Team Approach: Osteosarcoma of the Distal Part of the Femur in Adolescents

Megaprosthesis Total Knee Replacement Following Resection of Extensive Osteoblastic Osteosarcoma in the Distal Femur: A Case Report

Osteosarcoma is the most common type of primary bone cancer, which usually appears in the distal femur. The diagnosis of this condition typically involves advanced imaging and tissue biopsy, as well as taking into account characteristic clinical and radiographic indicators. The treatment approach for distal femoral osteosarcoma is multidisciplinary and involves initial chemotherapy, followed by limb-sparing surgery, reconstruction of bone and soft tissue, and subsequent adjuvant chemotherapy. We present a case study of a 25-year-old male admitted with a blastic lesion in the distal femur, confirmed via open biopsy to be osteoblastic osteosarcoma. Further evaluation revealed multiple pulmonary nodular lesions, managed with chemotherapy. After four months, regression of the lesion was observed. Due to malignant clinical and imaging features, excision of the lesion and subsequent reconstruction were performed, utilizing a custom-made total knee arthroplasty. The excision encompassed the removal of the distal 14 cm of the femur, with histological examination confirming central osteoblastic osteosarcoma. Satisfactory outcomes were observed during a one-year follow-up, indicating promising results. Vigilance is crucial, especially in young patients with surface-type bone tumors, as this neoplasm requires consideration.

Strontium-loaded 3D intramedullary nail titanium implant for critical-sized femoral defect in rabbits

The treatment of critical-sized bone defects has long been a major problem for surgeons. In this study, an intramedullary nail shaped three-dimensional (3D)-printed porous titanium implant that is capable of releasing strontium ions was developed through a simple and cost-effective surface modification technique. The feasibility of this implant as a stand-alone solution was evaluated using a rabbit's segmental diaphyseal as a defect model. The strontium-loaded implant exhibited a favorable environment for cell adhesion, and mechanical properties that were commensurate with those of a rabbit's cortical bone. Radiographic, biomechanical, and histological analyses revealed a significantly higher amount of bone ingrowth and superior bone-bonding strength in the strontium-loaded implant when compared to an untreated porous titanium implant. Furthermore, one-year histological observations revealed that the strontium-loaded implant preserved the native-like diaphyseal bone structure without failure. These findings suggest that strontium-releasing 3D-printed titanium implants have the clinical potential to induce the early and efficient repair of critical-sized, load-bearing bone defects.

Assessment of the Interval to Diagnosis in Pediatric Bone Sarcoma

OBJECTIVES

The timely diagnosis of primary bone malignancies in pediatric patients is critical to clinical outcomes. The purpose of this study is to investigate the initial presentation of pediatric bone sarcoma patients to an academic health care system and assess the current interval to diagnosis.

METHODS

We conducted a retrospective review of pediatric patients (aged 1-18) with biopsy-proven diagnosis of osteosarcoma or Ewing sarcoma presenting between 2004 and 2020. All living patients had 1 year or more of follow-up. Primary outcomes were interval to diagnosis, clinical features on initial presentation, percent of patients with negative radiographic workup at initial presentation, and number of health care encounters before diagnosis.

RESULTS

Seventy-one patients (osteosarcoma, 51; Ewing sarcoma, 20) were included. Average age at presentation was 13.1 ± 3.3 years (range, 4.4-18.3). Average symptom duration was 5.4 ± 13.9 months (range, 0.1-84). Clinical features at initial presentation included limb/back pain (91.5% of patients), activity modification/pain medication use (78.9%), palpable mass (40.8%), night pain (35.2%), limp (25.4%), limb disuse (18.3%), and recent fever history (2.8%). Fourteen of 71 patients (19.7%) had negative radiographs at initial presentation. Average number of health care encounters before diagnosis was 1.9 ± 0.6 (range, 1.0-4.0), with most in the outpatient pediatrician clinics (81.2%) and emergency department (18.3%). Average time to diagnosis from initial presentation was 19.5 ± 65 days (range, 0-493); the 14 patients with initial negative radiographs had a statistically significant prolonged interval to diagnosis of 54 ± 134 days (range, 0-493; P = 0.018).

