Direct and indirect anticancer activity of bisphosphonates: a brief review of published literature

Nanomaterials for bone metastasis

Bone metastasis, a prevalent occurrence in primary malignant tumors, is often associated with a grim prognosis. The bone microenvironment comprises various coexisting cell types, working together in a coordinated manner. This dynamic microenvironment plays a pivotal role in the initiation and progression of bone metastases. While cancer therapies have made advancements, the available options for addressing bone metastases remain insufficient. The advent of nanotechnology has ushered in a new era for managing and preventing bone metastases because of the physicochemical and adaptable advantages of nanoplatforms. In this review, we make an introduction of the underlying mechanisms and the current clinical therapies of bone metastases, highlighting the advances of intelligent nanosystems that can stimulate vascular regeneration, promote bone regeneration, eliminate tumor cells, minimize bone damage, and expedite bone healing. The innovation surrounding bone-targeting nanoplatforms presents a fresh approach to the theranostics of bone metastases.

Advancements in Understanding the Hide-and-Seek Strategy of Hibernating Breast Cancer Cells and Their Implications in Oncology from a Broader Perspective: A Comprehensive Overview

Despite recent advancements in technology, breast cancer still poses a significant threat, often resulting in fatal consequences. While early detection and treatments have shown some promise, many breast cancer patients continue to struggle with the persistent fear of the disease returning. This fear is valid, as breast cancer cells can lay dormant for years before remerging, evading traditional treatments like a game of hide and seek. The biology of these dormant breast cancer cells presents a crucial yet poorly understood challenge in clinical settings. In this review, we aim to explore the mysterious world of dormant breast cancer cells and their significant impact on patient outcomes and prognosis. We shed light on the elusive role of the G9a enzyme and many other epigenetic factors in breast cancer recurrence, highlighting its potential as a target for eliminating dormant cancer cells and preventing disease relapse. Through this comprehensive review, we not only emphasise the urgency of unravelling the dynamics of dormant breast cancer cells to improve patient outcomes and advance personalised oncology but also provide a guide for fellow researchers. By clearly outlining the clinical and research gaps surrounding dormant breast cancer cells from a molecular perspective, we aim to inspire further exploration of this critical area, ultimately leading to improved patient care and treatment strategies.

Spectrum of activity and mechanisms of azole-bisphosphonate synergy in pathogenic Candida

Candidiasis places a significant burden on human health and can range from common superficial vulvovaginal and oral infections to invasive diseases with high mortality. The most common Candida species implicated in human disease is Candida albicans, but other species like Candida glabrata are emerging. The use of azole antifungals for treatment is limited by increasing rates of resistance. This study explores repositioning bisphosphonates, which are traditionally used for osteoporosis, as antifungal synergists that can improve and revitalize the use of azoles. Risedronate, alendronate, and zoledronate (ZOL) were tested against isolates from six different species of Candida, and ZOL produced moderate antifungal activity and strong synergy with azoles like fluconazole (FLC), particularly in C. glabrata. FLC:ZOL combinations had increased fungicidal and antibiofilm activity compared to either drug alone, and the combination prevented the development of antifungal resistance. Mechanistic investigations demonstrated that the synergy was mediated by the depletion of squalene, resulting in the inhibition of ergosterol biosynthesis and a compromised membrane structure. In C. glabrata, synergy compromised the function of membrane-bound multidrug transporters and caused an accumulation of reactive oxygen species, which may account for its acute sensitivity to FLC:ZOL. The efficacy of FLC:ZOL in vivo was confirmed in a Galleria mellonella infection model, where combinations improved the survival of larvae infected with C. albicans and C. glabrata to a greater extent than monotherapy with FLC or ZOL, and at reduced dosages. These findings demonstrate that bisphosphonates and azoles are a promising new combination therapy for the treatment of topical candidiasis.

IMPORTANCE

Candida is a common and often very serious opportunistic fungal pathogen. Invasive candidiasis is a prevalent cause of nosocomial infections with a high mortality rate, and mucocutaneous infections significantly impact the quality of life of millions of patients a year. These infections pose substantial clinical challenges, particularly as the currently available antifungal treatment options are limited in efficacy and often toxic. Azoles are a mainstay of antifungal therapy and work by targeting the biosynthesis of ergosterol. However, there are rising rates of acquired azole resistance in various Candida species, and some species are considered intrinsically resistant to most azoles. Our research demonstrates the promising therapeutic potential of synergistically enhancing azoles with non-toxic, FDA-approved bisphosphonates. Repurposing bisphosphonates as antifungal synergists can bypass much of the drug development pipeline and accelerate the translation of azole-bisphosphonate combination therapy.

Managing a Long and Winding Road: Estrogen Receptor-Positive Breast Cancer

We review key topics in the management of estrogen receptor (ER)-positive human epidermal growth factor receptor 2-negative breast cancer. The single biggest challenge in management of this disease is late relapse, and we review new methods for identifying which patients are at risk of late relapse and potential therapeutic approaches in clinical trials. CDK4/6 inhibitors have become a standard treatment option for high-risk patients in both the adjuvant setting and the first-line metastatic setting, and we review data on optimal treatment after progression on CDK4/6 inhibitors. Targeting the estrogen receptor remains the single most effective way of targeting the cancer, and we review the developments in new oral selective ER degraders that are becoming a standard of care in cancers with ESR1 mutations and potential future directions.

Engineering Bifunctional Calcium Alendronate Gene-Delivery Nanoneedle for Synergistic Chemo/Immuno-Therapy Against HER2 Positive Ovarian Cancer

Ovarian cancer is the most lethal gynecological malignancy. Most patients are diagnosed at an advanced stage with widespread peritoneal dissemination and ascites. Bispecific T-cell engagers (BiTEs) have demonstrated impressive antitumor efficacy in hematological malignancies, but the clinical potency is limited by their short half-life, inconvenient continuous intravenous infusion, and severe toxicity at relevant therapeutic levels in solid tumors. To address these critical issues, the design and engineering of alendronate calcium (CaALN) based gene-delivery system is reported to express therapeutic level of BiTE (HER2×CD3) for efficient ovarian cancer immunotherapy. Controllable construction of CaALN nanosphere and nanoneedle is achieved by the simple and green coordination reactions that the distinct nanoneedle-like alendronate calcium (CaALN-N) with a high aspect ratio enabled efficient gene delivery to the peritoneum without system in vivo toxicity. Especially, CaALN-N induced apoptosis of SKOV3-luc cell via down-regulation of HER2 signaling pathway and synergized with HER2×CD3 to generate high antitumor response. In vivo administration of CaALN-N/minicircle DNA encoding HER2×CD3 (MC-HER2×CD3) produces sustained therapeutic levels of BiTE and suppresses tumor growth in a human ovarian cancer xenograft model. Collectively, the engineered alendronate calcium nanoneedle represents a bifunctional gene delivery platform for the efficient and synergistic treatment of ovarian cancer.

Does the number of 6-monthly adjuvant zoledronate infusions received affect treatment efficacy for early breast cancer? A sub-study of ABCSG-12

BACKGROUND

The widespread adoption of adjuvant bisphosphonate therapy for postmenopausal early breast cancer (EBC) patients was based on results of the Early Breast Cancer Trialist Group (EBCTCG) meta-analysis. Despite multiple regimens evaluated, there was no signal of varying efficacy with type, dose/dose intensity of bisphosphonate administration. We evaluated the effect of early treatment cessation using long-term outcome data from the ABCSG-12 trial.

