Oral clodronate for adjuvant treatment of operable breast cancer (National Surgical Adjuvant Breast and Bowel Project protocol B-34): a multicentre, placebo-controlled, randomised trial

Bone-Induced HER2 Promotes Secondary Metastasis in HR+/HER2- Breast Cancer

SIGNIFICANCE

Given the urgent need for alternative strategies to block metastasis progression, we demonstrate that blocking HER2-mediated secondary metastasis improves clinical outcome and establish HER2 as a biomarker for bone metastasis in patients with initial HR+/HER2- breast cancer, which represents ∼70% of all cases.

Augmenting Insufficiently Accruing Oncology Clinical Trials Using Generative Models: Validation Study

BACKGROUND

Insufficient patient accrual is a major challenge in clinical trials and can result in underpowered studies, as well as exposing study participants to toxicity and additional costs, with limited scientific benefit. Real-world data can provide external controls, but insufficient accrual affects all arms of a study, not just controls. Studies that used generative models to simulate more patients were limited in the accrual scenarios considered, replicability criteria, number of generative models, and number of clinical trials evaluated.

OBJECTIVE

This study aimed to perform a comprehensive evaluation on the extent generative models can be used to simulate additional patients to compensate for insufficient accrual in clinical trials.

METHODS

We performed a retrospective analysis using 10 datasets from 9 fully accrued, completed, and published cancer trials. For each trial, we removed the latest recruited patients (from 10% to 50%), trained a generative model on the remaining patients, and simulated additional patients to replace the removed ones using the generative model to augment the available data. We then replicated the published analysis on this augmented dataset to determine if the findings remained the same. Four different generative models were evaluated: sequential synthesis with decision trees, Bayesian network, generative adversarial network, and a variational autoencoder. These generative models were compared to sampling with replacement (ie, bootstrap) as a simple alternative. Replication of the published analyses used 4 metrics: decision agreement, estimate agreement, standardized difference, and CI overlap.

RESULTS

Sequential synthesis performed well on the 4 replication metrics for the removal of up to 40% of the last recruited patients (decision agreement: 88% to 100% across datasets, estimate agreement: 100%, cannot reject standardized difference null hypothesis: 100%, and CI overlap: 0.8-0.92). Sampling with replacement was the next most effective approach, with decision agreement varying from 78% to 89% across all datasets. There was no evidence of a monotonic relationship in the estimated effect size with recruitment order across these studies. This suggests that patients recruited earlier in a trial were not systematically different than those recruited later, at least partially explaining why generative models trained on early data can effectively simulate patients recruited later in a trial. The fidelity of the generated data relative to the training data on the Hellinger distance was high in all cases.

CONCLUSIONS

For an oncology study with insufficient accrual with as few as 60% of target recruitment, sequential synthesis can enable the simulation of the full dataset had the study continued accruing patients and can be an alternative to drawing conclusions from an underpowered study. These results provide evidence demonstrating the potential for generative models to rescue poorly accruing clinical trials, but additional studies are needed to confirm these findings and to generalize them for other diseases.

Macrophages: Key Players in the Battle against Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) is a challenging subtype of breast cancer characterized by the absence of estrogen and progesterone receptors and HER2 expression, leading to limited treatment options and a poorer prognosis. TNBC is particularly prevalent in premenopausal African-descent women and is associated with aggressive tumor behavior and higher metastatic potential. Tumor-associated macrophages (TAMs) are abundantly present within the TNBC microenvironment and play pivotal roles in promoting tumor growth, progression, and metastasis through various mechanisms, including immune suppression and enhancement of angiogenesis. This review provides an in-depth overview of TNBC, focusing on its epidemiology, its molecular characteristics, and the critical influence of TAMs. It discusses the pathological and molecular aspects that define TNBC's aggressive nature and reviews current and emerging therapeutic strategies aimed at targeting these dynamics. Special attention is given to the role of TAMs, exploring their potential as therapeutic targets due to their significant impact on tumor behavior and patient outcomes. This review aims to highlight the complexities of the TNBC landscape and to present the innovative approaches that are currently being pursued to improve therapeutic efficacy and patient survival.

Bridging the gap - Establishing a dental-oncology service in a cancer centre

Dental disease remains the most common non-communicable disease worldwide. It predisposes patients to significant morbidities following bone modifying agents or radiation therapy to the head and neck. Preventative dental regimes effectively reduce the risk of both medication-related osteonecrosis of the jaw (MRONJ) and osteoradionecrosis (ORN) in these patients. Co-ordination of routine dental care as a component of mainstream oncology treatment optimises long term outcomes for oncology patients. This case series offers insights into patient, institutional and social difficulties that challenge the dental-oncology interface. These obstacles and subsequent resolutions experienced whilst establishing a dental-oncology service in a cancer centre highlight the importance of effective multidisciplinary lead care for oncology patients. It reinforces the need for structured, supported dental pathways for these oncology patients.

Approach to Bone Health in the Patient With Breast Cancer

Treatment for breast cancer, including endocrine therapies, can contribute to bone loss and increase the risk of osteoporosis and fractures. Management of bone health in patients with cancer is often coordinated between oncologists, endocrinologists, and primary care physicians. In this article, we discuss the approach to screening for fracture risk among patients initiating treatments for breast cancer and recommendations for lifestyle modifications to optimize bone health. We will review 3 indications for pharmacologic bone-targeted therapies: prevention of cancer treatment-induced bone loss, adjuvant therapy to reduce recurrence, and management of bone metastases.

How we manage medication-related osteonecrosis of the jaw

Bone-modifying agents (BMAs) are integral to managing patients with advanced cancer. They improve quality of survival by reducing skeletal-related events, treating hypercalcaemia and chemotherapy-induced bone loss (Coleman in Clin Cancer Res 12: 6243s-6249s, 2006), (Coleman in Ann Oncol 31: 1650-1663, 2020). Two decades ago, medication-related osteonecrosis of the jaw (MRONJ) was first reported following BMA therapy (Marx in J Oral Maxillofac Surg 61: 1115-1117, 2003). The risk of MRONJ extends over a decade following BMA treatment with bisphosphonates, complicating dental care such as extractions. In addition, MRONJ has been reported following additional therapies such as antiangiogenic agents, cytotoxic agents, immunotherapy, and targeted agents. The use of BMAs in the curative and adjuvant cancer setting is increasing, consequently the implication of MRONJ is growing. Over the past 20 years, the literature has consolidated major risk factors for MRONJ, the pathophysiology and management strategies for MRONJ. Our review aims to document the development of MRONJ preventative and management strategies in cancer patients receiving a BMA. The authors advocate the incorporation of dental oncology strategies into contemporary cancer care, to optimise long-term quality of survival after cancer treatment.

The emerging role of osteoclasts in the treatment of bone metastases: rationale and recent clinical evidence

The occurrence of bone metastasis is a grave medical concern that substantially impacts the quality of life in patients with cancer. The precise mechanisms underlying bone metastasis remain unclear despite extensive research efforts, and efficacious therapeutic interventions are currently lacking. The ability of osteoclasts to degrade the bone matrix makes them a crucial factor in the development of bone metastasis. Osteoclasts are implicated in several aspects of bone metastasis, encompassing the formation of premetastatic microenvironment, suppression of the immune system, and reactivation of quiescent tumor cells. Contemporary clinical interventions targeting osteoclasts have proven effective in mitigating bone-related symptoms in patients with cancer. This review comprehensively analyzes the mechanistic involvement of osteoclasts in bone metastasis, delineates potential therapeutic targets associated with osteoclasts, and explores clinical evidence regarding interventions targeting osteoclasts.

Bone-modifying agents for reducing bone loss in women with early and locally advanced breast cancer: a network meta-analysis

BACKGROUND

Bisphosphonates and receptor activator of nuclear factor-kappa B ligand (RANKL)-inhibitors are amongst the bone-modifying agents used as supportive treatment in women with breast cancer who do not have bone metastases. These agents aim to reduce bone loss and the risk of fractures. Bisphosphonates have demonstrated survival benefits, particularly in postmenopausal women.

OBJECTIVES

To assess and compare the effects of different bone-modifying agents as supportive treatment to reduce bone mineral density loss and osteoporotic fractures in women with breast cancer without bone metastases and generate a ranking of treatment options using network meta-analyses (NMAs).

SEARCH METHODS

We identified studies by electronically searching CENTRAL, MEDLINE and Embase until January 2023. We searched various trial registries and screened abstracts of conference proceedings and reference lists of identified trials.

