Toremifene improves lipid profiles in men receiving androgen-deprivation therapy for prostate cancer: interim analysis of a multicenter phase III study

Bone complications of cancer treatment

With the advancements in conventional treatment modalities such as radiation, chemotherapy, and surgery, as well as the emergence of immunotherapy, the overall cure rate for solid tumor malignancies has experienced a significant increase. However, it is unfortunate that exposure to cancer treatments can have detrimental effects on the function of osteoblasts and osteoclasts, disturbing bone metabolic homeostasis in patients, as well as causing damage to bone marrow cells and other bone tissues. Consequently, certain tumor treatment options may pose a risk for subsequent bone diseases. Common bone disorders associated with cancer treatment include osteonecrosis, bone loss, and secondary bone tumors. (1)Cancer treatment-related osteonecrosis is primarily linked to the use of radiation therapy and certain chemicals, such as bisphosphonates, denosumab, antiangiogenic agents, and immunomodulators. It has been observed that high-dose radiation therapy is more likely to result in osteonecrosis. (2)Chemicals and hormones, particularly sex hormones, glucocorticoids, and thyroid hormones or thyrotropic hormones, are among the factors that can contribute to cancer treatment-related bone loss. (3)Secondary bone tumors differ from metastases originating from primary tumors, and radiotherapy plays a significant role in their development, while chemotherapy may also exert some influence. Radiogenic secondary bone tumors are predominantly malignant, with osteosarcoma being the most common type. Chemotherapy may be a risk factor for the relatively rare occurrence of secondary Ewing sarcoma of the bone. These treatment-related bone disorders have a considerable adverse impact on the prognosis of cancer patients. Hence, it is imperative to prioritize the bone health of patients undergoing cancer treatment and give it further attention.

The adverse effect of anticancer drug toremifene on vascular smooth muscle cells is an important aspect of its tumor growth inhibition

PURPOSE

Toremifene (TOR) is widely used as an antineoplastic drug and has an inhibitory effect on angiogenesis in mesenteric desmoid tumors and vascular intracranial solitary fibrous tumors. However, no study has investigated the direct effect of TOR on vascular cells. This study aimed at exploring the effect of TOR on the behaviors of vascular smooth muscle cells (VSMCs).

METHODS

Human aortic umbilical vascular smooth muscle cells (HAVSMCs) were treated by TOR. Cell morphology, migration, adhesion, and proliferation assay were investigated. The cell cycle, apoptosis, mitochondrial membrane potential, and reactive oxygen species were assessed using flow cytometry. Caspase-3 and 9 activities were assayed using Caspase-3 and Caspase-9 Activity Assay kits, respectively. Immunofluorescence and Western blot assays were carried out to characterize protein expressions of PCNA, p53, and Rho/ROCK signaling pathway.

RESULTS

TOR damaged cytoskeleton, inhibited VSMC proliferation, migration, and adhesion, and induced abnormal cell morphology and apoptosis. The antiproliferative activity of TOR was associated with the induction of G0/G1 phase arrest, blocking the cell cycle. TOR disrupted intracellular reactive oxygen species and mitochondrial membrane potential, and enhanced p53 expression and the activities of caspase-3 and caspase-9. Thus, TOR-induced apoptosis by the mitochondrial signaling pathway. Additionally, TOR induced decreased Rho, ROCK, MLC, and pMLC proteins. Collectively, TOR may affect multiple behaviors of VSMCs by damaging cytoskeleton through the Rho/ROCK pathway.

CONCLUSION

The adverse effect of TOR on VSMCs could be considered as an important aspect of tumor growth inhibition.

Canadian Urological Association guideline on androgen deprivation therapy: Adverse events and management strategies

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Protocol for a phase III RCT and economic analysis of two exercise delivery methods in men with PC on ADT

BACKGROUND

Androgen deprivation therapy (ADT) is commonly used to treat prostate cancer. However, side effects of ADT often lead to reduced quality of life and physical function. Existing evidence demonstrates that exercise can ameliorate multiple treatment-related side effects for men on ADT, yet adherence rates are often low. The method of exercise delivery (e.g., supervised group in-centre vs. individual home-based) may be important from clinical and economic perspectives; however, few studies have compared different delivery models. Additionally, long-term exercise adherence and an understanding of predictors of adherence are critical to achieving sustained benefits, but such data are lacking. The primary aim of this multi-centre phase III non-inferiority randomized controlled trial is to determine whether a home-based delivery model is non-inferior to a group-based delivery model in terms of benefits in fatigue and fitness in this population. Two other key aims include examining cost-effectiveness and long-term adherence.

METHODS

Men diagnosed with prostate cancer of any stage, starting or continuing on ADT for at least 6 months, fluent in English, and living close to a study centre are eligible. Participants complete five assessments over 12 months (baseline and every 3 months during the 6-month intervention and 6-month follow-up phases), including a fitness assessment and self-report questionnaires. Biological outcomes are collected at baseline, 6, and 12 months. A total of 200 participants will be randomized in a 1:1 fashion to supervised group training or home-based training supported by smartphones, health coaches, and Fitbit technology. Participants are asked to complete 4 to 5 exercise sessions per week, incorporating aerobic, resistance and flexibility training. Outcomes include fatigue, quality of life, fitness measures, body composition, biological outcomes, and program adherence. Cost information will be obtained using patient diary-based self-report and utilities via the EQ-5D.

