Rationale for using raloxifene to prevent both osteoporosis and breast cancer in postmenopausal women

Treatment Sequence for Osteoporosis

BACKGROUND

Osteoporosis is a chronic progressive disease that requires lifelong monitoring and treatment. Sequencing from one treatment to another at different ages and stages of disease is an approach that can maximize benefits and avoid potential risks from long-term treatment with a single agent.

OBJECTIVE

This article reviews clinical trial data in postmenopausal women that evaluate the effects of antiresorptive agents followed by other antiresorptives, osteoanabolic agents followed by antiresorptives, and antiresorptives followed by osteoanabolic medications.

METHODS

Literature review and discussion.

RESULTS

When medications are discontinued, in the absence of sequential therapy, bone turnover rates return to baseline or above baseline, and bone loss occurs. The rate of bone loss differs for different treatments, with a very slow decline after stopping bisphosphonates and a particularly rapid decline after stopping denosumab. Careful attention to osteoporosis medication transitions can mitigate bone density loss and its consequences. For women who remain at high risk, switching from bisphosphonates to the more potent antiresorptive, denosumab, will result in further improvement in bone mineral density (BMD). When indicated, stopping denosumab can be accomplished safely by transition to an adequate bisphosphonate regimen. For high- and very-high-risk patients, treating with osteoanabolic agents first, followed by antiresorptive agents, produces substantially larger BMD gains than the reverse treatment sequence, with the biggest differences seen for BMD of the hip.

CONCLUSION

Awareness of the importance of treatment sequences can help improve osteoporosis care across the postmenopausal lifespan.

Bioactives and Biomaterial Construction for Modulating Osteoclast Activities

Bone tissue constitutes 15-20% of human body weight and plays a crucial role in supporting the body, coordinating movement, regulating mineral homeostasis, and hematopoiesis. The maintenance of bone homeostasis relies on a delicate balance between osteoblasts and osteoclasts. Osteoclasts, as the exclusive "bone resorbers" in the human skeletal system, are of paramount significance yet often receive inadequate attention. When osteoclast activity becomes excessive, it frequently leads to various bone metabolic disorders, subsequently resulting in secondary bone injuries, such as fractures. This not only reduces life quality of patients, but also imposes a significant economic burden on society. In response to the pressing need for biomaterials in the treatment of osteoclast dysregulation, there is a surge of research and investigations aimed at osteoclast regulation. Promising progress is achieved in this domain. This review seeks to provide a comprehensive understanding of how to modulate osteoclast activities. It summarizes bioactive substances that influence osteoclasts and elucidates strategies for constructing related biomaterial systems. It offers practical insights and ideas for the development and application of biomaterials and tissue engineering, with the hope of guiding the clinical treatment of osteoclast-related bone diseases using biomaterials in the future.

Polyphosphate kinase-1 regulates bacterial and host metabolic pathways involved in pathogenesis of Mycobacterium tuberculosis

Inorganic polyphosphate (polyP) is primarily synthesized by Polyphosphate Kinase-1 (PPK-1) and regulates numerous cellular processes, including energy metabolism, stress adaptation, drug tolerance, and microbial pathogenesis. Here, we report that polyP interacts with acyl CoA carboxylases, enzymes involved in lipid biosynthesis in Mycobacterium tuberculosis. We show that deletion of ppk-1 in M. tuberculosis results in transcriptional and metabolic reprogramming. In comparison to the parental strain, the Δppk-1 mutant strain had reduced levels of virulence-associated lipids such as PDIMs and TDM. We also observed that polyP deficiency in M. tuberculosis is associated with enhanced phagosome-lysosome fusion in infected macrophages and attenuated growth in mice. Host RNA-seq analysis revealed decreased levels of transcripts encoding for proteins involved in either type I interferon signaling or formation of foamy macrophages in the lungs of Δppk-1 mutant-infected mice relative to parental strain-infected animals. Using target-based screening and molecular docking, we have identified raloxifene hydrochloride as a broad-spectrum PPK-1 inhibitor. We show that raloxifene hydrochloride significantly enhanced the activity of isoniazid, bedaquiline, and pretomanid against M. tuberculosis in macrophages. Additionally, raloxifene inhibited the growth of M. tuberculosis in mice. This is an in-depth study that provides mechanistic insights into the regulation of mycobacterial pathogenesis by polyP deficiency.

A high-throughput drug screening identifies luteolin as a therapeutic candidate for pathological cardiac hypertrophy and heart failure

Background

Pathological cardiac hypertrophy is commonly resulted from sustained pressure overload and/or metabolic disorder and eventually leads to heart failure, lacking specific drugs in clinic. Here, we aimed to identify promising anti-hypertrophic drug(s) for heart failure and related metabolic disorders by using a luciferase reporter-based high-throughput screening.

