Bone-targeted agents and skeletal-related events in breast cancer patients with bone metastases: the state of the art

Comparative analysis of Denosumab and Zoledronic acid in advanced breast cancer patients receiving CDK4/6 inhibitors

A comparative analysis of Denosumab (DMAB) and Zoledronic Acid (ZA) was conducted in a real-world cohort of 864 patients with hormone receptor-positive, human epidermal growth factor receptor 2-negative advanced breast cancer with bone metastases, who were undergoing CDK4/6 inhibitors plus endocrine therapy. We evaluated the time to first skeletal-related events (SREs), progression-free survival (PFS), and overall survival (OS). To adjust for confounding variables, we utilized propensity score matching (PSM) and inverse probability of treatment weighting (IPTW) methodologies. In the unadjusted cohort, ZA was associated with a longer time to first SRE compared to DMAB (HR = 0.77, 95 % CI: 0.61-0.98, p = 0.031). Similar results were obtained in both the PSM (HR = 0.69, 95 % CI: 0.52-0.92, p = 0.011) and IPTW cohorts (HR = 0.74, 95 % CI: 0.63-0.87, p < 0.001), with ZA-treated patients showing an extended time to first SRE compared to those treated with DMAB. No differences in PFS and OS were observed between the two cohorts.

From conventional therapy to novel nano-based approaches. A focus on prostate cancer

The currently available clinical anticancer approaches pertaining to the treatment of prostate cancer are summarized here. After providing an overview of the main features of this highly impactful global disease, the currently available clinical treatments are briefly reviewed. Then, alternative and innovative nano-based therapeutic options that have been proposed or are currently being explored to significantly improve prostate cancer management (i.e. anti-prostate cancer polymeric nanoparticles loaded with drugs to promote their release and biological activity, including non-targeted and functionalized PLGA-PEG NPs and AuNPs), are introduced. Furthermore, the problem of gathering insights into the mechanistic aspects related to the fate of the nanoformulation in complex matrices, such as blood plasma, is addressed.

Oncologic Applications of Artificial Intelligence and Deep Learning Methods in CT Spine Imaging-A Systematic Review

In spinal oncology, integrating deep learning with computed tomography (CT) imaging has shown promise in enhancing diagnostic accuracy, treatment planning, and patient outcomes. This systematic review synthesizes evidence on artificial intelligence (AI) applications in CT imaging for spinal tumors. A PRISMA-guided search identified 33 studies: 12 (36.4%) focused on detecting spinal malignancies, 11 (33.3%) on classification, 6 (18.2%) on prognostication, 3 (9.1%) on treatment planning, and 1 (3.0%) on both detection and classification. Of the classification studies, 7 (21.2%) used machine learning to distinguish between benign and malignant lesions, 3 (9.1%) evaluated tumor stage or grade, and 2 (6.1%) employed radiomics for biomarker classification. Prognostic studies included three (9.1%) that predicted complications such as pathological fractures and three (9.1%) that predicted treatment outcomes. AI's potential for improving workflow efficiency, aiding decision-making, and reducing complications is discussed, along with its limitations in generalizability, interpretability, and clinical integration. Future directions for AI in spinal oncology are also explored. In conclusion, while AI technologies in CT imaging are promising, further research is necessary to validate their clinical effectiveness and optimize their integration into routine practice.

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.

Artificial Intelligence in Detection, Management, and Prognosis of Bone Metastasis: A Systematic Review

BACKGROUND

Metastasis commonly occur in the bone tissue. Artificial intelligence (AI) has become increasingly prevalent in the medical sector as support in decision-making, diagnosis, and treatment processes. The objective of this systematic review was to assess the reliability of AI systems in clinical, radiological, and pathological aspects of bone metastases.

METHODS

We included studies that evaluated the use of AI applications in patients affected by bone metastases. Two reviewers performed a digital search on 31 December 2023 on PubMed, Scopus, and Cochrane library and extracted authors, AI method, interest area, main modalities used, and main objectives from the included studies.

RESULTS

We included 59 studies that analyzed the contribution of computational intelligence in diagnosing or forecasting outcomes in patients with bone metastasis. Six studies were specific for spine metastasis. The study involved nuclear medicine (44.1%), clinical research (28.8%), radiology (20.4%), or molecular biology (6.8%). When a primary tumor was reported, prostate cancer was the most common, followed by lung, breast, and kidney.

CONCLUSIONS

Appropriately trained AI models may be very useful in merging information to achieve an overall improved diagnostic accuracy and treatment for metastasis in the bone. Nevertheless, there are still concerns with the use of AI systems in medical settings. Ethical considerations and legal issues must be addressed to facilitate the safe and regulated adoption of AI technologies. The limitations of the study comprise a stronger emphasis on early detection rather than tumor management and prognosis as well as a high heterogeneity for type of tumor, AI technology and radiological techniques, pathology, or laboratory samples involved.

Cost-Effectiveness Analysis of Denosumab in the Prevention of Skeletal-Related Events Among Patients With Breast Cancer With Bone Metastasis in India

PURPOSE

Denosumab is clinically superior to zoledronic acid (ZA) for preventing and delaying time to first and subsequent skeletal-related events (SREs) among patients with breast cancer (BC) with bone metastases. We evaluated the cost and health benefits of denosumab and ZA (once every 4 weeks and once every 12 weeks) among four different molecular subtypes of BC with bone metastases in India.

MATERIALS AND METHODS

A Markov model was developed in Microsoft Excel to estimate lifetime health consequences and resulting costs among cohort of 1,000 patients with BC with bone metastasis, for three intervention scenarios, namely denosumab (once every 4 weeks), ZA (once every 4 weeks), and ZA (once every 12 weeks). The health outcomes were measured in terms of SREs averted and quality-adjusted life-years (QALYs) gained. The cost of each intervention scenario was measured using both the health system and the patient's perspectives. Indirect costs because of lost productivity were not included. The future costs and outcomes were discounted at the standard rate of 3%.

RESULTS

Over a lifetime, the incremental number of SREs averted with use of denosumab once every 4 weeks (compared with ZA once every 4 weeks and once every 12 weeks) among patients with luminal A, luminal B, human epidermal growth factor receptor 2-enriched, and triple negative breast cancer were estimated as 0.39, 0.26, 0.25, and 0.19, respectively. The number of QALYs lived were slightly higher in the denosumab arm (1.45-2.80) compared with ZA once every 4 weeks and once every 12 weeks arms (1.44-2.78). However, denosumab once every 4 weeks was not found to be a cost-effective alternative for either of the four molecular subtypes of breast cancer. ZA once every 12 weeks was found to be a cost-effective option with an average cost-effectiveness ratio ranging between ₹68,254 and ₹73,636.

CONCLUSION

ZA once every 12 weeks is the cost-effective treatment option for BC with bone metastases in India. The present study findings hold significance for standard treatment guidelines under India's government-funded health insurance program.

Assessment of Spinal Metastases Surgery Risk Stratification Tools in Breast Cancer by Molecular Subtype

BACKGROUND

Breast cancer molecular features and modern therapies are not included in spine metastasis prediction algorithms.

OBJECTIVE

To examine molecular differences and the impact of postoperative systemic therapy to improve prognosis prediction for spinal metastases surgery and aid surgical decision making.

METHODS

This is a retrospective multi-institutional study of patients who underwent spine surgery for symptomatic breast cancer spine metastases from 2008 to 2021 at the Massachusetts General Hospital and Brigham and Women's Hospital. We studied overall survival, stratified by breast cancer molecular subtype, and calculated hazard ratios (HRs) adjusting for demographics, tumor characteristics, treatments, and laboratory values. We tested the performance of established models (Tokuhashi, Bauer, Skeletal Oncology Research Group, New England Spinal Metastases Score) to predict and compare all-cause.