SELECTION CRITERIA

We included randomised controlled trials comparing different bisphosphonates and RANKL-inihibitors with each other or against no further treatment or placebo for women with breast cancer without bone metastases.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed the risk of bias of included studies and certainty of evidence using GRADE. Outcomes were bone mineral density, quality of life, overall fractures, overall survival and adverse events. We conducted NMAs and generated treatment rankings.

MAIN RESULTS

Forty-seven trials (35,163 participants) fulfilled our inclusion criteria; 34 trials (33,793 participants) could be considered in the NMA (8 different treatment options). Bone mineral density We estimated that the bone mineral density of participants with no treatment/placebo measured as total T-score was -1.34. Evidence from the NMA (9 trials; 1166 participants) suggests that treatment with ibandronate (T-score -0.77; MD 0.57, 95% CI -0.05 to 1.19) may slightly increase bone mineral density (low certainty) and treatment with zoledronic acid (T-score -0.45; MD 0.89, 95% CI 0.62 to 1.16) probably slightly increases bone mineral density compared to no treatment/placebo (moderate certainty). Risedronate (T-score -1.08; MD 0.26, 95% CI -0.32 to 0.84) may result in little to no difference compared to no treatment/placebo (low certainty). We are uncertain whether alendronate (T-score 2.36; MD 3.70, 95% CI -2.01 to 9.41) increases bone mineral density compared to no treatment/placebo (very low certainty). Quality of life No quantitative analyses could be performed for quality of life, as only three studies reported this outcome. All three studies showed only minimal differences between the respective interventions examined. Overall fracture rate We estimated that 70 of 1000 participants with no treatment/placebo had fractures. Evidence from the NMA (16 trials; 19,492 participants) indicates that treatment with clodronate or ibandronate (42 of 1000; RR 0.60, 95% CI 0.39 to 0.92; 40 of 1000; RR 0.57, 95% CI 0.38 to 0.86, respectively) decreases the number of fractures compared to no treatment/placebo (high certainty). Denosumab or zoledronic acid (51 of 1000; RR 0.73, 95% CI 0.52 to 1.01; 55 of 1000; RR 0.79, 95% CI 0.56 to 1.11, respectively) probably slightly decreases the number of fractures; and risedronate (39 of 1000; RR 0.56, 95% CI 0.15 to 2.16) probably decreases the number of fractures compared to no treatment/placebo (moderate certainty). Pamidronate (106 of 1000; RR 1.52, 95% CI 0.75 to 3.06) probably increases the number of fractures compared to no treatment/placebo (moderate certainty). Overall survival We estimated that 920 of 1000 participants with no treatment/placebo survived overall. Evidence from the NMA (17 trials; 30,991 participants) suggests that clodronate (924 of 1000; HR 0.95, 95% CI 0.77 to 1.17), denosumab (927 of 1000; HR 0.91, 95% CI 0.69 to 1.21), ibandronate (915 of 1000; HR 1.06, 95% CI 0.83 to 1.34) and zoledronic acid (925 of 1000; HR 0.93, 95% CI 0.76 to 1.14) may result in little to no difference regarding overall survival compared to no treatment/placebo (low certainty). Additionally, we are uncertain whether pamidronate (905 of 1000; HR 1.20, 95% CI 0.81 to 1.78) decreases overall survival compared to no treatment/placebo (very low certainty). Osteonecrosis of the jaw We estimated that 1 of 1000 participants with no treatment/placebo developed osteonecrosis of the jaw. Evidence from the NMA (12 trials; 23,527 participants) suggests that denosumab (25 of 1000; RR 24.70, 95% CI 9.56 to 63.83), ibandronate (6 of 1000; RR 5.77, 95% CI 2.04 to 16.35) and zoledronic acid (9 of 1000; RR 9.41, 95% CI 3.54 to 24.99) probably increases the occurrence of osteonecrosis of the jaw compared to no treatment/placebo (moderate certainty). Additionally, clodronate (3 of 1000; RR 2.65, 95% CI 0.83 to 8.50) may increase the occurrence of osteonecrosis of the jaw compared to no treatment/placebo (low certainty). Renal impairment We estimated that 14 of 1000 participants with no treatment/placebo developed renal impairment. Evidence from the NMA (12 trials; 22,469 participants) suggests that ibandronate (28 of 1000; RR 1.98, 95% CI 1.01 to 3.88) probably increases the occurrence of renal impairment compared to no treatment/placebo (moderate certainty). Zoledronic acid (21 of 1000; RR 1.49, 95% CI 0.87 to 2.58) probably increases the occurrence of renal impairment while clodronate (12 of 1000; RR 0.88, 95% CI 0.55 to 1.39) and denosumab (11 of 1000; RR 0.80, 95% CI 0.54 to 1.19) probably results in little to no difference regarding the occurrence of renal impairment compared to no treatment/placebo (moderate certainty).

AUTHORS' CONCLUSIONS

When considering bone-modifying agents for managing bone loss in women with early or locally advanced breast cancer, one has to balance between efficacy and safety. Our findings suggest that bisphosphonates (excluding alendronate and pamidronate) or denosumab compared to no treatment or placebo likely results in increased bone mineral density and reduced fracture rates. Our survival analysis that included pre and postmenopausal women showed little to no difference regarding overall survival. These treatments may lead to more adverse events. Therefore, forming an overall judgement of the best ranked bone-modifying agent is challenging. More head-to-head comparisons, especially comparing denosumab with any bisphosphonate, are needed to address gaps and validate the findings of this review.

Benefit of adjuvant bisphosphonates in early breast cancer treated with contemporary systemic therapy: A meta-analysis of randomized control trials

Background

The absolute and relative benefits of adjuvant bisphosphonates on disease-free survival and overall survival in patients receiving contemporary systemic therapy for early breast cancer is uncertain.

Methods

Data from randomized trials of adjuvant bisphosphonates that recruited patients exclusively after 2000 and reported disease free survival and overall survival was utilized. Five-year disease-free survival and overall survival in bisphosphonates and control group along with associated hazard ratios were extracted. Absolute data were weighted by sample size and hazard ratios were pooled using inverse variance and random effects modelling. Meta-regression comprising linear regression weighted by sample size (mixed effects) was performed to explore association between disease and treatment related factors and absolute differences in benefit from bisphosphonates.

Results

Eleven trials comprising 24023 patients were included in the analysis. For disease free survival, pooled hazard ratio was 0.89 (0.81-0.97, p = 0.008) with a 1.5 % weighted mean difference favoring bisphosphonates over control. There was no significant overall survival benefit (0.92, 0.82-1.03, p = 0.16). Among patients receiving anthracycline and taxane based chemotherapy, there were no differences in either disease free survival (0.95, 0.80-1.12) or overall survival (1.04, 0.81-1.32). Meta-regression showed lower benefits in higher risk patients (node-positive, larger tumor size, estrogen receptor-, grade 3 or those receiving chemotherapy). Overall, 1 % (95 % CI 0.75-1.15) of patients experienced osteonecrosis of jaw related to zoledronic acid.

Conclusions

Compared to the Early Breast Cancer Trialist's Collaborative Group meta-analysis, benefit from adjuvant bisphosphonates is lower in recent trials especially in higher risk patients receiving contemporary chemotherapy. The balance between benefits and risks of adjuvant bisphosphonates should be considered in individual patients.

Evaluating the Utility and Privacy of Synthetic Breast Cancer Clinical Trial Data Sets

PURPOSE

There is strong interest from patients, researchers, the pharmaceutical industry, medical journal editors, funders of research, and regulators in sharing clinical trial data for secondary analysis. However, data access remains a challenge because of concerns about patient privacy. It has been argued that synthetic data generation (SDG) is an effective way to address these privacy concerns. There is a dearth of evidence supporting this on oncology clinical trial data sets, and on the utility of privacy-preserving synthetic data. The objective of the proposed study is to validate the utility and privacy risks of synthetic clinical trial data sets across multiple SDG techniques.

METHODS

We synthesized data sets from eight breast cancer clinical trial data sets using three types of generative models: sequential synthesis, conditional generative adversarial network, and variational autoencoder. Synthetic data utility was evaluated by replicating the published analyses on the synthetic data and assessing concordance of effect estimates and CIs between real and synthetic data. Privacy was evaluated by measuring attribution disclosure risk and membership disclosure risk.

RESULTS

Utility was highest using the sequential synthesis method where all results were replicable and the CI overlap most similar or higher for seven of eight data sets. Both types of privacy risks were low across all three types of generative models.

