Malignant Bone Tumors Research Articles

Surgical and Oncologic Outcome following Sacrectomy for Primary Malignant Bone Tumors and Locally Recurrent Rectal Cancer.

Bone sarcoma or direct pelvic carcinoma invasion of the sacrum represent indications for partial or total sacrectomy. The aim was to describe the oncosurgical management and complication profile and to analyze our own outcome results following sacrectomy. In a retrospective analysis, 27 patients (n = 8/10/9 sarcoma/chordoma/locally recurrent rectal cancer (LRRC)) were included. There was total sacrectomy in 9 (incl. combined L5 en bloc spondylectomy in 2), partial in 10 and hemisacrectomy in 8 patients. In 12 patients, resection was navigation-assisted. For reconstruction, an omentoplasty, VRAM-flap or spinopelvic fixation was performed in 20, 10 and 13 patients, respectively. With a median follow-up (FU) of 15 months, the FU rate was 93%. R0-resection was seen in 81.5% (no significant difference using navigation), and 81.5% of patients suffered from one or more minor-to-moderate complications (especially wound-healing disorders/infection). The median overall survival was 70 months. Local recurrence occurred in 20%, while 44% developed metastases and five patients died of disease. Resection of sacral tumors is challenging and associated with a high complication profile. Interdisciplinary cooperation with visceral/vascular and plastic surgery is essential. In chordoma patients, systemic tumor control is favorable compared to LRRC and sarcomas. Navigation offers gain in intraoperative orientation, even if there currently seems to be no oncological benefit. Complete surgical resection offers long-term survival to patients undergoing sacrectomy for a variety of complex diseases.

Advancements in Image Enhancement and Attention based EfficientDet Optimization Classifier for Precise Osteosarcoma Lung Nodule Detection

Introduction: Osteosarcoma is a malignant bone tumor that frequently spreads to the lungs, hence therapy effectiveness depends on early identification. However, noise and subtle characteristics still pose a challenge for reliable Lung Nodules Detection (LND) in medical pictures. In earlier work, SSD-VGG16 was implemented to provide a bounding box with an accuracy score that represented a single osteosarcoma nodule. Increasing model complexity is sometimes necessary to achieve improved accuracy with current approaches, which might worsen their computing inefficiencies.Methods: For accurate osteosarcoma lung nodule identification, this study offers the hybrid Dynamic Virtual Bats Algorithm with Attention based Efficient Object identification (A- EfficientDet). In order to improve the quality and informativeness of clinical pictures, this study suggests including Chebyshev filtering into the pre-processing pipeline. It focuses on CT scans for the purpose of detecting lung nodules associated with osteosarcoma. Additionally, provide the optimized A-EfficientDet model, a hybrid EfficientDet model improved using the DVBA optimization technique for accurate lung nodule identification. Results: The effectiveness of the suggested strategy in attaining accurate osteosarcoma LND is demonstrated by the experimental findings. Chebyshev filtering is incorporated during the pre-processing step, which leads to more accurate detection findings by improving the signal-to-noise ratio (SNR) and lung nodule visibility. Conclusion: Additionally, the improved EfficientDet model demonstrates its suitability for clinical applications in early osteosarcoma detection and treatment monitoring by achieving (SOTA) State-Of-The-Art execution by the metrics of sensitivity, specificity, and F1 score.

Ulnar bone tuberculosis in children: Case report and literature review.

Tuberculosis of the long tubular bones in children's extremities is infrequent, particularly in the ulna. Early diagnosis poses significant challenges. This report presents a case involving a 2-year-old child with tuberculosis of the ulnar bone, accompanied by a comprehensive review of pertinent literature. The purpose of this study is to share diagnostic and therapeutic experiences and provide potentially valuable insights. In this case, the patient exhibited complete destruction and expansion of the ulnar bone, resulting in a forearm size considerably greater than normal. Concerns were raised about the irreversible deformation of the ulna, the potential for a malignant bone tumor, and its impact on forearm function, potentially endangering the patient's life. The diagnosis was confirmed as tuberculosis of the ulnar bone. The patient underwent surgery to remove the affected ulnar tissue and received anti-tuberculosis medication. Subsequent to treatment, the destruction and expansion of the ulnar bone resolved, with the return of normal ulnar morphology and bone structure. Even in the absence of typical symptoms like fever, weight loss, and loss of appetite, extensive destruction and expansion of a long tubular bone should prompt vigilant consideration of bone tuberculosis.

