Prognostic factors of chondroblastic osteosarcoma and nomogram development for prediction: A population-based, STROBE-compliant study.

ABSTRACT: The present study aimed to develop nomograms to predict survival in patients with chondroblastic osteosarcoma (COS).An analysis was conducted of 320 cases of COS collected from the surveillance, epidemiology, and end results (SEER) database between 2004 and 2015. Independent prognostic factors were screened using univariate and multivariate Cox analyses. Subsequently, nomograms were established to predict the patients' cancer-specific survival (CSS) and overall survival (OS) rates. The prediction accuracy and discriminative ability of the nomograms were examined using calibration curves and the concordance index (C-index).As revealed in the univariate and multivariate Cox regression analysis, age, tumor size, the primary site, the presence of metastasis, a history of having undergone surgery, and a history of having received radiotherapy were found to be independent prognostic factors associated with survival in patients with COS (all P < .05). Furthermore, age >39 years, the presence of distant metastasis, no history of having undergone any surgery, and tumor size >103 mm were found to be associated with poor prognosis in patients, while the primary site of the mandible and no history of having undergone radiotherapy showed associations with a more favorable prognosis in patients. Next, nomograms were constructed to predict the OS and CSS in patients with COS.We constructed nomograms that can provide accurate survival predictions in patients with chondroblastic osteosarcoma. These nomograms can help surgeons customize the treatment strategies for patients with chondroblastic osteosarcoma.

Nomograms for predicting overall survival and cancer-specific survival of chondroblastic osteosarcoma patients.

BACKGROUND: The establishment of precise and personalized prediction systems for chondroblastic osteosarcoma patients is important for guiding the treatment. METHODS: The univariate logrank test and multivariate Cox regression analysis were performed to identify independent prognostic factors for overall survival (OS) and cancer-specific survival (CSS). Nomograms were constructed to estimate the OS and CSS based on these factors. Internal and external validation was performed. The predictive power of the nomograms was determined by C-index and calibration plots. RESULTS: A total of 401 chondroblastic osteosarcoma cases were identified. Univariate and multivariate analysis revealed that age at diagnosis, histological grade, tumor size, Surveillance, Epidemiology, and End Results stage, and surgical resection were independent prognostic factors for OS and CSS. The five factors were incorporated to construct the nomograms for estimating the 3- and 5-year OS and CSS. The C-index values for the internal validation of the OS and CSS nomogram were 0.732 and 0.746, respectively, and for the external validation were 0.780 and 0.808, respectively. The calibration curves revealed that the predicted OS and CSS could well match the actual survival rate. CONCLUSIONS: The nomograms for predicting 3- and 5-year OS and CSS were constructed and were proved to be accurate and reliable by the internal and external validation.

Management of cranial chondroblastoma in adults; a pooled analysis.

OBJECTIVES: Chondroblastoma is a rare bone tumour that often affects children more than adults. The adult cranial affection is a unique presentation of the disease (less than 2%) that mandates specific management. Through this pooled-analysis, we aimed to examine this disease group and obtain reliable scientific conclusions. METHODS: The literature was searched for case-reports of cranial chondroblastoma. Afterwards, a pooled analysis was done for the selected articles. The data in question were the patient's age, gender, disease site, modalities of treatment, disease control, salvage treatment, and disease-specific survival. RESULTS: 122 case reports were retrieved from the literature. The median age at diagnosis was 38.5 years. Up to the moment, the standard of care remains complete resection. The relapse-free survival was 29.5 months, with a three-year relapse rate of 9% and disease-specific mortality of 0%. Most of the relapses were salvaged excellently with excision. The strongest predictor for relapse was the post-resection residual disease, with three-years relapse rates of 23.8% and 2.4% for positive and negative residuals, respectively. Adjuvant Radiotherapy failed to improve the relapse rates. CONCLUSION: Complete surgical excision is the standard of care. Post-surgical residual is the only adverse prognostic factor that predicts poor disease control.

Prognostic factors to survival of patients with chondroblastic osteosarcoma.

