonary metastasis. Patients with pulmonary metastasis were prone to recur earlier. Furthermore, overall local recurrence, local recurrence after our therapy, recurrent tumor at presentation, and tumour with a soft tissue mass showed statistical differences in the pulmonary metastasis-free survival rates.

CONCLUSIONS

Giant cell tumour patients with soft tissue mass and overall local recurrence are prone to develop pulmonary metastasis. Although giant cell tumour is a benign tumor, more attention should be paid to the problem of pulmonary metastatic lesions, and chest CT scan should be recommended during follow-up.

Bilateral Lung Metastases From a Phalangeal Giant Cell Tumor of Bone

We describe a rare pediatric case of a phalangeal giant cell tumor of bone with extensive bilateral lung metastases following curettage, wide resection, and amputation. Concurrent peripheral blood eosinophilia and pleural effusion with marked eosinophilia (47%) were present. To discover genetic changes driving tumor metastasis, genomic and transcriptome profiling of the metastatic lung mass as well as germline analysis were performed. Whole exome sequencing detected a histone H3F3A p.G35V missense mutation in tumor cells. RNA sequencing revealed overexpression of receptor activator of nuclear factor kappa-B ligand (RANKL). The patient is alive with no residual disease and uncompromised respiratory function 29 months after amputation of primary tumor and 19 months after surgical resection of his metastatic lung disease.

Malignancy in giant cell tumor of bone in the extremities

Background

Malignancy in giant cell tumor of bone (GCTB) is a rare tumor with relevant literature being sparse. In primary malignant GCTB, distinct areas of benign GCTB are juxtaposed with high-grade sarcoma, while in secondary malignant GCTB sarcoma occurs at the site of previously managed GCTB. This study assesses the distinguishing characteristics of patients with this condition, the time interval for development of secondary malignant GCTB, the outcome of treatment, and explores factors associated with oncologic outcomes.

Methods

This is a retrospective case series of patients from a prospectively collected institutional musculoskeletal oncology database. From January 1998 to December 2016, 1365 patients were managed for extremity GCTBs. 32 (2.3%) patients had malignant GCTB, including 12 with primary malignant GCTB and 20 with secondary malignant GCTB. The study population comprised 18 males and 14 females presenting at a mean age of 33.7 years (±13.0) and followed for a mean of 9.5 years (±7.4). Data were collected on patient and treatment-related factors, and the occurrence of local recurrence, metastasis, and death. The time from the diagnosis of GCTB to the secondary malignant GCTB was defined as the latent period.

Results

Malignant GCTB most commonly presents in the distal femur and proximal tibia with pain and swelling. Radiologically, they are aggressive Campanacci Grade III tumors with prominent bony destruction and soft tissue extension. In the 20 patients with secondary malignant GCTB, the tumors were osteosarcoma in 15, undifferentiated pleomorphic sarcoma in 4 patients and fibrosarcoma in one patient. The mean latent period in patients with secondary malignant GCTB was 7.9 year (±7.3). The median recurrence-free survival (RFS) of secondary malignant GCTB (latent period) and benign GCTB were 61.5 and 19 months respectively (p < 0.001), receiver operating curve analysis found 49.5 months to be the critical threshold, with a longer interval to recurrence being seen in malignant recurrence. The 5 and 10-year overall survival rate of malignant GCTB were 45.8% and 36.1% respectively. The 5-year survival rates of primary malignant GCTB and secondary malignant GCTB were 56.2% and 40.0% respectively (p = 0.188). Adequate surgical margins decreased the local recurrence (LR) rate (P = 0.006). Pulmonary metastasis developed in 69% of patients. The median distant metastasis-free survival between malignant GCTB and benign GCTB were 9 and 21 months (p = 0.002). Chemotherapy was associated with a longer pulmonary metastasis free survival (13 months Vs 6 months, P = 0.002), but not with increased overall survival (57.0% Vs 33.3%, P = 0.167).

Conclusions

Malignant GCTB carries a poor prognosis. Accurate diagnosis is critical to avoid inadequate surgical margins when treating primary malignant GCTB. Aggressive tumors and pulmonary metastasis should raise suspicion for malignant GCTB. Secondary malignant transformation should be suspected in patients presenting with recurrence especially after 4 years. Adjuvant chemotherapy use did not benefit survival, but was associated with increased pulmonary progression-free survival.

Comparison of outcomes of 2 surgical treatments for proximal humerus giant cell tumors: a multicenter retrospective study

BACKGROUND

The incidence of giant cell tumors in the proximal humerus is low. We evaluated 2 surgical treatments for giant cell tumors of the proximal humerus and postoperative upper-extremity function.

METHODS

This study retrospectively analyzed the clinical data of 27 cases of giant cell tumors of the proximal humerus at 4 Chinese medical centers specializing in bone oncology collected between January 2002 and June 2015. All patients were followed up for more than 2 years. The surgical procedures performed for treatment included curettage in 14 patients and segmental resection in 13. The Campanacci grade, occurrence of pathologic fracture, surgical method, complications, and Musculoskeletal Tumor Society score were recorded for each cohort.