DISCUSSION

Synthetic data using sequential synthesis methods can act as a proxy for real clinical trial data sets, and simultaneously have low privacy risks. This type of generative model can be one way to enable broader sharing of clinical trial data.

Macrophages as Promising Carriers for Nanoparticle Delivery in Anticancer Therapy

Macrophages play a critical role in the immune response due to their ability to recognize and remove pathogens, as well as present antigens, which are involved in inflammation, but they are also one of the most abundant immune cell populations present in the tumor microenvironment. In recent years, macrophages have become promising cellular carriers for drug and nanoparticle delivery to the tumor microenvironment, mainly due to their natural properties such as biocompatibility, degradability, lack of immunogenicity, long half-life in circulation, crossing biological barriers, and the possibility of migration and accumulation at a site of inflammation such as a tumor. For the effectiveness of this therapeutic strategy, known as "Trojan horse", it is important that the nanoparticles engulfed by macrophages do not affect their proper functioning. In our review, we discussed how the size, shape, chemical and mechanical properties of nanoparticles influence their internalization by macrophages. In addition, we described the promising research utilizing macrophages, their cell membranes and macrophage-derived exosomes as drug carriers in anticancer therapy. As a prospect of the wider use of this therapeutic strategy, we postulate its future application in boron delivery to the tumor environment in boron neutron capture therapy.

Metastasis prevention with bone-targeted agents: a complex interaction between the microenvironment and tumour biology

INTRODUCTION

The use of bone-targeted treatments has transformed the clinical care of many patients with metastatic breast cancer. In addition, due to the profound effects of bisphosphonates and denosumab on bone physiology and the bone microenvironment, the potential of bone-targeted agents to modify the process of metastasis has been studied extensively.

FINDINGS

Many adjuvant trials with bisphosphonates in early breast cancer have been performed. Variable outcomes in terms of disease recurrence have been reported, with any treatment benefits apparently influenced by the age and menopausal status of the patients. Results show that in breast cancer the use of adjuvant bisphosphonates reduce bone metastases and breast-cancer deaths in postmenopausal women. These effects are in addition to the benefits associated with the use of standard adjuvant endocrine, cytotoxic and targeted treatments with prevention of one in six breast-cancer deaths at 10 years. Biomarkers that can predict patient benefit from the use of bone-targeted treatments in the adjuvant setting are being evaluated. Currently, tumour expression of the transcription factor, MAF, seems to be the most promising biomarker; benefits from adjuvant bisphosphonates are seen in the 80% of patients with normal levels of expression irrespective of menopausal status and age, while over expression is associated with a poor prognosis and a higher rate of visceral metastases.

CONCLUSIONS

Adjuvant bisphosphonates are now part of standard clinical guidelines for postmenopausal women with early breast cancer at intermediate to high risk of recurrence. MAF testing of primary tumours may improve patient selection for treatment.

Advances in the Management of Menopausal Symptoms, Fertility Preservation, and Bone Health for Women With Breast Cancer on Endocrine Therapy

In patients with hormone receptor-positive early-stage breast cancer, adjuvant endocrine treatment administered for up to 5-10 years after diagnosis significantly reduces the risk of recurrence and death. However, this benefit comes with the cost of short- and long-term side effects that may negatively affect patients' quality of life (QoL) and treatment adherence. Among them, the prolonged estrogen suppression associated with the use of adjuvant endocrine therapy in both premenopausal and postmenopausal women can induce life-altering menopausal symptoms, including sexual dysfunction. Moreover, a decrease in bone mineral density and an increased risk of fractures should be carefully considered and prevented whenever indicated. For young women diagnosed with hormone receptor-positive breast cancer with unfulfilled childbearing plans, several challenges should be addressed to manage their fertility and pregnancy-related concerns. Proper counseling and proactive management of these issues are critical components of survivorship and should be pursued from diagnosis through the breast cancer care continuum. This study aims to provide an updated overview of the available approaches for improving the QoL of patients with breast cancer receiving estrogen deprivation therapy, focusing on advances in the management of menopausal symptoms, including sexual dysfunction, fertility preservation, and bone health.

Brief review: Applications of nanocomposite in electrochemical sensor and drugs delivery

The recent advancement of nanoparticles (NPs) holds significant potential for treating various ailments. NPs are employed as drug carriers for diseases like cancer because of their small size and increased stability. In addition, they have several desirable properties that make them ideal for treating bone cancer, including high stability, specificity, higher sensitivity, and efficacy. Furthermore, they might be taken into account to permit the precise drug release from the matrix. Drug delivery systems for cancer treatment have progressed to include nanocomposites, metallic NPs, dendrimers, and liposomes. Materials’ mechanical strength, hardness, electrical and thermal conductivity, and electrochemical sensors are significantly improved using nanoparticles (NPs). New sensing devices, drug delivery systems, electrochemical sensors, and biosensors can all benefit considerably from the NPs’ exceptional physical and chemical capabilities. Nanotechnology is discussed in this article from a variety of angles, including its recent applications in the medical sciences for the effective treatment of bone cancers and its potential as a promising option for treating other complex health anomalies via the use of anti-tumour therapy, radiotherapy, the delivery of proteins, antibiotics, and vaccines, and other methods. This also brings to light the role that model simulations can play in diagnosing and treating bone cancer, an area where Nanomedicine has recently been formulated. There has been a recent uptick in using nanotechnology to treat conditions affecting the skeleton. Consequently, it will pave the door for more effective utilization of cutting-edge technology, including electrochemical sensors and biosensors, and improved therapeutic outcomes.

Bisphosphonates and Prevention of the Perimenopausal Breast Cancer Recurrence: A Systematic Review and Meta-Analysis

PURPOSE

Bisphosphonates (BPs) have a powerful effect on reducing bone resorption and improving the survival of patients with breast cancer. We aimed to investigate the impact of BP treatment on the prevention of recurrence, metastasis, and death of breast cancer survivors in the perimenopausal period.

METHODS

The search strategy aimed to identify both published and unpublished studies in PubMed, Web of Science, Scopus, Embase, ProQuest, and Google Scholar in March 2021. Two independent reviewers assessed quantitative papers selected for retrieval for methodological validity before being included in the review using standardized critical appraisal instruments from the Joanna Briggs Institute (JBI) Meta-Analysis of Statistics Assessment and Review Instrument (JBI-MAStARI). Statistical meta-analysis was performed using Review Manager (RevMan) 5.4 statistical software when the data were homogenous. Meta-analysis was performed by calculating the effect size (hazard ratio; HR) and 95% confidence intervals (CIs).

RESULTS

Twenty-one studies were eligible for this systematic review and meta-analysis. The overall The HRs for disease-free survival (DFS) and overall survival (OS) in women who received BPs were 0.89 (95% CI, 0.83-0.97; p = 0.005), and 0.75 (95% CI, 0.63-0.89; p = 0.001), respectively. The results showed that BPs had a significant effect on the prevention of locoregional (HR, 0.64; 95% CI, 0.42-0.97; p = 0.04), bone (95% CI, 0.74-0.95; p ≤ 0.001), and distant metastases (HR, 0.77; 95% CI, 0.62-0.94; p = 0.01). In the subgroup analysis based on study design, the only insignificant HR in the included randomized controlled trials (RCTs) was that of locoregional metastasis.

CONCLUSION

Although BPs have a promising effect on DFS, OS, and bone metastasis of perimenopausal women survivors of breast cancer, more RCTs are needed to evaluate their effect on other survivors' outcomes.

Daily Oral Ibandronate With Adjuvant Endocrine Therapy in Postmenopausal Women With Estrogen Receptor-Positive Breast Cancer (BOOG 2006-04): Randomized Phase III TEAM-IIB Trial

PURPOSE

For postmenopausal patients with breast cancer, previous subgroup analyses have shown a modest benefit from adjuvant bisphosphonate treatment. However, the efficacy of oral nitrogen-containing bisphosphonates such as ibandronate is unclear in this setting. TEAM-IIB investigates adjuvant ibandronate in postmenopausal women with estrogen receptor-positive (ER+) breast cancer.

METHODS

TEAM-IIB is a randomized, open-label, multicenter phase III study. Postmenopausal women with stage I-III ER+ breast cancer and an indication for adjuvant endocrine therapy (ET) were randomly assigned 1:1 to 5 years of ET with or without oral ibandronate 50 mg once daily for 3 years. Major ineligibility criteria were bilateral breast cancer, active gastroesophageal problems, and health conditions that might interfere with study treatment. Primary end point was disease-free survival (DFS), analyzed in the intention-to-treat population.