Not every knee tumour is a ganglion - retrospective analysis of benign and malign tumour entities around the knee.

Due to a lack of routine, there is often uncertainty regarding diagnostics of tumours around the knee joint. This study aimed to provide knowledge about the frequency, distribution and diagnostic algorithm of different bone and soft tissue tumour entities of the knee at a large referral university hospital in Germany. Retrospective, longitudinal, single-centre study that reviewed adult patients from 2010 until 2020 with a suspected tumours diagnosis around the knee at a university cancer centre. Inclusion criteria were adults with true bone or soft-tissue tumours in the knee joint and in its adjacent compartments. Suspected diagnosis, histological tumour entity, localization and its surgical treatment by biopsy, resection, osteosynthesis or tumour endoprosthesis were investigated. A total number of 310 adult patients were included with a mean age of 54.2 ± 18.8 years. In total 160 (51.6%) soft-tissue tumours (69/43.1% benign; 74/46.2% malignant; 17/10.6% intermediate), 92 (29.6%) primary bone tumours (46/50% benign; 39/42.3% malignant; 7/7.6% intermediate), 36 (11.6%) metastases and 22 (7.1%) lymphomas were detected. 171 (55.1%) tumours were classified as malignant. Suspected diagnosis was matched with histology in 74.5% (231/310) of all cases. In 6 cases a primarily suspected benign diagnosis turned out to be malignant. The majority of primary bone tumours was cartilage derived (63.1%;58/92) and located in the distal 2/3 of the femur, whereas intracapsular tumours of the knee joint were rare (13.0%). Soft-tissue tumours were located primarily in the middle third of the thigh (36.8%). The MRI was the diagnostic tool of choice in 98.1% of soft tissue tumours and 82.6% bone tumours. Awareness is crucial for detecting rare and malignant tumours around the knee, with adipocytic tumours being the most common soft tissue tumour and chondrogenic tumours as the most prevalent malignant bone tumour. Accurate diagnosis of bone tumours necessitates radiographs and frequently an additional MRI scan, while soft tissue tumours require mandatory MRI scans. Incorrectly diagnosing a tumour can have severe consequences, emphasizing the need for histological confirmation in all cases. Additionally, malignant tumours within joint capsules in adults are infrequent.

The role of serum interleukins in Cancer: A Multi-center Mendelian Randomization study

The occurrence of cancer is often accompanied by immune evasion and tumor-promoting inflammation, with interleukins (IL) playing a pivotal role in the immune-inflammatory mechanism. However, the precise contribution of serum interleukins in cancer remains elusive. We obtained GWAS summary data for 35 interleukins from eight independent large-scale serum proteome studies of European ancestry populations and for 23 common cancers from the FinnGen Consortium. We then conducted a multicenter Mendelian Randomization (MR) study to explore the relationship between systemic inflammatory status and cancers. 24 causal associations between interleukins and cancers were supported by multicenter data, 18 of which were reported for the first time. Our results indicated that IL-1α (Hodgkin lymphoma), IL-5 (bladder cancer), IL-7 (prostate cancer), IL-11 (bone malignant tumor), IL-16 (lung cancer), IL-17A (pancreatic cancer), IL-20 (bladder cancer), IL-22 (lymphocytic leukemia), IL-34 (breast cancer), IL-36β (prostate cancer), and IL-36γ (liver cancer) were risk factors for related cancers. Conversely, IL-9 (malignant neoplasms of the corpus uteri), IL-17C (liver cancer), and IL-31 (colorectal cancer, bladder cancer, pancreatic cancer, and cutaneous melanoma) exhibited protective effects against related cancers. Notably, the dual effects of serum interleukins were also observed. IL-18 acted as a risk factor for prostate cancer, however, was a protective factor against laryngeal cancer. Similarly, IL-19 promoted the development of lung cancer and myeloid leukemia, while conferring protection against Breast, cervical, and thyroid cancers. Our study confirmed the genetic association between multiple serum interleukins and cancers. Immune and anti-inflammatory strategies targeting these associations provide opportunities for prevention and treatment.

