Development Of Bone Metastases Research Articles

Curative-intent surgery for solitary bone metastasis from extremity and trunk wall sarcoma: What are the outcomes and complications?

IntroductionApproximately 40–50 % of sarcoma patients will develop lung metastasis, but only 10 % will develop bone metastasis. The survival benefit of surgery for solitary bone metastasis remains unclear. MethodsFrom 1987 to 2019, 47 patients who underwent curative-intent treatment for localized bone or soft tissue sarcoma in the extremities or trunk wall developed solitary bone metastases as the first distant recurrence. Of them, 51 % (24/47) received curative-intent metastasectomy. We compared the clinicopathologic characteristics of the metastasectomy versus non-metastasectomy patients and evaluated the prognostic impact of solitary bone metastasectomy. The primary outcome measure was disease-specific survival (DSS) after developing solitary bone metastasis. ResultsThe post-metastasis DSS was worse with larger primary tumour size (HR 1.09; 95 % CI 1.02–1.16; p = 0.01) and bone metastasis in the pelvis or spine versus other bones (HR 3.79, 95 % CI 1.46–9.87; p = 0.01), and better with curative-intent surgery for the solitary bone metastasis (HR 0.14; 95 % CI 0.06–0.34; p < 0.001). The median DSS was 43 (95 % CI, 24–69) months for the metastasectomy group vs. 13 (95 % CI, 7–19) months for the non-metastasectomy group (p < 0.001). The metastasectomy group had fewer patients with metastasis in the spine or pelvis and longer metastasis-free interval. In the multivariate analysis, curative-intent surgery for solitary bone metastasis was associated with better survival (HR 0.21; 95 % CI 0.08–0.53; p = 0.001). ConclusionsCurative-intent surgery for solitary bone metastasis from sarcoma is associated with a better prognosis and is a reasonable treatment strategy whenever feasible.

Multimodal Data-Driven Segmentation of Bone Metastasis Lesions in SPECT Bone Scans Using Deep Learning.

Patients with malignant tumors often develop bone metastases. SPECT bone scintigraphy is an effective tool for surveying bone metastases due to its high sensitivity, low-cost equipment, and radiopharmaceutical. However, the low spatial resolution of SPECT scans significantly hinders manual analysis by nuclear medicine physicians. Deep learning, a promising technique for automated image analysis, can extract hierarchal patterns from images without human intervention. To enhance the performance of deep learning-based segmentation models, we integrate textual data from diagnostic reports with SPECT bone scans, aiming to develop an automated analysis method that outperforms purely unimodal data-driven segmentation models. We propose a dual-path segmentation framework to extract features from bone scan images and diagnostic reports separately. In the first path, an encoder-decoder network is employed to learn hierarchical representations of features from SPECT bone scan images. In the second path, the Chinese version of the MacBERT model is utilized to develop a text encoder for extracting features from diagnostic reports. The extracted textual features are then fused with image features during the decoding stage in the first path, enhancing the overall segmentation performance. Experimental evaluation conducted on real-world clinical data demonstrated the superior performance of the proposed segmentation model. Our model achieved a 0.0209 increase in the DSC (Dice Similarity Coefficient) score compared to the well-known U-Net model. The proposed multimodal data-driven method effectively identifies and isolates metastasis lesions in SPECT bone scans, outperforming existing classical deep learning models. This study demonstrates the value of incorporating textual data in the deep learning-based segmentation of lowresolution SPECT bone scans.

Effect of colony‑stimulating factor in the mechanism of bone metastasis development (Review).

Bone metastasis (BM) is a common complication of cancer and contributes to a higher mortality rate in patients with cancer. The treatment of BM remains a significant challenge for oncologists worldwide. The colony‑stimulating factor (CSF) has an important effect on the metastasis of multiple cancers. In vitro studies have shown that CSF acts as a cytokine, promoting the colony formation of hematopoietic cells by activating granulocytes and macrophages. Other studies have shown that CSF not only promotes cancer aggressiveness but also correlates with the development and prognosis of various types of cancer. In recent years, the effect of CSF on BM has been primarily investigated using cellular and animal models, with limited clinical studies available. The present review discussed the composition and function of CSF, as well as its role in the progression of BM across various types of cancer. The mechanisms by which osteoclast‑ and osteoblast‑mediated BM occur are comprehensively described. In addition, the mechanisms of action of emerging therapeutic agents are explored for their potential clinical applications. However, further clinical studies are required to validate these findings.