RESULTS

Between February 1, 2007, and May 27, 2014, 1,116 patients were enrolled, 565 to ET with ibandronate (ibandronate arm) and 551 to ET alone (control arm). Median follow-up was 8.5 years. DFS was not significantly different between the ibandronate and control arms (HR, 0.97; 95% CI, 0.76 to 1.24; log-rank P = .811). Three years after random assignment, DFS was 94% in the ibandronate arm and 91% in the control arm. Five years after random assignment, this was 89% and 86%, respectively. In the ibandronate arm, 97/565 (17%) of patients stopped ibandronate early because of adverse events. Significantly more patients experienced GI issues, mainly dyspepsia, in the ibandronate arm than in the control arm (89 [16%] and 54 [10%], respectively; P < .003). Eleven patients in the ibandronate arm developed osteonecrosis of the jaw.

CONCLUSION

In postmenopausal women with ER+ breast cancer, adjuvant ibandronate 50 mg once daily does not improve DFS and should not be recommended as part of standard treatment regimens.

Bone-Targeted Agents and Metastasis Prevention

The use of bone-targeted treatments has transformed the clinical care of many patients with metastatic breast cancer. In addition, due to the profound effects of bisphosphonates and denosumab on bone physiology and the bone microenvironment, the potential of bone-targeted agents to modify the process of metastasis has been studied extensively. Many adjuvant trials with bisphosphonates in early breast cancer have been performed. Variable outcomes in terms of disease recurrence have been reported, with any treatment benefits apparently influenced by the age and menopausal status of the patients. The Early Breast Cancer Trialists' Collaborative Group (EBCTCG) conducted a meta-analysis of individual patient data from all available randomised trials to investigate this observation further. This meta-analysis failed to show any benefits of adjuvant bisphosphonates in premenopausal women, but highly significant improvements in bone recurrence (RR = 0.72; 95%CI 0.60-0.86, 2p = 0.0002) and breast cancer mortality (RR = 0.82; 95%CI 0.73-0.93, 2p = 0.002) were seen in the 11,767 postmenopausal women included in the meta-analysis. As a result, clinical guidelines recommend the incorporation of adjuvant bisphosphonates that inhibit osteoclast activity into routine clinical care. Denosumab, which has similar effects on bone cell physiology, appears not to consistently influence disease outcomes, perhaps suggesting that it is the "off target" effects of bisphosphonates on immune function and the biological processes involved in metastasis that are important. Predictive biomarkers beyond menopause are being sought and assessment of the transcription factor MAF (mesenchymal aponeurotic fibrosarcoma gene) appears to identify patients able to benefit from the addition of a bisphosphonate to standard adjuvant anticancer therapies.

Predicting Bone Metastasis Using Gene Expression-Based Machine Learning Models

Bone is the most common site of distant metastasis from malignant tumors, with the highest prevalence observed in breast and prostate cancers. Such bone metastases (BM) cause many painful skeletal-related events, such as severe bone pain, pathological fractures, spinal cord compression, and hypercalcemia, with adverse effects on life quality. Many bone-targeting agents developed based on the current understanding of BM onset's molecular mechanisms dull these adverse effects. However, only a few studies investigated potential predictors of high risk for developing BM, despite such knowledge being critical for early interventions to prevent or delay BM. This work proposes a computational network-based pipeline that incorporates a ML/DL component to predict BM development. Based on the proposed pipeline we constructed several machine learning models. The deep neural network (DNN) model exhibited the highest prediction accuracy (AUC of 92.11%) using the top 34 featured genes ranked by betweenness centrality scores. We further used an entirely separate, "external" TCGA dataset to evaluate the robustness of this DNN model and achieved sensitivity of 85%, specificity of 80%, positive predictive value of 78.10%, negative predictive value of 80%, and AUC of 85.78%. The result shows the models' way of learning allowed it to zoom in on the featured genes that provide the added benefit of the model displaying generic capabilities, that is, to predict BM for samples from different primary sites. Furthermore, existing experimental evidence provides confidence that about 50% of the 34 hub genes have BM-related functionality, which suggests that these common genetic markers provide vital insight about BM drivers. These findings may prompt the transformation of such a method into an artificial intelligence (AI) diagnostic tool and direct us towards mechanisms that underlie metastasis to bone events.

Bisphosphonates and breast cancer survival: a meta-analysis and trial sequential analysis of 81508 participants from 23 prospective epidemiological studies

BACKGROUND

We assessed the effect of bisphosphonates (BPs) on breast cancer (BCa) patient survival and explored how long the effect can persist after treatment.

METHODS

We performed a meta-analysis and trial sequential analysis (TSA) of prospective studies including randomized controlled trials (RCTs) and cohort studies. We performed extensive sensitivity analyses to assess the robustness of the findings.

RESULTS

Seventeen RCTs and eight cohorts with 81508 BCa patients were identified. A significant beneficial effect of BPs on BCa survival was found (RR, 0.725; 95% CI, 0.627-0.839), and the TSA results also suggested firm evidence for this beneficial effect. Both summarized results from RCTs and cohorts provided firm evidence for this effect, although the effect estimates were stronger from cohorts than RCTs (RR, 0.892; 95% CI, 0.829-0.961; 0.570; 95% CI, 0.436-0.745; respectively). This beneficial effect was confirmed for bone-metastases (RR, 0.713; 95% CI, 0.602-0.843) and postmenopausal women (RR, 0.737; 95% CI, 0.640-0.850). Importantly, our results demonstrated that this beneficial effect was retained at least 1-2 years after treatment completion (RR, 0.780; 95% CI, 0.638-0.954) and could persist for up to more than 4 years after treatment completion (RR, 0.906; 95% CI, 0.832-0.987). Extensive sensitivity analyses showed the robustness of our results. The GRADE quality of evidence was generally judged to be moderate to high.

CONCLUSIONS

The present study provides firm evidence for a significant beneficial effect of BPs on BCa survival in patients with early-stage BCa, and this effect was retained at least 1-2 years after BP treatment completion.

MAF Amplification and Adjuvant Clodronate Outcomes in Early-Stage Breast Cancer in NSABP B-34 and Potential Impact on Clinical Practice

Background

The Adjuvant Zoledronic Acid (ZA) study in early breast cancer (AZURE) showed correlation between a nonamplified MAF gene in the primary tumor and benefit from adjuvant ZA. Adverse ZA outcomes occurred in MAF-amplified patients. NSABP B-34 is a validation study.

Methods

A retrospective analysis of MAF gene status in NSABP B-34 was performed. Eligible patients were randomly assigned to standard adjuvant systemic treatment plus 3 years oral clodronate (1600 mg/daily) or placebo. Tumors were tested for MAF gene amplification and analyzed for their relationship to clodronate for disease-free survival (DFS) and overall survival (OS) in MAF nonamplified patients. All statistical tests were 2-sided .

Results

MAF status was assessed in 2533 available primary tumor samples from 3311 patients. Of these, 37 withdrew consent; in 77 samples, no tumor was found; 536 assays did not meet quality standards, leaving 1883 (77.8%) evaluable for MAF assay by fluorescence in situ hybridization (947 from placebo and 936 from clodronate arms). At 5 years, in MAF nonamplified patients receiving clodronate, DFS improved by 30% (hazard ratio = 0.70, 95% confidence interval = 0.51 to 0.94; P = .02). OS improved at 5 years (hazard ratio = 0.59, 95% confidence interval = 0.37 to 0.93; P = .02) remaining statistically significant for clodronate throughout study follow-up. Conversely, adjuvant clodronate in women with MAF-amplified tumors was not associated with benefit but rather possible harm in some subgroups. Association between MAF status and menopausal status was not seen.

Conclusions

Nonamplified MAF showed statistically significant benefits (DFS and OS) with oral clodronate, supporting validation of the AZURE study.

Updated Standardized Definitions for Efficacy End Points (STEEP) in Adjuvant Breast Cancer Clinical Trials: STEEP Version 2.0

PURPOSE

The Standardized Definitions for Efficacy End Points (STEEP) criteria, established in 2007, provide standardized definitions of adjuvant breast cancer clinical trial end points. Given the evolution of breast cancer clinical trials and improvements in outcomes, a panel of experts reviewed the STEEP criteria to determine whether modifications are needed.

METHODS

We conducted systematic searches of ClinicalTrials.gov for adjuvant systemic and local-regional therapy trials for breast cancer to investigate if the primary end points reported met STEEP criteria. On the basis of common STEEP deviations, we performed a series of simulations to evaluate the effect of excluding non-breast cancer deaths and new nonbreast primary cancers from the invasive disease-free survival end point.

