Zoledronic acid is superior to pamidronate for the treatment of bone metastases in breast carcinoma patients with at least one osteolytic lesion

A Comparison of the Efficacy and Safety of Denosumab and Zoledronic Acid in Patients with Bone Metastatic Breast Cancer Receiving CDK4/6 Inhibitor Therapy

Background and Objectives: Bone metastases in patients can cause significant quality-of-life declines due to skeletal-related events (SREs). SRE is defined as the occurrence of radiotherapy for bone pain, pathologic fracture, bone surgery, spinal cord compression, or hypercalcemia. Bone-modifying agents (BMAs), such as denosumab and zoledronic acid, are crucial in reducing the frequency and severity of SREs. The inhibition of cyclin-dependent kinase 4/6 (CDK4/6) inhibitors has emerged as the standard treatment for hormone receptor-positive metastatic breast cancer, demonstrating significant improvements in survival outcomes. This study aims to compare the effectiveness of denosumab and zoledronic acid in preventing SRE in patients receiving CDK4/6 inhibitors with endocrine therapy. Materials and Methods: This retrospective study included 328 patients diagnosed with bone metastatic breast cancer receiving first-line CDK4/6 inhibitor therapy (palbociclib or ribociclib). Patients were assigned to receive either subcutaneous denosumab or intravenous zoledronic acid every 4 weeks. Time to the first skeletal-related event post bone-modifying agent initiation, SRE incidence, and the safety data were evaluated. The data were analyzed using independent samples t-tests, chi-square tests, and Kaplan-Meier methods for time-to-event data. Results: In the denosumab group, the median time to the first skeletal-related event was significantly longer than in the zoledronic acid group (44.55 months and 29.16 months, respectively). Denosumab treatment was associated with a statistically significant reduction in the risk of developing the first SRE after bone-modifying agent initiation compared to zoledronic acid (HR: 0.56, p = 0.001). Additionally, ECOG PS and the number of metastatic bone sites were identified as independent prognostic factors for time to the first SRE. The safety profile was consistent with previous studies reported in the literature. Conclusions: Our study demonstrated that when used with CDK4/6 inhibitors, denosumab is associated with a delay in SREs and a lower SRE incidence than zoledronic acid in patients with bone metastases. These findings support the efficacy of denosumab in preventing SREs and suggest that CDK4/6 inhibitors may have distinct effects on the bone microenvironment, particularly when combined with denosumab.

High Fracture Risk of Femoral Bone Metastasis Treated with Palliative Radiotherapy in Recent Years

Bone-modifying agents (BMAs) have been widely used to reduce skeletal-related events, including pathological fractures. Herein, we aimed to clarify the incidence of pathological fractures caused by high-risk femoral bone metastases after palliative radiotherapy (RT) in the BMA era and evaluate the necessity of prophylactic surgical stabilization. We assessed 90 patients with high-risk femoral bone metastases, indicated by Mirels' scores ≥ 8, without pathological fractures and surgical fixations, who received palliative RT at our institution between January 2009 and December 2018. Pathological fracture incidence was analyzed using the Kaplan-Meier method and was 22.8% and 31.0% at 2 and 6 months, respectively. Pathological fractures were caused by 17 of 65 lesions (26.2%) and 9 of 25 lesions (36.0%) in patients who received BMAs and those who did not, respectively (p = 0.44). Additionally, 17 of 42 lesions (40.5%) and 9 of 48 lesions (18.8%) with axial cortical involvement ≥30 and <30 mm, respectively, caused pathological fractures (p = 0.02). The incidence of pathological fractures was high among patients with high-risk femoral bone metastases treated with palliative RT, particularly those with axial cortical involvement ≥30 mm. Therefore, aggressive indications for prophylactic surgical stabilization are warranted for high-risk femoral metastases despite BMA administration.

Review on effects and mechanisms of plant-derived natural products against breast cancer bone metastasis

Bone metastasis is the prevalent form of metastasis in breast cancer, resulting in severe pain, pathological fractures, nerve compression, hypercalcemia, and other complications that significantly impair patients' quality of life. The infiltration and colonization of breast cancer (BC) cells in bone tissue disrupt the delicate balance between osteoblasts and osteoclasts within the bone microenvironment, initiating a vicious cycle of bone metastasis. Once bone metastasis occurs, conventional medical therapy with bone-modifying agents is commonly used to alleviate bone-related complications and improve patients' quality of life. However, the utilization of bone-modifying agents may cause severe drug-related adverse effects. Plant-derived natural products such as terpenoids, alkaloids, coumarins, and phenols have anti-tumor, anti-inflammatory, and anti-angiogenic pharmacological properties with minimal side effects. Certain natural products that exhibit both anti-breast cancer and anti-bone metastasis effects are potential therapeutic agents for breast cancer bone metastasis (BCBM). This article reviewed the effects of plant-derived natural products against BCBM and their mechanisms to provide a reference for the research and development of drugs related to BCBM.

Clinical practice guidelines for full-cycle standardized management of bone health in breast cancer patients

Bone health management for breast cancer spans the entire cycle of patient care, including the prevention and treatment of bone loss caused by early breast cancer treatment, the adjuvant application of bone-modifying agents to improve prognosis, and the diagnosis and treatment of advanced bone metastases. Making good bone health management means formulating appropriate treatment strategies and dealing with adverse drug reactions, and will help to improve patients' quality of life and survival rates. The Breast Cancer Expert Committee of the National Cancer Center for Quality Control organized relevant experts to conduct an in-depth discussion on the full-cycle management of breast cancer bone health based on evidence-based medicine, and put forward reasonable suggestions to guide clinicians to better deal with health issues in bone health clinics.

Importance of Whole-Body Scintigraphy or Positron Emission Tomography for Early Detection of Femoral Lesions in Breast Cancer Patients Treated with Bisphosphonates

Background

We hypothesized that most of the atypical femoral fractures (AFFs) associated with bisphosphonate treatment for breast cancer (BC) could be found before the fracture event in another radiological examination already performed by breast surgeons, rather than on simple radiographs (SRs).

Methods

We thoroughly inspected the clinical charts of BC patients treated at our institute between 2008 and 2017. In total, 228 patients were categorized into three groups based on SRs: complete AFF on at least one side (group 1); incomplete fracture on at least one side, but not any complete fracture (group 2); and no suspicious lesion (group X) on either femur. Then, we inspected whole-body scintigraphy (WBS) and positron emission tomography (PET)-computed tomography (CT) images in all groups. For group X, patients with radiological clues from at least one femur were categorized, ultimately, into final group 3 and the rest made up the normal group.

Results

About 35% of the patients showed AFFs (complete or incomplete) or suspicious lesions as AFFs, associated with the side effect of Bisphosphonate. In group 1, bilateral lesions (complete or incomplete fractures) were more frequently seen on SRs than unilateral lesions (p = 0.008). The initially identified findings in WBS and PET-CT for the respective complete and incomplete fractures on SRs of groups 1 and 2 were seen at a mean of 7 months previously. SRs did not reveal the lesions in group 3 until 5 months after the initial identification of the lesions in WBS and PET-CT.

Conclusions

Even before incomplete AFFs were detectable on SRs, they could be found at check-ups using WBS and PET-CT that had been previously examined by breast surgeons and radiologists for metastasis surveillance. Awareness of the lesions creates an opportunity for prophylactic surgery before complete fractures occur.

Multicenter study on atypical femoral fractures in patients with bone metastases taking bone- modifying agents

Bone-modifying agents (BMAs), with bone-resorptive inhibitory effects, such as zoledronic acid and denosumab, are widely used at higher doses for bone-related events caused by bone metastasis of malignant tumors. These drugs have been suggested to be associated with atypical femoral fractures (AFFs), and the relationship between BMAs and AFFs has attracted attention. To investigate the clinical features including bone union time of AFFs in patients administered BMA for bone metastasis, we conducted a retrospective multicenter study. Thirty AFFs from 19 patients were enrolled in this study. Thirteen patients had bilateral AFFs, and nineteen AFFs had prodromal symptoms. Eighteen AFFs underwent surgery after complete fracture, three failed to achieve bone union and required nonunion surgery, and 11 AFFs that achieved bone union had an average period until bone union of 16.2 months, which was much longer than that previously reported for ordinary AFFs. Seven patients discontinued the BMAs, but not due to AFFs. Stopping BMAs in patients with bone metastasis would make it difficult to secure their performance of activities of daily living, and AFF with BMA administration might require a longer time for union. Therefore, it would be important to prevent incomplete AFF from becoming complete AFF via prophylactic internal fixation.