MATN4 as a target gene of HIF-1α promotes the proliferation and metastasis of osteosarcoma.

Osteosarcoma is a highly malignant bone tumor that exhibits rapid growth and early metastasis. Hypoxia plays a pivotal role in promoting the proliferation and metastasis of osteosarcoma through a series of molecular events, which are partially mediated and regulated by HIF-1α. However, the regulatory network associated with HIF-1α in osteosarcoma remains limited. Therefore, the objective of this study was to identify critical hypoxia-associated genes and investigate their effects and molecular mechanisms in osteosarcoma cells. Through bioinformatics analysis, matrilin-4 (MATN4) was identified as a crucial gene associated with hypoxia. The expression of MATN4 and HIF-1α was assessed using immunohistochemistry, RT-qPCR, and western blotting. The proliferative capacity of osteosarcoma cells was assessed through the utilization of CCK-8, EDU staining, and colony formation assays. The effects of MATN4 on the mobility of OS cells were evaluated using wound-healing assays and transwell assays. The interaction between MATN4 and HIF-1α was detected through chromatin immunoprecipitation. MATN4 is overexpressed in osteosarcoma tissue and cells, particularly in osteosarcoma cells with high metastatic potential. Knockdown of MATN4 inhibits the proliferation, migration, and invasion abilities of osteosarcoma cells and reverses the promoting effects of hypoxia on these functions. Additionally, HIF-1α binds to MATN4 and upregulates its expression. Interestingly, knockdown of HIF-1α reduces the stimulatory effects of MATN4 overexpression on the proliferation, migration, and invasion of osteosarcoma cells under hypoxic conditions. Taken together, our results suggest that MATN4 is regulated by HIF-1α and confers a more aggressive phenotype on OS cells. This evidence suggests that MATN4 may act as a potential target for OS diagnosis and treatment.

Osteosarcoma associated with cemento-osseous dysplasia: co-incidence or two related entities?

BackgroundOsteosarcoma of the jaws is a rare primary malignant tumor of bone. The clinical, radiological and histopathological features of a case associated with cemento-osseous dysplasia is presented.Case ReportA 57-year-old mixed-race female presented with a large, progressive, swelling of the right mandible. Radiographic examination revealed two associated lesions. Partially defined irregular radiopacities were noted in the left mandible, extending from the premolar to the molar region. The lesion had a cotton-wool appearance and resembled a fibro-osseous lesion; i.e. cemento-osseous dysplasia. A second large, expansive and irregular, radiopaque lesion was noted on the right angle of the mandible, extending beyond the inferior cortex of the mandible. The internal structure was heterogeneous and resembled irregular bone formation. The classic “sunburst” appearance of radiating bony spicules can be seen in the posterior–anterior view and the CBCT 3D reconstruction, indicating the outgrowth of the tumor matrix. Histopathological exam confirmed a final diagnosis of osteosarcoma closely associated with cemento-osseous dysplasia. The patient underwent a fludeoxyglucose-18 (FDG) positron emission tomography (PET) scan which indicated metastasis in the left lung and increased uptake in the right mandible. Chemotherapy was initially administered with a plan to resect the tumor, however, the patient demised as a result of medical complications.ConclusionThe question in the literature remains whether these two entities are coincidentally found or arise from each other. Nevertheless, it is important for clinicians to closely monitor patients with cemento-osseous dysplasia and biopsy any suspicious lesions that may develop into osteosarcoma.

Nanoengineered 3D-printing scaffolds prepared by metal-coordination self-assembly for hyperthermia-catalytic osteosarcoma therapy and bone regeneration