RESULTS

Among 11 phase III breast cancer trials with primary efficacy end points, three had primary end points that followed STEEP criteria, four used STEEP definitions but not the corresponding end point names, and four used end points that were not included in the original STEEP manuscript. Simulation modeling demonstrated that inclusion of second nonbreast primary cancer can increase the probability of incorrect inferences, can decrease power to detect clinically relevant efficacy effects, and may mask differences in recurrence rates, especially when recurrence rates are low.

CONCLUSION

We recommend an additional end point, invasive breast cancer-free survival, which includes all invasive disease-free survival events except second nonbreast primary cancers. This end point should be considered for trials in which the toxicities of agents are well-known and where the risk of second primary cancer is small. Additionally, we provide end point recommendations for local therapy trials, low-risk populations, noninferiority trials, and trials incorporating patient-reported outcomes.

Bone-modifying Agents (BMAs) in Breast Cancer

Bone-modifying agents (BMAs) are mainstays in breast cancer and prevent and treat osteoporosis in early-stage disease and reduce skeletal metastases complications in advanced disease. There is some evidence to support that BMA also prevents skeletal metastases and improves overall survival. Bone loss occurs with chemotherapy-induced ovarian failure, gonadotrophin-releasing hormone (GnRH) agonists, and aromatase inhibitors. In some women, the bone loss will be of sufficient magnitude to increase the risks of osteoporosis or fractures. Recommended steps in osteoporosis prevention or treatment include risk factor assessment, taking adequate amounts of calcium and vitamin D3, and periodic evaluations with dual-energy x-ray absorptiometry scanning. If clinically indicated by the T-scores and fracture-risk prediction algorithms treat with oral, IV bisphosphonates or subcutaneous denosumab (DEN). Zoledronic acid (ZA) or DEN reduces skeletal metastases complications, including pathological fracture, spinal cord compression, or the necessity for radiation or surgery to bone. Also, both of these drugs have the side-effect of osteonecrosis at a similar incidence. Monthly administration of ZA or DEN is standard, but several recent randomized trials show noninferiority between ZA monthly and every 3-month ZA. Every 3-month ZA is a new standard of care. Similar trials of the schedule of DEN are ongoing. ZA anticancer effect is only in postmenopausal women or premenopausal women rendered postmenopausal by GnRH agonists or bilateral oopherectomy. High-risk women, either postmenopausal or premenopausal, receiving GnRH/oopherctomy should consider adjuvant ZA. There are insufficient data to support DEN in this setting. Herein, this narrative review covers the mechanism of action of BMA, randomized clinical trials, and adverse events, both common and rare.

Long-term outcome of (neo)adjuvant zoledronic acid therapy in locally advanced breast cancer

PURPOSE

The role of zoledronic acid (ZOL), a bone-targeted bisphosphonate, in the treatment of patients with breast cancer remains an active area of study. Here, we report the long-term outcomes of a randomized placebo-controlled phase II clinical trial in which ZOL treatment was added to neoadjuvant chemotherapy in women with locally advanced breast cancer.

METHODS

120 women with clinical stage II-III (≥ T2 and/or ≥ N1) newly diagnosed breast cancer were randomized to receive either 4 mg intravenous ZOL every 3 weeks for 1 year (17 total doses) beginning with the first dose of neoadjuvant chemotherapy, or chemotherapy alone. Clinical endpoints included time to recurrence (TTR), time to bone recurrence (TTBR), time to non-bone recurrence (TTNBR), breast cancer survival (BCS) and overall survival (OS).

RESULTS

With a median follow-up interval of 14.4 years, there were no significant differences in any of the clinical endpoints studied between the control and ZOL groups in the overall study population. However, ER+/HER2- patients younger than age 45 who were treated with ZOL had significantly worse TTR and TTNBR with a trend towards worse TTBR, BCS and OS (TTR: P = 0.024, HR 6.05 [1.26-29.1]; TTNBR: P = 0.026, HR 6.94 [1.26-38.1]; TTBR: P = 0.054, HR 6.01 [0.97-37.1]; BCS: P = 0.138, HR 4.43 [0.62-31.7]; OS: P = 0.138, HR 4.43 [0.62-31.7]). These differences were not seen in older ER+/HER2- patients or triple-negative patients of any age.

CONCLUSION

Addition of ZOL to neoadjuvant therapy did not significantly affect clinical outcomes in the overall study population but was associated with increased extra-skeletal recurrence and a trend towards worse survival in ER+/HER2- patients younger than age 45. These findings suggest caution when using zoledronic acid in young, premenopausal women with locally advanced breast cancer and warrant further investigation. Clinical Trial Registration Number NCT00242203, Date of Registration: 10/17/2005.

Clodronate

Two early observations about the first generation bisphosphonate, clodronate, suggested that it would likely have clinical utility; specifically, it was a more potent anti-resorptive but a less potent inhibitor of mineralisation than its predecessor etidronate. The known mechanism of action differs from that of the later nitrogen-containing bisphosphonates, as clodronate is metabolised intracellularly to a toxic analog of adenosine triphosphate, AppCCl2p, which causes mitochondrial dysfunction, impaired cellular energy metabolism and osteoclast apoptosis. For pre-clinical studies in a variety of disease models, liposomal clodronate has become the agent of choice for macrophage depletion, for example in a recent study to enhance haematopoietic chimerism and donor-specific skin allograft tolerance in a mouse model. For clinical use, clodronate was developed in oral and injectable formulations; while poorly absorbed from the gastro-intestinal tract, its absorption at 1-3% of the administered dose is approximately three-fold higher than for nitrogen-containing bisphosphonates. Following an early setback due to an erroneous association with toxic adverse events, a number of successful clinical studies have established clodronate, predominantly in its oral formulations, as a highly successful treatment in Paget's disease, hypercalcaemia (benign and malignant), multiple myeloma, and early or metastatic breast cancer. Novel uses in other disease areas, including veterinary use, continue to be explored.

Osteoporosis: A Long-Term and Late-Effect of Breast Cancer Treatments

Simple Summary

Osteoporosis is a prevalent condition affecting 200 million individuals world-wide. Estimates are about one in three women will experience a fragility fracture of hip, spine or wrist. Common breast cancer treatments, such as aromatase inhibitors in postmenopausal women and chemotherapy-induced ovarian failure in premenopausal women, cause bone loss that in some women will lead to osteoporosis and fragility fractures. Fragility fractures cause morbidity and mortality and are entirely preventable. Prevention or treatment of osteoporosis includes lifestyle modifications (e.g., reducing smoking and excessive alcohol consumption, and increasing physical activity), taking calcium and vitamin D3, screening for osteoporosis with dual-energy absorptiometry, and treatment, if clinically indicated, with ether oral bisphosphonates, intravenous zoledronic acid, or subcutaneous denosumab. This chapter reviews the pathogenesis of osteoporosis, the magnitude of bone loss related to common breast cancer treatments, osteoporosis risk factor assessment and screening, and the specific drugs to treat or prevent osteoporosis.

Abstract

Osteoporosis is both a long-term effect (occurs during treatment and extends after treatment) and a late-effect (occurs after treatment ends) of breast cancer treatments. The worldwide prevalence of osteoporosis is estimated to be some 200 million patients. About one in three postmenopausal women will experience an osteoporotic (or fragility) fracture of the hip, spine, or wrist. breast cancer treatments, including gonadotropin-releasing hormone (GnRH) agonists, chemotherapy-induced ovarian failure (CIOF), and aromatase inhibitors (AIs), cause bone loss and increase the risks of osteoporosis. Also, breast cancer is a disease of aging, and most of the “one in eight” lifetime risks of breast cancer are in women in their sixth, seventh, and eighth decades. The majority of women diagnosed with breast cancers today will be long-term survivors and experience personal cures. It is the coalescence of osteoporosis with breast cancer, two common and age-related conditions that make osteoporosis relevant in women with breast cancer throughout the continuum from diagnosis, treatment, and survivorship. It is critical to remember that women (and men) will lose bone after age thirty years. However, only certain women will lose bone of sufficient magnitude to merit treatment with anti-osteoporosis drugs. The narrative review is intended for medical, surgical, radiation oncologists, and other mid-level providers, and provides an overview of bone loss and the prevention and treatment of osteoporosis.

