Management of bone metastases in cancer: a review

Artificial intelligence in skeletal metastasis imaging

In the field of metastatic skeletal oncology imaging, the role of artificial intelligence (AI) is becoming more prominent. Bone metastasis typically indicates the terminal stage of various malignant neoplasms. Once identified, it necessitates a comprehensive revision of the initial treatment regime, and palliative care is often the only resort. Given the gravity of the condition, the diagnosis of bone metastasis should be approached with utmost caution. AI techniques are being evaluated for their efficacy in a range of tasks within medical imaging, including object detection, disease classification, region segmentation, and prognosis prediction in medical imaging. These methods offer a standardized solution to the frequently subjective challenge of image interpretation.This subjectivity is most desirable in bone metastasis imaging. This review describes the basic imaging modalities of bone metastasis imaging, along with the recent developments and current applications of AI in the respective imaging studies. These concrete examples emphasize the importance of using computer-aided systems in the clinical setting. The review culminates with an examination of the current limitations and prospects of AI in the realm of bone metastasis imaging. To establish the credibility of AI in this domain, further research efforts are required to enhance the reproducibility and attain robust level of empirical support.

Update on musculoskeletal applications of magnetic resonance-guided focused ultrasound

Magnetic resonance-guided focused ultrasound (MRgFUS) is a noninvasive, incisionless, radiation-free technology used to ablate tissue deep within the body. This technique has gained increased popularity following FDA approval for treatment of pain related to bone metastases and limited approval for treatment of osteoid osteoma. MRgFUS delivers superior visualization of soft tissue targets in unlimited imaging planes and precision in targeting and delivery of thermal dose which is all provided during real-time monitoring using MR thermometry. This paper provides an overview of the common musculoskeletal applications of MRgFUS along with updates on clinical outcomes and discussion of future applications.

Factors associated with skeletal-related events in patients with bone metastatic melanoma: A retrospective study of 481 patients

OBJECTIVES

Metastatic bone disease is estimated to develop in up to 17% of patients with melanoma, compromising skeleton integrity resulting in skeletal-related events (SREs), which impair quality of life and reduce survival. The objective of the study was to investigate (1) the proportion of melanoma patients developing SREs following diagnosis of bone metastasis and (2) the predictors for SREs in this patient cohort.

METHODS

Four hundred and eighty-one patients with bone metastatic melanoma from two tertiary centers in the United States from 2008 to 2018 were included. The primary outcome was 90-day and 1-year occurrence of a SRE, including pathological fractures of bones, cord compression, hypercalcemia, radiotherapy, and surgery. Fine-Gray regression analysis was performed for overall SREs and pathological fracture, with death as a competing risk.

RESULTS

By 1-year, 52% (258/481) of patients experienced SREs, and 28% (137/481) had a pathological fracture. At 90-day, lytic lesions, bone pain, elevated calcium and absolute lymphocyte, and decreased albumin and hemoglobin were associated with higher SRE risk. The same factors, except for decreased hemoglobin, were shown to predict development of SREs at 1-year.

CONCLUSION

The high incidence of SREs and pathological fractures warrants vigilance using the identified factors in this study and preventative measures during clinical oncological care.

A systematic review of deep learning-based spinal bone lesion detection in medical images

Spinal bone lesions encompass a wide array of pathologies, spanning from benign abnormalities to aggressive malignancies, such as diffusely localized metastases. Early detection and accurate differentiation of the underlying diseases is crucial for every patient's clinical treatment and outcome, with radiological imaging being a core element in the diagnostic pathway. Across numerous pathologies and imaging techniques, deep learning (DL) models are progressively considered a valuable resource in the clinical setting. This review describes not only the diagnostic performance of these models and the differing approaches in the field of spinal bone malignancy recognition, but also the lack of standardized methodology and reporting that we believe is currently hampering this newly founded area of research. In line with their established and reliable role in lesion detection, this publication focuses on both computed tomography and magnetic resonance imaging, as well as various derivative modalities (i.e. SPECT). After conducting a systematic literature search and subsequent analysis for applicability and quality using a modified QUADAS-2 scoring system, we confirmed that most of the 14 identified studies were plagued by major limitations, such as insufficient reporting of model statistics and data acquisition, a lacking external validation dataset, and potentially biased annotation. Although we experienced these limitations, we nonetheless conclude that the potential of these methods shines through in the presented results. These findings underline the need for more stringent quality controls in DL studies, as well as model development to afford increased insight and progress in this promising novel field.

Response rate specific to bone metastasis of various cancers for immune checkpoint inhibitors: a systematic review

PURPOSE

Immune checkpoint inhibitors (ICIs) have improved the prognosis of patients with cancer, such as melanoma, renal cell carcinoma, head and neck cancer, non-small cell lung cancer (NSCLC), and urothelial carcinoma. The extension of life expectancy has led to an increased incidence of bone metastases (BM) among patients with cancer. BM result in skeletal-related events, including severe pain, pathological fractures, and nerve palsy. Surgery is typically required for the treatment of BM in patients with an impending fracture; however, it may be avoided in those who respond to ICIs. We systematically reviewed studies analyzing BM responses to treatment with ICIs.

METHODS

This study was conducted in accordance with the recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-analyses 2020 statement and registered in the UMIN Clinical Trials Registry (ID: UMIN000053707). Studies reporting response rates based on the Response Evaluation Criteria in Solid Tumors (RECIST) or the MD Anderson Cancer Center (MDA) criteria specific for BM in patients treated with ICIs were included; reports of fewer than five cases and review articles were excluded. Studies involving humans, published in English and Japanese, were searched. The PubMed, Embase, and the Cochrane Central Register of Controlled Trials (CENTRAL) databases were searched. Ultimately, nine studies were analyzed. The Risk of Bias Assessment tool for Non-randomized Studies was used to assess the quality of studies.

RESULTS

Based on the MDA criteria, complete response (CR) or partial response (PR) was observed in 44-78% and 62% patients treated with ICIs plus denosumab for NSCLC and melanoma, respectively. According to the RECIST, CR or PR was recorded in 5% and 7-28% of patients treated with ICIs for renal cell carcinoma and urothelial carcinoma, respectively.

CONCLUSION

Although response rates to ICIs for BM are poor, patients treated with ICI plus denosumab for bone metastases with impending fractures from NSCLC and melanoma are likely to avoid surgery to prevent fractures.

A New Deep Learning Algorithm for Detecting Spinal Metastases on Computed Tomography Images

STUDY DESIGN

Retrospective diagnostic study.

OBJECTIVE

To automatically detect osteolytic bone metastasis lesions in the thoracolumbar region using conventional computed tomography (CT) scans, we developed a new deep learning (DL)-based computer-aided detection model.

SUMMARY OF BACKGROUND DATA

Radiographic detection of bone metastasis is often difficult, even for orthopedic surgeons and diagnostic radiologists, with a consequent risk for pathologic fracture or spinal cord injury. If we can improve detection rates, we will be able to prevent the deterioration of patients' quality of life at the end stage of cancer.

MATERIALS AND METHODS

This study included CT scans acquired at Tokyo Medical and Dental University (TMDU) Hospital between 2016 and 2022. A total of 263 positive CT scans that included at least one osteolytic bone metastasis lesion in the thoracolumbar spine and 172 negative CT scans without bone metastasis were collected for the datasets to train and validate the DL algorithm. As a test data set, 20 positive and 20 negative CT scans were separately collected from the training and validation datasets. To evaluate the performance of the established artificial intelligence (AI) model, sensitivity, precision, F1-score, and specificity were calculated. The clinical utility of our AI model was also evaluated through observer studies involving six orthopaedic surgeons and six radiologists.

RESULTS

Our AI model showed a sensitivity, precision, and F1-score of 0.78, 0.68, and 0.72 (per slice) and 0.75, 0.36, and 0.48 (per lesion), respectively. The observer studies revealed that our AI model had comparable sensitivity to orthopaedic or radiology experts and improved the sensitivity and F1-score of residents.

CONCLUSION

We developed a novel DL-based AI model for detecting osteolytic bone metastases in the thoracolumbar spine. Although further improvement in accuracy is needed, the current AI model may be applied to current clinical practice.

LEVEL OF EVIDENCE

Level III.