DISCUSSION

To disseminate publicly funded exercise programs widely, clinical efficacy and cost-effectiveness have to be demonstrated. The goals of this trial are to provide these data along with an increased understanding of adherence to exercise among men with prostate cancer receiving ADT.

TRIAL REGISTRATION

The trial has been registered at clinicaltrials.gov (Registration # NCT02834416 ). Registration date was June 2, 2016.

Estrogen and Androgen Blockade for Advanced Prostate Cancer in the Era of Precision Medicine

Androgen deprivation therapy (ADT) has been widely prescribed for patients with advanced prostate cancer (PC) to control key signaling pathways via androgen receptor (AR) and AR-collaborative transcriptional factors; however, PC gradually acquires a lethal phenotype and results in castration-resistant PC (CRPC) during ADT. Therefore, new therapeutic strategies are required in clinical practice. In addition, ARs; estrogen receptors (ERs; ERα and ERβ); and estrogen-related receptors (ERRs; ERRα, ERRβ, and ERRγ) have been reported to be involved in the development or regulation of PC. Recent investigations have revealed the role of associated molecules, such as KLF5, FOXO1, PDGFA, VEGF-A, WNT5A, TGFβ1, and micro-RNA 135a of PC, via ERs and ERRs. Selective ER modulators (SERMs) have been developed. Recently, estrogen and androgen blockade (EAB) using a combination of toremifene and ADT has been demonstrated to improve biochemical recurrence rate in treatment-naïve bone metastatic PC. In the future, the suitability of ADT alone or EAB for individuals may be evaluated by making clinical decisions on the basis of information obtained from RT-PCR, gene-panel, or liquid biopsy to create a “personalized medicine” or “precision medicine”. In this review, we summarize ER and ERR signaling pathways, molecular diagnosis, and SERMs as candidates for advanced PC treatment.

Estrogen receptor signaling in prostate cancer: Implications for carcinogenesis and tumor progression

BACKGROUND

The androgen receptor (AR) is the classical target for prostate cancer prevention and treatment, but more recently estrogens and their receptors have also been implicated in prostate cancer development and tumor progression.

METHODS

Recent experimental and clinical data were reviewed to elucidate pathogenetic mechanisms how estrogens and their receptors may affect prostate carcinogenesis and tumor progression.

RESULTS

The estrogen receptor beta (ERβ) is the most prevalent ER in the human prostate, while the estrogen receptor alpha (ERα) is restricted to basal cells of the prostatic epithelium and stromal cells. In high grade prostatic intraepithelial neoplasia (HGPIN), the ERα is up-regulated and most likely mediates carcinogenic effects of estradiol as demonstrated in animal models. The partial loss of the ERβ in HGPIN indicates that the ERβ acts as a tumor suppressor. The tumor promoting function of the TMPRSS2-ERG fusion, a major driver of prostate carcinogenesis, is triggered by the ERα and repressed by the ERβ. The ERβ is generally retained in hormone naïve and metastatic prostate cancer, but is partially lost in castration resistant disease. The progressive emergence of the ERα and ERα-regulated genes (eg, progesterone receptor (PR), PS2, TMPRSS2-ERG fusion, and NEAT1) during prostate cancer progression and hormone refractory disease suggests that these tumors can bypass the AR by using estrogens and progestins for their growth. In addition, nongenomic estrogen signaling pathways mediated by orphan receptors (eg, GPR30 and ERRα) has also been implicated in prostate cancer progression.

CONCLUSIONS

Increasing evidences demonstrate that local estrogen signaling mechanisms are required for prostate carcinogenesis and tumor progression. Despite the recent progress in this research topic, the translation of the current information into potential therapeutic applications remains highly challenging and clearly warrants further investigation.

Toremifene, a selective estrogen receptor modulator, significantly improved biochemical recurrence in bone metastatic prostate cancer: a randomized controlled phase II a trial

BACKGROUNDS

Durability of androgen-deprivation therapy (ADT) for prostate cancer (PC) is limited. Additional selective estrogen receptor modulators (SERMs) may prolong the durability of ADT, because androgen and estrogen signaling drive PC progression.

METHODS

Men with treatment-naïve bone metastatic PC were randomly assigned in 1:1:1 fashion to receive ADT, toremifene 60 mg plus ADT (TOPADT), or raloxifene 60 mg plus ADT (RAPADT). The primary endpoint was the biochemical recurrence (BCR) rate, and secondary endpoints were changes of scores of the visual analogue scale (VAS) and the functional assessment of cancer therapy (FACT).

RESULTS

A total of 15 men, 5 each, were allocated to one of the three treatment arms. The basal serum prostate-specific antigen (PSA) level was 198 ng/mL (median, range; 30-8428). Bone metastases were graded as 1 (n = 11), 2 (n = 3), and 3 (n = 1) by the extent of disease. During the median follow-up period of 1370 days (range; 431-1983), BCR occurred in 3, 0 and 2 men in ADT, TOPADT and RAPADT group, respectively. The 5-year BCR-free rate was 30, 100 and 53 %, in ADT, TOPADT and RAPADT group, respectively (p = 0.04, ADT v.s. TOPADT, p = 0.48, ADT v.s. RAPADT and p = 0.12, TOPADT v.s. RAPADT). Scores of VAS improved in all groups and remained stable throughout the study. This analysis is limited as a preliminary result in a single center.