Risk factors for bisphosphonate-associated osteonecrosis of the jaw in the prospective randomized trial of adjuvant bisphosphonates for early-stage breast cancer (SWOG 0307)

PURPOSE

Bisphosphonates reduce bone metastases in postmenopausal women with early-stage breast cancer but carry the risk of bisphosphonate-related osteonecrosis of the jaw (BRONJ). We describe risk factors for BRONJ and compare BRONJ provoked by infection or trauma with spontaneous lesions, which carry a better prognosis.

METHODS

SWOG 0307 randomized women with stage I-III breast cancer to receive zoledronic acid (ZA), clodronate (CL), or ibandronate (IB) for 3 years, implemented BRONJ prevention guidelines, and collected information about dental health and development of BRONJ. All statistical tests were two-sided.

RESULTS

Of 6018 women, 48 developed BRONJ. Infection was present in 21 (43.8%). Median time to BRONJ was 2.1 years for ZA, 2.0 years for IB, and 3.4 years for clodronate (p = 0.04). BRONJ was associated with bisphosphonate type (28/2231 (1.26%) for ZA, 8/2235 (0.36%) for CL, 12/1552 (0.77%) for IB), dental calculus (OR 2.03), gingivitis (OR 2.11), moderate/severe periodontal disease (OR 2.87), and periodontitis > 4 mm (OR 2.20) (p < 0.05). Of 57 lesions, BRONJ occurred spontaneously in 20 (35.1%) and was provoked by dental extraction in 20 (35.1%), periodontal disease in 14 (24.6%), denture trauma in 6 (10.5%), and dental surgery in 2 (3.5%). Spontaneous BRONJ occurred more frequently at the mylohyoid ridge. There were no differences in dental disease, infection, or bisphosphonate type between spontaneous and provoked BRONJ.

CONCLUSION

ZA and worse dental health were associated with increased incidence of BRONJ, with a trend toward additive risk when combined. BRONJ incidence was lower than in similar studies, with prevention strategies likely linked to this.

CLINICAL TRIAL NUMBER

NCT00127205 REGISTRATION DATE: July 2005.

Extra-skeletal effects of bisphosphonates

Bisphosphonates (BPs) are pyrophosphate analogues widely used in diseases related to bone loss and increased bone turnover. Their high affinity for bone hydroxyapatite makes them ideal agents for bone diseases, while preventing them from reaching other cells and tissues. Data of the last decade, however, have demonstrated extra-skeletal tissue deposition and a variety of non-skeletal effects have been recently recognized. As such, BPs have been shown to exert anti-tumor, immunomodulatory, anti-inflammatory and anti-diabetic effects. In addition, new delivery systems (liposomes, nanoparticles, hydrogels) are being developed in an effort to expand BPs clinical application to extra-skeletal tissues and enhance their overall therapeutic spectrum and effectiveness. In the present review, we outline current data on extra-skeletal actions of bisphosphonates and attempt to unravel the underlying pathophysiological mechanisms.

Application of the ESMO-Magnitude of Clinical Benefit Scale (V.1.1) to the field of early breast cancer therapies

Click here to listen to the Podcast BACKGROUND: The European Society for Medical Oncology-Magnitude of Clinical Benefit Scale (ESMO-MCBS) is a validated value scale for solid tumour anticancer treatments. Form 1 of the ESMO-MCBS, used to grade therapies with curative intent including adjuvant therapies, has only been evaluated for a limited number of studies. This is the first large-scale field testing in early breast cancer to assess the applicability of the scale to this data set and the reasonableness of derived scores and to identify any shortcomings to be addressed in future modifications of the scale.

METHOD

Representative key studies and meta-analyses of the major modalities of adjuvant systemic therapy of breast cancer were identified for each of the major clinical scenarios (HER2-positive, HER2-negative, endocrine-responsive) and were graded with form 1 of the ESMO-MCBS. These generated scores were reviewed by a panel of experts for reasonableness. Shortcomings and issues related to the application of the scale and interpretation of results were identified and critically evaluated.

RESULTS

Sixty-five studies were eligible for evaluation: 59 individual studies and 6 meta-analyses. These studies incorporated 101 therapeutic comparisons, 61 of which were scorable. Review of the generated scores indicated that, with few exceptions, they generally reflected contemporary standards of practice. Six shortcomings were identified related to grading based on disease-free survival (DFS), lack of information regarding acute and long-term toxicity and an inability to grade single-arm de-escalation scales.

CONCLUSIONS

Form 1 of the ESMO-MCBS is a robust tool for the evaluation of the magnitude of benefit studies in early breast cancer. The scale can be further improved by addressing issues related to grading based on DFS, annotating grades with information regarding acute and long-term toxicity and developing an approach to grade single-arm de-escalation studies.

Phase III Randomized Trial of Bisphosphonates as Adjuvant Therapy in Breast Cancer: S0307

BACKGROUND

Adjuvant bisphosphonates, when given in a low-estrogen environment, can decrease breast cancer recurrence and death. Treatment guidelines include recommendations for adjuvant bisphosphonates in postmenopausal patients. SWOG/Alliance/Canadian Cancer Trials Group/ECOG-ACRIN/NRG Oncology study S0307 compared the efficacy of three bisphosphonates in early-stage breast cancer.

METHODS

Patients with stage I-III breast cancer were randomly assigned to 3 years of intravenous zoledronic acid, oral clodronate, or oral ibandronate. The primary endpoint was disease-free survival (DFS) with overall survival as a secondary outcome. All statistical tests were two-sided.

RESULTS

A total of 6097 patients enrolled. Median age was 52.7 years. Prior to being randomly assigned, 73.2% patients indicated preference for oral vs intravenous formulation. DFS did not differ across arms in a log-rank test (P = .49); 5-year DFS was 88.3% (zoledronic acid: 95% confidence interval [CI] = 86.9% to 89.6%), 87.6% (clodronate: 95% CI = 86.1% to 88.9%), and 87.4% (ibandronate: 95% CI = 85.6% to 88.9%). Additionally, 5-year overall survival did not differ between arms (log rank P = .50) and was 92.6% (zoledronic acid: 95% CI = 91.4% to 93.6%), 92.4% (clodronate: 95% CI = 91.2% to 93.5%), and 92.9% (ibandronate: 95% CI = 91.5% to 94.1%). Bone as first site of recurrence did not differ between arms (P = .93). Analyses based on age and tumor subtypes showed no treatment differences. Grade 3/4 toxicity was 8.8% (zoledronic acid), 8.3% (clodronate), and 10.5% (ibandronate). Osteonecrosis of the jaw was highest for zoledronic acid (1.26%) compared with clodronate (0.36%) and ibandronate (0.77%).

CONCLUSIONS

We found no evidence of differences in efficacy by type of bisphosphonate, either in overall analysis or subgroups. Despite an increased rate of osteonecrosis of the jaw with zoledronic acid, overall toxicity grade differed little across arms. Given that patients expressed preference for oral formulation, efforts to make oral agents available in the United States should be considered.

Current and Emerging Biomarkers Predicting Bone Metastasis Development

Bone is one of the preferential sites of distant metastases from malignant tumors, with the highest prevalence observed in breast and prostate cancers. Patients with bone metastases (BMs) may experience skeletal-related events, such as severe bone pain, pathological fractures, spinal cord compression, and hypercalcemia, with negative effects on the quality of life. In the last decades, a deeper understanding of the molecular mechanisms underlying the BM onset has been gained, leading to the development of bone-targeting agents. So far, most of the research has been focused on the pathophysiology and treatment of BM, with only relatively few studies investigating potential predictors of risk for BM development. The ability to select such "high-risk" patients could allow early identification of those most likely to benefit from interventions to prevent or delay BM. This review summarizes several evidences for the potential use of specific biomarkers able to predict early the BM development.

Management of osteoporosis in women with breast cancer

The screening, prevention and treatment of osteoporosis are similar in women with or without breast cancer. Breast cancer treatments, such as aromatase inhibitors, chemotherapy-induced ovarian failure and gonadotropin-releasing hormone antagonists all decrease estrogen levels, which in turn causes net bone resorption and bone loss. Bone loss over time will be of sufficient magnitude to cause some women to experience fractures. Thus, osteoporosis is an equation; the peak bone mass achieved by age 30 years minus the age-related and menopausal bone loss. Women should have their bone density measured by dual x-ray absorptiometry scans every 2 years. As clinically indicated, women should receive anti-osteoporosis drugs such as zoledronic acid, denosumab or oral bisphosphonates.

