The incidence and prognosis of osteosarcoma skip metastases

Comparative Analysis of Skip Metastasis in Pediatric Osteosarcoma: Clinical Features and Outcomes

BACKGROUND

Skip metastasis (SM) is a synchronous regional bone metastasis. Using new imaging modalities, the detection of SM is easier and possibly more common. We reviewed patients with SM and compared their characteristics and outcomes to other patients with osteosarcoma treated at our center.

METHODS

We reviewed retrospectively children (<18 years) with newly diagnosed osteosarcoma who presented from June 2006 to March 2022. Patients' characteristics, treatment modalities, and outcomes were analyzed. All cases were discussed in a multidisciplinary clinic that included 2 experienced radiologists.

RESULTS

We identified 155 patients with osteosarcoma, among which 13 (8.3%) patients had SM detected by MRI. Patients with SM had a median age at diagnosis of 11.2 years (range 7 to 17). Three patients had lung metastasis at diagnosis. Bone scan was positive for the SM in 8 patients (62%). All patients underwent primary tumor resection after neoadjuvant chemotherapy (amputation in 5, limb salvage surgery in 8). Five had postchemotherapy necrosis ≥90% in primary tumor. Seven patients relapsed/progressed (1 local and 6 in the lung), all relapsed patients died of disease. Compared to the rest of the patients, those with SM had similar clinical features to patients without SM; outcomes were similar with no significant differences in event-free survival and overall survival ( P =0.7 and 0.3, respectively).

CONCLUSION

In this study, we observed a percentage of patients with SM comparable to previous reports. Patients with SM exhibited clinical features akin to the rest of our patients. Thorough evaluation of imaging studies and multidisciplinary care, coupled with meticulous surgical planning, are crucial for achieving a cure, which remained unjeopardized in our patients with SM.

The role of imaging in extremity sarcoma surgery

The surgical management of extremity bone and soft tissue sarcomas has evolved significantly over the last 50 years. The introduction and refinement of high-resolution cross-sectional imaging has allowed accurate assessment of anatomy and tumor extent, and in the current era more than 90% of patients can successfully undergo limb-salvage surgery. Advances in imaging have also revolutionized the clinician's ability to assess treatment response, detect metastatic disease, and perform intraoperative surgical navigation. This review summarizes the broad and essential role radiology plays in caring for sarcoma patients from diagnosis to post-treatment surveillance. Present evidence-based imaging paradigms are highlighted along with key future directions.

Microwave-induced hyperthermia in situ in the treatment of tumors of proximal humerus: long-term results with functionary sparing surgery

BACKGROUND

The present study aimed to evaluate the indications, feasibility, clinical effectiveness and complications of the treatment with microwave in situ inactivation followed by curettage and bone grafting assisted with internal fixation, for the proximal humerus tumors.

METHODS

The clinical data of 49 patients with primary or metastatic tumor of the proximal humerus who received intraoperative microwave inactivation in situ with curettage and bone grafting in our hospital from May 2008 to April 2021 were retrospectively analyzed.

RESULTS

There were 25 males and 24 females, with an average age of 57.6 ± 19.9 years (range, 20-81). All patients were followed up for 7 to 146 months, with an average period of 69.2 ± 39.8 months. Up to the last follow-up, 14 patients died. The 5-year overall survival was 67.3%, and 5-year tumor-specific survival was 71.4%. The 5-year tumor-specific survival rates were 100% for aggressive benign tumors or low potential malignancy tumors, 70.1% for primary malignancies, and 36.9% for metastatic tumors. The average preoperative MSTS, constant-Murley and VAS scores were 16.81 ± 3.85, 62.71 ± 12.56 and 6.75 ± 2.47, which were all significantly improved at 6 weeks after operation and at the final follow-up (P < 0.05).

CONCLUSIONS

Microwave inactivation in situ and curettage and bone grafting are a feasible treatment for tumors of proximal humeral, especially for malignant tumors and metastases, without the necessity of the replacement of the shoulder, with little trauma and good upper limb function, and with low local recurrence and distant metastasis.

PET/MR of pediatric bone tumors: what the radiologist needs to know

Integrated 2-deoxy-2-[fluorine-18]fluoro-D-glucose (18F-FDG) positron emission tomography (PET)/magnetic resonance (MR) imaging can provide "one stop" local tumor and whole-body staging in one session, thereby streamlining imaging evaluations and avoiding duplicate anesthesia in young children. 18F-FDG PET/MR scans have the benefit of lower radiation, superior soft tissue contrast, and increased patient convenience compared to 18F-FDG PET/computerized tomography scans. This article reviews the 18F-FDG PET/MR imaging technique, reporting requirements, and imaging characteristics of the most common pediatric bone tumors, including osteosarcoma, Ewing sarcoma, primary bone lymphoma, bone and bone marrow metastases, and Langerhans cell histiocytosis.

A cuproptosis-related genes signature associated with prognosis and immune cell infiltration in osteosarcoma

Osteosarcoma (OS) is one of the most prevalent primary bone tumors at all ages of human development. The objective of our study was to develop a model of Cuproptosis-Related Genes (CRGs) for predicting prognosis in OS patients. All datasets of OS patients were obtained from the Therapeutically Applicable Research to Generate Effective Treatments (TARGET) database and Gene Expression Omnibus (GEO) database. We obtained the gene set (81 CRGs) related to cuproptosis by accessing the database and previous literature. All the CRGs were analyzed by univariate COX regression, least absolute shrinkage and selection operator (LASSO) COX regression analysis to screen for CRGs associated with prognosis in OS patients. Then these CRGs were used to construct a prognostic signature, which was further verified by independent cohort (GSE21257) and clinical correlation analysis. Afterward, to identify underlying mechanisms, Gene Ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were used for the high-risk group by using the GSEA method. The association between the prognostic signature and 28 types of immune infiltrating cells in the tumor microenvironment was assessed. Ultimately, Lipoic Acid Synthetase (LIAS) (HR=0.632, P=0.004), Lipoyltransferase 1 (LIPT1) (HR=0.524, P=0.011), BCL2 Like 1 (BCL2L1/BCL-XL) (HR=0.593, P=0.022), and Pyruvate Dehydrogenase Kinase 1 (PDK1) (HR=0.662, P=0.025) were identified. Subsequently, they were used to calculate the risk score and build a prognostic model. In the training cohort, risk score (HR=1.878, P=0.003) could be considered as an independent prognostic factor, and OS patients with high-risk scores showed lower survival rates. Biological pathways related to substance metabolism and transport were enriched. There were significant differences in immune infiltrating cells in the tumor microenvironment. All in all, The CRGs signature is related to the tumor immune microenvironment and could be used as a credible predictor of the prognostic status in OS patients.