Computed tomography density changes of bone metastases after concomitant denosumab

OBJECTIVE

To evaluate bone density changes at the level of normal trabecular bone and bone metastases (BMs) after denosumab (DM) treatment in oncologic patients.

MATERIALS AND METHODS

We retrospectively evaluated 31 consecutive adult patients with histologically confirmed solid tumors with at least one newly diagnosed bone metastatic lesion detected at CT. Patients received treatment with DM, 120 mg subcutaneous every 28 days for at least 6 months. Bone density was determined at the level of BMs and at the level of normal trabecular bone of lumbar vertebrae using a region of interest (ROI)-based approach.

RESULTS

A progressive increase in CT bone density was demonstrated at the level of normal trabecular bone at 6 months (18% ± 5%) and 12 months (23% ± 7%) after the treatment begins. BMs showed a significant increase in CT bone density (p < 0.05) as compared to baseline after 6 months (57% ± 15%) and 12 months (1.06 ± 0.25 times higher) after treatment.

CONCLUSION

We have found that long-term treatment with DM increases bone density progressively in oncologic patients. This effect can be observed not only at the level of secondary lesions but also at the level of apparently normal trabecular bone and is more pronounced for osteolytic metastases.

AAOS Clinical Practice Guideline Summary: Treatment of Metastatic Carcinoma and Myeloma of the Femur

The Musculoskeletal Tumor Society, in partnership with American Society of Clinical Oncology and American Society for Radiation Oncology, has developed a clinical practice guideline to assist providers with the care of patients with metastatic carcinoma and myeloma of the femur. The guideline was developed by an Expert Panel consisting of representatives of all three organizations by American Academy of Orthopaedic Surgeons (AAOS) methodologists using the AAOS standardized guideline development process. A systematic review of the available evidence was conducted, and the identified evidence was rated was rated for quality and potential for bias. Recommendations were developed based on this evidence in a standardized fashion. The guideline was approved by the guideline approval bodies of all three organizations. Thirteen recommendations were synthesized covering relevant subtopics such as imaging, use of bone-modifying agents, radiation therapy, and surgical reconstruction. The consensus of the expert panel was that bone-modifying agents may assist in reducing the incidence of femur fracture, regardless of tumor histology. The panel recommended the use of radiation therapy to decrease the rate of femur fractures for patients considered at increased risk. The panel recommended arthroplasty be considered to improve patient function and decrease the need of postoperative radiation therapy in patients with pathologic fractures in the femur.

The use of bone-modifying agents in multiple myeloma

Multiple myeloma is a hematological neoplasm characterized by abnormal proliferation of plasma cells in the bone marrow and is usually associated with increased bone pain and skeletal-related events such as pathological fracture and/or spinal cord compression. Myeloma bone disease results in changes in the bone-marrow microenvironment evidenced by increased osteoclastic activity and/or decreased osteoblastic activity, which negatively affect quality of life. Treatment of myeloma bone disease includes bisphosphonates or denosumab (bone-modifying agents). These agents do not induce the formation of new bone or repair existing bone damage, but they can decrease bone pain and the risk of pathological fracture. While these agents improve quality of life, it is not known whether they improve overall survival. This review focuses on different classes of bone-modifying agents, their mechanisms of action, time of initiation, duration of therapy, and potential survival benefits.

Association of adenosine signaling gene signature with estrogen receptor-positive breast and prostate cancer bone metastasis

Bone metastasis is a common and devastating consequence of several major cancer types, including breast and prostate. Osteocytes are the predominant bone cell, and through connexin (Cx) 43 hemichannels release ATP to the bone microenvironment that can be hydrolyzed to adenosine. Here, we investigated how genes related to ATP paracrine signaling are involved in two common bone-metastasizing malignancies, estrogen receptor positive (ER⁺) breast and prostate cancers. Compared to other sites, bone metastases of both cancer types expressed higher levels of ENTPD1 and NT5E, which encode CD39 and CD73, respectively, and hydrolyze ATP to adenosine. ADORA3, encoding the adenosine A3 receptor, had a similar expression pattern. In primary ER⁺ breast cancer, high levels of the triplet ENTPD1/NT5E/ADORA3 expression signature was correlated with lower overall, distant metastasis-free, and progression-free survival. In ER⁺ bone metastasis biopsies, this expression signature is associated with lower survival. This expression signature was also higher in bone-metastasizing primary prostate cancers than in those that caused other tumor events or did not lead to progressive disease. In 3D culture, a non-hydrolyzable ATP analog inhibited the growth of breast and prostate cancer cell lines more than ATP did. A3 inhibition also reduced spheroid growth. Large-scale screens by the Drug Repurposing Hub found ER⁺ breast cancer cell lines were uniquely sensitive to adenosine receptor antagonists. Together, these data suggest a vital role for extracellular ATP degradation and adenosine receptor signaling in cancer bone metastasis, and this study provides potential diagnostic means for bone metastasis and specific targets for treatment and prevention.

Functionalized Selenium Nanotherapeutics Synergizes With Zoledronic Acid to Suppress Prostate Cancer Cell Growth Through Induction of Mitochondria-Mediated Apoptosis and Cell Cycle S Phase Arrest

The use of established drugs in new therapeutic applications has great potential for the treatment of cancers. Nanomedicine has the advantages of efficient cellular uptake and specific cell targeting. In this study, we investigate using lentinan-functionalized selenium nanoparticles (LET-SeNPs) for the treatment of prostate cancer (PCa). We used assays to demonstrate that a combination of LET-SeNPs and zoledronic acid (ZOL) can reduce PCa cell viability in vitro. Stability and hemocompatibility assays were used to determine the safety of the combination of LET-SeNPs and ZOL. The localization of LET-SeNPs was confirmed using fluorescence microscopy. JC-1 was used to measure the mitochondrial membrane potential, while the cellular uptake, cell cycle and apoptosis were evaluated by flow cytometry. Finally, cell migration and invasion assays were used to evaluate the effects of the combination treatment on cell migration and invasion. Under optimized conditions, we found that LET-SeNPs has good stability. The combination of LET-SeNPs and ZOL can effectively inhibit metastatic PCa cells in a concentration-dependent manner, as evidenced by cytotoxicity testing, flow cytometric analysis, and mitochondria functional test. The enhanced anti-cancer effect of LET-SeNPs and ZOL may be related to the regulation of BCL2 family proteins that could result in the release of cytochrome C from the inner membranes of mitochondria into the cytosol, accompanied by induction of cell cycle arrest at the S phase, leading to irreversible DNA damage and killing of PCa cells. Collectively, the results of this study suggest that the combination of SeNPs and ZOL can successfully inhibit the growth of PCa cells.

Risk factors for atypical forearm fractures associated with bisphosphonate usage

BACKGROUND

The purpose of this study was to find the diagnostic factors for atypical forearm fractures additional to atypical femur fractures, via a retrospective case-control study. Thus, our authors performed a complete enumeration survey for patients under the treatment of bisphosphonate (BP).

METHODS

We identified 53 patients that met the following inclusion criteria between March 2009 and February 2019: a BP therapy history or ongoing administration of at least 1 year, presence of simple radiographs of bilateral femurs and forearms, and availability of complete medical records and radiological data. The patients were divided into two groups: those with any lesion of atypical fractures of ulna or radius, regardless of the displacement of at least one side extremity in simple radiographs (group 1, 20 patients); and those without any lesions of pathognomonic finding or fractures in either forearm in simple radiographs (group 2, 33 patients).

RESULTS

Univariate analyses of basic demographic characteristic such as age, smoking, comorbidity of diabetes mellitus or any connective tissue disease needing steroid treatment, and BMD showed no significant differences between the groups (P > 0.05). The co-morbidity of malignant cancer inevitably needing BP usage was not different between the two groups. Multivariate analyses of the several variables that differed significantly between the two groups in univariate analyses demonstrated that total period and single prescribing physician/surgeon were significantly associated with forearm fractures. A cut-off value of 65 months for the total period predicted the presence atypical forearm fractures.

CONCLUSIONS

Atypical forearm fractures are probably more common than reported in the literature to date, and all forearm lesions were accompanied by preceding atypical femur fractures. The period of BP administration had the main effect on the occurrence of atypical forearm fractures, particularly if more than 65 months. Also, the prescription by multiple physician was predicting factor for forearms lesion additionally to AFFs, however, more evidence-based study is needed to understand the effects of cancer-related BP usage on the forearm.

LEVEL OF EVIDENCE

Level III, retrospective case-control study.

