Risk Factors for Developing Skeletal-Related Events in Breast Cancer Patients With Bone Metastases Undergoing Treatment With Bone-Modifying Agents

Novel insights into osteocyte and inter-organ/tissue crosstalk

Osteocyte, a cell type living within the mineralized bone matrix and connected to each other by means of numerous dendrites, appears to play a major role in body homeostasis. Benefiting from the maturation of osteocyte extraction and culture technique, many cross-sectional studies have been conducted as a subject of intense research in recent years, illustrating the osteocyte-organ/tissue communication not only mechanically but also biochemically. The present review comprehensively evaluates the new research work on the possible crosstalk between osteocyte and closely situated or remote vital organs/tissues. We aim to bring together recent key advances and discuss the mutual effect of osteocyte and brain, kidney, vascular calcification, muscle, liver, adipose tissue, and tumor metastasis and elucidate the therapeutic potential of osteocyte.

Do metastatic volumes measured in breast cancer patients with bone metastases correlate with the numbers of skeletal and extraskeletal events?

OBJECTIVES

The study aimed to investigate the relationship between metastatic volume measurement, skeletal-related events, and survival in women diagnosed with breast cancer and bone metastases.

PATIENTS AND METHODS

This retrospective study was conducted with 82 female breast cancer patients (mean age: 53±14.3 years; range, 23 to 87 years) diagnosed, treated, and followed up between January 2005 and December 2019. The collected data included information on metastasis sites and the presence of skeletal-related events. Metastatic volume was measured in two ways: the number of metastases (high to low) and their localization (the first, second, and third groups). The first group consisted of vertebrae, ribs, sternum, and calvarial bones; the second group included scapula, clavicle, proximal humerus, and proximal femur regions; the third group consisted of femur and humerus diaphyseal and distal regions, as well as metastasis regions in other long bones.

RESULTS

Sixty-three (76.8%) patients were diagnosed with ductal carcinoma. Half of the patients had bone metastases at the time of initial diagnosis, while 62 (75.6%) experienced skeletal-related events, with at least three events occurring in 30 (36.6%) patients. Bone pain was the most common skeletal-related event. No correlation was found between metastatic volume measurement based on the localization of bone metastases and the number of bones and the occurrence of skeletal-related events (p>0.05 for each). Patients' survival time spanned from one to 231 months (median: 56.8 months) from their first diagnosis. Patients with high metastatic volume, those in the third group, those whose pelvis and lung were involved, and elderly patients had a shorter survival time (p<0.05 for each).

CONCLUSION

The study indicates that measuring metastatic volume may be a critical factor in evaluating the survival of breast cancer patients with bone metastases. Future prospective and randomized controlled studies can explore the potential of this measurement to create practical clinical tools.

The Importance of Awaiting Biopsy Results in Solitary Pathological Proximal Femoral Fractures : Do We Need to Biopsy Solitary Pathological Fractures?

BACKGROUND

The optimal surgical treatment for patients presenting with (impending and complete) pathological proximal femoral fractures is predicated on prognosis. Guidelines recommend a preoperative biopsy to exclude sarcomas, however no evidence confirms a benefit.

OBJECTIVE

This study aimed to describe the diagnostic accuracy, morbidity and sarcoma incidence of biopsy results in these patients.

MATERIAL AND METHODS

All patients (n = 153) presenting with pathological proximal femoral fractures between 2000 and 2019 were retrospectively evaluated. Patients after inadvertent surgery (n = 25) were excluded. Descriptive statistics were used to evaluate the accuracy and morbidity of diagnostic biopsies.

RESULTS

Of 112/128 patients who underwent biopsy, nine (8%) biopsies were unreliable either due to being inconclusive (n = 5) or because the diagnosis changed after resection (n = 4). Of impending fractures, 32% fractured following needle core biopsy. Median time from diagnosis to surgery was 30 days (interquartile range 21-46). The overall biopsy positive predictive value (PPV) to differentiate between sarcoma and non-sarcoma was 1.00 (95% confidence interval [CI] 0.88-1.00). In patients with a previous malignancy (n = 24), biopsy (n = 23) identified the diagnosis in 83% (PPV 0.91, 95% CI 0.71-0.99), of whom five (24%) patients had a new diagnosis. In patients without a history of cancer (n = 61), final diagnosis included carcinomas (n = 24, 39.3%), sarcomas (n = 24, 39.3%), or hematological malignancies (n = 13, 21.3%). Biopsy (n = 58) correctly identified the diagnosis in 66% of patients (PPV 0.80, 95% CI 0.67-0.90).