CONCLUSIONS

Toremifene with conventional ADT significantly improved the BCR rate in treatment-naïve bone metastatic PC. Further clinical trials are warranted to confirm the promising clinical efficacy of this combination therapy.

TRIAL REGISTRATION

The protocol was registered at the University Hospital Medical Information Network ( UMIN ID;0,000,064,000 ) in Sep 25, 2011.

Management of endocrine disease: Secondary osteoporosis: pathophysiology and management

Osteoporosis is a skeletal disorder characterized by decreased mass and compromised bone strength predisposing to an increased risk of fractures. Although idiopathic osteoporosis is the most common form of osteoporosis, secondary factors may contribute to the bone loss and increased fracture risk in patients presenting with fragility fractures or osteoporosis. Several medical conditions and medications significantly increase the risk for bone loss and skeletal fragility. This review focuses on some of the common causes of osteoporosis, addressing the underlying mechanisms, diagnostic approach and treatment of low bone mass in the presence of these conditions.

Cardiovascular risk with androgen deprivation therapy for prostate cancer: potential mechanisms

Androgen deprivation therapy (ADT) is frequently used for the treatment of advanced prostate cancer. ADT is associated with numerous side effects related to its mode of action, namely the suppression of testosterone to castrate levels. Recently, several large retrospective studies have also reported an increased risk of diabetes and cardiovascular disease in men receiving ADT, although these risks have not been confirmed by prospective randomized trials. We review the literature to consider the risk of cardiovascular disease with different forms of ADT and examine in detail potential mechanisms by which any such risk could be mediated. Mechanisms discussed include the metabolic syndrome resulting from low testosterone level and the potential roles of testosterone flare, gonadotropin-releasing hormone receptors outside the pituitary gland, and altered levels of follicle-stimulating hormone. Finally, the clinical implications for men prescribed ADT for the treatment of advanced prostate cancer are considered.

The use of dietary supplements to alleviate androgen deprivation therapy side effects during prostate cancer treatment

Prostate cancer (PCa), the most commonly diagnosed cancer and second leading cause of male cancer death in Western societies, is typically androgen-dependent, a characteristic that underlies the rationale of androgen deprivation therapy (ADT). Approximately 90% of patients initially respond to ADT strategies, however many experience side effects including hot flashes, cardiotoxicity, metabolic and musculoskeletal alterations. This review summarizes pre-clinical and clinical studies investigating the ability of dietary supplements to alleviate adverse effects arising from ADT. In particular, we focus on herbal compounds, phytoestrogens, selenium (Se), fatty acids (FA), calcium, and Vitamins D and E. Indeed, there is some evidence that calcium and Vitamin D can prevent the development of osteoporosis during ADT. On the other hand, caution should be taken with the antioxidants Se and Vitamin E until the basis underlying their respective association with type 2 diabetes mellitus and PCa tumor development has been clarified. However, many other promising supplements have not yet been subjected large-scale clinical trials making it difficult to assess their efficacy. Given the demographic trend of increased PCa diagnoses and dependence on ADT as a major therapeutic strategy, further studies are required to objectively evaluate these supplements as adjuvant for PCa patients receiving ADT.

Androgen deprivation therapy for prostate cancer: long-term safety and patient outcomes

Androgen deprivation therapy (ADT) constitutes the first-line treatment for patients with locally advanced tumors, recurrent or metastatic disease. Given its widespread use, clinicians should be familiar with common side effects of this treatment. This review focuses on common side effects of ADT and available treatment options to control the side effects. Also, it briefly compares continuous ADT with other therapeutic approaches for androgen deprivation in prostate cancer patients. Similar to hormonal medications, newer non-hormonal therapeutic options including gabapentin and acupuncture have at best moderate effect in controlling hot flashes in patients on ADT. Supervised and/or home exercise programs significantly improve ADT-related fatigue, metabolic/cardiovascular side effects, and cognitive dysfunction. Denosumab, a human monoclonal antibody against RANK-L, is more effective than bisphosphonates in preventing skeletal-related events in patients with metastatic or castrate-resistant prostate cancer and unlike bisphosphonates, it can also reduce the risk of vertebral fractures in men receiving ADT for non-metastatic prostate cancer. Toremifene, a selective estrogen receptor inhibitor, has dual beneficial effects on ADT-related osteoporosis and metabolic dysfunction. Metformin coupled with lifestyle modification is also a well-tolerated treatment for metabolic changes during ADT. While producing similar oncological outcomes, intermittent ADT is associated with higher quality of life in patients under ADT by improving bone health, less metabolic and hematologic complications, and fewer hot flashes and sexual dysfunction events.