The integration of functional nanomaterials with tissue engineering scaffolds has emerged as a promising solution for simultaneously treating malignant bone tumors and repairing resected bone defects. However, achieving a uniform bioactive interface on 3D-printing polymer scaffolds with minimized microstructural heterogeneity remains a challenge. In this study, we report a facile metal-coordination self-assembly strategy for the surface engineering of 3D-printed polycaprolactone (PCL) scaffolds with nanostructured two-dimensional conjugated metal–organic frameworks (cMOFs) consisting of Cu ions and 2,3,6,7,10,11-hexahydroxytriphenylene (HHTP). A tunable thickness of Cu-HHTP cMOF on PCL scaffolds was achieved via the alternative deposition of metal ions and HHTP. The resulting composite PCL@Cu-HHTP scaffolds not only demonstrated potent photothermal conversion capability for efficient OS ablation but also promoted the bone repair process by virtue of their cell-friendly hydrophilic interfaces. Therefore, the cMOF-engineered dual-functional 3D-printing scaffolds show promising potential for treating bone tumors by offering sequential anti-tumor effects and bone regeneration capabilities. This work also presents a new avenue for the interface engineering of bioactive scaffolds to meet multifaceted demands in osteosarcoma-related bone defects.

Preliminary exploration of amide proton transfer weighted imaging in differentiation between benign and malignant bone tumors.

To explore the value of 3D amide proton transfer weighted imaging (APTWI) in the differential diagnosis between benign and malignant bone tumors, and to compare the diagnostic performance of APTWI with traditional diffusion-weighted imaging (DWI). Patients with bone tumors located in the pelvis or lower limbs confirmed by puncture or surgical pathology were collected from January 2021 to July 2023 in the First Affiliated Hospital of Zhengzhou University. All patients underwent APTWI and DWI examinations. The magnetization transfer ratio with asymmetric analysis at the frequency offset of 3.5 ppm [MTRasym(3.5 ppm)] derived by APTWI and the apparent diffusion coefficient (ADC) derived by DWI for the tumors were measured. The Kolmogorou-Smirnou and Levene normality test was used to confirm the normal distribution of imaging parameters; and the independent sample t test was used to compare the differences in MTRasym(3.5 ppm) and ADC between benign and malignant bone tumors. In addition, the receiver operating characteristic (ROC) curve was used to evaluate the diagnostic performance of different imaging parameters in differentiation between benign and malignant bone tumors. P<0.05 means statistically significant. Among 85 bone tumor patients, 33 were benign and 52 were malignant. The MTRasym(3.5 ppm) values of malignant bone tumors were significantly higher than those of benign tumors, while the ADC values were significantly lower in benign tumors. ROC analysis shows that MTRasym(3.5 ppm) and ADC values perform well in the differential diagnosis of benign and malignant bone tumors, with the area under the ROC curve (AUC) of 0.798 and 0.780, respectively. Combination of MTRasym(3.5 ppm) and ADC values can further improve the diagnostic performance with the AUC of 0.849 (sensitivity = 84.9% and specificity = 73.1%). MTRasym(3.5 ppm) of malignant bone tumors was significantly higher than that of benign bone tumors, reflecting the abnormal increase of protein synthesis in malignant tumors. APTWI combined with DWI can achieve a high diagnostic efficacy in differentiation between benign and malignant bone tumors.

Treatment algorithm for metastatic malignancies in the lower extremities.

A high prevalence of proximal femoral metastases persists in patients with cancer, particularly regarding lower extremity fractures. This study offers a detailed analysis of clinical characteristics of patients undergoing surgical treatment for pathological or impending fractures, enhancing treatment strategies for metastatic malignancies. A total of thirty patients who underwent treatment of impending and pathological fractures at Kindai University Hospital (Osakasayama, Japan) were included. The retrospective study comprised parameters including age, sex, fracture site, type of primary malignancy, number of metastases, pre-fracture Eastern Cooperative Oncology Group performance status (ECOG-PS) score, adjuvant therapy, treatment modality, operative time, blood loss, postoperative complications, Musculoskeletal Tumor Society (MSTS) score, outcome and follow-up period. Post-treatment MSTS scores were compared in cases of impending and pathological fractures, and between intramedullary nailing and other surgical procedures. In addition, one-year postoperative survival rates were calculated. Furthermore, operative time, blood loss and survival rates were compared between impending and pathological fractures. The participants' median age was 70.5 years, with disease sites primarily in the subtrochanteric femur, trochanteric femur, femoral diaphysis, femoral neck and other locations. Pathologies included multiple myeloma and unknown primary, lung, breast, kidney, liver, gastric, esophageal and uterine cancers. The median ECOG-PS score pre-fracture was 2. Treatment approaches involved radiotherapy, chemotherapy and a combination of both. Surgical interventions included intramedullary nailing (16 cases), endoprosthesis (1 case), bipolar head replacement (3 cases) and compression hip screw (3 cases), among others. A negative correlation (R=-0.63) existed between MSTS and pre-fracture ECOG-PS scores. The operative time was significantly shorter in impending than in pathological fractures, with impending fractures showing significantly lower blood loss. The treatment algorithm for malignant bone tumors of the lower extremity provided in the present study was efficient, potentially optimizing treatment strategies for such cases, and contributing to improved patient care and outcomes in oncology and orthopedic surgery.