RESULTS

A total of 98 patients surgically treated for breast cancer spine metastases were identified (100% female sex; median age, 56 years [IQR, 36-84 years]). The 1-year probabilities of survival for hormone receptor positive, hormone receptor positive/human epidermal growth factor receptor 2+, human epidermal growth factor receptor 2+, and triple-negative breast cancer were 63% (45 of 71), 83% (10 of 12), 0% (0 of 3), and 12% (1 of 8), respectively ( P < .001). Patients with triple-negative breast cancer had a higher proportion of visceral metastases, brain metastases, and poor physical activity at baseline. Postoperative chemotherapy and endocrine therapy were associated with prolonged survival. The Skeletal Oncology Research Group prognostic model had the highest discrimination (area under the receiver operating characteristic, 0.77 [95% CI, 0.73-0.81]). The performance of all prognostic scores improved when preoperative molecular data and postoperative systemic treatment plans was considered.

CONCLUSION

Spine metastases risk tools were able to predict prognosis at a significantly higher degree after accounting for molecular features which guide treatment response.

An accurate prediction of the origin for bone metastatic cancer using deep learning on digital pathological images

BACKGROUND

Determining the origin of bone metastatic cancer (OBMC) is of great significance to clinical therapeutics. It is challenging for pathologists to determine the OBMC with limited clinical information and bone biopsy.

METHODS

We designed a regional multiple-instance learning algorithm to predict the OBMC based on hematoxylin-eosin (H&E) staining slides alone. We collected 1041 cases from eight different hospitals and labeled 26,431 regions of interest to train the model. The performance of the model was assessed by ten-fold cross validation and external validation. Under the guidance of top3 predictions, we conducted an IHC test on 175 cases of unknown origins to compare the consistency of the results predicted by the model and indicated by the IHC markers. We also applied the model to identify whether there was tumor or not in a region, as well as distinguishing squamous cell carcinoma, adenocarcinoma, and neuroendocrine tumor.

FINDINGS

In the within-cohort, our model achieved a top1-accuracy of 91.35% and a top3-accuracy of 97.75%. In the external cohort, our model displayed a good generalizability with a top3-accuracy of 97.44%. The top1 consistency between the results of the model and the immunohistochemistry markers was 83.90% and the top3 consistency was 94.33%. The model obtained an accuracy of 98.98% to identify whether there was tumor or not and an accuracy of 93.85% to differentiate three types of cancers.

INTERPRETATION

Our model demonstrated good performance to predict the OBMC from routine histology and had great potential for assisting pathologists with determining the OBMC accurately.

FUNDING

National Science Foundation of China (61875102 and 61975089), Natural Science Foundation of Guangdong province (2021A15-15012379 and 2022A1515 012550), Science and Technology Research Program of Shenzhen City (JCYJ20200109110606054 and WDZC20200821141349001), and Tsinghua University Spring Breeze Fund (2020Z99CFZ023).

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.

Development of local injectable, bone-targeting nanocarriers of triptolide for treatment of bone-only metastasis

Triptolide (TP) is known for its diverse pharmacological activities but also its delivery and toxicity issues. This study aimed at exploiting TP's anticancer effects at lower risk of systemic toxicity by developing local-injectable "bone-targeting TP nanoparticle" (TPN) for bone-only metastasis treatment. The lipid/oil-based TPNs decorated with alendronate (ALE) achieved size of 70.4-111.2 nm with good dispersion stability. The drug encapsulation efficiency reached 97 % and drug release profiles were in biphasic, controlled manner lasting for 5 days in medium with serum proteins and calcium. TPNs were more cytotoxic than free TP against MDA-MB-231 breast cancer cells (IC50: 16.40 ± 0.80 nM vs 25.45 ± 1.83 nM, P < 0.05) but less cytotoxic against MC3T3-E1 osteoblasts (P < 0.05). When combined with paclitaxel or docetaxel, low dose TPN (containing 10 nM) significantly increased the effectiveness of the two chemotherapy drugs against MDA-MB-231 (IC50 values decreased from 7.3 nM to 2.5 nM for docetaxel; from 4.6 nM to 1.1 nM), indicating potent chemosensitization effects. Retardation of in vitro cancer cell migration by TPN was also observed in the standard scratch assay. ALE decoration significantly enhanced the TPN affinity for both calcium hydroxyapatite and porcine bone chip models, which led to enhancement in TP retention in the bones up to 8.1-fold versus free drug. Overall, TPN demonstrated good potential as a local-injectable, bone-targeted nanotherapy tailored for eradication of bone-only metastasis at reduced risk of systemic toxicity.

Application of Artificial Intelligence Methods for Imaging of Spinal Metastasis

Spinal metastasis is the most common malignant disease of the spine. Recently, major advances in machine learning and artificial intelligence technology have led to their increased use in oncological imaging. The purpose of this study is to review and summarise the present evidence for artificial intelligence applications in the detection, classification and management of spinal metastasis, along with their potential integration into clinical practice. A systematic, detailed search of the main electronic medical databases was undertaken in concordance with the PRISMA guidelines. A total of 30 articles were retrieved from the database and reviewed. Key findings of current AI applications were compiled and summarised. The main clinical applications of AI techniques include image processing, diagnosis, decision support, treatment assistance and prognostic outcomes. In the realm of spinal oncology, artificial intelligence technologies have achieved relatively good performance and hold immense potential to aid clinicians, including enhancing work efficiency and reducing adverse events. Further research is required to validate the clinical performance of the AI tools and facilitate their integration into routine clinical practice.

Origin and Therapies of Osteosarcoma

Simple Summary

Osteosarcoma is the most common malignant bone tumor in children, with a 5-year survival rate ranging from 70% to 20% depending on the aggressiveness of the disease. The current treatments have not evolved over the past four decades due in part to the genetic complexity of the disease and its heterogeneity. This review will summarize the current knowledge of OS origin, diagnosis and therapies.

Abstract

Osteosarcoma (OS) is the most frequent primary bone tumor, mainly affecting children and young adults. Despite therapeutic advances, the 5-year survival rate is 70% but drastically decreases to 20–30% for poor responders to therapies or for patients with metastasis. No real evolution of the survival rates has been observed for four decades, explained by poor knowledge of the origin, difficulties related to diagnosis and the lack of targeted therapies for this pediatric tumor. This review will describe a non-exhaustive overview of osteosarcoma disease from a clinical and biological point of view, describing the origin, diagnosis and therapies.

Translational Strategies to Target Metastatic Bone Disease

Metastatic bone disease is a common and devastating complication to cancer, confounding treatments and recovery efforts and presenting a significant barrier to de-escalating the adverse outcomes associated with disease progression. Despite significant advances in the field, bone metastases remain presently incurable and contribute heavily to cancer-associated morbidity and mortality. Mechanisms associated with metastatic bone disease perpetuation and paralleled disruption of bone remodeling are highlighted to convey how they provide the foundation for therapeutic targets to stem disease escalation. The focus of this review aims to describe the preclinical modeling and diagnostic evaluation of metastatic bone disease as well as discuss the range of therapeutic modalities used clinically and how they may impact skeletal tissue.

Breast Cancer Induced Bone Osteolysis Prediction Using Temporal Variational Autoencoders

Objective and Impact Statement. We adopt a deep learning model for bone osteolysis prediction on computed tomography (CT) images of murine breast cancer bone metastases. Given the bone CT scans at previous time steps, the model incorporates the bone-cancer interactions learned from the sequential images and generates future CT images. Its ability of predicting the development of bone lesions in cancer-invading bones can assist in assessing the risk of impending fractures and choosing proper treatments in breast cancer bone metastasis. Introduction. Breast cancer often metastasizes to bone, causes osteolytic lesions, and results in skeletal-related events (SREs) including severe pain and even fatal fractures. Although current imaging techniques can detect macroscopic bone lesions, predicting the occurrence and progression of bone lesions remains a challenge. Methods. We adopt a temporal variational autoencoder (T-VAE) model that utilizes a combination of variational autoencoders and long short-term memory networks to predict bone lesion emergence on our micro-CT dataset containing sequential images of murine tibiae. Given the CT scans of murine tibiae at early weeks, our model can learn the distribution of their future states from data. Results. We test our model against other deep learning-based prediction models on the bone lesion progression prediction task. Our model produces much more accurate predictions than existing models under various evaluation metrics. Conclusion. We develop a deep learning framework that can accurately predict and visualize the progression of osteolytic bone lesions. It will assist in planning and evaluating treatment strategies to prevent SREs in breast cancer patients.

Automated detection and segmentation of sclerotic spinal lesions on body CTs using a deep convolutional neural network

PURPOSE

To develop a deep convolutional neural network capable of detecting spinal sclerotic metastases on body CTs.