Bone sialoprotein stimulates cancer cell adhesion through the RGD motif and the αvβ3 and αvβ5 integrin receptors.

Being implicated in bone metastasis development, bone sialoprotein (BSP) expression is upregulated in patients with cancer. While BSP regulates cancer cell adhesion to the extracellular matrix, to the best of our knowledge, the specific adhesive molecular interactions in metastatic bone disease remain unclear. The present study aimed to improve the understanding of the arginine-glycine-aspartic acid (RGD) sequence of BSP and the integrin receptors αvβ3 and αvβ5 in BSP-mediated cancer cell adhesion. Human breast cancer (MDA-MB-231), prostate cancer (PC-3) and non-small cell lung cancer (NSCLC; NCI-H460) cell lines were cultured on BSP-coated plates. Adhesion assays with varying BSP concentrations were performed to evaluate the effect of exogenous glycine-arginine-glycine-aspartic acid-serine-proline (GRGDSP) peptide and anti-integrin antibodies on the attachment of cancer cells to BSP. Cell attachment was assessed using the alamarBlue® assay. The present results indicated that BSP supported the adhesion of cancer cells. The RGD counterpart GRGDSP peptide reduced the attachment of all tested cancer cell lines to BSP by ≤98.4%. Experiments with anti-integrin antibodies demonstrated differences among integrin receptors and cancer cell types. The αvβ5 antibody decreased NSCLC cell adhesion to BSP by 84.3%, while the αvβ3 antibody decreased adhesion by 14%. The αvβ3 antibody decreased PC-3 cell adhesion to BSP by 46.4%, while the αvβ5 antibody decreased adhesion by 9.5%. Adhesion of MDA-MB-231 cells to BSP was inhibited by 54.7% with αvβ5 antibody. The present results demonstrated that BSP-induced cancer cell adhesion occurs through the binding of the RGD sequence of BSP to the cell integrin receptors αvβ3 and αvβ5. Differences between cancer types were found regarding the mediation via αvβ3 or αvβ5 receptors. The present findings may explain why certain cancer cells preferentially spread to the bone tissue, suggesting that targeting the RGD-integrin binding interaction could be a promising novel cancer treatment option.

Development and validation of a diagnostic and prognostic model for bone metastasis of intrahepatic cholangiocarcinoma: a population-based analysis.

Bone metastasis (BM) is a common site of metastasis in patients with intrahepatic cholangiocarcinoma (ICC), significantly impacting the quality of life and prognosis of affected individuals. This investigation aimed to assess the risk of BM development in ICC patients and to prognosticate for patients with ICC-associated BM (ICCBM) through the construction of two nomograms. We conducted a retrospective analysis of data from 2,651 ICC patients, including 148 cases of BM, documented in the Surveillance, Epidemiology, and End Results (SEER) database spanning 2010 to 2017. Independent predictors for the occurrence of BM in ICC patients were identified via univariate and multivariate logistic regression analyses; simultaneously, independent prognostic indicators for ICCBM patients were ascertained through univariate and multivariate Cox regression analyses. The utility of the nomograms was evaluated through calibration curves, receiver operating characteristic (ROC) curves, decision curve analysis (DCA), and Kaplan-Meier (KM) analysis. Independent risk factors for BM in ICC included sex, tumor size, lung metastasis, brain metastasis, and intrahepatic metastasis. For ICCBM patients, independent prognostic factors comprised age, chemotherapy, and radiotherapy. The prognostic nomogram exhibited C-indexes of 0.737 [95% confidential interval (CI): 0.682-0.792] for the training cohort and 0.696 (95% CI: 0.623-0.769) for the validation cohort. Calibration curves demonstrated strong concordance between predicted outcomes and observed events. The areas under the curve (AUC) for 3-, 6-, and 12-month cancer-specific survival (CSS) were 0.853, 0.781, and 0.739, respectively, in the training cohort, and 0.794, 0.822, and 0.780 in the validation cohort. DCA illustrated significant net benefits across a broad spectrum of threshold probabilities. KM analysis revealed 1-, 2-, and 3-year CSS rates of 23.91%, 7.55%, and 2.35%, respectively, with a median CSS of 6 months, underscoring the nomograms' capacity to distinctly stratify patients according to survival risk. The development of these nomograms offers substantial clinical utility in forecasting BM risk among ICC patients and prognosticating for those with ICCBM, thereby facilitating the formulation of more efficacious treatment modalities.