Osteosarcoma subtypes based on platelet-related genes and tumor microenvironment characteristics

Background

Osteosarcoma is a common metastatic tumor in children and adolescents. Because of its easy metastasis, patients often show a poor prognosis. Recently, researchers have found that platelets are closely related to metastasis of a variety of malignant tumors, but the role of platelets related characteristics in osteosarcoma is still unknown. The purpose of this study is to explore the characteristics of platelet-related subtypes and cell infiltration in tumor microenvironment.

Methods

We collected osteosarcoma cohorts from TCGA and GEO databases, and explored the molecular subtypes mediated by platelet-related genes and the related TME cell infiltration according to the expression of platelet-related genes in osteosarcoma. In addition, we also explored the differentially expressed genes (DEGs) among different molecular subtypes and established a protein-protein interaction network (PPI). Then we constructed a platelet scoring model by Univariate cox regression and least absolute shrinkage and selection operator (Lasso) cox regression model to quantify the characteristics of platelet in a single tumor. RT-PCR was used to investigate the expression of six candidate genes in osteosarcoma cell lines and normal osteoblast lines. Finally, we also predicted potential drugs with therapeutic effects on platelet-related subtypes.

Results

We found that platelet-related genes (PRGs) can distinguish osteosarcoma into two different platelet-related subtypes, C1 and C2. And the prognosis of the C2 subtype was significantly worse than that of C1 subtype. The results of ESTIMATE analysis and GO/KEGG enrichment showed that the differences between different subtypes were mainly concentrated in immune response pathways, and the immune response of C2 was inhibited relative to C1. We further studied the relationship between platelet-related subtypes and immune cell infiltration. We found that the distribution of most immune cells in C1 subtype was higher than that in C2 subtype, and there was a correlation between C1 subtype and more immune cells. Finally, we screened the PRGs related to the prognosis of osteosarcoma through Univariate Cox regression, established independent prognostic platelet characteristics consisting of six genes to predict the prognosis of patients with OS, and predicted the drugs that may be used in the treatment of osteosarcoma. RT-PCR was used to verify the expression of candidate genes in osteosarcoma cells.

Conclusion

Platelet scoring model is a significant biomarker, which is of great significance to determine the prognosis, molecular subtypes, characteristics of TME cell infiltration and therapy in patients with OS.

Management of Primary Aggressive Tumors of the Knee

Primary bone sarcomas and aggressive benign bone tumors are relatively rare. It is essential to recognize features that are concerning for these aggressive tumors based on a patient's history, physical exam, and radiographs. Physicians and other health care providers should have a high suspicion for these tumors and promptly refer these patients to orthopaedic oncologists. A multidisciplinary, team-based approach is required to obtain an accurate diagnosis and provide comprehensive care. This review discussed the appropriate work-up, biopsy principles, relevant peri-operative medical management, and surgical treatment options for patients with aggressive primary bone tumors around the knee. Primary bone sarcomas (osteosarcoma and chondrosarcoma) and aggressive benign bone tumors (giant cell tumor, chondroblastoma, and chondromyxoid fibroma) that have a predilection to the distal femur and proximal tibia are the focus of this review.

Pediatric Osteosarcoma: Pearls and Pitfalls

Osteosarcoma is a malignant bone tumor most commonly presenting in children. It has a bimodal distribution with a peak incidence occurring during the ages of 10-14 years old and in adults greater than age 65. The first peak of osteosarcoma correlates with the increased proliferation of bone during the pubertal growth period. Osteosarcoma most frequently presents with localized bone pain, swelling, and an antalgic gait. The patient may attribute symptoms to trauma or strenuous exercise, causing the patient to be managed conservatively. In these cases, the pain persists and eventually leads to further evaluation. The most common type of osteosarcoma is the conventional high-grade osteosarcoma. For conventional osteosarcoma, the diagnosis is typically made or strongly suggested based upon the initial radiographic appearance. Other types of osteosarcomas include low grade central, telangiectatic, small-cell, surface and intracortical. Consequently, it is important for radiologists to be aware of these subtypes and the imaging features that differentiate them from other etiologies to prevent a delay in treatment.

Skip metastases in high-grade intramedullary appendicular osteosarcoma: an indicator of more aggressive disease?

OBJECTIVE

To determine whether skip metastases (SM) in high-grade appendicular osteosarcoma (HG-OS) are an indicator of more aggressive disease.

MATERIALS AND METHOD

Retrospective review of patients with histologically confirmed diagnosis HG-OS of the long bones from 2007 to 2020, who had whole-bone MRI to identify SM. Data collected included patient age/gender, bone involved, the presence of SM, the presence of lung metastases from chest CT, the presence of distant bone metastases from whole-body bone scintigraphy or whole-body MRI, and chemotherapy response from resection specimen histology. The presence of lung or bone metastases and chemotherapy response were compared between patients without and with SM.