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

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

Targeting Tumor Associated Macrophages to Overcome Conventional Treatment Resistance in Glioblastoma

Glioblastoma (GB) is the most common and devastating form of brain cancer. Despite conventional treatments, progression or recurrences are systematic. In recent years, immunotherapies have emerged as an effective treatment in a number of cancers, leaving the question of their usefulness also faced with the particular case of brain tumors. The challenge here is major not only because the brain is the seat of our consciousness but also because of its isolation by the blood-brain barrier and the presence of a unique microenvironment that constitutes the central nervous system (CNS) with very specific constituent or patrolling cells. Much of the microenvironment is made up of immune cells or inflammation. Among these, tumor-associated macrophages (TAMs) are of significant interest as they are often involved in facilitating tumor progression as well as the development of resistance to standard therapies. In this review, the ubiquity of TAMs in GB will be discussed while the specific case of microglia resident in the brain will be also emphasized. In addition, the roles of TAMs as accomplices in the progression of GB and resistance to treatment will be presented. Finally, clinical trials targeting TAMs as a means of treating cancer will be discussed.

Breast cancer outcome in relation to bone mineral density and bisphosphonate use: a sub-study of the DATA trial

Purpose

The phase III DATA study compared 6 and 3 years of adjuvant anastrozole following 2–3 years of tamoxifen in postmenopausal breast cancer patients. This pre-planned side-study assessed the relationship between a reduced bone mineral density (BMD) and distant recurrence-free survival (DRFS), and evaluated the effect of bisphosphonates on DRFS.

Methods

We selected all patients with a BMD measurement within 3 years after randomisation (landmark) without any DRFS events. Kaplan–Meier methods and Cox proportional hazards models were used for analyses.

Results

Of 1860 eligible patients, 1142 had a DEXA scan before the landmark. The BMD was normal in 436 (38.2%) and showed osteopenia in 565 (49.5%) and osteoporosis in 141 (12.3%) patients. After a median follow-up of 5.0 years from the landmark, neither osteopenia nor osteoporosis (compared with normal BMD) were associated with DRFS in both the 6-year [osteopenia HR 0.82 (95% CI 0.45–1.49), osteoporosis HR 1.10 (95% CI 0.26–4.67)] and the 3-year arm [osteopenia HR 0.75 (95% CI 0.40–1.42), osteoporosis HR 1.86 (95% CI 0.43–8.01)]. Moreover, bisphosphonate use did not impact DRFS.

Conclusion

No association was observed between a reduced BMD and DRFS. Neither did we observe an impact of bisphosphonates on DRFS.

Electronic supplementary material

The online version of this article (10.1007/s10549-020-05567-9) contains supplementary material, which is available to authorized users.

Disseminated Tumor Cells and Dormancy in Breast Cancer Progression

Hematogenous dissemination of single cancer cells is a common phenomenon in patients with solid tumors. These cells may experience different fates: most will die during the process; some will grow into metastasis and some will persist in secondary homing sites for many years in a state referred to as dormancy. The mechanisms of this state are still not clear; single cancer cells can survive either by completely withdrawing from the cell cycle or by continuing to proliferate at a slow rate that is counterbalanced by cell death. Another hypothesis assumes that at least some of dormant tumor cells feature stem cell-like characteristics that may contribute to their extremely long half-lives and enhance chemotherapy resistance. Breast cancer is particularly known for prolonged periods of clinical freedom of disease (sometimes up to 20-30 years), followed by a distant relapse. In this chapter, we explore the relationship between the clinical phenomenon of tumor dormancy and the disseminated tumor cells and discuss the potential implications for treatment.

Adjuvant bisphosphonate therapy in early-stage breast cancer-Treating the soil to kill the seed

Bisphosphonates alter the tumor microenvironment, possibly preventing cancer cell growth in the bone. Analyses of data from numerous clinical trials and a large individual patient-level data meta-analysis have suggested an anti-tumor effect for bisphosphonates in patients with early-stage breast cancer who are postmenopausal. The absolute benefit from the use of bisphosphonates on breast cancer-related mortality reduction mirrors that seen with the use of anthracycline-based chemotherapy versus a first-generation chemotherapy regimen (CMF). In this review, we discuss the evidence base for the use of adjuvant bisphosphonates in early-stage breast cancer and provide recommendations for clinical use.

Adjuvant denosumab in early breast cancer (D-CARE): an international, multicentre, randomised, controlled, phase 3 trial

BACKGROUND

Denosumab is a fully human monoclonal antibody that binds to, and inhibits, the receptor activator of RANKL (TNFSF11) and might affect breast cancer biology, as shown by preclinical evidence. We aimed to assess whether denosumab combined with standard-of-care adjuvant or neoadjuvant systemic therapy and locoregional treatments would increase bone metastasis-free survival in women with breast cancer.

METHOD

In this international, double-blind, randomised, placebo-controlled, phase 3 study (D-CARE), patients were recruited from 389 centres in 39 countries. We enrolled women (aged ≥ 18 years) with histologically confirmed stage II or III breast cancer and an Eastern Cooperative Oncology Group performance status of 0 or 1. On eligibility confirmation, investigators at each site telephoned an interactive voice response system to centrally randomly assign patients (1:1) based on a fixed stratified permuted block randomisation list (block size 4) to receive either denosumab (120 mg) or matching placebo subcutaneously every 3-4 weeks, starting with neoadjuvant or adjuvant chemotherapy, for about 6 months and then every 12 weeks for a total duration of 5 years. Stratification factors were breast cancer therapy, lymph node status, hormone receptor and HER2 status, age, and geographical region. The primary endpoint was the composite endpoint of bone metastasis-free survival. This trial is registered with ClinicalTrials.gov, NCT01077154.

FINDINGS

Between June 2, 2010, and Aug 24, 2012, 4509 women were randomly assigned to receive denosumab (n=2256) or placebo (n=2253) and included in the intention-to-treat analysis. The primary analysis of the study was done when all patients had the opportunity to complete 5 years of follow-up with an analysis data cutoff date of Aug 31, 2017. The primary endpoint of bone metastasis-free survival was not significantly different between the groups (median not reached in either group; hazard ratio 0·97, 95% CI 0·82-1·14; p=0·70). The most common grade 3 or worse treatment-emergent adverse events, reported in patients who had at least one dose of the investigational product (2241 patients with denosumab vs 2218 patients with placebo), were neutropenia (340 [15%] vs 328 [15%]), febrile neutropenia (112 [5%] vs 142 [6%]), and leucopenia (62 [3%] vs 61 [3%]). Positively adjudicated osteonecrosis of the jaw occurred in 122 (5%) of 2241 patients treated with denosumab versus four (<1%) of 2218 patients treated with placebo; treatment-emergent hypocalcaemia occurred in 152 (7%) versus 82 (4%). Two treatment-related deaths occurred in the placebo group due to acute myeloid leukaemia and depressed level of consciousness.

INTERPRETATION

Despite preclinical evidence suggesting RANKL inhibition might delay bone metastasis or disease recurrence in patients with early-stage breast cancer, in this study, denosumab did not improve disease-related outcomes for women with high-risk early breast cancer.

FUNDING

Amgen.

Associations Between Serum Bone Biomarkers in Early Breast Cancer and Development of Bone Metastasis: Results From the AZURE (BIG01/04) Trial

Background

Adjuvant therapies can prevent/delay bone metastasis development in breast cancer. We investigated whether serum bone turnover markers in early disease have clinical utility in identifying patients with a high risk of developing bone metastasis.

Methods

Markers of bone formation (N-terminal propeptide of type-1 collagen [P1NP]) and bone resorption (C-telopeptide of type-1 collagen [CTX], pyridinoline cross-linked carboxy-terminal telopeptide of type-1 collagen [1-CTP]) were measured in baseline (pretreatment blood samples from 872 patients from a large randomized trial of adjuvant zoledronic acid (AZURE-ISRCTN79831382) in early breast cancer. Cox proportional hazards regression and cumulative incidence functions (adjusted for factors having a statistically significant effect on outcome) were used to investigate prognostic and predictive associations between recurrence events, bone marker levels, and clinical variables. All statistical tests were two-sided.

