Management of bone metastases in cancer: a review

The Role of Extracellular Vesicles in Bone Metastasis

Multiple types of cancer have the specific ability to home to the bone microenvironment and cause metastatic lesions. Despite being the focus of intense investigation, the molecular and cellular mechanisms that regulate the metastasis of disseminated tumor cells still remain largely unknown. Bone metastases severely impact quality of life since they are associated with pain, fractures, and bone marrow aplasia. In this review, we will summarize the recent discoveries on the role of extracellular vesicles (EV) in the regulation of bone remodeling activity and bone metastasis occurrence. Indeed, it was shown that extracellular vesicles, including exosomes and microvesicles, released from tumor cells can modify the bone microenvironment, allowing the formation of osteolytic, osteosclerotic, and mixed mestastases. In turn, bone-derived EV can stimulate the proliferation of tumor cells. The inhibition of EV-mediated crosstalk between cancer and bone cells could represent a new therapeutic target for bone metastasis.

Magnetic Resonance-Guided Focused Ultrasound Versus Conventional Radiation Therapy for Painful Bone Metastasis: A Matched-Pair Study

BACKGROUND

Magnetic resonance-guided focused ultrasound (MRgFUS) is an alternative local therapy for patients with painful bone metastasis for whom standard conventional radiation therapy (RT) has failed. However, the therapeutic effects of MRgFUS as a first-line treatment for bone metastasis remain uncertain.

METHODS

A matched-pair study was conducted to compare the therapeutic effects of MRgFUS with those of conventional RT as a first-line treatment for patients with painful bone metastasis. The MRgFUS and RT-treated groups were matched 1:2 by age, sex, primary cancer, pretreatment pain score, and treated site.

RESULTS

According to the criteria for patient eligibility and matching, 21 and 42 patients (total, 63 patients) with bone metastasis treated with MRgFUS and conventional RT, respectively, were enrolled for analyses. The median ages of the MRgFUS and RT-treated patients were 59 and 61 years, respectively. Among the enrolled patients, 52% were male and 48% were female. The results showed that both MRgFUS and RT were effective. However, MRgFUS was more efficient than RT in terms of the time course of pain palliation as it yielded a significantly higher response rate at 1 week after treatment (71% versus 26%, p = 0.0009).

CONCLUSIONS

MRgFUS provides a similar overall treatment response rate but faster pain relief compared with conventional RT and has the potential to serve as the first-line treatment for painful bone metastasis in selected patients.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Serum calcium, alkaline phosphotase and hemoglobin as risk factors for bone metastases in bladder cancer

Early detection of bone metastases is helpful for the treatment of bladder cancer (BC). In this study, we investigated the potential risk factors for bone metastasis in newly diagnosed patients with BC. A total of 902 patients diagnosed with BC between January 2000 and August 2016 were retrospectively reviewed. Of these patient, 50 (5.5%) were identified with bone metastasis. The serum levels of alkaline phosphatase (ALP) and calcium were significantly higher in patients with bone metastases than those without bone metastases (P = 0.015 and P<0.001). And the concentration of hemoglobin (HB) was significant lower in bone metastatic patients compared with non bone metastatic patients (P = 0.009). Multivariate logistic regression analysis indicated that ALP, HB and calcium were independent risk factors for bone metastases in patients with BC. The cut off values of ALP, HB and calcium were 116 U/L, 37.5g/L and 2.54 mmol/L according to the receiver operating characteristic (ROC) curves analysis. And combined ALP, HB with calcium had the highest diagnostic accuracy for predicting bone metastases in BC patients (AUC = 0.760, P<0.001). Therefore, for newly diagnosed patients with BC, the concentrations of ALP >116 U/L, HB <37.5 g/Land calcium >2.54 mmol/L were the risk factors for developing bone metastases. Combined ALP, HB with calcium was more useful to diagnose the bone metastases.

Clinical Characteristics and Prognostic Factors in Bone Metastases from Lung Cancer

Background

This study investigated the prognostic factors of bone metastases from lung cancer.

Material/Methods

From March 2014 to March 2015, 168 patients with bone metastases from lung cancer treated at our hospital were included and the clinical data were reviewed. The Kaplan-Meier survival curves were calculated and analyzed using the log-rank univariate test. Multivariate regression analysis was conducted using Cox’s regression model.

Results

The overall median survival of the 168 patients was 13 months. The 1-year survival was 54.3% and the 2-year survival was 12.9%. Univariate regression analysis indicated that the pathologic types, number of bone metastases, clinical stage, ECOG scores, and serum ALP levels were significantly correlated with survival (P<0.05). Multivariate regression analysis indicated that the number of bone metastases, clinical stage, and serum ALP levels were significantly correlated with prognosis (P<0.05). The risk associated with multiple bone metastases was 1.72 times of that of single bone metastasis (P=0.029); the risk associated with advanced clinical stage was 1.49 times of that of early clinical stage (P=0.001); and the risk associated with a high serum ALP level was 1.75 times of that of the low serum ALP level (P=0.006).

Conclusions

Pathologic types, number of bone metastases, clinical stage, ECOG scores, and serum ALP levels were the prognostic factors for bone metastases from lung cancer.