Selective estrogen receptor modulators for BPH: new factors on the ground

As the current management of BPH/lower urinary tract symptoms by traditionally involved pharmacological agents such as 5alpha-reductase inhibitors and α1-adrenoceptor antagonists is suboptimal, there is definite need of new therapeutic strategies. There is ample evidence in literature that suggests the role of estrogens in BPH development and management through the different tissue and cell-specific receptors. This article reviews the beneficial actions of selective estrogen receptor modulator (SERM) and ERβ-selective ligands, which have been demonstrated through in vitro studies using human prostate cell lines and in vivo animal studies. SERMs have anti-proliferative, anti-inflammatory and pro-apoptotic mechanisms in BPH, and also act by inhibiting various growth factors, and thus represent a unique and novel approach in BPH management directed at estrogen receptors or estrogen metabolism.

Metabolic complications of androgen deprivation therapy for prostate cancer

PURPOSE

Androgen deprivation therapy has a variety of well recognized adverse effects including vasomotor flushing, loss of libido, fatigue, gynecomastia, anemia and osteoporosis. This review focuses on the more recently described metabolic complications of androgen deprivation therapy including obesity, insulin resistance and lipid alterations as well as the association of androgen deprivation therapy with diabetes and cardiovascular disease.

MATERIALS AND METHODS

We reviewed the medical literature using the PubMed® search terms prostate cancer, androgen deprivation therapy, gonadotropin-releasing hormone agonists, obesity, insulin resistance, lipids, diabetes, cardiovascular disease and myocardial infarction. We provide a focused review and our perspective on the relevant literature.

RESULTS

Androgen deprivation therapy decreases lean mass and increases fat mass. It also decreases insulin sensitivity while increasing low density lipoprotein cholesterol, high density lipoprotein cholesterol and triglycerides. Consistent with these adverse metabolic effects, androgen deprivation therapy may be associated with a greater incidence of diabetes and cardiovascular disease. Some of these androgen deprivation therapy related metabolic changes (obesity, insulin resistance and increased triglycerides) overlap with features of the metabolic syndrome. However, in contrast to the metabolic syndrome, androgen deprivation therapy increases subcutaneous fat and high density lipoprotein cholesterol.

CONCLUSIONS

Androgen deprivation therapy increases obesity, decreases insulin sensitivity and adversely alters lipid profiles. It may be associated with a greater incidence of diabetes and cardiovascular disease. The benefits of androgen deprivation therapy should be weighed against these and other potential harms. Little is known about the optimal strategy to mitigate the adverse metabolic effects of androgen deprivation therapy. Thus, we recommend an emphasis on existing strategies for screening and treatment that have been documented to reduce the risk of diabetes and cardiovascular disease in the general population.

Androgen deprivation therapy toxicity and management for men receiving radiation therapy

Androgen deprivation therapy is commonly used in combination with radiotherapy as part of the definitive treatment for men with clinically localized and locally advanced prostate cancer. Androgen deprivation has been associated with a wide range of iatrogenic effects impacting a variety of body systems including metabolic, musculoskeletal, cardiovascular, neurocognitive, and sexual. This review aims to provide the radiation oncology community with the knowledge to monitor and manage androgen deprivation therapy toxicity in an effort to provide the highest level of care for patients and to minimize the iatrogenic effects of androgen deprivation as much as possible.

The cardiovascular risk of gonadotropin releasing hormone agonists in men with prostate cancer: an unresolved controversy

Gonadotropin-releasing hormone agonists (GnRH) play an important role in the treatment of prostate cancer, improving significantly overall survival. GnRH agonists belong to androgen deprivation therapy (ADT) together with surgical castration and, recently, GnRH antagonists. ADT has several side effects, such as sexual dysfunction and osteoporosis. Recently, changes in body composition, obesity, insulin resistance, hyperglycemia, dyslipidemia, and hypertension have emerged as complications of ADT, perhaps responsible for cardiovascular events, but discussion is still open. Since the majority of men with prostate cancer die of conditions other than their malignancy, recognition of these adverse effects is important. This review serves to focus attention on the pathogenetic mechanisms of ADT-related cardiovascular toxicity with also reference to the possible direct role of GnRH agonist on the cardiac receptors. Furthermore, this paper would generate recommendations for the management of patients treated with GnRH agonists balancing the potential benefits against the possible risks in prostate cancer men.

Fasting blood glucose and lipid profile alterations following twelve-month androgen deprivation therapy in men with prostate cancer

PURPOSE

In this retrospective study, we aimed to investigate the effects of androgen deprivation therapy (ADT) on blood glucose and blood cholesterol levels over a 12-month period.

MATERIALS AND METHODS

Between January 2010 and June 2012, the data of 44 patients with prostate cancer who were receiving ADT were collected from a hospital database. Patients with additional malignancy or diabetes and those who had been prescribed and were currently taking cholesterol-lowering medication were excluded from the study. Data (including fasting blood glucose levels and a cholesterol profile) were collected and analysed statistically. A P value <0.05 was considered statistically significant.

RESULTS

Twelve months after the initiation of ADT, fasting blood glucose (FBG), total cholesterol (TC), low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol, and triglyceride (TG) levels changed. FBG, TC, LDL cholesterol, and TG increased significantly (P = 0.009, 0.000, 0.000, and 0.000, resp.), while HDL cholesterol decreased (P = 0.000).

CONCLUSION

ADT may increase FBG, TC, LDL cholesterol, and TG but decrease HDL cholesterol by the end of a year of treatment. Therefore, close followup may be needed as a consequence of one-year ADT regarding metabolic alterations.