PATIENTS AND METHODS

ABCSG-12 randomized 1803 hormone-receptor positive EBC patients on ovarian suppression between 1999 and 2006 to receive 4 mg zoledronic acid 6-monthly or not (and tamoxifen or anastrozole, 2:2 factorial design). In the current study, we evaluated whether the number of zoledronate infusions had an impact on breast cancer-specific outcomes. We hypothesized that amongst patients who received at least one zoledronate infusion, the number of infusions had no effect on outcomes. Time-to-event endpoints were analysed with Cox models and Kaplan Meier curves starting from a 3-year landmark. BMD analysis was restricted to patients who participated in the BMD sub-study.

RESULTS

725 patients who received at least one zoledronate infusion were included in the time-to-event analysis. There was no statistically significant difference in disease-free or overall survival in the patients who received ≤6 zoledronate infusions (n = 170) compared to those who received ≥7 zoledronate infusions (n = 555).

CONCLUSIONS

Comparable to efforts to de-escalate treatment duration in metastatic bone disease, there was no evidence to indicate that a reduced number of zoledronate infusions is associated with reduced adjuvant efficacy. Further studies to define optimal regimens of adjuvant bone-targeted therapies are required.

The Antineoplastic Effect of Carboplatin Is Potentiated by Combination with Pitavastatin or Metformin in a Chemoresistant High-Grade Serous Carcinoma Cell Line

The combination of Carboplatin with Paclitaxel is the mainstay treatment for high-grade serous carcinoma; however, many patients with advanced disease undergo relapse due to chemoresistance. Drug repurposing coupled with a combination of two or more compounds with independent mechanisms of action has the potential to increase the success rate of the antineoplastic treatment. The purpose of this study was to explore whether the combination of Carboplatin with repurposed drugs led to a therapeutic benefit. Hence, we assessed the cytotoxic effects of Carboplatin alone and in combination with several repurposed drugs (Pitavastatin, Metformin, Ivermectin, Itraconazole and Alendronate) in two tumoral models, i.e., Carboplatin (OVCAR8) and Carboplatin-Paclitaxel (OVCAR8 PTX R P) chemoresistant cell lines and in a non-tumoral (HOSE6.3) cell line. Cellular viability was measured using the Presto Blue assay, and the synergistic interactions were evaluated using the Chou-Talalay, Bliss Independence and Highest Single Agent reference models. Combining Carboplatin with Pitavastatin or Metformin displayed the highest cytotoxic effect and the strongest synergism among all combinations for OVCAR8 PTX R P cells, resulting in a chemotherapeutic effect superior to Carboplatin as a single agent. Concerning HOSE6.3 cells, combining Carboplatin with almost all the repurposed drugs demonstrated a safe pharmacological profile. Overall, we propose that Pitavastatin or Metformin could act synergistically in combination with Carboplatin for the management of high-grade serous carcinoma patients with a Carboplatin plus Paclitaxel resistance profile.

Cellular Carcinogenesis: Role of Polarized Macrophages in Cancer Initiation

Simple Summary

Inflammation is a hallmark of many cancers. Macrophages are key participants in innate immunity and important drivers of inflammation. When chronically polarized beyond normal homeostatic responses to infection, injury, or aging, macrophages can express several pro-carcinogenic phenotypes. In this review, evidence supporting polarized macrophages as endogenous sources of carcinogenesis is discussed. In addition, the depletion or modulation of macrophages by small molecule inhibitors and probiotics are reviewed as emerging strategies in cancer prevention.

Abstract

Inflammation is an essential hallmark of cancer. Macrophages are key innate immune effector cells in chronic inflammation, parainflammation, and inflammaging. Parainflammation is a form of subclinical inflammation associated with a persistent DNA damage response. Inflammaging represents low-grade inflammation due to the dysregulation of innate and adaptive immune responses that occur with aging. Whether induced by infection, injury, or aging, immune dysregulation and chronic macrophage polarization contributes to cancer initiation through the production of proinflammatory chemokines/cytokines and genotoxins and by modulating immune surveillance. This review presents pre-clinical and clinical evidence for polarized macrophages as endogenous cellular carcinogens in the context of chronic inflammation, parainflammation, and inflammaging. Emerging strategies for cancer prevention, including small molecule inhibitors and probiotic approaches, that target macrophage function and phenotype are also discussed.

Bisphosphonate treatment is associated with decreased mortality rates in patients after osteoporotic vertebral fracture

The aim of this study is to investigate the effect of bisphosphonate (BP) on mortality after osteoporotic vertebral fracture (OVF). BP medication (hazard ratios = 0.593; 95%CI: 0.361-0.976) was significantly associated with reduced all-cause mortality after OVF.

PURPOSE

Osteoporotic vertebral fracture (OVF) is the most common type of fragility fracture. Bisphosphonate (BP) medication was suggested to have positive effects on both fracture prevention and recovery outcomes. The aim of this study is to investigate the effect of BP on mortality after OVF.

METHODS

This cohort study involved 535 patients (170 males and 365 females), aged ≥ 65 years (mean age: 82.6 ± 7.0 years, mean follow-up periods: 33.0 ± 25.8 months) who were hospitalized after OVF from January 2011 to December 2019 at a public hospital. Patients treated with PTH (parathyroid hormone), PTH or PTHrp analogues, denosumab, and selective estrogen receptor modulators were excluded. Kaplan-Meier survival curves on mortality of patients with OVF with and without BP treatment were prepared, and log-rank tests were performed. Cox proportional hazards model was used to identify factors associated with mortality after OVF.

RESULTS

This study included 163 (30.5%) patients treated with BP. Kaplan-Meier survival curves showed that the mortality rate after OVF was significantly lower in patients treated with BP (P < 0.001). Cox proportional hazards model showed that older age (hazard ratios [HR] = 1.066; 95%CI:1.035-1.103), male sex (HR = 2.248; 95%CI:1.427-3.542), malnutrition (geriatric nutritional risk index < 92) (HR = 1.691; 95%CI:1.005-2.846), BP medication (HR = 0.593; 95%CI: 0.361-0.976), and Japanese Orthopaedic Association score at discharge (HR = 0.941; 95%CI: 0.892-0.993) were significantly associated with all-cause mortality after OVF.

CONCLUSIONS

BP medication is beneficial not only for fracture prevention but also for mortality after OVF.

A Review Into the Effects of Pamidronic Acid and Zoledronic Acid on the Oral Mucosa in Medication-Related Osteonecrosis of the Jaw

Medication-related osteonecrosis of the jaw (MRONJ) is a growing problem without an effective treatment, presenting as necrotic bone sections exposed via lesions in the overlying soft tissue. There is currently a lack of clarity on how the factors involved in MRONJ development and progression contribute to disease prognosis and outcomes. Bisphosphonates (BPs), the most common cause of MRONJ, affect bone remodeling, angiogenesis, infection, inflammation and soft tissue toxicity, all of which contribute to MRONJ development. This article reviews the cellular mechanisms through which BPs contribute to MRONJ pathology, with a focus on the effects on cells of the oral mucosa. BPs have been shown to reduce cell viability, reduce proliferation, and increase apoptosis in oral keratinocytes and fibroblasts. BPs have also been demonstrated to reduce epithelial thickness and prevent epithelial formation in three-dimensional tissue engineered models of the oral mucosa. This combination of factors demonstrates how BPs lead to the reduced wound healing seen in MRONJ and begins to uncover the mechanisms through which these effects occur. The evidence presented here supports identification of targets which can be used to develop novel treatment strategies to promote soft tissue wound healing and restore mucosal coverage of exposed bone in MRONJ.