Bone Metastases: An Overview

Bone is a frequent site of metastases and typically indicates a short-term prognosis in cancer patients. Once cancer has spread to the bones it can rarely be cured, but often it can still be treated to slow its growth. The majority of skeletal metastases are due to breast and prostate cancer. Bone metastasis is actually much more common than primary bone cancers, especially in adults. The diagnosis is based on signs, symptoms and imaging. New classes of drugs and new interventions are given a better quality of life to these patients and improved the expectancy of life. It is necessary a multidisciplinary approach to treat patients with bone metastasis. In this paper we review the types, clinical approach and treatment of bone metastases.

Modern Palliative Treatments for Metastatic Bone Disease: Awareness of Advantages, Disadvantages, and Guidance

BACKGROUND

Metastatic disease is the most common malignancy of the bone. Prostate, breast, lung, kidney, and thyroid cancer account for 80% of skeletal metastases. Bone metastases are associated with significant skeletal morbidity including severe bone pain, pathologic fractures, spinal cord or nerve roots compression, and malignant hypercalcemia. These events compromise greatly the quality of life of the patients. The treatment of cancer patients with bone metastases is mostly aimed at palliation.

OBJECTIVE

This article aims to present these palliative treatments for the patients with bone metastases, summarize the clinical applications, and review the techniques and results.

METHODS

It gives an extensive overview of the possibilities of palliation in patients with metastatic cancer to the bone.

RESULTS AND DISCUSSION

Currently, modern treatments are available for the palliative management of patients with metastatic bone disease. These include modern radiation therapy, chemotherapy, embolization, electrochemotherapy, radiofrequency ablation, and high-intensity focused ultrasound. As such it is of interest for all physicians with no experience with these developments to make palliative procedures safer and more reliable.

Bone Density as a Marker of Response to Radiotherapy in Bone Metastatic Lesions: A Review of the Published Data

Metastases to the bone are presenting in a great percentage of patients with cancer, causing a variety of symptoms, affecting the quality of life and survival of patients. A multidisciplinary approach from different health providers is required for treatment, including radiation oncologists, medical oncologists and surgeons. The role of radiotherapy in the management of bone metastases has long been established through multiple randomized trials. The estimation of response to the therapy is subjective and is based on the palliation of the symptoms that the patients report. However, a quantification of the tumor burden and response to the treatment with the use of an objective method to measure those parameters is a clinical expectation in oncology. The change in bone density in affected areas (mainly lytic) after local radiotherapy, representing the cellular changes that have occurred, is a promising marker of response to treatment.

Magnetic Resonance-Guided High-Intensity-Focused Ultrasound for Palliation of Painful Skeletal Metastases: A Pilot Study

BACKGROUND

Bone is one of the most common sites of metastases, with bone metastases-related pain representing a significant source of morbidity among patients with cancer. Magnetic resonance-guided focused ultrasound is a noninvasive, outpatient modality with the potential for treating painful bone metastases. The aim of this study is to report our initial experience with magnetic resonance-guided focused ultrasound in the treatment of bone metastases and our preliminary analysis of urinary cytokine levels after therapy.

METHODS

This was a single-center pilot study of 10 patients with metastatic cancer to investigate the feasibility of magnetic resonance-guided focused ultrasound for primary pain control in device-accessible skeletal metastases. Treatments were performed on a clinical magnetic resonance-guided focused ultrasound system using a volumetric ablation technique. Primary efficacy was assessed using Brief Pain Inventory scores and morphine equivalent daily dose intake at 3 time points: before, day 14, and day 30 after the magnetic resonance-guided focused ultrasound treatment. Urine cytokines were measured 3 days before treatment and 2 days after the treatment.

RESULTS

Of the 10 patients, 8 were followed up 14 days and 6 were followed up 30 days after the treatment. At day 14, 3 patients (37.5%) exhibited partial pain response and 4 patients (50%) exhibited an indeterminate response, and at day 30 after the treatment, 5 patients (83%) exhibited partial pain response. No treatment-related adverse events were recorded. Of the urine cytokines measured, only Transforming growth factor alpha (TGFα) demonstrated an overall decrease, with a trend toward statistical significance ( P = .078).

CONCLUSION

Our study corroborates magnetic resonance-guided focused ultrasound as a feasible and safe modality as a primary, palliative treatment for painful bone metastases and contributes to the limited body of literature using magnetic resonance-guided focused ultrasound for this clinical indication.

MR thermometry near metallic devices using multispectral imaging

PURPOSE

The lack of a technique for MR thermometry near metal excludes a growing patient population from promising treatments such as MR-guided focused ultrasound therapy. Here we explore the feasibility of multispectral imaging (MSI) for noninvasive temperature measurement in the presence of strong field inhomogeneities by exploiting the temperature dependency of the T₁ relaxation time.

METHODS

A two-dimensional inversion-recovery-prepared MSI pulse sequence (2DMSI) was implemented for artifact-reduced T₁ mapping near metal. A series of T₁ maps was acquired in a metallic implant phantom while increasing the phantom temperature. The measured change in T₁ was analyzed with respect to the phantom temperature. For comparison, proton resonance frequency shift (PRFS) thermometry was performed.

RESULTS

2DMSI achieved artifact-reduced, single-slice T₁ mapping in the presence of strong off-resonance with a spatial resolution of 1.9 mm in-plane and a temporal resolution of 5 min. The maps enabled temperature measurements over a range of 30°C with an uncertainty below 1.4°C. The quality of the resulting temperature maps was independent of the distance from the metal, whereas the PRFS-based temperature measurements were increasingly impaired with increasing off-resonance.