CONCLUSION

This study confirms the importance of a preoperative biopsy in solitary pathological proximal femoral fractures due to the risk of sarcoma in patients with and without a history of cancer. However, biopsy delays the time to definite surgery, results can be inconclusive or false, and it risks completion of impending fractures.

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

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

Nomogram Models Based on the Gene Expression in Prediction of Breast Cancer Bone Metastasis

Objective

The aim of this study is to design a weighted co-expression network and build gene expression signature-based nomogram (GESBN) models for predicting the likelihood of bone metastasis in breast cancer (BC) patients.

Methods

Dataset GSE124647 was used as a training set, while GSE16446, GSE45255, and GSE14020 were taken as validation sets. In the training cohort, the limma package in R was adopted to obtain differentially expressed genes (DEGs) between BC nonbone metastasis and bone metastasis patients, which were used for functional enrichment analysis. After weighted co-expression network analysis (WGCNA), univariate Cox regression and Kaplan–Meier plotter analyses were performed to screen potential prognosis-related genes. Then, GESBN models were constructed and evaluated. The prognostic value of the GESBN models was investigated in the GSE124647 dataset, which was validated in GSE16446 and GSE45255 datasets. Further, the expression levels of genes in the models were explored in the training set, which was validated in GSE14020. Finally, the expression and prognostic value of hub genes in BC were explored.

Results

A total of 1858 DEGs were obtained. The WGCNA result showed that the blue module was most significantly related to bone metastasis and prognosis. After survival analyses, GAJ1, SLC24A3, ITGBL1, and SLC44A1 were subjected to construct a GESBN model for overall survival (OS). While GJA1, IGFBP6, MDFI, TGFBI, ANXA2, and SLC24A3 were subjected to build a GESBN model for progression-free survival (PFS). Kaplan–Meier plotter and receiver operating characteristic analyses presented the reliable prediction ability of the models. Cox regression analysis further revealed that GESBN models were independent prognostic predictors for OS and PFS in BC patients. Besides, GJA1, IGFBP6, ITGBL1, SLC44A1, and TGFBI expressions were significantly different between the two groups in GSE124647 and GSE14020. The hub genes had a significant impact on patient prognosis.

Conclusion

Both the four-gene signature and six-gene signature could accurately predict patient prognosis, which may provide novel treatment insights for BC bone metastasis.

Risk factors associated with skeletal-related events following discontinuation of denosumab treatment among patients with bone metastases from solid tumors: A real-world machine learning approach

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This study investigated SRE risk factors after densomuab treatment discontinuation.

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An unbiased machine learning approach was developed to evaluate >60 variables.

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Prior SREs and short denosumab treatment duration were primary risk factors.

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The results can guide denosumab persistence decisions and improve patient outcomes.

Background

Clinical practice guidelines recommend the use of bone-targeting agents for preventing skeletal-related events (SREs) among patients with bone metastases from solid tumors. The anti-RANKL monoclonal antibody denosumab is approved for the prevention of SREs in patients with bone metastases from solid tumors. However, real-world data are lacking on the impact of individual risk factors for SREs, specifically in the context of denosumab discontinuation.

Purpose

We aim to identify risk factors associated with SRE incidence following denosumab discontinuation using a machine learning approach to help profile patients at a higher risk of developing SREs following discontinuation of denosumab treatment.

Methods

Using the Optum PanTher Electronic Health Record repository, patients diagnosed with incident bone metastases from primary solid tumors between January 1, 2007, and September 1, 2019, were evaluated for inclusion in the study. Eligible patients received ≥ 2 consecutive 120 mg denosumab doses on a 4-week (± 14 days) schedule with a minimum follow-up of ≥ 1 year after the last denosumab dose, or an SRE occurring between days 84 and 365 after denosumab discontinuation. Extreme gradient boosting was used to develop an SRE risk prediction model evaluated on a test dataset. Multiple variables associated with patient demographics, comorbidities, laboratory values, treatments, and denosumab exposures were examined as potential factors for SRE risk using Shapley Additive Explanations (SHAP). Univariate analyses on risk factors with the highest importance from pooled and tumor-specific models were also conducted.

