Primary malignant bone tumors--recent developments

Health-related quality of life in patients with extremity bone sarcoma after surgical treatment: a systematic review

PURPOSE

We conducted a systematic review of studies reporting on measurement of health-related quality of life (HRQoL), with a special focus on the use of the preference-weighted instruments, in patients with extremity bone sarcoma treated with limb-salvage surgery or amputation.

METHODS

We searched MedLine, Embase, Cochrane Library and Web of Science for English-language studies reporting on HRQoL of patients with bone sarcoma from inception to 28 August 2023. All records found were independently reviewed by two reviewers. We used the Newcastle-Ottawa Scale (NOS) and the CONSORT 2010 checklist to assess the quality of the cohort and randomised studies, respectively.

RESULTS

The search identified 1225 records, of which 16 studies were included for data extraction. Only one study used a preference-weighted instrument for measuring HRQoL in a small sample of patients (n = 28). Ten studies used the generic SF-36 questionnaire, but no preference-weighted HRQoL based on SF-6D was derived from the SF-36 scores. Most studies comparing HRQoL between amputation and limb-salvage surgery reported no significant differences. Twelve cohort studies scored six or more out of nine points based on the NOS. The only randomised study scored 54% on the CONSORT 2010 checklist.

CONCLUSIONS

The approaches used to measure HRQoL were inconsistent and outcome scores varied substantially. Only one study used preference-weighted instruments for HRQoL measurement. Future research into the surgical treatment of extremity bone sarcoma should consider the use of preference-weighted instruments to measure HRQoL, which will therefore enable economic evaluation for the growing orthopaedic armamentarium of novel surgical interventions.

REGISTRATION

This systematic review was registered with the PROSPERO International prospective register of systematic reviews (CRD42021282380).

Biomechanical Aspects in Bone Tumor Engineering

In the past decades, anticancer drug development brought the field of tumor engineering to a new level by the need of robust test systems. Simulating tumor microenvironment in vitro remains a challenge, and osteosarcoma-the most common primary bone cancer-is no exception. The growing evidence points to the inevitable connection between biomechanical stimuli and tumor chemosensitivity and aggressiveness, thus making this component of the microenvironment a mandatory requirement to the developed models. In this review, we addressed the question: is the "in vivo - in vitro" gap in osteosarcoma engineering bridged from the perspective of biomechanical stimuli? The most notable biomechanical cues in the tumor cell microenvironment are observed and compared in the contexts of in vivo conditions and engineered three-dimensional in vitro models. Impact statement The importance of biomechanical stimuli in three-dimensional in vitro models for drug testing is becoming more pronounced nowadays. This review might assist in understanding the key players of the biophysical environment of primary bone cancer and the current state of bone tumor engineering from this perspective.

Brain metastasis of chondrosarcoma: A case report and literature review

Brain metastases of a chondrosarcoma are extremely rare, and treatment remains controversial. A 54-year-old woman had undergone surgical treatment for a femoral chondrosarcoma and its lung metastases. She presented with visual disturbance and dizziness 22 months after the initial surgery; imaging studies of the brain revealed a metastatic tumor in the left parieto-occipital lobe. Surgical tumor resection was performed; however, only 2 months after gross total resection of the tumor, rapid tumor recurrence was observed. Surgical resection was performed again, followed by intensity-modulated radiation therapy. Three months later, another small brain lesion was detected in the right parietal lobe and was treated with gamma knife stereotactic radiosurgery. No recurrence has been reported 20 months after this radiosurgery for brain metastasis. Thus, surgical treatment combined with several adequate radiation therapy sessions may be a viable treatment strategy for brain metastases of chondrosarcomas.

Advances in The Application and Research of Magnetic Resonance Diffusion Kurtosis Imaging in The Musculoskeletal System

Magnetic resonance diffusion kurtosis imaging (DKI) is an emerging magnetic resonance imaging (MRI) technique that can reflect microstructural changes in tissue through non-Gaussian diffusion of water molecules. Compared to traditional diffusion weighted imaging (DWI), the DKI model has shown greater sensitivity for diagnosis of musculoskeletal diseases and can help formulate more reasonable treatment plans. Moreover, DKI is an important auxiliary examination for evaluation of the motor function of the musculoskeletal system. This article briefly introduces the basic principles of DKI and reviews the application and research of DKI in the evaluation of disorders of the musculoskeletal system (including bone tumors, soft tissue tumors, spinal lesions, chronic musculoskeletal diseases, musculoskeletal trauma, and developmental disorders) as well as the normal musculoskeletal tissues. EVIDENCE LEVEL: 5 TECHNICAL EFFICACY: 1.

Construction of a Diagnostic Model for Distinguishing Benign or Malignant Bone Cancer by Mining miRNA Expression Data

Bone tumor is a kind of rare cancer, the location of which is mainly in bone tissue as well as cartilage tissue. Bone tumor is mainly classified into benign and malignant types. The survival rate of patients with bone tumors can be considerably improved by early detection, and the danger of amputation caused by bone tumors can be greatly reduced. In this study, we first screened the top 25% serum miRNAs with the greatest variance in patients with malignant and benign bone tumor and healthy individuals. The expression of serum miRNAs in patients with bone tumor was then examined using unsupervised clustering and PCA, and the results revealed that the overall expression of serum miRNAs was ineffective in distinguishing patients with benign/malignant bone tumors. Subsequently, we screened 19 miRNA biomarkers that could be used to determine the benign/malignant bone tumor of patients by LASSO logistic regression. These genes were validated using ROC curves. Results showed that there were 11 miRNAs that could accurately distinguish benign/malignant bone tumor alone. These 11 miRNAs were, namely, hsa-miR-192-5p, hsa-miR-137, hsa-miR-142-3p, hsa-miR-155-3p, hsa-miR-1205, hsa-miR-1273a, hsa-miR-3187-3p, hsa-miR-1255b-2-3p, hsa-miR-1288-5p, hsa-miR-6836-5p, and hsa-miR-6862-5p. Next, we established a diagnostic model using logistic regression and validated the diagnostic model using ROC curves; the result of which showed that the model had good diagnostic efficacy. Then, we also verified that the diagnostic model established by these 11 miRNAs could distinguish patients with benign/malignant bone tumor using unsupervised clustering as well as PCA. Finally, by using qPCR, we validated the expression of 11 miRNAs in the serum of patients with malignant and benign bone tumors, as well as healthy volunteers. The results were consistent with the trend of miRNAs expression in public databases. In summary, we examined the differential expression of serum miRNAs in individuals with benign and malignant bone tumors and discovered 11 miRNA biomarkers that could be utilized to discriminate between the two.

Molecular and Translational Research on Bone Tumors

Primary bone tumors (PBTs) represent a huge variety of rare malignancies that originate in the skeletal system [...].

Identification and validation of an anoikis-related lncRNA signature to predict prognosis and immune landscape in osteosarcoma

Background

Anoikis is a specialized form of programmed apoptosis that occurs in two model epithelial cell lines and plays an important role in tumors. However, the prognostic value of anoikis-related lncRNA (ARLncs) in osteosarcoma (OS) has not been reported.

Methods

Based on GTEx and TARGET RNA sequencing data, we carried out a thorough bioinformatics analysis. The 27 anoikis-related genes were obtained from the Gene Set Enrichment Analysis (GSEA). Univariate Cox regression and least absolute shrinkage and selection operator (LASSO) analysis were successively used to screen for prognostic-related ARLncs. To create the prognostic signature of ARLncs, we performed multivariate Cox regression analysis. We calculated the risk score based on the risk coefficient, dividing OS patients into high- and low-risk subgroups. Additionally, the relationship between the OS immune microenvironment and risk prognostic models was investigated using function enrichment, including Gene ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), single-sample gene set enrichment analysis (ssGSEA), and GSEA analysis. Finally, the potential effective drugs in OS were found by immune checkpoint and drug sensitivity screening.