CONCLUSION

We demonstrated the ability to noninvasively measure temperature near metal using MSI and the T₁ temperature sensitivity. Magn Reson Med 77:1162-1169, 2017. © 2016 International Society for Magnetic Resonance in Medicine.

Incidence and outcome of bone metastatic disease at University Malaya Medical Centre

INTRODUCTION

Morbidity and mortality from malignant diseases are usually the result of metastasis. The bone is the third most common site of metastasis.

METHODS

This is a retrospective study of patients with metastatic bone disease who were referred to the Orthopaedic Department of University Malaya Medical Centre, Malaysia, between January 2004 and October 2009.

RESULTS

A total of 151 patients (51.0% men, 49.0% women) had metastatic bone disease, with the highest incidence at the age range of 50-59 years. The commonest primary cancer was breast (23.3%), followed by lung (21.2%), prostate (9.3%), thyroid (7.3%) and renal cell carcinoma (5.3%); unknown primary cancer was 6.6%. There was long bone involvement in 52.7% of cases, axial bone in 44.5%, and both long and axial bones in 2.8%. The majority (90.1%) were symptomatic, with pain as the commonest symptom. 106 (70.2%) patients had pathological fractures. Neurological deficit was reported in 90.7% of patients, with 41.1% having extraskeletal metastases. 67.8% of the lesions were osteolytic, 24.3% were sclerotic, and 7.9%, mixed. Palliative and therapeutic interventions were undertaken for 62.0% of patients. The mean survival times were: breast 21.0; thyroid 20.7; prostate 20.3; lung 16.0; and unknown primary cancer 32.6 months.

CONCLUSION

In our study, breast and lung cancers were the commonest primary cancers in metastatic bone disease. Most patients had more than one site of involvement, pain at presentation and pathological fractures. Surgery is beneficial to relieve pain and improve function and neurology. Duration of survival depends on the type of primary cancer and whether systemic metastasis is present.

Palliative embolization for metastases of the spine

BACKGROUND

To present palliative selective and superselective arterial embolization with N-butyl-cyanoacrylate for cancer patients with spinal metastases.

MATERIALS AND METHODS

We studied the files of 164 cancer patients (94 men and 70 women; mean age 57.6 years; range 35-81 years) treated from March 2003 to March 2013 with 178 selective arterial embolization procedures for metastases of the spine from variable primary cancers. We evaluated the technical success of the embolization procedure with post-procedural angiography, the clinical effect in pain relief, need for analgesics and tumor size reduction, and the embolization-related complications.

RESULTS

Post-embolization angiography showed complete occlusion of the pathological feeding vessels in all procedures. Pain score and need for analgesics reduced by 50 % in 159 patients (97 %); no response was achieved in five patients with metastases of the sacrum. The mean duration of pain relief was 9.2 months (range 1-12 months). Metastatic tumor size reduced from a mean of 5.5 cm (range 3.5-7.5 cm) pre-embolization to a mean of 4.5 cm (range 3-5 cm) at the 6-month follow-up; the difference was not statistically significant. Ninety-three patients (56.7 %) experienced embolization-related complications the most common being post-embolization syndrome (80 patients, 48.8 %) followed by leg paresthesias (ten patients, 6 %), and rupture of a lumbar artery (one patient, 0.6 %).

CONCLUSION

Selective arterial embolization with N-butyl-cyanoacrylate should be considered for pain palliation of patients with metastases of the spine. However, pain relief is temporary, and complications, although minor may occur.

Helical coil electrode radiofrequency ablation designed for application in osteolytic vertebral tumors--initial evaluation in a porcine model

BACKGROUND CONTEXT

Radiofrequency ablation (RFA) is emerging as a complementary treatment for vertebral metastases. Traditional RFA induces frictional heating leading to local tissue necrosis but often yields small, incomplete, and inhomogeneous zones of ablation in bone. We have developed a new bone-specific RFA electrode that uses a nontraditional frequency (27.12 MHz) and geometry (helical), exploiting a magnetic field and an electric field to generate larger and more comprehensive treatment zones.

PURPOSE

The purpose of the study was to evaluate the feasibility and safety of the Bone Coil RFA electrode in the spine.

STUDY DESIGN

This is a preclinical in vivo study based on basic science.

METHODS

Under institutional approval, six healthy Yorkshire pigs received a sham and an RF treatment in two adjacent cervical vertebrae. To deploy the Bone Coil RFA device in dense porcine vertebrae, a surgical approach was required; an irrigated coring drill bit created a cylindrical path in the vertebral bodies through which the RFA electrodes were placed. The electronic circuit was completed by four grounding pads. Treatment was delivered for 10 minutes at 20 W (n=1), 25 W (n=1), and 30 W (n=4). To monitor the thermal rise and for safety, fiber-optic probes recorded temperatures in the center of each coil and near the spinal foramen. After the procedure, animals were monitored for 2 weeks. Magnetic resonance imaging (MRI) was completed immediately after treatment and at 14 days. Magnetic resonance image segmentation and histology were used to evaluate the ablation volume.

RESULTS

Comprehensive treatment of the porcine vertebrae was demonstrated by temperature monitoring, MRI, and histology. Large zones of RF ablation were obtained (RF: 3.72±0.73 cm3 vs. sham: 1.98±0.16 cm3, p<.05), confined within the vertebral body. Internal temperatures were elevated with RF (66.1 °C-102.9 °C), without temperature rise outside of the vertebrae (38.2 °C ± 1.5 °C). Mobility, neurological responses, and behavior were normal, consistent with preprocedural examination. Magnetic resonance imaging best visualized ablation at Day 14. Histology revealed comprehensive homogeneous coagulative necrosis with little peripheral sign of repair.

