Metastatic bone disease: Pathogenesis and therapeutic options: Up-date on bone metastasis management

Balancing Hormone Therapy: Mitigating Adverse Effects of Androgen-Deprivation Therapy and Exploring Alternatives in Prostate Cancer Management

Androgen-deprivation therapy (ADT) is well established as the standard of care in metastatic prostate cancer (PCa) management; however, ADT has significant adverse effects (AEs) that must be addressed. This review aims to highlight opportunities to mitigate AEs of ADT and explore alternatives in PCa management. Specifically, we discuss behavioral and pharmacologic strategies for mitigating ADT AEs as well as ADT-sparing approaches for hormone-sensitive and castration-resistant PCa. Equipped with effective mitigation strategies and possible alternatives, clinicians and researchers can optimize health-related quality of life for patients currently receiving ADT for PCa and consider treatments that spare patients from AEs of ADT.

Outcomes Following Pedestal Cup Reconstruction of (Impending) Pathological Fractures of the Acetabulum due to Metastatic Bone Disease

Management of periacetabular metastatic bone disease (MBD) is challenging, specifically if associated with bone loss or fracture. The aim of this study was to evaluate the complications and outcomes after undergoing peri-acetabular reconstruction using an 'ice-cream cone' pedestal cup endoprostheses for the most severe cases of (impending) pathological acetabular fractures. Fifty cases with severe periacetabular disease were identified. Acetabular defects were classified using the Metastatic Acetabular Classification (MAC). Pre- and post-operative mobility was assessed using the Eastern Cooperative Oncology Group (ECOG) Performance Status. Pain levels were assessed using a verbal rating scale. Surgical complications and patient survival were analysed; the Prognostic Immune Nutritional Index (PINI) was applied retrospectively to survival. There were 32 females and 18 males with a median age of 65 (41-88). Median post-operative follow-up was 16 months (IQR 5.5-28.5 months). Thirty-nine had complete, and 11, impending pathological fractures. The observed five-year survival was 19%, with a median survival of 16 months (IQR 5.8-42.5 months). Significantly worse survival was observed with PINI scores < 3.0 (p = 0.003). Excluding three perioperative deaths, 13 complications occurred in 12 patients: Implant failure in six patients (four aseptic loosening, one dislocation and one infection). At the final follow-up, mobility and pain levels were improved in 85% and 100%, respectively. Reconstruction of significant pelvic MBD with the 'ice-cream cone' reduces pain and improves mobility. Whilst the mortality rate is high, it remains a reasonable option for bed-bound, immobile patients. We advocate the use of an 'ice-cream cone' prosthesis for selected patients balancing the reported risks with the observed benefits.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13193-024-01917-x.

Clinical Efficacy of Percutaneous Osteoplasty Under Fluoroscopy and Cone-Beam CT Guidance for Painful Sternal Metastases: A Case Series

Background

Although percutaneous osteoplasty (POP) has been widely accepted and is now being performed for the treatment of painful bone metastases outside the spine. It is emerging as one of the most promising procedures for patients with painful bone metastasis who are unsuitable for surgery or who show resistance to radiotherapy and/or analgesic therapies. However, there are only scarce reports regarding osteoplasty in painful sternal metastases.

Subjects and Method

We report four patients with sternal metastases suffered with severe pain of anterior chest wall. The original tumors included lung cancer and thyroid cancer. For the initially pain medication failing, all the four patients received POP procedure under fluoroscopic and cone-beam CT (CBCT) guidance, and obtained satisfying resolution of painful symptoms at 6-month postop follow-up.

Conclusion

POP is a safe and effective treatment for pain caused by metastatic bone tumors in the sternum. In practice, however, percutaneous puncture of pathologic sternal fractures can be a challenge because of the long flat contour and the defacement by lytic tumor of bony landmarks. We find that the use of fluoroscopic and CBCT can facilitate POP for flat bone fractures with displacing the trajectory planning, needle advancement, and cement delivery in time.

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.

Clinical status of established MRONJ in oncology patients continuing bone-modifying agents

The continuation of bone-modifying agents (BMAs) in patients with established medication-related osteonecrosis of the jaw (MRONJ) is a common concern among dentists and oncologists. There is little evidence supporting or refuting the continued use of BMAs or drug holidays and their impact on established MRONJ. This paper evaluates the outcome of continued BMAs use on the patient's MRONJ status. A retrospective review of 29 oncology patients undergoing active cancer care for either metastatic disease or multiple myeloma was conducted. Data on demographics, oncological status, BMA history and MRONJ status were collected. In total, 90% of patients were judged to have healed or stable MRONJ while continuing BMAs. Most patients (69%) continued the same BMA regime (three- or four-weekly) that they were on before developing MRONJ. The average number of BMAs doses received after an MRONJ diagnosis was 12 (range 1-48). Three patients (10.3%) were found to have MRONJ progression, with two patients developing new sites of necrosis. This real-world dataset suggests that the majority of MRONJ cases remain stable and will not worsen with the continuation of BMAs.

Interrogating Estrogen Signaling Pathways in Human ER-Positive Breast Cancer Cells Forming Bone Metastases in Mice

Breast cancer bone metastases (BMET) are incurable, primarily osteolytic, and occur most commonly in estrogen receptor-α positive (ER+) breast cancer. ER+ human breast cancer BMET modeling in mice has demonstrated an estrogen (E2)-dependent increase in tumor-associated osteolysis and bone-resorbing osteoclasts, independent of estrogenic effects on tumor proliferation or bone turnover, suggesting a possible mechanistic link between tumoral ERα-driven osteolysis and ER+ bone progression. To explore this question, inducible secretion of the osteolytic factor, parathyroid hormone-related protein (PTHrP), was utilized as an in vitro screening bioassay to query the osteolytic potential of estrogen receptor- and signaling pathway-specific ligands in BMET-forming ER+ human breast cancer cells expressing ERα, ERß, and G protein-coupled ER. After identifying genomic ERα signaling, also responsibility for estrogen's proliferative effects, as necessary and sufficient for osteolytic PTHrP secretion, in vivo effects of a genomic-only ER agonist, estetrol (E4), on osteolytic ER+ BMET progression were examined. Surprisingly, while pharmacologic effects of E4 on estrogen-dependent tissues, including bone, were evident, E4 did not support osteolytic BMET progression (vs robust E2 effects), suggesting an important role for nongenomic ER signaling in ER+ metastatic progression at this site. Because bone effects of E4 did not completely recapitulate those of E2, the relative importance of nongenomic ER signaling in tumor vs bone cannot be ascertained here. Nonetheless, these intriguing findings suggest that targeted manipulation of estrogen signaling to mitigate ER+ metastatic progression in bone may require a nuanced approach, considering genomic and nongenomic effects of ER signaling on both sides of the tumor/bone interface.

CT-based radiomics and clinical characteristics for predicting bone metastasis in lung adenocarcinoma patients

Background

The occurrence of bone metastasis (BM) will seriously shorten the survival time of lung adenocarcinoma patients and aggravate the suffering of patients. Computed tomography (CT)-based clinical radiomics nomogram may help clinicians stratify the risk of BM in lung adenocarcinoma patients, thereby enabling personalized individualized clinical decision making.

Methods

A total of 501 patients with lung adenocarcinoma from March 2017 to March 2019 were enrolled in the study. Based on plain chest CT images, 1130 radiomics features were extracted from each lesion. One-way analysis of variance (ANOVA) and least absolute shrinkage selection operator (LASSO) algorithm were used for radiomics features selection. Univariate and multivariate analyses were used to screen for clinical characteristics and identify independent predictors of BM. Three models (radiomics model, clinical model and combined model) were constructed to predict BM in lung adenocarcinoma patients. Receiver operating characteristic (ROC) curve and decision curve analysis (DCA) were used to evaluate the performance of the three models. The DeLong test was used to compare the performance of the models.

Results

Finally, the clinical model for predicting BM in lung adenocarcinoma patients was constructed based on 5 independent predictors: cytokeratin 19-fragments (CYFRA21-1), stage, Ki-67, edge, and lobulation. The radiomics model was constructed based on 5 radiomics features. The combined model incorporating clinical independent predictors and radiomics was constructed. In the validation cohort, the area under the curve (AUC) of the clinical model, radiomics model and combined model was 0.824, 0.842 and 0.866, respectively. Delong test showed that in the training cohort, the AUC values of the radiomics model and the combined model were statistically different (P=0.03), and the AUC values of the other models were not statistically different. DCA showed that the nomogram had a highest net clinical benefit.

Conclusions

The CT-based clinical radiomics nomogram can be used as a non-invasive and quantitative method to help clinicians stratify the risk of BM in patients with lung adenocarcinoma, thereby enabling personalized clinical decision making.