Endometrial cancer

Although endometrial cancer management remains challenging, a deeper understanding of the genetic diversity as well as the drivers of the various pathogenic states of this disease has led to development of divergent management approaches in an effort to improve therapeutic precision in this complex malignancy. This comprehensive review provides an update on the epidemiology, pathophysiology, diagnosis and molecular classification, recent advancements in disease management, as well as important patient quality-of-life considerations and emerging developments in the rapidly evolving therapeutic landscape of endometrial cancers.

A Review on Re-Packaging of Bisphosphonates Using Biomaterials

The need for bone repair and insight into new regeneration therapies as well as improvement of existing regeneration routes is constantly increasing as a direct consequence of the rise in the number of trauma victims, musculoskeletal disorders, and increased life expectancy. Bisphosphonates (BPs) have emerged as a class of drugs with proven efficacy against many bone disorders. The most recent ability of this class of drugs is being explored in its anti-cancer ability. However, despite the pharmacological success, there are certain shortcomings that have circumvented this class of the drug. The mediation of biomaterials in delivering bisphosphonates has greatly helped in overcoming some of these shortcomings. This article is focused on reviewing the benefits the bisphosphonates have provided upon getting delivered via the use of biomaterials. Furthermore, the role of bisphosphonates as a potent anticancer agent is also accounted. It is witnessed that employing engineering tools in combination with therapeutics has the potential to provide solutions to bone loss from degenerative, surgical, or traumatic processes, and also aid in accelerating the healing of large bone fractures and problematic non-union fractures. The role of nanotechnology in enhancing the efficacy of the bisphosphonates is also reviewed and innovative approaches are identified.

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.

Novel approaches to target the microenvironment of bone metastasis

Bone metastases are a frequent and severe complication of advanced-stage cancers. Breast and prostate cancers, the most common malignancies in women and men, respectively, have a particularly high propensity to metastasize to bone. Conceptually, circulating tumour cells (CTCs) in the bloodstream and disseminated tumour cells (DTCs) in the bone marrow provide a snapshot of the dissemination and colonization process en route to clinically apparent bone metastases. Many cell types that constitute the bone microenvironment, including osteoblasts, osteocytes, osteoclasts, adipocytes, endothelial cells, haematopoietic stem cells and immune cells, engage in a dialogue with tumour cells. Some of these cells modify tumour biology, while others are disrupted and out-competed by tumour cells, thus leading to distinct phases of tumour cell migration, dormancy and latency, and therapy resistance and progression to overt bone metastases. Several current bone-protective therapies act by interrupting these interactions, mainly by targeting tumour cell-osteoclast interactions. In this Review, we describe the functional roles of the bone microenvironment and its components in the initiation and propagation of skeletal metastases, outline the biology and clinical relevance of CTCs and DTCs, and discuss established and future therapeutic approaches that specifically target defined components of the bone microenvironment to prevent or treat skeletal metastases.

Bisphosphonate Use Does Not Impact Survival in Patients with Pancreatic Cancer: A Propensity Score Matching Analysis

Background/Aims

Bisphosphonates are increasingly recognized for their anti-neoplastic properties, which are the result of their action on the mevalonate pathway. Our primary aim was to investigate the association between bisphosphonate use and survival in patients with pancreatic cancer. Since statins also act on the mevalonate pathway, we also investigated the effect of the combined use of bisphosphonates and statins on survival.

Methods

The Surveillance, Epidemiology, and End Results registry (SEER)-Medicare linked database was used to identify patients with pancreatic ductal adenocarcinoma (PDAC) between 2007 and 2015. Kaplan-Meier models were used to examine the association between survival with bisphosphonate use alone and in combination with statins within 1 year prior to the diagnosis of PDAC. Propensity score matching analysis and Cox-proportional hazard models were used to determine the association between overall survival with bisphosphonate use alone and combined with statins, after adjusting for relevant confounders, such as the Charlson comorbidity index score, stage, treatment, sociodemographic characteristics, and propensity score.

Results

In total, 13,639 patients with PDAC were identified, and 1,203 (8.82%) used bisphosphonates. There was no difference in the mean survival duration between bisphosphonate users (7.27 months) and nonusers (7.25 months, p=0.61). After adjustment for confounders, bisphosphonate use was still not associated with improved survival (hazard ratio, 1.00; 95% confidence interval, 0.93 to 1.08; p=0.96). Combined bisphosphonate and statin use was also not associated with improved survival (hazard ratio, 0.97; 95% confidence interval, 0.87 to 1.07; p=0.48) after adjustment for confounders.

Conclusions

Our findings suggest that the use of bisphosphonates, whether alone or in combination with statins, does not confer a survival advantage in patients with PDAC. (Gut Liver 2021;15-790)

Cellular Fitness Phenotypes of Cancer Target Genes from Oncobiology to Cancer Therapeutics

To define the growing significance of cellular targets and/or effectors of cancer drugs, we examined the fitness dependency of cellular targets and effectors of cancer drug targets across human cancer cells from 19 cancer types. We observed that the deletion of 35 out of 47 cellular effectors and/or targets of oncology drugs did not result in the expected loss of cell fitness in appropriate cancer types for which drugs targeting or utilizing these molecules for their actions were approved. Additionally, our analysis recognized 43 cellular molecules as fitness genes in several cancer types in which these drugs were not approved, and thus, providing clues for repurposing certain approved oncology drugs in such cancer types. For example, we found a widespread upregulation and fitness dependency of several components of the mevalonate and purine biosynthesis pathways (currently targeted by bisphosphonates, statins, and pemetrexed in certain cancers) and an association between the overexpression of these molecules and reduction in the overall survival duration of patients with breast and other hard-to-treat cancers, for which such drugs are not approved. In brief, the present analysis raised cautions about off-target and undesirable effects of certain oncology drugs in a subset of cancers where the intended cellular effectors of drug might not be good fitness genes and that this study offers a potential rationale for repurposing certain approved oncology drugs for targeted therapeutics in additional cancer types.

Palbociclib with adjuvant endocrine therapy in early breast cancer (PALLAS): interim analysis of a multicentre, open-label, randomised, phase 3 study

BACKGROUND

Palbociclib added to endocrine therapy improves progression-free survival in hormone-receptor-positive, HER2-negative, metastatic breast cancer. The PALLAS trial aimed to investigate whether the addition of 2 years of palbociclib to adjuvant endocrine therapy improves invasive disease-free survival over endocrine therapy alone in patients with hormone-receptor-positive, HER2-negative, early-stage breast cancer.