Tooth extraction in mice administered zoledronate increases inflammatory cytokine levels and promotes osteonecrosis of the jaw

INTRODUCTION

Osteonecrosis of the jaw (ONJ) occurring after invasive dental treatment often adversely affects patients' activities of daily living. Long-term administration of strong anti-bone resorptive agents such as bisphosphonates prior to invasive dental treatment is considered an ONJ risk factor; however, pathological mechanisms underlying ONJ development remain unclear.

MATERIALS AND METHODS

We developed an ONJ mouse model in which a tooth is extracted during treatment with the bisphosphonate zoledronate.

RESULTS

We observed induction of apoptosis in osteocytes, resulting in formation of empty lacunae in jaw bones at sites of tooth extraction but not in other bones of the same mice. We also observed elevated levels of inflammatory cytokines such as TNFα, IL-6 and IL-1 in jaw bone at the extraction site relative to other sites in zoledronate-treated mice. We also report that treatment in vitro with either zoledronate or an extract from Porphyromonas gingivalis, an oral bacteria, promotes expression of inflammatory cytokines in osteoclast progenitor cells. We demonstrate that gene-targeting of either TNFα, IL-6 or IL-1 or treatment with etanercept, a TNFα inhibitor, or a neutralizing antibody against IL-6 can antagonize ONJ development caused by combined tooth extraction and zoledronate treatment.

CONCLUSIONS

Taken together, the cytokine storm induced by invasive dental treatment under bisphosphonate treatment promotes ONJ development due to elevated levels of inflammatory cytokine-producing cells. Our work identifies novel targets potentially useful to prevent ONJ.

Practical consensus recommendaton for adjuvant bone-modifying agents in breast cancer

Bone-modifying therapy is a primary research interest in breast cancer. Several features contribute to the importance of the bone environment in the management of breast cancer. Firstly, bone metastases represent the most common site of breast cancer metastases and secondly, the emergence of cancer treatment-induced bone loss (CTIBL) among breast cancer survivors and patients is of increasing concern. In the adjuvant setting, bisphosphonates can be given to prevent and treat tumor therapy-induced bone loss in premenopausal and postmenopausal women and, owing to their beneficial effect on bone turnover, have also been evaluated for prevention of bone metastases occurrence. Expert oncologists discusses on the update on the approaches of Bone-modifying Agents and its treatment options. This expert group used data from published literature, practical experience and opinion of a large group of academic oncologists to arrive at this practical consensus recommendations for the benefit of community oncologists.

Study of Adverse Effect Profile of Zoledronic Acid Infusion Among Patients with Cancer: A Retrospective Analysis

Background: Zoledronic acid (ZA) is widely used in the management of cancer-related bone events. It, however, might be associated with serious adverse effects. Objectives: To evaluate ZA adverse effects and changes in biochemical parameters related to ZA toxicities among patients with cancer. Methods: Ninety-eight oncology patients, who were prescribed ZA intravenous (IV) infusion, were interviewed to assess whether they experienced ZA related symptoms, including acute events and serious adverse effects. ZA’s effects on the serum levels of different biochemical parameters were retrospectively assessed by checking patients’ electronic medical records. Results: The most commonly reported adverse effects were: myalgia (48%), bone pain (36.7%), influenza-like symptoms (34.7%), headache (31.6%), and pyrexia (22.45%) with decreasing frequency of such adverse effects upon repeated infusions. Serious side effects including jaw osteonecrosis, cardiac, and renal problems were not reported. A small, but statistically significant reduction in serum calcium, creatinine, and total protein levels was observed upon comparing levels before and after the first IV infusion of ZA (P ≤ 0.031). No significant change was recorded with other serum electrolytes including phosphorus, sodium, potassium, and magnesium as well as urea levels (P ≥ 0.271). No significant difference was determined in terms of final serum levels of all parameters in comparison to pre-treatment (P ≥ 0.059), except for potassium, where a significant reduction was observed (P = 0.003). Notably, the mean values of all parameters were within the normal range. Conclusions: ZA acute events resolved with symptomatic treatment and reduced with repeated IV infusions. ZA appears as a safe treatment modality for skeletal-related events among patients with cancer and the reported adverse effects should not affect patients’ compliance.

Osteoclast Fusion: Physiological Regulation of Multinucleation through Heterogeneity-Potential Implications for Drug Sensitivity

Classically, osteoclast fusion consists of four basic steps: (1) attraction/migration, (2) recognition, (3) cell-cell adhesion, and (4) membrane fusion. In theory, this sounds like a straightforward simple linear process. However, it is not. Osteoclast fusion has to take place in a well-coordinated manner-something that is not simple. In vivo, the complex regulation of osteoclast formation takes place within the bone marrow-in time and space. The present review will focus on considering osteoclast fusion in the context of physiology and pathology. Special attention is given to: (1) regulation of osteoclast fusion in vivo, (2) heterogeneity of osteoclast fusion partners, (3) regulation of multi-nucleation, (4) implications for physiology and pathology, and (5) implications for drug sensitivity and side effects. The review will emphasize that more attention should be given to the human in vivo reality when interpreting the impact of in vitro and animal studies. This should be done in order to improve our understanding of human physiology and pathology, as well as to improve anti-resorptive treatment and reduce side effects.

Identification of Drug Candidates for Breast Cancer Therapy Through Scaffold Repurposing: A Brief Review

Conventional drug discovery is a time consuming and expensive expedition with less clinical preference achievement proportion intended for breast cancer therapy. Even if numerous novel approaches to the conformation of drugs have been introduced for breast cancer therapy, they are yet to be implemented in clinical practice. This tempting strategy facilitates a remarkable chance to take the entire benefit of existing drugs. Despite drug repurposing significantly decrease the investigational period and cost, it has got many objections and issues. Scaffold repurposing is an approach that procures a novel significance on the decrepit motto of "to commencement with a pristine drug" . Hence, we move into a probable and nearer approach, the exploitation of scaffolds, which was originally developed for other purposes, including anti-tumor activity. In this review, we summarize different drugs and scaffolds used in breast cancer therapy.

Bone metastasis and skeletal-related events in patients with solid cancer: A Korean nationwide health insurance database study

Bone is one of the most common sites of metastasis from advanced solid tumors. Bone metastasis is a leading cause of pain and increases the risk of skeletal-related events (SREs) in cancer patients. In addition to affecting the quality of life, it also increases the medical costs and mortality risk. We aimed to examine the occurrence of bone metastasis and SREs in Korean cancer patients using a nationwide health database. Using claims data from the National Health Insurance Service-National Sample Cohort (2002–2013), we extracted the data of bone metastasis patients diagnosed with any of the seven major cancers in Korea from January 2002 to December 2010. Selected SREs included pathologic fracture, spinal cord compression, radiation therapy, and palliative bone surgery. We used time-to-event analysis to estimate patient survival after bone metastasis. A total of 21,562 newly diagnosed cancer patients were identified; bone metastases developed in 1,849 patients (breast cancer, 18.8%; prostate cancer, 17.5%; lung cancer, 13.7%). The median time from primary cancer diagnosis to bone metastasis was 18.9 months. The cumulative incidence of SREs was 45.1% in all bone metastasis patients. The most common cancer type was lung cancer (53.4%), followed by liver (50.9%), prostate (45.9%), breast (43.6%), and colorectal (40.2%) cancers. Almost all SREs developed 1 month after bone metastasis, except in patients with breast and prostate cancers (median: 5.9 months in breast cancer and 4.7 months in prostate cancer). Survival duration after the development of bone metastasis was < 6 months in stomach, liver, colorectal, and lung cancer patients. Breast and prostate cancer patients survived for > 1 year after the occurrence of SREs. This study reveals the epidemiology of bone metastasis and SREs in Korean cancer patients, and the findings can be used to assess the actual bone health status of cancer patients.

Radiation therapy combined with bone-modifying agents ameliorates local control of osteolytic bone metastases in breast cancer

Bone-modifying agents (BMAs) are frequently used for the treatment of bone metastases. Both BMA and radiation therapy (RT) are effective; however, there are few studies that have evaluated the efficacy of the combination treatment. We evaluated the effectiveness of RT + BMA in breast cancer-induced osteolytic bone metastasis as compared to BMA alone. A total of 43 lesions in 25 patients were evaluated. The median follow-up period was 18 (range, 2-90) months. None of the lesions was treated with chemotherapy or molecular targeted drugs during the follow-up period for evaluating the local response. Patients with complete or partial response were considered as responders, while those with stable or progressive disease were considered as non-responders. The rate of response with RT + BMA was significantly higher than that with BMA alone (P = 0.001). The cumulative incidence rate of response at 6 months was 54.4% in the RT + BMA group and 27.5% in the BMA alone group. The median time to response was 4 (range, 2-11) months in the RT + BMA group and 6 (range, 4-16) months in the BMA alone group. The overall survival rate in the responder group (83.1% at 1 year) was significantly higher than that in the non-responder group (37.5% at 1 year) (P = 0.029). In conclusion, RT combined with BMA was found to be more effective than BMA alone for the treatment of osteolytic bone metastasis, which thereby improves the prognosis.