Results

A prognostic signature consisting of four ARLncs (AC079612.1, MEF2C-AS1, SNHG6, and TBX2-AS1) was constructed. To assess the regulation patterns of anoikis-related lncRNA genes, we created a risk score model. According to a survival analysis, high-risk patients have a poor prognosis as they progress. By using immune functional analysis, the lower-risk group demonstrated the opposite effects compared with the higher-risk group. GO and KEGG analysis showed that the ARLncs pathways and immune-related pathways were enriched. Immune checkpoints and drug sensitivity analysis might be used to determine the better effects of the higher group.

Conclusion

We identified a novel prognostic model based on a four-ARLncs signature that might serve as potential prognostic indicators that can be used to predict the prognosis of OS patients, and immunotherapy and drugs that may contribute to improving the overall survival of OS patients and advance our understanding of OS.

A novel necroptosis-related lncRNAs signature effectively predicts the prognosis for osteosarcoma and is associated with immunity

Background: Necroptosis is closely related to tumorigenesis and development. Accumulating evidence has revealed that long non-coding RNAs (lncRNAs) are also central players in osteosarcoma (OS). However, the role of necroptosis-related lncRNAs in OS remains unclear. In the present study, we aim to craft a prognostic signature based on necroptosis-related lncRNAs to improve the OS prognosis prediction.

Methods: The signature based on necroptosis-related lncRNAs was discovered using univariate Cox, least absolute shrinkage and selection operator (LASSO), and multivariate Cox regression analysis. The prognosis efficiency of the signature was then estimated by employing various bioinformatics methods. Subsequently, immunological analysis and Gene Set Enrichment Analysis (GSEA) were used to explore the association between necroptosis-related lncRNAs with clinical outcomes and immune status. More importantly, several necroptosis-related lncRNAs were validated with RT-qPCR.

Results: Consequently, a novel prognosis signature was successfully constructed based on eight necroptosis-related lncRNAs. Meanwhile, the novel necroptosis-related lncRNAs model could distribute OS patients into two risk groups with a stable and accurate predictive ability. Additionally, the GSEA and immune analysis revealed that the necroptosis-related lncRNAs signature affects the development and prognosis of OS by regulating the immune status. The necroptosis-related lncRNA signature was closely correlated with multiple anticancer agent susceptibility. Moreover, the RT-qPCR results indicated several necroptosis-related lncRNAs were significantly differently expressed in osteosarcoma and osteoblast cell lines.

Conclusion: In this summary, a novel prognostic signature integrating necroptosis-related lncRNAs was firstly constructed and could accurately predict the prognosis of OS. This study may increase the predicted value and guide the personalized chemotherapy treatment for OS.

Impact of racial disparities and insurance status in patients with bone sarcomas in the USA : a population-based cohort study

Aims

Socioeconomic and racial disparities have been recognized as impacting the care of patients with cancer, however there are a lack of data examining the impact of these disparities on patients with bone sarcoma. The purpose of this study was to examine socioeconomic and racial disparities that impact the oncological outcomes of patients with bone sarcoma.

Methods

We reviewed 4,739 patients diagnosed with primary bone sarcomas from the Surveillance, Epidemiology and End Results (SEER) registry between 2007 and 2015. We examined the impact of race and insurance status associated with the presence of metastatic disease at diagnosis, treatment outcome, and overall survival (OS).

Results

Patients with Medicaid (odds ratio (OR) 1.41; 95% confidence interval (CI) 1.15 to 1.72) and uninsured patients (OR 1.90; 95% CI 1.26 to 2.86) had higher risks of metastatic disease at diagnosis compared to patients with health insurance. Compared to White patients, Black (OR 0.63, 95% CI 0.47 to 0.85) and Asian/Pacific Islander (OR 0.65, 95% CI 0.46 to 0.91) were less likely to undergo surgery. In addition, Black patients were less likely to receive chemotherapy (OR 0.67, 95% CI 0.49 to 0.91) compared to White patients. In patients with chondrosarcoma, those with Medicaid had worse OS compared to patients with insurance (hazard ratio (HR) 1.65, 95% CI 1.06 to 2.56).

Conclusion

In patients with a bone sarcoma, the cancer stage at diagnosis varied based on insurance status, and racial disparities were identified in treatment. Further studies are needed to identify modifiable factors which can mitigate socioeconomic and racial disparities found in patients with bone sarcomas.

Cite this article: Bone Joint Res 2022;11(5):278–291.

Prognostic significance and therapeutic potentials of immune checkpoints in osteosarcoma

Although there exist manifold strategies for cancer treatment, researchers are obliged to develop novel treatments based on the challenges that arise. One of these recent treatment approaches is cancer immunotherapy, which enjoys various types of strategies itself. However, one of the most significant methods, in this regard, is employing immune checkpoint proteins (ICPs). Bone sarcomas have several subtypes, with the most common ones being chordoma, chondrosarcoma, Ewing sarcoma, and osteosarcoma. Although many aggressive treatment approaches, including radiotherapy, chemotherapy, and surgical resection, have been employed over the last decades, significantly improved outcomes have not been observed for Ewing sarcoma or osteosarcoma patients. Additionally, chordoma and chdrosarcoma resist against both radiation and chemotherapy. Accordingly, elucidating how recent therapies could affect bone sarcomas is necessary. Checkpoint inhibitors have attracted great attention for the treatment of several cancer types, including bone sarcoma. Herein, the recent advances of current immune checkpoint targets, such as anti-PD-1/PD-L1 and anti-CTLA-4 blockade, for the treatment of bone sarcoma have been reviewed.

Diffusion kurtosis imaging assessment of the response to radiotherapy in a VX2 bone tumor model: an animal study

BACKGROUND

Neoadjuvant radiotherapy plays a vital role in the treatment of malignant bone tumors, and non-invasive imaging methods are needed to evaluate the response to treatment.

PURPOSE

To assess the value of diffusion kurtosis imaging (DKI) for monitoring early response to radiotherapy in malignant bone tumors.

MATERIAL AND METHODS

Treatment response was evaluated in a rabbit VX2 bone tumor model (n = 35) using magnetic resonance imaging (MRI), DKI, and histopathologic examinations. Subjects were divided into three groups: pre-treatment, post-treatment, and control groups. The post-treatment group was subclassified into good response and poor response groups according to the results of histopathologic examination. Apparent diffusion coefficient (ADC) and DKI parameters (mean diffusion coefficient [MD] and mean kurtosis [MK]) were recorded. The relationship between ADC, DKI parameters, and histopathologic changes after radiotherapy was determined using Pearson's correlation coefficient. The diagnostic performance of these parameters was assessed using receiver operating characteristic analysis.

RESULTS

MD in the good response group was higher after treatment than before treatment (P < 0.001) and higher than that in the poor response group (P = 0.009). MD was highly correlated with tumor cell density and apoptosis rate (r = -0.771, P < 0.001 and r = 0.625, P < 0.001, respectively). MD was superior to other parameters for determining the curative effect of radiotherapy, with a sensitivity of 75.0%, specificity of 100.0%, and area under the curve of 0.917 (P < 0.001).

CONCLUSION

The correlations between MD, tumor cell density, and apoptosis suggest that MD could be useful for assessing the early response to radiotherapy in rabbit VX2 malignant bone tumors.

The Clinical Significance of miR-21 in Guiding Chemotherapy for Patients with Osteosarcoma

Objective

The present study aims to explore the correlation between osteosarcoma (OS) chemosensitivity and the expression levels of serum and tumor tissue micro-ribonucleic acid-21 (miR-21).

Methods

The relevant miR-21 expression levels in 30 patients with OS were detected, and the gender, age, tumor location, pathological type, Enneking stage, and miR-21 expression changes before and after chemotherapy were retrospectively analyzed.

Results

Serum and tumor tissue miR21 expression levels were significantly higher in patients with OS than in control subjects; the serum miR-21 expressions before and after chemotherapy were not related to patient age and gender. The effective chemotherapy group showed significant differences in miR-21 expression levels before and after chemotherapy.