Methods

A screen of the FDA-approved compounds based on luciferase reporter was performed, with identified luteolin as a promising anti-hypertrophic drug. We systematically examined the therapeutic efficacy of luteolin on cardiac hypertrophy and heart failure in vitro and in vivo models. Transcriptome examination was performed to probe the molecular mechanisms of luteolin.

Results

Among 2,570 compounds in the library, luteolin emerged as the most robust candidate against cardiomyocyte hypertrophy. Luteolin dose-dependently blocked phenylephrine-induced cardiomyocyte hypertrophy and showed extensive cardioprotective roles in cardiomyocytes as evidenced by transcriptomics. More importantly, gastric administration of luteolin effectively ameliorated pathological cardiac hypertrophy, fibrosis, metabolic disorder, and heart failure in mice. Cross analysis of large-scale transcriptomics and drug-target interacting investigations indicated that peroxisome proliferator activated receptor γ (PPARγ) was the direct target of luteolin in the setting of pathological cardiac hypertrophy and metabolic disorders. Luteolin can directly interact with PPARγ to inhibit its ubiquitination and subsequent proteasomal degradation. Furthermore, PPARγ inhibitor and PPARγ knockdown both prevented the protective effect of luteolin against phenylephrine-induced cardiomyocyte hypertrophy in vitro.

Conclusion

Our data clearly supported that luteolin is a promising therapeutic compound for pathological cardiac hypertrophy and heart failure by directly targeting ubiquitin-proteasomal degradation of PPARγ and the related metabolic homeostasis.

Perils of prolonged ovarian suppression and hypoestrogenism in the treatment of breast cancer: Is the risk of treatment worse than the risk of recurrence?

Premenopausal breast cancer is usually estrogen receptor positive, and hence, prolonged ovarian suppression by medical or surgical means to prevent recurrence has become standard of management to improve disease-free survival. Ten-year adjuvant tamoxifen therapy is associated with 3.5% fewer recurrences compared to five years. The SOFT trial demonstrated small but statistically significant incremental improvements in long-term disease-free survival by the addition of gonadotropin-releasing hormone analog treatment (triptorelin) to an aromatase inhibitor (exemestane). Profound hypoestrogenism in the premenopausal age group may not be well tolerated due to a host of bothersome side effects (primarily vasomotor symptoms, musculoskeletal complaints, genitourinary syndrome of menopause, and mood disorders). Prolonged hypoestrogenism in younger women is associated with premature development of cardiovascular disease, bone loss, cognitive decline, and all-cause mortality. This paper explores multi-system consequences of prolonged hypoestrogenism in premenopausal women derived from studies of women with and without breast cancer. Pretreatment counseling in estrogen receptor positive breast cancer should emphasize the benefit of prolonged estrogen suppression on breast cancer recurrence and established risks of lifelong hypoestrogenism on quality of life and all-cause mortality. Future genomic research may help identify the best candidates for extended ovarian suppression to avoid treating many women when only a minority benefit.

Pharmacologic and hormonal treatments for menopausal sleep disturbances: A network meta-analysis of 43 randomized controlled trials and 32,271 menopausal women

This network meta-analysis aimed at investigating efficacy/tolerability of pharmacologic/hormonal interventions for menopausal sleep disturbances. Major databases were searched for randomized controlled trials (RCTs) examining pharmacologic or hormonal interventions with either placebo or active controlled designs. Primary outcomes were improvements in sleep disturbance severity/tolerability (i.e., overall dropout rates), whereas secondary outcome was adverse event-related discontinuation rates. Analysis of 43 RCTs with 25 treatment arms involving 32,271 women during/after menopausal transition (age: 61.24 ± 4.23, duration: 90.83 ± 66.29 wks) showed therapeutic effect of melatonin-fluoxetine [SMD = -2.47 (95% CI:-4.19-0.74)] against sleep disturbances compared to placebo. Subgroup analysis of 15 RCTs on vasomotor symptoms demonstrated superior benefits of gabapentin [SMD = -1.04 (95% CI:-1.90-0.18)], oral combined hormone therapy [SMD = -0.62 (95% CI:-1.06-0.18)], and bazedoxifene-conjugated estrogens [SMD = -0.50 (95% CI:-0.96-0.04)] to placebo/control. Despite benefits of raloxifene-only [SMD = -1.86 (95% CI:-3.09-0.63)] and raloxifene-oral estrogen [SMD = -2.64 (95% CI:-4.64-0.63)], patient selection may be a confounder. Dropout rates were comparable between interventions and placebo/control. Eszopiclone [RR = 3.84 (95% CI: 1.14-12.87)] and oral combined hormone therapy [RR = 2.51 (95% CI: 1.04-6.07)] were associated with higher rates of adverse event-related discontinuation. The results support combined estrogen-progesterone therapy for menopausal sleep disturbances associated with vasomotor symptoms but showed no significant effects of hypnotics in this clinical setting.