Results

A total of 1,414 adult cancer patients (breast: 40%, prostate: 30%, lung: 13%, other: 17%) were eligible, of whom 1,133 (80%) were assigned to model training and 281 (20%) to model evaluation. The median age at inclusion was 67 (range, 19–89) years with a median duration of denosumab treatment of 253 (range, 88–2,726) days; 490 (35%) patients experienced ≥ 1 SRE 83 days after denosumab discontinuation. Meaningful model performance was evaluated by an area under the receiver operating curve score of 77% and an F1 score of 62%; model precision was 60%, with 63% sensitivity and 78% specificity. SHAP identified several significant factors for the tumor-agnostic and tumor-specific models that predicted an increased SRE risk following denosumab discontinuation, including prior SREs, shorter denosumab treatment duration, ≥ 4 clinic visits per month with at least one hospitalization (all-cause) event from the baseline period up to discontinuation of denosumab, younger age at bone metastasis, shorter time to denosumab initiation from bone metastasis, and prostate cancer.

Conclusion

This analysis showed a higher cumulative number of SREs, prior SREs relative to denosumab initiation, a higher number of hospital visits, and a shorter denosumab treatment duration as significant factors that are associated with an increased SRE risk after discontinuation of denosumab, in both the tumor-agnostic and tumor-specific models. Our machine learning approach to SRE risk factor identification reinforces treatment guidance on the persistent use of denosumab and has the potential to help clinicians better assess a patient’s need to continue denosumab treatment and improve patient outcomes.

Regulatory roles of miRNAs 16, 133a, and 223 on osteoclastic bone destruction caused by breast cancer metastasis

Osteolytic bone metastasis leads to skeletal-related events, resulting in a decline in the patient activities and survival; therefore, it is important to understand the mechanism underlying bone metastasis. Recent studies have suggested that microRNAs (miRNAs or miRs) are involved in osteoclast differentiation and/or osteolytic bone metastasis; however, the roles of miRNAs have not been elucidated. In the present study, the roles of miRNAs in bone destruction caused by breast cancer metastasis were investigated in vitro and in vivo. miR-16, miR-133a and miR-223 were transfected into a human breast cancer cell line, MDA-MB-231. The expression of osteolytic factors in conditioned medium (miR-CM) collected from the culture of transfected cells was assessed. To evaluate the effects of miRNAs on osteoclast differentiation and activities, tartrate-resistant acid phosphatase (TRAP) staining and bone resorptive assays were performed in osteoclasts following miR-CM treatment. To create in vivo bone metastasis models for histological and morphometric evaluation, miRNA-transfected MDA-MB-231 cells were transplanted into the proximal tibia of nude mice. Expression of osteolytic factors, including receptor activator for nuclear factor-κB ligand (RANKL), interleukin (IL)-1β, IL-6, parathyroid hormone-related protein (PTHrP), and tumor necrosis factor (TNF), was increased in miR-16-CM, whereas it was decreased in both miR-133a-CM and miR-223-CM. TRAP staining and bone resorptive assays revealed that osteoclast function and activities were promoted by miR-16-CM treatment, whereas they were suppressed by miR-133a-CM and miR-223-CM. Consistent with in vitro findings, in vivo experiments revealed that the overexpression of miR-16 increased osteoclast activities and bone destruction in MDA-MB-231 cells, whereas the opposite results were observed in both miR-133a- and miR-223-transfected MDA-MB-231 cells. Our results indicated that miR-16 promoted osteoclast activities and bone destruction caused by breast cancer metastasis in the bone microenvironment, whereas miR-133a and miR-223 suppressed them. These miRNAs could be potential biomarkers and therapeutic targets for breast cancer bone metastasis.

A predictive biomarker panel for bone metastases: Liquid biopsy approach

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Data mining of published microarray datasets directed us to the identification of a multi gene panel involving of 15 genes that are particular to bone metastases.

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Serum exosomal markers HSP90AA1, SPP1, IL3, and PTK2 found in the present study might be useful in detecting the early spread of bone metastases leading to better clinical outcomes.

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This multi-gene panel and their related pathways may assist as promising conclusion predictors using novel approaches of exosome as liquid biopsy and their application in therapeutic targets in breast and lung cancer patients with bone metastases.