Utility of urinary type I collagen cross-linked N-telopeptide as a prognostic indicator in breast cancer patients with bone metastases

BACKGROUND

Breast cancer patients with bone metastases are usually managed with bone modifying agents, such as zoledronic acid and denosumab, and some bone turnover markers (BTMs) have been recognized as prognostic indicators in such patients. Although several studies have demonstrated the validity of BTMs as prognostic markers in patients treated with zoledronic acid, few studies have reported the utility of BTMs with denosumab treatment. In this study, we evaluated whether urinary N-telopeptide of type I collagen (u-NTX) can be a prognostic indicator in patients treated with denosumab.

METHODS

Thirty-six breast cancer patients newly diagnosed with bone metastases were evaluated retrospectively. Patients were treated with denosumab and anti-cancer drugs. u-NTX levels were measured 1 month before and after administration of denosumab, and the ratio of u-NTX levels before and after denosumab (change ratio) was assessed for its association with prognosis.

RESULTS

Levels of u-NTX decreased after denosumab administration in all patients except for one. The median value of the u-NTX change ratio was 0.766. Based on the change ratio, patients were divided into either a "high group" (n = 18) or a "low group" (n = 18). The low group showed significantly shorter overall survival (OS) compared with the high group (low group 15.0 months; high group 54.0 months; P = 0.012). Multivariate analysis indicated that the "low group" was an independent prognostic factor for OS (P = 0.028).

CONCLUSION

We demonstrated that the u-NTX change ratio in denosumab-treated breast cancer patients with bone metastases can be a prognostic marker.

Breast Cancer, Version 3.2020, NCCN Clinical Practice Guidelines in Oncology

Several new systemic therapy options have become available for patients with metastatic breast cancer, which have led to improvements in survival. In addition to patient and clinical factors, the treatment selection primarily depends on the tumor biology (hormone-receptor status and HER2-status). The NCCN Guidelines specific to the workup and treatment of patients with recurrent/stage IV breast cancer are discussed in this article.

Management of bone metastasis with intravenous bisphosphonates in breast cancer: a systematic review and meta-analysis of dosing frequency

BACKGROUND

Bisphosphonates are wildly used in breast cancer patients with bone metastasis and generally administrated every 4 weeks to lessen the risk of subsequent skeletal-related events. Bisphosphonates administration every 12 weeks is also recommended in some guidelines. Recent clinical trials suggested that bisphosphonate treatment with reduced frequency (every 12 weeks) to be non-inferior to standard therapy. The object of this analysis was to contrast the efficacy and safety of these two treatment strategies.

METHOD

We systematically retrieved databases such as MEDLINE, PubMed, Embase, and Cochrane library from 1947 to present for clinical trials comparing the efficacy between standard (every 4 weeks) and de-escalation (every 12 weeks) treatment of bisphosphates.

RESULTS

We identified 4 articles with available data from 4 randomized clinical trials (n = 1721). Administration of bisphosphate every 12 weeks was non-inferior to administration every 4 weeks. There existed no significant difference in on-study skeletal-related events, renal dysfunction, and osteonecrosis of jaw. In the exploratory study, patients who received intravenous bisphosphates before enrollment experienced less on-study skeletal-related events and significant difference was observed between groups.

CONCLUSION

This analysis suggested that de-escalation treatment with bisphosphates may be superior to standard treatment in terms of efficacy, safety, and economic costs. But it would be better that all the patients receive bisphosphates every 4 weeks for several months before de-escalation.

Atypical femoral fracture in patients with bone metastasis receiving denosumab therapy: a retrospective study and systematic review

BACKGROUND

While denosumab has been shown to prevent skeletal-related events in patients with bone metastasis, there is a concern that it may cause atypical femoral fracture (AFF). While AFF has been reported in patients with osteoporosis receiving denosumab, data are scarce in the context of AFF occurring in patients with bone metastasis receiving monthly denosumab therapy.

METHODS

To analyze the incidence of AFF in patients with bone metastasis, we reviewed the medical records of patients who had received monthly denosumab (120 mg) treatment from May 2012 to June 2017 at any of the three participant institutions.

RESULTS

The study population consisted of 277 patients who had received a median of 10 doses (range, 1-79) of denosumab. Five patients were diagnosed as having AFF or symptomatic atypical femoral stress reaction (AFSR) needing surgical intervention, representing an incidence rate of 1.8% (95% confidence interval, 0.77-4.2). These patients had received 15, 45, 45, 46 or 47 doses of denosumab, respectively. Four of the patients had received prior zoledronic acid treatment. The results of our analysis suggested that long-term use of denosumab, especially for more than 3.5 years, and prior use of zoledronic acid were risk factors for the development of AFF.

CONCLUSIONS

We found the AFF events in 5 patients (1.8%) among 277 cancer patients who had received monthly denosumab (120 mg) treatment. Long-term denosumab treatment and prior zoledronic acid treatment were identified as risk factors for the development of AFF.

The Bone Extracellular Matrix as an Ideal Milieu for Cancer Cell Metastases

Bone is a preferential site for cancer metastases, including multiple myeloma, prostate, and breast cancers.The composition of bone, especially the extracellular matrix (ECM), make it an attractive site for cancer cell colonization and survival. The bone ECM is composed of living cells embedded within a matrix composed of both organic and inorganic components. Among the organic components, type I collagen provides the tensile strength of bone. Inorganic components, including hydroxyapatite crystals, are an integral component of bone and provide bone with its rigidity. Under normal circumstances, two of the main cell types in bone, the osteoblasts and osteoclasts, help to maintain bone homeostasis and remodeling through cellular communication and response to biophysical signals from the ECM. However, under pathological conditions, including osteoporosis and cancer, bone remodeling is dysregulated. Once in the bone matrix, disseminated tumor cells utilize normal products of bone remodeling, such as collagen type I, to fuel cancer cell proliferation and lesion outgrowth. Models to study the complex interactions between the bone matrix and metastatic cancer cells are limited. Advances in understanding the interactions between the bone ECM and bone metastatic cancer cells are necessary in order to both regulate and prevent metastatic cancer cell growth in bone.

The incidence and relative risk of adverse events in patients treated with bisphosphonate therapy for breast cancer: a systematic review and meta-analysis

Background:

Adjuvant bisphosphonates reduce the rate of breast cancer recurrence in the bone and improve breast cancer survival. However, the risk of adverse events associated with bisphosphonate therapy for breast cancer remains poorly defined.

Methods:

A literature search was conducted using the PubMed, EMBASE, Cochrane and Web of Science libraries. Risk ratio (RR) was calculated to evaluate the adverse events of the meta-analytic results. Osteonecrosis of the jaw (ONJ) incidence was calculated using the random effect model (D+L pooled) for meta-analysis.

Results:

A total of 47 studies comprising 20,607 patients were included; 23 randomized controlled studies (RCTs) provided data of adverse events for bisphosphonate therapy versus without bisphosphonates. Bisphosphonates were significantly associated with influenza-like illness (RR = 4.52), fatigue (RR = 1.08), fever (RR = 1.82), dyspepsia (RR = 1.25), anorexia (RR = 1.29), and urinary tract infection (RR = 1.32). No differences were observed in other adverse events. We combined the incidence of ONJ in 24 retrospective studies to analyze the incidence of ONJ using bisphosphonates. The pooled probability of ONJ toxicity in the bisphosphonates group was 2%.

Conclusions:

Bisphosphonates were significantly associated with influenza-like illness, fatigue, fever, dyspepsia, anorexia, and urinary tract infection. Furthermore, bisphosphonates increase the risk of ONJ toxicity.