A new era in the management of spinal metastasis

Despite the recent advances in cancer treatment, the incidence of patients with spinal metastases continues to grow along with the total number of cancer patients. Spinal metastases can significantly impair activities of daily living (ADL) and quality of life (QOL), compared with other types of bone metastases, as they are characterized with severe pain and paralysis caused by skeletal-related events. Reduced ADL can also lead to treatment limitations as certain anticancer agents and radiation therapy are not compatible treatments; thus, leading to a shorter life expectancy. Consequently, maintaining ADLs in patients with spinal metastases is paramount, and spine surgeons have an integral role to play in this regard. However, neurosurgeon, orthopedic and spinal surgeons in Japan do not have a proactive treatment approach to spinal metastases, which may prevent them from providing appropriate treatment when needed (clinical inertia). To overcome such endemic inertia, it is essential for 1) spine surgeons to understand and be more actively involved with patients with musculoskeletal disorders (cancer locomo) and cancer patients; 2) the adoption of a multidisciplinary approach (coordination and meetings not only with the attending oncologist but also with spine surgeons, radiologists, rehabilitation specialists, and other professionals) to preemptive treatment such as medication, radiotherapy, and surgical treatment; and 3) the integration of the latest findings associated with minimally invasive spinal treatments that have expanded the indications for treatment of spinal metastases and improved treatment outcomes. This heralds a new era in the management of spinal metastases.

Notch activation promotes bone metastasis via SPARC inhibition in adenoid cystic carcinoma

OBJECTIVES

We aimed to investigate bone metastasis induced by Notch signalling pathway dysregulation and to demonstrate that SPARC is a potential therapeutic target in adenoid cystic carcinoma (AdCC) with Notch dysregulation.

MATERIALS AND METHODS

This retrospective study enrolled 144 AdCC patients. RNA-sequencing and enrichment analyses were performed using 32 AdCC samples. Osteonectin/SPARC and the Notch activation indicator Notch intracellular domain (NICD) were detected using immunohistochemistry. Cell proliferation and migration assays were conducted using stably NICD over-expressing cells. The effect of SPARC on osteoclast differentiation in NICD cells was investigated using western blotting, quantitative reverse transcription PCR, tartrate-resistant acid phosphatase staining and resorption assays.

RESULTS

RNA-sequencing analysis showed that genes down-regulated in Notch-mutant AdCCs, such as SPARC, were enriched in ossification and osteoblast differentiation. Most (75/110, 68.2%) Notch1-wild-type AdCCs showed SPARC over-expression, whereas 30 out of 34 (88.2%) Notch1-mutant tumours showed low SPARC expression. SPARC over-expression was then found negatively to be correlated with NICD expression in 144 AdCCs. NICD over-expression promoted cell growth, migration and osteoclast differentiation, which could be partly reversed by exogenous SPARC.

CONCLUSIONS

Notch activation in AdCC contributes to bone metastasis through SPARC inhibition. The study results suggest that SPARC may represent a prognostic biomarker and potential therapeutic target.

Intra-bone marrow injection with engineered Lactococcus lactis for the treatment of metastatic tumors: Primary report

Bone marrow has the capacity to produce different types of immune cells, such as natural killer cells, macrophages, dendritic cells (DCs) and T cells. Improving the activation of immune cells in the bone marrow can enhance the therapy of bone metastases. Previously, we designed an engineered probiotic Lactococcus lactis, capable of expressing a fusion protein of Fms-like tyrosine kinase 3 ligand and co-stimulator OX40 ligand (FOLactis), and proved that it can induce the activation and differentiation of several immune cells. In this research, we successfully establish mouse models of bone metastasis, lung metastasis and intraperitoneal dissemination, and we are the first to directly inject the probiotics into the bone marrow to inhibit tumor growth. We observe that injecting FOLactis into the bone marrow of mice can better regulate the immune microenvironment of tumor-bearing mice, resulting in a tumor-suppressive effect. Compared to subcutaneous (s.c.) injection, intra-bone marrow (IBM) injection is more effective in increasing mature DCs and CD8+ T cells and prolonging the survival of tumor-bearing mice. Our results confirm that IBM injection of FOLactis reprograms the immune microenvironment of bone marrow and has remarkable effectiveness in various metastatic tumor models.

Bone marrow adipocytes and lung cancer bone metastasis: unraveling the role of adipokines in the tumor microenvironment

Bone is a common site of metastasis for lung cancer. The "seed and soil" hypothesis suggests that the bone marrow microenvironment ("soil") may provide a conducive survival environment for metastasizing tumor cells ("seeds"). The bone marrow microenvironment, comprising a complex array of cells, includes bone marrow adipocytes (BMAs), which constitute about 70% of the adult bone marrow volume and may play a significant role in tumor bone metastasis. BMAs can directly provide energy for tumor cells, promoting their proliferation and migration. Furthermore, BMAs participate in the tumor microenvironment's osteogenesis regulation, osteoclast(OC) regulation, and immune response through the secretion of adipokines, cytokines, and inflammatory factors. However, the precise mechanisms of BMAs in lung cancer bone metastasis remain largely unclear. This review primarily explores the role of BMAs and their secreted adipokines (leptin, adiponectin, Nesfatin-1, Resistin, chemerin, visfatin) in lung cancer bone metastasis, aiming to provide new insights into the mechanisms and clinical treatment of lung cancer bone metastasis.

Prevalence and Characteristics of Pathological Fractures in Patients Referred to Specialist Palliative Care: A Retrospective Study From India

Background: Prevalence of pathological fractures in palliative care is less studied. This study aimed to determine the annual prevalence of pathological fractures and describe the characteristics and treatments in patients with pathological fractures referred to a specialist palliative care clinic in a tertiary care cancer center in India. Methods: Data of adult cancer patients newly referred to the specialist palliative care clinic over 1 year with a clinico-radiological diagnosis of pathological fracture was included. Key outcomes of interest were annual prevalence, clinical characteristics, symptoms and treatments offered. Results: 75 out of 5800 (1.29%) patients newly referred to the clinic over 1 year had pathological fractures. Lung cancer was the most common primary diagnosis (n = 23).Dorsal spine (n = 25) was the most common site of fracture. Pain was the predominant symptom. Mean pain score was 7.04(SD = 1.75) and 42 patients (56%) required strong opioids for analgesia. Only 11 (16%) patients underwent surgical fixation. Median duration from diagnosis of cancer to occurrence of fracture was found to be 329 days. Treatment goals changed to best supportive care in 33 patients (44%) post fracture. Patients with bone and soft tissue neoplasms and those who received only chemotherapy previously had a higher risk of occurrence of fractures. Conclusion: Annual prevalence of pathological fractures in patients referred to the specialist palliative care clinic was 1.29%. It was associated with significant symptom burden and affected oncological treatments. Close monitoring of patients with bone metastases is crucial and proactive implementation of prophylactic measures to prevent such skeletal related events is warranted.

Single-cell Transcriptome Analysis Identifies Senescent Osteocytes as Contributors to Bone Destruction in Breast Cancer Metastasis

Breast cancer bone metastases increase fracture risk and are a major cause of morbidity and mortality among women. Upon colonization by tumor cells, the bone microenvironment undergoes profound reprogramming to support cancer progression that disrupts the balance between osteoclasts and osteoblasts, leading to bone lesions. Whether such reprogramming affects matrix-embedded osteocytes remains poorly understood. Here, we demonstrate that osteocytes in breast cancer bone metastasis develop premature senescence and a distinctive senescence-associated secretory phenotype (SASP) that favors bone destruction. Single-cell RNA sequencing identified osteocytes from mice with breast cancer bone metastasis enriched in senescence and SASP markers and pro-osteoclastogenic genes. Using multiplex in situ hybridization and AI-assisted analysis, we detected osteocytes with senescence-associated distension of satellites, telomere dysfunction, and p16Ink4a expression in mice and patients with breast cancer bone metastasis. In vitro and ex vivo organ cultures showed that breast cancer cells promote osteocyte senescence and enhance their osteoclastogenic potential. Clearance of senescent cells with senolytics suppressed bone resorption and preserved bone mass in mice with breast cancer bone metastasis. These results demonstrate that osteocytes undergo pathological reprogramming by breast cancer cells and identify osteocyte senescence as an initiating event triggering bone destruction in breast cancer metastases.

Treatment of bone metastases from solid tumors with bone-modifying agents: a web survey of Italian oncologists investigating patterns of practice drug prescription and prevention of side effects

PURPOSE

Optimal use of bone-modifying agents (BMAs) in patients with bone metastases from solid tumors is uncertain in some aspects: the drug choice; the planned treatment duration and long-term therapy; the prevention and management of possible side effects, including renal toxicity, hypocalcaemia, and medication-related osteonecrosis of the jaw (MRONJ).

METHODS

Italian oncologists were invited to fulfil a 24-question web survey about prescription of BMAs for bone metastases of breast cancer, prostate cancer, and other solid tumors. Prevention and management of side effects were also investigated.