Update on the Role of Neuropeptide Y and Other Related Factors in Breast Cancer and Osteoporosis

Breast cancer and osteoporosis are common diseases that affect the survival and quality of life in postmenopausal women. Women with breast cancer are more likely to develop osteoporosis than women without breast cancer due to certain factors that can affect both diseases simultaneously. For instance, estrogen and the receptor activator of nuclear factor-κB ligand (RANKL) play important roles in the occurrence and development of these two diseases. Moreover, chemotherapy and hormone therapy administered to breast cancer patients also increase the incidence of osteoporosis, and in recent years, neuropeptide Y (NPY) has also been found to impact breast cancer and osteoporosis.Y1 and Y5 receptors are highly expressed in breast cancer, and Y1 and Y2 receptors affect osteogenic response, thus potentially highlighting a potential new direction for treatment strategies. In this paper, the relationship between breast cancer and osteoporosis, the influence of NPY on both diseases, and the recent progress in the research and treatment of these diseases are reviewed.

Transfersomes: The Ultra-Deformable Carrier System for Non-Invasive Delivery of Drug

Vesicular systems have many advantages like prolonging the existence of the drug in the systemic circulation, minimizing the undesirable side-effects and helping the active moieties to reach their target sites using the carriers. However, the main drawback related to transdermal delivery is to cross stratum corneum, which can be overcome by the utilization of novel carrier systems e.g., transfersomes, which are ultra-deformable carrier systems composed of phospholipid (phosphatidylcholine) and edge activators (surfactants). Edge activators are responsible for the flexibility of the bilayer membranes of transfersomes. Different edge activators used in transfersomes include tween, span, bile salts (sodium cholate and sodium deoxycholate) and dipotassium glycyrrhizinate. These activators decrease the interfacial tension, thereby, increasing the deformability of the carrier system. Transfersomes can encapsulate both hydrophilic and hydrophobic drugs into a vesicular structure, which consists of one or more concentric bilayers. Due to the elastic nature of transfersomes, they can easily cross the natural physiological barriers i.e., skin and deliver the drug to its active site. The main benefit of using transfersomes as a carrier is the delivery of macromolecules through the skin by non-invasive route thereby increasing the patient's compliance. The transfersomal formulations can be used in the treatment of ocular diseases, alopecia, vulvovaginal candidiasis, osteoporosis, atopic dermatitis, tumor, leishmaniasis. It is also used in the delivery of growth hormones, anaesthesia, insulin, proteins, and herbal drugs. This review also focuses on the patents and clinical studies for various transfersomal products.

Investigation of Need of Natural Bioenhancer for a Metabolism Susceptible Drug-Raloxifene, in a Designed Self-Emulsifying Drug Delivery System

Bioenhancers can increase the bioavailability of metabolism susceptible drugs. The present study was designed to understand the impact of bioenhancer on permeability and bioavailability of a biopharmaceutical drug disposition classification system (BDDCS) class II drug raloxifene (RLX). RLX undergoes extensive first pass metabolism by UGT enzymes in gastrointestinal tract (GIT) and has an oral bioavailability of about 2%. Self-emulsifying drug delivery system (SEDDS) of RLX was developed using a designed approach and this formulation was loaded with reported bioenhancers: quercetin and piperine. These formulations were tested for improvement in permeability and bioavailability of the RLX. The apparent permeability using everted gut sac (P _app) for SEDDS (5.26 ± 1.10 × 10^-8 cm/s) was found to be similar to that of SEDDS with bioenhancers (5.11 ± 1.05 × 10^-8 cm/s). In oral bioavailability study in rat, SEDDS demonstrated a 4-fold and 2.5-fold higher AUC_0-∞ than RLX suspension (control) and marketed product, respectively. No additional improvement in permeability and bioavailability was offered by inclusion of piperine and quercetin (bioenhancers) in the SEDDS.