CONCLUSIONS

The Bone Coil RFA device created large intravertebral ablation volumes with no neurologic sequelae. Radiofrequency thermal ablation (clearly distinguished from the much smaller effects arising from core drilling) corresponded to the homogeneous necrosis visible on histology.

Methotrexate-loaded glass ionomer cements for drug release in the skeleton: An examination of composition-property relationships

Chemotherapeutic-loaded bone cement may be an effective method of drug delivery for the management of cancer-related vertebral fractures that require cement injection for pain relief. Recent advancements in the development of aluminum-free glass ionomer cements (GICs) have rendered this class of biomaterials clinically viable for such applications. To expand the therapeutic benefits of these materials, this study examined, for the first time, their drug delivery potential. Through incrementally loading the GIC with methotrexate (MTX) by up to 10-wt%, composition-property relationships were established, correlating MTX loading with working time and setting time, as well as compressive strength, drug release, and cytotoxic effect over 31 days. The most significant finding of this study was that MTX was readily released from the GIC, while maintaining cytotoxic activity. Release correlated linearly with initial loading and appeared to be diffusion mediated, delivering a total of 1-2% of the incorporated drug. MTX loading in this range exerted minimal effects to handling and strength, indicating the clinical utility of the material was not compromised by MTX loading. The MTX-GIC systems examined herein are promising materials for combined structural delivery applications.

Disruption of crosstalk between mesenchymal stromal and tumor cells in bone marrow as a therapeutic target to prevent metastatic bone disease

Skeletal metastasis is a serious complication of many primary cancers. A common feature of tumor cells that metastasize to the bone marrow microenvironment is that they initiate a cascade of events, recruiting and presumably/potentially altering the phenotype of bone marrow mesenchymal stromal cells (MSC) to produce an environment that allows for tumor growth and in some cases, drug-resistant dormancy of latent cancer cells. Consequently the MSC population can contribute to metastatic disease through several distinct mechanisms by differentiating into cancer-associated fibroblasts (CAFs). Understanding the expression and epigenetic changes that occur as normal MSCs become associated with metastatic tumors would reveal possible therapeutic targets for treating skeletal metastasis.

Targeted treatments of bone metastases in patients with lung cancer

Until now ~30–40% of patients with advanced lung cancer develop bone metastases, but as the newer therapies are extending survival, the chance of developing bone metastases increases. Bone metastases cause skeletal-related events (SREs) such as pathologic fractures, spinal cord compression, radiation therapy or surgery to bone, or hypercalcemia, which can have debilitating consequences affecting patients’ health-related quality of life (HR-QOL) and performance status (PS). Poor PS then prevents the patients to receive further lines of treatments, which are available today. SREs are associated with increased economic costs. In one clinical trial, the median time to first SRE was only 5 months. Early detection of bone metastases can prevent SREs and avoid inappropriate implementation of major surgery or chemoradiation therapy. With the new generation bisphosphonate zoledronic acid (ZA) or denosumab (anti-RANKL activity), one can reduce the number of patients who experience SREs, decrease the annual incidence of SREs and delay the median time to first SRE. These agents are effective even after the onset of SREs. They are well tolerated, with manageable side effects. The biochemical markers of bone metabolism especially N-telopeptide of type I collagen and bone specific alkaline phosphatase (BALP) can be both prognostic and predictive markers for the patients with bone metastases from non-small cell lung cancer (NSCLC). Anticancer activity of ZA and denosumab further supports their use as soon as bone metastases are diagnosed in patients with NSCLC. Further trials will inform us about the efficacy of these agents for prevention of bone metastases and even about possible effects on visceral metastases.

Denosumab: A comprehensive review

The clinical sequelae from bone metastases, termed skeletal-related events (SREs), are among the most frequent and debilitating complications in patients with advanced cancer. Bone metastases are characterized by pathologically increased osteoclast activity, and accumulating evidence indicates that tumor cells interact within the bone to stimulate the receptor activator of nuclear factor kB (RANK)-RANK ligand (RANKL) pathway. RANKL is an essential mediator of osteoclast formation, function, and survival. Because of the central role of RANKL in cancer-induced bone destruction, the inhibition of RANKL has the potential to result in the reduction of pathologic bone resorption. Denosumab is a fully human monoclonal antibody specific for RANKL that inhibits the formation, activation, and survival of osteoclasts. This in turn decreases bone resorption and reduces cancer-induced bone destruction. In this review, we give an overview of the drug Denosumab with its history, mechanism of action, clinical trial data, adverse effects, and future challenges.

