Incidence and progression of osteoarthritis following curettage and cementation of giant cell tumor of bone around the knee: long-term follow-up.

BACKGROUND: Giant cell tumor of bone (GCTB) is a benign locally aggressive tumor frequently treated with intralesional curettage and cementation. The aim of this study was to investigate the long-term incidence of arthritic changes following curettage and cementation of GCTB around the knee. MATERIALS AND METHODS: This study was a retrospective review of patients with GCTB around the knee treated with curettage and cementation with a minimum follow-up of 10 years. The functional results were assessed using the Musculoskeletal Tumor Society (MSTS) score. The arthritic changes were classified using the Kellgren-Lawrence (KL) classification system of osteoarthritis. RESULTS: This study included 119 patients, 54 males and 65 females, with a mean age of 29.4 ± 9.2 years. There were 35 (29.4%) patients with pathological fractures. There were 84 (70.6%) patients with de novo lesions and 35 (29.4%) with recurrent lesions. The mean follow-up period was 13.2 ± 3.16 years. The mean MSTS score was 28.5 ± 1.9. Overall, 25 (21%) patients developed variable degrees of arthritis of KL grade 1 (n = 7), KL grade 2 (n = 11), KL grade 3 (n = 4), and KL grade 4 (n = 3). Ten patients showed progression of arthritis during the follow-up period. Age at presentation, gender, presence of pathological fracture, whether the tumor was de novo or recurrent, and tumor location were not associated with arthritis incidence. CONCLUSIONS: Curettage and cementation can be used safely to treat GCTB around the knee. Arthritis of the knee is a possible complication, but mild grades are expected in most cases. There was no association between arthritis incidence and age, gender, pathological fractures, tumor location, or recurrent tumors. LEVEL OF EVIDENCE: Level IV.

Mid-term results of giant cell tumours with pathologic fractures around the knee: a multicentre retrospective study.

OBJECTIVE: The aims of this work are to present a classification of "complex fracture" and "simple fracture", to compare their features, treatments and prognosis in patients with giant cell tumour with pathologic fractures around the knee, and to determine the best surgical method for patients who have giant cell tumour around the knee with different degrees of fracture. METHODS: Data from 130 patients with pathologic fractures from giant cell tumour around the knee who underwent surgical treatment from March 2000 to November 2015 at 6 institutes around China were collected and analysed. A multicentric study design was used to explore the epidemiological features and to compare differences in the surgical procedures and prognosis of the two fracture groups. The mean age at diagnosis was 37.1 years old (range, 13-77 years). The median follow-up was 126.5 months, ranging from 68 to 370 months. RESULTS: The general clinical and imaging features of the groups of patients with simple and complex fractures, namely, sex, age, the lesion site, living or working environment, eccentric growth patterns, Campanacci grading system, and duration of symptoms before treatment, showed varying degrees of differences, but with no statistical significance (p > 0.05). The incidence rate of surrounding soft tissue mass was 35.2% (32/91) in the group with simple fractures, whereas it was 87.2% (34/39) in the group with complex fractures, which showed a significant difference (p < 0.05). Wide resection and reconstruction with joint replacement were performed more often in patients with complex fractures (61.5%, 24/39). Intralesional procedures were performed more often in patients with simple fractures (56.0%, 51/91). The difference showed significant differences (p < 0.05). The local recurrence rate was 17.6% (16/91) in the group with simple fractures, whereas it was 10.3% (4/39) in the complex fracture group, showing a significant difference (p < 0.05). A total of 2.3% of patients (n = 3,3/130) developed a skip lesion. The complication rates were 4.6% (4/87) and 14.7% (5/34), respectively, in the two groups with simple or complex fractures, showing a significant difference (p < 0.05). The mean MSTS and TESS scores with simple fractures were 26.6 (range, 13-30) and 84.1 (range, 29-100), respectively, whereas the mean scores in the group with complex fractures were 25.5 (range, 18-30) and 78.3 (range, 30-100), respectively, also showing a significant difference (p < 0.05). CONCLUSION: Our classification of "simple fracture" and "complex fracture" could guide decisions regarding the best surgical method for lesions in patients who have giant cell tumour around the knee with different degrees of fracture.

Prognostic Factors for Survival in Patients with Malignant Giant Cell Tumor of Bone: A Risk Nomogram Analysis Based on the Population.