METHODS

PALLAS is an ongoing multicentre, open-label, randomised, phase 3 study that enrolled patients at 406 cancer centres in 21 countries worldwide with stage II-III histologically confirmed hormone-receptor-positive, HER2-negative breast cancer, within 12 months of initial diagnosis. Eligible patients were aged 18 years or older with an Eastern Cooperative Oncology Group performance score of 0 or 1. Patients were randomly assigned (1:1) in permuted blocks of random size (4 or 6), stratified by anatomic stage, previous chemotherapy, age, and geographical region, by use of central telephone-based and web-based interactive response technology, to receive either 2 years of palbociclib (125 mg orally once daily on days 1-21 of a 28-day cycle) with ongoing standard provider or patient-choice adjuvant endocrine therapy (tamoxifen or aromatase inhibitor, with or without concurrent luteinising hormone-releasing hormone agonist), or endocrine therapy alone, without masking. The primary endpoint of the study was invasive disease-free survival in the intention-to-treat population. Safety was assessed in all randomly assigned patients who started palbociclib or endocrine therapy. This report presents results from the second pre-planned interim analysis triggered on Jan 9, 2020, when 67% of the total number of expected invasive disease-free survival events had been observed. The trial is registered with ClinicalTrials.gov (NCT02513394) and EudraCT (2014-005181-30).

FINDINGS

Between Sept 1, 2015, and Nov 30, 2018, 5760 patients were randomly assigned to receive palbociclib plus endocrine therapy (n=2883) or endocrine therapy alone (n=2877). At the time of the planned second interim analysis, at a median follow-up of 23·7 months (IQR 16·9-29·2), 170 of 2883 patients assigned to palbociclib plus endocrine therapy and 181 of 2877 assigned to endocrine therapy alone had invasive disease-free survival events. 3-year invasive disease-free survival was 88·2% (95% CI 85·2-90·6) for palbociclib plus endocrine therapy and 88·5% (85·8-90·7) for endocrine therapy alone (hazard ratio 0·93 [95% CI 0·76-1·15]; log-rank p=0·51). As the test statistic comparing invasive disease-free survival between groups crossed the prespecified futility boundary, the independent data monitoring committee recommended discontinuation of palbociclib in patients still receiving palbociclib and endocrine therapy. The most common grade 3-4 adverse events were neutropenia (1742 [61·3%] of 2840 patients on palbociclib and endocrine therapy vs 11 [0·3%] of 2903 on endocrine therapy alone), leucopenia (857 [30·2%] vs three [0·1%]), and fatigue (60 [2·1%] vs ten [0·3%]). Serious adverse events occurred in 351 (12·4%) of 2840 patients on palbociclib plus endocrine therapy versus 220 (7·6%) of 2903 patients on endocrine therapy alone. There were no treatment-related deaths.

INTERPRETATION

At the planned second interim analysis, addition of 2 years of adjuvant palbociclib to adjuvant endocrine therapy did not improve invasive disease-free survival compared with adjuvant endocrine therapy alone. On the basis of these findings, this regimen cannot be recommended in the adjuvant setting. Long-term follow-up of the PALLAS population and correlative studies are ongoing.

FUNDING

Pfizer.

The role of the thymus in allogeneic bone marrow transplantation and the recovery of the peripheral T-cell compartment

As the thymus represents the primary site of T-cell development, optimal thymic function is of paramount importance for the successful reconstitution of the adaptive immunity after allogeneic hematopoietic stem cell transplantation. Thymus involutes as part of the aging process and several factors, including previous chemotherapy treatments, conditioning regimen used in preparation to the allograft, occurrence of graft-versus-host disease, and steroid therapy that impair the integrity of the thymus, thus affecting its role in supporting T-cell neogenesis. Although the pathways governing its regeneration are still poorly understood, the thymus has a remarkable capacity to recover its function after damage. Measurement of both recent thymic emigrants and T-cell receptor excision circles is valuable tools to assess thymic output and gain insights on its function. In this review, we will extensively discuss available data on factors regulating thymic function after allogeneic hematopoietic stem cell transplantation, as well as the strategies and therapeutic approaches under investigation to promote thymic reconstitution and accelerate immune recovery in transplanted patients, including the use of cytokines, sex-steroid ablation, precursor T-cells, and thymus bioengineering. Although none of them is routinely used in the clinic, these approaches have the potential to enhance thymic function and immune recovery, not only in patients given an allograft but also in other conditions characterized by immune deficiencies related to a defective function of the thymus.

Drug-repositioning screening identified fludarabine and risedronic acid as potential therapeutic compounds for malignant pleural mesothelioma

Objectives Malignant pleural mesothelioma (MPM) is an occupational disease mainly due to asbestos exposure. Effective therapies for MPM are lacking, making this tumour type a fatal disease. Materials and Methods In order to meet this need and in view of a future "drug repositioning" approach, here we screened five MPM (Mero-14, Mero-25, IST-Mes2, NCI-H28 and MSTO-211H) and one SV40-immortalized mesothelial cell line (MeT-5A) as a non-malignant model, with a library of 1170 FDA-approved drugs. Results Among several potential compounds, we found that fludarabine (F-araA) and, to a lesser extent, risedronic acid (RIS) were cytotoxic in MPM cells, in comparison to the non-malignant Met-5A cells. In particular, F-araA reduced the proliferation and the colony formation ability of the MPM malignant cells, in comparison to the non-malignant control cells, as demonstrated by proliferation and colony formation assays, in addition to measurement of the phospho-ERK/total-ERK ratio. We have shown that the response to F-araA was not dependent upon the expression of DCK and NT5E enzymes, nor upon their functional polymorphisms (rs11544786 and rs2295890, respectively). Conclusion This drug repositioning screening approach has identified that F-araA could be therapeutically active against MPM cells, in addition to other tumour types, by inhibiting STAT1 expression and nucleic acids synthesis. Further experiments are required to fully investigate this.

Bisphosphonate-based nanocomposite hydrogels for biomedical applications

Nanocomposite hydrogels consist of polymeric network embedded with functional nanoparticles or nanostructures, which not only contribute to the enhanced mechanical properties but also exhibit the bioactivities for regulating cell behavior. Bisphosphonates (BPs) are capable of coordinating with various metal ions and modulating bone homeostasis. Thanks to the inherent dynamic properties of metal-ligand coordination bonds, BP-based nanocomposite hydrogels possess tunable mechanical properties, highly dynamic structures, and the capability to mediate controlled release of encapsulated therapeutic agents, thereby making them highly versatile for various biomedical applications. This review presents the comprehensive overview of recent developments in BP-based nanocomposite hydrogels with an emphasis on the properties of embedded nanoparticles (NPs) and interactions between hydrogel network and NPs. Furthermore, various challenges in the biomedical applications of these hydrogels are discussed to provide an outlook of potential clinical translation.

Anti-tumor effects of mevalonate pathway inhibition in ovarian cancer

BACKGROUND

Ovarian cancer remains the most fatal gynecological malignancy. Current therapeutic options are limited due to late diagnosis in the majority of the cases, metastatic spread to the peritoneal cavity and the onset of chemo-resistance. Thus, novel therapeutic approaches are required. Statins and amino-bisphosphonates are inhibitors of the mevalonate pathway, which is a fundamental pathway of cellular metabolism, essential for cholesterol production and posttranslational protein farnesylation and geranylgeranylation. While this pathway has emerged as a promising treatment target in several human malignancies, its potential as a therapeutic approach in ovarian cancer is still not fully understood.

METHODS

Human ovarian cancer cell lines (IGROV-1, A2780, A2780cis) were treated with increasing concentrations (0.5-100 μM) of statins (simvastatin, atorvastatin, rosuvastatin) and zoledronic acid. Effects on cell vitality and apoptosis were assessed using Cell Titer Blue®, Caspase 3/7 Glo®, clonogenic assays as well as cleaved poly (ADP-ribose) polymerase (cPARP) detection. The inhibition of the mevalonate pathway was confirmed using Western Blot of unprenylated Ras and Rap1a proteins. Quantitative real-time PCR and ELISA were used to analyze modulations on several key regulators of ovarian cancer tumorigenesis.