Preoperative platelet distribution width predicts bone metastasis in patients with breast cancer

PurposeBone metastases occur in 50-70% of patients with breast cancer (BC) and result in high mortality. Platelet distribution width (PDW), a commonly used parameter of activated platelets, has been associated with a poor prognosis in BC. We aim to investigate the prognostic role of PDW for bone metastasis in BC patients.Methods515 patients who received BC surgery in the Harbin Medical University Cancer Hospital from July 1, 2016, to December 31, 2017, were reviewed. Patients’ characteristics and platelet indices upon enrollment in this study were collected. The Kaplan-Meier method was used to estimate the 5-year bone metastasis incidence. The univariate and multivariate Cox regression analyses were utilized to identify risk factors associated with bone metastasis.ResultsThe patients with bone metastases exhibited lower PDW levels than the patients without bone metastases. Moreover, decreased PDW was significantly correlated with histologic type, multifocal disease, and lymph node status. In addition, the patients with reduced PDW levels were more likely to develop bone metastasis. Multivariate analysis showed that PDW was an independent predictor for bone metastasis.ConclusionPDW is an independent predictor of bone metastasis in BC. Further research is warranted.

Bioinformatic analysis of differentially expressed genes in lung cancer bone metastasis and their implications for disease progression in lung cancer patients.

Lung cancer is the most commonly diagnosed cancer and the leading cause of cancer-related death worldwide. Moreover, it is highly susceptible to distant metastasis, which is the main cause of pain in advanced lung cancer, and frequently occurs in the bone. This study aimed to identify the differentially expressed genes (DEGs) related to metastatic bone disease in lung cancer using bioinformatics methods and to analyze the risk factors influencing the incidence of secondary bone metastasis in lung cancer. Gene expression profiles from the GSE175601 and GSE10799 datasets in the Gene Expression Omnibus (GEO) database were analyzed to screen for the DEGs associated with lung cancer bone metastasis. The STRING database was used to construct a protein-protein interaction (PPI) network, and the MCODE plugin was used to identify the key genes. The expression of these important genes in lung tumor tissues and their correlation with prognosis were validated in The Cancer Genome Atlas (TCGA) database. An examination of clinical data from patients diagnosed with stage IV lung adenocarcinoma treated at the Anhui No. 2 Provincial People's Hospital was conducted. Immunohistochemistry was used to examine the expression of key genes in lung cancer tumor tissues. A binary logistic regression analysis was conducted to examine the interactions in the expression of critical genes associated with bone metastasis in lung carcinoma patients. In total, 59 DEGs were identified in the GSE175601 and GSE10799 datasets through Venn diagram construction. The PPI network analysis revealed two significant modules and eight candidate genes (LAPTM5, LCP2, CD53, ARHGAP25, C1QA, DES, MYH11, and VIM). According to TCGA database analysis, in carcinogenic tissues of the lung, the expression of these eight critical genes is downregulated. Further, only the lung cancer patients who had high expressions of ARHGAP25 had an improved progress-free interval (PFI) (P<0.05), disease-specific survival (DSS), and overall survival (OS). Of the 49 with stage IV lung adenocarcinoma patients included in the study, 27 (55.10%) developed bone metastasis. The immunohistochemical (IHC) results indicated that the expression score of ARHGAP25 was significantly lower in the group with bone metastasis (3.93±2.95) than the group without bone metastasis (6.64±3.62) (P=0.006). The proportion of patients with low ARHGAP25 expression was significantly higher in the group with bone metastasis (70.37%, 19/27) than the group without bone metastasis (31.82%, 7/22) (P=0.007). The binary logistic regression analysis identified serum alkaline phosphatase (ALP) and ARHGAP25 expression levels as independent risk factors for the occurrence of secondary bone metastatic disease in lung carcinoma patients. The key gene ARHGAP25 identified through bioinformatics for lung cancer bone metastasis was significantly downregulated. Its low expression constitutes an independent risk factor for secondary bone metastatic disease in patients with lung carcinoma.

Bone-metastatic lung adenocarcinoma cells bearing CD74-ROS1 fusion interact with macrophages to promote their dissemination.