Incidence rate of osteonecrosis of jaw after cancer treated with bisphosphonates and denosumab: A systematic review and meta-analysis

OBJECTIVES

This study aimed to assess the overall incidence of osteonecrosis of the jaw (ONJ) caused by bisphosphonates and denosumab when used for controlling bone cancer metastasis or as adjuvant therapy.

SUBJECTS AND METHODS

A systematic search of the PubMed, Embase, and Cochrane Library databases and major meetings' proceedings as of July 30, 2022, identified randomized controlled trials (RCTs) and observational trials that evaluated ONJ caused by denosumab or bisphosphonates. The total incidence and risk ratio (RR) for ONJ were calculated using a random-effects model.

RESULTS

A total of 42 003 patients with various solid tumors reported in 23 RCTs were included. The overall ONJ incidence in cancer patients receiving denosumab or bisphosphonates was 2.08% (95% CI 1.37-2.91; p < .01; I2  = 94.99%). Patients receiving denosumab had a higher ONJ incidence than those receiving bisphosphonates (RR 1.64, 95% CI 1.10-2.44; p < .05; I2  = 65.4%). Subgroup analyses showed that prostate cancer patients receiving denosumab and receiving zoledronic acid had the highest ONJ incidences, 5.0% and 3.0%, respectively. The incidence of ONJ induced by different doses was also different.

CONCLUSIONS

The incidence of ONJ caused by denosumab and bisphosphonates is low, the dose of the drug and the type of cancer have certain influence on ONJ. Therefore, clinicians should use the drug reasonably to improve the quality of life of patients.

The Use of Microspheres for Cancer Embolization Therapy: Recent Advancements and Prospective

Embolization therapy involving biomaterials has improved the therapeutic strategy for most liver cancer treatments. Developing biomaterials as embolic agents has significantly improved patients' survival rates. Various embolic agents are present in liquid agents, foam, particulates, and particles. Some of the most applied embolic agents are microparticles, such as microspheres (3D micrometer-sized spherical particles). Microspheres with added functionalities are currently being developed for effective therapeutic embolization. Their excellent properties of high surface area and capacity for being loaded with radionuclides and alternate active or therapeutic agents provide an additional advantage to overcome limitations from traditional cancer treatments. Microspheres (non-radioactive and radioactive) have been widely used and explored for localized cancer treatment. Non-radioactive microspheres exhibit improved clinical performance as drug delivery vehicles in chemotherapy due to their controlled and sustained drug release to the target site. They offer better flow properties and are beneficial for the ease of delivery via injection procedures. In addition, radioactive microspheres have also been exploited for use as an embolic platform in internal radiotherapy as an alternative to cancer treatment. This short review summarizes the progressive development of non-radioactive and radioactive embolic microspheres, emphasizing material characteristics. The use of embolic microspheres for various modalities of therapeutic arterial embolization and their impact on therapeutic performance are also discussed.

CircMMP2(6,7) Cooperates with β-Catenin and PRMT5 to Disrupt Bone Homeostasis and Promote Breast Cancer Bone Metastasis

The bone is the most common site of distant metastasis of breast cancer, which leads to serious skeletal complications and mortality. Understanding the mechanisms underlying breast cancer bone metastasis would provide potential strategies for the prevention and treatment of breast cancer bone metastasis. In this study, we identified a circular RNA that we named circMMP2(6,7) that was significantly upregulated in bone metastatic breast cancer tissues and correlated with breast cancer-bone metastasis. Upregulation of circMMP2(6,7) dramatically enhanced the metastatic capability of breast cancer cells to the bone via inducing bone metastatic niche formation by disrupting bone homeostasis. Mechanistically, circMMP2(6,7) specifically bound to the promoters of bone-remodeling factors calcium-binding protein S100A4 and carbohydrate-binding protein LGALS3 and formed a complex with β-catenin and arginine methyltransferase PRMT5, eliciting histone H3R2me1/H3R2me2s-induced transcriptional activation. Treatment with GSK591, a selective PRMT5 inhibitor, effectively inhibited circMMP2(6,7)/β-catenin/PRMT5 complex-induced breast cancer bone metastasis. These findings reveal a role for circMMP2(6,7) in bone homeostasis disruption and shed light on the mechanisms driving breast cancer bone metastasis.

SIGNIFICANCE

Upregulation of bone-remodeling factors S100A4 and LGALS3 mediated by a circMMP2(6,7)/β-catenin/PRMT5 complex generates a niche that supports breast cancer bone metastasis, identifying PRMT5 as a promising target for treating metastasis.

Different decision-making in spine metastasis management among radiation oncologists and orthopedic surgeons: a Korean online survey study

Purpose

To understand the current practice of radiation oncologists (ROs) and orthopedic surgeons (OSs) regarding spine metastasis.

Methods

In 2022, an internet-based survey was conducted for ROs and OSs who treat spinal metastasis in Korea. Respondents were asked to choose the treatment option for two clinical scenarios. Scenario 1 involved a case displaying symptoms of leg weakness due to spinal cord compression and Scenario 2 involved a case with back pain due to pathologic compression fracture. The survey also included a question that required respondents to rank the importance of 11 clinical factors that affect treatment decisions.

Results

Forty-nine ROs and 30 OSs responded to the survey. There were significant differences in treatment choices between two groups for both scenarios (P = 0.001). In Scenario 1, more OSs chose surgical resection than ROs (43.3% vs. 16.7%), while more ROs chose radiotherapy than OSs (83.3% vs. 53.3%). In Scenario 2, a similar proportion of OSs and ROs chose radiotherapy (OSs, 71.4% vs. ROs, 67.3%), while more OSs opted for prophylactic fixation after radiotherapy than ROs (95.0% vs. 42.4%). The top three factors influencing treatment decisions were general performance status, life expectancy, and spinal instability for both ROs and OSs. In both Scenarios 1 and 2, the treatment decisions of ROs changed significantly when clinical conditions related to these top three factors were altered.

Conclusion

Although ROs and OSs share the same factors influencing treatment decisions for spinal metastases, notable differences exist in their actual treatment preferences, with ROs preferring radiotherapy and OSs opting for surgical resection. Multidisciplinary discussions may be necessary to reduce the gap in decision-making.

Beyond boundaries: unraveling innovative approaches to combat bone-metastatic cancers

Evidence demonstrated that bones, liver, and lungs are the most common metastasis sites in some human malignancies, especially in prostate and breast cancers. Bone is the third most frequent target for spreading tumor cells among these organs and tissues. Patients with bone-metastatic cancers face a grim prognosis characterized by short median survival time. Current treatments have proven insufficient, as they can only inhibit metastasis or tumor progression within the bone tissues rather than providing a curative solution. Gaining a more profound comprehension of the interplay between tumor cells and the bone microenvironment (BME) is of utmost importance in tackling this issue. This knowledge will pave the way for developing innovative diagnostic and therapeutic approaches. This review summarizes the mechanisms underlying bone metastasis and discusses the clinical aspects of this pathologic condition. Additionally, it highlights emerging therapeutic interventions aimed at enhancing the quality of life for patients affected by bone-metastatic cancers. By synthesizing current research, this review seeks to shed light on the complexities of bone metastasis and offer insights for future advancements in patient care.

Clinicopathological Features of Metastasis to the Oral and Maxillofacial Region-Multicenter Study

BACKGROUND

This study aimed to investigate the clinicopathological features of metastases in the oral and maxillofacial regions.

METHODS

In this retrospective study, biopsy records were obtained from referral centers for oral and maxillofacial diagnosis in Brazil, Guatemala, Mexico, and South Africa.

RESULTS

A total of 120 cases were evaluated. Of these, 53.78% affected female patients, with a mean age of 57.64 years. Intraosseous lesions were more frequent, particularly in the posterior region of the mandible (49.58%). Clinically, most cases presented with symptomatic swelling, with an average evolution time of 25 months. The clinical diagnostic hypothesis in most instances was that of a malignant lesion. Breast cancer was the most common primary tumor location in females, while lung origin was most common in males. In most cases, the primary cancer was an adenocarcinoma (44.73%). The follow-up period was available for 29 cases, and out of these, 20 had died due to the disease.

CONCLUSION

Although this is a rare condition, clinicians should be aware that any oral lesions have the possibility of being metastatic, particularly in individuals with a previous history of cancer. The findings from this study could assist clinicians in prompt diagnosing these lesions and subsequent conducting oncologic assessments and treatment.