Biomechanical properties of bone treated by magnetic resonance-guided focused ultrasound - an in vivo porcine model study

The magnetic resonance-guided focused ultrasound (MRgFUS) system uses MR imaging for real-time aiming of thermal ablation of bone and soft tissue tumors. Past clinical studies showed no increase in fracture rate after MRgFUS treatment. The purpose of this study was to determine the effect of MRgFUS treatment on mechanical properties of bone and correlate the effect to histological findings of treated bone. Four fully grown mini-pigs were treated by MRgFUS. Six consecutive right normal ribs were treated in each animal, and the left corresponding ribs served as controls. The animals were sacrificed at pre-set intervals (0, 2, 6 and 12weeks after treatment), and the treated and control bones were extracted. Mechanical properties of each bone were examined using three points bending studies for comparing treated bones to the corresponding controls. Histologic properties using Masson and hematoxylin-eosin stains were also compared. The ratio between treated and control biomechanical properties showed reduction in bone biomechanical properties at 6weeks post-MRgFUS treatment. The mean±SD yield load ratio and maximum ratios were 0.69±0.11 and 0.71±0.13, respectively (both p=0.031). These findings showed some recovery trend at 12weeks after treatment. Histological analysis showed a reduction in mean osteon size at 2weeks after treatment (0.58×10(-3)±0.1×10(-3)mm and 0.16×10(-3)±0.017×10(-3)mm) in control vs. treated bones, respectively (p=0.005). Treatment with the MRgFUS system resulted in a ~30% reduction in mechanical strength at 6weeks post-treatment. The reduction showed a reversible trend, with a 25%-20% decrease in strength at 12weeks post-treatment.

Biochemical markers of bone turnover and clinical outcome in patients with renal cell and bladder carcinoma with bone metastases following treatment with zoledronic acid: The TUGAMO study

Background:

Levels of bone turnover markers (BTM) might be correlated with outcome in terms of skeletal-related events (SRE), disease progression, and death in patients with bladder cancer (BC) and renal cell carcinoma (RCC) with bone metastases (BM). We try to evaluate this possible correlation in patients who receive treatment with zoledronic acid (ZOL).

Methods:

This observational, prospective, and multicenter study analysed BTM and clinical outcome in these patients. Serum levels of bone alkaline phosphatase (BALP), procollagen type I amino-terminal propeptide (PINP), and beta-isomer of carboxy-terminal telopeptide of type I collagen (β-CTX) were analysed.

Results:

Patients with RCC who died or progressed had higher baseline β-CTX levels and those who experienced SRE during follow-up showed high baseline BALP levels. In BC, a poor rate of survival was related with high baseline β-CTX and BALP levels, and new SRE with increased PINP levels. Cox univariate analysis showed that β-CTX levels were associated with higher mortality and disease progression in RCC and higher mortality in BC. Bone alkaline phosphatase was associated with increased risk of premature SRE appearance in RCC and death in BC.

Conclusion:

Beta-isomer of carboxy-terminal telopeptide of type I collagen and BALP can be considered a complementary tool for prediction of clinical outcomes in patients with BC and RCC with BM treated with ZOL.

Overall survival improvement in patients with lung cancer and bone metastases treated with denosumab versus zoledronic acid: subgroup analysis from a randomized phase 3 study

INTRODUCTION

Denosumab, a fully human anti-RANKL monoclonal antibody, reduces the incidence of skeletal-related events in patients with bone metastases from solid tumors. We present survival data for the subset of patients with lung cancer, participating in the phase 3 trial of denosumab versus zoledronic acid (ZA) in the treatment of bone metastases from solid tumors (except breast or prostate) or multiple myeloma.

METHODS

Patients were randomized 1:1 to receive monthly subcutaneous denosumab 120 mg or intravenous ZA 4 mg. An exploratory analysis, using Kaplan-Meier estimates and proportional hazards models, was performed for overall survival among patients with non-small-cell lung cancer (NSCLC) and SCLC.

RESULTS

Denosumab was associated with improved median overall survival versus ZA in 811 patients with any lung cancer (8.9 versus 7.7 months; hazard ratio [HR] 0.80) and in 702 patients with NSCLC (9.5 versus 8.0 months; HR 0.78) (p = 0.01, each comparison). Further analysis of NSCLC by histological type showed a median survival of 8.6 months for denosumab versus 6.4 months for ZA in patients with squamous cell carcinoma (HR 0.68; p = 0.035). Incidence of overall adverse events was balanced between treatment groups; serious adverse events occurred in 66.0% of denosumab-treated patients and 72.9% of ZA-treated patients. Cumulative incidence of osteonecrosis of the jaw was similar between groups (0.7% denosumab versus 0.8% ZA). Hypocalcemia rates were 8.6% with denosumab and 3.8% with ZA.

CONCLUSION

In this exploratory analysis, denosumab was associated with improved overall survival compared with ZA, in patients with metastatic lung cancer.

Monoclonal antibody-based immunotherapy for multiple myeloma

Multiple myeloma (MM) is a life-threatening hematological malignancy. High-dose chemotherapy followed by autologous stem cell transplantation is a relatively effective treatment, but disease recurrence remains a major obstacle. Allogeneic transplantation may result in durable responses and cure due to antitumor immunity mediated by donor lymphocytes. However, morbidity and mortality related to graft-versus-host disease remain a challenge. Recent advances in understanding the interaction between the immune system of the patient and the malignant cells are influencing the design of clinically more efficient study protocols for MM. This review will focus on MM antigens and their specific antibodies. These monoclonal antibodies are an attractive therapeutic tool for MM humoral immunotherapy, with most promising preclinical results.

Hyperthermia in bone generated with MR imaging-controlled focused ultrasound: control strategies and drug delivery

PURPOSE

To evaluate the feasibility of achieving image-guided drug delivery in bone by using magnetic resonance (MR) imaging-controlled focused ultrasound hyperthermia and temperature-sensitive liposomes.