RESULTS

The recurrence rate was 7.1% in the curettage group and 15.4% in the segmental resection group. Other postoperative complications occurred in 4 patients with segmental resection, including resorption of the osteoarticular allograft in 2, subluxation of the glenohumeral joint in 1, and prosthetic loosening and exposure in 1. A significant difference in postoperative upper-extremity function was noted between the 2 groups (P < .001).

CONCLUSIONS

Postoperative upper-extremity function in the curettage group was significantly better than that in the segmental resection group. Segmental resection and reconstruction with a large segmental osteoarticular allograft were considered unadvisable. We suggest that extensive curettage should be selected to treat proximal humerus giant cell tumors as much as possible.

Increased Risk of Lung Metastases in Patients with Giant Cell Bone Tumors: A Systematic Review

Giant cell tumors of the bone are rare, usually benign, tumors consisting of large, multinucleated bone cells. Remarkably, these tumors are characterized by aggressive growth. They tend to recur frequently and, in rare cases, metastasize to the lungs. Previous studies tried to identify risk factors for lung metastasis by giant cell bone tumors. Those studies reported different results due to a small number of patients. Therefore, a particularly high risk associated with this type of bone tumor prompted this systematic review and meta-analysis to identify risk factors for the development of lung metastases. The risk factors for lung metastasis by giant cell bone tumors searched for in this study were gender, age, lung metastasis and recurrence period, follow-up time, primary or recurrent tumor, Campanacci grading, tumor localization, disease course, treatment of primary and recurrent tumors, and pulmonary metastases treated by surgery, radiation, and chemotherapy. This meta-analysis identified the features outlined above by comparing the groups of patients with giant cell bone tumors and lung metastases with the control group consisting of patients without lung metastases. The search for suitable studies revealed 63 publications with a total of 4,295 patients with giant cell bone tumors. Of these, 247 (5.8%; 95% confidence interval (95%CI) 5.1-6.5%) patients had lung metastases. Further, the risk factors for lung metastases were the following: recurrence (p < 0.0001), lung metastasis time (p < 0.0001), Campanacci grade II (p = 0.028) and grade III (p = 0.006), localization in the lower limbs (p = 0.0007), curettage (p = 0.0005), and local irradiation of the primary tumor (p = 0.008). All studies showed a high-risk bias due to the absence of blinding of the participants, personnel, and outcome assessment. Special attention should be paid to tumor recurrence in the long follow-up time, since more advanced giant cell bone tumors, particularly in lower extremities, tend to reoccur and metastasize to the lung. Surgical treatment and local irradiation should be performed thoughtfully, with extended follow-up periods.

Management of elbow dysfunction associated with giant cell tumor of the distal humerus: achieving oncologic safety and good function by a combined reconstruction

BACKGROUND

The purpose of our study was to evaluate the functional outcomes and oncologic results of elbow salvage surgery using arthrolysis combined with ligament repair and external fixation for reconstruction of the elbow after tumor excision and autografting.

METHODS

We retrospectively reviewed 6 patients with elbow dysfunction associated with giant cell tumor of the distal humerus. All patients were treated with our combined protocol. We assessed the Musculoskeletal Tumor Society system score, range of motion, Mayo Elbow Performance Score, recurrence, and complications for each patient.

RESULTS

The mean follow-up period was 48 months (range, 36-60 months). There were no cases of postoperative fracture, infection, elbow dislocation, elbow stiffness, or local recurrence. The average Musculoskeletal Tumor Society score was 28 of 30 points (93%; range, 87%-100%). The Mayo Elbow Performance Score improved from a mean of 61 points to 93 points, with mean flexion of 135° and mean extension of 3°.

CONCLUSIONS

Local tumor resection, autografting, and elbow reconstruction by arthrolysis combined with ligament repair and external fixation can be performed with oncologic safety and provide satisfactory functional outcomes with low complication rates.

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

Background

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

Methods

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

Results

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

Conclusions

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

Development and validation of a prognostic index to predict pulmonary metastasis of giant cell tumor of bone

Purpose

Giant cell tumor of bone (GCTB) is an intermittent tumor with a low probability of pulmonary metastasis. Our aim was to investigate the risk factors and establish a nomogram predictive model for GCTB pulmonary metastasis.

Methods

We retrospectively evaluated GCTB patients at our center from 1991 to 2014. The cohort was randomized into training and validation sets. Univariate and multivariate analyses were used to evaluate the risk factors of pulmonary metastasis. A nomogram was established. Internal validation was achieved based on ROC curve and C-index values in the validation set. Decision curve analysis was performed to assess the clinical performance of the nomogram.

Results

417 patients were studied, including benign and malignant GCTBs. The average follow up was 79 months. Pulmonary metastases were observed in 27 cases. Four independent risk factors were identified: malignancy, tumor bearing time, times of recurrence and tumor size. A nomogram was developed to predict pulmonary metastasis with C-index values of 0.857 and 0.785 in the training and validation groups. In the decision curve analysis, patients could benefit from the nomogram, which differentiates patients at high risk for pulmonary metastasis and avoids unnecessary examination. According to the nomogram, patients with final risks of more than 0.06 should be scheduled for further chest scans.

Conclusion

Malignancy, tumor bearing time, times of recurrence and tumor size were independent risk factors for pulmonary metastasis in GCTB patients. The nomogram can accurately predict the risk of pulmonary metastasis and help doctors to make clinical decisions for further chest examinations.