Immune checkpoint inhibitors in bone metastasis: Clinical challenges, toxicities, and mechanisms

Immune checkpoint inhibitors (ICIs) have revolutionized the field of anti-cancer therapy over the last decade; they provide durable clinical responses against tumors by inhibiting immune checkpoint proteins that canonically regulate the T cell-mediated immune response. Despite their success in many primary tumors and soft tissue metastases, ICIs function poorly in patients with bone metastases, and these patients do not have the same survival benefit as patients with the same primary tumor type (e.g., non-small cell lung cancer [NSCLC], urothelial, renal cell carcinoma [RCC], etc.) that has not metastasized to the bone. Additionally, immune-related adverse events including rheumatologic and musculoskeletal toxicities, bone loss, and increased fracture risk develop after treatment with ICIs. There are few preclinical studies that investigate the interplay of the immune system in bone metastases; however, the current literature suggests a role for CD8+ T cells and myeloid cell subsets in bone homeostasis. As such, this review focuses on findings from the clinical and pre-clinical studies that have investigated immune checkpoint blockade in the bone metastatic setting and highlights the need for more comprehensive investigations into the relationship between immune cell subsets, ICIs, and the bone-tumor microenvironment.

Management of metastatic bone disease of the pelvis: current concepts

PURPOSE

Metastatic disease of the pelvis is frequently associated with severe pain and impaired ambulatory function. Depending on the patient's characteristics, primary tumor, and metastatic pelvic disease, the treatment choice may be varied. This study aims to report on the current management options of metastatic pelvic disease.

METHODS

We comprehensively researched multiple databases and evaluated essential studies about current concepts of managing a metastatic bone disease of the pelvis, focusing on specific indications as well as on the result of treatment.

RESULTS

Pelvic metastases not in the periacetabular region can be managed with modification of weight-bearing, analgesics, bisphosphonates, chemotherapy and/or radiotherapy. Minimally invasive approaches include radiofrequency ablation, cryoablation, embolization, percutaneous osteoplasty, and percutaneous screw placement. Pathological or impending periacetabular fracture, excessive periacetabular bone defect, radioresistant tumor, and persistent debilitating pain despite non-surgical treatment and/or minimally invasive procedures can be managed with different surgical techniques. Overall, treatment can be divided into nonoperative, minimally invasive, and operative based on specific indications, the expectations of the patient and the lesion.

CONCLUSION

Different treatment modalities exist to manage metastatic pelvic bone disease. Decision-making for the most appropriate treatment should be made with a multidisciplinary approach based on a case-by-case basis.

Role of exosomes in prostate cancer bone metastasis

Bone is a preferred metastatic site of prostate cancer (PCa), and most patients with PCa metastases develop osteogenic bone metastasis, which manifests as disturbed bone structure and poor bone quality. However, the underlying mechanisms of PCa bone metastasis remain unclear. In recent years, increasing evidence has implicated extracellular vesicles, especially exosomes, in PCa bone metastasis. Exosomes are 30-150 nm in diameter, enclosing a cargo of biomolecules, such as DNA, RNA, and proteins. Exosomes play a functional role in intercellular communication, modulate the functions of recipient cells, and potentially modulate bone microenvironment changes, thereby influencing the development of PCa bone metastasis. This review summarizes the involvement of exosomes in the imbalance between bone resorption and formation, and establishing a pre-metastatic niche in bone marrow, as well as potential clinical applications of exosomes in therapeutic strategies for treating patients with advanced PCa with bone metastasis.

A Study of Oral Health Parameters and the Properties and Composition of Saliva in Oncological Patients with and without Medication-Related Osteonecrosis of the Jaw Who Take Bisphosphonates

Background and Objectives: The aim of this study was to examine how the status of the oral cavity, composition and properties of saliva change in oncological patients with and without Medication-Related Osteonecrosis of the Jaw (MRONJ) undergoing bisphosphonate therapy. Materials and Methods: A retrospective case-control study of 49 oncological patients using bisphosphonates (BPs) was conducted. The study population was divided into two groups-Group I consisted of 29 patients with MRONJ and Group II of 20 patients without MRONJ. The control group consisted of 32 persons without oncological history and without antiresorptive therapy. Standard dental examination included the assessment of the number of teeth remaining, teeth with caries and fillings, Approximal Plaque Index (API) and Bleeding on Probing (BOP). In terms of MRONJ, localization and stage were assessed. Laboratory tests of saliva included determination of pH and concentrations of Ca and PO₄ ions, total protein, lactoferrin, lysozyme, sIgA, IgA, cortisol, neopterin, activity of amylase at rest, and stimulated saliva. The buffering capacity and microbiological tests (Streptococcus mutans, Lactobacillus spp. load) of stimulated saliva were also determined. Results: There were no statistically significant differences between the selected oral parameters and saliva of Group I and Group II. Significant differences were found between Group I and the control group. BOP, lysozyme and cortisol concentration were higher, while the number of teeth with fillings, Ca and neopterin concentrations were lower in comparison to the control group. In Group I, a significantly higher percentage of patients with a high colony count (>10⁵) of Streptococcus mutans and Lactobacillus spp. was also found. The significant differences between Group II and the control group concerned the concentrations of lysozyme, Ca ions, sIgA, neopterin and the colony count of Lactobacillus spp. In the Group I patients who received a significantly higher cumulative dose of BP compared to the Group II, a significant positive correlation was found between the received BP dose and the BOP. Most MRONJ foci were stage 2 and were mainly located in the mandible. Conclusions: Among oncological patients with and without MRONJ undergoing BP therapy compared to the control group, there are statistically significant differences in the dental, periodontal and microbiological status and in the composition of the saliva. Particularly noteworthy are the statistically significant differences in the decreased level of Ca ions, the increased level of cortisol and the elements of saliva related to the immune response (lysozyme, sIgA, neopterin). Additionally, a higher cumulative dose of BPs may affect the susceptibility to the development of osteonecrosis of the jaws. Patients undergoing antiresorptive therapy should receive multidisciplinary medical care, including dental care.

Comparison of 99m Tc-methylenediphosphonate and 68 Ga-BPAMD PET/computed tomography imaging in bone metastasis

OBJECTIVE

Bone is considered as the third most common site of metastases, besides lung and liver. Early detection of skeletal metastases aids in better management of skeletal-related events. In the present study cold kit-based 2,2 ' ,2 '' -(10-(2-((diphosphonomethyl)amino)-2-oxoethyl)-1,4,7,10-tetraazacyclododecane-1,4,7-triyl) triacetic acid (BPAMD) was labeled with 68 Ga. The radiolabeling parameters and clinical evaluation in patients with suspected bone metastases were compared with routinely used 99m Tc-methylenediphosphonate ( 99m Tc-MDP).

METHODOLOGY

The kit components of MDP were incubated with at room temperature for 10 min, followed by radiochemical purity testing using thin-layer chromatography. For radiolabeling of BPAMD, the cold kit components reconstituted in 400 μL of HPLC grade water were transferred and incubated with 68 GaCl 3 in the reactor vessel of the fluidic module at 95°C for 20 min. Radiochemical yield and purity were determined with instant thin-layer chromatography using 0.5 M sodium citrate as mobile phase. For clinical evaluation, patients ( n  = 10) with suspected bone metastases were enrolled. 99m Tc-MDP and 68 Ga-BPAMD scans were performed on two different days in random order. Imaging outcomes were noted and compared.

RESULTS

Radiolabeling of both tracers is facile using cold kit, although BPAMD requires heating. The radiochemical purity was observed to be greater than 99% for all preparations. Both MDP and BPAMD detected skeletal lesions; however, additional lesions were detected in total of seven patients which were not visualized clearly on 99m Tc-MDP scan.

CONCLUSION

BPAMD can be easily tagged with 68 Ga using cold kits. The radiotracer is suitable and efficient for detection of bone metastases using PET/computed tomography.