Management of bone health in solid tumours: From bisphosphonates to a monoclonal antibody

Patients with solid tumours are at risk of impaired bone health from metastases and cancer therapy-induced bone loss (CTIBL). We review medical management of bone health in patients with solid tumours over the past 30 years, from first-generation bisphosphonates to the receptor activator of nuclear factor κB ligand (RANKL)-targeted monoclonal antibody, denosumab. In the 1980s, first-generation bisphosphonates were shown to reduce the incidence of skeletal-related events (SREs) in patients with breast cancer. Subsequently, more potent second- and third-generation bisphosphonates were developed, particularly zoledronic acid (ZA). Head-to-head studies showed that ZA was significantly more effective than pamidronate for reducing SREs in patients with breast and castrate-resistant prostate cancer (CRPC), becoming the standard of care for more than a decade. The RANKL inhibitor denosumab was licensed in 2010, and head-to-head studies and integrated analyses confirmed its superiority to ZA for preventing SREs, particularly in breast cancer and CRPC. Bisphosphonates and denosumab have also been investigated for prevention of CTIBL in patients receiving hormonal therapy for breast and prostate cancer, and denosumab is licensed in this indication. Despite advances in management of bone health, several issues remain, notably the optimal time to initiate therapy, duration of therapy, and dosing frequency, and how to avoid toxicity, particularly with long-term treatment. In summary, introduction of ZA and denosumab has protected patients with bone metastasis from serious bone complications and improved their quality of life. Ongoing research will hopefully guide the optimal use of these agents to help maintain bone health in patients with solid tumours.

Bone-targeted agent treatment patterns and the impact of bone metastases on patients with advanced breast cancer in the United States

OBJECTIVE

Bone metastases are common among patients with advanced breast cancer, putting patients at increased risk of skeletal-related events (SREs). This study described impact of bone metastases, utilization of bone-targeted agents (BTAs) and physicians' decision processes for BTA use in advanced breast cancer.

METHODS

Data were collected using the Adelphi Breast Cancer Disease-Specific Programme in the United States. Physicians completed a detailed record for eligible patients (women ≥18 years, with stage IIIB-IV breast cancer).

RESULTS

Data available from 1276 patients with advanced breast cancer included 485 (38%) with bone metastases. Most (80%) reported pain at bone metastasis diagnosis; of those reporting pain, 55% reported moderate to severe pain. Among patients with bone metastasis, 69% received a BTA. Reasons for initiating BTAs were bone pain (32%) and an estimated high risk of SREs (25%). Reasons for not treating with BTAs were very recent diagnosis (37%), poor Karnofsky performance status (14%), perceived low risk of SREs (11%) and short life expectancy (11%). Zoledronic acid (48%) and denosumab (42%) were commonly used BTAs; the main reasons for initiating BTA treatment were long-term safety (28% and 32%, respectively) and efficacy in delaying SREs (15% and 31%, respectively). The analysis was not adjusted for age or other possible confounders.

CONCLUSION

Bone pain is a common and sometimes severe symptom of bone metastases in advanced breast cancer and a common reason for initiating BTA treatment. Safety and efficacy were the main factors considered by physicians when selecting BTAs.

The history of cancer pain and bone-targeted agents: 10 most commonly asked questions

The prevalence of pain and skeletal complications of metastatic bone disease is high and an important factor, which contributes to decreased quality of life and low survival rate. Bone-targeted agents are well-established therapies to reduce the skeletal-related events in patients with bone metastasis. However, the analgesic effect of these medications is still controversial. The objective of this review is to summarize the existing evidence about the use of bone-targeted agents in the treatment of metastatic bone pain, trying to answer to the 10 most commonly asked questions in this matter. To achieve this goal, authors did a research of reviews published between January 2001 and January 2018, using the terms MeSH: “cancer pain” and bisphosphonates. The source used was the PubMed (NLM) database. The search yielded 36 reviews, but only 16 met the inclusion criteria. Even with the introduction of a new class of drugs, bisphosphonates and specially zoledronic acid are the most commonly used drugs in most oncology centers. Bisphosphonates and denosumab appear to be beneficial in preventing skeletal morbidity but their analgesic role and impact on quality of life and survival are not so well established.

Systematic review: Incidence, risk factors, survival and treatment of bone metastases from colorectal cancer

Background

Bones are not considered a frequent metastatic site in patients with colorectal cancer (CRC). The purpose of the present study was to determine the incidence of bone metastases (BM) in CRC, to identify possible risk factors for BM, survival after BM, and effect of treatment of BM including antiresorptive treatment.

Material and methods

A computer-based literature search was carried out using PubMed and EMBASE.

Results

We included 29 studies. One randomized placebo controlled trial (RCT) study, two autopsy studies, five register studies, and twenty retrospective cohort studies. The studies described different cohorts making direct comparison difficult. Three studies analysed the effect of different treatments for BM including one RCT study.

Conclusion

The incidence of bone metastases was 3–7% in patients with CRC, and it was not possible to detect an increase in incidence over time. The most well established risk factors for BM are rectal cancer, having lymph node invasion at surgery of primary tumor, and lung metastases at any time. Other risk factors such as RAS mutation status have been suggested but results are not conclusive. Survival ranges from 5 to 21 months after diagnosis of BM depending on cohort, with survival of about 8 months in unselected patients. Several variables have been suggested as potential prognostic markers but are all poorly investigated. Treatment of BM is not well investigated, though patients seem to benefit from bisphosphonate treatment with regard to lower risk of skeletal related events. This review highlights the need for new research in the area.

An update on the currently available and future chemotherapy for treating bone metastases in breast cancer patients

INTRODUCTION

Bone metastases in breast cancer patients are a common clinical problem. Many factors influence the treatment decision, including tumor characteristics, previous treatment and tumor burden in the treatment of metastatic breast cancer.

AREAS COVERED

This present review summarizes the new treatment strategies and the chemotherapeutic agents currently available in the management of metastatic breast cancer with bone metastases.

EXPERT OPINION

Patients with bone metastases more often have hormone receptor-positive tumours. Although new treatment agents for metastatic breast cancer have been investigated, endocrine therapy is still considered as the treatment of choice for patients with bone metastases although chemotherapy still has an important place. In recent years, new chemotherapeutic agents such as etirinotecan and nab-paclitaxel have been established though there are few studies that have looked at particular types of metastases. In the last decade, therapies for bone metastasis resistant to endocrine therapy have predominantly focused on radiotherapy, surgical resection, chemotherapy, bone-targeting radiopharmaceuticals and targeted therapeutics. New targeted agents include: Src inhibitors, cathepsin K inhibitors, CXCR4 inhibitors, TGF-B blockade and integrin antagonists while drug delivery systems for chemotherapy have also been developed. These new treatment options could be future treatment options for bone metastatic disease if early promising results are confirmed by clinical trials.

Clinical Usefulness of Bisphosphonates in Oncology: Treatment of Bone Metastases, antitumoral Activity and Effect on Bone Resorption Markers

The present article overviews the role of bisphosphonates for the treatment and prevention of bone metastases and their antiangiogenic effects and antitumoral activity. The skeleton is a frequent and clinically relevant site of metastasis in cancer patients. The major events related to bone metastases include bone pain, bone loss, hypercalcemia, spinal cord compression, and fractures. On the basis of their radiographic features, bone metastases are classified as osteoblastic, osteoclastic, or mixed. The primary goals of treatment of bone metastases are reduction of the risk of pathological fractures and other skeletal-related events, and pain control. Bisphosphonates are used to prevent pathological fractures by inhibition of osteoclasts. Recent studies suggest that bisphosphonates have some direct antitumoral activity, mainly mediated through the blockade of angiogenic pathways. Further clinical studies are needed to determine the optimal treatment duration, timing and schedule of bisphosphonates, assess their role as adjuvant therapy for the prevention of bone metastases, and establish their antiangiogenic activity in association with standard cytotoxic and hormonal drugs for treatment of patients with advanced disease.

Bisphosphonates in multiple myeloma: an updated network meta-analysis

BACKGROUND

Bisphosphonates are specific inhibitors of osteoclastic activity and are used in the treatment of patients with multiple myeloma (MM). While bisphosphonates are shown to be effective in reducing vertebral fractures and pain, their role in improving overall survival (OS) remains unclear. This is an update of a Cochrane review first published in 2002 and previously updated in 2010 and 2012.

OBJECTIVES

To assess the evidence related to benefits and harms associated with use of various types of bisphosphonates (aminobisphosphonates versus non-aminobisphosphonates) in the management of patients with MM. Our primary objective was to determine whether adding bisphosphonates to standard therapy in MM improves OS and progression-free survival (PFS), and decreases skeletal-related morbidity. Our secondary objectives were to determine the effects of bisphosphonates on pain, quality of life, incidence of hypercalcemia, incidence of bisphosphonate-related gastrointestinal toxicities, osteonecrosis of jaw (ONJ) and hypocalcemia.

SEARCH METHODS

We searched MEDLINE, Embase (September 2011 to July 2017) and the CENTRAL (2017, Issue 7) to identify all randomized controlled trial (RCT) in MM up to July 2017 using a combination of text and MeSH terms.