CONCLUSIONS

We found pediatric patients with primary bone sarcoma present with an average interval to diagnosis of 20 days. Twenty percent of patients had a significantly prolonged interval to diagnosis of 54 days. Clinical features suggest night pain is not a sensitive indicator. In patients of appropriate age with persistent unilateral pain in suspicious locations, early advanced imaging with magnetic resonance imaging should be considered.

A Feedback Loop of LINC00665 and the Wnt Signaling Pathway Expedites Osteosarcoma Cell Proliferation, Invasion, and Epithelial-Mesenchymal Transition

OBJECTIVES

Osteosarcoma (OS) is a malignant tumor with frequent occurrence among teenagers. Long non-coding RNAs (lncRNAs) play pro-cancer roles in many tumors. The purpose of this study was to figure out the functional role of a novel lncRNA long intergenic non-protein coding RNA 665 (LINC00665) in OS by observing the OS cell behaviors.

METHODS

Quantitative reverse transcription polymerase chain reaction (RT-qPCR) was used to analyze LINC00665 expression in OS cells. Cell function assays assessed the impacts of LINC00665 on OS cell phenotype. Immunofluorescence and western blot analyzed the function of LINC00665 on epithelial-mesenchymal transition (EMT) in OS. Moreover, mechanistic assays analyzed the downstream mechanism of LINC00665 in OS cells.

RESULTS

LINC00665 was significantly up-regulated in OS cells. LINC00665 silence facilitated OS cell proliferation, migration, invasion, and EMT while inhibiting cell apoptosis. Mechanically, LINC00665 acted as a competing endogenous RNA (ceRNA) to sponge miR-1249-5p and thereby modulated Wnt family member 2B (WNT2B) to activate Wnt pathway. Wnt pathway activated LINC00665 expression transcriptionally.

CONCLUSIONS

Our study uncovered the cancer-promoting role of LINC00665 in OS, and the feedback loop of LINC00665/miR-1249-5p/WNT2B/Wnt might be a potential target for OS treatment.

Pediatric Osteosarcoma: Correlation of Imaging Findings with Histopathologic Features, Treatment, and Outcome

Osteosarcoma is the most common primary bone sarcoma in children. Imaging plays a pivotal role in diagnostic workup, surgical planning, and follow-up monitoring for possible disease relapse. Survival depends on multiple factors, including presence or absence of metastatic disease, chemotherapy response, and surgical margins. At diagnosis, radiography and anatomic MRI are used to characterize the primary site of disease, whereas chest CT and whole-body bone scintigraphy and/or PET are used to identify additional sites of disease. Treatment starts with neoadjuvant chemotherapy, followed by en bloc tumor resection and limb reconstruction, and finally, adjuvant chemotherapy. Preoperative planning requires precise tumor delineation, which traditionally has been based on high-spatial-resolution anatomic MRI to identify tumor margins (medullary and extraosseous), skip lesions, neurovascular involvement, and joint invasion. These findings direct the surgical approach and affect the options for reconstruction. For skeletally immature children, the risk of cumulative limb-length discrepancy and need for superior longevity of the reconstruction have led to the advent and preferential use of several pediatric-specific surgical techniques, including rotationplasty, joint preservation surgery, autograft or allograft reconstruction, and extendible endoprostheses. A better understanding of the clinically impactful imaging features can directly and positively influence patient care. Online supplemental material is available for this article. ^©RSNA, 2022.

Correlation of histopathology and multi-modal magnetic resonance imaging in childhood osteosarcoma: Predicting tumor response to chemotherapy

Background

Osteosarcoma, which is the most common malignant pediatric bone cancer, remains dependent on an imprecise systemic treatment largely unchanged in 30 years. In this study, we correlated histopathology with magnetic resonance imaging (MRI), used the correlation to extract MRI-specific features representative of tumor necrosis, and subsequently developed a novel classification model for predicting tumor response to neoadjuvant chemotherapy in pediatric patients with osteosarcoma using multi-modal MRI. The model could ultimately serve as a testable biomarker for a high-risk malignancy without successful precision treatments.