BACKGROUND Malignant giant cell tumor of bone (MGCTB) is a rare histological type of malignant tumor that has a high tendency for local relapse and distant metastasis and ultimately leads to a poor prognosis. The purpose of this study was to describe the epidemiological features, identify the prognostic factors, and construct nomograms for patients with MGCTB. MATERIAL AND METHODS Patients with MGCTB that was histologically diagnosed between 1973 and 2014 were selected from the Surveillance, Epidemiology, and End Results (SEER) database as a training set. Survival analysis, Lasso regression, and random forests were used to identify the prognostic variables and establish the nomograms for patients with MGCTB, while an external cohort of 37 patients from our own institution and an external cohort of 163 patients from the SEER database in 2016 were used to validate the generalization performance of the nomograms. RESULTS In total, univariate and multivariable analysis indicated that age, International Classification of Diseases for Oncology, historical stage, primary site, surgery information, radiotherapy, and chemotherapy were independent prognostic variables for overall survival or cause-specific survival. Nomograms based on the multivariable models were built to predict survival, and we achieved a higher C-index in subsequent multidimensional validation. CONCLUSIONS Age, historical stage, and chemotherapy were independent prognostic variables for overall survival and cause-specific survival of MGCTB patients, and radiotherapy and primary site were independent prognostic variables for overall survival. Nomograms based on significant clinicopathological features and clinical experience can be effective in predicting the probability of survival for MGCTB patients.

Primary Bone Tumors in North of Jordan.

OBJECTIVE: Primary tumors of bone are relatively uncommon. Little information is available about the etiology, pathophysiology, risk factors and epidemiologic features of bone tumors. In this article, we present the epidemiological data about the primary (benign and malignant) bone tumors in Jordan. METHODS: Retrospectively, we identified and assessed those patients who were diagnosed with primary bone tumor between January 2004 and December 2018 at King Abdullah University Hospital. The following information was obtained: demographics (age, sex), clinical presentation, and location of the tumor. Also, the histopathological results and finding and recurrence of the tumors were retrieved. The included primary bone tumors were those tumors fulfill the World Health Organization classification of soft tissue and bone tumors. RESULTS: During the study period, four-hundred and thirty-seven cases of the primary bone tumor were diagnosed in our institution. More than half of the cases were males (52.5% males and 47.5% females). In most cases, young adults are affected. The mean age for the diagnosis of giant cell tumor of bone (GCTB) is 34.1 years. The appendicular skeleton was involved in 269 (81.5%) patients while the axial skeleton in 60 patients. The most common encountered pathology is the multiple myeloma with 120 patients. After that, osteochondroma was diagnosed in 110 patients. Females were mostly affected by giant cell tumor while the osteochondroma and chondrosarcoma were seen mostly in males. Multiple myeloma tends to develop in elderly while juvenile ossifying fibroma occurred in young pediatrics and Ewing sarcoma in school-age children and adolescents. Giant cell tumor and osteoid osteoma have the tendency to recur. CONCLUSION: The diagnosis of primary bone tumors is of particular important. The reporting of epidemiological studies is essential in order to expand our knowledge regarding this uncommon type of tumors.

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.

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

OBJECTIVE: Giant cell tumors (GCTs) constitute 5% of all primary bone tumors with spinal GCTs (SGCTs) accounting for 2%-15% of all GCTs. The standard of care for SGCT has been maximal surgical resection. However, many adjuvant therapies have been used owing to the difficulty in achieving gross total resection combined with the high local recurrence rate. The purpose of the present study was to analyze the incidence, management, and outcomes of SGCT. METHODS: Patients with diagnosis codes specific for SGCT were queried from the National Cancer Database from 2004 to 2016. The outcomes were investigated using Cox univariate and multivariate regression analyses, and survival curves were generated for comparative visualization. RESULTS: The search criteria identified 92 patients in the NCDB dataset from 2004 to 2016 with a diagnosis of SGCT. Of the 92 patients, 64.1% had undergone surgical intervention, 24.8% had received radiotherapy, and 15.2% had received immunotherapy. Univariate analysis revealed that age ≥55 years and tumor location in the sacrum/coccyx were associated with worsened overall survival (OS) and that surgical resection was associated with improved OS. On multivariate analysis, age 55-64 years was associated with worsened OS, and radical surgical resection was associated with improved OS. The survival analysis revealed improved OS with surgery but not with radiotherapy, chemotherapy, or immunotherapy. CONCLUSION: SGCT is a rare primary bone tumor of the vertebral column. The standard of care has been surgical resection with the goal of gross total resection; however, adjuvant therapies have often been used. Our study found that surgical resection significantly improved OS and that immunotherapy neared significance in improving OS.