Structural features underlying raloxifene's biophysical interaction with bone matrix

Raloxifene, a selective estrogen receptor modulator (SERM), reduces fracture risk at least in part by improving the mechanical properties of bone in a cell- and estrogen receptor-independent manner. In this study, we determined that raloxifene directly interacts with the bone tissue. Through the use of multiple and complementary biophysical techniques including nuclear magnetic resonance (NMR) and Fourier transform infrared spectroscopy (FTIR), we show that raloxifene interacts specifically with the organic component or the organic/mineral composite, and not with hydroxyapatite. Structure-activity studies reveal that the basic side chain of raloxifene is an instrumental determinant in the interaction with bone. Thus, truncation of portions of the side chain reduces bone binding and also diminishes the increase in mechanical properties. Our results support a model wherein the piperidine interacts with bone matrix through electrostatic interactions with the piperidine nitrogen and through hydrophobic interactions (van der Waals) with the aliphatic groups in the side chain and the benzothiophene core. Furthermore, in silico prediction of the potential binding sites on the surface of collagen revealed the presence of a groove with sufficient space to accommodate raloxifene analogs. The hydroxyl groups on the benzothiophene nucleus, which are necessary for binding of SERMs to the estrogen receptor, are not required for binding to the bone surface, but mediate a more robust binding of the compound to the bone powder. In conclusion, we report herein a novel property of raloxifene analogs that allows them to interact with the bone tissue through potential contacts with the organic matrix and in particular collagen.

Medical treatment for adenomyosis and/or adenomyoma

Uterine adenomyosis and/or adenomyoma is characterized by the presence of heterotopic endometrial glands and stroma within the myometrium, >2.5 mm in depth in the myometrium or more than one microscopic field at 10 times magnification from the endometrium-myometrium junction, and a variable degree of adjacent myometrial hyperplasia, causing globular and cystic enlargement of the myometrium, with some cysts filled with extravasated, hemolyzed red blood cells, and siderophages. Hysterectomy is a "gold standard" and definitive therapy for uterine adenomyosis, and many cases of adenomyosis have been diagnosed by pathological review retrospectively. As such, the diagnosis of adenomyosis is difficult, and this subsequently results in difficulty in the management of these patients, especially those who are symptomatic but have a strong desire to preserve their uterus. In our previous review, we found that the use of uterine-sparing surgery in the management of uterine adenomyosis and/or adenomyoma is still controversial, although some data support its feasibility. Conservative treatment is still needed in the group of patients that requires preservation of fertility and improvement of quality of life. However, studies focusing on the topic of medical treatment for adenomyosis are rare. In this article, current knowledge regarding the use of medical therapy for uterine adenomyosis, partly based on the understanding of endometriosis, is reviewed.

Controlled release of raloxifene by nanoencapsulation: effect on in vitro antiproliferative activity of human breast cancer cells

Raloxifene hydrochloride (RH) is considered to be an antiproliferative agent of mammary tissue. The aim of this study was to investigate the effect of the encapsulation of RH in polymeric nanocapsules with anionic or cationic surface on its release profile and antiproliferative activity. They were prepared by interfacial deposition of preformed polymer, followed by wide physicochemical characterization. The in vitro RH release was assessed by the dialysis membrane method and the data analyzed by mathematical modeling. The antiproliferative effect on MCF-7 cell viability was investigated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay as well as by counting viable cells. They had high encapsulation efficiency, low polydispersity, and nanometric mean size. Nanocapsules prepared with Eudragit^® RS100 and Eudragit^® S100 presented positive and negative zeta potentials, respectively. Drug release studies demonstrated controlled release of RH from anionic nanocapsules, which could be explained due to a stronger interaction of the drug to these nanocapsules and the larger amount of entrapped drug. On the other hand, this control was not observed from cationic nanocapsules due to the larger amount of drug adsorbed onto their surface. MCF-7 cell viability studies and cell counting showed that RH-loaded Eudragit^® RS100 nanocapsules promote the best antiproliferative activity after 24 hours of treatment, whereas the best activity was observed for RH-loaded Eudragit^® S100 nanocapsules after 72 hours. Furthermore, the combined treatment of these formulations improved the antiproliferative effect during the entire treatment.

Raloxifene reduces triple-negative breast cancer tumor growth and decreases EGFR expression

The poor prognosis of patients with triple-negative breast cancer (TNBC) and the lack of targeted treatments have raised the need for alternative therapies. Previous studies have suggested an effect of raloxifene, a selective estrogen receptor modulator that is independent of the estrogen receptor (ER). Therefore, we assessed the therapeutic value of raloxifene in TNBC mouse models. Mice received a daily oral treatment with different doses of raloxifene. Tumor progression was monitored weekly; in addition microvessel density, proliferation, migration and invasion, apoptosis and tumorigenicity were analyzed. This study demonstrates that raloxifene (0.85 mg/kg) prevents TNBC tumor growth and induces tumor regression. The treated tumors showed a 54% decreased microvascular density and proliferation and a 7-fold increase in apoptosis. The underlying therapeutic mechanism of raloxifene was associated with a 27-fold decrease in the expression of the epidermal growth factor receptor (EGFR). Moreover, raloxifene promoted the translocation of EGFR into endosomes associated with decreased cell migration, cell invasion and tumorigenicity in vitro. Together, these data showed that raloxifene acts independently of the ER and may be relevant for the treatment as well as control the progression of TNBC.