Conclusion

Serum and tumor tissue miR-21 expression levels in patients with OS are closely related to the effects of chemotherapy, making miR-21 a potential biomarker and therapeutic target for the diagnosis and evaluation of chemotherapy effects on patients with OS.

The role of percutaneous transarterial embolization in the management of spinal bone tumors: a literature review

PURPOSE

Spinal bone tumors include a heterogeneous broad of primary or metastatic lesions that may present as incidental findings or manifest with painful symptoms and pathological fractures. Optimal management of spine bone lesions is often difficult and treatment algorithms are usually solidly based on surgery. We aimed to evaluate the contribution of trans-arterial embolization in this field, with particular attention to the procedure efficacy, technical difficulties and complications.

METHODS

We present a literature review on the role of trans-arterial embolization in the management of spinal bone tumors, both primary and metastatic, evaluating its contribution as preoperative treatment, palliative procedure and standalone curative strategy.

RESULTS

Trans-arterial embolization provides an important contribution to reducing surgery hemorrhagic risks, offering a better visualization of the operating field, and possibly increasing tumor susceptibility to chemotherapy or radiation therapy. Nonetheless, it plays an important part in pain palliation, with the unquestionable advantage of being easily repeatable in case of necessity. Its curative role as a standalone therapy is still subject of debate, and at the present time, satisfactory results have been recorded only in the treatment of aneurysmal bone cysts.

CONCLUSION

Percutaneous trans-arterial embolization has established as a highly useful minimally invasive procedure in the management of spinal bone lesions, particularly as adjuvant preoperative therapy and palliative treatment.

The Bateman-Type Soft Tissue Reconstruction around Proximal or Total Humeral Megaprostheses in Patients with Primary Malignant Bone Tumors-Functional Outcome and Endoprosthetic Complications

We aimed to evaluate the functional outcome and endoprosthetic complications following the Bateman-type soft tissue reconstruction around proximal or total humeral replacements in patients undergoing resection of a primary malignant bone tumor. Between September 2001 and December 2018, a total of 102 patients underwent resection of a primary malignant bone tumor and subsequent reconstruction with a modular humeral megaprosthesis in our department. Fifteen (15%) of these patients underwent a Bateman-type soft tissue reconstruction and were included in this retrospective study. The median Musculoskeletal Tumor Society (MSTS) score was 21, the median Toronto Extremity Salvage Score (TESS) was 70, and the median American Shoulder and Elbow Surgeons (ASES) score was 72. Fifty-three percent (8/15) of all patients required a revision surgery after a median time of 6 months. There were 2 soft tissue failures, 3 infections and 3 tumor recurrences. The revision-free implant survivorship amounted to 53% (95% confidence interval (CI) 28-81) after 1 year and 47% (95% CI 22-73) at last follow-up. The Bateman-type reconstruction is a feasible option for soft tissue reconstruction but functional outcome is overall limited and the risk for revision surgery within the first postoperative year is high.

Suicide and accidental deaths among patients with primary malignant bone tumors

Background

It has been recognized that cancer is associated with a higher risk of suicide or accidental death. Earlier studies have evidenced that patients with malignant bone tumors usually experience psychological dysfunction and physical disability following surgery, which are shared risk factors between suicidal and accidental deaths. To our knowledge, there is no large population-based study on the risk of suicide or accidental death among patients with malignant bone tumors.

Questions/purposes

This study aimed to determine whether patients with primary malignant bone tumors are at a higher risk of suicide and accidental death than the general population and to identify the demographic and tumour-related characteristics and type of surgery associated with a higher risk of suicide and accidental death among these patients.

Methods

Overall, 50,817 patients diagnosed with primary malignant bone tumors between 1973 and 1975 were identified from the Surveillance, Epidemiology, and End Results database. The standardised mortality ratio (SMR) was calculated based on the general population's mortality data, gathered by the National Center for Health Statistics. The Cox regression model was developed to determine risk factors associated with a higher risk of suicide and accidental death.

Results

Patients with primary malignant bone tumors had a higher risk of suicide and accidental death than the general population in the United States (US) (SMR = 2.17; 95% confidence interval (CI) [1.80-2.62] and SMR = 1.73; 95% CI [1.54-1.95]). Compared with limb salvage, amputation significantly increased the risk of suicide (SMR = 3.99; 95% CI [2.52-6.34], hazard ratio (HR) = 2.32; 95% CI [1.31-4.09]; P < 0.01) but did not increase the risk of accidental death (SMR = 1.61; 95% CI [1.07-2.42], HR = 1.11; 95% CI [0.71-1.74]; P = 0.65). Higher suicide risk was observed among older patients whose age at diagnosis was more than 60 years (HR = 4.04; 95% CI [1.98-8.26]; P < 0.001), males (HR = 3.48; 95% CI [2.16-5.62]; P < 0.001), and whites (HR = 3.71; 95% CI [1.17-11.73]; P < 0.001). The risk of suicide and accidental death was highest in the first year after diagnosis (SMR = 2.95; 95% CI [1.86-4.69] and SMR = 2.02; 95% CI [1.48-2.74]).

Conclusion

We first reported that patients with primary malignant bone tumors had a higher risk of suicide and accidental death than the general US population. Therefore, clinicians should pay more attention to the psychological status, physical function, and cognitive level of these survivors.

Role of cancer stem cells in the development of giant cell tumor of bone

The primary bone tumor is usually observed in adolescence age group which has been shown to be part of nearly 20% of the sarcomas known today. Giant cell tumor of bone (GCTB) can be benign as well as malignant tumor which exhibits localized dynamism and is usually associated with the end point of a long bone. Giant cell tumor (GCT) involves mononuclear stromal cells which proliferate at a high rate, multinucleated giant cells and stromal cells are equally present in this type of tumor. Cancer stem cells (CSCs) have been confirmed to play a potential role in the development of GCT. Cancer stem cell-based microRNAs have been shown to contribute to a greater extent in giant cell tumor of bone. CSCs and microRNAs present in the tumors specifically are a great concern today which need in-depth knowledge as well as advanced techniques to treat the bone cancer effectively. In this review, we attempted to summarize the role played by cancer stem cells involving certain important molecules/factors such as; Mesenchymal Stem Cells (MSCs), miRNAs and signaling mechanism such as; mTOR/PI3K-AKT, towards the formation of giant cell tumor of bone, in order to get an insight regarding various effective strategies and research advancements to obtain adequate knowledge related to CSCs which may help to focus on highly effective treatment procedures for bone tumors.

Lycorine exerts antitumor activity against osteosarcoma cells in vitro and in vivo xenograft model through the JAK2/STAT3 pathway

Background: Lycorine, a natural alkaloid, has been indicated to have various physiological effects, including a potential effect against cancer. However, the anticancer effect of lycorine on osteosarcoma (OS) and the detailed molecular mechanisms involved remain unclear.

Purpose: The purpose of this study was to examine the effect of lycorine on human OS and elucidated it underlying mechanisms

Materials and methods: In vitro assays, OS cells were treated with lycorine at various concentrations. Then the cell proliferation, colony formation, cell cycle distribution, apoptosis, migration and invasion were assayed to detect the anticancer effect of lycorine on OS cell lines. Western blotting analysis was used to verify the expression of related proteins. In addition, the mouse xenograft model was performed to evaluate lycorine’s therapeutic potential on OS in vivo.

Results: The in vitro results demonstrated that lycorine induced apoptosis and cell cycle arrest and suppressed the migration and invasion by suppressing constitutive signal transducers and activators of transcription 3 (STAT3) activation through enhancing the expression of SH2 domain-containing phosphatase 1 (SHP-1) and downregulating the expression of STAT3 target proteins. Moreover, our mouse xenograft model revealed that lycorine inhibited the tumor growth in vivo.

Conclusion: These results demonstrated that the anti-OS effects of lycorine were at least partly due to the suppression of the Janus kinase 2/signal transducers and activators of transcription 3 (JAK2)/STAT3 pathway. Taken together, these results indicate that lycorine possesses the potential to be a promising candidate in clinical therapy for human OS in the future.