MATERIALS AND METHODS

Our study was IRB-approved and HIPAA-compliant. Cases of confirmed sclerotic bone metastases in chest, abdomen, and pelvis CTs were identified. Images were manually segmented for 3 classes: background, normal bone, and sclerotic lesion(s). If multiple lesions were present on a slice, all lesions were segmented. A total of 600 images were obtained, with a 90/10 training/testing split. Images were stored as 128 × 128 pixel grayscale and the training dataset underwent a processing pipeline of histogram equalization and data augmentation. We trained our model from scratch on Keras/TensorFlow using an 80/20 training/validation split and a U-Net architecture (64 batch size, 100 epochs, dropout 0.25, initial learning rate 0.0001, sigmoid activation). We also tested our model's true negative and false positive rate with 1104 non-pathologic images. Global sensitivity measured model detection of any lesion on a single image, local sensitivity and positive predictive value (PPV) measured model detection of each lesion on a given image, and local specificity measured the false positive rate in non-pathologic bone.

RESULTS

Dice scores were 0.83 for lesion, 0.96 for non-pathologic bone, and 0.99 for background. Global sensitivity was 95% (57/60), local sensitivity was 92% (89/97), local PPV was 97% (89/92), and local specificity was 87% (958/1104).

CONCLUSION

A deep convolutional neural network has the potential to assist in detecting sclerotic spinal metastases.

Automated detection of skeletal metastasis of lung cancer with bone scans using convolutional nuclear network

Bone scan is widely used for surveying bone metastases caused by various solid tumors. Scintigraphic images are characterized by inferior spatial resolution, bringing a significant challenge to manual analysis of images by nuclear medicine physicians. We present in this work a new framework for automatically classifying scintigraphic images collected from patients clinically diagnosed with lung cancer. The framework consists of data preparation and image classification. In the data preparation stage, data augmentation is used to enlarge the dataset, followed by image fusion and thoracic region extraction. In the image classification stage, we use a self-defined convolutional neural network consisting of feature extraction, feature aggregation, and feature classification sub-networks. The developed multi-class classification network can not only predict whether a bone scan image contains bone metastasis but also tell which subcategory of lung cancer that a bone metastasis metastasized from is present in the image. Experimental evaluations on a set of clinical bone scan images have shown that the proposed multi-class classification network is workable for automated classification of metastatic images, with achieving average scores of 0.7392, 0.7592, 0.7242, and 0.7292 for accuracy, precision, recall, and F-1 score, respectively.

Histomorphometric and microarchitectural analysis of bone in metastatic breast cancer patients

BACKGROUND

Despite widespread use of repeated doses of potent bone-targeting agents (BTA) in oncology patients, relatively little is known about their in vivo effects on bone homeostasis, bone quality, and bone architecture. Traditionally bone quality has been assessed using a trans-iliac bone biopsy with a 7 mm "Bordier" core needle. We examined the feasibility of using a 2 mm "Jamshidi™" core needle as a more practical and less invasive technique.

METHODS

Patients with metastatic breast cancer on BTAs were divided according to the extent of bone metastases. They were given 2 courses of tetracycline labeling and then underwent a posterior trans-iliac trephine biopsy and bone marrow aspirate. Samples were analyzed for the extent of tumor invasion and parameters of bone turnover and bone formation by histomorphometry.

RESULTS

Twelve patients were accrued, 1 had no bone metastases, 3 had limited bone metastases (LSM) (<3 lesions) and 7 had extensive bone metastases (ESM) (>3 lesions). Most of the primary tumors were estrogen receptor (ER)/progesterone receptor (PR) positive. The procedure was well tolerated. The sample quality was sufficient to analyze bone trabecular structure and bone turnover by histomorphometry in 11 out of 12 patients. There was a good correlation between imaging data and morphometric analysis of tumor invasion. Patients with no evidence or minimal bone metastases had no evidence of tumor invasion. Most had suppressed bone turnover and no detectable bone formation when treated with BTA. In contrast, 6 out of 7 patients with extensive bone invasion by imaging and evidence of tumor cells in the marrow had intense osteoclastic activity as measured by the number of osteoclasts. Of these 7 patients with ESM, 6 were treated with BTA with 5 showing resistance to BTA as demonstrated by the high number of osteoclasts present. 3 of these 6 patients had active bone formation. Based on osteoblast activity and bone formation, 3 out of 6 patients with ESM responded to BTA compared to all 3 with LSM. Compared to untreated patients, all patients treated with BTA showed a trend towards suppression of bone formation, as measured by tetracycline labelling. There was also a trend towards a significant difference between ESM and LSM treated with BTA, highly suggestive of resistance although limited by the small sample size.

DISCUSSION

Our results indicate that trans-iliac bone biopsy using a 2 mm trephine shows excellent correlation between imaging assessment of tumor invasion and tumor burden by morphometric analysis of bone tissues. In addition, our approach provides additional mechanistic information on therapeutic response to BTA supporting the current clinical understanding that the majority of patients with extensive bone involvement eventually fail to suppress bone turnover (Petrut B, et al. 2008). This suggests that antiresorptive therapies become less effective as disease progresses.

Moderate tibial loading and treadmill running, but not overloading, protect adult murine bone from destruction by metastasized breast cancer

Osteolytic bone lesions, which develop in many metastatic breast cancer patients, impair bone integrity and lead to adverse skeletal related events that are difficult to treat and sometimes fatal. Moderate mechanical loading has been shown to suppress osteolysis in young mice with breast cancer. In this study, we aimed to investigate the dose-dependent effects of mechanical loading on protecting the integrity of adult skeletons with breast cancer. Localized tibial loading and aerobic treadmill running with three levels of varying intensity were tested in a syngeneic mammary tumor bone metastasis model. Adult C57BL/6J female mice (14-week-old, N = 88 mice) received intra-tibial injections of Py8119 triple-negative murine breast cancer cells or PBS and underwent 4 to 5 weeks of exercise or acted as sedentary/non-loaded controls. The bone structure was monitored longitudinally with weekly in vivo micro-computed tomography imaging, while the cellular responses in bone and marrow were examined using immunohistochemistry. Moderate treadmill running (16 m/min, 50 min/day, 5 days/week, and 5 weeks) and tibial loading (4.5 N, 630 με, 4 Hz, 300 cycles/day, 5 days/week, and 4 weeks) suppressed tumor-induced bone destruction, as evaluated by full-thickness perforation of tibial cortex and the volume of osteolytic lesions in the cortex. In contrast, tibial loading at higher magnitude (8 N, 1100 με) induced woven bone and accelerated bone destruction, compared with the non-loaded controls. The three exercise regimens differentially affected osteocyte apoptosis, osteocyte hypoxia, osteoclast activity, bone marrow vasculature, and tumor proliferation. In conclusion, the relationship between exercise intensity and the risk of breast cancer-induced osteolysis was found to follow a J-shaped curve in a preclinical model, suggesting the need to optimize exercise parameters in order to harness the skeletal benefits of exercise in metastatic breast cancers.

The Role of a Navigational Radiofrequency Ablation Device and Concurrent Vertebral Augmentation for Treatment of Difficult-to-Reach Spinal Metastases

AIMS

The purpose of this study was to assess the effectiveness of a navigational radiofrequency ablation device with concurrent vertebral augmentation in the treatment of posterior vertebral body metastatic lesions, which are technically difficult to access. Primary outcomes of the study were evaluation of pain palliation and radiologic assessment of local tumor control.

MATERIALS AND METHODS

Thirty-five patients with 41 vertebral spinal metastases involving the posterior vertebral body underwent computed tomography-guided percutaneous targeted radiofrequency ablation, with a navigational radiofrequency ablation device, associated with vertebral augmentation. Twenty-one patients (60%) had 1 or 2 metastatic lesions (Group A) and fourteen (40%) patients had multiple (>2) vertebral lesions (Group B). Changes in pain severity were evaluated by visual analog scale (VAS). Metastatic lesions were evaluated in terms of radiological local control.