RESULTS

Answers of 191 oncologists were collected. BMAs are usually prescribed at the time of diagnosis of bone metastases by 87.0% (breast cancer) and 76.1% (solid tumors except breast and prostate cancers) of oncologists; the decision is more articulated for prostate cancer (endocrine-sensitive versus castration-resistant). The creatinine level (32.3%), the availability of patient venous access (15.8%), and the type of primary neoplasm (13.6%) are the most reported factors involved in choice between bisphosphonates and denosumab. Zoledronic acid every 3 months was considered as a valid alternative to monthly administration by 94% of Italian oncologists. Oncologists reported a good confidence with measures aimed to prevent MRONJ, whereas uncertainness about prevention and management of hypocalcemia was registered.

CONCLUSION

Italian oncologists showed a high attitude in prescribing bisphosphonates or denosumab at the time of diagnosis of bone metastases, with a large application of preventive measures of side effects. Further studies are needed to investigate some controversial aspects, such as optimal drug treatment duration and long-term drug schedules.

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.

Synthesis, Quality Control, and Bench-to-Bed Translation of a New [68Ga]Ga-Labeled NOTA-Conjugated Bisphosphonate for Imaging Skeletal Metastases by Positron Emission Tomography

Background: Early detection of skeletal metastasis is of great interest to determine the prognosis of cancer. Positron emission tomography-computed tomography (PET-CT) imaging provides a better temporal and spectral resolution than single photon emission computed tomography-computed tomography (SPECT-CT) imaging, and hence is more suitable to detect small metastatic lesions. Although [18F]NaF has been approved by U.S. FDA for a similar purpose, requirement of a medical cyclotron for its regular formulation restricts its extensive utilization. Efforts have been made to find suitable alternative molecules that can be labeled with 68Ga and used in PET-CT imaging. Objective: The main objective of this study is to synthesize and evaluate a new [68Ga]Ga-labeled NOTA-conjugated geminal bisphosphonate for its potential use in early detection of skeletal metastases using PET-CT. Methods: The authors performed a multistep synthesis of a new NOTA-conjugated bisphosphonic acid using thiourea linker and radiolabeled the molecule with 68Ga. The radiolabeled formulation was evaluated for its in vitro stability, affinity for hydroxyapatite (HA) particles, preclinical biodistribution in animal models, and PET-CT imaging in patients. Results: The bifunctional chelator (NOTA)-conjugated bisphosphonate was synthesized with 97.8% purity and radiolabeled with 68Ga in high yield (>98%). The radiolabeled formulation was found to retain its stability in vitro to the extent of >95% up to 4 h in physiological saline and human serum. The formulation also showed high affinity for HA particles in vitro with Kd = 907 ± 14 mL/g. Preclinical biodistribution studies in normal Wistar rats demonstrated rapid and almost exclusive skeletal accumulation of the complex. PET-CT imaging in a patient confirmed its ability to detect small metastatic skeletal lesions. Conclusions: The newly synthesized [68Ga]Ga-labeled NOTA-conjugated bisphosphonate is a promising radiotracer for PET-CT imaging for skeletal metastases.

Assessment of bone turnover markers and DXA parameters to predict bone metastasis progression during zoledronate treatment: a single-center experience

Bone metastases (BM) are a serious cancer complication, potentially causing substantial morbidity. Among the clinical issues related to BM, there is the lack of specific tools for early diagnosis and prognosis. We explored whether combining bone turnover markers (BTM) with dual-energy X-ray absorptiometry (DXA) assessment could identify early BM progression and risk of skeletal-related events (SREs) during zoledronate treatment. Before the initiation of zoledronate (T0) and after six months of treatment (T1), serum levels of five BTM were measured, and patients (N = 47) underwent DXA evaluation. Standard radiological imaging was performed to assess bone tumor response to medical anti-cancer treatment. High tumor burden in bone correlated with higher serum CTX (p = 0.007) and NTX (p = 0.005) at baseline. Low concentrations of OPG at T0 predicted BM progression with a sensitivity and specificity of 63% and 77%, respectively, when a cutoff of 5.2 pmol/l was used; such a predictive meaning was stronger in patients with lytic BM (sensitivity: 88%, specificity: 80%; p = 0.0006). As for the risk of SREs, we observed an association between low baseline OC (p = 0.04) and OPG (p = 0.08) and the onset of any-time SREs, whereas an increase in OPG over time was associated with reduced risk of on-study events (p = 0.03). Moreover, a statistically significant correlation emerged between low baseline lumbar T-score and femur BMD and on-study SREs (p < 0.001 in both instances). These findings suggest that addition of DXA to BTM dosage could help stratifying the risk of SREs at the time of BM diagnosis but does not enhance our capability of detecting bone progression, during zoledronate treatment.

Nuclear medicine imaging for bone metastases assessment: what else besides bone scintigraphy in the era of personalized medicine?

Accurate detection and reliable assessment of therapeutic responses in bone metastases are imperative for guiding treatment decisions, preserving quality of life, and ultimately enhancing overall survival. Nuclear imaging has historically played a pivotal role in this realm, offering a diverse range of radiotracers and imaging modalities. While the conventional bone scan using 99mTc marked bisphosphonates has remained widely utilized, its diagnostic performance is hindered by certain limitations. Positron emission tomography, particularly when coupled with computed tomography, provides improved spatial resolution and diagnostic performance with various pathology-specific radiotracers. This review aims to evaluate the performance of different nuclear imaging modalities in clinical practice for detecting and monitoring the therapeutic responses in bone metastases of diverse origins, addressing their limitations and implications for image interpretation.

The role of secreted proteins in efferocytosis

The clearance of apoptotic cells known as efferocytosis is the final stage of apoptosis, and includes the recognition, phagocytosis, and degradation of apoptotic cells. The maintenance of tissue homeostasis requires the daily elimination of billions of apoptotic cells from the human body via the process of efferocytosis. Accordingly, aberrations in efferocytosis underlie a growing list of diseases, including atherosclerosis, cancer, and infections. During the initial phase of apoptosis, "Eat-Me" signals are exposed and recognized by phagocytes either directly through phagocyte receptors or indirectly through secreted proteins that function as bridge molecules that cross-link dying cells to phagocytes. Here, we set out to provide a comprehensive review of the molecular mechanisms and biological significance of secreted proteins in apoptotic cell clearance. Specifically, it focuses on how these secreted proteins act as bridging molecules to facilitate the clearance process.

Prediction and related genes of cancer distant metastasis based on deep learning

Cancer metastasis is one of the main causes of cancer progression and difficulty in treatment. Genes play a key role in the process of cancer metastasis, as they can influence tumor cell invasiveness, migration ability and fitness. At the same time, there is heterogeneity in the organs of cancer metastasis. Breast cancer, prostate cancer, etc. tend to metastasize in the bone. Previous studies have pointed out that the occurrence of metastasis is closely related to which tissue is transferred to and genes. In this paper, we identified genes associated with cancer metastasis to different tissues based on LASSO and Pearson correlation coefficients. In total, we identified 45 genes associated with bone metastases, 89 genes associated with lung metastases, and 86 genes associated with liver metastases. Through the expression of these genes, we propose a CNN-based model to predict the occurrence of metastasis. We call this method MDCNN, which introduces a modulation mechanism that allows the weights of convolution kernels to be adjusted at different positions and feature maps, thereby adaptively changing the convolution operation at different positions. Experiments have proved that MDCNN has achieved satisfactory prediction accuracy in bone metastasis, lung metastasis and liver metastasis, and is better than other 4 methods of the same kind. We performed enrichment analysis and immune infiltration analysis on bone metastasis-related genes, and found multiple pathways and GO terms related to bone metastasis, and found that the abundance of macrophages and monocytes was the highest in patients with bone metastasis.

Prognostic factors and real-life applicability of prognostic models for patients with bone metastases of carcinoma

OBJECTIVE

This study aimed to investigate the factors affecting the survival of patients with bone carcinoma metastases and assess the clinical applicability of existing prognostic models.

METHODS

We retrospectively evaluated 247 patients who presented to our hospital between 2011 and 2021 diagnosed with bone carcinoma metastasis. Demographic data, general health status, primary diagnoses, laboratory and radiological findings, pathological fracture status, treatment methods, and survival times of the patients were recorded, and the effects of these variables on survival time were evaluated. Previously developed Katagiri, Janssen, 2013-Spring, PathFX, and SORG prognostic models were applied, and the predictive performances of these models were evaluated by comparing the predicted survival time with the actual survival time of our patients.

RESULTS

After the multivariate analysis, the following factors were shown to be significantly associated with the survival time of patients: blood hemoglobin and leukocyte levels, lactate dehydrogenase concentration, prognostic nutritional index, body mass index, performance status, medium and fast-growing groups of primary tumors, presence of extraspinal and visceral or brain metastases, and pathological fractures. According to receiver operating characteristics and Brier scores, SORG had the overall highest performance scores, while the Janssen nomogram had the lowest.