Metachronous extraskeletal (soft tissue) epithelioid osteogenic sarcoma: a case report

Background

Metachronous osteosarcoma is a rare form of osteosarcoma. The occurrence of metachronous tumor in soft tissue is exceedingly rare. The pathogenesis of metachronous osteosarcoma, as to whether it represents multiple true primaries or metastatic disease, is still obscure.

Case presentation

A 49-year-old Indian man presented with progressively increasing swelling in his left hand of 2 months’ duration. An X-ray showed a soft tissue lesion. Contrast-enhanced computed tomography showed a soft tissue mass lesion, with peripheral enhancement and central necrotic areas in radial palmar soft tissue overlying second metacarpophalangeal region with no obvious bony osteolysis. Possibilities of acute abscess, resolving hematoma, or aggressive soft tissue mass lesion were suggested. An incision biopsy showed morphological features of epithelioid osteosarcoma, which was confirmed on immunohistochemistry. A detailed history revealed that our patient was diagnosed as having osteosarcoma of his right leg 3 years previously. Based on history, radiology, morphology, and immunohistochemistry, a final diagnosis of extraskeletal (soft tissue) epithelioid osteogenic sarcoma of the left hand occurring as a metachronous tumor 3 years after diagnosis of primary osteosarcoma in the right leg was given.

Conclusion

This is probably the first reported case of extraskeletal (soft tissue) epithelioid osteosarcoma occurring as a metachronous tumor 3 years after diagnosis of primary osteosarcoma in the right leg. The prognosis of metachronous skeletal osteosarcoma is poor as compared to that of relapse limited to lungs. In late metachronous osteosarcoma, combined-modality therapy comprising surgery and aggressive chemotherapy may affect long-term survival. Lifelong follow-up of surviving patients with osteosarcoma is necessary and if metachronous osteosarcoma is discovered, it should be treated with curative intent.

Electronic supplementary material

The online version of this article (10.1186/s13256-019-2070-3) contains supplementary material, which is available to authorized users.

Diagnostic efficacy of PET/CT in bone tumors

Clinical value of PET/CT (positron emission tomography/computed tomography) in the diagnosis of malignant bone tumors (BT) was investigated. Fifty-four patients with BT were first diagnosed by ordinary CT and then by PET/CT. The diagnostic efficacy outcomes and diagnosis of malignant BT by clinical stage of the two methods for BT were observed and recorded, and the diagnostic value of PET/CT in the diagnosis of BT was evaluated. There were 14 cases of benign BT patients, 15 cases of stage I, 10 cases of stage II and 15 cases of stage III in malignant BT patients. The diagnostic coincidence rate of PET/CT was 92.59% and the diagnostic coincidence rate of CT was 72.22%, which showed that the diagnostic coincidence rate of PET/CT was significantly higher than that of CT (P<0.05). The sensitivity, negative predictive value and positive predictive value of PET/CT were 95.00, 85.71 and 95.00%, respectively, which were higher than those of CT (P<0.05). CT and PET/CT were used for the clinical staging and pathological diagnosis of malignant BT; the results showed that the diagnostic accuracy of PET/CT in the clinical stages of malignant BT was also significantly higher than that of CT (P<0.05). The diagnostic efficacy of PET/CT in BT is better than that in CT. PET/CT can diagnose the pathological properties of BT more accurately, and can also effectively diagnose the clinical stage of malignant BT and provide clinical diagnostic basis for follow-up procedures.

Association between TP53 rs1042522 gene polymorphism and the risk of malignant bone tumors: a meta-analysis

TP53 is a tumor suppressor gene which is essential for regulating cell division and preventing tumor formation. Several studies have assessed the associations of TP53 single-nucleotide polymorphisms (SNP) with susceptibility of malignant bone tumors, including osteosarcoma and Ewing sarcoma, but the results are inconsistent. In the present meta-analysis, we aimed to elucidate the associations of TP53 rs1042522 genetic polymorphism with the risk of osteosarcoma or Ewing sarcoma. We systematically searched Medline, PubMed, Web of Science, Embase, and the Cochrane Library databases. Eligible studies assessing the polymorphisms in the TP53 rs1042522 gene and risk of malignant bone tumors were incorporated. The pooled odds ratio (OR) with its 95% confidence intervals (95% CIs) were used to assess these possible associations. Five studies with a total of 567 cases and 935 controls were finally included the meta-analysis. Meta-analysis of TP53 rs1042522 polymorphism was significantly associated with an increased risk of malignant bone tumors (G versus C: OR = 1.27, 95% CI 1.08–1.50, P=0.005; GG versus GC/CC: OR = 1.55, 95% CI 1.21–2.00, P=0.001). Moreover, in a stratified analysis, a statistically significant correlation between this SNP and osteosarcoma risk was also observed. Our results suggest that there are significant associations of TP53 rs1042522 polymorphism with malignant bone tumors risk. More studies based on larger sample sizes and homogeneous samples are warranted to confirm these findings.

Overexpression of Notch3 is associated with metastasis and poor prognosis in osteosarcoma patients

Background

Notch signaling abnormalities are associated with the development of various tumors, including hematopoietic and epithelium-derived tumors. However, the role of Notch signaling in tumors originating from mesenchymal cells is unclear. The effect of Notch3 expression on the prognosis of osteosarcoma and its role and mechanism in osteosarcoma cells have never been reported.

Materials and methods

In this study, we performed a clinicopathological analysis of 70 cases of osteosarcoma, with primary focus on survival. Osteosarcoma cell lines MTH and U2OS were used. After knockdown of Notch3 by lentiviral transfection and siRNA, the cell cycle, cell viability, and wound healing capacity were assessed. Subsequently, the Transwell assay was performed, and the expression levels of hairy and enhancer of split-1 (Hes1) and matrix metalloproteinase 7 (MMP7) were detected by RT-PCR and Western blot assay. The expression of MMP7 was also detected after knockdown of Hes1. Animal experiments were performed by injecting the cell lines MTH of Notch3 knockdown into mice tail veins and comparing the development of lung metastasis with the control group.

Results

Comparison of survival curves showed that Notch3 expression significantly impacts patient survival. Additionally, multivariate analysis revealed that Notch3 is an independent prognostic factor for osteosarcoma. In in vivo experiments, osteosarcoma-associated pulmonary metastasis in nude mice was reduced after Notch3 silencing. The expression of downstream effector molecule, Hes1, and that of the invasion and metastasis-associated proteolytic enzyme, MMP7, were reduced, and MMP7 was further decreased by Hes1 knockdown in in vitro experiments.

Conclusion

Notch3 is a prognostic factor for osteosarcoma and might regulate its invasion and metastasis through the downstream target gene Hes1 and effector MMP7.

Prognostic significance of matrix metalloproteinase 9 expression in osteosarcoma: A meta-analysis of 16 studies

BACKGROUND

Matrix metalloproteinase 9 (MMP-9) is significant in the progression of osteosarcoma (OS) via increasing tumor growth, invasion and metastasis. Although previous reports indicate the prognostic value of MMP-9 in OS, there is still a great degree on inconsistency between studies. Here we report a comprehensive evaluation of the value of MMP-9 in metastasis of OS by conducting a meta-analysis of published studies.

METHODS

The quantity of the studies was evaluated using the Newcastle-Ottawa quality assessment scale (NOS). Sixteen studies with a total of 816 patients with OS were examined and we calculated the pooled odds ratio (OR) with corresponding 95% confidence interval (CI) (95% CI) to evaluate that the positive expression of MMP-9 predicts neoplasm metastasis and poor survival in OS.

RESULTS

The results of Meta-analysis indicated that patients with positive expression of MMP-9 were significantly associated with neoplasm metastasis (OR = 4.69, 95% CI: 3.05-7.21, P <.001) and poor survival in OS with the pooled OR of 7.19 (95% CI 4.32-11.98, P <.001) when compared to their counterparts with a negative expression of MMP-9. The results of sensitivity analysis showed that the pooled OR was stable. It doesn't significantly change when a single study was removed.