RESULTS

The study included 241 patients (146 males; 95 females: mean age 18.2 years; range 4-73 years). Based on whole-bone MRI, 202 (83.8%) patients had no SM and 39 (16.2%) patients had a SM. Of patients without a SM, lung metastases were identified in 44 (22%) and distant bone metastases in 6 (3%) cases, while 80 (43%) had a good chemotherapy response and 105 (57%) had a poor chemotherapy response. Of patients with a SM, lung metastases were identified in 22 (58%) and distant bone metastases in 8 (21%) cases, while 11 (32%) had a good chemotherapy response and 23 (68%) had a poor chemotherapy response. The presence of SM was significantly associated with both lung metastases (p < 0.001) and skeletal metastases (p < 0.001), but not with chemotherapy response (p = 0.24). Patients with SM also had poorer survival (p < 0.001).

CONCLUSIONS

The presence of SM in appendicular HG-OS suggests more aggressive disease.

Ferroptosis-related gene signature associates with immunity and predicts prognosis accurately in patients with osteosarcoma

Osteosarcoma has been the most common malignant bone tumor in children and adolescents, while the 5‐y survival of osteosarcoma patients gained no significant improvement over the past decades. This study aimed to explore the role of ferroptosis‐related genes (FRGs) in the development and prognosis of osteosarcoma. The datasets of osteosarcoma patients including RNA sequencing data and clinical information were acquired from the TRGET and Gene Expression Omnibus (GEO) databases. The identification of molecular subgroups with different FRG expression patterns was achieved through nonnegative matrix factorization (NMF) clustering. The prognostic model was constructed using the least absolute shrinkage and selection operator (LASSO) algorithm and multivariate Cox regression analysis. The ESTIMATE algorithm was applied for determining the stromal score, immune score, ESTIMA score, and tumor purity of osteosarcoma patients. Functional analyses including Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses, Gene Set Enrichment Analysis (GSEA), and Gene Set Variation Analysis (GSVA) were conducted to explore the underlying mechanisms in the development and prognosis of osteosarcoma. Two molecular subgroups with different FRGs expression patterns were identified. The molecular subgroups with higher immune score and more active immune status showed better prognostic survival. On the basis of FRGs, a prognostic model and a nomogram integrating clinical characteristics were constructed and their prediction efficiency for osteosarcoma prognosis were well validated. Gene functional enrichment analysis showed that these differentially expressed FRGs were mainly enriched in immunity‐related signaling pathways, indicating that FRGs may affect the development and prognosis of osteosarcoma by regulating the immune microenvironment. The expression profiles of FRGs were closely related to the immunity status and prognostic survival of osteosarcoma patients. The interaction between ferroptosis and immunity in the development of osteosarcoma could provide a new insight into the exploration of molecular mechanisms and targeted therapies of osteosarcoma patients.

Diagnosis and staging of malignant bone tumours in children: what is due and what is new?

PURPOSE

Although malignant bone tumours in children are infrequent, it is important to know how to properly diagnose and stage them, in order to establish an adequate treatment.

METHODS

We present a review of the diagnostic workflow of malignant bone tumours in children, including history and clinical examination, imaging, laboratory tests and biopsy techniques. Moreover, the two most commonly used staging systems are reviewed.

RESULTS

History, clinical examination and laboratory tests are nonspecific for diagnosing malignant bone tumours in children. Radiographs remain the mainstay for initial diagnosis, with MRI the modality of choice for local assessment and staging. Fluorine-18 labelled fluoro-deoxy-glucose-positron emission tomography scans provide a noninvasive method to assess the aggressiveness of the tumour and to rule out metastasis and is replacing the use of the bone scintigraphy. Biopsy must be always performed under the direction of the surgeon who is to perform the surgical treatment and after all diagnostic evaluation has been done. Staging systems are useful to study the extent of the tumour and its prognosis. They are expected to evolve as we better understand new molecular and genetic findings.

CONCLUSION

When a malignant bone tumour is suspected in a child, it is essential to make a correct diagnosis and referral to an experienced centre. Following an appropriate workflow for diagnosis and staging facilitates, prompt access to treatment improves outcomes.

LEVEL OF EVIDENCE

Level V Expert opinion.

Updating on Bone and Soft Tissue Sarcomas Staging

Bone and soft tissue sarcomas consist of a heterogeneous group of malignant tumors of mesenchymal origin that can affect patients from any age. The precise staging of these lesions determines the best therapeutic strategies and prognosis estimates. Two staging systems are the most frequently used: the system proposed by the University of Florida group, led by Dr. William F. Enneking (1980) and adopted by the Musculoskeletal Tumor Society (MSTS), and the system developed by the American Joint Committee on Cancer (AJCC) (1977), currently in its 8 th edition (2017). This paper updates the reader on the staging of bone and soft tissue sarcomas affecting the musculoskeletal system.

Imaging of Pediatric Bone Tumors and Tumor-like Lesions

Bone lesions are commonly seen when reporting pediatric skeletal imaging. Distinguishing aggressive from nonaggressive lesions is essential in making the diagnosis. Not all aggressive lesions are neoplastic; indeed, osteomyelitis frequently presents with aggressive appearances and is far more commonly seen in the pediatric population than neoplastic lesions. In this article, we discuss an approach for the diagnosis of pediatric bone tumors and tumor-like conditions. The most common pediatric benign and malignant bone tumors are discussed in more detail.

Osteosarcoma: a review of current and future therapeutic approaches

Osteosarcoma (OS) is the most common primary bone malignancy that affects children and young adults. OS is characterized by a high degree of malignancy, strong invasiveness, rapid disease progression, and extremely high mortality rate; it is considered as a serious threat to the human health globally. The incidence of OS is common in the metaphysis of long tubular bones, but rare in the spine, pelvis, and sacrum areas; moreover, majority of the OS patients present with only a single lesion. OS has a bimodal distribution pattern, that is, its incidence peaks in the second decade of life and in late adulthood. We examine historical and current literature to present a succinct review of OS. In this review, we have discussed the types, clinical diagnosis, and modern and future treatment methods of OS. The purpose of this article is to inspire new ideas to develop more effective therapeutic options.