RESULTS

The procedure was technically successful in all the treated vertebrae. Among the symptomatic patients, the mean VAS score dropped from 5.7 (95% CI 4.9-6.5) before tRFA and to 0.9 (95% CI 0.4-1.3) after tRFA (p < 0.001). The mean decrease in VAS score between baseline and one week follow up was 4.8 (95% CI 4.2-5.4). VAS decrease over time between one week and one year following radiofrequency ablation was similar, suggesting that pain relief was immediate and durable. Neither patients with 1-2 vertebral metastases, nor those with multiple lesions, showed radiological signs of local progression or recurrence of the tumor in the index vertebrae during a median follow up of 19 months (4-46 months) and 10 months (4-37 months), respectively.

CONCLUSION

Treatment of spinal metastases with a navigational radiofrequency ablation device and vertebral augmentation can be used to obtain local tumor control with immediate and durable pain relief, providing effective treatment in the multimodality management of difficult-to-reach spinal metastases.

Prognosis of Patients With Early Breast Cancer Receiving 5 Years vs 2 Years of Adjuvant Bisphosphonate Treatment: A Phase 3 Randomized Clinical Trial

Importance

Bisphosphonate treatment in patients with early breast cancer has become part of care, but the optimal treatment duration is still unclear.

Objective

To compare 2 vs 5 years of zoledronate treatment following adjuvant chemotherapy in patients with early breast cancer.

Design, Setting, and Participants

The SUCCESS A phase 3 multicenter randomized open-label clinical trial with a 2 × 2 factorial design enrolled 3754 patients from September 21, 2005, to March 12, 2007 (last patient out, May 7, 2014). Final data analysis was conducted from September 2019 to October 2020. In 250 German study centers, patients were eligible for participation in the SUCCESS A trial if they had either node-positive or high-risk node-negative (defined as at least 1 of the following: tumor size ≥ pT2, histologic grade 3, negative hormone receptor status, or age ≤35 years) primary invasive breast cancer.

Interventions

Patients were first randomized to adjuvant chemotherapy with 3 cycles of fluorouracil, epirubicin, and cyclophosphamide followed by 3 cycles of docetaxel with or without gemcitabine (not presented in this report). After chemotherapy, patients underwent a second randomization of 5 years of zoledronate treatment (4 mg intravenously every 3 months for 2 years, followed by 4 mg intravenously every 6 months for 3 years) vs 2 years of zoledronate treatment (4 mg intravenously every 3 months for 2 years).

Main Outcomes and Measures

The primary end point of the study was disease-free survival; secondary end points were overall survival, distant disease-free survival, and the incidence of skeletal-related adverse events. Survival times were measured from 2 years after the start of zoledronate treatment (landmark analysis).

Results

Overall, data on 2987 patients were available for analysis; median age was 53 (range, 21-86) years. Disease-free survival, overall survival, and distant disease-free survival did not differ significantly between the 2 treatment arms (5 vs 2 years) as shown by adjusted multivariable Cox proportional hazards regression models (disease-free survival: hazard ratio [HR], 0.97; 95% CI, 0.75-1.25; P = .81; overall survival: HR, 0.98; 95% CI, 0.67-1.42; P = .90; distant disease-free survival: HR, 0.87; 95% CI, 0.65-1.18; P = .38). Adverse events were observed more often in the 5-year (46.2%) vs 2-year (27.2%) zoledronate treatment arm, which was particularly true for the skeletal-related events bone pain (5 years, 8.3% vs 2 years, 3.7%) and arthralgia (5 years, 5.1% vs 2 years, 3.1%).

Conclusions and Relevance

The results of this phase 3 randomized clinical trial indicate that extending the zoledronate treatment beyond 2 years does not improve the prognosis of high-risk patients with early breast cancer receiving chemotherapy, suggesting that the currently recommended bisphosphonate treatment duration of 3 to 5 years could be reduced.

Trial Registration

ClinicalTrials.gov Identifier: NCT02181101.

Perceptions around bone-modifying agent use in patients with bone metastases from breast and castration resistant prostate cancer: a patient survey

BACKGROUND

Optimal use of bone-modifying agent (BMA) therapy in patients with bone metastases from breast and castrate-resistant prostate cancer (CRPC) is evolving.

METHODS

Patients receiving BMA for bone metastases from breast or CRPC were surveyed. Information was collected on patient and disease characteristics, BMA treatments and perceptions regarding BMA benefits and side effects. Interest in participation in trials of de-escalated BMA therapy was also gauged.

RESULTS

Of 220 patients contacted, 172 eligible patients responded (response rate 78%). Median age was 67 (range: 21-91); 137 (80%) had breast cancer and 35 (20%) CRPC. Symptomatic skeletal events (SSEs) occurred prior to starting BMAs in 61% (84/137) of breast and 48% (17/35) of CRPC patients. Among breast cancer patients, 47, 33 and 13% received zoledronate, pamidronate and denosumab, respectively. Eighty-five percent (30/35) of CRPC patients received denosumab. De-escalation of therapy was more common among breast cancer patients. Although most patients correctly reported the goals of BMA therapy were to "help stop fractures" (62%) and "[improve] quality of life" (63%), 46.5% felt it prolonged survival and 54% felt it reduced bone progression. Most respondents (102/129, 79%) were comfortable with de-escalating to 6-monthly treatment after 2 years of BMA therapy. Patients considered the most important endpoints of de-escalation studies to be "stability of bone metastases" (45%), "quality of life" (22%) and "SSE rates" (14%).

CONCLUSION

Twelve weekly BMA was more common in breast than in prostate cancer. There remain misconceptions about the benefits of BMAs, highlighting potential gaps in patient education. Patients were interested in further BMA de-escalation after 2 years of prior BMA and provided study endpoints that were most important to them.

Cost-Effectiveness Analysis of 12-Versus 4-Weekly Administration of Bone-Targeted Agents in Patients with Bone Metastases from Breast and Castration-Resistant Prostate Cancer

A cost–utility analysis was performed based on the Rethinking Clinical Trials (REaCT) bone-targeted agents (BTA) clinical trial that compared 12-weekly (once every 12 weeks) (n = 130) versus 4-weekly (once every 4 weeks) (n = 133) BTA dosing for metastatic breast and castration-resistant prostate (CRPC) cancer. Using a decision tree model, we calculated treatment and symptomatic skeletal event (SSE) costs as well as quality-adjusted life-years (QALYs) for each treatment option. Deterministic and probabilistic sensitivity analyses were performed to assess the robustness of the study findings. The total cost of BTA treatment in Canadian dollars (C$) and estimated QALYs was C$8965.03 and 0.605 QALY in the 4-weekly group versus C$5669.95 and 0.612 QALY in the 12-weekly group, respectively. De-escalation from 4-weekly to 12-weekly BTA reduces cost (C$3293.75) and improves QALYs by 0.008 unit, suggesting that 12-weekly BTA dominates 4-weekly BTA in breast and CRPC patients with bone metastases. Sensitivity analysis suggests high levels of uncertainty in the cost-effectiveness findings. De-escalation of bone-targeted agents is cost-effective from the Canadian public payer’s perspective.

A Review of Literature on Updates of Bisphosphonates Administration, Cancer Biomarkers for Bisphosphonate Therapy, and Bisphosphonate-related Osteonecrosis of the Jaw in Breast Cancer

Context: The emergence of bone health maintenance in breast cancer patients is known as an indispensable aspect in survival and morbidity improvement; therefore, bisphosphonates play a substantial role in the prevention/delaying of cancer treatment induced bone loss and skeletal-related events (SREs) in these patients, although this drug can cause necrosis of the jaw. In this article, we aimed at summarizing updated evidence on bisphosphonates administration, biomarkers representative of the efficacy of bisphosphonate therapy, and bisphosphonate-related osteonecrosis of the jaw (BRONJ) affection in patients involved in breast cancer. Methods: Associated published articles were searched for in EMBASE, MEDLINE, CDSR, PubMed, Google Scholar, and CINAHL, using the following keywords or, in the case of PubMed database, medical subject headings (MeSH): ‘Diphosphonate’, ‘osteonecrosis’, ‘breast cancer’, and ‘biomarker’ in the abstract or title, and was limited by "clinical trials, meta-analysis and randomized controlled trial” published in English language from 2015 to 2020-09-15. Results: Bisphosphonates depicted remarkable advantages in improving SREs, skeletal morbidity rate (SMR), survival rate, and treatment-emergent adverse events in breast cancer patients in almost all aspects of breast cancer therapy, from adjuvant therapy for the early stage breast cancer to bone metastatic breast cancer (BMBC). The identification of breast cancer biomarkers that are capable of reflecting the outcomes of bisphosphonates therapy is a highly advantageous aid in the optimal utilization of these drugs. Breast cancer biomarkers such as MAF, DOCK4, CD73, TLR9, and CAPG/GIPC1 composite illustrated a significant correlation with bisphosphonates administration. Medication-related osteonecrosis of the jaw (MRONJ) stands out as the most hazardous adverse event of the bisphosphonates with a rationally high incidence among breast cancer patients, which requires cautious prescription of bisphosphonates as well as regular dental health counseling for being prevented. Conclusions: Bisphosphonates are great weapons in the arsenal of breast cancer treatment and, therefore, comprehensive studying of their features leads to the optimal and safe administration of them. Unfortunately, as this procedure can cause necrosis of the jaw, dental procedures should be performed in these patients before starting bisphosphonate treatment.