CONCLUSION

Our report showed that all prognostic models were clinically applicable, but their performances varied. Among them, the SORG predictive model had the best performance scores overall and is the model the authors suggested for survival prediction among patients with carcinoma bone metastases.

LEVEL OF EVIDENCE

Level IV, Prognostic Study.

Cdh11: Roles in different diseases and potential value in disease diagnosis and treatment

Cadherin is a homophilic, Ca2+-dependent cell adhesion glycoprotein that mediates cell-cell adhesion. Among them, Cadherin-11 (CDH11), as a classical cadherin, participates in and influences many crucial aspects of human growth and development. Furthermore, The involvement of CDH11 has been identified in an increasing number of diseases, primarily including various tumorous diseases, fibrotic diseases, autoimmune diseases, neurodevelopmental disorders, and more. In various tumorous diseases, CDH11 acts not only as a tumor suppressor but can also promote migration and invasion of certain tumors through various mechanisms. Likewise, in non-tumorous diseases, CDH11 remains a pivotal factor in disease progression. In this context, we summarize the specific functionalities and mechanisms of CDH11 in various diseases, aiming to gain a more comprehensive understanding of the potential value of CDH11 in disease diagnosis and treatment. This endeavor seeks to provide more effective diagnostic and therapeutic strategies for clinical management across diverse diseases.

Regucalcin Is a Potential Regulator in Human Cancer: Aiming to Expand into Cancer Therapy

Regucalcin, a calcium-binding protein lacking the EF-hand motif, was initially discovered in 1978. Its name is indicative of its function in calcium signaling regulation. The rgn gene encodes for regucalcin and is situated on the X chromosome in both humans and vertebrates. Regucalcin regulates pivotal enzymes involved in signal transduction and has an inhibitory function, which includes protein kinases, protein phosphatases, cysteinyl protease, nitric oxide dynthetase, aminoacyl-transfer ribonucleic acid (tRNA) synthetase, and protein synthesis. This cytoplasmic protein is transported to the nucleus where it regulates deoxyribonucleic acid and RNA synthesis as well as gene expression. Overexpression of regucalcin inhibits proliferation in both normal and cancer cells in vitro, independent of apoptosis. During liver regeneration in vivo, endogenous regucalcin suppresses cell growth when overexpressed. Regucalcin mRNA and protein expressions are significantly downregulated in tumor tissues of patients with various types of cancers. Patients exhibiting upregulated regucalcin in tumor tissue have shown prolonged survival. The decrease of regucalcin expression is linked to the advancement of cancer. Overexpression of regucalcin carries the potential for preventing and treating carcinogenesis. Additionally, extracellular regucalcin has displayed control over various types of human cancer cells. Regucalcin may hold a prominent role as a regulatory factor in cancer development. Supplying the regucalcin gene could prove to be a valuable asset in cancer treatment. The therapeutic value of regucalcin suggests its potential significance in treating cancer patients. This review delves into the most recent research on the regulatory role of regucalcin in human cancer development, providing a novel approach for treatment.

The Pattern of Metastatic Breast Cancer: A Prospective Head-to-Head Comparison of [18F]FDG-PET/CT and CE-CT

The study aimed to compare the metastatic pattern of breast cancer and the intermodality proportion of agreement between [18F]FDG-PET/CT and CE-CT. Women with metastatic breast cancer (MBC) were enrolled prospectively and underwent a combined [18F]FDG-PET/CT and CE-CT scan to diagnose MBC. Experienced nuclear medicine and radiology physicians evaluated the scans blinded to the opposite scan results. Descriptive statistics were applied, and the intermodality proportion of agreement was used to compare [18F]FDG-PET/CT and CE-CT. In total, 76 women with verified MBC were enrolled in the study. The reported number of site-specific metastases for [18F]FDG-PET/CT vs. CE-CT was 53 (69.7%) vs. 44 (57.9%) for bone lesions, 31 (40.8%) vs. 43 (56.6%) for lung lesions, and 16 (21.1%) vs. 23 (30.3%) for liver lesions, respectively. The proportion of agreement between imaging modalities was 76.3% (95% CI 65.2-85.3) for bone lesions; 82.9% (95% CI 72.5-90.6) for liver lesions; 57.9% (95% CI 46.0-69.1) for lung lesions; and 59.2% (95% CI 47.3-70.4) for lymph nodes. In conclusion, bone and distant lymph node metastases were reported more often by [18F]FDG-PET/CT than CE-CT, while liver and lung metastases were reported more often by CE-CT than [18F]FDG-PET/CT. Agreement between scans was highest for bone and liver lesions and lowest for lymph node metastases.

Comprehensive evaluation and advanced modification of polymethylmethacrylate cement in bone tumor treatment

Bone tumors are invasive diseases with a tendency toward recurrence, disability, and high mortality rates due to their grievous complications. As a commercial polymeric biomaterial, polymethylmethacrylate (PMMA) cement possesses remarkable mechanical properties, injectability, and plasticity and is, therefore, frequently applied in bone tissue engineering. Numerous positive effects in bone tumor treatment have been demonstrated, including biomechanical stabilization, analgesic effects, and tumor recurrence prevention. However, to our knowledge, a comprehensive evaluation of the application of the PMMA cement in bone tumor treatment has not yet been reported. This review comprehensively evaluates the efficiency and complications of the PMMA cement in bone tumor treatment, for the first time, and introduces advanced modification strategies, providing an objective and reliable reference for the application of the PMMA cement in treating bone tumors. We have also summarized the current research on modifications to enhance the anti-tumor efficacy of the PMMA cement, such as drug carriers and magnetic hyperthermia.

Higher rate of progesterone receptor positivity in skeletal metastases of breast cancer with a pathological fracture vs those without fracture

Identifying risk factors for fracture occurrence in breast cancer (BC) skeletal metastases (SM) may guide the management of such bone deposits. There is sparse evidence regarding receptor status in SM and their relationship to fracture occurrence. Our study aimed to determine the relationship between estrogen (ER), progesterone (PR) and HER2 receptor status and Ki-67 index and fracture occurrence in SM of BC. Exactly 152 samples of SM of BC obtained from individual patients were evaluated. The status of the aforementioned receptors and Ki67 index were determined in SMs samples. Their expression was compared between SM that did and did not develop a fracture. Ninety-one cases sustained a pathological fracture at the SM site, and 61 did not. Patients who sustained a pathological fracture had a higher rate of PR positivity at their SMs as compared to those with no fracture. There was no significant difference between the two groups concerning ER, HER2+ or Ki67 status. SMs secondary to BC with a fracture are more likely to be PR positive than those with no fracture. Determining the receptor status in SMs may identify high-risk groups for fracture occurrence, and determining the PR status may also guide surgical and hormonal therapy.

Spatially patterned 3D model mimics key features of cancer metastasis to bone

Bone is the most common target of metastasis in breast cancer and prostate cancer, leading to significant mortality due to lack of effective treatments. The discovery of novel therapies has been hampered by a lack of physiologically relevant in vitro models that can mimic key clinical features of bone metastases. To fill this critical gap, here we report spatially patterned, tissue engineered 3D models of breast cancer and prostate cancer bone metastasis which mimic bone-specific invasion, cancer aggressiveness, cancer-induced dysregulation of bone remodeling, and in vivo drug response. We demonstrate the potential of integrating such 3D models with single-cell RNA sequencing to identify key signaling drivers of cancer metastasis to bone. Together, these results validate that spatially patterned 3D bone metastasis models mimic key clinical features of bone metastasis and can serve as a novel research tool to elucidate bone metastasis biology and expedite drug discovery.

XGBoost-based multiparameters from dual-energy computed tomography for the differentiation of multiple myeloma of the spine from vertebral osteolytic metastases

OBJECTIVES

To evaluate the performance of extreme gradient boosting (XGBoost) combined with multiparameters from dual-energy computed tomography (mpDECT) to differentiate between multiple myeloma (MM) of the spine and vertebral osteolytic metastases (VOM).

METHODS

For this retrospective study, 28 patients (83 lesions) with MM of the spine and 23 patients (54 lesions) with VOM who underwent DECT were included. The mpDECT for each lesion, including normalized effective atomic number, slope of the spectral Hounsfield unit curve, CT attenuation, and virtual noncalcium (VNCa), was obtained. Boruta was used to select the key parameters, and then subsequently merged with XGBoost to yield a prediction model. The lesions were divided into the training and testing group in a 3:1 ratio. The highest performance of the univariate analysis was compared with XGBoost using the Delong test.

RESULTS

The mpDECT of MM was significantly lower than that of VOM (all p < 0.05). In univariate analysis, VNCa had the highest area under the receiver operating characteristic curve (AUC) in the training group (0.81) and testing group (0.87). Based on Boruta, 6 parameters of DECT were selected for XGBoost model construction. The XGBoost model achieved an excellent and stable diagnostic performance, as shown in the training group (AUC of 1.0) and testing group (AUC of 0.97), with a sensitivity of 80%, a specificity of 95%, and an accuracy of 88%, which was superior to VNCa (p < 0.05).