Methods

Patients with newly diagnosed high-grade appendicular osteosarcoma were enrolled in a single-center observational study, wherein patients underwent pre-surgical evaluation using both conventional MRI (post-contrast T1-weighted with fat saturation, pre-contrast T1-weighted, and short inversion-time inversion recovery (STIR)) and advanced MRI (diffusion weighted (DW) and dynamic contrast enhanced (DCE)). A classification model was established based on a direct correlation between histopathology and MRI, which was achieved through histologic-MR image co-registration and subsequent extraction of MR image features for identifying histologic tumor necrosis. By operating on the MR image features, tumor necrosis was estimated from different combinations of MR images using a multi-feature fuzzy clustering technique together with a weighted majority ruling. Tumor necrosis calculated from MR images, for either an MRI plane of interest or whole tumor volume, was compared to pathologist-estimated necrosis and necrosis quantified from digitized histologic section images using a previously described deep learning classification method.

Results

15 patients were enrolled, of whom two withdrew, one became ineligible, and two were subjected to inadequate pre-surgical imaging. MRI sequences of n = 10 patients were subsequently used for classification model development. Different MR image features, depending on the modality of MRI, were shown to be significant in distinguishing necrosis from viable tumor. The scales at which MR image features optimally signified tumor necrosis were different as well depending on the MR image type. Conventional MRI was shown capable of differentiating necrosis from viable tumor with an accuracy averaging above 90%. Conventional MRI was equally effective as DWI in distinguishing necrotic from viable tumor regions. The accuracy of tumor necrosis prediction by conventional MRI improved to above 95% when DCE-MRI was added into consideration. Volume-based tumor necrosis estimations tended to be lower than those evaluated on an MRI plane of interest.

Conclusions

The study has shown a proof-of-principle model for interpreting chemotherapeutic response using multi-modal MRI for patients with high-grade osteosarcoma. The model will continue to be evaluated as MR image features indicative of tumor response are now computable for the disease prior to surgery.

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.

Characteristics, Management, and Outcomes of Patients With Osteosarcoma: An Analysis of Outcomes From the National Cancer Database

Introduction:

Previous studies about osteosarcoma patient characteristics, management, and outcomes have limited patient numbers, combine varied tumor types, and/or are older studies.

Methods:

Patients with osteosarcoma from the 2004 to 2015 National Cancer Database data sets were separated into axial, appendicular, and other. Demographic and treatment data as well as 1-, 5-, and 10-year survival were determined for each group. A multivariate Cox analysis of patient variables with the likelihood of death was performed, and the Kaplan Meier survival curves were generated.

Results:

Four thousand four hundred thirty patients with osteosarcoma (3,435 appendicular, 810 axial, and 185 other) showed survival at 1-year, 5-year, and 10-year and was highest among the appendicular cohort (91.17%, 64.43%, and 58.58%, respectively). No change in survival was seen over the periods studied. The likelihood of death was greater with increasing age category, distant metastases, and treatment with radiation alone but less with appendicular primary site, treatment with surgery alone, or surgery plus chemotherapy.

Discussion:

Despite advances in tumor management, surgical excision remains the best predictor of survival for osteosarcomas. No difference was observed in patient survival from 2004 to 2015 and, as would be expected, distant metastases were a poor prognostic sign, as was increasing age, male sex, and axial location.

Deep Learning Assisted Diagnosis of Musculoskeletal Tumors Based on Contrast-Enhanced Magnetic Resonance Imaging

BACKGROUND

Misdiagnosis of malignant musculoskeletal tumors may lead to the delay of intervention, resulting in amputation or death.

PURPOSE

To improve the diagnostic efficacy of musculoskeletal tumors by developing deep learning (DL) models based on contrast-enhanced magnetic resonance imaging and to quantify the improvement in diagnostic performance obtained by using these models.

STUDY TYPE

Retrospective.

POPULATION

Three hundreds and four musculoskeletal tumors, including 212 malignant and 92 benign lesions, were randomized into the training (n = 180), validation (n = 62) and testing cohort (n = 62).

FIELD STRENGTH/SEQUENCE

A 3 T/T₁ -weighted (T₁ -w), T₂ -weighted (T₂ -w), diffusion-weighted imaging (DWI), and contrast-enhanced T1-weighted (CET₁ -w) images.