Approximately 40% of patients with lung adenocarcinoma (LUAD) often develop bone metastases during the course of their disease. However, scarcely any in vivo model of LUAD bone metastasis has been established, leading to a poor understanding of the mechanisms underlying LUAD bone metastasis. Here, we established a multiorgan metastasis model via the left ventricular injection of luciferase-labeled LUAD cells into nude mice and then screened out lung metastasis (LuM) and bone metastasis (BoM) cell subpopulations. BoM cells exhibited greater stemness and epithelial-mesenchymal transition (EMT) plasticity than LuM cells and initially colonized the bone and subsequently disseminated to distant organs after being reinjected into mice. Moreover, a CD74-ROS1 fusion mutation (C6; R34) was detected in BoM cells but not in LuM cells. Mechanistically, BoM cells bearing the CD74-ROS1 fusion highly secrete the C-C motif chemokine ligand 5 (CCL5) protein by activating STAT3 signaling, recruiting macrophages in tumor microenvironment and strongly inducing M2 polarization of macrophages. BoM cell-activated macrophages produce a high level of TGF-β1, thereby facilitating EMT and invasion of LUAD cells via TGF-β/SMAD2/3 signaling. Targeting the CD74-ROS1/CCL5 axis with Crizotinib (a ROS1 inhibitor) and Maraviroc (a CCL5 receptor inhibitor) in vivo strongly impeded bone metastasis and secondary metastasis of BoM cells. Our findings reveal the critical role of the CD74-ROS1/STAT3/CCL5 axis in the interaction between LUAD bone metastasis cells and macrophages for controlling LUAD cell dissemination, highlighting the significance of the bone microenvironment in LUAD bone metastasis and multiorgan secondary metastasis, and suggesting that targeting CD74-ROS1 and CCL5 is a promising therapeutic strategy for LUAD bone metastasis.

What enlightenment has the development of lung cancer bone metastasis brought in the last 22 years.

Lung cancer bone metastasis (LCBM) is a disease with a poor prognosis, high risk and large patient population. Although considerable scientific output has accumulated on LCBM, problems have emerged, such as confusing research structures. To organize the research frontiers and body of knowledge of the studies on LCBM from the last 22 years according to their basic research and translation, clinical treatment, and clinical diagnosis to provide a reference for the development of new LCBM clinical and basic research. We used tools, including R, VOSviewer and CiteSpace software, to measure and visualize the keywords and other metrics of 1903 articles from the Web of Science Core Collection. We also performed enrichment and protein-protein interaction analyses of gene expression datasets from LCBM cases worldwide. Research on LCBM has received extensive attention from scholars worldwide over the last 20 years. Targeted therapies and immunotherapies have evolved into the mainstream basic and clinical research directions. The basic aspects of drug resistance mechanisms and parathyroid hormone-related protein may provide new ideas for mechanistic study and improvements in LCBM prognosis. The produced molecular map showed that ribosomes and focal adhesion are possible pathways that promote LCBM occurrence. Novel therapies for LCBM face animal testing and drug resistance issues. Future focus should centre on advancing clinical therapies and researching drug resistance mechanisms and ribosome-related pathways.

Intersecting Paths: Unraveling the Complex Journey of Cancer to Bone Metastasis.

The phenomenon of bone metastases presents a significant challenge within the context of advanced cancer treatments, particularly pertaining to breast, prostate, and lung cancers. These metastatic occurrences stem from the dissemination of cancerous cells into the bone, thereby interrupting the equilibrium between osteoblasts and osteoclasts. Such disruption results in skeletal complications, adversely affecting patient morbidity and quality of life. This review discusses the intricate interplay between cancer cells and the bone microenvironment, positing the bone not merely as a passive recipient of metastatic cells but as an active contributor to cancer progression through its distinctive biochemical and cellular makeup. A thorough examination of bone structure and the dynamics of bone remodeling is undertaken, elucidating how metastatic cancer cells exploit these processes. This review explores the genetic and molecular pathways that underpin the onset and development of bone metastases. Particular emphasis is placed on the roles of cytokines and growth factors in facilitating osteoclastogenesis and influencing osteoblast activity. Additionally, this paper offers a meticulous critique of current diagnostic methodologies, ranging from conventional radiography to advanced molecular imaging techniques, and discusses the implications of a nuanced understanding of bone metastasis biology for therapeutic intervention. This includes the development of targeted therapies and strategies for managing bone pain and other skeletal-related events. Moreover, this review underscores the imperative of ongoing research efforts aimed at identifying novel therapeutic targets and refining management approaches for bone metastases. It advocates for a multidisciplinary strategy that integrates advancements in medical oncology and radiology with insights derived from molecular biology and genetics, to enhance prognostic outcomes and the quality of life for patients afflicted by this debilitating condition. In summary, bone metastases constitute a complex issue that demands a comprehensive and informed approach to treatment. This article contributes to the ongoing discourse by consolidating existing knowledge and identifying avenues for future investigation, with the overarching objective of ameliorating patient care in the domain of oncology.