CONCLUSIONS

XGBoost combined with mpDECT yielded promising performance in differentiating between MM of the spine and VOM.

KEY POINTS

• The multiparameters obtained from dual-energy CT of multiple myeloma differed significantly from those of vertebral osteolytic metastases. • The virtual noncalcium offered the highest AUC in the univariate analysis to distinguish multiple myeloma from vertebral osteolytic metastases. • Extreme gradient boosting combined with multiparameters from dual-energy CT had a promising performance to distinguish multiple myeloma from vertebral osteolytic metastases.

Efficacy of a HER2-Targeted Thorium-227 Conjugate in a HER2-Positive Breast Cancer Bone Metastasis Model

Human epidermal growth factor receptor 2 (HER2) is overexpressed in 15-30% of breast cancers but has low expression in normal tissue, making it attractive for targeted alpha therapy (TAT). HER2-positive breast cancer typically metastasizes to bone, resulting in incurable disease and significant morbidity and mortality. Therefore, new strategies for HER2-targeting therapy are needed. Here, we present the preclinical in vitro and in vivo characterization of the HER2-targeted thorium-227 conjugate (HER2-TTC) TAT in various HER2-positive cancer models. In vitro, HER2-TTC showed potent cytotoxicity in various HER2-expressing cancer cell lines and increased DNA double strand break formation and the induction of cell cycle arrest in BT-474 cells. In vivo, HER2-TTC demonstrated dose-dependent antitumor efficacy in subcutaneous xenograft models. Notably, HER2-TTC also inhibited intratibial tumor growth and tumor-induced abnormal bone formation in an intratibial BT-474 mouse model that mimics breast cancer metastasized to bone. Furthermore, a match in HER2 expression levels between primary breast tumor and matched bone metastases samples from breast cancer patients was observed. These results demonstrate proof-of-concept for TAT in the treatment of patients with HER2-positive breast cancer, including cases where the tumor has metastasized to bone.

Diagnostic value of whole -body diffusion weighted imaging added to bone scan in early diagnosis of bone metastases in breast cancer patients

Background

Metastases to the bones are a frequent location of metastasis in advanced breast cancer and are responsible for substantial morbidity and healthcare expenses. Imaging has been crucial in directing patient therapy for decades, contributing to the staging and response evaluation of the skeleton. This research aimed to assess the diagnostic value of whole-body magnetic resonance imaging with diffusion-weighted imaging added to radionuclide bone scans for early diagnosis of bone metastases in breast cancer patients.

Results

The study was a prospective observational cohort study performed on 20 patients with breast cancer and suspected bone metastases. The patients were evaluated first by obtaining a detailed personal history. Laboratory tests, including CBC, liver, and kidney function tests were assessed. All patients were examined by diffusion-weighted whole-body MRI (DWIBS; diffusion-weighted imaging with background body signal suppression) images and bone scintigraphy after intravenous injection of 20 mci of technetium-99m (99mTc) methylene diphosphonate using a dual head gamma camera. The total number of lesions detected by bone scan was 74, and 75 lesions were seen by DWIBS. Twenty-four lesions were missed by bone scan and detected by DWIBS. Fourteen lesions were detected by bone scan and found free by DWIBS examination in the spine and pelvic bones.

Conclusions

Whole body DWIBS seems to be a promising method of imaging in detecting bone metastases from breast cancer that could be used complementary to the traditional bone scan for more accurate diagnosis and staging of the tumor, helping to determine the most appropriate protocol of management.

Skeletal-Related Events in Renal Cell Carcinoma: Prediction With Alkaline Phosphatase (ALP), C-reactive Protein (CRP), Haemoglobin (Hb) and Erythrocyte Sedimentation Rate (ESR) (A.C.H.E.) Score for Risk Stratification

Introduction  Skeletal metastasis is catastrophic in patients with renal cell carcinoma (RCC), leading to skeletal-related events (SRE) such as nerve entrapment, hypercalcemia and even pathological fractures, which may require surgical intervention. The nature of the bone metastasis in advanced RCC is large, destructive, hyper-vascular and mostly lytic. The present retrospective analysis aims to identify potential risk factors for predicting SREs in advanced RCC with bone metastasis. Methods The clinical data of 42 patients with RCC and bone metastasis and at least one episode of SRE were reviewed, and the correlations between erythrocyte sedimentation rate (ESR), alkaline phosphatase (ALP), C-reactive protein (CRP), haemoglobin (Hb), carcinoembryonic antigen (CEA) and bone metastases were analysed. Risk factors were identified by multivariate logistic regression analysis. Bone metastasis was diagnosed on a bone scan. The receiver operating characteristic (ROC) curve calculated the cut-off value of the independent correlation factors. Results The areas under the ROC curve for ALP, Hb, CRP, and ESR were 0.84, 0.76, 0.86 and 0.88, respectively, suggesting excellent discriminatory capability of ALP, CRP, ESR and sufficient discriminative ability of Hb in predicting bone metastasis. Multivariate logistic regression analysis showed ALP, CRP, Hb and ESR associated with SRE and skeletal metastasis. Conclusion We propose that an A.C.H.E. score encompassing ALP, CRP, Hb, and ESR are potential risk factors for developing SRE and concomitant bone metastasis in advanced RCC patients. For new RCC patients, if values of ALP >128 U/L, CRP ≥74 mg/L, Hb <11.5 g/L, and ESR ≥55 mm/hr are detected, intensive monitoring and bone scanning are warranted as these cases are at a higher risk of skeletal events.

Palliative Arterial Embolization for Metastases of the Sternum

BACKGROUND

To investigate the safety and efficacy of palliative arterial embolization for metastases of the sternum.

MATERIALS AND METHODS

This study included 10 consecutive patients (5 M, 5 F; mean age 58.1; range 37-70) with metastases of the sternum from different primary tumors, treated with palliative arterial embolization using NBCA-Lipiodol between January 2007 and June 2022. Four patients received a second embolization at the same site, for a total of 14 embolizations. Data on technical and clinical success, as well as changes in tumor size, were collected. All embolization-related complications were evaluated according to the CIRSE classification system for complications.

RESULTS

Post-embolization angiography showed occlusion of more than 90% of the pathological feeding vessels in all procedures. Pain score and analgesic drug consumption were reduced by 50% in all 10 patients (100%, p < 0.05). The mean duration of pain relief was 9.5 months (range 8 to 12 months, p < 0.05). Metastatic tumor size was reduced from a mean of 71.5 cm³ (range 41.6 to 90.3 cm³) pre-embolization to a mean of 67.9 cm³ (range 38.5 to 86.1 cm³) at the 12-month follow-up (p < 0.05). None of the patients experienced embolization-related complications.

CONCLUSION

Arterial embolization is safe and effective as a palliative treatment for patients with metastases of the sternum who did not benefit from radiation therapy or experienced recurrence in symptoms.

Osteocytes: New Kids on the Block for Cancer in Bone Therapy

The tumor microenvironment plays a central role in the onset and progression of cancer in the bone. Cancer cells, either from tumors originating in the bone or from metastatic cancer cells from other body systems, are located in specialized niches where they interact with different cells of the bone marrow. These interactions transform the bone into an ideal niche for cancer cell migration, proliferation, and survival and cause an imbalance in bone homeostasis that severely affects the integrity of the skeleton. During the last decade, preclinical studies have identified new cellular mechanisms responsible for the dependency between cancer cells and bone cells. In this review, we focus on osteocytes, long-lived cells residing in the mineral matrix that have recently been identified as key players in the spread of cancer in bone. We highlight the most recent discoveries on how osteocytes support tumor growth and promote bone disease. Additionally, we discuss how the reciprocal crosstalk between osteocytes and cancer cells provides the opportunity to develop new therapeutic strategies to treat cancer in the bone.

Comparison of Percutaneous Interventional Ablation-Osteoplasty-Reinforcement-Internal Fixation (AORIF), Long Intramedullary Nailing, and Hemiarthroplasty for the Treatment of Focal Metastatic Osteolytic Lesions in the Femoral Head and Neck

PURPOSE

Osteolytic metastatic lesions in the femoral head and neck are traditionally treated with intramedullary long nailing (IM) or hemiarthroplasty (HA). Recovery, surgical complications, and medical co-morbidities delay oncologic care. This study sought to elucidate the comparative efficacy of percutaneous ablation-osteoplasty-reinforcement-internal fixation (AORIF), IM, and HA in stabilizing osteolytic lesions in the femoral head and neck.

METHODS

A retrospective study of 67 patients who underwent IM, AORIF, or HA for osteolytic femoral head and neck lesions was performed. Primary outcome was assessed using a combined pain and ambulatory score (Range 1-10: 1 = bedbound, 10 = normal ambulation) at first follow-up (~ 2 weeks). Surgical complications associated with each treatment were compared.