MATERIALS AND METHODS

Experiments were approved by the institutional animal care committee. Hyperthermia (43°C, 20 minutes) was generated in 10-mm-diameter regions at a muscle-bone interface in nine rabbit thighs by using focused ultrasound under closed-loop temperature control with MR thermometry. Thermosensitive liposomal doxorubicin was administered systemically during heating. Heating uniformity and drug delivery were evaluated for control strategies with the temperature control image centered 10 mm (four rabbits) or 0 mm (five rabbits) from the bone. Simulations estimated temperature elevations in bone. Drug delivery was quantified by using the fluorescence of doxorubicin extracted from bone marrow and muscle and was compared between treated and untreated thighs by using the one-sided Wilcoxon signed rank test.

RESULTS

With ultrasound focus and MR temperature control plane 0 mm and 10 mm from the bone interface, average target region temperatures were 43.1°C and 43.3°C, respectively; numerically estimated bone temperatures were 46.8°C and 78.1°C. The 10-mm offset resulted in thermal ablation; numerically estimated muscle temperature was 66.1°C at the bone interface. Significant increases in doxorubicin concentration occurred in heated versus unheated marrow (8.2-fold, P = .002) and muscle (16.8-fold, P = .002). Enhancement occurred for 0- and 10-mm offsets, which suggests localized drug delivery in bone is possible with both hyperthermia and thermal ablation.

CONCLUSION

MR imaging-controlled focused ultrasound can achieve localized hyperthermia in bone for image-guided drug delivery in bone with temperature-sensitive drug carriers.

Estimated number of prevalent cases of metastatic bone disease in the US adult population

BACKGROUND

The prevalence of metastatic bone disease in the US population is not well understood. We sought to estimate the current number of US adults with metastatic bone disease using two large administrative data sets.

METHODS

Prevalence was estimated from a commercially insured cohort (ages 18-64 years, MarketScan database) and from a fee-for-service Medicare cohort (ages ≥65 years, Medicare 5% database) with coverage on December 31, 2008, representing approximately two-thirds of the US population in each age group. We searched for claims-based evidence of metastatic bone disease from January 1, 2004, using a combination of relevant diagnosis and treatment codes. The number of cases in the US adult population was extrapolated from age- and sex-specific prevalence estimated in these cohorts. Results are presented for all cancers combined and separately for primary breast, prostate, and lung cancer.

RESULTS

In the commercially insured cohort (mean age = 42.3 years [SD = 13.1]), we identified 9505 patients (0.052%) with metastatic bone disease. Breast cancer was the most common primary tumor type (n = 4041). In the Medicare cohort (mean age = 75.6 years [SD = 7.8]), we identified 6427 (0.495%) patients with metastatic bone disease. Breast (n = 1798) and prostate (n = 1862) cancers were the most common primary tumor types. We estimate that 279,679 (95% confidence interval: 274,579-284,780) US adults alive on December 31, 2008, had evidence of metastatic bone disease in the previous 5 years. Breast, prostate, and lung cancers accounted for 68% of these cases.

CONCLUSION

Our findings suggest that approximately 280,000 US adults were living with metastatic bone disease on December 31, 2008. This likely underestimates the true frequency; not all cases of metastatic bone disease are diagnosed, and some diagnosed cases might lack documentation in claims data.

Bisphosphonates as radionuclide carriers for imaging or systemic therapy

Bisphosphonates (BP's), biologically stable analogs of naturally occurring pyrophosphates, became the treatment of choice for pathologic conditions characterized by increased osteoclast-mediated bone resorption, namely Paget's disease, osteoporosis and tumor bone disease. Moreover, the clinical success of BP's is also associated with their use in (99m)Tc-based radiopharmaceuticals for bone imaging. In addition to the successful delivery of (99m)Tc (γ-emitter) to bone, BP's have also been used to deliver β(-)-particle emitting radiometals (e.g.(153)Sm, (186/188)Re) for bone-pain palliation. The main goal of this Review is to update the most recent research efforts toward the synthesis, characterization and biological evaluation of novel BP-containing radiometal complexes and radiohalogenated compounds for diagnostic or therapeutic purposes. The structure and in vivo properties of those compounds will be discussed and compared to the clinically available ones, namely in terms of image quality and therapeutic effect. We will also mention briefly the use of BP's as carriers of multimodal nuclear and optical imaging probes.

Metastases of the pelvis: does resection improve survival?

Limited data are available to compare the outcome of wide en bloc resection and curettage for pelvic metastases. Previous studies have reported that curettage is associated with high mortality and decreased survival compared to wide resection and have justified consideration of a radical surgical approach to achieve pain palliation and tumor control. In this study, we aimed to evaluate the role of curettage/marginal resection compared to wide en bloc resection for patients with pelvic metastases. The hypothesis was that wide resection does not improve survival even in patients with solitary pelvic metastases.Between 1985 and 2009, twenty-one patients with pelvic metastases were treated with wide resection (12 patients) and curettage/marginal resection (9 patients) and adjuvants. Sixteen patients had solitary pelvic metastases. At a mean of 28 months (range, 2-152 months), we found no difference in survival to death or local recurrence with wide en bloc resection compared to curettage or marginal resection, even in patients with solitary pelvic metastases. The overall survival to death and local recurrence was 30% and 47% at 60 months, respectively. Survival to death of patients treated with wide resection was 18% at 60 months compared to 62% at 60 months of patients treated with curettage/marginal resection; no difference in survival to death between wide resection and curettage/marginal resection was observed even in patients with solitary pelvic metastases. Survival to local recurrence of patients treated with wide en bloc resection was 67% at 36 months compared to 26% at 36 months of patients treated with curettage/marginal resection; this was also not statistically significant. One patient treated with wide resection for a solitary pelvic metastasis had a postoperative complication.