Osteoporosis - a current view of pharmacological prevention and treatment

Postmenopausal osteoporosis is the most common bone disease, associated with low bone mineral density (BMD) and pathological fractures which lead to significant morbidity. It is defined clinically by a BMD of 2.5 standard deviations or more below the young female adult mean (T-score =−2.5). Osteoporosis was a huge global problem both socially and economically – in the UK alone, in 2011 £6 million per day was spent on treatment and social care of the 230,000 osteoporotic fracture patients – and therefore viable preventative and therapeutic approaches are key to managing this problem within the aging population of today. One of the main issues surrounding the potential of osteoporosis management is diagnosing patients at risk before they develop a fracture. We discuss the current and future possibilities for identifying susceptible patients, from fracture risk assessment to shape modeling and in relation to the high heritability of osteoporosis now that a plethora of genes have been associated with low BMD and osteoporotic fracture. This review highlights the current therapeutics in clinical use (including bisphosphonates, anti-RANKL [receptor activator of NF-κB ligand], intermittent low dose parathyroid hormone, and strontium ranelate) and some of those in development (anti-sclerostin antibodies and cathepsin K inhibitors). By highlighting the intimate relationship between the activities of bone forming (osteoblasts) and bone-resorbing (osteoclasts) cells, we include an overview and comparison of the molecular mechanisms exploited in each therapy.

Raloxifene attenuates Pseudomonas aeruginosa pyocyanin production and virulence

There has been growing interest in disrupting bacterial virulence mechanisms as a form of infectious disease control through the use of 'anti-infective' drugs. Pseudomonas aeruginosa is an opportunistic pathogen noted for its intrinsic antibiotic resistance that causes serious infections requiring new therapeutic options. In this study, an analysis of the P. aeruginosa PAO1 deduced proteome was performed to identify pathogen-associated proteins. A computational screening approach was then used to discover drug repurposing opportunities, i.e. identifying approved drugs that bind and potentially disrupt the pathogen-associated protein targets. The selective oestrogen receptor modulator raloxifene, a drug currently used in the prevention of osteoporosis and/or invasive breast cancer in post-menopausal women, was predicted from this screen to bind P. aeruginosa PhzB2. PhzB2 is involved in production of the blue pigment pyocyanin produced via the phenazine biosynthesis pathway. Pyocyanin is toxic to eukaryotic cells and has been shown to play a role in infection in a mouse model, making it an attractive target for anti-infective drug discovery. Raloxifene was found to strongly attenuate P. aeruginosa virulence in a Caenorhabditis elegans model of infection. Treatment of P. aeruginosa wild-type strains PAO1 and PA14 with raloxifene resulted in a dose-dependent reduction in pyocyanin production in vitro; pyocyanin production and virulence were also reduced for a phzB2 insertion mutant. These results suggest that raloxifene may be suitable for further development as a therapeutic for P. aeruginosa infection and that such already approved drugs may be computationally screened and potentially repurposed as novel anti-infective/anti-virulence agents.

Nanoemulsion liquid preconcentrates for raloxifene hydrochloride: optimization and in vivo appraisal

Raloxifene hydrochloride (RLX) is a selective estrogen-receptor modulator for treatment of osteoporosis and prevention of breast and endometrial cancer. By virtue of extensive presystemic clearance, RLX bioavailability is only 2%. The current study aimed to tailor and characterize RLX-loaded self-nanoemulsifying drug-delivery systems (SNEDDS) using bioactive excipients affecting drug metabolism. The potential of oral nanocarriers to enhance RLX delivery to endocrine target organs was assessed in fasted and fed female Wistar rats using high-performance liquid chromatography. RLX was loaded in the dissolved and dispersed status in the alkalinized (A-SNEDDS) and nonalkalinized (NA-SNEDDS) systems, respectively. Optimization and assessment relied on solubility studies, emulsification efficiency, phase diagrams, dilution robustness, cloud point, particle size, zeta potential (ZP), polydispersity index (PDI), and transmission electron microscopy. In vitro release was assessed using dialysis bag versus dissolution cup methods. NA-SNEDDS were developed with suitable globule size (38.49 ± 4.30 nm), ZP (31.70 ± 3.58 mV), PDI (0.31 ± 0.02), and cloud point (85°C). A-SNEDDS exhibited good globule size (35 ± 2.80 nm), adequate PDI (0.28 ± 0.06), and lower ZP magnitude (−21.20 ± 3.46 mV). Transmission electron microscopy revealed spherical globules and contended data of size analysis. Release studies demonstrated a nonsignificant enhancement of RLX release from NA-SNEDDS compared to drug suspension with the lowest release shown by A-SNEDDS. A conflicting result was elucidated from in vivo trial. A significant enhancement in RLX uptake by endocrine organs was observed after nanocarrier administration compared to RLX suspension. In vivo studies reflected a poor in vitro/in vivo correlation, recommended nanocarrier administration before meals, and did not reveal any advantage for drug loading in the solubilized form (A-SNEDDS). To conclude, NA-SNEDDS possessed superior in vitro characteristics to A-SNEDDS, with equal in vivo potential. NA-SNEDDS elaborated in this work could successfully double RLX delivery to endocrine target organs, with promising consequences of lower dose and side effects of the drug.