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

BACKGROUND: In 2013, denosumab was introduced as peri-operative adjuvant treatment for giant cell tumor (GCT) of bone as it inhibits osteoclast activity. It is suggested that denosumab relives pain, facilitate curettage in lesions requiring resection initially. However, controversy remains whether denosumab increases the risk of local recurrence after surgery. METHODS: Medline, Embase and the Cochrane Library were comprehensively searched in June 2019 to identify studies investigating the clinical outcome of GCT of bone with and without peri-operative denosumab after surgery. Data were gathered and a meta-analysis was conducted. RESULT: Ten studies with 1082 cases (169 in denosumab group, 913 in control group) were included. Overall, denosumab was associated with significantly higher risk of recurrence(P < 0.02) and inferior 5 year recurrence free survival(P = 0.000). Denosumab and curettage has a relatively higher risk of recurrence comparing to curettage alone(P = 0.07). The risk of recurrence is not significantly increased if denosumab was administered both preoperatively and postoperatively(P = 0.24). CONCLUSION: Administration of denosumab is associated with increased risk of recurrence due to a variety of reasons, though it is proven effective in relieving pain, enabling curettage and improved functional outcome. Post-operative denosumab is recommended as it continuously suppress/eliminate residue tumor cells.

Giant cell tumors combined with secondary aneurysmal bone cysts are more likely to develop postoperative recurrence: A retrospective study of 256 cases.

PURPOSE: The epidemiology and clinicopathology of aneurysmal bone cysts (ABCs) secondary to giant cell tumors of bone (GCTBs) have been well documented in the previous literature. However, reports on whether secondary ABCs could affect the postoperative recurrence of GCTBs are rare. This study analyzed the effects of secondary ABCs and other relevant clinical factors on the postoperative recurrence of GCTBs of the extremities. METHODS: We retrospectively analyzed 256 cases of GCTBs of the extremities that were treated surgically at our institution. Among them, there were 60 patients diagnosed with GCTBs combined with secondary ABCs and 196 patients diagnosed with simple GCTBs. Intralesional curettage and tumor resection were performed in 136 and 120 cases, respectively. Univariate analysis, Kaplan-Meier survival analysis, and multivariate regression analysis were used to assess the factors for postoperative recurrence. The follow-up period was at least 24 months. RESULTS: The total postoperative recurrence rate was 32%. The recurrence rate in the secondary ABCs group was significantly higher than that in the simple GCTBs group (53.3% vs 25.5%, P < 0.05). Curettage was associated with a higher recurrence rate than tumor resection (42.5% vs 20%, P < 0.05). Kaplan-Meier survival analysis showed that patients with GCTBs combined with secondary ABCs and who were treated by intralesional curettage had a decreased disease-free survival rate. The hazard ratio was 2.18 (95% confidence interval [CI], 1.15-4.13) for the group of GCTB combined with ABCs ( P = 0.01) and 1.97 (95% CI, 1.22-7.50) for the curettage group ( P = 0.01), respectively. Multivariate regression analysis revealed that the presence of secondary ABCs and curettage were independent factors for recurrence of GCTBs. CONCLUSION: According to the results of this study, the presence of secondary ABCs is a potential risk factor for postoperative relapse of GCTBs.

Malignancy in Giant Cell Tumor of Bone: A Review of the Literature.

BACKGROUND: Primary and recurrent giant cell tumor of bone is typically benign; however, rarely giant cell tumor of bone can undergo malignant transformation. Malignancy in giant cell tumor of bone may be primary (adjacent to benign giant cell tumor of bone at first diagnosis) or secondary (at the site of previously treated giant cell tumor of bone). Malignant giant cell tumor of bone has a poor prognosis; it is important to distinguish malignant from benign lesions to facilitate appropriate management. The true incidence of malignant giant cell tumor of bone is not known, probably owing to inaccurate diagnosis and inconsistent nomenclature. We have analyzed current data to provide a robust estimate of the incidence of malignancy in giant cell tumor of bone. METHODS: A literature search was performed to source published reports of primary and secondary cases of malignant giant cell tumor of bone. Studies that reported a denominator were used to estimate the incidence of malignancy. RESULTS: We identified 4 large series of patients with malignant giant cell tumor of bone that provided data on 2315 patients with giant cell tumor of bone. Across these studies, the cumulative incidence of malignancy was 4.0%; the cumulative incidence of primary malignancy was 1.6% compared with 2.4% for secondary malignancy. Our analyses confirmed that most malignant giant cell tumor of bone is secondary and occurs following radiation. In addition, data from 8 small series showed that 4.8% of patients with giant cell tumor of bone who received radiation therapy developed secondary malignancy. CONCLUSIONS: Malignant giant cell tumor of bone is rare, and its identification is hindered by a lack of clear diagnostic criteria. For optimal care of patients with giant cell tumor of bone, we recommend: comprehensive histologic sampling to ensure accurate diagnoses; watchful follow-up, particularly for patients treated with radiation; and timely treatment of local recurrence.