Nanoparticle-mediated synergistic drug combination for treating bone metastasis

Bone metastasis at an advanced disease stage is common in most solid tumors and is untreatable. Overexpression of receptor activator of nuclear factor κB ligand (RANKL) in tumor-bone marrow microenvironment drives a vicious cycle of tumor progression and bone resorption. Biodegradable nanoparticles (NPs), designed to localize in the tumor tissue in bone marrow, were evaluated in a prostate cancer model of bone metastasis. The combination treatment, encapsulating docetaxel, an anticancer drug (TXT-NPs), and Denosumab, a monoclonal antibody that binds to RANKL (DNmb-NPs), administered intravenously regressed the tumor completely, preventing bone resorption, without causing any mortality. With TXT-NPs alone treatment, after an initial regression, the tumor relapsed and acquired resistance, whereas DNmb-NPs alone treatment was ineffective. Only in the combination treatment, RANKL was not detected in the tumor tibia, thus negating its role in tumor progression and bone resorption. The combination treatment was determined to be safe as the vital organ tissue showed no increase in inflammatory cytokine or the liver ALT/AST levels, and animals gained weight. Overall, dual drug treatment acted synergistically to modulate the tumor-bone microenvironment with encapsulation enhancing their therapeutic potency to achieve tumor regression.

Prostate cancer bone metastases biology and clinical management (Review)

Prostate cancer (PCa) is one of the most prominent causes of cancer-related mortality in the male population. A highly impactful prognostic factor for patients diagnosed with PCa is the presence or absence of bone metastases. The formation of secondary tumours at the bone is the most commonly observed site for the establishment of PCa metastases and is associated with reduced survival of patients in addition to a cohort of life-debilitating symptoms, including mobility issues and chronic pain. Despite the prevalence of this disease presentation and the high medical relevance of bone metastases, the mechanisms underlying the formation of metastases to the bone and the understanding of what drives the osteotropism exhibited by prostate tumours remain to be fully elucidated. This lack of in-depth understanding manifests in limited effective treatment options for patients with advanced metastatic PCa and culminates in the low rate of survival observed for this sub-set of patients. The present review aims to summarise the most recent promising advances in the understanding of how and why prostate tumours metastasise to the bone, with the ultimate aim of highlighting novel treatment and prognostic targets, which may provide the opportunity to improve the diagnosis and treatment of patients with PCa with bone metastases.

Bone metastases do not affect the measurement uncertainties of a global digital volume correlation algorithm

Introduction: Measurement uncertainties of Digital Volume Correlation (DVC) are influenced by several factors, like input images quality, correlation algorithm, bone type, etc. However, it is still unknown if highly heterogeneous trabecular microstructures, typical of lytic and blastic metastases, affect the precision of DVC measurements.

Methods: Fifteen metastatic and nine healthy vertebral bodies were scanned twice in zero-strain conditions with a micro-computed tomography (isotropic voxel size = 39 μm). The bone microstructural parameters (Bone Volume Fraction, Structure Thickness, Structure Separation, Structure Number) were calculated. Displacements and strains were evaluated through a global DVC approach (BoneDVC). The relationship between the standard deviation of the error (SDER) and the microstructural parameters was investigated in the entire vertebrae. To evaluate to what extent the measurement uncertainty is influenced by the microstructure, similar relationships were assessed within sub-regions of interest.

Results: Higher variability in the SDER was found for metastatic vertebrae compared to the healthy ones (range 91-1030 με versus 222–599 με). A weak correlation was found between the SDER and the Structure Separation in metastatic vertebrae and in the sub-regions of interest, highlighting that the heterogenous trabecular microstructure only weakly affects the measurement uncertainties of BoneDVC. No correlation was found for the other microstructural parameters. The spatial distribution of the strain measurement uncertainties seemed to be associated with regions with reduced greyscale gradient variation in the microCT images.

Discussion: Measurement uncertainties cannot be taken for granted but need to be assessed in each single application of the DVC to consider the minimum unavoidable measurement uncertainty when interpreting the results.

Targeting bone cancer with 4-Allylbenzene-1,2-diol purified from Piper betle L.: an in silico and cytotoxicity scrutiny

Piper betle L., a well-known medicinal plant with rich source of bioactive compounds, is widely used in several therapeutics. The present study was performed to scrutinize the anti-cancer potential of compounds P. betle petiole by means of in silico studies, purification of 4-Allylbenzene-1,2-diol from petioles and assessing its cytotoxicity on bone cancer metastasis. Subsequent to SwissADME screening, 4-Allylbenzene-1,2-diol and Alpha terpineol were chosen for molecular docking together with eighteen approved drugs against fifteen important bone cancer targets accompanied with molecular dynamics simulation studies. 4-Allylbenzene-1,2-diol was found to be multi-targeting, interacted effectively with all targets, particularly exhibited good stability with MMP9 and MMP2 during molecular dynamics simulations and Molecular Mechanics- Generalized Born and Surface Area (MM-GBSA) analysis using Schrodinger. Later, the compound was isolated, purified and the cytotoxicity studies on MG63 bone cancer cell lines confirmed the cytotoxicity nature (75.98% at 100 µg/ml concentration). The results demonstrated the compound as a matrix metalloproteinase inhibitor, and therefore 4-Allylbenzene-1,2-diol may possibly be prescribed in targeted therapy for alleviating the bone cancer metastasis upon further wet lab experimental validations.Communicated by Ramaswamy H. Sarma.

Web-Based Nomograms for Overall Survival and Cancer-Specific Survival of Bladder Cancer Patients with Bone Metastasis: A Retrospective Cohort Study from SEER Database

BACKGROUND

Our study aimed to explore the prognostic factors of bladder cancer with bone metastasis (BCBM) and develop prediction models to predict the overall survival (OS) and cancer-specific survival (CSS) of BCBM patients.

METHODS

A total of 1438 patients with BCBM were obtained from the SEER database. Patients from 2010 to 2016 were randomly divided into training and validation datasets (7:3), while patients from 2017 were divided for external testing. Nomograms were established using prognostic factors identified through Cox regression analyses and validated internally and externally. The concordance index (C-index), calibration plots, and time-dependent receiver operating characteristic (ROC) curves were used to evaluate the discrimination and calibration of nomogram models, while decision curve analyses (DCA) and Kaplan-Meier (KM) curves were used to estimate the clinical applicability.

RESULTS

Marital status, tumor metastasis (brain, liver, and lung), primary site surgery, and chemotherapy were indicated as independent prognostic factors for OS and CSS. Calibration plots and the overall C-index showed a novel agreement between the observed and predicted outcomes. Nomograms revealed significant advantages in OS and CSS predictions. AUCs for internal and external validation were listed as follows: for OS, 3-month AUCs were 0.853 and 0.849; 6-month AUCs were 0.873 and 0.832; 12-month AUCs were 0.825 and 0.805; for CSS, 3-month AUCs were 0.849 and 0.847; 6-month AUCs were 0.870 and 0.824; 12-month AUCs were 0.815 and 0.797, respectively. DCA curves demonstrated good clinical benefit, and KM curves showed distinct stratification performance.

CONCLUSION

The nomograms as web-based tools were proved to be accurate, efficient, and clinically beneficial, which might help in patient management and clinical decision-making for BCBM patients.

Use of Glucocorticoids in Patients With Cancer: Potential Benefits, Harms, and Practical Considerations for Clinical Practice

PURPOSE

Glucocorticoids are commonly used in patients with cancer for symptom relief or as part of their anticancer treatment. Despite their frequent use, indications and dosing regimens are not exclusively evidence-based and can come with a multitude of adverse effects, some of which can be life-threatening. The objective of this review is to update our current state of knowledge on the use of glucocorticoids in adult patients with cancer.

METHODS AND MATERIALS

A comprehensive literature review (1949-2022) was conducted using search terms "glucocorticoids," "corticosteroids," and "cancer." Information was organized by main concepts including indications, potential benefits, and prevention and management of common side effects of glucocorticoid therapy, in addition to appropriate dosing and taper regimens.

RESULTS

Glucocorticoids can be highly effective in improving outcomes and quality of life in patients with cancer. Their uses include management of disease manifestations, symptoms, and complications of cancer treatment. The lowest effective dose should be used and treatment duration should be minimized as clinically feasible. Side effects can be minimized by careful monitoring, continued assessment of benefits versus harms, and preventative measures for expected side effects.

CONCLUSIONS

This review provides general principles and practical recommendations on the use of glucocorticoids in patients with cancer. Further prospective studies on the outcomes of patients on glucocorticoids may help guide practice.