Preclinical characterization of a novel diphenyl benzamide selective ERα agonist for hormone therapy in prostate cancer

Androgen deprivation therapy (ADT) is the mainstay of treatment for advanced prostate cancer. ADT improves overall and disease-free survival rates, but long-term therapy is associated with severe side effects of androgen and estrogen depletion including hot flashes, weight gain, depression, and osteoporosis. Effective hormone reduction can be achieved without estrogen deficiency-related side effects by using therapy with estrogenic compounds. However, cardiovascular complications induced by estrogens coupled with the availability of LHRH agonists led to discontinuation of estrogen use for primary androgen deprivation therapy in the 1980s. New treatments for prostate cancer that improve patient outcomes without the serious estrogen deficiency-related toxicities associated with ADT using LHRH analogs are needed. Herein we describe a novel nonsteroidal selective estrogen receptor-α agonist designed for first-line therapy of advanced prostate cancer that in animal models induces medical castration and minimizes many of the estrogen deficiency-related side effects of ADT. The present studies show that orally administered GTx-758 reversibly suppressed testosterone to castrate levels and subsequently reduced prostate volume and circulating prostate-specific antigen in relevant preclinical models without inducing hot flashes, bone loss, thrombophilia, hypercoagulation, or increasing fat mass.

Pharmacokinetic evaluation of toremifene and its clinical implications for the treatment of osteoporosis

INTRODUCTION

Toremifene is a triphenylethylene selective estrogen receptor modulator (SERM) that differs from tamoxifen in a single chloride ion addition on a side chain, resulting in a potentially more favorable toxicity profile.

AREAS COVERED

This article reviews the pharmacokinetics of toremifene and its potential use for the treatment of osteoporosis. This article was based on articles found through a literature search containing the terms 'toremifene' and 'SERMs.'

EXPERT OPINION

Toremifene can be administered orally with an excellent bioavailability. The overall pharmacokinetic profile is remarkably similar to tamoxifen. Toremifene is highly metabolized in the liver and is eliminated primarily in the feces following enterohepatic circulation. Some of its metabolites retain biological activity. This SERM was approved by the FDA for the treatment of estrogen receptor-positive metastatic breast cancer and is under investigation for its potential skeletal benefits in men on androgen deprivation therapy. Despite the positive preclinical and clinical evidences for the prevention of bone loss and fractures, the chemopreventive effect on prostate cancer remains to be confirmed and an increased risk of venous thromboembolism was evidenced in a large Phase III trial. Thus, additional data are required to establish the full clinical profile of this compound and its potential advantages over antiresorptive agents commonly in use for the treatment of osteoporosis.

Efficacy and safety of gonadotropin-releasing hormone agonists used in the treatment of prostate cancer

Androgen deprivation therapy (ADT) is the most effective systemic treatment for prostate cancer. ADT has been shown to have a high rate of response and to improve overall survival in patients with metastatic prostate cancer. In addition, multiple studies have shown that adding ADT to external beam radiation therapy leads to improvement in cure rates and overall survival in prostate cancer patients. The most commonly used ADT is gonadotropin-releasing hormone (GnRH) agonist therapy. Although GnRH agonist therapy has significant benefits for patients with prostate cancer, it has also been shown to have significant side effects, including fatigue, hot flashes, decreased libido, decreased quality of life, obesity, diabetes mellitus, coronary artery disease, decreased bone mineral density, and increased risk of fractures. Therefore, it is crucial that the benefits of ADT be weighed against its potential adverse effects before its use.

Cardiotoxicity of molecularly targeted agents

Cardiac toxicity of molecularly targeted cancer agents is increasingly recognized as a significant side effect of chemotherapy. These new potent therapies may not only affect the survival of cancer cells, but have the potential to adversely impact normal cardiac and vascular function. Unraveling the mechanisms by which these therapies affect the heart and vasculature is crucial for improving drug design and finding alternative therapies to protect patients predisposed to cardiovascular disease. In this review, we summarize the classification and side effects of currently approved molecularly targeted chemotherapeutics.

A prospective, randomized pilot study evaluating the effects of metformin and lifestyle intervention on patients with prostate cancer receiving androgen deprivation therapy

Study Type - Therapy (RCT) Level of Evidence 1b What's known on the subject? and What does the study add? Men with prostate cancer have higher rates of non-cancer mortality and CV morbidity and some of that excess risk has been attributed to the treatment they receive. ADT is an established treatment option for men with locally-advanced and metastatic prostate cancer and, although it has been shown to confer a disease-free survival advantage, it has also been associated with an increased incidence of CV disease and the metabolic syndrome (characterized by a cluster of CV risk factors, including insulin resistance). The benefits of the insulin sensitizer metformin and lifestyle intervention for reducing the incidence of metabolic syndrome have been shown in patients with impaired glucose tolerance. At the time of writing, the present study is the first to use metformin and lifestyle intervention in men with prostate cancer with the aim of reducing the risk of developing ADT-related CV morbidity and the metabolic syndrome. The study shows that lifestyle changes and metformin may indeed reduce the complications of androgen suppression in these men. Although further investigations are needed to establish which of the two interventions may be most beneficial, the favourable effects of a combination of these interventions on patients' quality of life and the potential for improved overall survival are of clinical significance.