Bone metastases is one of the common metastatic site and leading cause of cancer-related mortality in progressive cancer patients. The purpose of the present study is to establish a liquid biopsy based multi-gene classifier and associated signalling pathways for early diagnosis of bone metastases. We used publically available microarray datasets and analysed them in a platform/chip-specific manner using GeneSpring software. Analyses of gene expression datasets identified 15 consistently over-expressed genes with statistical significance. Further, expression profile of same set of 15 genes were compared in breast and lung cancer exosome derived mRNA with (n = 10) and without (n = 10) bone metastases against healthy controls. ROC curve analysis performed individually for all the 15 genes shortlisted the 5 most relevant genes with significant sensitivity and specificity in both cancers. This liquid biopsy-based bone metastases predictor using multi-gene panel is a unique approach with potential clinical applications for effective management of aggressive cancers.

Can conventional clinical chemistry tests help doctors in the monitoring of oncology patients?

The use of laboratory assays in the diagnostic care of oncology patients can markedly increase the efficacy of cancer treatments. Many cancer-specific biomarker assays have been developed. However, the use of these has some limitations due to their cost. Moreover, not every diagnostic laboratory can perform a complete set of these assays. On the other hand, the smart use of conventional clinical chemistry tests could improve the management of cancer. They could be especially valuable tools in the long-term care of patients with a verified diagnosis. In this review, we discuss the utilization of the conventional clinical chemistry assays for the diagnosis, monitoring and prognosis of various oncological diseases. The use of conventional blood tests to assess the levels of chemical elements, metabolites and proteins (including enzymatic activity measurements) in the care of oncology patients is discussed. We have shown that some clinical chemistry assays could be used in the management of distinct kinds of cancer.

Demethoxycucumin protects MDA-MB-231 cells induced bone destruction through JNK and ERK pathways inhibition

Bone is the most common late metastasis of breast cancer. Bone metastasis causes not only severe bone pain, but also bone-related diseases such as pathological fractures, which are closely related to osteoclasts. The effects of demethoxycurcumin (DMC) on osteoclast biology has not been investigated. In this study, we explored the effects of DMC on MDA-MB-231 cells, MCF-7 cells, and osteoclasts induced by RANKL in vitro, as well as the protective effect on bone destruction of tumor bone metastasis in vivo. DMC showed inhibitory effect on the migration and promotes the apoptosis of MDA-MB-231 and MCF-7 cells. At the same time, DMC inhibited osteoclast maturation and mature osteoclast bone resorption in a dose-dependent manner, and suppressed the expression of osteoclast marker genes TRAP, CTSK, MMP9, V-ATPase-d2 and DC-STAMP significantly. Biochemical data showed that DMC inhibited tumor cells and osteoclasts by inhibiting the early activation of ERK and JNK MAPK pathway. Consistent with the results in vitro, we confirmed that DMC protects bone destruction caused by tumor metastasis in vivo. In short, our study confirmed that DMC could be used as a potential drug for the treatment of tumor bone destruction.

An Italian Retrospective Survey on Bone Metastasis in Melanoma: Impact of Immunotherapy and Radiotherapy on Survival

Background

We performed a multicenter retrospective observational study to investigate the impact of clinical–pathological features and therapeutic strategies on both the complications and survival of patients with bone metastases (BMs) from malignant melanoma.

Patients and Methods

A total of 305 patients with melanoma and radiological evidence of BMs were retrospectively enrolled from 19 Italian centers. All patients received conventional treatments in accordance with each own treating physician’s practice. Both univariate and multivariate models were used to explore the impact of melanoma features, including skeletal-related events (SREs), and different treatments on both overall survival (OS) and time-to-SREs. The chi-squared test evaluated the suitability of several parameters to predict the occurrence of SREs.

Results

Eighty-three percent of patients had metachronous BMs. The prevalent (90%) bone metastatic site was the spine, while 45% had involvement of the appendicular skeleton. Forty-seven percent experienced at least one SRE, including palliative radiotherapy (RT) in 37% of cases. No melanoma-associated factor was predictive of the development of SREs, although patients receiving early treatment with bone-targeted agents showed 62% lower risk and delayed time of SRE occurrence. Median OS from the diagnosis of bone metastasis was 10.7 months. The multivariate analysis revealed as independent prognostic factors the number of BMs, number of metastatic organs, baseline lactate dehydrogenase levels, and treatment with targeted therapy or immunotherapy. Subgroup analyses showed the best OS (median = 16.5 months) in the subset of patients receiving both immunotherapy and palliative RT.