Clinical Guideline for Microwave Ablation of Bone Tumors in Extremities

Microwave ablation has been used to treat bone tumors in extremities for more than 30 years. With improved recognition, updated microwave equipment, and expanded clinical application, microwave ablation has recently been widely used to treat bone tumors. To standardize the application of microwave ablation in the clinical treatment of bone tumors in the limbs, research results and clinical experience involving the use of microwave ablation to treat bone tumors in the limbs have been summarized, and a clinical guideline has been designed. This guideline is aimed at providing a reliable clinical basis for indications, preoperative evaluation and decision-making, perioperative treatment, complications, and other issues via evidence-based medicine. Two aspects are considered-percutaneous microwave ablation and intraoperative microwave ablation of bone tumors in extremities. Ultimately, the guideline is intended to standardize treatment and improve the clinical efficacy of microwave ablation of bone tumors in extremities.

The incidence of skip metastases on whole bone MRI in high-grade bone sarcomas

INTRODUCTION

Skip metastases have been described with osteosarcoma, Ewing sarcoma and rarely chondrosarcoma. The aim of this study was to determine the incidence of skip metastases on whole bone MRI in all primary high-grade sarcomas of the major long bones.

MATERIALS AND METHOD

Retrospective review of patients from April 2007 to April 2019 with high-grade primary bone sarcomas of the humerus, radius, ulna, femur, tibia or fibula who had whole bone MRI at initial staging. Data collected included age, sex, tumour type, presence and location of skip metastases based on whole bone MRI and presence of distant metastases (the skeleton and lung).

RESULTS

The study included 216 males and 171 females with mean age 30.6 years (range 4-92 years). Tumour types were as follows: High-grade osteosarcoma n = 202, Ewing sarcoma n = 68, high-grade chondrosarcoma n = 44, dedifferentiated chondrosarcoma n = 37, high-grade spindle cell sarcoma n = 29 and angiosarcoma n = 7. Skip lesions were identified in 63 (16.3%). However, after taking into account the presence of distant skeletal (n = 11) and pulmonary (n = 33) metastases, the overall incidence of skip metastases was 6.5%, occurring in 15 (7.5%) high-grade osteosarcomas, 3 (4.5%) Ewing sarcoma, 1 (2.8%) high-grade chondrosarcoma, 4 (10.8%) dedifferentiated chondrosarcomas, and 2 (6.9%) high-grade spindle cell sarcomas. A false positive MRI diagnosis of skip metastasis was made in 4 cases, 3 enchondromata and one focal nodular marrow hyperplasia.

CONCLUSION

The current study has documented the incidence of skip metastases in common types of high-grade primary bone sarcoma. The possibility of false positive skip metastases has also been highlighted.

The sensitivity, specificity, and diagnostic accuracy of whole-bone MRI for identifying skip metastases in appendicular osteosarcoma and Ewing sarcoma

OBJECTIVE

Pre-operative whole-bone MRI is required to assess intra-osseous tumour extent and to identify skip metastases in cases of bone sarcoma. The current study aims to determine the sensitivity, specificity, and diagnostic accuracy of whole-bone MRI for the identification of skip metastases.

MATERIALS AND METHOD

Review of 162 patients with long bone osteosarcoma or Ewing sarcoma who had undergone whole-bone MRI to assess intra-osseous tumour length and identify skip metastases. Comparison was made with post-chemotherapy MRI to look for a change in the appearance of suspected skip metastases, and resection specimens were assessed for the presence of skip metastases. The presence of local osseous recurrence was determined at final follow-up.

RESULTS

There were 112 males and 50 females (mean age 18.8 years), with 119 osteosarcomas and 43 Ewing sarcomas. Skip metastases were diagnosed on whole-bone MRI in 23 cases (14.2%). In 2 cases, pre-operative needle biopsy diagnosed enchondromata, resulting in false positive diagnoses. Skip metastases were diagnosed in the resection specimens in 3 cases, and based on comparison with post-chemotherapy MRI in 12. There was no evidence of local osseous recurrence in 160 patients, while late recurrence occurred in 2 patients. Sensitivity was calculated as 88.2%, specificity as 97.6%, and diagnostic accuracy as 96.7%.

CONCLUSION

Whole-bone MRI has a high sensitivity, specificity, and diagnostic accuracy for the identification of skip metastases in osteosarcoma and Ewing sarcoma. The possibility of false positive skip lesions and late local osseous recurrence is also highlighted.

Use Of Microwave Thermal Ablation In Management Of Skip Metastases In Extremity Osteosarcomas

Background

The objective of this study was to evaluate the efficiency and safety of microwave thermal ablation in the treatment of skip metastases in extremity osteosarcomas. Osteosarcoma of extremities with skip metastases has a poor prognosis, and thus, microwave thermal ablation presents an attractive minimally invasive option in this patient group.

Methods

A retrospective review included a cohort of 76 patients with extremity osteosarcoma in one institute, of which five cases (6.6%) showed skip metastases. Skip lesions located in proximal femur and primary sites were distal femur in all five patients. The authors treated skip lesions using microwave thermal ablation after primary tumors were removed at wide margins. Procedural efficacy and safety were determined with postoperative MSTS score and follow-ups of 12–62 months (median 22 months).

Results

The ablation time was five to nine minutes (mean seven minutes). Taking advantage of Microwave-induced hyperthermia, wide resections of distal femur and endoprosthesis reconstructions were performed instead of total femoral resection and replacement in four patients, and above-knee amputation was performed instead of hip disarticulation in one patient. The postoperative hip functions were intact and the mean lower extremity MSTS score was 26. Three patients died at 12–22 months after definitive surgery because of pulmonary metastases, and two patients remained disease-free at 44 and 62 months after surgery, respectively. No local recurrence either at sites of primary tumors or skip lesions was found at time of the latest follow up.