System analysis based on Anoikis-related genes identifies MAPK1 as a novel therapy target for osteosarcoma with neoadjuvant chemotherapy

BackgroundOsteosarcoma (OS) is the most common bone malignant tumor in children, and its prognosis is often poor. Anoikis is a unique mode of cell death.However, the effects of Anoikis in OS remain unexplored.MethodDifferential analysis of Anoikis-related genes was performed based on the metastatic and non-metastatic groups. Then LASSO logistic regression and SVM-RFE algorithms were applied to screen out the characteristic genes. Later, Univariate and multivariate Cox regression was conducted to identify prognostic genes and further develop the Anoikis-based risk score. In addition, correlation analysis was performed to analyze the relationship between tumor microenvironment, drug sensitivity, and prognostic models.ResultsWe established novel Anoikis-related subgroups and developed a prognostic model based on three Anoikis-related genes (MAPK1, MYC, and EDIL3). The survival and ROC analysis results showed that the prognostic model was reliable. Besides, the results of single-cell sequencing analysis suggested that the three prognostic genes were closely related to immune cell infiltration. Subsequently, aberrant expression of two prognostic genes was identified in osteosarcoma cells. Nilotinib can promote the apoptosis of osteosarcoma cells and down-regulate the expression of MAPK1.ConclusionsWe developed a novel Anoikis-related risk score model, which can assist clinicians in evaluating the prognosis of osteosarcoma patients in clinical practice. Analysis of the tumor immune microenvironment and chemotherapeutic drug sensitivity can provide necessary insights into subsequent mechanisms. MAPK1 may be a valuable therapeutic target for neoadjuvant chemotherapy in osteosarcoma.

Oncology

The June 2024 Oncology Roundup360 looks at: Chondrosarcoma of the femur: is local recurrence influenced by the presence of an extraosseous component?; Diagnostic challenges in low-grade central osteosarcoma; Single osteotomy technique for frozen autograft (pedicled freezing) in patients with malignant bone tumours; Unplanned resection for small superficial soft-tissue sarcomas: disastrous or simply bad?; Inactivation and replantation of the knee joint: an infeasible surgical method; Active surveillance of diffuse-type tenosynovial giant cell tumours: a retrospective, multicentre cohort study.

Predictors of pulmonary metastases on chest computed tomography in children and adolescents with osteosarcoma—tips for qualifying patients for thoracotomy

BackgroundOsteosarcoma is the most common primary malignant bone tumour in children and adolescents. Lungs are the most frequent and often the only site of metastatic disease. The presence of pulmonary metastases is a significant unfavourable prognostic factor. Thoracotomy is strongly recommended in these patients, while computed tomography (CT) remains the gold imaging standard. The purpose of our study was to create tools for the CT-based qualification for thoracotomy in osteosarcoma patients in order to reduce the rate of useless thoracotomies.MethodsSixty-four osteosarcoma paediatric patients suspected of lung metastases on CT and their first-time thoracotomies (n = 100) were included in this retrospective analysis. All CT scans were analysed using a compartmental evaluation method based on the number and size of nodules. Calcification and location of lung lesions were also analysed. Inter-observer reliability between two experienced radiologists was assessed. The CT findings were then correlated with the histopathological results of thoracotomies. Various multivariate predictive models (logistic regression, classification tree and random forest) were built and predictors of lung metastases were identified.ResultsAll applied models proved that calcified nodules on the preoperative CT scan best predict the presence of pulmonary metastases. The rating of the operated lung on the preoperative CT scan, dependent on the number and size of nodules, and the total number of nodules on this scan were also found to be important predictors. All three models achieved a relatively high sensitivity (72–92%), positive predictive value (81–90%) and accuracy (74–79%). The positive predictive value of each model was higher than of the qualification for thoracotomy performed at the time of treatment. Inter-observer reliability was at least substantial for qualitative variables and excellent for quantitative variables.ConclusionsThe multivariate models built and tested in our study may be useful in the qualification of osteosarcoma patients for metastasectomy through thoracotomy and may contribute to reducing the rate of unnecessary invasive procedures in the future.