Results

When considered as continuous variables (log transformed), P1NP, CTX, and 1-CTP were each prognostic for future bone recurrence at any time (P = .006, P = .009, P = .008, respectively). Harrell’s c-indices were a P1NP of 0.57 (95% confidence interval [CI] = 0.51 to 0.63), CTX of 0.57 (95% CI = 0.51 to 0.62), and 1-CTP of 0.57 (95% CI = 0.52 to 0.63). In categorical analyses based on the normal range, high baseline P1NP (>70 ng/mL) and CTX (>0.299 ng/mL), but not 1-CTP (>4.2 ng/mL), were also prognostic for future bone recurrence (P = .03, P = .03, P = .10, respectively). None of the markers were prognostic for overall distant recurrence; that is, they were bone metastasis specific, and none of the markers were predictive of treatment benefit from zoledronic acid.

Conclusions

Serum P1NP, CTX, and 1-CTP are clinically useful, easily measured markers that show good prognostic ability (though low-to-moderate discrimination) for bone-specific recurrence and are worthy of further study.

Metastatic bone disease: Pathogenesis and therapeutic options: Up-date on bone metastasis management

Bone metastases (BM) are a common complication of cancer, whose management often requires a multidisciplinary approach. Despite the recent therapeutic advances, patients with BM may still experience skeletal-related events and symptomatic skeletal events, with detrimental impact on quality of life and survival. A deeper knowledge of the mechanisms underlying the onset of lytic and sclerotic BM has been acquired in the last decades, leading to the development of bone-targeting agents (BTA), mainly represented by anti-resorptive drugs and bone-seeking radiopharmaceuticals. Recent pre-clinical and clinical studies have showed promising effects of novel agents, whose safety and efficacy need to be confirmed by prospective clinical trials. Among BTA, adjuvant bisphosphonates have also been shown to reduce the risk of BM in selected breast cancer patients, but failed to reduce the incidence of BM from lung and prostate cancer. Moreover, adjuvant denosumab did not improve BM free survival in patients with breast cancer, suggesting the need for further investigation to clarify BTA role in early-stage malignancies. The aim of this review is to describe BM pathogenesis and current treatment options in different clinical settings, as well as to explore the mechanism of action of novel potential therapeutic agents for which further investigation is needed.

Compliance and patient reported toxicity from oral adjuvant bisphosphonates in patients with early breast cancer. A cross sectional study

Background

Adjuvant bisphosphonates (BPs) are recommended as part of routine early breast cancer treatment for many postmenopausal (PM) women within the past year. There is a paucity of ‘real world’ data on compliance and patient satisfaction with oral BPs in this population. The aim of our study was to investigate patient reported compliance and toxicity of these drugs in a retrospective cohort study.

Patients and methods

413 patient were identified as receiving adjuvant oral BPs as part of their breast cancer treatment in the past 12 months from five NHS hospitals. The validated Osteoporosis Patient Treatment Satisfaction Questionnaire (OPSAT-Q) was sent to all suitable patients (n = 389).

Results

295 (76%) of patients responded. Average age was median (range) 67 (35–89). The majority of patients had T1 (52%), N0 (61%) grade 2 (58%) ER positive (87%), HER2 negative (84%) breast cancer and were PM at diagnosis of breast cancer (93%). All patients had been prescribed at least 1 month of oral ibandronate 50 mg daily. Review of items rated on the 7-point scale (1 = very dissatisfied to 7 = very satisfied), the mean item scores ranged from 5.0 (lowest) for time required to take oral BPs, to 6.1 (highest) for how easy it is to remember to take the medication. <10% of patients were extremely bothered by heartburn or stomach upset. 16% of responders stopped oral BPs with 10% of those converting onto IV BPs.

Conclusions

Prevalence of severe side effects in a ‘real world’ population of PM women receiving adjuvant BPs is low and these drugs are generally well accepted and tolerated by patients.

Absolute benefit from adjuvant chemotherapy in contemporary clinical trials: A systemic review and meta-analysis

BACKGROUND

Many adjuvant breast cancer trials have observed smaller than anticipated differences between experimental and control groups. Accurate estimation of the absolute benefits of treatment is essential for the planning of clinical trials.

METHODS

We searched PubMed to identify contemporary randomized trials comparing different adjuvant chemotherapy regimens in breast cancer. The absolute difference in 5-year disease-free survival (DFS) and overall-survival between experimental and control groups were extracted, weighted by individual study sample size and pooled. Analyses were performed for estrogen receptor (ER) negative and ER-positive disease. Meta-regression explored the influence of patients and tumor characteristics and median follow-up on the benefit from treatment.

RESULTS

Analysis included 19 studies comprising 41,564 patients. Studies comparing chemotherapy regimens of different generations showed the largest difference in 5-year DFS (+7.4% for 3rd vs. 2nd generation and +5.9% for 2nd vs. 1st generation for ER-negative disease, and +2.3% for 3rd vs. 2nd generation and +1.8% for 2nd vs. 1st generation for ER-positive disease). Studies comparing chemotherapy regimens from the same generation showed smaller differences in DFS in both subgroups. Meta-regression showed that larger tumors and nodal involvement had significant greater magnitude of effect on 5-year DFS for ER-negative, but not ER-positive disease. Age and menopausal status had no effect in either subgroup.

CONCLUSIONS

Absolute differences between adjuvant chemotherapy regimens of the same generation are small even in ER-negative disease. Enrichment of trials for patients with poor clinical features results in larger magnitudes of benefit from treatment at 5 years in ER-negative, but not ER-positive disease.

Bone-Modifying Agents in Early-Stage and Advanced Breast Cancer

PURPOSE OF REVIEW

Bone-modifying agents have an important role in the treatment of patients with bone mineral density loss, early-stage breast cancer to reduce risk of recurrence, and metastatic breast cancer with bone involvement. Here we review mechanisms of action of these agents and clinical indications for their use.

RECENT FINDINGS

The meta-analysis undertaken by the Early Breast Cancer Trialists' Collaborative Group showed that the use of bisphosphonates was associated with a decreased risk of breast cancer recurrence.

SUMMARY

The effect of bisphosphonates and receptor activator of nuclear factor kappa-B ligand inhibitors on bone health provides an opportunity to decrease the incidence of skeletal-related events and improve cancer outcomes in certain subsets of patients.

Benefits and risks of adjuvant treatment with zoledronic acid in stage II/III breast cancer. 10 years follow-up of the AZURE randomized clinical trial (BIG 01/04)

Adjuvant bisphosphonates improve disease outcomes in postmenopausal early breast cancer (EBC) but the long-term effects are poorly described. The AZURE trial (ISRCTN79831382) was designed to determine whether adjuvant zoledronic acid (ZOL) improves disease outcomes in EBC. Previous analyses showed no effect on overall outcomes but identified benefits in postmenopausal women. Here we present the long-term risks and benefits of adjuvant ZOL with 10-years follow-up.

Patients and methods

3360 patients with stage II/III breast cancer were included in an academic, international, phase III, randomized, open label trial. Patients were followed up on a regular schedule until 10 years. Patients were randomized on a 1:1 basis to standard adjuvant systemic therapy +/− intravenous ZOL 4 mg every 3–4 weeks x6, and then at reduced frequency to complete 5 years treatment. The primary outcome was disease free survival (DFS). Secondary outcomes included invasive DFS (IDFS), overall survival (OS), sites of recurrence, skeletal morbidity and treatment outcomes according to primary tumor amplification of the transcription factor, MAF. Pre-planned subgroup analyses focused on interactions between menopausal status and treatment effects.

Results

With a median follow up of 117 months [IQR 70.4–120.4), DFS and IDFS were similar in both arms (HR_DFS= 0.94, 95%CI = 0.84–1.06, p = 0.340; HR_IDFS= 0.91, 95%CI = 0.82–1.02, p = 0.116). However, outcomes remain improved with ZOL in postmenopausal women (HR_DFS= 0.82, 95%CI = 0.67–1.00; HR_IDFS= 0.78, 95%CI = 0.64–0.94). In the 79% of tested women with a MAF FISH negative tumor, ZOL improved IDFS (HR_IDFS= 0.75, 95%CI = 0.58–0.97) and OS HR_OS= 0.69, 95%CI = 0.50–0.94), irrespective of menopause. ZOL did not improve disease outcomes in MAF FISH + tumors. Bone metastases as a first DFS recurrence (B_DFS) were reduced with ZOL (HR_B-DFS= 0.76, 95%CI = 0.63–0.92, p = 0.005). ZOL reduced skeletal morbidity with fewer fractures and skeletal events after disease recurrence. 30 cases of osteonecrosis of the jaw in the ZOL arm (1.8%) have occurred.

Conclusions

Disease benefits with adjuvant ZOL in postmenopausal early breast cancer persist at 10 years of follow-up. The biomarker MAF identified a patient subgroup that derived benefit from ZOL irrespective of menopausal status.