Conclusion

Microwave thermal ablation is efficacious in treating skip metastases of osteosarcoma in extremities. The modality has promise for good local control of tumors, less invasive surgeries, and intact and satisfied lower extremity functions in these relatively poor prognosis patients.

Level of evidence

Therapeutic Level III.

Survival of osteosarcoma patients following diagnosis of synchronous skip metastases

Background

We aim to investigate the prognostic implications of synchronous skip metastases in osteosarcoma by presenting the largest single centre series to date.

Methods

Retrospective study of 21 osteosarcoma patients with skip metastases treated between 1983 and 2004.

Results

No statistical difference in overall survival was demonstrated when comparing presence of lung metastases to those without (p = 0.859). No statistical difference was found in overall survival according to age group (<18yrs vs >18yrs; p = 0.126), or to percentage chemotherapy-induced bone necrosis (<90% vs >90%; p = 0.056).

Conclusions

The presence of skip metastases confers a very poor prognosis as an independent variable.

Level of evidence

III.

[The importance of radiology in bone sarcoma diagnostics : Initial and advanced diagnostics]

BACKGROUND

Reliable diagnostic assessment of malignant bone lesions remains a challenge in all the medical disciplines involved. The high incidence of benign (mainly pediatric) bone lesions needs to be distinguished from the rare malignant counterparts. If clinical presentation and patient history are unable to exclude a malignant tumour, adequate imaging of the affected region is necessary.

OBJECTIVES

This article focuses on giving implementable advice in dealing with problems and questions arising in the diagnostic process of treating patients with suspected or confirmed bone sarcoma. Also, follow-up recommendations from a radiological point of view are presented.

METHODS

Review and discussion of relevant literature against personal experiences in the medical imaging of patients with bone sarcomas.

RESULTS

Interpretation of projection radiographic images usually succeeds in assessing a bone tumour's dignity by evaluating periosteal reaction, the formation of a tumour matrix and consideration of the Lodwick classification. A current adaptation of the classic Lodwick classification incorporates diagnostic possibilities of more recent imaging techniques (magnetic resonance imaging (MRI), positron emission tomography (PET)) and is presented in this article. Plain radiographs are superseded by MRI as the primary imaging performed when depicting bone lesions with increasing frequency. The role of MRI in terms of primary diagnostics, staging, planning of biopsy tracts and tumour resections, evaluation of treatment response and follow-up are discussed. All diagnostic imaging techniques, including whole-body imaging methods, relevant in the diagnosis and therapy of bone sarcomas are presented in the sequence in which they appear during treatment.

CONCLUSIONS

Radiological imaging and expertise are important pillars in diagnosis and treatment of bone sarcomas. A variety of complementing imaging techniques provide a treatment-relevant basis significant for all medical disciplines involved.

An update on emerging drugs in osteosarcoma: towards tailored therapies?

Introduction: Current treatment of conventional and non-conventional high-grade osteosarcoma (HGOS) is based on the surgical removal of primary tumor and, when possible, of metastases and local reccurrence, together with systemic pre- and post-operative chemotherapy with drugs that have been used since decades. Areas covered: This review is intended to summarize the new agents and therapeutic strategies that are under clinical evaluation in HGOS, with the aim to increase the cure probability of this highly malignant bone tumor, which has not significantly improved during the last 30-40 years. The list of drugs, compounds and treatment modalities presented and discussed here has been generated by considering only those that are included in presently ongoing and recruiting clinical trials, or which have been completed in the last 2 years with reported results, on the basis of the information obtained from different and continuously updated databases. Expert opinion: Despite HGOS is a rare tumor, several clinical trials are presently evaluating different treatment strategies, which may hopefully positively impact on the outcome of patients who experience unfavorable prognosis when treated with conventional therapies.

The current status of MRI in the pre-operative assessment of intramedullary conventional appendicular osteosarcoma

Osteosarcoma is the commonest primary malignant bone tumour in children and adolescents, the majority of cases being conventional intra-medullary high-grade tumours affecting the appendicular skeleton. Treatment is typically with a combination of neo-adjuvant chemotherapy, tumour resection with limb reconstruction and post-operative chemotherapy. The current article reviews the role of magnetic resonance imaging (MRI) in the pre-operative assessment of high-grade central conventional osteosarcoma.

miR-503 is down-regulated in osteosarcoma and suppressed MG63 proliferation and invasion by targeting VEGFA/Rictor

We analyzed the expression of miR-503 in osteosarcoma tissues (OS) and discussed the clinical significance of our findings. To provide a theoretical basis for clinical applications, prognosis prediction and treatment of osteosarcoma, we studied the biological function of miR-503 and its mechanism in MG63 osteosarcoma cells. Real-time polymerase chain reaction (PCR) was used to detect the expression of miR-503 in 45 OS tissues and 20 osteochondroma tumors, analyzing the relationship between clinical pathology and follow-up data. Cox multivariate analysis revealed the clinical and pathological features of the osteosarcoma index and the influence of miR-503 expression on OS prognosis. To observe the effect on cell proliferation and invasion, MG-63 cells were transfected with miR-503. The TargetScan and PicTar bioinformatics method was used to analyze the probable target gene of miR-503 and, combined with the function of the target genes, resulted in a final validation of related pathways. miR-503 was significantly down-regulated in primary OS samples (26/45, 57.8%). The median miR-503 expression level in osteosarcoma was two-fold lower than that in osteochondroma (median expression 6.4 and 13.09, respectively, P< 0.05). The less-expressed miR-503 was associated with Enneking stage (p= 0.004) and invasion (p= 0.015) of OC. Patients with low miR-503 expression had poorer overall survival time. In the multivariate analysis, miR-503 was a significant prognostic factor (P= 0.010). miR-503 can inhibit proliferation and invasion in the MG63 cell line. Using bioinformatics, VEGFA and Rictor were determined to be the likely downstream target genes of miR-503. VEGFA, Rictor, Akt and Erk1/2 were negatively regulated by the overexpression of miR-503. In conclusion, miR-503 has significant tumor-suppressor biological activity and is thus likely to become a new target for the treatment of osteosarcoma.