Real-world practice patterns and attitudes towards de-escalation of bone-modifying agents in patients with bone metastases from breast and prostate cancer: A physician survey

•

Questions around optimal use of bone-modifying agents (BMAs) still exist.

•

Most physicians are de-escalating BMAs in patients with metastatic breast cancer.

•

Practice varies according to patient insurance coverage.

•

There is interest performing further trials of de-escalation especially after 2 years of treatment.

Background

There remain questions around the optimal use of bone-modifying agents (BMAs) in patients with bone metastases from breast and castration-resistant prostate cancer (CRPC). A physician survey was performed to identify current practices, as well as perceptions around long-term BMA use, BMA de-escalation, and further BMA de-escalation after 2 years of use.

Methods

Canadian oncologists treating breast cancer or CRPC were surveyed via an anonymized online survey. The survey collected physician demographics, current practice patterns, perception on risk of symptomatic skeletal events (SSE) and BMA-associated toxicities, and attitudes towards further de-escalation of BMAs after 2 years of treatment.

Results

A total of 334 physicians in Canada were contacted, of which 295 were eligible on initial screening, and 65 completed the survey (response rate 22%): 35 treated breast cancer, 25 treated prostate cancer and 5 treated both. The most common BMA regimens in patients with no limitation in drug coverage were denosumab q4wks for 3–4 months followed by a de-escalation to q12wks (breast cancer) and denosumab q4wks (prostate cancer). In patients with provincial health coverage only the common choices were zoledronate q4wks for 3–4 months followed by de-escalation to q12wks (breast cancer) and denosumab q4wks (prostate cancer). There was equipoise regarding the benefit of continuing BMA beyond 2 years and interest in further trials of de-escalation of BMA in both breast and prostate cancer. The most favored alternative primary study endpoints to SSE were BMA toxicity (67.2%), pain (46.9%), and physical function (48.4%).

Conclusion

Despite their extensive use and costs, questions around optimal use of BMAs still exist. Practice varies according to patient insurance coverage. However, most physicians are de-escalating BMAs. There is interest amongst clinicians in performing trials of de-escalation, especially after 2 years of treatment.

Circulating Osteocalcin-Positive Cells as a Novel Diagnostic Biomarker for Bone Metastasis in Breast Cancer Patients

Current diagnosis of bone metastasis (BM) in breast cancer relies on structural changes of bone that occur only in the advanced stage. A sensitive biomarker for detecting early progression of bone metastasis is urgently required. We performed clinical and preclinical studies to investigate diagnostic value of circulating osteocalcin-positive cells (cOC) in breast cancer bone metastasis. Metastatic breast cancer patients (n = 92) with or without bone metastasis (ie, BM⁺ or BM^- ) were enrolled, and cOC were measured at enrollment. Patients were followed up for bone metastasis progression for 18 months. BM⁺ patients (n = 59) were divided into progressive (PD) or stable disease (SD) groups, based on imaging studies at the end of the 18-month study. The PD group had higher baseline cOC compared with the SD group. Furthermore, higher cOC resulted in reduced BM progression-free survival. Three patients in the BM^- group (n = 33) developed new BM during the 18-month study, and these patients had a higher level of baseline cOC compared with the remaining BM^- patients. In murine preclinical studies, cOC increased at early time points when micro-metastases were evident only by histology but undetectable by bioluminescence imaging. Also, cOC levels predicted the progression of BM and correlated significantly with BM tumor burden. cOC increased in the early phase of breast cancer BM and can predict BM progression, supporting cOC as a potential novel biomarker. © 2020 American Society for Bone and Mineral Research.

Practical update for the use of bone-targeted agents in patients with bone metastases from metastatic breast cancer or castration-resistant prostate cancer

Bone metastases are a significant source of morbidity and mortality for patients with breast and prostate cancer. In this review, we discuss key practical themes regarding the use of bone-targeted agents (btas) such as bisphosphonates and denosumab for managing bony metastatic disease. The btas both delay the onset and reduce the incidence of skeletal-related events (sres), defined as any or all of a need for radiation therapy or surgery to bone, pathologic fracture, spinal cord compression, or hypercalcemia of malignancy. They have more modest benefits for pain and other quality-of-life measures. Regardless of the benefits of btas, it should always be remembered that the palliative management of metastatic bone disease is multimodal and multidisciplinary. The collaboration of all disciplines is essential for optimal patient care. Special consideration is given to these key questions: ■ What are btas, and what is their efficacy?■ What are their common toxicities?■ When should they be initiated?■ How do we choose the appropriate bta?■ What is the appropriate dose, schedule, and duration of btas?

Long-term impact of bone-modifying agents for the treatment of bone metastases: a systematic review

PURPOSE

Bone-modifying agents (BMAs) for bone metastases are commonly prescribed for many years even though randomized clinical trials are only 1-2 years in duration. A systematic review on the risk-benefit of BMA use for > 2 years in breast cancer or castrate-resistant prostate cancer was conducted.

METHODS

MEDLINE, Embase, and Cochrane databases were searched (1970-February 2019) for randomized and observational studies, and case series reporting on BMA efficacy (skeletal-related events and quality of life) and toxicity (osteonecrosis of the jaw, renal impairment, hypocalcemia, and atypical femoral fractures) beyond 2 years.

RESULTS

Of 2107 citations, 64 studies were identified. Three prospective and 9 retrospective studies were eligible. Data beyond 2 years was limited to subgroup analyses in all studies. Only one study (n = 181) reported skeletal-related event rates based on bisphosphonate exposure, with decreased rates from 27.6% (0-24 months) to 15.5% (> 24 months). None reported on quality of life. All 12 studies (denosumab (n = 948), zoledronate (n = 1036), pamidronate (n = 163), pamidronate-zoledronate (n = 522), ibandronate (n = 118)) reported ≥ 1 toxicity outcome. Seven bisphosphonate studies (n = 1077) and one denosumab study (n = 948) reported on osteonecrosis of the jaw. Across three studies (n = 1236), osteonecrosis of the jaw incidence ranged from 1 to 4% in the first 2 years to 3.8-18% after 2 years. Clinically significant hypocalcemia ranged from 1 to 2%. Severe renal function decline was ≤ 3%. Atypical femoral fractures were rare.

CONCLUSIONS

Evidence informing the use of BMA beyond 2 years is heterogeneous and based on retrospective analysis. Prospective randomized studies with greater emphasis on quality of life are needed.