No prognostic impact of staging bone scan in patients with stage IA non-small cell lung cancer.

To investigate the survival benefit of preoperative bone scan in asymptomatic patients with early-stage non-small cell lung cancer (NSCLC). This retrospective study included patients with radical resection for stage T1N0M0 NSCLC between March 2013 and December 2018. During postoperative follow-up, we monitored patient survival and the development of bone metastasis. We compared overall survival, bone metastasis-free survival, and recurrence-free survival in patients with or without preoperative bone scan. Propensity score matching and inverse probability of treatment weighting were used to minimize election bias. A total of 868 patients (58.19 ± 9.69years; 415 men) were included in the study. Of 87.7% (761 of 868) underwent preoperative bone scan. In the multivariable analyses, bone scan did not improve overall survival (hazard ratio [HR] 1.49; 95% confidence intervals [CI] 0.91-2.42; p = 0.113), bone metastasis-free survival (HR 1.18; 95% CI 0.73-1.90; p = 0.551), and recurrence-free survival (HR 0.89; 95% CI 0.58-1.39; p = 0.618). Similar results were obtained after propensity score matching (overall survival [HR 1.28; 95% CI 0.74-2.23; p = 0.379], bone metastasis-free survival [HR 1.00; 95% CI 0.58-1.72; p = 0.997], and recurrence-free survival [HR 0.76; 95% CI 0.46-1.24; p = 0.270]) and inverse probability of treatment weighting. There were no significant differences in overall survival, bone metastasis-free survival, and recurrence-free survival between asymptomatic patients with clinical stage IA NSCLC with or without preoperative bone scan.

Trajectory patterns and cumulative burden of CEA during follow-up with non-small cell lung cancer outcomes: A retrospective longitudinal cohort study.

Previous studies of non-small cell lung cancer (NSCLC) focused on CEA measured at a single time point, ignoring serial CEA measurements. This retrospective cohort included 2959 patients underwent surgery for stage I-III NSCLC. CEA trajectory patterns and long-term cumulative CEA burden were evaluated using the latent class growth mixture model. Four CEA trajectory groups were identified, named as low-stable, decreasing, early-rising and later-rising. Compared with the low-stable group, the adjusted hazard ratios associated with death were 1.27, 4.50, and 3.68 for the other groups. Cumulative CEA burden were positively associated with the risk of death in patients not belonging to the low-stable group. The 5-year overall survival (OS) rates decreased from 62.3% to 33.0% for the first and fourth quantile groups of cumulative CEA burden. Jointly, patients with decreasing CEA trajectory could be further divided into the decreasing & low and decreasing & high group, with 5-year OS rates to be 77.9% and 47.1%. Patients with rising CEA trajectory and high cumulative CEA were found to be more likely to develop bone metastasis. Longitudinal trajectory patterns and long-term cumulative burden of CEA were independent prognostic factors of NSCLC. We recommend CEA in postoperative surveillance of NSCLC.

Bone metastases in oral squamous cell carcinoma: A real-world retrospective study based on the SEER database

BackgroundBone metastases are rare in oral squamous cell carcinoma (OSCC). It has not been defined on the risk and prognosis of OSCC patients with bone metastases. The purpose of this study was to assess the factors associated with the development and prognosis of bone metastases among OSCC patients. MethodsDemographic and clinicopathological characteristics of OSCC patients diagnosed between 2010 and 2019 was retrieved from the Surveillance, Epidemiology, and End Results (SEER) database. To explore risk factors for developing bone metastases and prognosis, the univariate and multivariate logistic and Cox regression analysis were performed, further the predictive nomogram models were constructed. ResultsThe incidence rate of bone metastases in newly diagnosed OSCC patients was 0.91 % (95 %CI 0.81% –1.02 %). Ultimately, 137 OSCC patients with bone metastases and 19,469 OSCC patients without bone metastases were included in the present study. Pathological grade, primary site, T/N stage and distant organ metastases (liver/lung/brain) were independently associated with the risk of developing bone metastases among OSCC patients. The C-index of a constructed risk-predicting nomogram was 0.86 (95 %CI 0.83–0.89). Multivariate Cox regression analysis indicated that lung metastases, the use of surgery as well as chemotherapy were three independent prognostic factors. The C-indexes of constructed risk-predicting nomograms were 0.70 (95 %CI 0.65–0.75), 0.68 (95 %CI 0.63–0.73) for OS and CSS, respectively. Calibration plots demonstrated an agreementbetween the established nomogram's predicted survival and actual survival. In addition, decision curve analysis (DCA) indicated these established nomograms had considerable net benefits and clinical utilities. ConclusionThis study defined the risk and prognostic factors for bone metastases among OSCC patients and the established nomograms were well calibrated for discrimination to predict bone metastasis development and prognosis.