OBJECTIVE

To investigate the effects of metformin and lifestyle changes on the development of androgen deprivation therapy (ADT)-related metabolic syndrome.

PATIENTS AND METHODS

Men with prostate cancer due to receive ADT were recruited and randomized. Controls received ADT alone. Men in the intervention arm received ADT with 6 months of metformin, a low glycaemic index diet and an exercise programme. All patients were investigated pretreatment and at 6 months for the metabolic syndrome, as well as for related biochemical and physical parameters.

RESULTS

In total, 40 men were recruited and randomized (20 to each arm). After 6 months, significant improvements in abdominal girth (P= 0.05), weight (P < 0.001), body mass index (P < 0.001) and systolic blood pressure (P= 0.01) were seen in the intervention arm compared to controls. Biochemical markers of insulin resistance did not differ significantly.

CONCLUSIONS

The present study shows the potential benefits of metformin and lifestyle changes in ADT-treated men. Further studies will aim to determine which intervention is most important, and may show that overall survival can be improved.

Bone health in the prostate cancer patient receiving androgen deprivation therapy: a review of present and future management options

Osteoporosis and bone fractures are frequently overlooked complications of androgen deprivation therapy in men with nonmetastatic prostate cancer. All such patients should have their bone mineral density (BMD) monitored and be offered preventive measures, such as calcium and vitamin D supplementation; patients with low BMD should be offered treatment. Several agents, including bisphosphonates, are available (although this use is currently off-label), and upcoming treatments, such as denosumab and toremifene, have shown promise in reducing fracture risk in these patients.

Androgen deprivation therapy in prostate cancer: anticipated side-effects and their management

PURPOSE OF REVIEW

In men with metastatic or recurrent prostate cancer, androgen deprivation therapy (ADT) is the standard of care. Although effective in cancer control, ADT is associated with multiple adverse effects of which physicians and patients should be aware herein we review these side-effects and their potential management.

RECENT FINDINGS

ADT reduces serum levels of testosterone and estrogen, resulting in changes in body composition, increased fracture risk, development of insulin resistance, and an unfavorable lipid profile. A number of studies have investigated the association of ADT with cardiovascular mortality; however, it is unclear whether such an association exists. Recently, two separate clinical trials have found that denosumab, a monoclonal antibody, and toremifene citrate, a selective estrogen receptor modulator, could be used to reduce the incidence of fracture in men on ADT.

SUMMARY

By providing clinicians with a greater awareness of the literature on ADT, we may minimize the physical and psychological impact of its side-effects. Physicians should be aware of a recent statement by a multilateral advisory panel, stating that there is no indication for a cardiovascular evaluation before starting ADT. Finally, physicians should be informed of recent developments in the prevention of vertebral fractures in men on ADT.

Androgens and estrogens in benign prostatic hyperplasia: past, present and future

Benign prostatic hyperplasia (BPH) and associated lower urinary tract symptoms (LUTS) are common clinical problems in urology. While the precise molecular etiology remains unclear, sex steroids have been implicated in the development and maintenance of BPH. Sufficient data exists linking androgens and androgen receptor pathways to BPH and use of androgen reducing compounds, such as 5α-reductase inhibitors which block the conversion of testosterone into dihydrotestosterone, are a component of the standard of care for men with LUTS attributed to an enlarged prostate. However, BPH is a multifactorial disease and not all men respond well to currently available treatments, suggesting factors other than androgens are involved. Testosterone, the primary circulating androgen in men, can also be metabolized via CYP19/aromatase into the potent estrogen, estradiol-17β. The prostate is an estrogen target tissue and estrogens directly and indirectly affect growth and differentiation of prostate. The precise role of endogenous and exogenous estrogens in directly affecting prostate growth and differentiation in the context of BPH is an understudied area. Estrogens and selective estrogen receptor modulators (SERMs) have been shown to promote or inhibit prostate proliferation signifying potential roles in BPH. Recent research has demonstrated that estrogen receptor signaling pathways may be important in the development and maintenance of BPH and LUTS; however, new models are needed to genetically dissect estrogen regulated molecular mechanisms involved in BPH. More work is needed to identify estrogens and associated signaling pathways in BPH in order to target BPH with dietary and therapeutic SERMs.

Estrogen action and prostate cancer

Early work on the hormonal basis of prostate cancer focused on the role of androgens, but more recently estrogens have been implicated as potential agents in the development and progression of prostate cancer. In this article, we review the epidemiological, laboratory and clinical evidence that estrogen may play a causative role in human prostate cancer, as well as rodent and grafted in vivo models. We then review recent literature highlighting potential mechanisms by which estrogen may contribute to prostate cancer, including estrogenic imprinting and epigenetic modifications, direct genotoxicity, hyperprolactinemia, inflammation and immunologic changes, and receptor-mediated actions. We discuss the work performed so far separating the actions of the different known estrogen receptors (ERs), ERα and ERβ, as well as G-protein-coupled receptor 30 and their specific roles in prostate disease. Finally, we predict that future work in this field will involve more investigations into epigenetic changes, experiments using new models of hormonal dysregulation in developing human prostate tissue, and continued delineation of the roles of the different ER subtypes, as well as their downstream signaling pathways that may serve as therapeutic targets.