Conclusion

Based on our results, patients undergoing immunotherapy and palliative RT showed an OS benefit suggestive of a possible additive effect. The apparent protective role of bone targeting agent use on SREs observed in our analysis should deserve prospective evaluation.

Impact of Extraskeletal Metastases on Skeletal-Related Events in Metastatic Castration-Resistant Prostate Cancer with Bone Metastases

The therapeutic landscape of metastatic castration-resistant prostate cancer (mCRPC) has substantially evolved over the last decade. Nonetheless, a better understanding of bone-targeted agents (BTAs) action in mCRPC remains an unmet need. Theuse of BTAs aims to reduce the incidence of skeletal-related events (SREs) in patients with mCRPC. Less frequent BTA schedules are currently being studied to minimize adverse events. In this study, the impact of metastatic compartment (bone and extraskeletal metastases (BESM) vs. bone-only metastases (BOM)) on bone biomarker kinetics, time to first on-study SRE, and symptomatic skeletal events (SSEs) is evaluated. This is a retrospective analysis of the prospective, randomized, multicenter clinical trial of denosumab vs. zoledronic acid in patients with mCRPC and bone metastases. A total of 1901 patients were included, 1559 (82.0%) with BOM and 342 with BESM (18.0%). Bone metastases burden was balanced between groups. Baseline levels and normalization rates of corrected urinary N-terminal telopeptide and bone alkaline phosphatase did not differ between groups. However, BESM patients had a higher risk of SREs (adjusted HR 1.21; 95% CI 1.01–1.46; p = 0.043) and SSEs (adjusted HR 1.30; 95% CI 1.06–1.61; p = 0.014). This difference was more pronounced in the first 12 months of BTA treatment.In mCRPC, strategies of BTA schedule de-escalation may take into account presence of extraskeletal metastases.

Role of Bone Targeting Agents in the Prevention of Bone Metastases from Breast Cancer

Breast cancer (BC) is the most common malignancy in women worldwide and leads, in more than 70% of patients with advanced disease, to skeleton colonization and formation of bone metastases (BM). This condition implies a severe disability and deterioration of the quality of life, with consequent additional social costs. In recent decades, several studies explored the role of agents acting within the bone microenvironment to counteract BM development, and several bone-targeting agents (BTAs) have been introduced in the clinical practice to manage bone lesions and reduce the risk of skeletal complications. However, long-term exposure to these agents is not free from potential toxicities and needs careful monitoring. In this context, the potential capability to prevent BM onset in selected BC patients, through the early administration of BTAs, has been explored by several researchers, with the belief that “prevention is better than cure” and that, ultimately, metastatic BC is an incurable condition. Here, we revised the mechanisms of BM development in BC as well as the strategies for selecting high-risk patients suitable for early BTA treatment.

Incidence of patients with bone metastases at diagnosis of solid tumors in adults: a large population-based study

Background

Bones are one of the most common metastatic sites for solid malignancies. Bone metastases can significantly increase mortality and decrease the quality of life of cancer patients. In the United States, around 350,000 people die each year from bone metastases. This study aimed to analyze and update the incidence and prognosis of bone metastases with solid tumors at the time of cancer diagnosis and its incidence rate for each solid cancer.

Methods

We used the Surveillance, Epidemiology, and End Results (SEER) database to find patients diagnosed with solid cancers originating from outside the bones and joints between 2010 and 2016. Data were stratified by age, sex, and race. Patients with a tumor in situ or with an unknown bone metastases stage were excluded. We then selected most of the sites where cancer often occurred, leaving 2,207,796 patients for the final incidence analysis. For the survival analysis, patients were excluded if they were diagnosed at their autopsy or on their death certificate, or had unknown follow-ups. The incidence of bone metastases and overall survival was compared between patients with different primary tumor sites.