RESULTS

Sixty-seven patients (mean age, 65 ± 13, 36 men and 31 women) underwent IM (40), AORIF (19), and HA (8) with a mean follow-up of 9 ± 11 months. Two patients in the IM group (5%), three in the AORIF group (16%), and none in the HA (0%) group required revision procedures. AORIF demonstrated superior early improvement in combined pain and ambulatory function scores by 3.0 points [IQR = 2.0] (IM p = 0.0008, HA p = 0.0190). Odds of post-operative complications was 10.3 times higher in HA than IM (95% confidence interval 1.8 to 60.3). Future revision procedures were not found to be statistically significant between AORIF and IM (p = 0.234).

CONCLUSIONS

A minimally invasive interventional skeletal procedure for focal femoral head and neck osteolytic lesions may serve as an effective alternative treatment to traditional surgical approaches, conferring a shorter recovery time and fewer medical complications.

Bone targeted miRNA delivery system for miR-34a with enhanced anti-tumor efficacy to bone-associated metastatic breast cancer

Bone metastatic cancer is the most common occurrence in breast cancer, and the treatment is also facing great challenges. MicroRNA-34a (miRNA-34a) is a promising anti-cancer miRNA for gene therapy to bone metastatic cancer patients. However, the lack of specificity to bone and low accumulation at the site of bone tumor remains the major challenge when used bone-associated tumor. To solve this problem, a bone-targeted vector for delivery of miR-34a to bone metastatic breast cancer was constructed by using the commonly used gene vector branched polyethylenimine 25 k (BPEI 25 k) as the skeleton and linking with alendronate (ALN) moieties for bone targeting group. The constructed gene delivery system PCA/miR-34a can efficiently prevent miR-34a from degradation during blood circulation and enhance the specific bone delivery and distribution. PCA/miR-34a nanoparticles can be uptake into tumor cells through clathrin and caveolae-mediated endocytosis, and directly regulate the expression of oncogenes, thus promoting tumor cell apoptosis and relieving bone tissue erosion. The results of experiments in vitro and in vivo confirmed that the constructed bone-targeted miRNA delivery system PCA/miR-34a can enhance the anti-tumor efficacy in bone metastatic cancer, and provide a potential strategy for gene therapy in bone metastatic cancer.

PECAM1 plays a role in the pathogenesis and treatment of bone metastases

Bone is the third most common metastatic site for all primary tumors, the common primary focus of bone metastases include breast cancer, prostate cancer, and so on. And the median survival time of patients with bone metastases is only 2–3 years. Therefore, it is urgent to develop new targets to diagnose and treat bone metastases. Based on two data sets GSE146661 and GSE77930 associated with bone metastases, it was found that 209 genes differentially expressed in bone metastases group and control group. PECAM1 was selected as hub-gene for the follow-up research after constructing protein-protein interaction (PPI) network and enrichment analysis. Moreover, q-PCR analysis verified that the expression of PECAM1 decreased in bone metastatic tumor tissues. PECAM1 was believed to be possibly related to the function of osteoclasts, we knocked down the expression of PECAM1 with shRNA in lymphocytes extracted from bone marrow nailed blood. The results indicated that sh-PECAM1 treatment could promote osteoclast differentiation, and the sh-PECAM1-treated osteoclast culture medium could significantly promote the proliferation and migration of tumor cells. These results suggested that PECAM1 may be a potential biomarker for the diagnosis and treatment of bone metastases of tumor.

Genistein and coumestrol reduce MCF-7 breast cancer cell viability and inhibit markers of preferential metastasis, bone matrix attachment and tumor-induced osteoclastogenesis

The propensity of breast cancer to preferentially metastasize to the skeleton is well known. Once established in bone metastatic breast cancers have a poor prognosis due to their ability to promote extensive bone loss which augments tumor burden. Unfortunately, current anti-resorptive therapies for skeletal metastasis are typically prescribed after secondary tumors have formed and are palliative in nature. One group of compounds with the potential to reduce both tumor burden and osteolysis are phytoestrogens (PE), but the mechanisms mediating a beneficial effect are unclear. Therefore, the current study examined the effect of genistein and coumestrol alone or in combination on breast cancer cell number, expression of mediators of preferential skeletal metastasis, bone matrix attachment and tumor-induced osteoclast formation. Results showed that genistein and coumestrol significantly reduced viable cell number in an estrogen receptor dependent manner (p < 0.05), whereas combinations of PE had no effect. In addition, genistein and coumestrol significantly reduced expression of genes driving epithelial to mesenchymal transition (snail), bone attachment (CXCR4 and integrin αV) and osteolysis (PTHrP and TNF-α). In keeping with this genistein and coumestrol significantly suppressed attachment of breast cancer cells to bone matrix and inhibited tumor and RANKL-induced osteoclast formation. Our data suggests that phytoestrogens not only decrease breast cancer cell viability but also antagonize essential tumor bone interactions that establish and drive the progression of skeletal metastasis.

The inflammatory macrophages repress the growth of bone metastatic human prostate cancer cells via TNF-α and IL-6 signaling: Involvement of cell signaling regulator regucalcin

Macrophages in the cancer microenvironments may play a regulatory role in the progression and metastasis of prostate cancer cells. However, the crosstalk between macrophages and prostate cancer cells is poorly understood. This study elucidates whether inflammatory macrophages regulate the proliferation and death of human prostate cancer cells in vitro. The RAW264.7 mouse macrophages were cocultured with PC-3 or DU-145 wild-type cells by using a Transwell chamber in vitro. RAW264.7 cells were cocultured with PC-3 or DU-145 cells in the presence of lipopolysaccharide (LPS). This coculturing blocked the proliferation and accelerated the death of cancer cells. Interestingly, cancer cell proliferation was repressed and death was promoted by the addition of the conditioned medium obtained from RAW264.7 cells treated with LPS. Culturing with LPS mostly augmented the production of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in the culture medium of RAW264.7 cells. The effects of the conditioned medium on the proliferation and death of PC-3 or DU-145 cells were blocked by NF-κB or STAT3 signaling inhibitors. Moreover, the effects of the conditioned medium on the proliferation and death of prostate cancer cells were not expressed in regucalcin-overexpressing cancer cells that diminish the levels of NF-κB p65 and STAT3. Culturing with extracellular TNF-α, IL-6, or regucalcin triggered inhibition of the proliferation of PC-3 wild-type cells. The levels of regucalcin in PC-3 cells were elevated by TNF-α or IL-6 stimulation. This study demonstrates that inflammatory macrophages triggered the loss of prostate cancer cells via the signaling process of NF-κB, STAT3, or regucalcin.

Bone Metastases and Health in Prostate Cancer: From Pathophysiology to Clinical Implications

Clinically relevant bone metastases are a major cause of morbidity and mortality for prostate cancer patients. Distinct phenotypes are described: osteoblastic, the more common osteolytic and mixed. A molecular classification has been also proposed. Bone metastases start with the tropism of cancer cells to the bone through different multi-step tumor-host interactions, as described by the "metastatic cascade" model. Understanding these mechanisms, although far from being fully elucidated, could offer several potential targets for prevention and therapy. Moreover, the prognosis of patients is markedly influenced by skeletal-related events. They can be correlated not only with bone metastases, but also with "bad" bone health. There is a close correlation between osteoporosis-a skeletal disorder with decreased bone mass and qualitative alterations-and prostate cancer, in particular when treated with androgen deprivation therapy, a milestone in its treatment. Systemic treatments for prostate cancer, especially with the newest options, have improved the survival and quality of life of patients with respect to skeletal-related events; however, all patients should be evaluated for "bone health" and osteoporotic risk, both in the presence and in the absence of bone metastases. Treatment with bone-targeted therapies should be evaluated even in the absence of bone metastases, as described in special guidelines and according to a multidisciplinary evaluation.

Adjuvant treatment of surgically treated bone metastasis patients: association with hospital characteristics and trends over time

Patients with metastatic disease of the bone (MDB) often require surgical stabilization; however, there is not widespread consensus on subsequent adjuvant management. This study aimed to characterize utilization of perioperative adjuvant treatment among MDB patients. We identified 9413 surgically treated MDB patients with primary (breast, kidney, lung, prostate, or multiple myeloma) cancer from Surveillance, Epidemiology, and End Results (SEER)-Medicare data. Logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (CI) for receipt of chemotherapy, radiation, and bisphosphonates, respectively, in the adjuvant setting (90 days before or after surgery) by hospital characteristics-medical school affiliation, surgery volume, and Commission on Cancer (CoC) accreditation. Trends in treatment utilization by year of surgery were assessed via bar charts and Chi-square tests for trend. Patients surgically treated at major medical schools or high-volume facilities (compared to no medical school affiliation and low volume) had significantly higher odds of receiving radiation and chemotherapy, independent of patient and tumor characteristics (OR (95% CI); medical school: radiation 1.33 (1.19-1.49), chemotherapy 1.15 (1.02-1.30); and high volume: radiation 1.22 (1.11-1.34), chemotherapy 1.11 (1.02-1.22)). Patients surgically treated at CoC-accredited institutions, compared to non-accredited, had significantly higher odds of receiving radiation and bisphosphonates [radiation 1.24 (1.13-1.36); bisphosphonates 1.15 (1.04-1.28)]. Use of chemotherapy and bisphosphonates increased while radiation use declined over the study period from 1991 to 2014. Medical school affiliation, hospital volume, and CoC accreditation are associated with receipt of adjuvant treatment to prevent or manage pathologic fractures in MDB patients. Further investigation is needed to determine whether these associations reflect delivery of optimal care.