CONCLUSIONS

The results of meta-analysis indicated that MMP-9 may be a prognostic biomarker guiding the clinical therapy for OS.

Variants in the 14q32 miRNA cluster are associated with osteosarcoma risk in the Spanish population

Association studies in osteosarcoma risk found significant results in intergenic regions, suggesting that regions which do not codify for proteins could play an important role. The deregulation of microRNAs (miRNAs) has been already associated with osteosarcoma. Consequently, genetic variants affecting miRNA function could be associated with risk. This study aimed to evaluate the involvement of all genetic variants in pre-miRNAs described so far in relationship to the risk of osteosarcoma. We analyzed a total of 213 genetic variants in 206 pre-miRNAs in two cohorts of osteosarcoma patients (n = 100) and their corresponding controls (n = 256) from Spanish and Slovenian populations, using Goldengate Veracode technology (Illumina). Four polymorphisms in pre-miRNAs at 14q32 miRNA cluster were associated with osteosarcoma risk in the Spanish population (rs12894467, rs61992671, rs58834075 and rs12879262). Pathway enrichment analysis including target genes of these miRNAs pointed out the WNT signaling pathways overrepresented. Moreover, different single nucleotide polymorphism (SNP) effects between the two populations included were observed, suggesting the existence of population differences. In conclusion, 14q32 miRNA cluster seems to be a hotspot for osteosarcoma susceptibility in the Spanish population, but not in the Slovenian, which supports the idea of the existence of population differences in developing this disease.

Regulatory effects of microRNA‑184 on osteosarcoma via the Wnt/β‑catenin signaling pathway

The present study aimed to investigate the role of microRNA (miRNA/miR)‑184 in osteosarcoma growth, development and metastasis, and the effects of miRNA‑184 on the proliferation, invasion and metastasis of osteosarcoma cells and associated mechanisms. In vitro, miR‑184 was transfected into U‑2OS cells and 143B cells. Reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR) was used to detect the expression of miR‑184. MTT was utilized to detect cell proliferation. A Transwell assay was applied to detect cell invasiveness. In vivo, an osteosarcoma tibial orthotopic metastatic tumor model was established, and western blotting and RT‑qPCR were used to detect the expression of Wnt and β‑catenin. Following the overexpression of miR‑184, the proliferation and cell invasion ability were significantly increased in U‑2OS and 143B cells. Following inhibition of miR‑184, cell proliferation and cell invasion ability were significantly decreased. In nude mice, tumor volume significantly increased following overexpression of miR‑184, and Wnt and phosphorylated β‑catenin levels were significantly increased. Following miR‑184 inhibition, tumor volume was significantly decreased, and Wnt and phosphorylated β‑catenin levels were significantly decreased. The results of the present study indicated that the Wnt/β‑catenin signaling pathway serves a key function in the mechanism of osteosarcoma. Inhibition of miRNA‑184 may reduce tumor volume of osteosarcoma via regulation of the Wnt/β‑catenin signaling pathway and may provide a novel strategy for the future diagnosis and treatment of osteosarcoma.

Meta-analysis of clinical significance of p53 protein expression in patients with osteosarcoma

AIM

The prognostic role of p53 protein expression in osteosarcoma has been reported, but the results remain conflicting.

MATERIALS & METHODS

The relevant literature databases were searched to get eligible articles published in English. The overall ORs or HRs and their corresponding 95% CIs were calculated.

RESULTS

The results indicated that p53 protein expression was not linked to age factor, gender, tumor grade, cancer metastasis and response to chemotherapy. p53 expression was significantly lower in osteogenic osteosarcoma than in nonosteogenic osteosarcoma (OR = 0.40; p = 0.006). p53 expression was associated with a poor prognosis of patients in overall survival (univariate analysis: HR: 2.49; p < 0.001 and multivariate analysis: HR: 2.92; p < 0.001).

CONCLUSION

p53 expression was correlated with pathological type and may become a useful prognostic biomarker in overall survival in osteosarcoma.

Effect of entinostat on NK cell-mediated cytotoxicity against osteosarcoma cells and osteosarcoma lung metastasis

There is a crucial need for a new therapeutic approach for osteosarcoma (OS) lung metastasis since this disease remains the main cause of mortality in OS. We previously demonstrated that natural killer (NK) cell therapy has minimal efficacy against OS metastasis. This study determined whether the histone deacetylase inhibitor entinostat could immunosensitize OS cells to NK cell lysis and increases the efficacy of NK cell therapy for OS lung metastasis. Entinostat upregulated ligands for NK cell-activating receptors (major histocompatibility complex [MHC] class I polypeptide-related chain A [MICA] and B [MICB]; UL16 binding proteins 1, 2, 5, and 6; and CD155) on OS cells both in vitro and in vivo and led to more susceptibility to NK cell-mediated cytotoxicity in vitro. Importantly, entinostat did not change NK cell viability, receptor expression, or function within the 24-h treatment. We also demonstrated two potential mechanisms by which entinostat enhanced expression of MICA and MICB on OS cells. Although entinostat upregulated ligands for the NK cell activating receptor on OS lung metastasis, it failed to augment the efficacy of NK cell therapy in our nude mouse human OS lung metastasis model. This can be partly explained by our finding that although the infused NK cells were active and functional and could penetrate into the lungs, they failed to infiltrate into the lung nodules. These challenges regarding cellular immunotherapy against solid tumors may be overcome by combination therapy, such as adding a NK cell-activating cytokine (IL-2 or IL-21).

Modeling osteosarcoma progression by measuring the connectivity dynamics using an inference of multiple differential modules algorithm

Understanding the dynamic changes in connectivity of molecular pathways is important for determining disease prognosis. Thus, the current study used an inference of multiple differential modules (iMDM) algorithm to identify the connectivity changes of sub-network to predict the progression of osteosarcoma (OS) based on the microarray data of OS at four Huvos grades. Initially, multiple differential co-expression networks (M-DCNs) were constructed, and weight values were assigned for each edge, followed by detection of seed genes in M-DCNs according to the topological properties. Using these seed gene as a start, an iMDM algorithm was utilized to identify the multiple candidate modules. The statistical significance was determined to select multiple differential modules (M-DMs) based on the null score distribution of candidate modules generated using randomized networks. Additionally, the significance of Module Connectivity Dynamic Score (MCDS) to quantify the dynamic change of M-DMs connectivity. Further, DAVID was employed for KEGG pathway enrichment analysis of genes in dynamic modules. In addition to the basal condition, four conditions, OS grade 1–4, were also included (M=4). In total, 4 DCNs were constructed, and each of them included 2,138 edges and 272 nodes. A total of 13 genes were identified and termed ‘seed genes’ based on the z-score distribution of 272 nodes in DCNs. Following the module search, module refinement and statistical significance analysis, a total of four 4-DMs (modules 1, 2, 3 and 4) were identified. Only one significant 4-DM (module 3 in the DCNs of grade 1, 2, 3 and 4 OS) with dynamic changes was detected when the MCDS of real 4-DMs were compared to a null distribution of MCDS of random 4-DMs. Notably, the genes of the dynamic module (module 3) were enriched in two significant pathway terms, ubiquitin-mediated proteolysis and ribosome. The seed genes with the highest degrees included protein phosphatase 1 regulatory subunit 12A (PPP1R12A), UTP3, small subunit processome component homolog (UTP3), prostaglandin E synthase 3 (PTGES3). Thus, pathway functions (ubiquitin-mediated proteolysis and ribosome) and several seed genes (PPP1R12A, UTP3, and PTGES3) in the dynamic module 3 may be associated with the progression of OS and may serve as potential therapeutic targets in OS.

P16 protein expression as a useful predictive biomarker for neoadjuvant chemotherapy response in patients with high-grade osteosarcoma: A systematic meta-analysis under guideline of PRISMA

BACKGROUND

Neoadjuvant chemotherapy for patients with high-grade osteosarcoma has highly improved the clinical survival. However, the prognostic and predictive role of P16 expression after neoadjuvant chemotherapy remains unclear. We first determined whether P16 expression can become a potential prognostic and predictive biomarker in high-grade osteosarcoma.