Abstract 161: Aged mice decelerate bone metastasis of prostate cancer by decreasing infiltration of M2 macrophages

Abstract Bone metastasis is a major contributor to the mortality of patients with prostate cancer and results in the development of an immunosuppressive microenvironment in the bone marrow. While advanced age increases the risk of bone metastasis, effects of age-related changes on immune microenvironmental homeostasis are not yet clearly understood. To investigate interactions between cancer cells and the immune microenvironment in elderly individuals, we utilized murine-derived specific bone metastatic prostate cancer cells (RM1-BM), which we had previously isolated from bone metastatic mice and transfected with a luciferase-based reporter gene. We then injected the cells into the left ventricle of both 3‒6 months and 22‒24 months, male, wild-type mice to induce bone metastasis, using age-matched mice injected with PBS as a control. We employed in vivo imaging to compare the metastatic levels in both groups of mice every other day. On day 14, we extracted bone marrow cells for CyTOF analysis and femurs and tibias for Hematoxylin and Eosin staining. Interestingly, our preliminary results demonstrated that healthy aged mice exhibited a lower susceptibility to develop bone metastasis when compared to their younger counterparts. A further investigation of the immune subtypes revealed an increase in the percentage of macrophages in CD45+ immune cells in young mice that developed bone metastasis as opposed to age-matched controls. However, the percentage decreased in aged mice, going from 12.20% to 9.92% (p = 0.001). Lastly, macrophages were isolated from the bone marrow of 3‒6 months and 22‒24 months old mice and were co-cultured with ovalbumin-transfected RM1-BM cells (RM1-BM-ova) in vitro for 24 hours. The flow cytometry results indicated that both groups consist mainly of CD206+ (M2) macrophages. Nonetheless, those obtained from aged mice exhibited reduced ovalbumin presentation capability while maintaining a steady level of type I major histocompatibility complex (MHC-I). These findings suggested that increased infiltration of pro-inflammatory M2 macrophages within the tumor microenvironment may contribute to the bone metastasis of prostate cancer. Therefore, inhibiting M2 macrophages recruitment to the bone marrow microenvironment may prove a useful approach for treating patients with prostate cancer bone metastasis. This study was supported by the NSFC projects (81972420, 81972766, 82173336), and grants from the Shenzhen Science and Technology Innovation Commission (JCYJ20190809161811237, JCYJ20210324104214040). Citation Format: Xiao Zhang, Wei Yu, Xin Huang, Yi Lu, Jian Zhang. Aged mice decelerate bone metastasis of prostate cancer by decreasing infiltration of M2 macrophages [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 161.

Bridging the Gap in Understanding Bone Metastasis: A Multifaceted Perspective.

The treatment of patients with advanced cancer poses clinical problems due to the complications that arise as the disease progresses. Bone metastases are a common problem that cancer patients may face, and currently, there are no effective drugs to treat these individuals. Prostate, breast, and lung cancers often spread to the bone, causing significant and disabling health conditions. The bone is a highly active and dynamic tissue and is considered a favorable environment for the growth of cancer. The role of osteoblasts and osteoclasts in the process of bone remodeling and the way in which their interactions change during the progression of metastasis is critical to understanding the pathophysiology of this disease. These interactions create a self-perpetuating loop that stimulates the growth of metastatic cells in the bone. The metabolic reprogramming of both cancer cells and cells in the bone microenvironment has serious implications for the development and progression of metastasis. Insight into the process of bone remodeling and the systemic elements that regulate this process, as well as the cellular changes that occur during the progression of bone metastases, is critical to the discovery of a cure for this disease. It is crucial to explore different therapeutic options that focus specifically on malignancy in the bone microenvironment in order to effectively treat this disease. This review will focus on the bone remodeling process and the effects of metabolic disorders as well as systemic factors like hormones and cytokines on the development of bone metastases. We will also examine the various therapeutic alternatives available today and the upcoming advances in novel treatments.