The Superiority of Fibroblast Activation Protein Inhibitor (FAPI) PET/CT Versus FDG PET/CT in the Diagnosis of Various Malignancies

Cancer represents a major cause of death worldwide and is characterized by the uncontrolled proliferation of abnormal cells that escape immune regulation. It is now understood that cancer-associated fibroblasts (CAFs), which express specific fibroblast activation protein (FAP), are critical participants in tumor development and metastasis. Researchers have developed various FAP-targeted probes for imaging of different tumors from antibodies to boronic acid-based inhibitor molecules and determined that quinoline-based FAP inhibitors (FAPIs) are the most appropriate candidate as the radiopharmaceutical for FAPI PET/CT imaging. When applied clinically, FAPI PET/CT yielded satisfactory results. Over the past few years, the utility and effectiveness of tumor detection and staging of FAPI PET/CT have been compared with FDG PET/CT in various aspects, including standardized uptake values (SUVs), rate of absorbance and clearance. This review summarizes the development and clinical application of FAPI PET/CT, emphasizing the diagnosis and management of various tumor types and the future prospects of FAPI imaging.

Development and validation of nomograms to predict early death for elderly lung cancer patients

Background

Due to the aging of society, the average age of LC (lung cancer) patients has increased in recent years. The purpose of this study was to determine the risk factors and develop nomograms to predict the probability of early death (dead in three months) for elderly (≥ 75 years old) LC patients.

Methods

Data of elderly LC patients were obtained from the SEER database by using the SEER stat software. All patients were randomly divided into a training cohort and a validation cohort in a ratio of 7:3. The risk factors of all-cause early and cancer-specific early death were identified by univariate logistic regression and backward stepwise multivariable logistic regression in the training cohort. Then, risk factors were used to construct nomograms. The performance of nomograms was validated by receiver operating curves (ROC), calibration curves, and decision curve analysis (DCA) in the training cohort and validation cohort.

Results

A total of 15,057 elderly LC patients in the SEER database were included in this research and randomly divided into a training cohort (n = 10,541) and a validation cohort (n = 4516). The multivariable logistic regression models found that there were 12 independent risk factors for the all-cause early death and 11 independent risk factors for the cancer-specific early death of the elderly LC patients, which were then integrated into the nomograms. The ROC indicated that the nomograms exhibited high discriminative ability in predicting all-cause early (AUC in training cohort = 0.817, AUC in validation cohort = 0.821) and cancer-specific early death (AUC in training cohort = 0.824, AUC in validation cohort = 0.827). The calibration plots of the nomograms were close to the diagonal line revealing that there was good concordance between the predicted and practical early death probability in the training and validation cohort. Moreover, the results of DCA analysis indicated that the nomograms had good clinical utility in predicting early death probability.

Conclusion

The nomograms were constructed and validated to predict the early death probability of elderly LC patients based on the SEER database. The nomograms were expected to have high predictive ability and good clinical utility, which may help oncologists develop better treatment strategies.

Predictive models for the risk and prognosis of bone metastasis in patients with newly-diagnosed esophageal cancer: A retrospective cohort study

Background

Esophageal cancer (EC) is a common malignant tumor worldwide, and patients with both EC and bone metastasis (BM) have a poor prognosis. We aimed to determine the risk and prognostic factors for BM in patients with newly diagnosed EC and to conduct two nomograms to predict the probability of BM and overall survival after BM.

Methods

Data from patients with EC from 2010 to 2015 were reviewed in the Surveillance, Epidemiology, and End Results (SEER) database. We divided participants into training and validation cohorts using univariate and multivariate logistic regression analyses and Cox regression models to explore the risk and prognostic factors of BM, respectively. Moreover, two nomograms were developed for predicting the risk and prognosis of BM in patients with EC. Then we used receiver operating characteristic curves, decision curve analysis, and calibration curves to evaluate the nomogram models. The overall survival of patients with EC and BM was analyzed using the Kaplan-Meier method.

Results

A total of 10,730 patients with EC were involved, 735 of whom had BM at the time of diagnosis. Histologic type, sex, age, N stage, primary site, liver, lung, and brain metastases, and tumor differentiation grade were identified as independent BM risk factors. Histological type, chemotherapy, brain, liver, and lung metastases were identified as prognostic risk factors for patients with EC and BM. We developed diagnostic and prognostic nomograms according to the results. Receiver operating characteristic curves, calibration, and Kaplan-Meier curves, and decision curve analysis all indicated that both nomograms had great clinical predictive ability and good clinical application potential.

Conclusions

Two novel nomograms were constructed to predict the risk and prognosis of BM in patients with EC. These prediction models can effectively assist clinicians in clinical decision-making based on their good accuracy and reliability.

The road of NSCLC stem cells toward bone metastases

Despite advancement in therapeutic options, Non-Small Cell lung cancer (NSCLC) remains a lethal disease mostly due to late diagnosis at metastatic phase and drug resistance. Bone is one of the more frequent sites for NSCLC metastatization. A defined subset of cancer stem cells (CSCs) that possess motile properties, mesenchymal features and tumor initiation potential are defined as metastasis initiating cells (MICs). A better understanding of the mechanisms supporting MIC dissemination and interaction with bone microenvironment is fundamental to design novel rational therapeutic option for long lasting efficient treatment of NSCLC. In this review we will summarize findings about bone metastatic process initiated by NSCLC MICs. We will review how MICs can reach bone and interact with its microenvironment that supports their extravasation, seeding, dormancy/proliferation. The role of different cell types inside the bone metastatic niche, such as endothelial cells, bone cells, hematopoietic stem cells and immune cells will be discussed in regards of their impact in dictating the success of metastasis establishment by MICs. Finally, novel therapeutic options to target NSCLC MIC-induced bone metastases, increasing the survival of patients, will be presented.

Risk Factors, Patterns, and Distribution of Bone Metastases and Skeletal-Related Events in High-Risk Breast Cancer Patients

BACKGROUND

More than a quarter of breast cancer patients are at risk to develop recurrent metastases to the bone.

OBJECTIVE

This study was designed to identify risk factors and predilections of bone metastasis and skeletal-related events (SRE) in a population of breast cancer survivors initially diagnosed in advanced stages and with high-risks of relapse.

METHODS

Associated risk factors, distribution, and attainable treatment of bone metastasis and SRE were analyzed in a cohort of 1,329 breast cancer patients. The association with dependent variables was subsequently analyzed using multivariable logistic regression. Sociodemographic and adverse clinical characteristics were included as covariates of progression into bone metastasis and SREs.

RESULTS

Of 1329 breast cancer patients, 246 patients (18.5%) were diagnosed as metastatic breast cancer in which 232 of them (94.3%) had bone metastases. Spines were the most common sites of bone metastases (25.6%). In multivariable analysis, advanced stage at diagnosis (OR=1.840, 95%CI:1.198-2.826, P=0.005), luminal subtype (OR=1.788, 95%CI:1.206-2.652, P=0.045), lobular histology (OR=1.795, 95%CI:1.012-3/184, P=0.046), positive axillary lymph node (OR=1.771, 95%CI:1.087-2.886, P=0.022), multiple metabolic comorbidities (OR=2.193, 95%CI:1.371-3.508, P=0.001), early menopause (OR=2.136, 95%CI:1.116-4.464, P=0.046) were significantly associated with risk of recurrent bone metastases. SREs occurred in 89 (68.5%) patients. Several risk factors for SREs were early menopausal age (OR=2.342, P=0.024), advanced stages (OR=1.404, P=0.039), lobular histology (OR=2.279, P=0.007), and having multiple metabolic comorbidities (OR=1.728, P=0.039).

CONCLUSION

Bone metastases and SREs are relatively high in breast cancer patients diagnosed in advanced stages. Luminal subtypes, having multiple metabolic comorbidities, and lobular histology are associated with higher risks of recurrent bone metastases. Living in rural areas and advanced stage at diagnosis as a risk factors for bone metastases might represent a social gradient of care delivery.