An update on the changing indications for androgen deprivation therapy for prostate cancer

Quality of life has become increasingly more important for men diagnosed with prostate cancer. In light of this and the recognized risks of androgen deprivation therapy (ADT), the guidelines and use of ADT have changed significantly over the last few years. This paper reviews the current recommendations and the future perspectives regarding ADT. The benefits of ADT are evident neoadjuvantly and adjuvantly in patients treated with external beam radiation therapy for intermediate- and high-risk disease, in patients who have undergone prostatectomy with lymph node involvement, in high-risk patients after definitive therapy, and in patients who have developed progression or metastasis. Finally, this paper reviews the risks and benefits of each of these scenarios and the risks of androgen deprivation in general, and it delineates the areas where ADT was previously recommended, but where evidence is lacking for its additional benefit.

Changes in blood glucose and cholesterol levels due to androgen deprivation therapy in men with non-metastatic prostate cancer

OBJECTIVE

To investigate the effects of androgen deprivation therapy (ADT) on blood glucose and cholesterol over 12 months in a prospective matched cohort study.

METHODS

English-speaking patients with non-metastatic prostate cancer attending the Princess Margaret Hospital were invited to participate in this study. Patients were divided into two cohorts: ADT users and controls. Androgen deprivation therapy users were frequency matched to controls on age, education and body mass index (BMI). The study consisted of two visits. Sociodemographic and clinical information, medication use, physical fitness, height and weight were collected before initiation of ADT. Twelve months later, fasting morning blood work was obtained to measure plasma glucose, total cholesterol, high-density lipoprotein (HDL), low-density lipoprotein (LDL) and triglycerides. Statistical analyses included univariate and multivariable linear regression.

RESULTS

We recruited 75 patients (mean age 68.9), 38 of whom were undergoing ADT. Twelve patients with prior diabetes and 29 patients taking cholesterol-lowering medication at baseline were excluded from the glucose and cholesterol analysis, respectively. In adjusted analyses, ADT users had a significantly higher glucose level compared to controls (5.88 vs. 5.52 mmol/L, p = 0.024). Overall, ADT users had higher levels of total cholesterol, HDL, LDL, and triglycerides than controls, although none of the differences reached statistical significance.

CONCLUSION

One year of ADT use is associated with elevated fasting glucose levels and may increase all lipid fractions in men with prostate cancer.

An update on androgen deprivation therapy for prostate cancer

Androgen deprivation therapy (ADT) with gonadal testosterone depletion is the frontline treatment for advanced prostate cancer. Other hormonal interventions have a role in the treatment of prostate cancer. We sought to examine systematically the evidence for hormonal interventions in prostate cancer, risks of ADT, and interventions that mitigate these risks. Search results for therapeutic studies were focused primarily on randomized controlled clinical trials, and the Jadad scale criteria were used to evaluate the quality of these studies. Four trials of the efficacy of intermittent ADT versus continuous ADT were included. One randomized study analysis and six postrandomization analyses were included on the effects of ADT on cardiovascular mortality. Seven randomized controlled trials of pharmacologic interventions were included for the treatment of metabolic effects due to ADT. One randomized trial of GnRH antagonist versus GnRH agonist was included. Six phase I/II clinical trials of secondary hormonal therapies with novel mechanisms of action were included. Randomized studies completed to date indicate that intermittent ADT might be equivalent to continuous ADT. Although adverse effects of ADT include risk factors for cardiovascular disease, effects on cardiovascular mortality are uncertain. Bone loss and increased risk of fracture may be effectively treated with pharmacologic interventions. Benefits of ADT must be balanced with a consideration of the risks.

Drug-induced osteoporosis: mechanisms and clinical implications

Drug-induced osteoporosis is common and has a significant impact on the prognosis of patients suffering from chronic debilitating diseases. Glucocorticoids are the drugs causing osteoporotic fractures most frequently, but osteoporosis with fractures is observed also in women treated with aromatase inhibitors for breast cancer, in men receiving anti-androgen therapy for prostate cancer, in postmenopausal women treated with high doses of thyroxine, and in men and women treated with thiazolinediones for type 2 diabetes mellitus. Bone loss with fractures also occurs in patients treated with drugs targeting the immune system, such as calcineurin inhibitors, antiretroviral drugs, selective inhibitors of serotonin reuptake, anticonvulsants, loop diuretics, heparin, oral anticoagulants, and proton pump inhibitors.

Cardiac and cognitive effects of androgen deprivation therapy: are they real?

With androgen deprivation therapy being used ever earlier and longer in the course of prostate cancer, concerns have emerged about a variety of adverse effects, including cardiovascular disease and cognitive dysfunction. Conflicting data in both areas have led to controversy and confusion. Here, we review published data in an attempt to clarify those issues.