Research

The June 2024 Research Roundup360 looks at: Do the associations of daily steps with mortality and incident cardiovascular disease differ by sedentary time levels?; Large-scale assessment of ChatGPT in benign and malignant bone tumours imaging report diagnosis and its potential for clinical applications; Long-term effects of diffuse idiopathic skeletal hyperostosis on physical function: a longitudinal analysis; Effect of intramuscular fat in the thigh muscles on muscle architecture and physical performance in the middle-aged females with knee osteoarthritis; Preoperative package of care for osteoarthritis an opportunity not to be missed?; Superiority of kinematic alignment over mechanical alignment in total knee arthroplasty during medium- to long-term follow-up: a meta-analysis and trial sequential analysis.

Epidemiology of bone tumors in children and adolescents: a retrospective study of 266 patients in the south of Tunisia.

Although bone tumors (BT) are relatively uncommon among the human neoplasm, they constitute the most frequent tumors in children and adolescents (CAA). Little information is available about the epidemiologic features of BT in CAA. We aimed to present and discuss epidemiological characteristics of BT in CAA in southern Tunisia, regarding the different histological types. This is a retrospective study including cases of BT in CAA collected in the pathology department at the Habib Bourguiba university hospital over a period of 15 years (2006- 2020). A total of 266 BT was diagnosed in our institution (42,7% among all BT in Southern Tunisia) divided into 200 benign bone tumors (BBT) (75,2%) and 66 malignant bone tumors (MBT) (24,8%). The mean age for all BT was 14,2 years (3-20 years) with male predominance (sex ratio: 1,48). The most common tumor was osteochondroma (42.2%) followed by osteosarcoma (14.6%) and Ewing sarcoma (6.4%). For BBT, the most affected age group was the 16 to 20 year - old - group (50,7%) with a male predominance (59.8%) and a predilection for lower limb (66.8%) then the upper limb (16,8%). Osteochondroma was the most common histological type (56.5%) followed by aneuvrysmal cyst (8,5%) and osteoid osteoma (6,5%). For MBT, the mean age was 12,5 years (5-20 years) and the most affected age group was the 11 to 15 year -old -group (59%). Boys were more affected (60.6%), with a preference for the lower limb (57%) followed by the pelvis (15,6%). Osteosarcoma was the most common MBT (60%) followed by Ewing sarcoma (24%). Given their rarity and heterogeneity, the diagnosis of BT is particular in CAA and requires a multidisciplinary approach. The reporting of epidemiological studies remains essential in order to expand our knowledge regarding these uncommon tumors.

Fear of cancer recurrence in adolescent patients with malignant bone tumors: a cross-section survey

BackgroundAdolescent malignant-bone tumor patients' fear of cancer recurrence is a significant psychological issue, and exploring the influencing factors associated with fear of cancer recurrence in this population is important for developing effective interventions. This study is to investigate the current status and factors influencing fear of cancer recurrence (FCR) related to malignant bone-tumors in adolescent patients, providing evidence for future targeted mental health support and interventions.DesignA cross-sectional survey.MethodsIn total, 269 adolescent malignant-bone tumor cases were treated at two hospitals in Zhejiang Province, China from January 2023 to December 2023. Patients completed a General Information Questionnaire, Fear of Progression Questionnaire-Short Form (FoP-Q-SF), Family Hardiness Index (FHI), and a Simple Coping Style Questionnaire (SCSQ). Univariate and multivariable logistic regressions analysis were used to assess fear of cancer recurrence.ResultsA total of 122 (45.4%) patients experienced FCR (FoP-Q-SF ≥ 34). Logistic regression analysis analyses showed that per capita-monthly family income, tumor stage, communication between the treating physician and the patient, patient's family relationships, family hardiness a positive coping score, and a negative coping score were the main factors influencing FCR in these patients (P < 0.05).ConclusionsFCR in malignant-bone tumor adolescent patients is profound. Healthcare professionals should develop targeted interventional strategies based on the identified factors, which affect these patients; helping patients increase family hardiness, helping patients to positively adapt, and avoid negative coping styles.