PROSPERO REGISTRATION NUMBER

CRD42019126813.

uPAR antibody (huATN-658) and Zometa reduce breast cancer growth and skeletal lesions

Urokinase plasminogen activator receptor (uPAR) is implicated in tumor growth and metastasis due to its ability to activate latent growth factors, proteases, and different oncogenic signaling pathways upon binding to different ligands. Elevated uPAR expression is correlated with the increased aggressiveness of cancer cells, which led to its credentialing as an attractive diagnostic and therapeutic target in advanced solid cancer. Here, we examine the antitumor effects of a humanized anti-uPAR antibody (huATN-658) alone and in combination with the approved bisphosphonate Zometa (Zoledronic acid) on skeletal lesion through a series of studies in vitro and in vivo. Treatment with huATN-658 or Zometa alone significantly decreased human MDA-MB-231 cell proliferation and invasion in vitro, effects which were more pronounced when huATN-658 was combined with Zometa. In vivo studies demonstrated that huATN-658 treatment significantly reduced MDA-MB-231 primary tumor growth compared with controls. In a model of breast tumor-induced bone disease, huATN-658 and Zometa were equally effective in reducing skeletal lesions. The skeletal lesions were significantly reduced in animals receiving the combination of huATN-658 + Zometa compared with monotherapy treatment. These effects were due to a significant decrease in osteoclastic activity and tumor cell proliferation in the combination treatment group. Transcriptome analysis revealed that combination treatment significantly changes the expression of genes from signaling pathways implicated in tumor progression and bone remodeling. Results from these studies provide a rationale for the continued development of huATN-658 as a monotherapy and in combination with currently approved agents such as Zometa in patients with metastatic breast cancer.

Is De-escalated Bisphosphonates Therapy a Suitable Alternative to Standard Dosing in Malignant Tumor Patients With Bone Metastases: A Systematic Review and Meta-Analysis

Background: Previous studies have preliminarily identified the non-inferior efficacy for reducing skeletal-related event (SRE) rates between de-escalated (Q12w) and standard (Q3-4w) bone-targeting agents therapy in malignant tumor patients with bone metastases. In this study, we aim to make further efforts to analyze whether the de-escalated bisphosphonates (BPs) strategy is a suitable option by comprehensively retrieving and synthesizing state-of-the-art evidence. Methods: An extensive electronic search for randomized controlled trials (RCTs) comparing a BPs standard strategy with the de-escalated one in patients with bone metastases was performed up to June 2018. Outcomes of interest were general and found individual types of SRE, skeletal morbidity rate (SMR), bone pain, bone turnover biomarkers and adverse events (AEs). Continuous and dichotomous outcomes were summarized by the weighted mean difference (WMD) and risk ratio (RR), respectively, with 95% confidence intervals (CIs). Results: A total of eight studies, representing six unique trials (involving 3114 patients), were included. Pooled results indicated comparable efficacy on general SRE (RR 0.99, 95% CI 0.87-1.12; P = 0.86; I 2 = 0%) and SMR (WMD 0.00, 95% CI -0.02 -0.03; P = 0.81; I 2 = 0%). However, the rate of surgery involving bones was significantly higher in de-escalated group than standard group (RR 1.92, 95% CI 1.17-3.15; P = 0.01; I 2 = 0%) among individual types of SRE. Several trials also demonstrated increased levels of C-terminal or N-terminal telopeptide in de-escalated group. Meta-analyses for gastrointestinal disorders, dizziness and back pain showed significant reductions by 27% (RR 0.73, 95% CI 0.57-0.94; P = 0.01; I 2 = 0%), 48% (RR 0.52 95% CI 0.32-0.86; P = 0.01; I 2 = 0%), and 29% (RR 0.71, 0.51-0.99; P = 0.04; I 2 = 0%), respectively, compared to the standard therapy. Conclusion: For malignant tumor patients with bone metastases, a de-escalated BPs strategy is proved to have a better safety profile compared to standard dosing. Although the efficacy is generally comparable on SRE and SMR between the two dosing regimens, trials with long duration and large sample sizes are still warranted to make a solid judgment.

Incidence of skeletal-related events in patients with breast or prostate cancer-induced bone metastasis or multiple myeloma: A 12-year longitudinal nationwide healthcare database study

BACKGROUND

This study examined the incidence of skeletal-related events (SRE) among patients with breast cancer (BC)- or prostate cancer (PC)-induced bone metastasis or multiple myeloma (MM) based on a population-based, 12-year healthcare database.

METHODS

Patients aged ≥18 years with bone metastasis from BC or PC or with MM between 2004 and 2015 were included. SRE was defined as pathologic fracture, spinal cord compression, radiation, or surgery to bone. Patients were followed-up from the initial diagnosis of bone metastasis (for those with BC or PC) or MM until SRE occurrence. To estimate multiple SREs, we applied a 21-day time window to ensure that subsequent SREs occurred independently from the previous event. We calculated the incidence and 95% confidence intervals (CIs), stratified according to the previous SRE history.

RESULTS

Our cohort included 53,231 patients, including 23,811 with BC, 19,170 with PC, and 10,250 with MM. The incidence of multiple SREs in the 21-day time window was 1.03 (95% CI = 1.01-1.05) in patients with previous SRE history and 0.19 (95% CI = 0.19-0.20) in those without. The cumulative SRE incidences were 47%, 31.4%, and 38.0% in BC, PC, and MM patients.

CONCLUSION

The incidences of multiple SREs in BC- or PC-induced bone metastasis or MM in this 12-year South Korean cohort were slightly higher than those in European countries. Our study provided real-world evidence that patients with BC- or PC-induced bone metastasis or MM are at high risk of SRE.

De-escalation of bone-modifying agents in patients with bone metastases from breast cancer: a systematic review and meta-analysis

PURPOSE

Bone-modifying agents (BMAs) such as bisphosphonates and denosumab are usually administered every 4 weeks (standard) in patients with bone metastases from breast cancer to prevent skeletal-related events (SREs). Recent randomized controlled trials suggest every 12-week (de-escalated) dosing interval may be non-inferior. The objective of this systematic review and meta-analysis was to compare the efficacy and harms of standard with de-escalated administration of BMA's in patients with bone metastases from breast cancer.

METHODS

We searched Medline, PubMed, and the Cochrane Register of Controlled Trials from 1947 to March 14, 2018 and conference abstracts from (2014-March 14, 2018) for randomized clinical trials comparing every 4-week and every 12-week dosing interval of bone-modifying agents. Using PRISMA guidelines, meta-analyses were performed using random-effects models, with findings reported as risk ratios with 95% confidence intervals (CI).

RESULTS

From a total of 1311 citations, we identified 8 full-text articles and 1 abstract comprising data from 5 completed randomized clinical trials (n = 1807). Zoledronate administration every 12 weeks compared to every 4 weeks produced a summary risk ratio of 1.05 (95% CI 0.88-1.25) for patients with ≥ 1 on-study SRE indicating similar efficacy. These results did not differ whether patients had received prior intravenous bisphosphonate. De-escalation was associated with a non-statistically significant lower risk of increased creatinine (summary risk ratio 0.41 [95% CI 0.15-1.16]). Currently, there are insufficient data for pamidronate and denosumab de-escalation.

CONCLUSIONS

These data are supportive of de-escalation of zoledronate from onset for patients with bone metastases from breast cancer.

Efficacy and safety of de-escalation bone- modifying agents for cancer patients with bone metastases: a systematic review and meta-analysis

Background

Compared with application of bone-modifying agents (BMAs) every 4 weeks, it is unclear whether 12-weekly de-escalated therapy can be used as a substitute strategy.

Methods

A systematic search of PubMed, EMBASE, and the Cochrane Register of Controlled Trials until November 22, 2017, was performed. Randomized controlled trials (RCTs) were included to assess skeletal-related event (SRE) rates, adverse events, and bone turnover biomarkers, comparing 12-weekly de-escalated treatments with standard 4-weekly dosage regimens. Risk ratios (RRs) with 95% CIs were pooled in fixed-effect meta-analyses.

Results

A total of eight citations were eligible comprising 2,878 patients: zoledronate (three studies, 2,650 patients), pamidronate (two studies, 68 patients), and denosumab (three studies, 160 patients). Summary RR (0.98; 95% CI 0.87–1.12; P=0.82) for SRE rates between de-escalated and standard arms was produced when seven low risk of bias trials (695 patients) were pooled, and results without statistical significance also appeared in the analysis of adverse events and bone turnover biomarkers. Due to the limited sample size and methodological differences, the data for skeletal morbidity rates (SMRs), time to first SRE, serum C-telopeptide (sCTx) levels, and hypocalcemia were not combined, but systematic review still obtained similar indistinguishableness.

Conclusion

In this meta-analysis of randomized clinical trials, the results “appeared” to show non-inferiority of the 12-weekly treatment. Due to the difference in available data, the results for bisphosphonates are more solid than for the receptor activator of nuclear factor-κB ligand (RANKL) antibodies.