Adiponectin and leptin serum levels in osteoporotic postmenopausal women treated with raloxifene or alendronate

OBJECTIVE

Clinical studies evaluating the role of leptin and adiponectin on bone metabolism had shown conflicting results, and data about the effect of anticatabolic drugs on these adipokines are scarce. Our aims were to determine adiponectin and leptin levels in osteoporotic postmenopausal women and their relationship with bone mass and bone turnover and to analyze changes on adiponectin and leptin levels after treatment with raloxifene or alendronate.

METHODS

We selected 53 women (mean ± SD age, 63 ± 7 y) with postmenopausal osteoporosis divided into two treatment groups: raloxifene (60 mg/d; n = 20) or alendronate (70 mg/wk; n = 33) during a period of 1 year. Bone mineral density by dual-energy x-ray absorptiometry and serum levels of leptin, adiponectin, and bone turnovers markers were determined at baseline and at 1 year after treatment.

RESULTS

Baseline levels of leptin were correlated to body mass index (r = 0.47; P < 0.01), waist circumference (r = 0.38, P = 0.01), and estradiol (r = 0.4, P = 0.003). Adiponectin was inversely related to bone-specific alkaline phosphatase (r = -0.41, P < 0.01) and serum crosslaps (r = -0.35; P < 0.01). There was no correlation between bone mineral density, leptin, and adiponectin. After 12 months, no changes were observed in leptin and adiponectin in the alendronate group; however, a significant increase in leptin levels (973.5 ± 637.4 pM/mL vs 1,305.7 ± 793.5 pM/mL; P = 0.031) was detected in the raloxifene group, whereas adiponectin levels showed no significant changes (P = 0.46).

CONCLUSIONS

In postmenopausal women with osteoporosis, raloxifene induces a significant increase in leptin levels without significant changes in adiponectin serum levels. The antiresorptive effect of raloxifene and alendronate is not substantially influenced by changes in leptin or adiponectin levels.

Prospective evaluation of Vitamin K2, Raloxifene and their co-administration in osteoporotic rats

In this study, therapeutic effects of Vitamin K2, Raloxifene and their co-administration on bone, uterus, blood and weight profiles were investigated with an ovariectomized rat model. Forty Wistar rats were divided into five groups (n=8): Raloxifene (R), Vitamin K2 (K), Raloxifene+Vitamin K2 (R+K), ovariectomized controls (OVX) and Sham-operated controls (Sham). Treatment began 3 months after ovariectomy. Vitamin K2 and Raloxifene were administered 30 and 1.5 mg/kg/day separately and in combination five times per week for 12 weeks. All treatment groups had significantly higher ultimate strength and energy absorption capacity (P<0.05) than ovariectomized controls in both femur and tibia. Histological results showed that treatment groups had healthy lumen structure, whereas OVX had degeneration. Adverse effects which were seen in individual treatments (myometrium weakening in K, endometrium weakening in R, and ALP increase in group R) were not observed in the R+K group implying a synergistic effect of these two agents when they are co-administered. According to blood analysis, ALP values were significantly high in Raloxifene-only group (P<0.0001). This effect is suppressed in the co-administered group. In summary, the groups R, K and R+K had significantly higher ultimate strength and less susceptibility to fracture than ovariectomized controls. In summation, Vitamin K2 treated groups (either in single or combined with Raloxifene) had considerable biomechanical performance and reproductive tissue profile indicating that this agent is prospectively effective in osteoporosis management.

Bone health-related factors and the use of bisphosphonates in community setting--15-year follow-up study

The present study investigated the bone health related factors that were associated with the use of bisphosphonates (BP) among 2,050 postmenopausal Finnish women. Low BMD + low trauma energy fracture was the strongest determinant of BP use, while other secondary causes of osteoporosis were less strongly related with BP use. BP use was associated with reduced femoral neck (FN) and lumbar spine (LS) bone loss rate.

INTRODUCTION

The aim was to identify bone health related factors associated with the use of BP in a community setting.

METHODS

A population-based sample of 2,050 Finnish postmenopausal women was measured with dual X-ray absorptiometry at the FN and LS in 1989, 1994, 1999 and 2004, and information on osteoporosis risk factors, including low-trauma energy fractures, were collected with postal inquiries. Self-reported use of BP in 2004 was considered as the end point variable.