Analysis of demographic and socioeconomic factors in adamantinoma using data from the National Cancer Database (NCDB).

e23501 Background: Adamantinoma is a rare low-grade primary malignant bone tumor accounting for less than 1% of all malignant bone tumors. It largely presents in the tibia of young adults, is locally aggressive, and can metastasize. Definitive diagnosis is primarily established by histopathological examination. This rare tumor with uncertain histogenesis remains under-studied. Therefore, exploring trends in diagnoses may provide insight into its epidemiology. The National Cancer Database (NCDB) was examined to reveal the demographic factors in patients diagnosed with Adamantinoma. Methods: A retrospective cohort analysis utilizing the 2004–2020 NCDB included 206 patients with a histologically-confirmed diagnosis of adamantinoma (ICD-O-3 Code 9261). Demographic factors such as age, sex, race, Hispanic status, insurance status, facility type, distance from facility, and Charlson-Deyo score were analyzed via descriptive statistics. Trends in incidence were interpreted using regression analysis. Results: A total of 206 patients were identified in the NCDB with a confirmed diagnosis of adamantinoma of long bones between 2004-2020. Incidence remained relatively stable over this time period (R² = 0.009). The most common primary site of diagnosis were the long bones of lower limb and associative joints (97%). Most individuals (88%) had a Charlson-Deyo comorbidity score of 0. The majority of patients (66%) were classified as Stage 1 AJCC staging. Men were more likely to be diagnosed (56%) compared to women (44%). Most patients were White (78%) and non-Hispanic (85%). A higher percentage of patients were privately insured (67%) and lived in metropolitan areas (87%). Treatment facilities primarily were academic programs (74%). Almost all of the patients were treated surgically (92%) with the most common approach being lymph node dissection (61%) more so than local tumor excision or removal of adjacent organs. Following surgery, the patients observed had a very good prognosis, with a 99% ninety-day survival, a 93% five-year survival, and an 89% ten-year survival. Conclusions: Adamantinoma has a risk for recurrent and metastatic disease. This first NCDB analysis on adamantinoma’s demographics addresses a significant knowledge gap on this topic. The primary site of diagnosis were lower extremity long bones, most commonly treated with surgical intervention, and had a high survival rate which is consistent with earlier studies. The majority of patients included in this study tend to be White, non-Hispanic, and privately insured. This may suggest a demographic and socioeconomic factor that plays a part in diagnosis, prognosis, and treatment of individuals with adamantinoma. Future research should focus on the understanding of factors that impact the course of one’s health and the etiology of this rare pathology.

Lower Plasma Selenium Level in Primary Malignant Bone Tumors: A Survey Research

Objective: To compare plasma selenium levels in primary bone tumor patients with clinically healthy Thai subjects. Materials and Methods: A cross-sectional study on plasma selenium of primary bone tumor patients aged above 12 years old was obtained at Siriraj Hospital. The plasma samples were used for selenium assay by Electrothermal Atomic Absorption spectrometry method. The plasma selenium levels were compared with the clinically healthy Thai subjects or within primary bone tumor groups (age: below or above 30 years, gender: male or female, benign or malignant tumor, metastasis or non-metastasis). Results: One hundred and nine primary bone tumor patients were included in this study. Plasma selenium level in clinically healthy Thai subjects aged more than 30 years old was significantly higher than a primary bone tumor group (121.71 ± 19.96 g/L vs 111.88 ± 23.62 g/L, mean difference -9.83, p-value = 0.017). The plasma selenium levels within the primary bone tumor patients did not exhibit significant differences when compared across genders, age groups below and above 30 years old, benign and malignant tumors, or between metastatic and non-metastatic tumor cases. Conclusion: A patient with a history of malignant bone tumors tends to have a lower level of plasma selenium than normal people. However, the study of selenium supplementation for those who have a higher risk of developing malignant bone tumors is needed in the future.