METHODS

This meta-analysis was conducted based on the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guideline. Eligible studies were pooled and the overall odds ratios (ORs) and hazard ratios (HRs) with the corresponding 95% confidence intervals (95% CIs) were calculated in this analysis.

RESULTS

Four studies involving a total of 527 patients with high-grade osteosarcoma receiving neoadjuvant chemotherapy were identified. We did not find that P16 expression was correlated with sex status, histologic subtype, and tumor site (P > .1). P16 expression was found to be significantly associated with a "good" response to neoadjuvant chemotherapy (OR = 4.69, P < .001). A significant relationship was observed between p16 expression and pathologic complete response after neoadjuvant chemotherapy using multivariate analysis (OR = 9.63, P = .001). The expression of the P16 was not associated with clinical outcomes in overall survival (OS) and disease-free survival (DFS) by multivariate analysis (OS: P = .448; DFS: P = .263).

CONCLUSIONS

The use of P16 expression could become a promising predictive biomarker of the response to neoadjuvant chemotherapy in the white population with high-grade osteosarcoma. However, it was not correlated with the prognosis of patients in OS and DFS. More clinical researches are very essential in Asians in the future.

Prognostic significance of chemotherapy-induced necrosis in osteosarcoma patients receiving pasteurized autografts

Background

Among various reconstruction methods after wide excision for osteosarcoma, pasteurized autograft is often preferred. While the whole area of the tumor can be assessed for chemotherapy-induced necrosis, one of the important prognostic factors, in other reconstructive techniques, only a portion removed from a wide-resection specimen is available when using pasteurized autograft method. The assessment, therefore, may be unreliable. We analyzed the prognostic significance of the chemotherapy-induced necrosis in osteosarcoma patients who underwent reconstruction with pasteurized autografts.

Patients and methods

We reviewed the records of osteosarcoma patients who underwent treatment in our institution from 1998 to 2013. Cases of reconstruction with pasteurized autografts were defined as the patient group, and the same number of patients who underwent other reconstruction methods served as controls. Chemotherapy-induced necrosis was evaluated for removed extra-osseous and curetted intramedullary tumor tissues.

Results

A total of 22 patients were identified; the median age was 15.5 years, and there were 12 males. The most common tumor location was the distal femur. The most common histological subtype was osteoblastic. Median size was 8.1 cm. Disease status was stage IIB in 13 patients and IIA in 9. Median follow-up was 76 months. No differences between the patient and control groups were observed in potential prognostic factors, overall survival, metastasis-free survival, or recurrence-free survival. Univariate analyses demonstrated that histological response was a significant prognostic factor for metastasis-free survival and also significant for recurrence-free survival.

Conclusion

Chemotherapy-induced necrosis grading, using only available tumor tissues, could be a prognostic factor for osteosarcoma patients receiving pasteurized autografts for reconstructive surgery.

Downregulation of microRNA-497 is associated with upregulation of synuclein γ in patients with osteosarcoma

The present study aimed to investigate the effects of microRNA (miRNA/miR)-497 expression levels on the expression levels of synuclein γ (SNCG) in serum samples, as well as osteosarcoma and lung-metastatic tissue samples, from patients with osteosarcoma. Between December 2010 and August 2013, fasting peripheral blood was collected from 36 patients with osteosarcoma for serum separation. In addition, osteosarcoma and lung metastatic tissues were resected from 15 osteosarcoma patients with lung metastasis by surgery. Bioinformatics was employed to predict the amount miRNA that binds to SNCG. Reverse transcription-quantitative polymerase chain reaction was used to determine the expression levels of SNCG and miR-497, and western blotting was performed to determine protein expression levels. It was observed that SNCG mRNA and protein expression levels were significantly upregulated in osteosarcoma tissues (P<0.01). Additionally, SNCG mRNA (P<0.01) and protein (P<0.05) expression levels were significantly upregulated in the blood of patients with osteosarcoma. SNCG mRNA and protein expression levels were also significantly upregulated in lung metastatic tissues (P<0.01). miR-497 was significantly downregulated in all three samples; therefore downregulation of miR-497 may lead to the occurrence, development and metastasis of osteosarcoma through the upregulation of SNCG mRNA. In summary, the upregulation of SNCG in blood, osteosarcoma tissue and lung metastatic tissue samples is associated with the dowregulation of miR-497, suggesting that miR-497 may be a potential marker and therapeutic target for the treatment of osteosarcoma.

A systematic review and meta-analysis of MDM2 polymorphisms in osteosarcoma susceptibility

Two polymorphisms in the murine double minute 2 (MDM2) gene (rs1690916 and rs2279744) have been associated with the risk of osteosarcoma (OS). When we analyzed these two polymorphisms in two new independents cohorts (Spanish and Slovenian), we found no association. In order to clarify this, we conducted a meta-analysis including six populations, with a total of 246 OS patients and 1,760 controls for rs1690916; and 433 OS patients and 1,959 controls for rs2279744. Pooled odds ratio risks and corresponding 95% CI were estimated to assess the possible associations. Our results showed that these two polymorphisms were not associated with the susceptibility of OS under any genetic model studied. In conclusion, the present meta-analysis indicates that MDM2 rs1690916 and rs2279744 cannot be considered as genetic risk factors for OS susceptibility in the different populations. Therefore, the influence of these two polymorphisms on the risk of OS may be less important than previously suggested. Future studies are needed to confirm these results.

Prognostic role of hypoxia-inducible factor-1 alpha expression in osteosarcoma: a meta-analysis

Background

Hypoxia-inducible factor-1α (HIF-1α) plays an important role in tumor progression and metastasis. A number of studies have investigated the association of HIF-1α with prognosis and clinicopathological characteristics of osteosarcoma but yielded inconsistent results.

Method

Systematic computerized searches were performed in PubMed, Embase, and Web of Science databases for relevant original articles. The pooled hazard ratios (HRs) and odds ratios (ORs) with corresponding confidence intervals (CIs) were calculated to assess the prognostic value of HIF-1α expression. The standard mean difference was used to analyze the continuous variable.

Results

Finally, nine studies comprising 486 patients were subjected to final analysis. Protein expression level of HIF-1α was found to be significantly related to overall survival (HR =3.0; 95% CI: 1.46–6.15), disease-free survival (HR =2.23; 95% CI: 1.26–3.92), pathologic grade (OR =21.33; 95% CI: 4.60–98.88), tumor stage (OR =10.29; 95% CI: 3.55–29.82), chemotherapy response (OR =9.68; 95% CI: 1.87–50.18), metastasis (OR =5.06; 95% CI: 2.87–8.92), and microvessel density (standard mean difference =2.83; 95% CI: 2.28–3.39).

Conclusion

This meta-analysis revealed that overexpression of HIF-1α is a predictive factor of poor outcomes for osteosarcoma. HIF-1α appeared to play an important role in prognostic evaluation and may be a potential target in antitumoral therapy.

Understanding the Osteosarcoma Pathobiology: A Comparative Oncology Approach

Osteosarcoma is an aggressive primary bone tumor in humans and is among the most common cancer afflicting dogs. Despite surgical advancements and intensification of chemo- and targeted therapies, the survival outcome for osteosarcoma patients is, as of yet, suboptimal. The presence of metastatic disease at diagnosis or its recurrence after initial therapy is a major factor for the poor outcomes. It is thought that most human and canine patients have at least microscopic metastatic lesions at diagnosis. Osteosarcoma in dogs occurs naturally with greater frequency and shares many biological and clinical similarities with osteosarcoma in humans. From a genetic perspective, osteosarcoma in both humans and dogs is characterized by complex karyotypes with highly variable structural and numerical chromosomal aberrations. Similar molecular abnormalities have been observed in human and canine osteosarcoma. For instance, loss of TP53 and RB regulated pathways are common. While there are several oncogenes that are commonly amplified in both humans and dogs, such as MYC and RAS, no commonly activated proto-oncogene has been identified that could form the basis for targeted therapies. It remains possible that recurrent aberrant gene expression changes due to gene amplification or epigenetic alterations could be uncovered and these could be used for developing new, targeted therapies. However, the remarkably high genomic complexity of osteosarcoma has precluded their definitive identification. Several advantageous murine models of osteosarcoma have been generated. These include spontaneous and genetically engineered mouse models, including a model based on forward genetics and transposon mutagenesis allowing new genes and genetic pathways to be implicated in osteosarcoma development. The proposition of this review is that careful comparative genomic studies between human, canine and mouse models of osteosarcoma may help identify commonly affected and targetable pathways for alternative therapies for osteosarcoma patients. Translational research may be found through a path that begins in mouse models, and then moves through canine patients, and then human patients.