Prognostic factors for local recurrence in extremity-located giant cell tumours of bone with pathological fracture.

AIMS: The aim of this paper was to investigate the prognostic factors for local recurrence in patients with pathological fracture through giant cell tumours of bone (GCTB). PATIENTS AND METHODS: A total of 107 patients presenting with fractures through GCTB treated at our institution (Royal Orthopaedic Hospital, Birmingham, United Kingdom) between 1995 and 2016 were retrospectively studied. Of these patients, 57 were female (53%) and 50 were male (47%).The mean age at diagnosis was 33 years (14 to 86). A univariate analysis was performed, followed by multivariate analysis to identify risk factors based on the treatment and clinical characteristics. RESULTS: The initial surgical treatment was curettage with or without adjuvants in 55 patients (51%), en bloc resection with or without reconstruction in 45 patients (42%), and neoadjuvant denosumab, followed by resection (n = 3, 3%) or curettage (n = 4, 4%). The choice of treatment depended on tumour location, Campanacci tumour staging, intra-articular involvement, and fracture displacement. Neoadjuvant denosumab was used only in fractures through Campanacci stage 3 tumours. Local recurrence occurred in 28 patients (25%). Surgery more than six weeks after the fracture did not affect the risk of recurrence in any of the groups. In Campanacci stage 3 tumours not treated with denosumab, en bloc resection had lower local recurrences (13%), compared with curettage (39%). In tumours classified as Campanacci 2, intralesional curettage and en bloc resections had similar recurrence rates (21% and 24%, respectively). After univariate analysis, the type of surgical intervention, location, and the use of denosumab were independent factors predicting local recurrence. Further surgery was required 33% more often after intralesional curettage in comparison with resections (mean 1.59, 0 to 5 vs 1.06, 0 to 3 operations). All patients treated with denosumab followed by intralesional curettage developed local recurrence. CONCLUSION: In patients with pathological fractures through GCTB not treated with denosumab, en bloc resection offers lower risks of local recurrence in tumours classified as Campanacci stage 3. Curettage or resections are both similar options in terms of the risk of local recurrence for tumours classified as Campanacci stage 2. The benefits of denosumab followed by intralesional curettage in these patients still remains unclear.

Incidence and demographics of giant cell tumor of bone in The Netherlands: First nationwide Pathology Registry Study.

Background and purpose - Giant cell tumors of bone (GCT-B) are rare, locally aggressive tumors characterized by an abundance of giant cells. Incidence studies for GCT-B are rare. This is the first study using a fully automated 100% covering pathology database, the nationwide Dutch Pathology Registry (17 million inhabitants), PALGA, to calculate incidence rates for GCT-B. Patients and methods - From PALGA, all pathology excerpts were retrieved for patients diagnosed with GCT-B, giant cell tumors of tenosynovium, and giant cell tumors of soft tissue between January 1, 2009 and December 31, 2013. The incidence of GCT-B was calculated. Results - In total, 8,156 excerpts of 5,922 patients were retrieved; these included 138 first GCT-B diagnosis. For GCT-B the incidence was 1.7 per million inhabitants per year with a male to female ratio of 1:1.38 and a median age of 35 years (9-77). Most common localization was the femur (35%), followed by the tibia (18%). No differences in localization according to age and sex were found. The incidence rate of local recurrence was 0.40 per million inhabitants per year. Interpretation - This is the first nationwide study reporting the incidence of GCT-B, based on a nationwide pathology database with 100% coverage of pathology departments. Current incidence calculations are based only on doctor-driven registries. We confirmed that GCT-B is a rare disease with an incidence that is slightly higher than previously published. The relatively young median age of patients and the high incidence of recurrence stresses the importance of developing more effective treatments for this disease.