RESULTS

Among BP users, 12% had T-score > -2.0 SD and no fracture during follow-up (FU). In women without any bone medication, 26% had T-score < -2.0 SD or low-trauma energy fracture or both during the FU. In BP users, a significant reduction in FN and LS bone loss rate, cumulative with duration of use, was observed in ANCOVA (p < 0.001). Among BP users, there was a significantly higher proportion of women with several independent risk factors for osteoporosis and more spine and humerus fractures but less ankle fractures. T-score < -2 SD combined with low-trauma energy fracture was significantly related to the use of BPs (p < 0.001, OR = 15.96) and T-score < -2 SD was a stronger predictor of BP use (p < 0.001, OR = 13.29) than fracture (p > 0.05, OR = 1.35) in multivariate logistic regression. Other factors related with BP use were vitamin D use (p = 0.001, OR = 2.27), high number of medications (p < 0.001, OR = 1.26) and rheumatoid arthritis (p < 0.05, OR 2.55).

CONCLUSIONS

These findings reveal the recent bone health-related indications for BP prescription.

Identifying cost-effective treatment with raloxifene in postmenopausal women using risk algorithms for fractures and invasive breast cancer

INTRODUCTION

The National Osteoporosis Foundation (NOF) recommends considering treatment in women with a 20% or higher 10-year probability of a major fracture. However, raloxifene reduces both the risk of vertebral fractures and invasive breast cancer so that raloxifene treatment may be clinically appropriate and cost-effective in women who do not meet a 20% threshold risk. The aim of this study was to identify cost-effective scenarios of raloxifene treatment compared to no treatment in younger postmenopausal women at increased risk of invasive breast cancer and fracture risks below 20%.

METHOD

A micro-simulation model populated with data specific to American Caucasian women was used to quantify the costs and benefits of 5-year raloxifene treatment. The population evaluated was selected based on 10-year major fracture probability as estimated with FRAX® being below 20% and 5-year invasive breast cancer risk as estimated with the Gail risk model ranging from 1% to 5%.

RESULTS

The cost per QALY gained ranged from US $22,000 in women age 55 with 5% invasive breast cancer risk and 15-19.9% fracture probability, to $110,000 in women age 55 with 1% invasive breast cancer risk and 5-9.9% fracture probability. Raloxifene was progressively cost-effective with increasing fracture risk and invasive breast cancer risk for a given age cohort. At lower fracture risk in combination with lower invasive breast cancer risk or when no preventive raloxifene effect on invasive breast cancer was assumed, the cost-effectiveness of raloxifene worsened markedly and was not cost-effective given a willingness-to-pay of US $50,000. At fracture risk of 15-19.9% raloxifene was cost-effective also in women at lower invasive breast cancer risk.

CONCLUSIONS

Raloxifene is potentially cost-effective in cohorts of young postmenopausal women, who do not meet the suggested NOF 10-year fracture risk threshold. The cost-effectiveness is contingent on their 5-year invasive breast cancer risk. The result highlights the importance of considering a woman's full risk profile when considering anti-osteoporosis treatment.

Chronic liver disease and osteoporosis

Hepatic osteodystrophy, manifesting mainly as osteoporosis, can occur in patients with chronic liver disease (CLD) or after liver transplantation and lead to vertebral compression fracture, radial or femoral fracture. Currently, the pathogenesis of hepatic osteodystrophy is still not completely clear. The reported incidence of osteoporosis in CLD patients ranged from 12% to 55%. For CLD patients, attention should be paid to monitor osteoporosis by measuring bone mineral density on the basis of controlling liver disease to choose safe and effective medication to improve their quality of life.

Emerging drugs for the management of cancer treatment induced bone loss

AREAS COVERED IN THIS REVIEW

We focus our attention on data on the efficacy of currently available and emerging drugs for the management of cancer treatment induced bone loss (CTIBL) found in a PubMed research from 1997 till today.

IMPORTANCE OF THE FIELD

One of the most common and severe safety issues of the antihormonal therapy in both sexes is the CTIBL and the related fragility fractures. In postmenopausal women with estrogenic receptor positive breast cancer, the third-generation aromatase inhibitors (AIs) are the standard therapy. Observational retrospective studies have found that AIs treated patients had a high rate of bone loss and fracture risk (RR 1.3). Also in men with prostate cancer receiving androgen deprivation therapy, the increase in bone turnover and the consequent bone loss are very rapid and sustained significantly increasing the fracture risk.

WHAT THE READER WILL GAIN

The aim of our review is to provide the current evidences for the management of bone loss and fracture risk in this subpopulation.