Abstract A034: 3D in-vitro model picturing cancer-stromal cell crosstalk &amp; bone metastasis

Abstract Breast cancer is presently the most prevalent malignancy and the second leading cause of tumor-related deaths among women. Approximately 75% of patients with advanced breast cancer will develop bone metastasis. Despite the significant improvement in treating primary breast cancer, the 5-year survival rate for metastatic breast cancer remains at 25%. While we recognize the critical importance of cancer cells and Tumor Microenvironment (TME) communication, the field still suffers from a lack of a proper model system to reconstitute 3D multi-cellular TME in-vitro, especially for bone metastasis. Most of the current 3D in-vitro breast cancer models are composed of cancer cells only and are unable to mimic the complex cellular homeostasis within the TME. To address this deficiency along with the tumor heterogeneity, we aimed to develop a unique 3D multi-cellular culture system using patient-derived (PD) cancer cells. In this study, we implemented the “hanging drop” method to create 3D Tumor Spheroids (TSs). This method was not only sufficient to build the 3D structure, but also significantly enhanced patient-derived cancer cell line establishment rate up to 75%. 3D TSs maintained their histopathological characteristics and original hormone receptor status. Over time, TSs exhibited intratumoral hypoxia leading to significant induction of VEGF expression and EMT showcasing the quality of the system. To investigate the complex interrelation between the tumor and TME, we cultured TSs with Endothelial Cells (ECs) and pericytes to introduce the vascular component. To probe these tumor-stromal interactions, we incorporated Cancer-Associated Fibroblasts (CAFs) into TSs and observed the successful growth of Multi-Cellular Tumor Spheroids (MCTSs) alongside the tubular structure. Analysis of our data revealed that the presence of stromal cells in TME enhanced tumor survival. In this study, we define how CAFs aid in the formation of vascular structures of ECs. Recent studies also have found that the effects of CAFs are significantly high in aggressive TNBC and HER2+ cell lines compared to HR+. The long-term goal of this current study is to explore bone-mimicking nano-clay-based 3D scaffold culture systems to investigate the development of metastatic tumors and to understand the influence of bone TME on cellular responses in-vitro. Citation Format: Shrinwanti Ghosh. 3D in-vitro model picturing cancer-stromal cell crosstalk &amp; bone metastasis [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Breast Cancer Research; 2023 Oct 19-22; San Diego, California. Philadelphia (PA): AACR; Cancer Res 2024;84(3 Suppl_1):Abstract nr A034.

IL-1 Family Members in Bone Sarcomas.

IL-1 family members have multiple pleiotropic functions affecting various tissues and cells, including the regulation of the immune response, hematopoietic homeostasis, bone remodeling, neuronal physiology, and synaptic plasticity. Many of these activities are involved in various pathological processes and immunological disorders, including tumor initiation and progression. Indeed, IL-1 family members have been described to contribute to shaping the tumor microenvironment (TME), determining immune evasion and drug resistance, and to sustain tumor aggressiveness and metastasis. This review addresses the role of IL-1 family members in bone sarcomas, particularly the highly metastatic osteosarcoma (OS) and Ewing sarcoma (EWS), and discusses the IL-1-family-related mechanisms that play a role in bone metastasis development. We also consider the therapeutic implications of targeting IL-1 family members, which have been proposed as (i) relevant targets for anti-tumor and anti-metastatic drugs; (ii) immune checkpoints for immune suppression; and (iii) potential antigens for immunotherapy.

Prognostic value and relapse pattern of HER2-low in hormone receptor-positive breast cancer.

A new concept of HER2-low has emerged in recent years. However, the prognostic value and the relapse pattern of HER2-low is unclear. Our study included patients diagnosed with HER2-negative/hormone receptor-positive breast cancer to explore the differences in survival outcomes between the HER2-low group and the HER2-zero group. More importantly, we explored different recurrence patterns, including the comparison of metastatic sites and recurrence time curve between the two groups. A total of 797 patients with hormone receptor-positive breast cancer were analyzed. Similar disease-free survival (DFS) was observed between the HER2-low group and HER2-zero group (HR 0.84, 95% CI: 0.61-1.16, p = 0.290). There was also no significant difference in OS between the HER2-low group and the HER2-zero group (HR 0.77, 95% CI: 0.46-1.28, p = 0.310). When IHC 1+ and 0 were taken as a group, the IHC 2+ group had significantly better DFS than the IHC 1+ and 0 group in some subgroups. The risk of bone metastasis in patients with HER2 IHC 1+ and 0 was significantly higher than that of patients with HER2 IHC 2+ (12.7% vs. 4.7%, p < 0.001). Compared with the HER2-zero group, we found that the HER2-low group had a more obvious peak in mortality at the time of postoperative 80th-100th month. No significant difference in DFS and OS between the HER2-low group and the HER2-zero group was observed. Patients with HER2 IHC 1+ and 0 tend to develop bone metastasis. The HER2-low group had a more obvious second peak in mortality.