An acetabular-preserving procedure for pelvic giant cell tumor involving partial acetabulum.

BACKGROUND: The management of pelvic giant cell tumors (GCTs) involving the acetabulum remains a challenge for surgeons on how to balance the relative benefits of minimizing recurrence and maintaining postoperative hip function. The present study was to present and evaluate the clinical indications, operative technique, and outcomes of pelvic GCTs involving partial acetabulum treated with multiplanar osteotomy and reconstruction of autogenous femoral head bone grafts combined with cementless total hip arthroplasty (THA). METHODS: We retrospectively reviewed seven patients with pelvic GCTs involving partial acetabulum who underwent multiplanar osteotomy and reconstruction of autogenous femoral head bone grafts combined with cementless THA from January 2010 to October 2014. We assess the outcome including the bone graft healing, nonunion, hardware failure, infection, tumor recurrence, and metastasis. And the functional outcome was evaluated by the Musculoskeletal Tumor Society (MSTS)93 score. RESULTS: All patients were followed up for a mean of 38.1 months (range 26-61 months). All bone grafts are union. No failure of acetabular components, wound healing problem, or deep infection was suspected. No patient experienced metastasis. Recurrence was observed in one out of seven patients, treated by extended resection and implanting iodine ions in the surgical area. The mean MSTS93 score was 29.4 (range 28-30). All patients were disease-free and resumed activities of daily living at the most recent follow-up. CONCLUSIONS: As long as one of the two columns is retained and the resulting defect does not exceed the supra-acetabular line, multiplanar osteotomy and reconstruction of autogenous femoral head bone grafts combined with cementless THA is a viable strategy for the treatment of pelvic GCTs involving partial acetabulum. However, a large-scale prospective clinical study is still needed to verify these procedures.

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

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

Surveillance for lung metastasis from giant cell tumor of bone.

BACKGROUND AND OBJECTIVES: Literature on surveillance for lung metastasis from giant cell tumor of bone (GCTB) is scarce. We aimed to develop one by determining: (1) the optimal surveillance schedule by analyzing time-to-event data, taking into account the predictive factors, and (2) the effective diagnostic modality. METHODS: A total of 333 patients who underwent surgery for GCTB were followed for at least 2 years. All had chest radiography, and 169 had additional CT for surveillance. Time to lung metastasis and cumulative incidence were calculated, and diagnostic performance between chest radiography and CT was compared. RESULTS: Twenty-five (7.5%) of 333 patients developed lung metastasis, and local recurrence (LR) was the only predictive factor (RR = 6.54). Median interval from LR to metastasis was 15 months, and 17 (85%) of the 20 metastases with LR occurred within 3 years of LR. Cumulative post-LR incidences at 1, 3, and 5 years were 15.4%, 21.5%, and 21.5%, respectively. CT was more sensitive (100% vs 32%), and had higher positive predictive value (81% vs 57%) and accuracy (96% vs 93%). CONCLUSIONS: Intensified lung surveillance is warranted for GCTB patients with LR, especially for 3 years from diagnosis of LR. CT is effective for detecting lung metastasis from GCTB.

Denosumab in patients with giant-cell tumor of bone in Norway: results from a nationwide cohort.

BACKGROUND: Denosumab is a relatively new treatment option for patients with giant-cell tumor of bone (GCTB). The purpose of this study was to report the results for patients treated in Norway. MATERIALS AND METHODS: Patients treated with denosumab for GCTB were identified from the clinical databases at the Norwegian sarcoma reference centers. Data were retrieved from the clinical databases and supplemented by retrospective review of patient records. Denosumab was given as a subcutaneous injection every 4 weeks with loading doses on day 8 and 15 in cycle 1. RESULTS: Eighteen patients treated with denosumab for GCTB were identified. Denosumab was given for recurrent disease in seven cases and as first-line treatment in 11 patients, of which 6 received therapy as part of a neoadjuvant/adjuvant strategy and 5 for surgically unsalvageable primary tumor. Ten of 12 patients with unresectable disease are still on denosumab without progression with median treatment duration of 41 months (range 18-60). Two patients discontinued treatment due to osteonecrosis of the jaw and reduced compliance, respectively. In the adjuvant group, four patients experienced disease recurrence after stopping denosumab. In three of six patients, the extent of surgery was reduced due to neoadjuvant therapy. Seventeen of 18 patients underwent response evaluation with 18F-FDG PET/CT at median 4.7 weeks from starting denosumab. Median baseline SUVmax was 11.0 and median SUVmax at evaluation was 4.9 (p < 0.001). CONCLUSIONS: In a nationwide GCTB patient cohort, denosumab was an effective agent and durable responses were observed. Our results do not support the use of adjuvant therapy in routine clinical practice. 18F-FDG PET/CT could be a valuable tool for early response evaluation.