Understanding clonal heterogeneity and mechanisms of methotrexate resistance in two osteosarcoma PDX models.

e23512 Background: Osteosarcoma is a primary malignant bone tumor that is known to have significant intratumoral heterogeneity with branched cancer evolution. The lung is the most frequent site of metastatic disease and relapse occurs in more than 30 % children and young adults. It has been revealed that the metastatic ability and resistance of cancers including osteosarcoma might be due to the presence of a subset of cells within the intra-tumorally heterogeneous population. We investigated the emergence of resistant clonal subpopulations following targeted methotrexate treatment in two patient derived xenograft (PDX) models in vitro and in vivo. Our aim was to not only track the subclonal population of cells that establish in the lungs but also to identify clonal drivers and the mutational signature of the genes and pathways involved in MTX resistance. Methods: We previously established 20 barcoded osteosarcoma PDX models and demonstrated that the application of methotrexate (MTX-IC95) treatment as a selective pressure in seven models produces clonal subpopulations that were more resistant to MTX. In the current work we used barcoded next generation and RNA sequencing techniques to map the clonal and transcriptomic architecture of MTX resistant single clones in M36 and OS252 PDX models. We next injected the barcoded PDX cells intratibially in twenty severe combined immunodeficiency disease (SCID) mice to track the clonal population/subpopulation of cells that metastasize to the lungs. Following primary tumor growth, limb amputation was carried out and mice were treated with methotrexate or vehicle for two weeks. Primary tumor, blood and lung samples were collected after death from metastasis or euthanasia. All samples collected were snap frozen in liquid nitrogen and stored at -800C. DNA and RNA was extracted and analyzed by PCR, NGS or WES to map clonality, mutational and evolutionary profiles. Results: MTX treated single clones showed diversity and barcode abundance when compared to vehicle; barcode abundance reduced in the resistant clonal subpopulations when compared to the vehicles. Ten unique subclones were shared in both vehicle and MTX resistant clones in M36 while OS252 had only one shared subclone respectively. More than 50% of the injected mice developed primary tumors and matched lung micrometastases. We are currently analyzing both targeted and RNA sequencing results to further understand clonality, the mutational signature of the genes (DHFR, MTR, FPGS, GGH) and pathways involved in MTX resistance. Conclusions: We investigated mechanism of methotrexate resistance in two barcoded PDX models in vitro and in vivo using cytotoxicity, next generation and RNA sequencing techniques. Targeted amplicon sequencing of key genes involved in antifolate pathway will yield new information on clonal evolution and mechanisms of resistance.

High expression of DEC2 distinguishes chondroblastic osteosarcoma and promotes tumour growth by activating the VEGFC/VEGFR2 signalling pathway

AbstractOsteosarcoma (OS) is the most common primary malignant bone tumour in children and young adults. Account for 80% of all OS cases, conventional OS are characterized by the presence of osteoblastic, chondroblastic and fibroblastic cell types. Despite this heterogeneity, therapeutic treatment and prognosis of OS are essentially the same for all OS subtypes. Here, we report that DEC2, a transcriptional repressor, is expressed at higher levels in chondroblastic OS compared with osteoblastic OS. This difference suggests that DEC2 is disproportionately involved in the progression of chondroblastic OS, and thus, DEC2 may represent a possible molecular target for treating this type of OS. In the human chondroblastic‐like OS cell line MNNG/HOS, we found that overexpression of DEC2 affects the proliferation of the cells by activating the VEGFC/VEGFR2 signalling pathway. Enhanced expression of DEC2 increased VEGFR2 expression, as well as increased the phosphorylation levels at sites Y951 and Y1175 of VEGFR2. On the one hand, activation of VEGFR2Y1175 enhanced cell proliferation through VEGFR2Y1175‐PLCγ1‐PKC‐SPHK‐MEK‐ERK signalling. On the other hand, activation of VEGFR2Y951 decreased mitochondria‐dependent apoptosis rate through VEGFR2Y951‐VARP‐PI3K‐AKT signalling. Activation of these two signalling pathways resulted in enhanced progression of chondroblastic OS. In conclusion, DEC2 plays a pivotal role in cell proliferation and apoptosis‐resistance in chondroblastic OS via the VEGFC/VEGFR2 signalling pathway. These findings lay the groundwork for developing focused treatments that target specific types of OS.