Results

We identified 2,470,634 patients, including 426,594 patients with metastatic disease and 113,317 patients with bone metastases, for incidence analysis. The incidence of bone metastases among the metastatic subset was 88.74% in prostate cancer, 53.71% in breast cancer, and 38.65% in renal cancer. In descending order of incidence, there were patients with other cancers in the genitourinary system (except for renal, bladder, prostate, and testicular cancer) (37.91%), adenocarcinoma of the lung (ADC) (36.86%), other gynecologic cancers (36.02%), small-cell lung cancer (SCLC) (34.56%), non-small cell lung cancer not otherwise specified and others [NSCLC (NOS/others)] (33.55%), and bladder (31.08%) cancers. The rate of bone metastases is 23.19% in SCLC, 22.50% in NSCLC (NOS/others), 20.28% in ADC, 8.44% in squamous cell carcinoma of the lung (SCC), and 4.11% in bronchioloalveolar carcinoma [NSCLC (BAC)]. As for the digestive system, the overall bone metastases rate was 7.99% in the esophagus, 4.47% in the gastric cancer, 4.42% in the hepatobiliary cancer, 3.80% in the pancreas, 3.26% in other digestive organs, 1.24% in the colorectum, and 1.00% in the anus. Overall, the incidence rate of bone metastases among the entire cohort in breast and prostate cancer was 3.73% and 5.69%, respectively.

Conclusions

The results of this study provide population-based estimates for the incidence rates of patients with bone metastases at initial diagnosis of their solid tumor. The findings can help clinicians to early detect bone metastases by bone screening to anticipate the occurrence of symptoms and favorably improve the prognosis.

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.

Near-infrared-induced IR780-loaded PLGA nanoparticles for photothermal therapy to treat breast cancer metastasis in bones

Nanodrug-based cancer therapy, especially when treating bone metastases, faces the problem of limited therapeutic efficacy. In this work, we reported a photothermally triggered nanomaterial based on IR780-entrapped poly-lactide-co-glycolide (PLGA) nanoparticles (IR780@PLGA NPs) for the photothermal therapy of bone metastases of breast cancer, in which IR780 converted light into heat to play a role in “burning” the tumors. Anti-tumor therapy studies showed the impressive effectiveness of IR780@PLGA NPs in the photothermal therapy (PTT) of bone metastases. As a result, the IR780@PLGA NPs show a great potential for controlling the bone metastases of breast cancer.

A schematic of PTT using IR780@PLGA NPs with NIR laser-controlled IR780 release.

A gene expression signature-based nomogram model in prediction of breast cancer bone metastases

Breast cancer is prone to form bone metastases and subsequent skeletal‐related events (SREs) dramatically decrease patients’ quality of life and survival. Prediction and early management of bone lesions are valuable; however, proper prognostic models are inadequate. In the current study, we reviewed a total of 572 breast cancer patients in three microarray data sets including 191 bone metastases and 381 metastases‐free. Gene set enrichment analysis (GSEA) indicated less aggressive and low‐grade features of patients with bone metastases compared with metastases‐free ones, while luminal subtypes are more prone to form bone metastases. Five bone metastases‐related genes (KRT23, REEP1, SPIB, ALDH3B2, and GLDC) were identified and subjected to construct a gene expression signature‐based nomogram (GESBN) model. The model performed well in both training and testing sets for evaluation of breast cancer bone metastases (BCBM). Clinically, the model may help in prediction of early bone metastases, prevention and management of SREs, and even help to prolong survivals for patients with BCBM. The five‐gene GESBN model showed some implications as molecular diagnostic markers and therapeutic targets. Furthermore, our study also provided a way for analysis of tumor organ‐specific metastases. To the best of our knowledge, this is the first published model focused on tumor organ‐specific metastases.

Clinical Features and Risk Factors of Skeletal-Related Events in Genitourinary Cancer Patients with Bone Metastasis: A Retrospective Analysis of Prostate Cancer, Renal Cell Carcinoma, and Urothelial Carcinoma

OBJECTIVE

The objective of the present study was to report the incidence of skeletal-related events (SREs) and identify risk factors for SREs in patients with genitourinary cancer with newly diagnosed bone metastasis.

METHODS

This retrospective study included 180 patients with bone metastasis from prostate cancer (PCa; n = 111), renal cell carcinoma (RCC; n = 43), and urothelial carcinoma (UC; n = 26). Clinical factors at the time of diagnosis of bone metastasis were evaluated with Cox proportional hazards regression analysis to identify independent risk factors for SREs.