The link between bone-derived factors osteocalcin, fibroblast growth factor 23, sclerostin, lipocalin 2 and tumor bone metastasis

The skeleton is the third most common site of metastatic disease, which causes serious bone complications and short-term prognosis in cancer patients. Prostate and breast cancers are responsible for the majority of bone metastasis, resulting in osteolytic or osteoblastic lesions. The crosstalk between bone cells and their interactions with tumor cells are important in the development of lesions. Recently, both preclinical and clinical studies documented the clinical relevance of bone-derived factors, including osteocalcin (OC) and its undercarboxylated form (ucOC), fibroblast growth factor 23 (FGF23), sclerostin (SCL), and lipocalin 2 (LCN2) as prognostic tumor biomarkers and potential therapeutic targets in bone metastasis. Both OC and ucOC could be useful targets for the prevention of bone metastasis in breast cancer. Moreover, elevated OC level may be a metastatic marker of prostate cancer. FGF23 is particularly important for those forms of cancer that primarily affect bone and/or are characterized by bone metastasis. In other tumor entities, increased FGF23 level is enigmatic. SCL plays a significant role in the pathogenesis of both osteolytic and osteoblastic lesions, as its levels are high in metastatic breast and prostate cancers. Elevated expression levels of LCN2 have been found in aggressive subtypes of cancer. However, its role in anti-metastasis varies significantly between different cancer types. Anyway, all aforementioned bone-derived factors can be used as promising tumor biomarkers. As metastatic bone disease is generally not curable, targeting bone factors represents a new trend in the prevention of bone metastasis and patient care.

Bone metastatic carcinoma coexisting with plasma cell myeloma: a case report

OBJECTIVE

Multiple myeloma is a clonal plasma cell proliferation often causing bone lytic lesions. It is sometimes challenging to differentiate these lytic lesions associated with multiple myeloma from bone destruction due to a metastasis. Although coexistence of solid tumors and plasma cell myeloma in one patient has been described, synchronous skeletal metastases from both neoplasms occurring in the same bone lesion is exceptional. Indeed, only one case has been reported in the literature.

CASE PRESENTATION

Herein, we report a case involving a 68-year-old Caucasian male patient admitted to our department for coronavirus disease 2019 infection with incidental finding of multiple lytic bone lesions during hospitalization. Laboratory tests revealed an increased immunoglobulin G kappa M protein and high levels of carbohydrate antigen 19-9. Bone marrow aspiration showed increased atypical plasma cells consistent with multiple myeloma. Percutaneous image-guided biopsy of one of the osteolytic lesions was performed. Pathological examination identified both plasma cell neoplasm and poorly differentiated metastatic carcinoma within the same bone lytic lesions.

CONCLUSION

The present case raises awareness among clinicians and pathologists that clinical and radiologic suspicion of multiple myeloma may be within the spectrum of second primary malignancies.

Role of Interleukin-1 family in bone metastasis of prostate cancer

Prostate cancer (PCa) is one of the most fatal diseases in male patients with high bone metastatic potential. Bone metastasis severely shortens overall survival and brings skeletal-related events (SREs) which reduces the life quality of patients, and this situation is currently regarded as irreversible and incurable. The progression and metastasis of PCa are found to be closely associated with inflammatory cytokines and chemokines. As pivotal members of inflammatory cytokines, Interleukin-1 (IL-1) family plays a crucial role in this process. Elevated expression of IL-1 family was detected in PCa patients with bone metastasis, and accumulating evidences proved that IL-1 family could exert vital effects on the progression and bone metastasis of many cancers, while some members have dual effects. In this review, we discuss the role of IL-1 family in the bone metastasis of PCa. Furthermore, we demonstrate that many members of IL-1 family could act as pivotal biomarkers to predict the clinical stage and prognosis of PCa patients. More importantly, we have elucidated the role of IL-1 family in the bone metastasis of PCa, which could provide potential targets for the treatment of PCa bone metastasis and probable directions for future research.

Malignant bone tumors around the knee: A single-center experience

Aim: This study aimed to determine the frequency of malignant bone tumors (primary and metastatic) seen around the knee in our region, the patients’ type and demographic characteristics, and the treatments’ outcomes. Material and Method: A retrospective analysis of the patients who were diagnosed and treated with histopathologically malignant tumors in the knee region in our hospital between 2004-2021 was performed from the hospital database. Patients’ complaints, demographic information, and diagnostic and imaging findings were examined. In addition, tumor types, tumor localization, and treatments applied were analyzed. Results: Malignant bone tumor was detected in 88 (35.7%) of 246 patients included in the study. The patients were 48 women and 40 men, with a mean age of 39.72±21.8 (6-76 years). A total of 88 patients were divided into the pediatric group (&lt;18 years; n=39) and the adult group (≥18 years; n=49). The most common tumors were osteosarcoma in 54 (61.3%) and metastatic tumors in 22 (25%) patients. The most common localization of tumors was the distal femur with a rate of 75%. Metastasis was detected in 12 (18.2%) of 66 patients treated and followed up for primary malignant bone tumors. Limb sparing surgery was performed in 70 (79.5%), and various levels of amputation were performed in 14 (15.9%). Palliative radiotherapy was applied to two patients with metastatic lesions, while two patients who were in the neoadjuvant chemotherapy period died. The 5-year overall survival was 63.7%. Pediatric and adult age groups did not differ significantly in terms of survival (p=0.74), gender (p=0.585), and metastasis development (p=0.53). Conclusion: The knee is a region that requires attention regarding bone tumors around it. As malignant bone tumors are rarely seen around the knee, a misdiagnosis may be made, and appropriate treatment may be delayed. Although the first diagnosis to come to mind for patients presenting with knee pain is trauma and growing pains, it must not be forgotten that a tumor could be the cause.

Clinical Outcomes and Their Prognostic Factors among Cervical Cancer Patients with Bone Recurrence

Background

Bone recurrence occurs in 0.75%-8% of cervical cancer patients after primary treatment. Only a few previous studies have reported on survival times associated with prognostic factors for bone recurrent cervical cancer. This study aimed to evaluate the oncological outcomes and their predictors among cervical cancer patients with bone recurrence.

Methods

The medical records of cervical cancer patients with bone recurrence who received primary treatment at Songklanagarind Hospital from January 2002 to December 2017 were retrospectively reviewed. Prognostic factors were identified using a Cox regression model.

Results

The study included 6,354 cervical cancer patients, of whom 98 (1.54%) had bone recurrence at a median time of 25 months after the primary treatment (range 4.9-136 months). The most frequent site of bone recurrence was the spine (81.00%); the two most common visceral coexisting recurrence sites were the lungs and the liver. The median recurrence-free interval (RFI) was 21 months. Of the patients with recurrence, 75 (76.50%) were treated with combined radiation therapy and chemotherapy. The one-year overall survival (OS) after recurrence was 22.70%. On multivariate analysis, age under 60 years at the time of recurrence diagnosis (hazard ratio [HR] = 2.48, 95% CI = 1.47-4.18, p=0.001) and an RFI less than 21 months (HR = 1.63, 95% CI = 1.04-2.55, p=0.03) were independent prognostic factors for OS after recurrence.

Conclusion

Bone recurrence in cervical cancer patients is rare and is associated with poor survival. Our study found that age and RFI were significant prognostic factors for OS in cervical cancer patients with bone recurrence.

Outcomes of first-line anti-PD-L1 blockades combined with brain radiotherapy for extensive-stage small-cell lung cancer with brain metastasis

INTRODUCTION

Anti-programmed cell death-ligand 1 (Anti-PD-L1) blockades have become the first-line treatment of extensive-stage small-cell lung cancer (ES-SCLC) from CASPIAN and IMpower133 trials. SCLC has a high incidence of brain metastasis (BM) and brain radiotherapy (BRT) is the main local treatment method, but there is limited data on the BRT-immunotherapy scheme. The aim of the retrospective study is to investigate the clinical efficacy and safety of the first-line anti-PD-L1 blockades combined with BRT in ES-SCLC with BM.

METHODS

Patients with newly diagnosed ES-SCLC with baseline BMs at Shandong Cancer Hospital and Research Institute between 2017 and 2021 were selected. Patients were divided into the anti-PD-L1+BRT group and BRT group. We also assessed the leukoencephalopathy in both groups.