SELECTION CRITERIA

Any randomized controlled trial (RCT) comparing bisphosphonates versus placebo/no treatment/bisphosphonates and observational studies or case reports examining bisphosphonate-related ONJ in patients with MM were eligible for inclusion.

DATA COLLECTION AND ANALYSIS

Two review authors extracted the data. Data were pooled and reported as hazard ratio (HR) or risk ratio (RR) using a random-effects model. We used meta-regression to explore statistical heterogeneity. Network meta-analysis using Bayesian approach was conducted.

MAIN RESULTS

In this update, we included four new studies (601 participants), resulting in a total of 24 included studies.Twenty RCTs compared bisphosphonates with either placebo or no treatment and four RCTs involved another bisphosphonate as a comparator. The 24 included RCTs enrolled 7293 participants. Pooled results showed that there was moderate-quality evidence of a reduction in mortality with on OS from 41% to 31%, but the confidence interval is consistent with a larger reduction and small increase in mortality compared with placebo or no treatment (HR 0.90, 95% CI 0.76 to 1.07; 14 studies; 2706 participants). There was substantial heterogeneity among the included RCTs (I2 = 65%) for OS. To explain this heterogeneity we performed a meta-regression assessing the relationship between bisphosphonate potency and improvement in OS, which found an OS benefit with zoledronate but limited evidence of an effect on PFS. This provided a further rationale for performing a network meta-analyses of the various types of bisphosphonates that were not compared head-to-head in RCTs. Results from network meta-analyses showed evidence of a benefit for OS with zoledronate compared with etidronate (HR 0.56, 95% CI 0.29 to 0.87) and placebo (HR 0.67, 95% CI 0.46 to 0.91). However, there was no evidence for a difference between zoledronate and other bisphosphonates.The effect of bisphosphonates on disease progression (PFS) is uncertain. Based on the HR of 0.75 (95% CI 0.57 to 1.00; seven studies; 908 participants), 47% participants would experience disease progression without treatment compared with between 30% and 47% with bisphosphonates (low-quality evidence). There is probably a similar risk of non-vertebral fractures between treatment groups (RR 1.03, 95% CI 0.68 to 1.56; six studies; 1389 participants; moderate-quality evidence). Pooled analysis demonstrated evidence for a difference favoring bisphosphonates compared with placebo or no treatment on prevention of pathological vertebral fractures (RR 0.74, 95% CI 0.62 to 0.89; seven studies; 1116 participants; moderate-quality evidence) and skeletal-related events (SREs) (RR 0.74, 95% CI 0.63 to 0.88; 10 studies; 2141 participants; moderate-quality evidence). The evidence for less pain with bisphosphonates was of very low quality (RR 0.75, 95% CI 0.60 to 0.95; eight studies; 1281 participants).Bisphosphonates may increase ONJ compared with placebo but the confidence interval is very wide (RR 4.61, 95% CI 0.99 to 21.35; P = 0.05; six studies; 1284 participants; low-quality evidence). The results from the network meta-analysis did not show any evidence for a difference in the incidence of ONJ (eight RCTs, 3746 participants) between bisphosphonates. Data from nine observational studies (1400 participants) reported an incidence of 5% to 51% with combination of pamidronate and zoledronate, 3% to 11% with zoledronate alone, and 0% to 18% with pamidronate alone.The pooled results showed no evidence for a difference in increase in frequency of gastrointestinal symptoms with the use of bisphosphonates compared with placebo or no treatment (RR 1.23, 95% CI 0.95 to 1.59; seven studies; 1829 participants; low-quality evidence).The pooled results showed no evidence for a difference in increase in frequency of hypocalcemia with the use of bisphosphonates compared with placebo or no treatment (RR 2.19, 95% CI 0.49 to 9.74; three studies; 1090 participants; low-quality evidence). The results from network meta-analysis did not show any evidence for differences in the incidence of hypocalcemia, renal dysfunction and gastrointestinal toxicity between the bisphosphonates used.

AUTHORS' CONCLUSIONS

Use of bisphosphonates in participants with MM reduces pathological vertebral fractures, SREs and pain. Bisphosphonates were associated with an increased risk of developing ONJ. For every 1000 participants treated with bisphosphonates, about one patient will suffer from the ONJ. We found no evidence of superiority of any specific aminobisphosphonate (zoledronate, pamidronate or ibandronate) or non-aminobisphosphonate (etidronate or clodronate) for any outcome. However, zoledronate was found to be better than placebo and first-generation bisposphonate (etidronate) in pooled direct and indirect analyses for improving OS and other outcomes such as vertebral fractures. Direct head-to-head trials of the second-generation bisphosphonates are needed to settle the issue if zoledronate is truly the most efficacious bisphosphonate currently used in practice.

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.

Bisphosphonates and other bone agents for breast cancer

BACKGROUND

Bone is the most common site of metastatic disease associated with breast cancer (BC). Bisphosphonates inhibit osteoclast-mediated bone resorption, and novel targeted therapies such as denosumab inhibit other key bone metabolism pathways. We have studied these agents in both early breast cancer and advanced breast cancer settings. This is an update of the review originally published in 2002 and subsequently updated in 2005 and 2012.

OBJECTIVES

To assess the effects of bisphosphonates and other bone agents in addition to anti-cancer treatment: (i) in women with early breast cancer (EBC); (ii) in women with advanced breast cancer without bone metastases (ABC); and (iii) in women with metastatic breast cancer and bone metastases (BCBM).

SEARCH METHODS

In this review update, we searched Cochrane Breast Cancer's Specialised Register, CENTRAL, MEDLINE, Embase, the World Health Organization's International Clinical Trials Registry Platform (WHO ICTRP) and ClinicalTrials.gov on 19 September 2016.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing: (a) one treatment with a bisphosphonate/bone-acting agent with the same treatment without a bisphosphonate/bone-acting agent; (b) treatment with one bisphosphonate versus treatment with a different bisphosphonate; (c) treatment with a bisphosphonate versus another bone-acting agent of a different mechanism of action (e.g. denosumab); and (d) immediate treatment with a bisphosphonate/bone-acting agent versus delayed treatment of the same bisphosphonate/bone-acting agent.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data, and assessed risk of bias and quality of the evidence. The primary outcome measure was bone metastases for EBC and ABC, and a skeletal-related event (SRE) for BCBM. We derived risk ratios (RRs) for dichotomous outcomes and the meta-analyses used random-effects models. Secondary outcomes included overall survival and disease-free survival for EBC; we derived hazard ratios (HRs) for these time-to-event outcomes where possible. We collected toxicity and quality-of-life information. GRADE was used to assess the quality of evidence for the most important outcomes in each treatment setting.