Improving Bone Health in Patients with Metastatic Prostate Cancer with the Use of Algorithm-Based Clinical Practice Tool

Background: The bone health of patients with locally advanced and metastatic prostate cancer is at risk from treatment-related bone density loss and skeletal-related events from metastatic disease in bones. Evidence-based guidelines recommend using denosumab or zoledronic acid at bone metastasis-indicated dosages in the setting of castration-resistant prostate cancer with bone metastases and at the osteoporosis-indicated dosages in the hormone-sensitive setting in patients with a significant risk of fragility fracture. For the concerns of jaw osteonecrosis, a dental evaluation is recommended before starting bone-modifying agents. The literature review suggests a limited evidence-based practice for bone health with prostate cancer in the real world. Both under-treatment and inappropriate dosing of bone remodeling therapies place additional risks to bone health. An incomplete dental work up before starting bone-modifying agents increases the risk of jaw osteonecrosis. Methods: We created an algorithm-based clinical practice tool to minimize the deviation from evidence-based guidelines at our center and provide appropriate bone health care to our patients by ensuring indication-appropriate dosing and dental screening rates. This order set was incorporated into the electronic medical record system for ordering a bone remodeling agent for prostate cancer. The tool prompts the clinicians to follow the appropriate algorithm in a stepwise manner to ensure a pretreatment dental evaluation and use of the correct dosage of drugs. Results: We analyzed the data from Sept 2019 to April 2022 following the incorporation of this tool. 0/35 (0%) patients were placed on inappropriate bone modifying agent dosing, and dental health was addressed in every patient before initiating treatment. We compared the change in the practice of prescribing and noted a significant difference in the clinician’s practice while prescribing denosumab/zoledronic acid before and after implementation of this tool [incorrect dosing: 24/41 vs. 0/35 (p < 0.00001)]; and an improvement in pretreatment dental checkup before and after implementation of the tool was noted to be [missed dental evaluation:12/41 vs. 0/35 (p < 0.00001)]. Conclusion: We found that incorporating an evidence-based algorithm in the order set while prescribing bone remodeling agents significantly improved our institutional clinical practice of indication-appropriate dosing and dental screening rates, and facilitated high-quality, evidence-based care to our patients with prostate cancer.

Deep learning-based algorithm improved radiologists' performance in bone metastases detection on CT

OBJECTIVES

To develop and evaluate a deep learning-based algorithm (DLA) for automatic detection of bone metastases on CT.

METHODS

This retrospective study included CT scans acquired at a single institution between 2009 and 2019. Positive scans with bone metastases and negative scans without bone metastasis were collected to train the DLA. Another 50 positive and 50 negative scans were collected separately from the training dataset and were divided into validation and test datasets at a 2:3 ratio. The clinical efficacy of the DLA was evaluated in an observer study with board-certified radiologists. Jackknife alternative free-response receiver operating characteristic analysis was used to evaluate observer performance.

RESULTS

A total of 269 positive scans including 1375 bone metastases and 463 negative scans were collected for the training dataset. The number of lesions identified in the validation and test datasets was 49 and 75, respectively. The DLA achieved a sensitivity of 89.8% (44 of 49) with 0.775 false positives per case for the validation dataset and 82.7% (62 of 75) with 0.617 false positives per case for the test dataset. With the DLA, the overall performance of nine radiologists with reference to the weighted alternative free-response receiver operating characteristic figure of merit improved from 0.746 to 0.899 (p < .001). Furthermore, the mean interpretation time per case decreased from 168 to 85 s (p = .004).

CONCLUSION

With the aid of the algorithm, the overall performance of radiologists in bone metastases detection improved, and the interpretation time decreased at the same time.

KEY POINTS

• A deep learning-based algorithm for automatic detection of bone metastases on CT was developed. • In the observer study, overall performance of radiologists in bone metastases detection improved significantly with the aid of the algorithm. • Radiologists' interpretation time decreased at the same time.

Biological and Clinical Aspects of Metastatic Spinal Tumors

Simple Summary

Spine metastases are a common life-threatening complication of advanced-stage malignancies and often result in poor prognosis. Symptomatic spine metastases develop in the course of about 10% of malignant neoplasms. Therefore, it is essential for contemporary medicine to understand metastatic processes in order to find appropriate, targeted therapeutic options. Our literature review aimed to describe the up-to-date knowledge about the molecular pathways and biomarkers engaged in the spine’s metastatic processes. Moreover, we described current data regarding bone-targeted treatment, the emerging targeted therapies, radiotherapy, and immunotherapy used for the treatment of spine metastases. We hope that knowledge comprehensively presented in our review will contribute to the development of novel drugs targeting specific biomarkers and pathways. The more we learn about the molecular aspects of cancer metastasis, the easier it will be to look for treatment methods that will allow us to precisely kill tumor cells.

Abstract

Spine metastases are a common life-threatening complication of advanced-stage malignancies and often result in poor prognosis. Symptomatic spine metastases develop in the course of about 10% of malignant neoplasms. Therefore, it is essential for contemporary medicine to understand metastatic processes in order to find appropriate, targeted therapeutic options. Thanks to continuous research, there appears more and more detailed knowledge about cancer and metastasis, but these transformations are extremely complicated, e.g., due to the complexity of reactions, the variety of places where they occur, or the participation of both tumor cells and host cells in these transitions. The right target points in tumor metastasis mechanisms are still being researched; that will help us in the proper diagnosis as well as in finding the right treatment. In this literature review, we described the current knowledge about the molecular pathways and biomarkers engaged in metastatic processes involving the spine. We also presented a current bone-targeted treatment for spine metastases and the emerging therapies targeting the discussed molecular mechanisms.

Characteristics and survival in bone metastatic breast cancer patients with different hormone receptor status: A population-based cohort study

Background

Accumulating preclinical evidence has uncovered the indispensable role of steroid hormone and their receptors, namely, estrogen receptor (ER) and progesterone receptor (PR), in the development of bone metastases in breast cancer. Limited data are available regarding the survival difference between different hormone receptor (HR) subgroups, and its prognostic significance is uncertain now. Such data are important for risk stratification and needed to formulate specialized regimen for bone metastatic breast cancer.

Methods

From the year of diagnosis 2010 to 2018, 554,585 breast cancer patients, among which are 19,439 with bone metastasis and 10,447 with bone-only metastasis, were extracted from the Surveillance, Epidemiology, and End Results (SEER) database. Kaplan–Meier survival analysis was performed to compare the survival difference between the different HR status subgroups. Univariate and multivariate Cox proportional hazard regression was used to validate the prognostic role of HR status and identify other prognostic factors in bone metastatic breast cancer.

Results

ER-positive/PR-positive breast cancer patients with bone metastasis showed the best breast cancer-specific survival (BCSS) and overall survival (OS) than those with other HR statuses, while single PR-positive bone metastatic breast cancers manifest similar survival with ER-negative/PR-negative ones. Adjusted Cox regression analysis demonstrated that patients with older age, male, black race, ILC, higher tumor grade, T3–T4, HER2-negative status, absence of surgery or adjuvant treatment, and HR status other than ER-positive/PR-positive tended to have worse outcomes. Further subgroup analysis based on HER2 status showed that within HER2-positive breast cancers, ER-positive/PR-positive ones still manifest better survival than the other three HR status subgroups, which are similar in survival outcomes.

Conclusion

Although collectively viewed as HR-positive breast cancers, certain distinctions exist between bone metastatic breast cancers with different HR statuses in survival outcome. Our findings indicate that despite metastasizing to the same location, the different survival rate is determined by the HR status of breast cancer. The selection and intensity of the regimen should consider HR status, and HER2 status occasionally, when treating bone metastatic breast cancer.

Functional and Survival Outcomes of Patients following the Harrington Procedure for Complex Acetabular Metastatic Lesions

Background: The Harrington surgical technique makes it possible to manage complex, extensive bone lesions using pins and cement to consolidate bone for acetabular cup positioning. However, it may be associated with a high reoperation rate, and the functional results of this surgery are not precisely described in the literature. Methods: In a monocentric retrospective study including all patients operated on using the Harrington procedure associated with THA between 2005 and 2020, we aimed to assess preoperative and postoperative function, reoperation-free survival, and overall survival. Results: Functional improvement was significant for Parker scores (preoperative: 3.6 ± 2.0; 6-month follow-up: 6.6 ± 3.2; 12-month follow-up: 7.6 ± 2.1) and Musculoskeletal Tumor Society (MSTS) scores (preoperative: 31.1 ± 16.2%; 6-month follow-up: 67.7 ± 30.6%; 12-month follow-up: 82.4 ± 24.0%). Of the 21 patients included, the reoperation-free survival rate was 76.1% [CI 95%: 58.1–99.7] at six and twelve months, with the main complications being pin migration (50.0%) and infection (25%). The patient overall survival rate was 76.2% [95% CI: 59.9–96.7] at six months and 61.9% [95% CI: 59.9–96.7] at 12 months. Discussion: These results underlined significant functional improvements following a conventional Harrington procedure, with acceptable reoperation rates.