ASSESSMENT

Three DL models based, respectively, on the sagittal, coronal, and axial MR images were constructed to predict the malignancy of tumors. Blinded to the prediction results, a group of specialists made independent initial diagnoses for each patient by reading all image sequences. One month after the initial diagnoses, the same group of doctors made another round of diagnoses knowing the malignancy of each tumor predicted by the three models. The reference standard was the pathological diagnosis of malignancy.

STATISTICAL TESTS

Sensitivity, specificity, and accuracy (all with 95% confidential intervals [CI]) corresponding to each diagnostic test were computed. Chi-square tests were used to assess the differences in those parameters with and without DL models. A P value < 0.05 was considered statistically significant.

RESULTS

The developed models significantly improved the diagnostic sensitivities of two oncologists by 0.15 (95% CI: 0.06-0.24) and 0.36 (95% CI: 0.24-0.28), one radiologist by 0.12 (95% CI: 0.04-0.20), and three of the four orthopedists, respectively, by 0.12 (95% CI: 0.04-0.20), 0.29 (95% CI: 0.18-0.40), and 0.23 (95% CI: 0.13-0.33), without impairing any of their diagnostic specificities (all P > 0.128).

DATA CONCLUSION

The DL models developed can significantly improve the performance of doctors with different training and experience in diagnosing musculoskeletal tumors.

EVIDENCE LEVEL

3 TECHNICAL EFFICACY: Stage 2.

WIPI1 promotes osteosarcoma cell proliferation by inhibiting CDKN1A

Detection of TCGA data revealed that WIPI1 is highly expressed in osteosarcoma cells. So we explore the mechanisms of WIPI1 affecting the proliferation of osteosarcoma cells through Affymetrix microarray analysis. Functional analysis of differentially expressed genes shows that the classical signaling pathways affecting tumor formation and development have changed significantly. By fitting analysis, it is speculated that the WIPI1 may function in the direction of osteosarcoma by regulating the expression of multiple cell cycle-related genes such as CDKN1A, CDK4 and CCND1. Therefore, the key genes are selected for RT-PCR and Western-blot verification. Combined with flow and other means, WIPI1 may affect the cell cycle and the osteosarcoma by regulating the expression of CDKN1A, CDK4 and CCND1. To verify the results, the effect of WIPI1 on cell proliferation was quantified by MTT, cell counts and nude mouse tumorigenicity assay. The results showed that WIPI1 promotes osteosarcoma cell proliferation.

Do Not Miss the Tumor: A Novel Presentation of Osteosarcoma

Antalgic gait is a common clinical presentation among pediatric patients and can have many different etiologies, with rare life-threatening etiologies including primary bone malignancies. Osteosarcoma is the most common primary malignancy of bone in pediatric and adolescent patients. The incidence rate of osteosarcoma has been reported as high as 5 to 7 per million among patients 19 years old or younger with males slightly more affected than females and African-Americans more than other racial groups. This report describes the case of a five-year-old African-American female who presented with an antalgic gait secondary to osteosarcoma in the left distal femur and follows her through treatment. In this case, the age is atypical as the peak incidence for osteosarcoma is around 16 years of age and is postulated to coincide with growth spurts. Osteosarcoma can have a range of presentations making it difficult to diagnose, which can cause delays in treatment and potential poor patient outcomes. Due to this, such a diagnosis must be included in the differential for patients presenting with antalgic gait. Because primary-care physicians and pediatricians may be the first medical providers to encounter patients with osteosarcoma, it is imperative that such clinicians are familiar with the signs and symptoms associated with osteosarcomas in order to reduce the risk of metastasis and disease progression and prevent treatment delays. Additionally, we believe these clinicians should have a low threshold to refer patients to orthopedists or oncologic specialists in the cases of persistent pain or inconsistencies with history, physical exam, and diagnostic studies. Finally, direct communication and discussion between radiologists and referring clinicians helps decrease delays in diagnosing of osteosarcoma and other life-threatening conditions.