MAIN RESULTS

We included 44 RCTs involving 37,302 women.In women with EBC, bisphosphonates were associated with a reduced risk of bone metastases compared to placebo/no bisphosphonate (RR 0.86, 95% confidence interval (CI) 0.75 to 0.99; P = 0.03, 11 studies; 15,005 women; moderate-quality evidence with no significant heterogeneity). Bisphosphonates provided an overall survival benefit with time-to-event data (HR 0.91, 95% CI 0.83 to 0.99; P = 0.04; 9 studies; 13,949 women; high-quality evidence with evidence of heterogeneity). Subgroup analysis by menopausal status showed a survival benefit from bisphosphonates in postmenopausal women (HR 0.77, 95% CI 0.66 to 0.90; P = 0.001; 4 studies; 6048 women; high-quality evidence with no evidence of heterogeneity) but no survival benefit for premenopausal women (HR 1.03, 95% CI 0.86 to 1.22; P = 0.78; 2 studies; 3501 women; high-quality evidence with no heterogeneity). There was evidence of no effect of bisphosphonates on disease-free survival (HR 0.94, 95% 0.87 to 1.02; P = 0.13; 7 studies; 12,578 women; high-quality evidence with significant heterogeneity present) however subgroup analyses showed a disease-free survival benefit from bisphosphonates in postmenopausal women only (HR 0.82, 95% CI 0.74 to 0.91; P < 0.001; 7 studies; 8314 women; high-quality evidence with no heterogeneity). Bisphosphonates did not significantly reduce the incidence of fractures when compared to placebo/no bisphosphonates (RR 0.77, 95% CI 0.54 to 1.08, P = 0.13, 6 studies, 7602 women; moderate-quality evidence due to wide confidence intervals). We await mature overall survival and disease-free survival results for denosumab trials.In women with ABC without clinically evident bone metastases, there was no evidence of an effect of bisphosphonates on bone metastases (RR 0.96, 95% CI 0.65 to 1.43; P = 0.86; 3 studies; 330 women; moderate-quality evidence with no heterogeneity) or overall survival (RR 0.89, 95% CI 0.73 to 1.09; P = 0.28; 3 studies; 330 women; high-quality evidence with no heterogeneity) compared to placebo/no bisphosphonates however the confidence intervals were wide. One study reported a trend towards an extended period of time without a SRE with bisphosphonate compared to placebo (low-quality evidence). One study reported quality of life and there was no apparent difference in scores between bisphosphonate and placebo (moderate-quality evidence).In women with BCBM, bisphosphonates reduced the SRE risk by 14% (RR 0.86, 95% CI 0.78 to 0.95; P = 0.003; 9 studies; 2810 women; high-quality evidence with evidence of heterogeneity) compared with placebo/no bisphosphonates. This benefit persisted when administering either intravenous or oral bisphosphonates versus placebo. Bisphosphonates delayed the median time to a SRE with a median ratio of 1.43 (95% CI 1.29 to 1.58; P < 0.00001; 9 studies; 2891 women; high-quality evidence with no heterogeneity) and reduced bone pain (in 6 out of 11 studies; moderate-quality evidence) compared to placebo/no bisphosphonate. Treatment with bisphosphonates did not appear to affect overall survival (RR 1.01, 95% CI 0.91 to 1.11; P = 0.85; 7 studies; 1935 women; moderate-quality evidence with significant heterogeneity). Quality-of-life scores were slightly better with bisphosphonates than placebo at comparable time points (in three out of five studies; moderate-quality evidence) however scores decreased during the course of the studies. Denosumab reduced the risk of developing a SRE compared with bisphosphonates by 22% (RR 0.78, 0.72 to 0.85; P < 0.001; 3 studies, 2345 women). One study reported data on overall survival and observed no difference in survival between denosumab and bisphosphonate.Reported toxicities across all settings were generally mild. Osteonecrosis of the jaw was rare, occurring less than 0.5% in the adjuvant setting (high-quality evidence).

AUTHORS' CONCLUSIONS

For women with EBC, bisphosphonates reduce the risk of bone metastases and provide an overall survival benefit compared to placebo or no bisphosphonates. There is preliminary evidence suggestive that bisphosphonates provide an overall survival and disease-free survival benefit in postmenopausal women only when compared to placebo or no bisphosphonate. This was not a planned subgroup for these early trials, and we await the completion of new large clinical trials assessing benefit for postmenopausal women. For women with BCBM, bisphosphonates reduce the risk of developing SREs, delay the median time to an SRE, and appear to reduce bone pain compared to placebo or no bisphosphonate.

Retrospective Review of Atypical Femoral Fracture in Metastatic Bone Disease Patients Receiving Denosumab Therapy

BACKGROUND

Denosumab therapy is used to reduce skeletal-related events in metastatic bone disease (MBD). There have been reports of atypical femoral fracture (AFF) in osteoporotic patients treated with denosumab but none in the context of higher dose and more frequent denosumab therapy for MBD. The goal of this study was to assess the incidence of AFF in MBD.

PATIENTS AND METHODS

We conducted a retrospective review of 253 patients who received a minimum of 12 doses of denosumab at 120 mg each for MBD. To identify patients with asymptomatic atypical stress reactions in the lateral subtrochanteric femur (which precede fractures), we reviewed the skeletal images of 66 patients who had received at least 21 doses of denosumab for AFF features.

RESULTS

These patients received a median of 17 doses, with a median treatment duration of 23 months. There was 1 case of undiagnosed clinical AFF detected after chart review and 2 cases of subclinical atypical femoral stress reaction observed on imaging review after 23 doses of denosumab over 33 months, 28 doses over 27 months, and 21 doses over 21 months, respectively. Scout computed tomography films showed diffuse cortical thickening of diaphysis with localized periosteal reaction of lateral femoral cortex. Bone scan and magnetic resonance imaging scan of 2 patients with stress reactions confirmed the diagnosis.

CONCLUSION

The incidence of clinical AFF in this context is 0.4% (1/253; 95% confidence interval [CI] 0.1%-2.2%), and the incidence of atypical femoral stress reaction based on imaging review is 4.5% (3/66; 95% CI 1.6%-12.5%). Clinicians should be aware of the clinical prodrome (which may or may not be present) and antecedent imaging changes associated with AFF. The Oncologist 2017;22:438-444Implications for Practice: Among patients with metastatic bone disease treated with denosumab, cases of clinical and subclinical atypical femoral fracture (AFF) are rare. The one detected case of clinical fracture went unrecognized despite prodromic symptoms. Clinicians should be aware of (a) the potential prodrome of anterior thigh/groin pain and (b) subclinical imaging changes in the lateral femur, both of which may precede clinical AFF.

SEOM Clinical Guideline for bone metastases from solid tumours (2016)

Bone metastases are common in many advanced solid tumours, being breast, prostate, thyroid, lung, and renal cancer the most prevalent. Bone metastases can produce skeletal-related events (SREs), defined as pathological fracture, spinal cord compression, need of bone irradiation or need of bone surgery, and hypercalcaemia. Patients with bone metastases experience pain, functional impairment and have a negative impact on their quality of life. Several imaging techniques are available for diagnosis of this disease. Bone-targeted therapies include zoledronic acid, a potent biphosfonate, and denosumab, an anti-RANKL monoclonal antibody. Both reduce the risk and/or delay the development of SREs in several types of tumours. Radium 233, an alpha-particle emitter, increases overall survival in patients with bone metastases from resistant castration prostate cancer. Multidisciplinary approach is essential and bone surgery and radiotherapy should be integrated in the treatment of bone metastases when necessary. This SEOM Guideline reviews bone metastases pathogenesis, clinical presentations, lab tests, imaging techniques for diagnosis and response assessment, bone-targeted agents, and local therapies, as radiation and surgery, and establishes recommendations for the management of patients with metastases to bone.

A prospective randomized controlled clinical trial of zoledronic acid for bone metastases

In this study, we assessed the safety, tolerability, and effectiveness of two therapeutic regimens relating to the frequency of zoledronic acid (ZOL) infusion. Sixty adult patients with bone metastases were randomly assigned to two study groups. The first group (group A) received 4 mg ZOL every two weeks, and the second group (group B) received 4 mg ZOL every four weeks. Assessment measures included C-telopeptide (CTX) rate, the Greek Brief Pain Inventory (GBPI), the linear analogue scale assessment (LASA) of quality of life, and biochemical markers. Assessments were made at weeks 12, 24, 36, and 48. Clinical endpoints included effective decrease in bone resorption markers, pain relief, and improvement of mobility status. The follow-up period was 48 weeks. No statistically significant differences between groups A and B were found in overall profile of biochemical markers, Eastern Cooperative Oncology Group (ECOG) performance status, and GBPI score at the end of the follow-up period. Assessment of bone metastases revealed a slight difference between the two groups, however this difference was not statistically significant. These findings indicate that administering zoledronic acid at four rather that two weeks has no significant impact on overall outcome.

Health resource utilization associated with skeletal-related events: results from a retrospective European study

BACKGROUND

Bone complications, also known as skeletal-related events (SREs), are common in patients with bone metastases secondary to advanced cancers.

OBJECTIVE

To provide a detailed estimate of the health resource utilization (HRU) burden associated with SREs across eight European countries.

METHODS

Eligible patients from centers in Austria, the Czech Republic, Finland, Greece, Poland, Portugal, Sweden, and Switzerland with bone metastases or lesions secondary to breast cancer, prostate, or lung cancer or multiple myeloma who had experienced at least one SRE (defined as radiation to bone, long-bone pathologic fracture, other bone pathologic fracture, surgery to bone or spinal cord compression) were entered into this study. HRU data were extracted retrospectively from the patients' charts from 3.5 months before the index SRE until 3 months after the index SRE (defined as an SRE preceded by an SRE-free period of at least 6.5 months).

RESULTS

Overall, the mean number of inpatient stays per SRE increased from baseline by approximately 0.5-1.5 stays, with increases in the total duration of inpatient stays of approximately 6-37 days per event. All SREs were associated with substantial increases from baseline in the frequency of procedures and the number of outpatient and day-care visits.

CONCLUSIONS

SREs are associated with substantial HRU owing to considerable increases in the number and duration of inpatient stays, and in the number of procedures, outpatient visits, and day-care visits. These data collectively provide a valuable summary of the real-world SRE burden on European healthcare systems.