Management of Bone Sarcoma

Treatment of bone sarcoma requires careful planning and involvement of an experienced multidisciplinary team. Significant advancements in systemic therapy, radiation, and surgery in recent years have contributed to improved functional and survival outcomes for patients with these difficult tumors, and emerging technologies hold promise for further advancement.

Osteosarcoma Overview

Osteosarcoma (OS) is the most common primary malignancy of bone and patients with metastatic disease or recurrences continue to have very poor outcomes. Unfortunately, little prognostic improvement has been generated from the last 20 years of research and a new perspective is warranted. OS is extremely heterogeneous in both its origins and manifestations. Although multiple associations have been made between the development of osteosarcoma and race, gender, age, various genomic alterations, and exposure situations among others, the etiology remains unclear and controversial. Noninvasive diagnostic methods include serum markers like alkaline phosphatase and a growing variety of imaging techniques including X-ray, computed tomography, magnetic resonance imaging, and positron emission as well as combinations thereof. Still, biopsy and microscopic examination are required to confirm the diagnosis and carry additional prognostic implications such as subtype classification and histological response to neoadjuvant chemotherapy. The current standard of care combines surgical and chemotherapeutic techniques, with a multitude of experimental biologics and small molecules currently in development and some in clinical trial phases. In this review, in addition to summarizing the current understanding of OS etiology, diagnostic methods, and the current standard of care, our group describes various experimental therapeutics and provides evidence to encourage a potential paradigm shift toward the introduction of immunomodulation, which may offer a more comprehensive approach to battling cancer pleomorphism.

Advances in emerging drugs for osteosarcoma

INTRODUCTION

Osteosarcoma (OS), the most common primary malignant bone tumor, is currently treated with pre- and postoperative chemotherapy in association with the surgical removal of the tumor. Conventional treatments allow to cure about 60 - 65% of patients with primary tumors and only 20 - 25% of patients with recurrent disease. New treatment approaches and drugs are therefore highly warranted to improve prognosis.

AREAS COVERED

This review focuses on the therapeutic approaches that are under development or clinical evaluation in OS. Information was obtained from different and continuously updated data bases, as well as from literature searches, in which particular relevance was given to reports and reviews on new targeted therapies under clinical investigation in high-grade OS.

EXPERT OPINION

OS is a heterogeneous tumor, with a great variability in treatment response between patients. It is therefore unlikely that a single therapeutic tool will be uniformly successful for all OS patients. This claims for the validation of new treatment approaches together with biologic/(pharmaco)genetic markers, which may select the most appropriate subgroup of patients for each treatment approach. Since some promising novel agents and treatment strategies are currently tested in Phase I/II/III clinical trials, we may hope that new therapies with superior efficacy and safety profiles will be identified in the next few years.

The role of magnetic resonance imaging in the evaluation of bone tumours and tumour-like lesions

Bone tumours and tumour-like lesions are frequently encountered by radiologists. Although radiographs are the primary screening technique, magnetic resonance imaging (MRI) can help narrow the differential or make a specific diagnosis when a lesion is indeterminate or shows signs of aggressiveness. MRI can extend the diagnostic evaluation by demonstrating several tissue components. Even when a specific diagnosis cannot be made, the differential diagnosis can be narrowed. MRI is superior to the other imaging modalities in detecting bone marrow lesions and tumoral tissue (faint lytic/sclerotic bone lesions can be difficult to visualise using only radiographs). Contrast-enhanced MRI can reveal the most vascularised parts of the tumour and MRI guidance makes it possible to avoid biopsing necrotic areas. MRI is very helpful in local staging and surgical planning by assessing the degree of intramedullary extension and invasion of the adjacent physeal plates, joints, muscle compartments and neurovascular bundles. It can be used in assessing response to neoadjuvant therapy and further restaging. The post-therapeutic follow-up should also be done using MRI. Despite the high quality of MRI, there are a few pitfalls and limitations of which one should be aware. Applications of MRI in bone tumours will probably continue to grow as new sequences are further studied.

TEACHING POINTS

• When a lesion is indeterminate or shows signs of aggressiveness, MRI is indicated. • When MRI does not lead to a diagnosis, biopsy is indicated. • MRI is superior to the other imaging modalities in detecting bone marrow lesions. • MRI is very helpful in local staging and surgical planning. • MRI is used in assessing the response to neoadjuvant therapy, restaging and post-therapeutic follow-up.

Osteosarcoma

Osteosarcoma is a malignant tumor that primarily affects the long bones but can also involve other bones in the body.  It has a bimodal distribution with peaks in the second decade of life and late adulthood.  This chapter will highlight the clinical presentation, diagnosis, and treatment of osteosarcoma.

Atypical Presentation of High-Grade Intramedullary Osteosarcoma with Bilateral Cervical, Supraclavicular, and Axillary Lymphadenopathy: A Case Report and Literature Review

Osteosarcoma typically presents with primary site pain. The authors report a case of extensive metastatic osteosarcoma without any complaint of primary site pain during initial presentation. The 23-year-old female patient presented with simultaneous multiple cervical, supraclavicular, and axillary lymphadenopathy, as well as two large subcutaneous fat tumours. Despite initial excision biopsy of cervical lymph nodes, the diagnosis of osteosarcoma was only clinched after open biopsy of the right distal femur lesions and further histological evaluation. Though the patient was promptly started on neo-adjuvant chemotherapy and achieved excellent histological response to treatment, the disease had relapsed quickly and she succumbed to the disease one year after initial presentation. This report highlights the need to be vigilant in the workup and investigation of osteosarcoma, as the presenting symptoms may be more heterogenous than the conventional teaching of primary site pain.