RESULTS

The treatment of IGROV-1 and A2780 cells with statins and zoledronic acid reduced vitality (by up to 80%; p < 0.001) and induced apoptosis by up to 8-folds (p < 0.001) in a dose-dependent fashion. Rescue experiments using farnesyl pyrophosphate or geranylgeranyl pyrophosphate evidenced that blocked geranylgeranylation is the major underlying mechanism of the pro-apoptotic effects. Gene expression of the tumor-promoting cytokines and mediators, such as transforming growth factor (TGF)-β1, vascular endothelial growth factor (VEGF), interleukin (IL)-8, and IL-6 were significantly suppressed by statins and zoledronic acid by up to 90% (p < 0.001). For all readouts, simvastatin was most potent of all agents used. Cisplatin-resistant A2780cis cells showed a relative resistance to statins and zoledronic acid. However, similar to the effects in A2780 cells, simvastatin and zoledronic acid significantly induced caspase 3/7 activation (6-folds; p < 0.001).

CONCLUSION

Our in vitro findings point to promising anti-tumor effects of statins and zoledronic acid in ovarian cancer and warrant additional validation in preclinical and clinical settings.

Survival in older women with early stage breast cancer receiving low-dose bisphosphonates or denosumab

BACKGROUND

Bisphosphonates and denosumab, as adjuvant therapy in breast cancer, have been associated in some studies with improved cancer outcomes. The potential benefits of these drugs used at the lower doses commonly given for osteoporosis have not been established. The objective of this study was to investigate the association between therapy with bone-modifying agents (BMAs) and survival in older women with early breast cancer.

METHODS

The authors conducted a retrospective cohort study of women aged ≥66 years with breast cancer who were included in the Surveillance, Epidemiology, and End Results and Texas Cancer Registry Medicare-linked databases. Associations were examined between the receipt of BMAs at dosages indicated for osteoporosis within 2 years after diagnosis and overall and breast cancer-specific survival. Cox proportional hazards models and propensity score adjustment and matching were used for the analyses.

RESULTS

Of the 37,724 women included, 7925 (21%) received at least 6 months of a BMA within the first 2 years of breast cancer diagnosis, including bisphosphonates only in 6898 women (80.7%), denosumab only in 1204 (15.2%), and both classes of BMAs in 323 (4.1%). The median follow-up was 64 months. The receipt of a bisphosphonate was associated with improved overall survival (hazard ratio [HR], 0.87; 95% CI, 0.82-0.93) and breast cancer-specific survival (HR, 0.77; 95% CI, 0.64-0.92) after multivariable adjustment. Benefits were primarily seen for patients who had stage II and III disease. No benefits were observed with denosumab (stage II: HR, 1.05 [95% CI, 0.90-1.22]; stage III: HR, 1.09 [95% CI, 0.66-1.82]).

CONCLUSIONS

Bisphosphonates at the doses recommended for osteoporosis are associated with improved survival in older postmenopausal women with early breast cancer.

Cholesterol and beyond - The role of the mevalonate pathway in cancer biology

Cancer is a multifaceted global disease. Transformation of a normal to a malignant cell takes several steps, including somatic mutations, epigenetic alterations, metabolic reprogramming and loss of cell growth control. Recently, the mevalonate pathway has emerged as a crucial regulator of tumor biology and a potential therapeutic target. This pathway controls cholesterol production and posttranslational modifications of Rho-GTPases, both of which are linked to several key steps of tumor progression. Inhibitors of the mevalonate pathway induce pleiotropic antitumor-effects in several human malignancies, identifying the pathway as an attractive candidate for novel therapies. In this review, we will provide an overview about the role and regulation of the mevalonate pathway in certain aspects of cancer initiation and progression and its potential for therapeutic intervention in oncology.

Bisphosphonates-much more than only drugs for bone diseases

α,α-Bisphosphonates (BPs) are well established in the treatment of bone diseases such as osteoporosis and Paget's disease. Their successful application originates from their high affinity to hydroxyapatite. While the initially appreciated features of BPs are already beneficial to many patients, recent developments have further expanded their pleiotropic applications. This review describes the background of the interactions of BPs with bone cells that form the basis of the classical treatment. A better understanding of the mechanism behind their interactions allows for the parallel application of BPs against bone cancer and metastases followed by palliative pain relief. Targeted therapy with bone-seeking BPs coupled with a diagnostic agent in one particle resulted in theranostics which is also described here. For example, in such a system, BP moieties are bound to contrast agents used in magnetic resonance imaging or radionuclides used in positron emission tomography. In addition, another example of the pleiotropic function of BPs which involves targeting the imaging agents to bone tissues accompanied by pain reduction is presented in this work.

The ABC subfamily A transporters: Multifaceted players with incipient potentialities in cancer

Overexpression of ATP-binding cassette (ABC) transporters is a cause of drug resistance in a plethora of tumors. More recent evidence indicates additional contribution of these transporters to other processes, such as tumor cell dissemination and metastasis, thereby extending their possible roles in tumor progression. While the role of some ABC transporters, such as ABCB1, ABCC1 and ABCG2, in multidrug resistance is well documented, the mechanisms by which ABC transporters affect the proliferation, differentiation, migration and invasion of cancer cells are still poorly defined and are frequently controversial. This review, summarizes recent advances that highlight the role of subfamily A members in cancer. Emerging evidence highlights the potential value of ABCA members as biomarkers of risk and response in different tumors, but information is disperse and very little is known about their possible mechanisms of action. The only clear evidence is that ABCA members are involved in lipid metabolism and homeostasis. In particular, the relationship between ABCA1 and cholesterol is becoming evident in different fields of biology, including cancer. In parallel, emerging findings indicate that cholesterol, the main component of cell membranes, can influence many physiological and pathological processes, including cell migration, cancer progression and metastasis. This review aims to link the dispersed knowledge regarding the relationship of ABCA members with lipid metabolism and cancer in an effort to stimulate and guide readers to areas that the writers consider to have significant impact and relevant potentialities.

Multiple myeloma increases nerve growth factor and other pain-related markers through interactions with the bone microenvironment

Interactions between multiple myeloma (MM) and bone marrow (BM) are well documented to support tumour growth, yet the cellular mechanisms underlying pain in MM are poorly understood. We have used in vivo murine models of MM to show significant induction of nerve growth factor (NGF) by the tumour-bearing bone microenvironment, alongside other known pain-related characteristics such as spinal glial cell activation and reduced locomotion. NGF was not expressed by MM cells, yet bone stromal cells such as osteoblasts expressed and upregulated NGF when cultured with MM cells, or MM-related factors such as TNF-α. Adiponectin is a known MM-suppressive BM-derived factor, and we show that TNF-α-mediated NGF induction is suppressed by adiponectin-directed therapeutics such as AdipoRON and L-4F, as well as NF-κB signalling inhibitor BMS-345541. Our study reveals a further mechanism by which cellular interactions within the tumour-bone microenvironment contribute to disease, by promoting pain-related properties, and suggests a novel direction for analgesic development.