Renal safety of 1-hour pamidronate infusion for breast cancer and multiple myeloma patients: comparison between clinical trials and population-based database

Purpose. The American Society of Clinical Oncology recommends infusion of pamidronate over 2 hours to avoid renal deterioration, although there are data to suggest that 1-hour infusions may be safe.

Methods, Prevalence of renal deterioration with 1-hour pamidronate infusions from a population database was compared to renal deterioration with 2-hour pamidronate infusions, in randomised, controlled, trials. A cost-minimisation analysis, comparing the 1-and 2-hour pamidronate infusions, and the 15-minute infusion of zoledronic acid, was performed with a sensitivity analysis that varied the opportunity cost of time in the treatment room.

Results. Renal deterioration occurred in 7.7% of 169 patients with multiple myeloma and metastatic breast cancer. There is no evidence that this differs from the 10% reported in randomised, controlled, trials (one-tailed binomial test, P=0.3874). A subgroup analysis showed that renal deterioration occurred in 15 and 1.1% of patients with multiple myeloma and metastatic breast cancer, respectively. The median increase in serum creatinine was 13 and 7% in the multiple myeloma and breast cancer groups, respectively. The respective costs/dose (drug/ labour/supplies) of pamidronate and zoledronic acid are $325 and $610. Cost neutrality occurs if the opportunity cost of chair time is $6.33/ minute for pamidronate 1-hour versus zoledronic acid, and $2.71/minute for pamidronate 2-hour versus zoledronic acid. If a median $4/minute is used, the respective costs of pamidronate 1-hour, 2-hour, and zoledronic acid infusions are $685, $925, and $790/cycle.

Conclusions. Prevalence of renal deterioration with 1-hour pamidronate infusions from a population database was not significantly different to 2-hour pamidronate infusions in clinical trials. Our findings suggest further support for the safety of 1-hour pamidronate infusions. Pamidronate via 1-hour infusion is less expensive than zoledronic acid.

Synergistic Antiproliferative Effects of Zoledronic Acid and Fluvastatin on Human Pancreatic Cancer Cell Lines: An in Vitro Study

Bisphosphonates and statins are known to have antitumor activities against different types of cancer cell lines. In the present study, we investigated the antiproliferative effects of the combination of zoledronic acid (ZOL), a bisphophosphonate, and fluvastatin (FLU), a statin, in vitro on two types of human pancreatic cancer cell lines, Mia PaCa-2 and Suit-2. The pancreatic cancer cell lines were treated with ZOL and FLU both individually and in combination to evaluate their antiproliferative effects using WST-8 cell proliferation assay. In this study, we demonstrated a potent synergistic antiproliferative effect of both drugs when used in combination in both cell lines. Moreover, we studied the molecular mechanism behind this synergistic effect, which was inhibited by the addition of the mevalonate pathway products, farnesyl pyrophosphate (FPP) and geranylgeranyl pyrophosphate (GGPP). Furthermore, we aimed to determine the effect of ZOL and FLU combination on RhoA and Ras guanosine 5'-triphosphate (GTP)-proteins. The combination induced a marked accumulation in RhoA and unprenylated Ras. GGPP and FPP reversed the increase in the amount of both proteins. These results indicated that the combination treatment impaired RhoA and Ras signaling pathway by the inhibition of geranylgeranylation and/or farnesylation. This study provides a potentially effective approach for the treatment of pancreatic cancer using a combination treatment of ZOL and FLU.

Pharmacologic management of bone-related complications and bone metastases in postmenopausal women with hormone receptor-positive breast cancer

There is a high risk for bone loss and skeletal-related events, including bone metastases, in postmenopausal women with hormone receptor-positive breast cancer. Both the disease itself and its therapeutic treatments can negatively impact bone, resulting in decreases in bone mineral density and increases in bone loss. These negative effects on the bone can significantly impact morbidity and mortality. Effective management and minimization of bone-related complications in postmenopausal women with hormone receptor-positive breast cancer remain essential. This review discusses the current understanding of molecular and biological mechanisms involved in bone turnover and metastases, increased risk for bone-related complications from breast cancer and breast cancer therapy, and current and emerging treatment strategies for managing bone metastases and bone turnover in postmenopausal women with hormone receptor-positive breast cancer.

Diagnosis and treatment of bone metastasis: comprehensive guideline of the Japanese Society of Medical Oncology, Japanese Orthopedic Association, Japanese Urological Association, and Japanese Society for Radiation Oncology

Diagnosis and treatment of bone metastasis requires various types of measures, specialists and caregivers. To provide better diagnosis and treatment, a multidisciplinary team approach is required. The members of this multidisciplinary team include doctors of primary cancers, radiologists, pathologists, orthopaedists, radiotherapists, clinical oncologists, palliative caregivers, rehabilitation doctors, dentists, nurses, pharmacists, physical therapists, occupational therapists, medical social workers, etc. Medical evidence was extracted from published articles describing meta-analyses or randomised controlled trials concerning patients with bone metastases mainly from 2003 to 2013, and a guideline was developed according to the Medical Information Network Distribution Service Handbook for Clinical Practice Guideline Development 2014. Multidisciplinary team meetings are helpful in diagnosis and treatment. Clinical benefits such as physical or psychological palliation obtained using the multidisciplinary team approaches are apparent. We established a guideline describing each specialty field, to improve understanding of the different fields among the specialists, who can further provide appropriate treatment, and to improve patients’ outcomes.

The miR-21/PTEN/Akt signaling pathway is involved in the anti-tumoral effects of zoledronic acid in human breast cancer cell lines

Preclinical data indicate a direct anti-tumor effect of zoledronic acid (ZA) outside the skeleton, but its molecular mechanism is still not completely clarified. The aim of this study was to investigate the anti-cancer effects of ZA in human breast cancer cell lines, suggesting that they may in part be mediated via the miR-21/PTEN/Akt signaling pathway. The effect of ZA on cell viability was measured by MTT assay, and cell death induction was analyzed using either a double AO/EtBr staining and M30 ELISA assay. A Proteome Profiler Human Apoptosis Array was executed to evaluate the molecular basis of ZA-induced apoptosis. Cell cycle analysis was executed by flow cytometry. The effect of ZA on miR-21 expression was quantified by qRT-PCR, and the amount of PTEN protein and its targets were analyzed by Western blot. ZA inhibited cell growth in a concentration- and time-dependent manner, through the activation of cell death pathways and arrest of cell cycle progression. ZA downregulated the expression of miR-21, resulting in dephosphorilation of Akt and Bad and in a significant increase of p21 and p27 proteins expression. These results were observed also in MDA-MB-231 cells, commonly used as an experimental model of bone metastasis of breast cancer. This study revealed, for the first time, an involvement of the miR-21/PTEN/Akt signaling pathway in the mechanism of ZA anti-cancer actions in breast cancer cells. We would like to underline that this pathway is present both in the hormone responsive BC cell line (MCF-7) as well as in a triple negative cell line (MDA-MB-231). Taken together these results reinforce the use of ZA in clinical practice, suggesting the role of miR-21 as a possible mediator of its therapeutic efficacy.

A randomized, double-blind, phase II, exploratory trial evaluating the palliative benefit of either continuing pamidronate or switching to zoledronic acid in patients with high-risk bone metastases from breast cancer

Previous studies suggest switching from pamidronate to a more potent bone-targeted agent is associated with biomarker and palliative response in breast cancer patients with bone metastases. Until now, this has not been addressed in a double-blind, randomized trial. Breast cancer patients with high-risk bone metastases, despite >3 months of pamidronate, were randomized to either continue pamidronate or switch to zoledronic acid every 4 weeks for 12 weeks. Primary outcome was the proportion of patients achieving a fall in serum C-telopeptide (sCTx) at 12 weeks. Secondary outcomes included difference in mean sCTx, pain scores, quality of life, toxicity, and skeletal-related events (SREs). Seventy-three patients entered the study; median age 61 years (range 37-87). Proportion of patients achieving a fall in sCTx over the 12-week evaluation period was 26/32 (81 %) with zoledronic acid and 18/29 (62 %) with pamidronate (p = 0.095). Mean decrease in sCTx (mean difference between groups = 50 ng/L, 95 % CI 18-84; p = 0.003) was significantly greater in patients who received zoledronic acid. Quality of life, pain scores, toxicity, and frequency of new SREs were comparable between the two arms. While a switch from pamidronate to zoledronic acid resulted in reduction in mean sCTx, there were no significant differences between the arms for proportion of patients achieving a reduction in sCTx, quality of life, pain scores, toxicity or SREs. Given the lack of palliative improvement, the current data do not support a switching strategy.