RESULTS

A total of 46 patients were selected. Fifteen were divided into anti-PD-L1+BRT group and 31 to BRT group. The median overall survival (OS) was not reached (NR) vs 15.9 m (P = 0.172). Progression-free survival (PFS) was numerically prolonged with anti-PD-L1 blockades, but the significance was not reached (median: 9.4 m vs 7.4 m, P = 0.362). The median intracranial PFS was not improved, neither (median: 8.2 m vs 8.9 m, P = 0.620). Objective response rate (ORR) in the two groups was 73.33% vs 77.42% (P = 0.949) and disease control rate (DCR) was both 100%. Intracranial ORR and DCR were 53.33% vs 70.97% (P = 0.239) and 73.33% vs 80.65% (P = 0.855), respectively. There was no significant difference in leukoencephalopathy incidence between the two groups.

CONCLUSION

The combination of first-line anti-PD-L1 blockades with BRT did not confer a significant survival benefit in ES-SCLC with BM, without enhancing cranial neurotoxicity.

Use of paclitaxel carried in lipid core nanoparticles in patients with late-stage solid cancers with bone metastases: Lack of toxicity and therapeutic benefits

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LDE-PTX at 175 mg/m²/3wk dose was devoid of toxicity at > 3rd line treatment.

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Among 18 LDE-PTX treated patients, 9 had PFS > 6 months and 2 had PFS > 1 yr.

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LDE-PTX diminished bone pain and improved quality of life in all treated patients.

^{Patients with heavily pretreated, late-stage cancer and bone metastasis are usually poor candidates for further chemotherapy. Previously, we showed that association to lipid nanoparticles (LDE) drastically decreases the toxicity of anti-cancer drugs. Here, we tested the hypothesis that paclitaxel (PTX) carried in LDE could benefit end-of-life patients with painful bone metastases that had been previously treated with conventional PTX. Methods: Eighteen consecutive patients with late-stage cancer, 8 with breast, 5 with prostate and 5 with lung carcinoma, aged 59±9 years, were included in this study. All were receiving opioid medication. LDE-PTX was administered at 175 mg/m 2 every 3 weeks until disease progression. Clinical imaging examinations and serum biochemistry determinations were performed to monitor disease progression. Intensity of bone pain, use of opioid medications and occurrence of pathological bone fractures were also evaluated. Results: In total, 104 chemotherapy cycles were performed and none of the patients showed clinical and laboratorial toxicities or pathological bone fractures. In all patients, pain was reduced so as to allow substitution of non-opioid for opioid medication. Median progression-free survival (PFS) was four months (95% CI 2.4-5.5), but in five patients PFS was longer than 6 months. Conclusions: Absence of observable clinical and laboratorial toxicities from LDE-PTX treatment, improvement of bone pain and the possible effect on PFS in some patients, despite previous use of conventional PTX, suggest that LDEPTX merits further clinical investigation.}

Exploration of the Effect of Icariin on Nude Mice with Lung Cancer Bone Metastasis via the OPG/RANKL/RANK System

Epimedium is a traditional Chinese medicine that is most commonly prescribed by practitioners of Chinese medicine for the clinical treatment of malignant tumor bone metastasis. The main component of Epimedium is icariin (ICA). Studies have shown that ICA inhibits bone resorption of osteoclasts through the OPG/RANKL/RANK signaling pathway. Osteoclasts are the only cells in the body that have a bone-destroying capability. The OPG/RANKL/RANK system consists of cytokines that play major roles in osteoclast formation. Therefore, our study selected the OPG/RANKL/RANK system as the research target to investigate the effect of ICA on nude mice with lung cancer bone metastasis. We established the model of bone metastasis in nude mice, intervened the model with icariin and zoledronic acid, and detected the levels of OPG and RANKL by ELISA and western blot. The results showed that ICA had a significant inhibitory effect on bone metastases in nude mice. ICA achieved its antibone metastasis effect in nude mice with lung cancer via inhibiting RANKL expression and simultaneously increasing OPG expression. ICA not only alleviated osteolytic bone destruction caused by bone metastases, but it also reduced weight loss in tumor-bearing nude mice at the late stage of the experiment. The role of ICA in preventing bone metastasis of lung cancer merits further investigation.

Outcomes and prognostic factors after surgery for bone metastases in the extremities and pelvis: A retrospective analysis of 140 patients

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Pathological fracture, visceral metastasis and lung cancer were negative prognostic factors for patients with bone metastases in the extremities and pelvis.

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Complications occurred in every fourth patient within the first 30 postoperative days.

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No significant differences in short- and long-term outcomes were observed between endoprosthetic replacement and internal fixation.

Background

Methods

Results

Conclusions

A Novel Nomogram for Predicting Morbidity Risk in Patients with Secondary Malignant Neoplasm of Bone and Bone Marrow: An Analysis Based on the Large MIMIC-III Clinical Database

Objective

Bone and bone marrow are the third most frequent sites of metastases from many cancers and are associated with low survival and high morbidity rates. Currently, there are no effective bedside tools to predict the morbidity risk of these patients in general intensive care units (ICUs). The main objective of this study was to establish and validate a nomogram to predict the morbidity risk of patients with bone and bone marrow metastases.

Methods

Data on patients with bone and bone marrow metastases were extracted from the Medical Information Mart for Intensive Care III (MIMIC-III) database. The patients were divided into training and validation cohorts. The data were analyzed using univariate and multivariate Cox regression methods. Factors significantly and independently prognostic of survival were used to construct a nomogram predicting 30-day morbidity. The nomogram was validated by various methods, including Harrell’s concordance index (C-index), area under the receiver operating characteristic curve (AUC), calibration curve, integrated discrimination improvement (IDI), net reclassification index (NRI), and decision curve analysis (DCA).

Results

The study included 610 patients in the training cohort and 262 in the validation cohort. Multivariate Cox regression analysis showed that temperature, SpO₂, Sequential Organ Failure Assessment (SOFA) score, Oxford Acute Severity of Illness Score (OASIS), comorbidities with coagulopathy, white blood cell count, heart rate, and respiratory rate were independent predictors of patient survival. The resulting nomogram had good discriminative ability, as shown by high AUCs, and was well calibrated, as demonstrated by calibration curves. Improvements in NRI and IDI values suggested that the nomogram was superior to the SOFA scoring system. DCA curves revealed that the nomogram showed good value in clinical applications.

Conclusion

This prognostic nomogram, based on demographic and laboratory parameters, was predictive of the 30-day morbidity rate in patients with secondary malignant neoplasms of the bone and bone marrow, suggesting its applicability in clinical practice.

Application of additively manufactured 3D scaffolds for bone cancer treatment: a review

Bone cancer is a critical health problem on a global scale, and the associated huge clinical and economic burdens are still rising. Although many clinical approaches are currently used for bone cancer treatment, these methods usually affect the normal body functions and thus present significant limitations. Meanwhile, advanced materials and additive manufacturing have opened up promising avenues for the development of new strategies targeting both bone cancer treatment and post-treatment bone regeneration. This paper presents a comprehensive review of bone cancer and its current treatment methods, particularly focusing on a number of advanced strategies such as scaffolds based on advanced functional materials, drug-loaded scaffolds, and scaffolds for photothermal/magnetothermal therapy. Finally, the main research challenges and future perspectives are elaborated.

Real-world patient-reported outcomes of breast cancer or prostate cancer patients receiving antiresorptive therapy for bone metastases: Final results of the PROBone Registry Study

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Bone metastases present the main cause of morbidity and deterioration of QoL.

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Time of initiation of antiresorptive treatment is still discussed controversially.

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Pain levels at therapy start are prognostic for further course of pain and QoL.

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Time requirements for cancer treatment are a burden especially for younger patients.

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Early initiation of bone-targeted agents is important for patients’ QoL.

Background

In breast cancer and prostate cancer patients, bone metastases (BM) present the main cause of morbidity and often cause debilitating pain, impaired functioning and subsequent deterioration of quality of life (QoL). The management of BM is still challenging. Maintenance or improvement in QoL is the main goal of treatment. Antiresorptive treatment, such as denosumab and bisphosphonates, can help to reduce the frequency of skeletal complications, to control bone pain and potentially to improve QoL. The optimal time point for initiation of antiresorptive therapy is still discussed controversially. In patients with BM, bone pain can be used as a surrogate measure of QoL. However, limited data exist on health-related QoL in patients with BM under antiresorptive treatment. The PROBone registry study evaluated complaints and limitations caused by BM of breast and prostate cancer patients using patient-reported outcomes (PROs) in real-world in Germany.