Biological effects of aromatic bis[aminomethylidenebis(phosphonic)] acids in osteoclast precursors in vitro

Nitrogen-containing bisphosphonates (N-BPs) inhibit bone resorption by preventing osteoclast activity. Most clinically used BPs are hydroxybisphosphonates with the exception of incadronate, which belongs to the class of aminomethylidenebisphosphonic acids. The aim of this study was to evaluate the antiproliferative activity of two previously reported aminobisphosphonates (WG8185B2 and WG9001B) in combination with doxorubicin and cisplatin toward J774E cells (a model of osteoclast precursors in vitro). WG8185B2 and WG9001B BPs enhanced the cytotoxic activity of doxorubicin and cisplatin, especially when applied 24 hr prior to cytostatics. The antiproliferative effect of studied BPs was related to the changes in cell cycle progression. WG8185B2 leads to significant accumulation of J774E cells in S phase, whereas WG9001B causes transient arrest in G₂ /M phase, followed by an increase in the percentage of cells in S phase. Moreover, WG8185B2 and WG9001B BPs showed enhanced proapoptotic activity in osteoclast precursors, which was manifested by an increase in caspase-3 activity and percentage of apoptotic cells. In addition, both compounds influenced the motility of J774E cells. The exact molecular mechanism of action of examined BPs remains to be determined; however, results show an interesting biological activity of these compounds, which may be of interest in the context of antiresorptive therapy.

Bisphosphonates and primary breast cancer risk: an updated systematic review and meta-analysis involving 963,995 women

Importance

Prevention of primary breast cancer (BCa) in women is of great public health importance. The existing results from observational epidemiologic studies focused on the association between bisphosphonates and primary BCa risk have been inconsistent.

Objective

To update this systematic review and meta-analysis to assess the effect of bisphosphonates on primary BCa risk.

Data sources

We comprehensively searched MEDLINE, EMBASE, Cochrane libraries, ProQuest, and Web of Science through June 25, 2018 for relevant studies.

Study selection

Epidemiological studies that assessed the effect of bisphosphonates on the risk of primary BCa in women.

Data extraction and synthesis

We reported this meta-analysis according to the PRISMA guidelines. Available multivariable-adjusted effect estimates and corresponding 95% CIs were pooled with a random-effects model.

Main outcomes and measures

The prespecified main outcome was the risk of primary BCa.

Results

In total, five cohort studies involving 657,558 women and 12,991 primary BCa patients, three population-based case-control studies involving 54,701 primary BCa cases and 237,962 healthy controls and two randomized controlled trials (RCTs) involving 13,774 women and 165 primary BCa patients were included in this meta-analysis. Bisphosphonates were associated with a 12% decreased risk of primary BCa (RR, 0.88; 95% CI, 0.83–0.94). However, when we analyzed study designs separately, the pooled results from observational studies were inconsistent with that from RCTs. The observed association of primary BCa risk with long-term use (≥1 year) of bisphosphonates seemed to be more robust and stronger than that of short-term use (<1 year) (RR, 0.75; 95% CI, 0.66–0.84; and 0.90; 95% CI, 0.84–0.97; respectively).

Conclusion

This meta-analysis adds to the body of evidence for an association between bisphosphonates and a significantly decreased risk of primary BCa. However, future large-scale RCTs are required to validate this concern.

Design, synthesis and biological evaluation of novel α-aminophosphonate oxadiazoles via optimized iron triflate catalyzed reaction as apoptotic inducers

α-aminophosphonate oxadiazoles (5a-m) were prepared in high yields by reacting of 1,3,4-oxadiazole acetohydrazide (3) with appropriate aldehydes and diethyl phosphite under Kabachnik-Fields conditions using Iron triflate as a catalyst. The reaction conditions were optimized using D-optimal experimental design. Possible reaction mechanisms were considered, and structures of the new products were based upon compatible elementary and spectroscopic evidence. In vitro antitumor activities of these compounds were evaluated against human cancer cell lines of colon (HCT116), breast (MCF7) and liver (HepG2) and compared with anticancer drug, Doxorubicin, employing standard MTT assay. Compounds 5i and 5l demonstrated good antiproliferative activities against HCT116 tumor cells comparable to doxorubicin with low cytotoxicity towards normal fetal colon cell (FHC). Additionally, their capacity to activate apoptosis cascade was studied in HCT116 cell line by investigating the activation of proteolytic caspases cascade, the levels of Cytochrome C, Bax and Bcl-2. Active caspase-3 level was enhanced by 6-8-folds in HCT116 cell line when stimulated with compounds 5i and 5l compared to the control. The level of Caspases 8 & 9 was also increased signifying that intrinsic and extrinsic pathways are both activated. They also induced Bax and down regulated Bcl-2 protein level in addition to over-expressing Cytochrome C level in HCT116 cell line. Also, HCT116 cell cycle was mainly arrested at the Pre-G1 and G2/M phases when treated with compounds 5i and 5l.

Antiproliferative and antimigratory activities of bisphosphonates in human breast cancer cell line MCF-7

Bisphosphonates (BPs) are antiresorptive drugs that act as effective inhibitors of cancer cell proliferation. However, not all bisphosphonates are equally effective against breast cancer cells in vitro. The present study investigated the extent to which three BPs decrease the viability of MCF-7 human breast cancer cells, stimulate cell apoptosis and inhibit cell migration by modulating proteins in the mevalonate pathway. The three BPs exerted direct anticancer effects against MCF-7 cells in a dose- and time-dependent manner, with pamidronate demonstrating the highest efficacy. In addition, the BPs inhibited colony formation ability. The activity of BPs against MCF-7 cells was inhibited by the mevalonate product geranylgeranyl pyrophosphate, which was potentiated by doxorubicin. It was also identified that BPs modulated Ras-related C3 botulinum toxin substrate 1, Ras homolog gene family member A and cell division control protein 42 homolog gene expression. Consistent with the observed growth inhibitory effects, BPs also inhibited the cell cycle by promoting G1 phase arrest and the downregulation of cyclin D1 and upregulation of p21. Additionally, BPs were revealed to induce reactive oxygen species expression, caspase-3 activity and increase the mitochondrial transmembrane potential, which was associated with apoptosis. BP-induced cancer cell apoptosis was detected by acridine orange/ethidium bromide staining and flow cytometry analysis, and was identified to be associated with the induction of caspase-3 and cytochrome c protein expression. Furthermore, BPs significantly decreased cancer cell migration in a dose-dependent manner and reduced matrix metallopeptidase-9 protein expression. In summary, the current study demonstrated that BPs exhibited a direct anticancer effect and an antimigratory effect on MCF-7 cells. These findings suggest that BPs may be developed as a therapeutic option for breast cancer and may serve as sensitizing chemotherapeutic agents.

The prognosis and management of neuroendocrine neoplasms-related metastatic bone disease: lessons from clinical practice

PURPOSE

To study the evolution and optimal management of metastatic bone disease (mBD) in patients with neuroendocrine neoplasms (NENs).

METHODS

Seventy-four patients were recruited from four NEN centers in this observational multicenter study.