Osteosarcoma treatment - where do we stand? A state of the art review

Long-term outcome for patients with high-grade osteosarcoma has improved with the addition of systemic chemotherapy, but subsequent progress has been less marked. Modern, multiagent, dose-intensive chemotherapy in conjunction with surgery achieves a 5-year event-free survival of 60-70% in extremity localized, non-metastatic disease. A major, as yet unsolved, problem is the poor prognosis for metastatic relapse or recurrence, and for patients with axial disease. This article reviews the current state of the art of systemic osteosarcoma therapy by focusing on the experiences of cooperative osteosarcoma groups. Also, we shed light on questions and challenges posed by the aggressiveness of the tumor, and we consider potential future directions that may be critical to progress in the prognosis of high-grade osteosarcoma.

Osteosarcoma of jaws

Tumors of jaw bones are among the most uncommon of all types of neoplasms. Osteosarcoma of jaw bones represents a distinct group of lesions from the conventional type commonly occurring in long bones. Nonetheless, our present knowledge of the tumor allows us to affirm that its clinical behavior and pathologic features differ markedly from those of its homolog in the long bones. The maxillary tumors show predilection for posterior portion of the alveolar process and the antrum, whereas the body is most commonly involved in the mandible followed, by angle, symphysis, and ascending ramus. We have reviewed around 300 cases of osteosarcoma of varied racial origin from PubMed indexed journals spanning from 1967 to 2010 and present their etiology, pathogenesis, features and treatment modalities.

Imaging pediatric bone sarcomas

Primary malignant bone tumors are rare and account for about 6% of all new pediatric cancer cases per year in the United States. Identification of the lesion not uncommonly occurs as a result of imaging performed for trauma. Clinical and standard imaging characteristics of the various tumor types are evolving in concert with treatment advancements and clinical trial regimens. This article reviews the 3 most common pediatric bone sarcomas-osteosarcoma, Ewing sarcoma, and chondrosarcoma-and their imaging as applicable to contemporary disease staging and monitoring, and explores the roles of evolving imaging techniques.

The prognosis for patients with osteosarcoma who have received prior manipulative therapy

We evaluated the long-term outcome of patients with an osteosarcoma who had undergone prior manipulative therapy, a popular treatment in Asia, and investigated its effects on several prognostic factors. Of the 134 patients in this study, 70 (52%) patients had manipulative therapy and 64 (48%) did not. The age, location, and size of tumour were not significantly different between the groups. The five-year overall survival rate was 58% and 92% in the groups with and without manipulative therapy (p = 0.004). Both the primary and overall rates of lung metastasis were significantly higher in the manipulative group (primary: 32% vs 3%, p = 0.003; overall lung metastasis rate: 51.4% vs 18.8%, p < 0.001). Patients who had manipulative therapy had higher local recurrence rates in comparison to patients who did not (29% vs 6%, p = 0.011). The prognosis for patients with osteosarcoma who had manipulative therapy was significantly poorer than those who had not. Manipulative therapy was an independent factor for survival. This form of therapy may serve as a mechanism to accelerate the spread of tumour cells, and therefore must be avoided in order to improve the outcome for patients with an osteosarcoma.

Local recurrence, survival and function after total femur resection and megaprosthetic reconstruction for bone sarcomas

BACKGROUND

The choices of treatment for patients with extensive tumors of the femur include total femur megaprosthesis or large allograft-prosthetic composites. Previous reports suggest variable survival ranging from 60-70% at 1 to 2 years. However, these studies described earlier prostheses and techniques.

QUESTIONS/PURPOSES

To confirm previous reports we determined (1) risk of local recurrence; (2) overall survivorship; and (3) function in patients with total femur reconstructions for tumors.

METHODS

We retrospectively reviewed 23 patients with total femur megaprostheses implanted between 1987 and 2006 after resection of bone tumors. Two patients lost at followup were excluded; the remaining 21 included 15 males and six females with a mean age of 21 years. The mean followup was 48 months (range, 1 month 17 years). Function was assessed according to the MSTS System II.

RESULTS

No patient developed a local recurrence during followup. At last followup, six patients were continuously disease-free at a mean of 148 months, one patient had no evidence of disease after treatment of a recurrence, one patient was alive with disease, and 13 patients died of their disease at a mean time of 17 months. In 15 patients evaluated with the MSTS score, the mean score was 66%; four patients had over 75%, eight from 51% to 75%, three from 26% to 50%. Four patients (19%) had complications requiring further surgery in absence of trauma. A fifth patient had a posttraumatic periprosthetic fracture.

CONCLUSIONS

A total femur prosthesis allows a limb-preserving procedure in tumors with extensive femoral involvement or in the presence of a skip lesion along the femur. The prognosis of these tumors is poor, but this reconstruction provides function with a relatively low rate of major complications.

Prognostic markers in osteosarcoma

Osteosarcoma is the most common bone tumor seen in the pediatric and adolescent age group. Survival rates in osteosarcoma have improved considerably from 20 to 65% since the 1980s with the advent of multiagent chemotherapy. Further improvement in survival has not been achieved owing to lack of well-validated prognostic markers and better therapeutic agents. Markers involved with angiogenesis, cell adhesion, apoptosis and cell cycle have been shown recently to play an important role in osteosarcoma growth, differentiation and metastasis. Over the coming years, the new molecular markers may be able not only to prognosticate osteosarcoma patients at baseline but also to serve as therapeutic targets and thereby improve survival rates further. Noninvasive imaging methods in osteosarcoma such as PET-CT and dynamic contrast enhanced and diffusion-weighted MRI hold a lot of promise as surrogate methods for prognostication and response assessment.

Establishment and characteristics of two syngeneic human osteosarcoma cell lines from primary tumor and skip metastases

AIM

To characterize and compare the different biological behaviors of 2 novel human osteosarcoma cell lines, Zos and Zos-M, established respectively from the primary tumor and the skip metastasis of an osteosarcoma patient.