RESULTS

During follow-up, 29 (26%) patients with PCa, 30 (70%) with RCC, and 15 (58%) with UC developed SREs. Treatment with bone-modifying agents (BMAs) before the development of SREs and within 6 months from the diagnosis of bone metastasis significantly delayed the time to first SRE as compared to nonuse of BMAs. Multivariate analysis identified type of primary cancer (PCa vs. RCC, PCa vs. UC), performance status, and bone pain as significant independent predictive risk factors for SREs.

CONCLUSIONS

Treatment with BMAs significantly delayed the development of first SREs. The identified predictors of SREs might be useful to select patients who would benefit most from early treatment with BMAs.

microRNA-124 inhibits bone metastasis of breast cancer by repressing Interleukin-11

Background

Most patients with breast cancer in advanced stages of the disease suffer from bone metastases which lead to fractures and nerve compression syndromes. microRNA dysregulation is an important event in the metastases of breast cancer to bone. microRNA-124 (miR-124) has been proved to inhibit cancer progression, whereas its effect on bone metastases of breast cancer has not been reported. Therefore, this study aimed to investigate the role and underlying mechanism of miR-124 in bone metastases of breast cancer.

Methods

In situ hybridization (ISH) was used to detect the expression of miR-124 in breast cancer tissues and bone metastatic tissues. Ventricle injection model was constructed to explore the effect of miR-124 on bone metastasis in vivo. The function of cancer cell derived miR-124 in the differentiation of osteoclast progenitor cells was verified in vitro. Dual-luciferase reporter assay was conducted to confirm Interleukin-11 (IL-11) as a miR-124 target. The involvement of miR-124/IL-11 in the prognosis of breast cancer patients with bone metastasis was determined by Kaplan-Meier analysis.

Results

Herein, we found that miR-124 was significantly reduced in metastatic bone tissues from breast cancers. Down-regulation of miR-124 was associated with aggressive clinical characteristics and shorter bone metastasis-free survival and overall survival. Restoration of miR-124 suppressed, while inhibition of miR-124 promoted the bone metastasis of breast cancer cells in vivo. At the cellular level, gain of function and loss-of function assays indicated that cancer cell-derived miR-124 inhibited the survival and differentiation of osteoclast progenitor cells. At the molecular level, we demonstrated that IL-11 partially mediated osteoclastogenesis suppression by miR-124 using in vitro and in vivo assays. Furthermore, IL-11 levels were inversely correlated with miR-124, and up-regulation IL-11 in bone metastases was associated with a poor prognosis.

Conclusions

Thus, the identification of a dysregulated miR-124/IL-11 axis helps elucidate mechanisms of breast cancer metastases to bone, uncovers new prognostic markers, and facilitates the development of novel therapeutic targets to treat and even prevent bone metastases of breast cancer.

Electronic supplementary material

The online version of this article (10.1186/s12943-017-0746-0) contains supplementary material, which is available to authorized users.

Treatment dynamics of bone-targeting agents among men with bone metastases from prostate cancer in the United States

PURPOSE

To examine the dynamics of treatment with 2 bone-targeting agents (BTAs)-denosumab and zoledronic acid-among men with bone metastases from prostate cancer.

METHODS

Using electronic health record data from oncology practices across the US, we identified prostate cancer patients diagnosed with bone metastasis in 2012/2013 without evidence of BTA use within 6 months prior to diagnosis. We examined the risk and predictors of BTA initiation, interruption, and re-initiation.

RESULTS

Among 897 men diagnosed with prostate cancer, the cumulative incidence of BTA initiation after bone metastasis diagnosis was 34% (95% confidence interval [CI], 31-37%) at 30 days, 64% (95% CI, 61-68%) at 180 days, and 88% (95% CI, 85-91%) at 2 years. Denosumab was initiated more frequently than zoledronic acid. Men with diabetes, more bone lesions, history of androgen deprivation therapy, or no hospice enrollment were more likely to initiate treatment. Following initiation, the cumulative incidence of treatment interruption was 17% (95% CI, 14-19%) at 60 days and 70% (95% CI, 66-74%) at 2 years, with interruption more likely among patients receiving emerging therapies for prostate cancer or enrolling in hospice. The cumulative incidence of re-initiation following interruption was 36.3% (95% CI, 32.7-40.2%) at 15 days, 49.8% (95% CI, 45.9-54.1%) at 30 days, and 81.0% (95% CI, 77.5-84.7%) at 1 year.