Single vs multiple fraction palliative radiotherapy for uncomplicated painful bone metastases treated at University of Malaya Medical Centre: A single institutional Malaysian experience

INTRODUCTION

This study was conducted to compare pain response between single and multiple fraction palliative radiotherapy and to describe prognostic factors affecting treatment response in University of Malaya Medical Centre (UMMC).

METHODS

The case records of 162 patients with uncomplicated painful bone metastases treated with palliative radiotherapy from 2006 to 2014 were analyzed. Treatment outcomes were pain score response, analgesic score response, response according to International Consensus Endpoints (complete response and overall response) at 4, 12, and 24 weeks, retreatment rate, symptomatic skeletal events (SSEs), and prognostic factors.

RESULTS

At 24 weeks, pain score response for single and multiple fraction group was 82.3% and 88.5%, analgesic score response was 54.8% and 61.5%, and overall response according to International Consensus Endpoint was 61.3% and 67.7%, respectively. There was no statistically significant difference in treatment response between the 2 treatment groups for all endpoints. ECOG (<2 vs ≥2: aOR 3.405, 95% CI 1.708-6.790, P = .001) and primary breast and prostate (breast vs others: aOR 5.231, 95% CI 1.973-13.869, P = .001; prostate vs others: aOR 5.522, 95% CI 1.493-20.420, P = .01) were significant variables on multivariate analysis.

CONCLUSION

Single fraction radiotherapy is as effective as multiple fraction radiotherapy for the palliation of uncomplicated bone metastases.

Physicians' preferences for bone metastases treatments in France, Germany and the United Kingdom

BACKGROUND

Several bone-targeted agents (BTAs) are available for preventing skeletal-related events (SREs), but they vary in terms of efficacy, safety and mode of administration. This study assessed data on European physicians' treatment preferences for preventing SREs in patients with bone metastases from solid tumours.

METHODS

Physicians completed a web-based discrete-choice experiment survey of 10 choices between pairs of profiles of hypothetical BTAs for a putative patient. Each profile included five attributes within a pre-defined range (primarily based on existing BTAs' prescribing information): time (months) until the first SRE; time (months) until worsening of pain; annual risk of osteonecrosis of the jaw (ONJ); annual risk of renal impairment; and mode of administration. Choice questions were developed using an experimental design with known statistical properties. A separate main-effects random parameters logit model was estimated for each country and provided the relative preference for the treatment attributes in the study.

RESULTS

A total of 191 physicians in France, 192 physicians in Germany, and 197 physicians in the United Kingdom completed the survey. In France and the United Kingdom, time until the first SRE and risk of renal impairment were the most important attributes; in Germany, time until the first SRE and delay in worsening of pain were the most important. In all countries, a 120-min infusion every 4 weeks was the least preferred mode of administration (p < 0.05) and the annual risk of ONJ was judged to be the least important attribute.

CONCLUSIONS

When making treatment decisions regarding the choice of BTA, delaying the onset of SREs/worsening of pain and reducing the risk of renal impairment are the primary objectives for physicians.

Understanding the Progression of Bone Metastases to Identify Novel Therapeutic Targets

Bone is one of the most preferential target site for cancer metastases, particularly for prostate, breast, kidney, lung and thyroid primary tumours. Indeed, numerous chemical signals and growth factors produced by the bone microenvironment constitute factors promoting cancer cell invasion and aggression. After reviewing the different theories proposed to provide mechanism for metastatic progression, we report on the gene expression profile of bone-seeking cancer cells. We also discuss the cross-talk between the bone microenvironment and invading cells, which impacts on the tumour actions on surrounding bone tissue. Lastly, we detail therapies for bone metastases. Due to poor prognosis for patients, the strategies mainly aim at reducing the impact of skeletal-related events on patients' quality of life. However, recent advances have led to a better understanding of molecular mechanisms underlying bone metastases progression, and therefore of novel therapeutic targets.

Effects on bone resorption markers of continuing pamidronate or switching to zoledronic acid in patients with high risk bone metastases from breast cancer

Background

Switching patients who remain at high risk of skeletal related events (SREs) despite pamidronate to the more potent bisphosphonate zoledronate, may be an effective treatment strategy. As part of a previously reported clinic study in this setting, we evaluated whether biomarkers for bone resorption, such as Bone-Specific Alkaline Phosphatase (BSAP), bone sialoprotein (BSP), and N-terminal telopeptide (NTX) correlated with subsequent SRE risk.

Methods

Breast cancer patients who remained at high risk of SREs despite at least 3 months of q.3–4 weekly pamidronate were randomized to either continue on pamidronate or to switch to zoledronate (4 mg) once every 4 weeks for 12-weeks. High risk bone metastases were defined by either: occurrence of a prior SRE, bone pain, radiologic progression of bone metastases and/or serum C-terminal telopeptide (CTx) levels > 400 ng/L despite pamidronate use. Serum samples were collected at baseline and weeks 1, 4, 8 and 12 (CTx and BSAP) and baseline and week 12 (NTx and BSP), and all putative biomarkers were measured by ELISA. Follow up was extended to 2 years post trial entry for risk of subsequent SREs. The Kaplan-Meier method was used to estimate time-to-event outcomes. Generalized estimating equations (GEE) were used to evaluate if laboratory values over time or the change in laboratory values from baseline were associated with having a SRE within the time frame of this study.

Results

From March 2012 to May 2014, 76 patients were screened, with 73 eligible for enrolment. All 73 patients were available for biochemical analysis, with 35 patients receiving pamidronate and 38 patients receiving zoledronate. The GEE analysis found that no laboratory value was associated with having a subsequent SRE. Interaction between visit and laboratory values was also investigated, but no interaction effect was statistically significant. Only increased number of lines of prior hormonal treatment was associated with subsequent SRE risk.

Conclusion

Our analysis failed to find any association between serum BSAP, BSP, CTx or NTx levels and subsequent SRE risk in this cohort of patients. This lack of correlation between serum biomarkers and clinical outcomes could be due to influences of prior bisphosphonate treatment or presence of extra-osseous metastases in a significant proportion of enrolled patients. As such, caution should be used in biomarker interpretation and use to direct decision making regarding SRE risk for high risk patients in this setting.

Quantitative contrast-enhanced CT attenuation evaluation of osseous metastases following chemotherapy

PURPOSE

Osseous metastases often undergo an osteoblastic healing response following chemotherapy. The purpose of our study was to demonstrate the quantitative CT changes in attenuation of osseous metastases before and after chemotherapy.

MATERIALS AND METHODS

Our study was IRB approved and HIPAA compliant. Our cohort consisted of 86 consecutive cancer patients with contrast-enhanced CTs before and 14 ± 2 (12-25) months after initiation of chemotherapy (60 ± 11 years, 36 males, 50 females). The average and maximum metastasis attenuations were measured in Hounsfield units (HU) by two readers. Treatment effects were assessed using paired t-tests and Fisher exact tests. Intraclass correlation coefficients (ICCs) were calculated. Patient records were reviewed to determine the patient's clinical status (worse, unchanged, or improved) at the time of follow-up CT.

RESULTS

The distribution of lesion types was as follows: lytic (30/86, 35%), blastic (43/86, 50%), and mixed lytic-blastic (13/86, 15%). There was a significant increase in average and maximum CT attenuation of metastases following chemotherapy for all patients, which remained statistically significant when stratified by lesion type, clinical status (worsening or improving/stable), cancer type (breast, lung), and radiation therapy (P < 0.05). In a subgroup of patients whose osseous metastases decreased in average attenuation (14/86, 16%), more patients had a worse clinical status (11/14, 79%) (P = 0.02). ICC was almost perfect for average attenuation and substantial for maximum attenuation.

CONCLUSION

Quantitative assessment of osseous metastatic disease using CT attenuation measurements demonstrated a statistically significant increase in attenuation more than 12 months after initiation of chemotherapy.