RESULTS

Pancreas and small bowel were the most common primaries (30 and 27%, respectively). Almost all gastrointestinal (GI)-NENs were grades 1 and 2, whereas bronchopulmonary-thymic were atypical carcinoids. Thirty-two (43%) patients had synchronous metastatic bone disease (mBD) and three patients reported bone-specific symptoms; metachronous mBD developed at a median of 35 (range: 4-395) months. Thirty-six (86%) of patients with metachronous mBD had stage IV disease at diagnosis. Somatostatin receptor functional imaging and computed tomography were the modalities mostly used for mBD identification. Fifty-two patients received assessable bone-related therapy (bisphosphonates, denosumab, local radiotherapy, and radionuclide treatment). Improvement in mBD was seen in 5, stable disease in 22, and deterioration in 25 patients. The presence of synchronous mBD and the negative outcome of bone-related therapy negatively affected overall survival (OS). In the multivariate analysis, the stronger predictor of OS was the outcome of bone-related therapy (HR: 4.753; 95% CI: 1.589-14.213). Bisphosphonates therapy was the mostly used bone-specific treatment but its monthly administration did not affect OS. At last follow-up, 39 patients were alive with OS 50 (14-463) months.

CONCLUSIONS

Early investigation for mBD offers a prognostic marker of patients with NENs, since synchronous mBD has a negative impact on survival. The outcome of bone-related therapy affects OS but the monthly administration of bisphosphonates did not show a benefit over less intense schemes.

Development of Zoledronic Acid-Based Nanoassemblies for Bone-Targeted Anticancer Therapy

Bone metastasis occurs in the majority of cancer patients, which hampers quality of life and significantly decreases survival. Aggressive chemotherapy is a traditional treatment regimen that induces severe systemic toxicities. Therefore, bone-directed therapies are highly warranted. We report a novel nanoparticle formulation that is composed of poly(vinylpyrrolidone) and tannic acid core nanoparticles (PVT NPs) that forms self-assembly with zoledronic acid (ZA@PVT NPs). The construction of ZA@PVT NPs was confirmed by particle size, zeta potential, transmission electron microscopy, and spectral analyses. An optimized bone-targeted ZA@PVT NPs formulation showed greater binding and internalization in in vitro with metastasis prostate and breast cancer cells. ZA@PVT NPs were able to deliver ZA more efficiently to tumor cells, which inhibited proliferation of human prostate and breast cancer cells. In addition, ZA@PVT NPs were capable of targeting mouse bones and prostate tumor microarray tissues (ex vivo) while sparing all other vital organs. More importantly, ZA@PVT NPs induce chemo sensitization to docetaxel treatment in cancer cells. Overall, the study results confirm that ZA-based, bone-targeted NPs have great potential for the treatment of bone metastasis in the near future.

Effects of denosumab on bone mineral density in Japanese women with osteoporosis treated with aromatase inhibitors for breast cancer

Adjuvant aromatase inhibitor (AI) therapy, for hormone receptor-positive breast cancer, in postmenopausal women is associated with bone loss, leading to an increased risk of fractures. Denosumab, an antibody raised against the receptor activator of nuclear factor-κB ligand, has been proven to protect against AI-induced bone loss. Hence, we aimed to determine whether denosumab is effective in postmenopausal Japanese women with osteoporosis, treated with AI. We prospectively evaluated the bone mineral density (BMD) in the lumbar spine and the bilateral femoral neck in 102 postmenopausal women with clinical hormone receptor-positive breast cancer, stages I-IIIA, during a postoperative period of 12 months. The other inclusion criteria for this study were: women that should receive AIs as adjuvant therapy and those with evidence of osteoporosis (lumbar spine or bilateral femoral neck BMD, equivalent to T-score classification of ≤ - 2.5) upon enrollment. The patients received supplemental calcium, vitamin D, and 60 mg of subcutaneous denosumab every 6 months. The BMD of the lumber spine increased by 4.9 and 6.6% at 6 and 12 months, respectively. An increase in BMD was observed at the femoral neck, bilaterally. Hypocalcemia ≥ grade 2, osteonecrosis of the jaw, and non-traumatic clinical fracture were not observed in this study. Our findings revealed that biannual treatment with denosumab is associated with a great increase of BMD in Japanese women receiving adjuvant AI therapy, irrespective of their previous history of AI therapy.

Zoledronic Acid-containing Nanoparticles With Minimum Premature Release Show Enhanced Activity Against Extraskeletal Tumor

Bisphosphonates are generally used to treat bone diseases, such as bone metastasis from cancer. There is evidence that, through the modification of the pharmacokinetics and biodistribution of bisphosphonates by formulating them into nanoparticles, they may be able to treat extraskeletal tumors. However, many previously reported bisphosphonate nanoparticle formulations show extensive premature release of bisphosphonates. Herein, using zoledronate (Zol), a third-generation bisphosphonate, we developed a new Zol nanoparticle formulation (denoted as Zol-NPs) by encapsulating anionic lipid-coated Zol-calcium nanocomplexes into poly(lactic- co-glycolic) acid nanoparticles emulsified with octadecanoic acid-hydrazone-polyethylene glycol (2000), an acid-sensitive cleavable emulsifying agent. The resultant Zol-NPs, about 180 nm in hydrodynamic diameter, show very limited premature release of Zol (i.e., <5% in 48 h in a simulated physiological condition) and enhanced cytotoxicity to both murine cancer cells and macrophages. In a mouse model with orthotopically transplanted mammary tumors, Zol-NPs significantly reduced the distribution of Zol in bones, but increased its distribution in tumors. Importantly, Zol-NPs also significantly inhibited tumor growth, whereas the equivalent dose of free Zol did not. This platform technology may be exploited to treat extraskeletal tumors with bisphosphonates.

Adjuvant denosumab in postmenopausal patients with hormone receptor-positive breast cancer (ABCSG-18): disease-free survival results from a randomised, double-blind, placebo-controlled, phase 3 trial

BACKGROUND

In postmenopausal women with hormone receptor-positive, early-stage breast cancer, treatment with adjuvant aromatase inhibitors is the standard of care, but it increases risk for osteoporosis and fractures. Results from the ABCSG-18 trial showed that use of denosumab as an adjuvant to aromatase inhibitor therapy significantly reduced clinical fractures. Disease-free survival outcomes from ABCSG-18 have not yet been reported.

METHODS

Postmenopausal patients with early, hormone receptor-positive, non-metastatic adenocarcinoma of the breast, who had completed their initial adjuvant treatment pathway (surgery, radiotherapy, or chemotherapy, or a combination) and were receiving adjuvant aromatase inhibitors, were enrolled at 58 trial centres in Austria and Sweden into this prospective, double-blind, placebo-controlled, phase 3 trial. With permuted block randomisation (block sizes 2 and 4, stratified by previous aromatase inhibitor use, total lumbar spine bone mineral density score at baseline, and type of centre), patients were assigned (1:1) to receive subcutaneous denosumab (60 mg) or matching placebo every 6 months during aromatase inhibitor therapy. The primary endpoint (previously reported) was the time to first clinical fracture after randomisation. The secondary endpoint reported here is disease-free survival (defined as time from randomisation to first evidence of local or distant metastasis, contralateral breast cancer, secondary carcinoma, or death from any cause) in the intention-to-treat population. This study is registered with EudraCT (number 2005-005275-15) and ClinicalTrials.gov (number NCT00556374), and is ongoing for long-term follow-up.