METHODS

In vitro studies included morphological observations, karyotype analysis, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide cell proliferation assay, and cell sensitivity to chemotherapeutic drugs. Subcutaneous and intravenous inoculations into nude mice were carried out to study the tumorigenicity and the metastatic potential. RT-PCR was performed to assess the expression of the osteoblastic markers and some metastasis-related genes.

RESULTS

Both cell lines remained stable for more than 100 passages in vitro without interruption. The RT-PCR examination indicated that they retained the molecular characteristics of an osteoblastic lineage. The karyotype analysis displayed aneuploidy and various structural abnormalities. Both cell lines are tumorigenic; Zos-M differs from Zos by the former's ability to develop lung metastasis after intravenous injection. The comparison of the expression patterns of some metastasis-related genes revealed that the decreased expression of cadherin-11 in Zos-M may correlate with a high potential of metastases. Moreover, both cell lines are less sensitive to the current chemotherapy protocols.

CONCLUSION

The establishment of osteosarcoma cell lines, Zos and Zos-M, and related animal models provide a useful resource for studying the aggressive behavior of osteosarcoma and will be helpful for screening effective treatment strategies.

A review of clinical and molecular prognostic factors in osteosarcoma

Traditional prognostic determinants in osteosarcoma have included demographics (age, sex), tumour size, site, stage, and the response to chemotherapy. Many of these are determined using varying techniques and units of measurement, which can make comparison between studies difficult. The absence of survival difference between limb sparing surgery and amputation has been repeatedly demonstrated in primary disease, and even in the setting of pathological fracture. On the other hand, there is still some controversy over the existence of increased local recurrence for limb-sparing surgery, and the implications of this. Commonly used prognostic determinants such as metastases, and response to chemotherapy enable a high degree of prognostic accuracy but usually at a late stage in the course of disease. Leading on from this, there is a need to uncover molecular pathways with specific influence over osteosarcoma progression to facilitate earlier treatment changes. Some important pathways are already being defined, for example the association of CXCR4 with metastases on presentation, the likelihood of doxorubicin resistance with positive P-glycoprotein, and the reduced survival prediction of over expressed survivin. It is anticipated that the future of osteosarcoma treatment will involve treatment tailored to the molecular profile of tumours at diagnosis, adjuvant therapy directed towards dysfunctional molecular pathways rather than the use of cytotoxics, and a more standardised approach to the measurement of clinical prognostic factors.

Clinical outcome of osteosarcoma with primary total femoral resection

Primary total femoral resection and reconstruction rarely are indicated for patients with osteosarcoma. We determined the survivorship, complications, and functional outcome of patients with osteosarcomas who had total femoral resections. We evaluated 13 patients with osteosarcomas whose surgical conditions included multiple skip lesions along the femur (Group I, two patients), extensive femoral involvement without interruption (Group II, eight patients), and iatrogenic contamination of the femur secondary to an internal fixation (Group III, three patients). We analyzed the event-free survival, complications, and functional outcome and looked for obvious differences among the three groups. The minimum followup was 9 months (mean, 41 months; range, 9-125 months). The Kaplan-Meier event-free survival rate at 10 years was 34.6% (95% confidence interval, 7.5%-61.7%). All five patients in Groups I and III died. Four of eight patients in Group II were event-free survivors. Four patients had major complications. Five patients had good functional scores. The subset of patients who had relatively small tumors with wide resection margins had a good prognosis. In patients with other clinical conditions, hip disarticulation can be considered.

Primary bone osteosarcoma in the pediatric age: State of the art

The current combination treatment, chemotherapy and surgery, has significantly improved the cure rate and the survival rate of primary bone osteosarcoma. The 5-year survival rate has increased in the last 30 years from 10% to 70%. Even in patients with poor prognosis, such as those with metastases at diagnosis, the 5-year survival rate has reached 20-30% due to chemotherapy and the surgical removal of metastases and primary tumor. However, the most effective drugs are still the same as those employed over the last 20 years as front line neoadjuvant or adjuvant chemotherapy: Doxorubicin, Cisplatin, Methotrexate, Ifosfamide. No standard, second line therapy exists for those who relapse. At relapse, due to the lack of new non-cross-resistant drugs, surgery is still the main option when feasible. Other drugs have been employed in relapsed patients with poor results. This article reviews the state of the art of treatment for bone osteosarcoma in the pediatric age.

Skip metastases in osteosarcoma: experience of the Cooperative Osteosarcoma Study Group

PURPOSE

The outlook for patients with osteosarcoma who present with synchronous regional bone metastases (skip metastases), either in the primary bone site or transarticular, is considered to be extremely poor. This study was conducted to further investigate the prognostic implication of skip metastases in osteosarcoma.

PATIENTS AND METHODS

The authors retrospectively analyzed the collected data of 1,765 consecutive patients with newly diagnosed high-grade osteosarcoma of bone who were registered in the neoadjuvant Cooperative Osteosarcoma Study Group studies and identified 24 patients (1.4%) with unequivocally proven skip metastases. All 24 patients were treated by an aggressive surgical approach coupled with polychemotherapy. Demographic, diagnostic, tumor, and treatment-related variables and response and survival data were analyzed.

RESULTS

Skip metastases were identified preoperatively in 11 of 24 patients by bone scan, eight of 22 patients by plain x-ray, 15 of 18 patients by magnetic resonance imaging, and five of 10 patients by computed tomography. A complete surgical remission (CSR) of all clinically detectable tumor sites was achieved in 22 of 24 patients during front-line therapy. With a median follow-up time of 4.4 years (8 years for survivors) from diagnosis, 12 patients were alive, all of whom were in continuous CSR. Survival did correlate with location of skip metastases and histologic response to neoadjuvant chemotherapy.

CONCLUSION

Synchronous regional bone metastases are rare in osteosarcoma, and preoperative detection relies on appropriate diagnostic imaging. Aggressive multimodal therapy holds the promise to achieve prolonged survival, especially in patients in whom these metastases occur within the same bone as the primary lesion and whose tumors respond well to chemotherapy.