CONCLUSIONS

Bone-targeting agent therapy is initiated by the majority of men living with bone metastases following a prostate cancer diagnosis; however, the timing of initiation is highly variable. Once on treatment, gaps or interruptions in therapy are common.

Incidence of bone metastases in patients with solid tumors: analysis of oncology electronic medical records in the United States

Background

Bone metastases commonly occur in conjunction with solid tumors, and are associated with serious bone complications. Population-based estimates of bone metastasis incidence are limited, often based on autopsy data, and may not reflect current treatment patterns.

Methods

Electronic medical records (OSCER, Oncology Services Comprehensive Electronic Records, 569,000 patients, 52 US cancer centers) were used to identify patients ≥18 years with a solid tumor diagnosis recorded between 1/1/2004 and 12/31/2013, excluding patients with hematologic tumors or multiple primaries. Each patient’s index date was set to the date of his or her first solid tumor diagnosis in the selection period. Kaplan-Meier analyses were used to quantify the cumulative incidence of bone metastasis with follow-up for each patient from the index date to the earliest of the following events: last clinic visit in the OSCER database, occurrence of a new primary tumor or bone metastasis, end of study (12/31/2014). Incidence estimates and associated 95% confidence intervals (CI) are provided for up to 10 years of follow-up for all tumor types combined and stratified by tumor type and stage at diagnosis.

Results

Among 382,733 study patients (mean age 64 years; mean follow-up 940 days), breast (36%), lung (16), and colorectal (12%) tumors were most common. Mean time to bone metastasis was 400 days (1.1 years). Cumulative incidence of bone metastasis was 2.9% (2.9–3.0) at 30 days, 4.8% (4.7–4.8) at one year, 5.6% (5.5–5.6) at two years, 6.9% (6.8–7.0) at five years, and 8.4% (8.3–8.5) at ten years. Incidence varied substantially by tumor type with prostate cancer patients at highest risk (18% – 29%) followed by lung, renal or breast cancer. Cumulative incidence of bone metastasis increased by stage at diagnosis, with markedly higher incidence among patients diagnosed at Stage IV of whom11% had bone metastases diagnosed within 30 days.

Conclusions

These estimates of bone metastasis incidence represent the experience of a population with longer follow-up than previously published, and represent experience in the recent treatment landscape. Underestimation is possible given reliance on coded diagnoses but the clinical detail available in electronic medical records contributes to the accuracy of these estimates.

Increased risk of SSEs in bone-only metastatic breast cancer patients treated with zoledronic acid

BACKGROUND

Bone represents one of the most common sites to which breast cancer cells metastasize. Patients experience skeletal related adverse events (pathological fractures, spinal cord compressions, and irradiation for deteriorated pain on bone) even during treatment with zoledronic acid (ZA). Therefore, we conducted a retrospective cohort study to investigate the predictive factors for symptomatic skeletal events (SSEs) in bone-metastasized breast cancer (b-MBC) patients.

METHODS

We retrospectively collected data on b-MBC patients treated with ZA. Patient characteristics, including age, subtype, the presence of non-bone lesions, the presence of multiple bone metastases at the commencement of ZA therapy, duration of ZA therapy, the time interval between breast cancer diagnosis and the initiation of ZA therapy, and type of systemic therapy, presence of previous SSE were analyzed using multivariable logistic regression analysis.

RESULTS

The medical records of 183 patients were reviewed and 176 eligible patients were analyzed. The median age was 59 (range, 30-87) years. Eighty-seven patients were aged ≥60 years and 89 patients were aged < 60 years. The proportions of patients with estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2-positive disease were 81.8%, 63.1%, and 17.6%, respectively. Fifty-three patients had bone-only MBC at the commencement of ZA therapy. SSEs were observed in 42 patients. In the multivariable logistic regression analysis, bone-only MBC but not a breast cancer subtype was an independent risk factor for an SSE during ZA therapy (odds ratio: 3.878, 95% confidence interval: 1.647-9.481; p = 0.002).

CONCLUSIONS

Bone-only MBC patients are more likely to experience an SSE even after treatment with ZA.