Automated Diagnosis of Bone Metastasis by Classifying Bone Scintigrams Using a Self-defined Deep Learning Model.

Patients with cancer can develop bone metastasis when a solid tumor invades the bone, which is the third most commonly affected site by metastatic cancer, after the lung and liver. The early detection of bone metastases is crucial for making appropriate treatment decisions and increasing survival rates. Deep learning, a mainstream branch of machine learning, has rapidly become an effective approach to analyzing medical images. To automatically diagnose bone metastasis with bone scintigraphy, in this work, we proposed to cast the bone metastasis diagnosis problem into automated image classification by developing a deep learning-based automated classification model. A self-defined convolutional neural network consisting of a feature extraction sub-network and feature classification sub-network was proposed to automatically detect lung cancer bone metastasis, with a feature extraction sub-network extracting hierarchal features from SPECT bone scintigrams and feature classification sub-network classifying high-level features into two categories (i.e., images with metastasis and without metastasis). Using clinical data of SPECT bone scintigrams, the proposed model was evaluated to examine its detection accuracy. The best performance was achieved if the two images (i.e., anterior and posterior scans) acquired from each patient were fused using pixel-wise addition operation on the bladder-excluded images, obtaining the best scores of 0.8038, 0.8051, 0.8039, 0.8039, 0.8036, and 0.8489 for accuracy, precision, recall, specificity, F-1 score, and AUC value, respectively. The proposed two-class classification network can predict whether an image contains lung cancer bone metastasis with the best performance as compared to existing classical deep learning models. The high accumulation of 99mTc MDP in the urinary bladder has a negative impact on automated diagnosis of bone metastasis. It is recommended to remove the urinary bladder before automated analysis.

Local multi-drug delivery and osteogenesis in bone metastasis of prostate cancer by a core-shell 3D printed scaffold

Prostate cancer is the most common cancer in men. Approximately 80 % of people with advanced prostate cancer reportedly develop bone metastasis. Common treatments of bone metastasis of prostate cancer (BM-PC) cause severe adverse effects. Besides, there is a high probability of metastatic bone tumor recurrence after tumor resection surgery. Thus, local drug delivery is an alternative way to prevent the difficulties as mentioned earlier. In this study, a bilayer core-shell 3D-printed scaffold was prepared. The outer layer of the scaffold serves as the drug delivery vehicle, and the internal layer creates a platform for preosteoblasts’ migration to substitute the resected tumor with healthy bone in BM-PC.First, PLGA microspheres of triptorelin (TRP-PLGA microsphere) and albumin-bound paclitaxel nanoparticles (NAB-PTX) were prepared for the assessment of their synergistic effect against DU-145 cells. To obtain the optimal combination, both microspheres and nanoparticles were loaded in the outer layer of a scaffold based on Gelatin MethAcryloyl (GelMA) hydrogel using the 3D printing method. The inner layer of the scaffold was based on GelMA and alginate containing hydroxyapatite nanoparticles (nHA). The effect of nHA in the internal layer of the scaffold was assessed through osteogenesis in vitro analyses. The 75 % inhibitory concentrations (IC75) for TRP and PTX combination were 58.75 μM and 1.94 nM, respectively, while this value was obtained at 235 μM and 39 nM for TRP and PTX, respectively, which indicates a synergistic effect and reduction in the required dose of two drugs. The outer layer of the scaffold had a mechanical strength of 25 kPa and a suitable pore size for drug delivery in 21 days. On top of that, the inner layer showed an enhanced mechanical strength of 190 kPa, which is ideal for osteogenesis. Furthermore, biodegradation of the outer layer in 3 weeks and the inner layer in 10 weeks is proportional to their objective. The presence of nHA in the internal layer of the scaffold enhanced bone regeneration (146 %), increased ALP activity (150 %), and doubled the calcium deposition within 14 days. It also led to the upregulation of RUNX2, COL1A1, and OPN genes about 86, 60, and 14 fold, respectively, within 21 days, indicating osteogenic differentiation. In conclusion, this scaffold will successfully prevent bone tumor recurrence and then enhance bone regeneration at the site.