Methods

Between 2014 and 2019, 500 patients with histological confirmation of advanced breast or prostate cancer, diagnosed with BM at start of their first antiresorptive therapy were prospectively enrolled in 65 outpatient-centers specialized in medical oncology across Germany. Changes of QoL were assessed monthly from baseline until a maximum of 12 months using the validated pain score Functional Assessment of Cancer Therapy Quality of Life Measurement in patients with bone pain (FACT-BP) supplemented by questions on general pain and on the impact of time spent for treatment of illness on patients’ daily activities. Statistical analysis was performed descriptively by relative and absolute frequencies.

Results

In total, 486 patients were eligible for final analysis, of these 310 were diagnosed with breast cancer and 176 with prostate cancer. Median age was 67 years for breast cancer and 76 years for prostate cancer patients. 79.7% of breast cancer and 59.7% of prostate patients started antiresorptive treatment within 3 months after diagnosis of BM. More than 75% of patients suffered from bone pain at study inclusion. In total 52% of breast cancer patients and 47.9% of prostate cancer patients reported to take pain medication during the observation period. In breast and prostate cancer patients an initial pain reduction after start of BTA was observed: General pain and bone pain levels as well as the median FACT-BP score showed a constant improvement over the first months and maintained stable at a constant level afterwards. Subgroup analysis showed that patients without pain at baseline reported distinctly better FACT-BP scores throughout the whole observation period than patients with pain at baseline. Looking at time-stress (M)-scores, younger breast cancer patients (<65 years) showed highest burden especially during the first months of treatment.

Conclusions

Our results indicate overall good adherence to current guideline recommendation, with most breast and prostate cancer patients starting antiresorptive therapy within the first 3 months after diagnosis of BM. This point gains even more importance as our data support current recommendations by ESMO guidelines as well as by German evidence-based S3-guidelines for diagnosis and treatment of breast and prostate cancer to initiate bone-targeted agents (BTA) as soon as BM are diagnosed, to keep pain levels at the lowest level possible, to minimize the debilitating effects of metastatic bone pain and maintain a good QoL. Bone pain management by an early use of BTA following BM diagnosis might improve patient care.

The role of surgery in the treatment of metastatic bone tumor

Surgery for bone metastasis has two primary goals-palliative care to relieve pain, instability and paralysis, and tumor resection for curing the disease. Oncologically en bloc resection, followed by a reconstruction of the bone defect is the treatment of choice in single bone metastasis from renal cell carcinoma or thyroid cancer. Bone metastases may occur in the extremities, pelvis, or spine, and different resection and reconstruction methods depend on the regional anatomy. For instance, multiple options are available for reconstruction of the pelvis, especially for the acetabulum, including anatomical reconstruction using custom-made implants or recycled autologous bone grafting when a long-term prognosis is expected. Recently, for the spine, total en bloc spondylectomy is extensively performed despite the initial limitations of surgical invasiveness, such as blood loss. Principally, palliative surgery aims to maintain lasting bony stability with minimal surgical invasiveness. Intramedullary nails and plate fixation are frequently used in the extremities but the postoperative failure rate is relatively high. Therefore, surgeons should consider the use of long intramedullary nails and long-type stems for endoprosthesis reconstruction along with cement fixation to reduce the failure rate. Although short-term complications, such as dislocation, have been observed with endoprosthesis reconstruction, it is stable in the long-term follow-up. Percutaneous bone cement injection into the spine and pelvis is also effective and less invasive.

The presenting dental status of solid tumours with bone metastases requiring bone-targeting agents - part 4: miscellaneous cancers

This article discusses relevant information for the dental sector regarding metastatic cancers beyond breast and prostate cancer. Typically, tumour sites such as lung, renal, colorectal, gastrointestinal, thyroid, hepatic and pancreatic cancers are increasingly being referred for bone-targeting agents upon evidence of bone metastases.The current article explores the presenting dental status of these tumour groups on the background of survival outcomes. In addition, the article provides insight towards the complexity in achieving 'dental fitness' and whether 'dental stability' could be an alternative to consider via palliative dentistry in certain cases.

Artificial Intelligence in Bone Metastases: An MRI and CT Imaging Review

(1) Background: The purpose of this review is to study the role of radiomics as a supporting tool in predicting bone disease status, differentiating benign from malignant bone lesions, and characterizing malignant bone lesions. (2) Methods: Two reviewers conducted the literature search independently. Thirteen articles on radiomics as a decision support tool for bone lesions were selected. The quality of the methodology was evaluated according to the radiomics quality score (RQS). (3) Results: All studies were published between 2018 and 2021 and were retrospective in design. Eleven (85%) studies were MRI-based, and two (15%) were CT-based. The sample size was <200 patients for all studies. There is significant heterogeneity in the literature, as evidenced by the relatively low RQS value (average score = 22.6%). There is not a homogeneous protocol used for MRI sequences among the different studies, although the highest predictive ability was always obtained in T2W-FS. Six articles (46%) reported on the potential application of the model in a clinical setting with a decision curve analysis (DCA). (4) Conclusions: Despite the variability in the radiomics method application, the similarity of results and conclusions observed is encouraging. Substantial limits were found; prospective and multicentric studies are needed to affirm the role of radiomics as a supporting tool.

The presenting dental status of solid tumours with bone metastases requiring bone-targeting agents - part 1: an overview

Introduction Dental pre-assessment before bone-targeting agents (BTA) in oncology patients is a well-recognised practice; yet, guidance on this has typically been unable to differentiate between the intricacies of varying oncology groups. This study assesses the presenting dental status of oncology patients with bone metastases (BM) due to commence BTA, to determine whether differences exist with varying tumour groups.Materials and methods Data were retrospectively collected from a dedicated pre-BTA dental assessment clinic. Statistical analysis and observational data were used to compare patient and tumour demographics as well as to their peers via the Adult Dental Health Survey.Results A total of 492 patients with a solid tumour diagnosis and BM requiring BTA were included in this retrospective study. Demographics such as sex, age, smoking status and tumour site were all significant for the number of teeth present (p = 0.000). Furthermore, survival data post-BTA identified prostate, breast and thyroid groups surviving over 12 months following dental assessment (p <0.000). In contrast, the remaining groups such as lung, colorectal and gastrointestinal had poorer outcomes (p <0.000).Conclusion Pre-BTA dental assessment should consider and incorporate additional patient and tumour demographics to allow for a tailored and personalised dental treatment plan. Application of this principle would look to optimise oral function while considering tumour prognosis to avoid over- or under-prescribing pre-BTA dental treatment.

Musculoskeletal Applications of Magnetic Resonance-Guided Focused Ultrasound

Magnetic resonance-guided focused ultrasound (MRgFUS) is a novel noninvasive therapy that uses focused sound energy to thermally ablate focal pathology within the body. In the United States, MRgFUS is approved by the Food and Drug Administration for the treatment of uterine fibroids, palliation of painful bone metastases, and thalamotomy for the treatment of essential tremor. However, it has also demonstrated utility for the treatment of a wide range of additional musculoskeletal (MSK) conditions that currently are treated as off-label indications. Advantages of the technology include the lack of ionizing radiation, the completely noninvasive technique, and the precise targeting that offer unprecedented control of the delivery of the thermal dose, as well as real-time monitoring capability with MR thermometry. In this review, we describe the most common MSK applications of MRgFUS: palliation of bone metastases, treatment of osteoid osteomas, desmoid tumors, facet arthropathy, and other developing indications.

Efficacy and safety of magnetic resonance-guided focused ultrasound for the treatment of painful bone metastases: a systematic review and meta-analysis

OBJECTIVE

To report the safety and efficacy of magnetic resonance-guided focused ultrasound (MRgFUS) in the treatment of painful bone metastases through a systematic review and meta-analysis of pain scores before and after MRgFUS treatment and post-treatment adverse events.

MATERIALS AND METHODS

A comprehensive literature search of PubMed and Embase databases was performed for studies evaluating the efficacy and/or safety of MRgFUS. The mean difference of pain scores (10-point visual analogue scale or numerical rating scale) between baseline and 1-month/3-month pain scores was collected and analyzed in a pooled meta-analysis. Post-treatment adverse events based on the Common Terminology Criteria for Adverse Events (CTCAE) grading were recorded and the pooled prevalence was calculated.