Changes in the body image of bone sarcoma survivors following surgical treatment--A qualitative study

Background and Objectives

Among several long‐term effects, people treated for cancer may experience an altered appearance. Our study aims to identify how visible body changes following surgical treatment affect the life and identity of primary bone sarcoma survivors 3–10 years after diagnosis. A qualitative, phenomenological, and hermeneutic design was applied.

Methods

Sarcoma survivors (n = 18) who were previously treated at Norwegian Radium Hospital, Oslo University Hospital, participated in the study. In‐depth and semi‐structured interviews were conducted and analyzed using inductive thematic analysis.

Results

The main finding of this study concerned how altered appearance after bone cancer treatment in the hip/pelvis or lower extremities affected the participants’ self‐esteem. Half of the participants expressed concerns about their visible differences, particularly those with functional impairment. They felt that it is important to hide the bodily signs of changes to appear as normal as possible, as well as attractive and healthy. They describe, with specific examples, how these changes influence their self‐realization, especially their social life.

Conclusions

Healthcare providers who guide bone sarcoma survivors during follow‐up should develop a comprehensive understanding of what it means to cope with a changed and challenging body. J. Surg. Oncol. 2016;113:229–234. © 2015 The Authors. Journal of Surgical Oncology Published by Wiley Periodicals, Inc.

Silencing of Eag1 Gene Inhibits Osteosarcoma Proliferation and Migration by Targeting STAT3-VEGF Pathway

So far, the role of Ether à go-go 1 (Eag1) potassium channels in migration and invasion progression of cancers remains elusive. In the present study, the effects of Eag1 knockdown on osteosarcoma cell proliferation, growth, and apoptosis were examined. Then, we evaluated the effects of Eag1 silencing on osteosarcoma cell migration and invasion. In addition, we detected the expression of vascular endothelial growth factor (VEGF) and signal transducer and activator of transcription 3 (STAT3) in osteosarcoma cell treated with Eag1 small interfering RNAs (siRNAs). Finally, STAT3 siRNA was employed to determine the influence of downregulation of STAT3 on cell proliferation and migration. The results showed that knockdown of Eag1 significantly suppressed osteosarcoma cell proliferation and osteosarcoma xenografts growth. However, Eag1 silencing had little effect on cell apoptosis. Additionally, osteosarcoma cell adhesion, migration, and invasion were also potently attenuated. Notably, the expression levels of VEGF decreased evidently upon Eag1 siRNAs treatment, paralleled with reductions in the expression levels of STAT3. Moreover, a similar pattern was observed in osteosarcoma cell proliferation and migration suppression between STAT3 siRNA and Eag1 siRNAs groups. Our data indicated that Eag1 promotes osteosarcoma proliferation and migration, at least in part, by targeting STAT3-VEGF pathway.

Prognostic Significance of Serum Alkaline Phosphatase Level in Osteosarcoma: A Meta-Analysis of Published Data

Background. Serum alkaline phosphatase (SALP) is commonly elevated in osteosarcoma patients. A number of studies have investigated the prognostic role of SALP level in patients with osteosarcoma but yielded inconsistent results. Method. Systematic computerized searches were performed in PubMed, Embase, and Web of Science databases for relevant original articles. The pooled hazard ratios (HRs) and relative risks (RRs) with corresponding confidence intervals (CIs) were calculated to assess the prognostic value of SALP level. Results. Finally, 21 studies comprising 3228 patients were included. Overall, the pooled HRs of SALP suggested that elevated level had an unfavorable impact on osteosarcoma patients' overall survival (OS) (HR = 1.82; 95% CI: 1.61–2.06; p < 0.001) and event-free survival (EFS) (HR = 1.97; 95% CI: 1.61–2.42; p < 0.001). Combined RRs of SALP indicated that elevated level was associated with presence of metastasis at diagnosis (RR = 5.55; 95% CI: 1.61–9.49; p = 0.006). No significantly different results were obtained after stratified by variables of age range, cancer stage, sample size, and geographic region. Conclusion. This meta-analysis demonstrated that high SALP level is significantly associated with poor OS or EFS rate and presence of metastasis at diagnosis. SALP level is a convenient and effective biomarker of prognosis for osteosarcoma.

Epithelioid Osteosarcoma of the Maxilla

Epithelioid osteosarcoma is an uncommon variant; only 4 cases have been reported in the jaw area, 2 of which were in the maxilla. A 22-year-old woman, in the eighth month of pregnancy, presented to the oral surgery clinic with a mass in the right maxilla that had rapidly expanded over the past 3 months. Computed tomography scans showed an ill-defined sclerotic destructive lesion that formed bone matrix in its soft tissue extension. Microscopic examination of the lesion revealed malignant epithelioid cells with osteoid deposits. The tumor cells were shown to have pale cytoplasm, vesicular nuclei, and prominent nucleoli and to undergo frequent mitosis. In addition, the tumor was positive for epithelial membrane antigen and vimentin and negative for AE1/AE3, Melan-A, CD30, synaptophysin, NSE, CD45, CD99, desmin, and myogenin. The final diagnosis was epithelioid osteosarcoma, which is a rare aggressive variant of osteosarcoma. Few cases of epithelioid osteosarcoma have been reported in the literature, and more studies are required to determine the clinical behavior of this tumor.

MicroRNA screening identifies circulating microRNAs as potential biomarkers for osteosarcoma

MicroRNAs (miRNAs) are a family of small non-protein coding RNAs, which regulate the expression of a wide variety of genes at the post-transcriptional level to control numerous biological and pathological processes. Various circulating miRNAs have been identified as potential diagnostic and prognostic biomarkers in multiple types of cancer and disease. The aim of the present study was to identify potential miRNA biomarkers for the early diagnosis and relapse prediction of osteosarcoma (OS). miRNA profiling was performed on serum from patients with osteosarcoma and healthy controls. All putative miRNAs were verified by reverse transcription-quantitative polymerase chain reaction analysis of 20 pre-therapeutic OS patients and 20 healthy individuals. The expression of miR-106a-5p, miR16-5p, miR-20a-5p, miR-425-5p, miR451a, miR-25-3p and miR139-5p was demonstrated to be downregulated in the serum of OS patients when compared with that of the healthy controls. Receiver-operating characteristic curve analyses indicated that these 7 miRNAs may be used as diagnostic biomarkers with the ability to discriminate between the healthy cohort and patients with OS. These results provide novel insights into the use of miRNAs in early blood screening for OS.

Cured of primary bone cancer, but at what cost: a qualitative study of functional impairment and lost opportunities

Purpose. Our study aims to explore how former cancer patients experience physical and psychosocial late effects 3–7 years after they underwent treatment for primary bone sarcoma in the hip/pelvic region. A qualitative, phenomenological, and hermeneutic design was applied. Methods. Sarcoma survivors (n = 10) previously treated at Oslo University Hospital, Norwegian Radium Hospital were selected to participate. In-depth and semistructured interviews were conducted. The interviews were analysed using inductive thematic analysis. Results. The participants reported that the late effects had three core spheres of impact: “their current daily life,” “their future opportunities,” and “their identity.” They expressed negative changes in activity, increased dependence on others, and exclusion from participation in different areas. Their daily life, work, sports activities, and social life were all affected. Several of their experiences are similar to those described by people with functional impairment or disability. Conclusion. Patients cured of bone cancer in the hip/pelvic region pay a significant price in terms of functional impairment, practical challenges, exclusion from important aspects of life, and loss of previous identity. It is important to appreciate this in order to help bone cancer survivors who struggle to reorient their life and build a secure new identity.