Overcoming immunosuppression in bone metastases

Bone metastases are present in up to 70% of advanced prostate and breast cancers and occur at significant rates in a variety of other cancers. Bone metastases can be associated with significant morbidity. The establishment of bone metastasis activates several immunosuppressive mechanisms. Hence, understanding the tumor-bone microenvironment is crucial to inform the development of novel therapies. This review describes the current standard of care for patients with bone metastatic disease and novel treatment options targeting the microenvironment. Treatments reviewed include immunotherapies, cryoablation, and targeted therapies. Combinatorial treatment strategies including targeted therapies and immunotherapies show promise in pre-clinical and clinical studies to overcome the suppressive environment and improve treatment of bone metastases.

Validity of Osteoprotegerin and Receptor Activator of NF-κB Ligand for the Detection of Bone Metastasis in Breast Cancer

Osteoprotegerin (OPG) is a robust antiresorptive molecule that acts as a decoy receptor for the receptor activator of nuclear factor κB ligand (RANKL), the mediator of osteoclastogenesis. This study was designed to explore the possible role of serum OPG and RANKL in detecting bone metastasis in breast cancer and its interaction with clinicopathologic parameters. Serum levels of RANKL and OPG were estimated in 44 metastatic and 36 nonmetastatic breast cancer patients using ELISA kits. Serum OPG levels were significantly reduced in patients with bone metastasis and correlated negatively with the number of bone lesions and CA 15-3 levels. At concentrations ≤82 pg/ml, OPG showed a high specificity in identifying the presence of bone metastasis (92%), albeit with low sensitivity (59%), which improved after the exclusion of diabetics and patients treated with aromatase inhibitors (AI). Serum RANKL levels were significantly higher in the presence of bone metastasis and hypercalcemia. At concentrations >12.5 pg/ml, RANKL had an associated sensitivity of 86%, albeit with low specificity (53%), in detecting bone metastasis. The RANKL/OPG ratio significantly increased in the presence of bone metastasis with appropriate sensitivity and specificity (73% and 72%, respectively) at a cutoff of ≥0.14 for the detection of bone metastasis. Serum OPG and RANKL/OPG ratios are promising biomarkers for detecting bone metastasis in breast cancer patients.

Skeletal Complications and Mortality in Thyroid Cancer: A Population-Based Study

CONTEXT

Although bone is a common site for tumor metastases, the burden of bone events [bone metastases and skeletal-related events (SREs)] in patients with thyroid cancer is not well known.

OBJECTIVE

To measure the prevalence of bone events and their impact on mortality in patients with thyroid cancer.

PATIENTS, DESIGN, AND SETTING

We identified patients diagnosed with thyroid cancer between 1991 and 2011 from the linked Surveillance Epidemiology and End Results-Medicare dataset. Multivariable logistic regression was used to identify the risk factors for bone metastases and SREs. We used Cox proportional hazards regressions to assess the impact of these events on mortality, after adjusting for patient and tumor characteristics.

RESULTS

Of the 30,063 patients with thyroid cancer, 1173 (3.9%) developed bone metastases and 1661 patients (5.5%) developed an SRE. Compared with papillary thyroid cancer, the likelihood of developing bone metastases or an SRE was higher in follicular thyroid cancer [odds ratio (OR), 2.25; 95% confidence interval (CI), 1.85 to 2.74 and OR, 1.40; 95% CI, 1.15 to 1.68, respectively] and medullary thyroid cancer (OR, 2.16; 95% CI, 1.60 to 2.86 and OR, 1.62; 95% CI, 1.23 to 2.11, respectively). The occurrence of a bone event was associated with greater risk of overall and disease-specific mortality [hazard ratio (HR), 2.14; 95% CI, 1.94 to 2.36 and HR, 1.59; 95% CI, 1.48 to 1.71, respectively]. Bone events were a poor prognostic indicator even when compared with patients with other distant metastases (P < 0.001 and P < 0.001 for overall and disease-specific mortality, respectively).

CONCLUSIONS

Bone events in patients with thyroid cancer are a poor prognostic indicator. Patients with follicular and medullary thyroid cancers are at especially high risk for skeletal complications.

A phase 2 trial exploring the clinical and correlative effects of combining doxycycline with bone-targeted therapy in patients with metastatic breast cancer

Background

Bone-targeting agents (BTAs), such as bisphosphonates and denosumab, have demonstrated no discernable effects on tumour response or disease free/overall survival in patients with bone metastases from breast cancer. Doxycycline is both osteotropic and has anti-cancer effects. When combined with zoledronate in animal models, doxycycline showed significantly increased inhibition of tumour burden and increased bone formation. We evaluated the effects of adding doxycycline to ongoing anti-cancer therapy in patients with metastatic breast cancer.

Methods

Breast cancer patients with bone metastases and ≥3 months of BTA use, entered this single-arm study. Patients received doxycycline 100 mg orally, twice a day for 12 weeks. The co-primary endpoints were; effect on validated pain scores (FACT-Bone pain and Brief Pain Inventory) and bone resorption markers (serum C-telopeptide, [sCTx]). All endpoints (pain scores, sCTx, bone-specific alkaline phosphatase, skeletal-related events, toxicity) were evaluated at baseline, 4, 8 and 12 weeks. Bone marrow was sampled at baseline and week 12 for exploratory biomarker analysis.

Results

Out of 37 enroled patients, 27 (73%) completed 12 weeks of therapy. No significant changes were seen in pain scores or bone turnover markers. Failure to complete treatment: drug toxicity (70%) and disease progression (30%). Sixteen (43%) patients had GI adverse events.

Conclusions

Doxycycline 100 mg twice daily for 12 weeks had no significant effects on either bone pain or bone turnover markers. Its toxicity profile in this patient population would make further evaluation challenging.

Future directions for bone metastasis research - highlights from the 2015 bone and the Oncologist new updates conference (BONUS)

In an era of reduced peer-reviewed grant funding, performing academic bone oncology-related research has become increasingly challenging. Over the last 10 years we have held an annual meeting to bring together clinicians, clinician/scientists and basic biomedical researchers interested in the effects of cancer and its treatment on skeletal tissues. In the past these "Bone and the Oncologist New Updates Conference (BONUS)" meetings have served as critical catalyst for initiating productive research collaborations between attendees. The 2015 BONUS meeting format focused on potential key research themes that could form the basis of a coordinated national research strategy to tackle unmet clinical and research needs related to complications associated with cancer metastasis to bone. The three themes planned for discussion were: Is bone metastases-related pain the main issue facing patients? Are there new therapeutic targets for patients with bone metastases? How do we more firmly link basic science with clinical practice? We present a summary of lectures and commentaries from the attendees to serve as an example that other similarly motivated groups can model and share their experiences. It is our hope that these presentations will result in comments, feedback and suggestions from all those researchers interested in this important area.

Bone metastases in patients with small cell lung carcinoma: rate of development, early versus late onset, modality of treatment, and their impact on survival. A single-institution retrospective cohort study

The aim of the present study was to further explore the impact of bone metastases (BMs) and their therapeutic management on the overall prognosis of patients with small cell lung carcinoma (SCLC). We performed a retrospective analysis of medical records of 363 patients with histologically or cytologically confirmed SCLC, diagnosed and treated in the Oncology Unit of Sotiria Athens General Hospital, between January 2003 and December 2012. Demographic and clinicopathological features, including BMs, their time point of development (early onset/at diagnosis versus late onset/at a subsequent time point), treatment modality for BMs (radiotherapy, bisphosphonates or both) and the presence of skeletal-related events (SREs), were correlated with overall survival (OS). Survival analysis was performed using the Kaplan-Meier method, log-rank tests and Cox regression analysis. Overall, 130/363 patients (35.8 %) were diagnosed with either early-onset (97/363 cases, 26.7 %) or late-onset BMs (33/363 cases, 9.1 %). Patients with early-onset BMs had a reduced OS as compared to those with late-onset BMs [Hazard ratio (HR) 0.61; 95 % Confidence interval (CI) 0.41-0.91; p = 0.015) or those without BMs (HR 0.76; 95 % CI 0.6-0.96; p = 0.024). SREs and treatment modality of BMs had no impact on OS. Multiple Cox regression analysis showed that increased age, poor performance status (PS), presence of BMs and early onset BMs were independently associated with reduced OS. The results of our single-institution study suggest that the development of early-onset BMs may represent an independent predictor of a worse prognosis among patients with SCLC, in addition to well-established adverse prognostic factors such as poor PS.