RESULTS

A total of 33 studies published between 2007 and 2019 were collected, resulting in a total sample size of 1082 patients. The majority of the studies were prospective with a reported follow-up period of 3 months. The pooled proportion of patients that achieved pain relief from MRgFUS (complete response or partial response [≥ 2-point improvement of pain score]) was 79% (95% CI 73-83%). The pooled 1-month and 3-month mean difference in pain score were - 3.8 (95% CI - 4.3; - 3.3) and - 4.4 (95% CI - 5.0; - 3.7), respectively. The overall rate of high-grade (CTCAE grade 3 or higher) and low-grade (CTCAE grade 2 or lower) MRgFUS-related adverse events were 0.9% and 5.9%, respectively.

CONCLUSION

MRgFUS is an effective procedure that is able to provide significant pain palliation for patients with symptomatic bone metastases with a favorable safety profile.

Estimation of additional dosimetry from low-dose CT scan to 99mTc-HMDP SPECT/CT

INTRODUCTION

Currently, the addition of computed tomography (CT) to a gamma-camera has revolutionized nuclear medicine. Indeed the CT, because of its good spatial resolution, of the attenuation correction of the single photon emission computed tomography (SPECT) images and of a better anatomical localization of lesions, improves the sensitivity, specificity and accuracy of the examination. Despite the fact that the hybrid camera uses a low-dose non-diagnostic scanner, increases the overall delivered dose of radiation.

METHODS

The aim of this study was to evaluate the contribution of CT to the total effective dose of ^99mTc-HMDP (hydroxymethylenediphosphonate labelled with technetium 99 metastable) SPECT/CT for an adult oncologic population. This prospective study included 103 patients (75 women and 28 men) aged 28 to 79 years.

RESULTS

The mean effective doses of SPECT, CT and SPECT/CT were respectively 3.8 mSv, 3.3 mSv and 7.1 mSv, respectively. The average contribution of CT scans to the total effective dose for SPECT/CT examination was 45 ± 9.7%, and ranged from 10 to 67.4%. The lowest value was for the thorax area.

CONCLUSION

This radiation dose is not negligible. But, taking into account the benefit of hybrid imaging, this additional radiation remains justifiable. Nevertheless, the "As Low as Reasonably Achievable (ALARA)'' principle must be respected to ensure that the patient is not subjected to unnecessarily high levels of radiation.

Fracture Risk Evaluation of Bone Metastases: A Burning Issue

Major progress has been achieved to treat cancer patients and survival has improved considerably, even for stage-IV bone metastatic patients. Locomotive health has become a crucial issue for patient autonomy and quality of life. The centerpiece of the reflection lies in the fracture risk evaluation of bone metastasis to guide physician decision regarding physical activity, antiresorptive agent prescription, and local intervention by radiotherapy, surgery, and interventional radiology. A key mandatory step, since bone metastases may be asymptomatic and disseminated throughout the skeleton, is to identify the bone metastasis location by cartography, especially within weight-bearing bones. For every location, the fracture risk evaluation relies on qualitative approaches using imagery and scores such as Mirels and spinal instability neoplastic score (SINS). This approach, however, has important limitations and there is a need to develop new tools for bone metastatic and myeloma fracture risk evaluation. Personalized numerical simulation qCT-based imaging constitutes one of these emerging tools to assess bone tumoral strength and estimate the femoral and vertebral fracture risk. The next generation of numerical simulation and artificial intelligence will take into account multiple loadings to integrate movement and obtain conditions even closer to real-life, in order to guide patient rehabilitation and activity within a personalized-medicine approach.

Current Overview of Treatment for Metastatic Bone Disease

The number of patients with bone metastasis increases as medical management and surgery improve the overall survival of patients with cancer. Bone metastasis can cause skeletal complications, including bone pain, pathological fractures, spinal cord or nerve root compression, and hypercalcemia. Before initiation of treatment for bone metastasis, it is important to exclude primary bone malignancy, which would require a completely different therapeutic approach. It is essential to select surgical methods considering the patient’s prognosis, quality of life, postoperative function, and risk of postoperative complications. Therefore, bone metastasis treatment requires a multidisciplinary team approach, including radiologists, oncologists, and orthopedic surgeons. Recently, many novel palliative treatment options have emerged for bone metastases, such as stereotactic body radiation therapy, radiopharmaceuticals, vertebroplasty, minimally invasive spine stabilization with percutaneous pedicle screws, acetabuloplasty, embolization, thermal ablation techniques, electrochemotherapy, and high-intensity focused ultrasound. These techniques are beneficial for patients who may not benefit from surgery or radiotherapy.

Sites of Synchronous Distant Metastases, Prognosis, and Nomogram for Small Cell Lung Cancer Patients with Bone Metastasis: A Large Cohort Retrospective Study

Background

Small cell lung cancer (SCLC) is often associated with metastases at the time of diagnosis, and the bone is one of the most common sites. The primary aim of this study was to investigate the site of synchronous distant metastasis to other organs in SCLC patients with bone metastasis (BM) and develop a robust predictive prognostic model.

Methods

We retrospectively analyzed the data from patients diagnosed with SCLC with BM in the Surveillance, Epidemiology, and End Results database. Univariate and multivariate Cox analyses were used to identify independent prognostic factors. A prognostic nomogram was constructed and evaluated by calibration curves, receiver operating characteristic (ROC) curves, and decision curve analysis (DCA). Then, according to the sites of metastasis and treatment modality, all patients were stratified into several subgroups. The relationship among sites of metastasis, treatment modality, and overall survival was then analyzed.

Results

A total of 6253 patients were included. Independent prognostic factors for SCLC with BM were age, sex, primary site, radiotherapy, chemotherapy, brain metastasis, liver metastasis, and marital status. Calibration, ROC curves, and DCA indicated the excellent performance of the prognostic nomogram. The liver is the most common organ for extraskeletal metastases, followed by the lung. Patients with only BM had the longest mean survival time (9.30 ± 0.31 months). In the subgroup analysis, chemotherapy was an independent prognostic factor for all subgroups. In contrast, radiotherapy showed a positive effect on the prognosis of patients in all subgroups except those with bone and brain metastases and those with bone, lung, and brain metastases.

Conclusions

The prognostic nomogram is expected to be an accurate and personalized tool for predicting the prognosis of SCLC patients with BM. Additionally, the determination of the sites of synchronous extraskeletal metastases and the associated prognosis helps in treatment selection.

Modeling bystander effects that cause growth delay of breast cancer xenografts in bone marrow of mice treated with radium-223

RATIONALE

The role of radiation-induced bystander effects in cancer therapy with alpha-particle emitting radiopharmaceuticals remains unclear. With renewed interest in using alpha-particle emitters to sterilize disseminated tumor cells, micrometastases, and tumors, a better understanding of the direct effects of alpha particles and the contribution of the bystander responses they induce is needed to refine dosimetric models that help predict clinical benefit. Accordingly, this work models and quantifies the relative importance of direct effects (DE) and bystander effects (BE) in the growth delay of human breast cancer xenografts observed previously in the tibiae of mice treated with 223RaCl2.

METHODS

A computational model of MDA-MB-231 and MCF-7 human breast cancer xenografts in the tibial bone marrow of mice administered 223RaCl2 was created. A Monte Carlo radiation transport simulation was performed to assess individual cell absorbed doses. The responses of the breast cancer cells to direct alpha particle irradiation and gamma irradiation were needed as input data for the model and were determined experimentally using a colony-forming assay and compared to the responses of preosteoblast MC3T3-E1 and osteocyte-like MLO-Y4 bone cells. Using these data, a scheme was devised to simulate the dynamic proliferation of the tumors in vivo, including DE and BE propagated from the irradiated cells. The parameters of the scheme were estimated semi-empirically to fit experimental tumor growth.

RESULTS

A robust BE component, in addition to a much smaller DE component, was required to simulate the in vivo tumor proliferation. We also found that the relative biological effectiveness (RBE) for cell killing by alpha particle radiation was greater for the bone cells than the tumor cells.

CONCLUSION

This modeling study demonstrates that DE of radiation alone cannot explain experimental observations of 223RaCl2-induced growth delay of human breast cancer xenografts. Furthermore, while the mechanisms underlying BE remain unclear, the addition of a BE component to the model is necessary to provide an accurate prediction of the growth delay. More complex models are needed to further comprehend the extent and complexity of 223RaCl2-induced BE.