The association of MDM2 c.346G>A genetic variant with the risk of osteosarcoma in Chinese

Previous studies suggest that the MDM2 gene is one of the most important candidate genes for influencing the risk of osteosarcoma. This study aims to investigate the potential association of MDM2 c.346G>A genetic variant with the risk of osteosarcoma in Chinese. A total of 738 subjects were recruited in this study. The genotypes of MDM2 c.346G>A genetic variant were detected by the created restriction site-polymerase chain reaction. Our data suggest that the MDM2 c.346G>A genetic variant is associated with the increased risk of osteosarcoma in the homozygote comparison (AA vs. GG: odds ratio [OR]=2.36, 95% confidence interval [CI] 1.30-4.28, χ2=8.35, p=0.004), recessive model (AA vs.

GA/GG

OR=2.32, 95% CI 1.30-4.13, χ2=8.50, p=0.004), and allele comparison (A vs. G: OR=1.27, 95% CI 1.01-1.60, χ2=4.34, p=0.037). Results from this study indicated that the allele-A and genotype-AA of MDM2 c.346G>A genetic variant could be an increased risk factor for the susceptibility to osteosarcoma and might be used as a potential molecular marker for evaluating the risk of osteosarcoma.

PIK3CA and AKT gene polymorphisms in susceptibility to osteosarcoma in a Chinese population

PURPOSE

To explore the association between PIK3CA and AKT single nucleotide polymorphisms(SNP) and osteosarcoma susceptibility.

METHODS

TaqMan polymerase chain reaction(PCR) was used to detect the genotypes of SNPs (rs7646409, rs6973569 and rs9866361) in peripheral blood samples from 59 patients with osteosarcoma and from 63 healthy controls. Unconditional logistic regression was used to analyze the correlation between SNPs and osteosarcoma risk.

RESULTS

No statistically significant difference was found between osteosarcoma patients and healthy controls in the genotype of AKT rs6973569 (P = 0.7). However, after stratified analysis, the genotype AA of AKT rs6973569 carried a higher risk of osteosarcoma metastasis (OR:2.94, 95%CL:1.00-8.59); the difference of rs7646409 genotype distributions between the case and control groups was statistically significant (P = 0.032). Taking genotype TT as a reference, the risk of osteosarcoma increased three fold in patients with genotype CC (OR:3.47, 95%CL:1.26-9.56). A statistically significant difference was found between the alleles C and T (P=0.005). Further analysis showed that the risk factor was more pronounced in male patients with Enneking's stage IIB and osteoblastic osteosarcoma. PIK3CA rs9866361 did not fit Hardy-Weinberg equilibrium (P < 0.05).

CONCLUSIONS

Genotype CC in locus PIK3CA rs7646409 may increase the risk of osteosarcoma in the Chinese population.

Osteoclast inhibition impairs chondrosarcoma growth and bone destruction

Because Chondrosarcoma is resistant to available chemotherapy and radiation regimens, wide resection is the mainstay in treatment, which frequently results in high morbidity and which may not prevent local recurrence. There is a clear need for improved adjuvant treatment of this malignancy. We have observed the presence of osteoclasts in the microenvironment of chondrosarcoma in human pathological specimens. We utilized the Swarm rat chondrosarcoma (SRC) model to test the hypothesis that osteoclasts affect chondrosarcoma pathogenesis. We implanted SRC tumors in tibia of Sprague-Dawley rats and analyzed bone histologically and radiographically for bone destruction and tumor growth. At three weeks, tumors invaded local bone causing cortical disruption and trabecular resorption. Bone destruction was accompanied by increased osteoclast number and resorbed bone surface. Treatment of rats with the zoledronic acid prevented cortical destruction, inhibited trabecular resorption, and resulted in decreased tumor volume in bone. To confirm that inhibition of osteoclasts per se, and not off-target effects of drug, was responsible for the prevention of tumor growth and bone destruction, we implanted SRC into osteopetrotic rat tibia. SRC-induced bone destruction and tumor growth were impaired in osteopetrotic bone compared with control bone. The results from our animal model demonstrate that osteoclasts contribute to chondrosarcoma-mediated bone destruction and tumor growth and may represent a therapeutic target in particular chondrosarcoma patients.

Trophic activity of human P2X7 receptor isoforms A and B in osteosarcoma

The P2X7 receptor (P2X7R) is attracting increasing attention for its involvement in cancer. Several recent studies have shown a crucial role of P2X7R in tumour cell growth, angiogenesis and invasiveness. In this study, we investigated the role of the two known human P2X7R functional splice variants, the full length P2X7RA and the truncated P2X7RB, in osteosarcoma cell growth. Immunohistochemical analysis of a tissue array of human osteosarcomas showed that forty-four, of a total fifty-four tumours (81.4%), stained positive for both P2X7RA and B, thirty-one (57.4%) were positive using an anti-P2X7RA antibody, whereas fifteen of the total number (27.7%) expressed only P2X7RB. P2X7RB positive tumours showed increased cell density, at the expense of extracellular matrix. The human osteosarcoma cell line Te85, which lacks endogenous P2X7R expression, was stably transfected with either P2X7RA, P2X7RB, or both. Receptor expression was a powerful stimulus for cell growth, the most efficient growth-promoting isoform being P2X7RB alone. Growth stimulation was matched by increased Ca²⁺ mobilization and enhanced NFATc1 activity. Te85 P2X7RA+B cells presented pore formation as well as spontaneous extracellular ATP release. The ATP release was sustained in all clones by P2X7R agonist (BzATP) and reduced following P2X7R antagonist (A740003) application. BzATP also increased cell growth and activated NFATc1 levels. On the other hand cyclosporin A (CSA) affected both NFATc1 activation and cell growth, definitively linking P2X7R stimulation to NFATc1 and cell proliferation. All transfected clones also showed reduced RANK-L expression, and an overall decreased RANK-L/OPG ratio. Mineralization was increased in Te85 P2X7RA+B cells while it was significantly diminished in Te85 P2X7RB clones, in agreement with immunohistochemical results. In summary, our data show that the majority of human osteosarcomas express P2X7RA and B and suggest that expression of either isoform is differently coupled to cell growth or activity.

Association between CTLA-4 genetic polymorphisms and susceptibility to osteosarcoma in Chinese Han population

Osteosarcoma (OS) is the most common malignant primary bone tumor in the world. The cytotoxic T-lymphocyte antigen-4 gene (CTLA-4) is an important candidate gene for influencing the development of OS. This study aimed to investigate the potential association of CTLA-4 genetic polymorphisms with OS risk in Chinese Han population. A total of 415 OS patients and 431 healthy controls were enrolled in this study. The created restriction site-polymerase chain reaction (CRS-PCR) and DNA sequencing methods were used to detect the genotyping of CTLA-4 c.75G[C and c.326G[A genetic polymorphisms. We observed that the genotypes/alleles of c.75G[C and c.326G[A genetic polymorphisms were statistically associated with the increased risk of OS (for c.75G[C, CC versus (vs.) GG: OR 1.72, 95% CI 1.09–2.74; C vs. G: OR 1.30, 95% CI 1.06–1.60; for c.326G[A, AA vs. GG: OR 2.12, 95% CI 1.31–3.42; A vs. G: OR 1.31, 95% CI 1.07–1.61). The allele-C/genotype-CC of c.75G[C and allele-A/genotype-AA of c.326G[A may contribute to OS susceptibility. These data indicate that CTLA-4 genetic polymorphisms are potentially related to OS risk in Chinese Han population, and might be used as molecular markers for evaluating the risk of OS.