This study was aimed to reveal the changes in survival rates and prognostic factors to survival of chondroblastic osteosarcoma (COS).Patients from the Surveillance, Epidemiology, and End Results (SEER) database were retrieved. Kaplan-Meier survival analysis and Cox proportional hazard model were used during analysis.There were significant differences on overall survival between subtypes of osteosarcoma (P < .001*). Overall survival of COS did not change significantly during last forty years (P = .610), and cancer-specific survival increased to a plateau in 1980s and then remained stable (P = .058). Younger onset age, patients of white race, well and moderately differentiated tumors, and surgery independently predicted better overall (Hazard ratio [HR]: 1.034, P < .001*; HR: 0.538, P = .004*; HR: 0.240, P = .020* and HR: 0.350, P < .001*, respectively) and cancer-specific (HR: 1.031, P = .002*; HR: 0.592, P = .036*; HR: 0.098, P = .027* and HR: 0.253, P < .001*, respectively) survival. Metastasis at diagnosis independently predicted worse overall (HR: 3.108, P < .001*) and cancer-specific (HR: 4.26, P < .001*) survival compared to no metastasis.Younger onset age, white race, well and moderately differentiated tumors, no metastasis at diagnosis and surgical resection can independently predict better overall and cancer-specific survival of COS.

Diagnostic value of histone 3 mutations in osteoclast-rich bone tumors.

Differentiating osteoclast-rich lesions of bone (giant cell tumor of bone [GCTB], chondroblastoma [CBA], and aneurysmal bone cyst [ABC]) can be challenging, especially in small biopsies or fine-needle aspirations. Mutations affecting codons 34 and 36 of either H3 Histone Family Member 3A (H3F3A) and/or 3B (H3F3B) are characteristically seen in GCTB and CBAs. We devised a simple assay to identify these mutations and evaluated its applicability for routine clinical diagnosis. One hundred twenty-four tissue specimens from 108 patients (43 GCTBs, 38 CBAs and 27 ABCs) were collected from the archives of the Calgary Laboratory Services/University of Calgary and Vanderbilt University Medical Center. Histology was reviewed by an expert orthopedic pathologist. A single base extension assay (SNaPshot) is used to interrogate each nucleotide in codons 34 and 36 of H3F3A and codon 36 of H3F3B. Final diagnoses were generated after re-reviewing cases and incorporating molecular findings. Of 43 GCTBs, 38 (88%) had an H3F3A G34W mutation; 35 of 38 CBAs (92%) had a K36M mutation in either H3F3B (N = 31; 82%) or H3F3A (N = 4; 11%); none of 27 ABCs had a tested mutation. Molecular findings changed the histomorphologic diagnosis in 5 cases (3 GCTB changed to ABC, and 2 ABC changed to GCTB). These findings support the diagnostic utility of mutational analysis for this differential diagnosis in certain challenging cases when clinicoradiologic and histomorphologic features are not definitive, particularly for distinguishing cellular ABC versus GCTB with secondary ABC.

Chondroblastoma of the lumbar spine with cauda equina syndrome.

STUDY DESIGN: Case report. OBJECTIVE: To describe the clinical presentations, radiological features and clinical progress of a rare case of chondroblastoma of the lumbar spine. SETTING: Regional Hospital, Hong Kong, China. METHOD: A 54-year-old male patient presented with low back pain and left sciatica. X-ray and MRI revealed tumour infiltration of the fifth lumbar vertebrae and left paraspinal muscles, which was found to be a chondroblastoma by repeated open biopsies. The tumour was removed surgically by combined anterior and posterior approaches, followed by spinal fusion and instrumentation. RESULTS: The anterior tricortical bone graft was complicated with fracture and nonunion. Surgical re-exploration confirmed local recurrence of tumour macroscopically and histologically. The patient developed symptoms and signs of cauda equina syndrome gradually despite repeated surgery and irradiation. The patient eventually died of complications of local recurrence and neurological deficit at 3 years and 8 months after the first operation. CONCLUSION: This is the first case report of chondroblastoma of the lumbar spine. The clinical profile of this patient and the evidence from the literature review suggests that spinal chondroblastoma has a very aggressive behaviour with high recurrence and mortality rate.

Extendible replacements of the proximal tibia for bone tumours.

Limb salvage is now customary in the treatment of primary bone tumours. The proximal tibia is a frequent site for these neoplasms but reconstruction, especially in children, is a formidable challenge. We reviewed 20 children with extendible replacements of the proximal tibia, all with a minimum follow-up of five years. Five died from their disease and, of the remaining 15, four had above-knee amputations for complications. Infection occurred in seven patients; in five it was related to the lengthening procedure. Aseptic loosening is inevitable in the younger children and only two have avoided a revision, amputation or other major complication; both were aged 12 years at the time of the initial surgery. Despite this, 11 children are alive with a functioning leg and a mean Musculoskeletal Tumour Society functional score of 83%. The lengthening mechanisms used in our series required extensive open operations. We are now using a simpler, minimally invasive, technique which we hope will decrease the incidence of complications. At present, the use of extendible prostheses of the proximal tibia remains an experimental procedure.