Selective arterial embolisation for bone tumours: experience of 454 cases

PURPOSE

The authors present the experience of a single institution with selective arterial embolisation for primary and metastatic bone tumours.

MATERIALS AND METHODS

A total of 365 patients were treated with 454 embolisation procedures from December 2002 to April 2010. Embolisation was the primary treatment for benign bone tumours, adjuvant treatment to surgery for benign and malignant bone tumours and palliative treatment for bone sarcomas and metastases. Indications for repeat embolisation included pain or imaging evidence of progressive disease: 105 patients had repeat embolisation at the same location at an interval of 1-3 months; 260 patients had one embolisation, 78 had two and 29 had three or more. In all patients, N-2-butyl cyanoacrylate (NBCA) in 33% lipiodol was the embolic agent used.

RESULTS

A total of 419 of the 454 embolisations (93%) were technically successful. In 35 cases, embolisation was not feasible because of poor lesion vascularisation (21 patients with bone metastases and two with aneurysmal bone cysts), origin of the Adamkiewicz artery in the embolisation field (four patients with bone metastases and one with aneurysmal bone cyst), atheromatosis and arteriosclerosis (five patients with bone metastases) and anatomical and technical problems such as small-calibre vessels, many branches and acute vessel angles (two patients with bone metastases). A clinical response was achieved in 406 of the 419 procedures (97%), and no response in 13 procedures in patients with pelvis and sacrum tumours. Complications included postembolisation syndrome in 81 patients (22%), transient paraesthesias in 41 (11%), skin breakdown and subcutaneous necrosis at the shoulder and pelvis in five (1.4%) and paresis of the sciatic nerve in one (0.3%).

CONCLUSIONS

We recommend embolisation as primary or palliative treatment or an adjunct to surgery for tumours of variable histology. Strict adherence to the principles of transcatheter embolisation is important. Arteries feeding the tumour and collaterals must be evaluated carefully and catheterised superselectively to protect the normal tissues. NBCA is considered the most appropriate embolic agent for small-vessel occlusion without major complications.

Selective embolization with N-butyl cyanoacrylate for metastatic bone disease

PURPOSE

To evaluate the clinical and imaging effect of selective embolization using N-butyl cyanoacrylate (NBCA) as palliation for bone metastases.

MATERIALS AND METHODS

The procedures and effect of 309 embolizations performed in 243 patients were retrospectively analyzed; 56 patients had repeat embolization at the same location at 1-3 months; 197 patients had embolization for progressive bone metastases after radiation therapy. The mean tumor diameter before embolization was 7.8 cm (range 5-30 cm). In all patients, embolizations were performed under local anesthesia through transfemoral catheterization using NBCA in 33% ethiodized oil. The technical success of embolization was evaluated by angiography after completion of the procedure. The clinical and imaging effect was evaluated at follow-up examinations with a pain score scale and use of analgesics, hypoattenuating areas, tumor size, and ossification.

RESULTS

In all 309 embolizations, postprocedural angiography showed complete occlusion of metastatic blood supply and greater than 80% devascularization of the lesions. Greater than 50% reduction of pain score and analgesic doses was achieved in 97% of procedures. The mean duration of pain relief was 8.1 months (range 1-12 months). The mean maximal tumor diameter after embolization was 5.5 cm (range 2-20 cm). Variable ossification appeared in 65 patients. Postembolization syndrome, ischemic pain at the site of embolization, paresthesias, skin breakdown, and subcutaneous necrosis were observed in 87 patients.

CONCLUSIONS

Selective embolization with NBCA is a safe and effective palliative treatment for metastatic bone lesions of various primary cancers; pain relief is temporary.

Randomized, double-blind study of denosumab versus zoledronic acid in the treatment of bone metastases in patients with advanced cancer (excluding breast and prostate cancer) or multiple myeloma

PURPOSE

This study compared denosumab, a fully human monoclonal anti-receptor activator of nuclear factor kappa-B ligand antibody, with zoledronic acid (ZA) for delaying or preventing skeletal-related events (SRE) in patients with advanced cancer and bone metastases (excluding breast and prostate) or myeloma.

PATIENTS AND METHODS

Eligible patients were randomly assigned in a double-blind, double-dummy design to receive monthly subcutaneous denosumab 120 mg (n = 886) or intravenous ZA 4 mg (dose adjusted for renal impairment; n = 890). Daily supplemental calcium and vitamin D were strongly recommended. The primary end point was time to first on-study SRE (pathologic fracture, radiation or surgery to bone, or spinal cord compression).

RESULTS

Denosumab was noninferior to ZA in delaying time to first on-study SRE (hazard ratio, 0.84; 95% CI, 0.71 to 0.98; P = .0007). Although directionally favorable, denosumab was not statistically superior to ZA in delaying time to first on-study SRE (P = .03 unadjusted; P = .06 adjusted for multiplicity) or time to first-and-subsequent (multiple) SRE (rate ratio, 0.90; 95% CI, 0.77 to 1.04; P = .14). Overall survival and disease progression were similar between groups. Hypocalcemia occurred more frequently with denosumab. Osteonecrosis of the jaw occurred at similarly low rates in both groups. Acute-phase reactions after the first dose occurred more frequently with ZA, as did renal adverse events and elevations in serum creatinine based on National Cancer Institute Common Toxicity Criteria for Adverse Events grading.