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

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

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

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

Population-based study of giant cell tumor of bone in Sweden (1983-2011).

INTRODUCTION: Giant-cell tumor of bone (GCTB) is a locally aggressive histologically benign neoplasm with a less common malignant counterpart. Longitudinal data sources on GCTB are sparse, limited to single institution case series or surgical outcomes studies. The Swedish Cancer Registry is one of the few national population-based databases recording GCTB, representing a unique source to study GCTB epidemiology. We estimated incidence rate (IR) and overall mortality rates based on registry data. MATERIALS AND METHODS: We identified patients with a GCTB diagnosis in the Swedish Cancer Registry from 1983 to 2011: benign (ICD-7 196.0-196.9; PAD 741) and malignant (PAD 746). Results were stratified by age at diagnosis, gender, and anatomical lesion location. RESULTS: The cohort included 337 GCTB cases (IR of 1.3 per million persons per year). The majority (n=310) had primary benign GCTB (IR of 1.2 per million per year). Median age at diagnosis was 34 years (range 10-88) with 54% (n=183) females. Malignant to benign ratio for women was 0.095 (16/167) and for men 0.077 (11/143). Incidence was highest in the 20-39 years age group (IR of 2.1 per million per year). The most common lesion sites were distal femur and proximal tibia. Mortality at 20 years from diagnosis was 14% (n=48) and was slightly higher for axial (17%; n=6) and pelvic (17%; n=4) lesions. Recurrence occurred in 39% of primary benign cases and 75% of primary malignant cases. CONCLUSIONS: In our modern population-based series primary malignant cases were uncommon (8%), peak incidence 20-39 years with slight predominance in women. Recurrence rates remain significant with overall 39% occurring in benign GCTB, and 75% in malignant form. The linkage between databases allowed the first population based estimates of the proportion of patients who received surgery at initial GCTB diagnosis, and those who also received subsequent surgeries.

Incidence Trends in the Diagnosis of Giant Cell Tumor of Bone in Sweden Since 1958.

BACKGROUND: The Swedish Cancer Registry (founded in 1958) constitutes a unique resource for epidemiological studies of giant cell tumor of bone with potential for use for population-based studies of incidence over time. The aim of this study was to provide what we believe is the first modern population-based assessment of the incidence trends of giant cell tumor, a unique osteoclastogenic lytic stromal tumor with both benign and malignant histological forms, and to compare the findings with data from the same registry on osteosarcoma, a tumor that may display similar histological characteristics. METHODS: Cases were identified with use of codes for pathological bone tumor (International Classification of Diseases [ICD]-7 196). Specific morphological coding distinguishes benign (PAD 741) from malignant giant cell tumor (PAD 746) and osteosarcoma (PAD 766). RESULTS: During the period of 1958 to 2011, 4625 bone tumors were reported, including 505 giant cell tumors (383 benign and 122 malignant) and 1152 osteosarcomas. From 1958 to 1982 the ratio of malignant to benign giant cell tumors was 1.3, whereas from 1983 to 2011 the ratio inverted to 0.09, suggesting a change in the reporting or diagnosis of malignant or benign cases. Cases of giant cell tumor diagnosed from 1983 to 2011 displayed an age and sex distribution (median age at diagnosis, 34.0 years; 54% female) that were consistent with those in large published case series but differed from those in 1958 to 1982 (median age at diagnosis, 31.5 years; 48% female). The most current data (1983 to 2011) showed the giant cell tumor incidence in Sweden to be 1.3 per million per year, while the osteosarcoma incidence was 2.3 per million per year. CONCLUSIONS: Early Swedish Cancer Registry data (1958 to 1982) revealed a higher proportion of malignant giant cell tumors than seen in large sequential case series and a distinct age and sex profile compared with more recent data (1983 to 2011). This likely represents changes in the diagnostic workup and introduction of multidisciplinary review of giant-cell-containing tumors around 1982. Recent data may reflect the impact of expert centralized biopsy and multidisciplinary case review and more comprehensive reporting of benign giant cell tumors.