TAKE HOME MESSAGE

The very high rate of bone loss and the high incidence of fractures indicate that cancer patients at risk of CTIBL need to be carefully monitored and stratified for fracture risk. Although there is a strong evidence of efficacy in prevention of bone loss and reduction of fracture risk for many drugs approved for postmenopausal osteoporosis (PMO) and male osteoporosis, for CTIBL there are actually no drugs approved for this indication.

Long-term safety and efficacy of raloxifene in the prevention and treatment of postmenopausal osteoporosis: an update

The integrity of bone tissue and its remodeling that occurs throughout life requires a coordinated activity of osteoblasts and osteoclasts. The decreased estrogen circulating level during postmenopausal transition, with a prevalence of osteoclastic activity over osteoblastic activity, represents the main cause of bone loss and osteoporosis. Osteoporosis is a chronic disease requiring long-term therapy and it is important to evaluate the efficacy and safety of treatments over several years, as the fear of health risks is a common reason for discontinuing therapy. Raloxifene is a selective estrogen receptor modulator (SERM) leading to estrogen-agonist effects in some tissues and estrogen-antagonist effects in others. Raloxifene is effective to prevent and treat postmenopausal vertebral osteoporosis, with reduction of spine fractures and, in post-hoc analyses, non-spine fractures in high-risk subjects. Moreover, raloxifene reduces the risk of invasive breast cancer and improves the levels of serum lipoprotein but with an increased risk of venous thromboembolism and fatal stroke, without significant change in the incidence of coronary events. For these reasons the overall risk-benefit profile is favorable. Therefore, when considering the use of raloxifene in a postmenopausal woman, we should take into account the osteoporosis-related individual risk and weigh the potential benefits, skeletal and extra-skeletal, against the health risks.

Antagonism of estrogen-mediated cell proliferation by raloxifene in prevention of ageing-related prostatic hyperplasia

Estrogen has important roles in the initiation and development of benign prostatic hyperplasia (BPH). Regulators of the estrogen receptor (ER) are tissue- and cell-specific. We evaluated the effect of estrogen antagonist, raloxifene (Ral), on the prevention and treatment of BPH by investigating its effect on the proliferation of two different prostate cell lines: a stromal cell line, WPMY-1, and a benign prostatic hyperplasia epithelial cell line, BPH-1. We additionally evaluated its effect on prostatic hyperplasia induced by estrogen and androgen in a rat model. The effect of Ral on the prevention of prostatic hyperplasia was analyzed by haematoxylin and eosin staining and quantitative immunohistochemistry (IHC) for proliferating cell nuclear antigen and alpha-smooth muscle actin. In vitro and in vivo, tamoxifen (Tam), another anti-estrogen drug, and finasteride (Fin), a drug for the clinical treatment of BPH, served as efficacy controls. The in vitro data showed that neither Ral nor Tam alone affected the proliferation of WPMY-1 and BPH-1, but both antagonized the effect of oestradiol in promoting the proliferation of the two cells. Results from the IHC staining of the rat prostates indicated that, similar to Tam and Fin, Ral inhibited the proliferation of stromal cells in vivo. Interestingly, in contrast to Tam, both Ral and Fin inhibited the proliferation of epithelial cells. Furthermore, Ral treatment much strongly decreased the number of prostatic acini and the surrounding layers of smooth muscle cells than Fin (P < 0.05). Our data showed for the first time that Ral may have a role in the response of the rat prostate to selective ER modulators.

Raloxifene: a review of its use in the prevention of invasive breast cancer

Raloxifene (Evista) is a second-generation selective estrogen receptor modulator (SERM) that functions as an estrogen antagonist on breast and uterine tissues, and an estrogen agonist on bone. It is available in many countries worldwide for the treatment and prevention of osteoporosis in postmenopausal women, and has also been approved in the US for reducing the risk of invasive breast cancer in postmenopausal women with osteoporosis or postmenopausal women at increased risk of invasive breast cancer.Raloxifene reduces the risk of invasive breast cancer in postmenopausal women at high risk of invasive breast cancer and in postmenopausal women with osteoporosis. In addition, it is a well established agent for the prevention and treatment of osteoporosis. There was no significant difference between raloxifene and tamoxifen in the reduction in the risk of invasive breast cancer achieved in postmenopausal women at high risk of such cancer. Raloxifene was associated with an increased, albeit rare, risk of venous thromboembolism across several placebo-controlled trials and an increased risk of fatal stroke in one placebo-controlled trial in postmenopausal woman at increased risk for major coronary events. However, raloxifene was associated with a lower risk of venous thromboembolic events and cataracts than tamoxifen in a head-to-head trial. The choice of chemoprevention agent must consider a risk-benefit assessment for each individual patient. In this context, raloxifene is a valuable option for the prevention of invasive breast cancer in postmenopausal women with osteoporosis or at high risk of invasive breast cancer.