Osteosarcoma: A comprehensive review of management and treatment strategies

Osteosarcoma, a bone cancer usually seen in children and young adults, is generally a high-grade malignancy presented by extreme metastases to the lungs. Osteosarcoma has a tendency for appearing in bones with rapid growth rate. The etiology of osteosarcoma is multifaceted and poorly understood. A molecular consideration of this disease will lead to a directed tumor treatment. The present treatment for osteosarcoma comprises of an arrangement of systemic chemotherapy and wide surgical resection. Survival rate is increased by the progress of destructive systemic chemotherapies. So, the development of new treatment approaches for metastatic osteosarcoma is essential. Immunomodulation has been used in clinical settings. Through targeting surface antigens expressed on tumor cells, particular antibodies and exploitation of cellular immunotherapy against sarcomas have been confirmed to be effective as cancer therapeutics. In this article, we have reviewed epidemiology, etiology, pathogenesis, diagnosis, and treatment of osteosarcoma and we have focused on different methods of immunotherapy including vaccines, cell-based immunotherapy, cytokines, and monoclonal antibodies.

Silencing hsa_circRNA_0008035 exerted repressive function on osteosarcoma cell growth and migration by upregulating microRNA-375

Traditionally, circular RAN hsa_circ_0008035 was proven to function as a tumor inhibitor in gastric cancer. Nevertheless, much less was known about hsa_circ_0008035 in osteosarcoma (OSA). This project was undertaken to assess the role of hsa_circ_0008035 in OSA. Hsa_circ_0008035 level in serum of OSA patients, OSA tissues and cell lines were measured by reverse transcription-quantitative PCR. After downregulation or overexpression of hsa_circ_0008035, cell proliferation, apoptosis and migration were tested in MG63, SAOS-2 or hFOB1.19 cells. Meanwhile, the expression level of miR-375 was analyzed. The binding between hsa_circ_0008035 and miR-375 was confirmed using bioinformatics and luciferase assay. Subsequently, the effects of miR-375 inhibition on MG63 cell growth and migratory potential were reevaluated. Eventually, the activating status of Notch pathway was assessed by Western blot. Our results demonstrated that hsa_circ_0008035 was overexpressed in serum of OSA patients, OSA tissues and cells. Silencing hsa_circRNA_0008035 impeded OSA cell growth and migration, while hsa_circ_0008035 facilitated cell behaviors of hFOB1.19 cells. Additionally, hsa_circ_0008035 negatively modulated miR-375 expression. Meanwhile, miR-375 inhibition overturned the suppressive effects of silencing hsa_circRNA_0008035 on OSA cell behaviors. Furthermore, silencing hsa_circ_0008035 perturbed Notch pathway by adjusting miR-375 expression. In conclusion, silencing hsa_circRNA_0008035 exerted repressive function on OSA cell growth and migration and Notch pathway by accelerating miR-375.

Construction and Validation of Nomograms for Predicting the Prognosis of Juvenile Osteosarcoma: A Real-World Analysis in the SEER Database

BACKGROUND

Osteosarcoma is one of the most common malignant bone tumors, with a high incidence in adolescence. The objective of this study was to construct prognostic nomograms for predicting the prognosis of juvenile osteosarcoma.

METHODS

Patients with osteosarcoma diagnosed between 2004 and 2015 were identified in the Surveillance, Epidemiology, and End Results (SEER) database. The essential clinical predictors were identified with univariate and multivariate Cox analysis. Nomograms were constructed to predict the 3- and 5-year cancer- specific survival (CSS) and overall survival (OS). Concordance index (C-index) and calibration plots were performed to validate the predictive performance of nomograms.

RESULTS

We enrolled 736 adolescents with osteosarcoma from the SEER database, with 516 samples grouped into a training cohort and 220 samples grouped into a validation cohort. In multivariate analysis of the training cohort, predictors including tumor size, surgery treatment and AJCC stage were found to be associated with OS and CSS, while age was only associated with CSS. Construction of nomograms based on these predictors was performed to evaluate the prognosis of adolescents with osteosarcoma. The C-index and calibration curves also showed the satisfactory performance of these nomograms for prognosis prediction.

CONCLUSION

The developed nomograms are useful tools for precisely predicting the prognosis of adolescents with osteosarcoma, which could enable patients to be more accurately managed in clinical practice.