CONCLUSION

Denosumab was noninferior (trending to superiority) to ZA in preventing or delaying first on-study SRE in patients with advanced cancer metastatic to bone or myeloma. Denosumab represents a potential novel treatment option with the convenience of subcutaneous administration and no requirement for renal monitoring or dose adjustment.

Clinical development of anti-RANKL therapies for treatment and prevention of bone metastasis

The clinical sequelae from bone metastases, termed skeletal-related events, are among the most frequent and debilitating complications in patients with advanced cancer. Bone metastases are characterized by pathologically increased osteoclast activity, and accumulating evidence indicates that tumor cells interact within the bone to stimulate the RANK-RANK ligand (RANKL) pathway. RANKL is an essential mediator of osteoclast formation, function, and survival. Because of the central role of RANKL in cancer-induced bone destruction, the inhibition of RANKL has the potential to result in the reduction of pathologic bone resorption. Denosumab is a fully human monoclonal antibody specific for RANKL that inhibits the formation, activation, and survival of osteoclasts. This in turn decreases bone resorption and reduces cancer-induced bone destruction. As a result of its unique and specific mechanism of action, denosumab is being investigated for use in patients with advanced malignancies involving bone to prevent the occurrence of skeletal-related events.

Validity of the recorded International Classification of Diseases, 10th edition diagnoses codes of bone metastases and skeletal-related events in breast and prostate cancer patients in the Danish National Registry of Patients

Objective:

The clinical history of bone metastases and skeletal-related events (SREs) secondary to cancers is not well understood. In support of studies of the natural history of bone metastases and SREs in Danish prostate and breast cancer patients, we estimated the sensitivity and specificity of hospital diagnoses for bone metastases and SREs (ie, radiation therapy to the bone, pathological or osteoporotic fractures, spinal cord compression and surgery to the bone) in a nationwide medical registry in Denmark.

Study design and setting:

In North Jutland County, Denmark, we randomly sampled 100 patients with primary prostate cancer and 100 patients with primary breast cancer diagnoses from the National Registry of Patients (NRP), during the period January 1st, 2000 to December 31st, 2000 and followed them for up to five years after their cancer diagnosis. We used information from medical chart reviews as the reference for estimating sensitivity, and specificity of the NRP International Classification of Diseases, 10th edition (ICD-10) coding for bone metastases and SRE diagnoses.

Results:

For prostate cancer, the overall sensitivity of bone metastases or SRE coding in the NRP was 0.54 (95% confidence interval [CI]: 0.39–0.69), and the specificity was 0.96 (95% CI: 0.87–1.00). For breast cancer, the overall sensitivity of bone metastases or SRE coding in the NRP was 0.58 (95% CI: 0.34–0.80), and the specificity was 0.95 (95% CI: 0.88–0.99).

Conclusion:

We measured the validity of ICD-10 coding in the Danish NRP for bone metastases and SREs in prostate and breast cancer patients and found it has adequate sensitivity and high specificity. The NRP remains a valuable tool for clinical epidemiological studies of bone metastases and SREs.

Bone imaging in prostate cancer

Bone metastases of solid tumors are common, and about 80% of them occur in patients with breast, lung or prostate cancer. Bone metastases can be suspected clinically and by laboratory tests; however, a final diagnosis relies on radiographic evidence. Bone metastases of prostate cancer usually have osteoblastic characteristics, manifested by pathological bone resorption and formation. Conventional bone scans (e.g. with (99m)Tc-labeled methylene diphosphonate) are preferred to plain-film radiography for surveillance of the entire skeleton. Radiologic diagnosis of bone metastases, particularly in patients with low burden of disease, is difficult because noncancerous bone lesions that mimic cancer are common. Conventional bone scans are limited by their low sensitivity and high false-negative rate (up to 40%) compared with advanced bone-imaging modalities such as PET, PET-CT and MRI, which might assist or replace conventional scanning methods. The correct diagnosis of bone involvement in prostate cancer is crucial to assess the effects of therapy on the primary tumor, the patient's prognosis, and the efficacy of bone-specific treatments that can reduce future bone-associated morbidity. In addition, predictive tools such as nomograms enable the identification of patients at risk of bone involvement during the course of their disease. Such tools may limit treatment costs by avoidance of unnecessary tests and might reduce both short-term and long-term complication rates.

Local control of regional and metastatic lesions and indication for systemic chemotherapy in patients with non-small cell lung cancer

Systemic chemotherapy is the mainstay of treatment in patients with advanced non-small cell lung cancer. Local control of regional and metastatic lesions may be needed before systemic therapy can be started in patients with pleural effusions or bone or brain metastases. The indication for systemic chemotherapy depends on the symptoms and performance status of the patient. In addition, a risk assessment considering complications such as hemodynamic and respiratory compromise by effusions, pathological bone fractures, and neurologic deterioration caused by brain metastases is critical in selecting which patients should receive first-line systemic chemotherapy before local therapy, although predictive factors for these complications have not yet been established. Chemotherapy has been considered to have only a limited role in the treatment of patients with pleural effusions and brain and bone metastases, but recently developed anticancer agents have shown substantial antitumor effects in these types of patients with a good general condition.