FINDINGS

Between Dec 18, 2006, and July 22, 2013, 3425 eligible patients were enrolled and randomly assigned; 1711 to the denosumab group and 1709 to the placebo group (with five others withdrawing consent). After a median follow-up of 73 months (IQR 58-95), 240 (14·0%) patients in the denosumab and 287 (16·8%) in the placebo group had disease-free survival events. Disease-free survival was significantly improved in the denosumab group versus the placebo group (hazard ratio 0·82, 95% CI 0·69-0·98, Cox p=0·0260; descriptive analysis, without controlling for multiplicity). In the denosumab group, disease-free survival was 89·2% (95% CI 87·6-90·8) at 5 years and 80·6% (78·1-83·1) at 8 years of follow-up, compared with 87·3% (85·7-89·0) at 5 years and 77·5% (74·8-80·2) and 8 years in the placebo group. No independently adjudicated cases of osteonecrosis of the jaw or confirmed atypical femoral fractures were recorded. The total number of adverse events was similar in the denosumab group (1367 [including 521 serious] adverse events) and the placebo group (1339 [515 serious]). The most common serious adverse events were osteoarthritis (62 [3·6%] of 1709 in the denosumab group vs 58 [3·4%] of 1690 in the placebo group), meniscus injury (23 [1·3%] vs 24 [1·4%]), and cataract (16 [0·9%] vs 28 [1·7%]). One (<0·1%) treatment-related death (due to pneumonia, septic kidney failure, and cardiac decompensation) occurred in the denosumab group.

INTERPRETATION

Denosumab constitutes an effective and safe adjuvant treatment for patients with postmenopausal hormone receptor-positive early breast cancer receiving aromatase inhibitor therapy.

FUNDING

Amgen.

Chain length effect in the functionalization of polyoxometalates with α,ω-alkyldiphosphonates

Varying the alkylene tethers in hybrids of polyoxometalates and α,ω-alkyldiphosphonates, even just by a single methylene group, has met with strong structural and magnetic responses.

The Impact of Zoledronic Acid and Radioactive Iodine Therapy on Morbi-Mortality of Patients with Bone Metastases of Thyroid Cancer Derived from Follicular Cells

OBJECTIVE

Bone metastases bring greater morbi-mortality to patients with differentiated thyroid carcinoma (DTC). Treatment was limited to radioactive iodine (RAI) and local approaches. Currently, bisphosphonates are included in the therapeutic arsenal. The aim of this study is to evaluate the impact of bone metastases and their treatment with zoledronic acid (ZA) and RAI therapy.

METHODS

We retrospectively review 50 DTC patients with structurally evident bone metastases followed in a tertiary cancer center from 1994 to 2018. Clinical-pathologic characteristics, skeletal related events (SRE), and therapeutic approaches were recorded.

RESULTS

Among the 50 patients analyzed, 22 underwent ZA adjuvant therapy and 28 did not. Mortality rate was 44%. Those patients presented SREs more frequently (90.9 vs. 67.9% the survival group, p = 0.05) and also had a greater number of bone lesions (40.9 vs. 10.7% had more than 6 metastatic sites, p = 0.03). The same group of patients was analyzed before and after therapy with ZA and the incidence of SRE decreased from 1.81 (0-8) before therapy to 0.29 (0-7) after therapy (p = 0.006). Comparing similar groups of 22 patients treated with ZA with 28 patients not treated, there was a trend of better overall survival (OS) in the group that received this drug (147 vs. 119 months, p = 0.06) and significantly improvement when bone metastases were RAI avid 155 (125-185) versus 120 (85-157) months, p < 0.01. Conclusion : ZA can successfully diminish the chance of having new SRE and possibly affect OS in DTC patients with bone metastases. The positive impact of RAI adjuvant treatment on OS is directly associated with RAI uptake.

Novel structures of platinum complexes bearing N‑bisphosphonates and study of their biological properties

Novel bisphosphonate platinum complexes: [Pt(isopropylamine)₂(BP)]NO₃ (BP = pamidronate and alendronate) have been synthesized and characterized. Their monomeric structure contains a bisphosphonate acting as chelate ligand through its oxygen atom donors, conferring the compound's cationic structure with a good solubility in water. The study of the compounds in solution showed high stability up to 24 h. The cytotoxicity in cancer cell lines has been assessed. We also present preliminary studies on the evaluation of the affinity towards biological targets such as DNA (both calf thymus DNA and supercoiled plasmid DNA) and hydroxyapatite where the complexes showed a low DNA interaction, but a clear affinity for hydroxyapatite comparing to their precursors.

Effect of denosumab administration on low bone mineral density (T-score -1.0 to -2.5) in postmenopausal Japanese women receiving adjuvant aromatase inhibitors for non-metastatic breast cancer

Although adjuvant aromatase inhibitor (AI) therapy is widely used in postmenopausal women with hormone receptor-positive breast cancer, it is known to be associated with bone loss and increased fracture risk. Denosumab, a fully human monoclonal antibody against the receptor activator of nuclear factor-κB ligand, has been shown to protect against AI-induced bone loss. However, the efficacy of denosumab in the treatment of AI-associated bone loss has not been prospectively evaluated in Japan. We prospectively monitored bone mineral density (BMD) of the lumbar spine and bilateral femoral necks in 100 postmenopausal women with hormone receptor-positive postoperative breast cancer of clinical stage I-IIIA in whom treatment with AI as adjuvant endocrine therapy was planned or had been ongoing. Study participants received supplemental calcium and vitamin D every day and denosumab (60 mg) subcutaneously every 6 months. At enrollment, patients were required to have evidence of low bone mass without meeting the criteria for osteoporosis. The primary endpoint was percentage change from baseline in lumbar spine BMD at month 12. At 6 and 12 months, lumbar spine BMD increased by 3.3 and 4.7%, respectively. BMD of the femoral necks also increased. Hypocalcemia of grade ≥2, osteonecrosis of the jaw, and non-traumatic clinical fracture did not occur. In conclusion, semi-annual treatment with denosumab was associated with increased BMD in Japanese women receiving adjuvant AI therapy, regardless of prior AI treatment.

Zoledronic acid in the management of mesothelioma - a feasibility study (Zol-A Trial): study protocol for a randomised controlled trial

BACKGROUND

Nitrogen containing bisphosphonates such as zoledronic acid (ZA) are known to contain certain anti-cancer properties. These have been investigated in the past in various cancers such as breast, prostate and colon. ZA in particular has shown promising results in pre-clinical studies. We propose a multicentre double-blind randomised controlled feasibility study to assess the recruitment and acceptability of ZA/placebo alongside chemotherapy in malignant pleural mesothelioma (MPM).

METHODS

Patients will be recruited for a 13-month period from October 2016 to November 2017. Eligible patients will be identified via the regional mesothelioma multidisciplinary team meeting. Those who receive chemotherapy will be randomised to receive either ZA or placebo alongside their chemotherapy. Those who decline chemotherapy will be offered to join the trial on the non-randomised open-labelled arm of the trial. Patients will receive a maximum of six cycles of ZA/placebo, at three-weekly cycles. All patients will be followed up for six months from randomisation. Semi-structured interviews to gather data on acceptability of trial procedures, tolerability of ZA and other relevant information will take place after the participants have completed their six cycles of treatment. For a better understanding about non-participation in mesothelioma trials we also aim to interview those who decline to take part in the trial.

DISCUSSION

The qualitative and quantitative data gathered in this feasibility trial will hopefully pave the way to designing a robust full phase III trial to investigate the potential synergistic effect of ZA and current standard treatment for MPM, cisplatin-pemetrexed combination chemotherapy.

TRIAL REGISTRATION

ISRCTN Registry, ISRCTN45536692 . Registered on 9 August 2016. EudraCT no. 2015-004433-26.