Disruption of androgen and estrogen receptor activity in prostate cancer by a novel dietary diterpene carnosol: implications for chemoprevention

Emerging data are suggesting that estrogens, in addition to androgens, may also be contributing to the development of prostate cancer (PCa). In view of this notion, agents that target estrogens, in addition to androgens, may be a novel approach for PCa chemoprevention and treatment. Thus, the identification and development of nontoxic dietary agents capable of disrupting androgen receptor (AR) in addition to estrogen receptor (ER) could be extremely useful in the management of PCa. Through molecular modeling, we found that carnosol, a dietary diterpene, fits within the ligand-binding domain of both AR and ER-alpha. Using a time-resolved fluorescence resonance energy transfer assay, we found that carnosol interacts with both AR and ER-alpha and additional experiments confirmed that it functions as a receptor antagonist with no agonist effects. LNCaP, 22Rv1, and MCF7 cells treated with carnosol (20-40 mumol/L) showed decreased protein expression of AR and ER-alpha. Oral administration of carnosol at 30 mg/kg 5 days weekly for 28 days to 22Rv1 PCa xenografted mice suppressed tumor growth by 36% (P = 0.028) and was associated with a decrease in serum prostate-specific antigen by 26% (P = 0.0042). These properties make carnosol unique to any known antiandrogen or antiestrogen investigated thus far for the simultaneous disruption of AR and ER-alpha. We suggest that carnosol may be developed or chemically modified through more rigorous structure-activity relationship studies for a new class of investigational agents-a dual AR/ER modulator.

Managing cancer treatment-induced bone loss and osteoporosis in patients with breast or prostate cancer

PURPOSE

To discuss trends in breast and prostate cancer prevalence and survival; risk factors for bone loss, osteoporosis, and fractures and the approach to risk assessment in patients with these malignancies; established and investigational drug therapies for managing cancer treatment-induced bone loss and osteoporosis; and the role of health-system pharmacists in promoting bone health in patients with breast or prostate cancer.

SUMMARY

Breast cancer and prostate cancer are common, deadly diseases, but many survivors are alive today because of improvements in early detection and treatment over the past 10-15 years. Cancer chemotherapy, corticosteroids, hormone-ablation therapy, and other common risk factors place patients with breast or prostate cancer at high risk for bone loss, osteoporosis, and fractures. Most patients with breast or prostate cancer should undergo assessment of risk for bone loss and osteoporosis that involves a bone-related history and physical examination, dual-energy X-ray absorptiometry scanning, and the FRAX fracture risk assessment tool from the World Health Organization. A recent National Comprehensive Cancer Network task force report on bone health in cancer care provides recommendations for considering the use of pharmacologic therapy on the basis of the results of this assessment. Bisphosphonates are useful for slowing or preventing bone loss associated with hormone-ablation therapy in women with breast cancer and men with prostate cancer, although fracture data are limited in women and not available in men. The usefulness of other therapies (selective estrogen receptor modulators, teriparatide, calcitonin salmon, and estrogens) is limited by adverse effects, a lack of experience with the drugs in these patient populations, or both. Various drug therapies are in development for managing cancer treatment-induced bone loss and osteoporosis. The agent closest to approval by the Food and Drug Administration, denosumab, has been shown to improve bone mineral density in women and men receiving hormone-ablation therapy for breast or prostate cancer, but additional data are needed to dispel safety concerns that could limit the use of this drug in these patient populations. Health-system pharmacists play an important role in screening patients with a history of breast or prostate cancer for bone loss or osteoporosis, making drug therapy recommendations to address the problem, and counseling patients on modifiable risk factors for osteoporosis and proper use of drug therapies to improve bone health.

CONCLUSION

Health-system pharmacists can improve the detection and management of cancer treatment-induced bone loss and osteoporosis in patients receiving systemic therapy for breast or prostate cancer.

Breast and prostate cancer: more similar than different

Breast cancer and prostate cancer are the two most common invasive cancers in women and men, respectively. Although these cancers arise in organs that are different in terms of anatomy and physiological function both organs require gonadal steroids for their development, and tumours that arise from them are typically hormone-dependent and have remarkable underlying biological similarities. Many of the recent advances in understanding the pathophysiology of breast and prostate cancers have paved the way for new treatment strategies. In this Opinion article we discuss some key issues common to breast and prostate cancer and how new insights into these cancers could improve patient outcomes.

Pharmacology and clinical applications of selective estrogen receptor modulators

Compounds that can be described as selective estrogen receptor modulators (SERMs) have expanded dramatically over the past two decades. The ability of SERMs to act as estrogens in certain tissues while remaining inert or acting as an anti-estrogen in other tissues has opened up opportunities for treating specific estrogen-modulated diseases without accepting the risk of systemic estrogen activity. SERM development has resulted in significant therapeutic advances for breast cancer, osteoporosis and potentially other diseases associated with the menopause. After the publication of the Women's Health Initiative, interest in compound selectivity that reduces menopausal symptoms while protecting bone, breast, uterus and the heart has increased. Future SERMs may also have a therapeutic profile that can be tailored to specific patient populations, including men. This review paper summarizes the characteristics of different SERMs from various pharmacological categories and the feasibility and scope of their use for a large range of disease/health conditions.

Update on the management of prostate cancer with goserelin acetate: patient perspectives

The guidelines for the use of androgen deprivation therapy (ADT) have changed significantly over the last 5 years. This paper reviews the current recommendations and documents the reasons for these changes, in a review of the world's literature on ADT over the last 5 years. Special emphasis on randomized controlled trials and high-impact journals was included in the Medline search and review. One hundred articles on this topic written in the last 5 years were reviewed. Fifty-nine contained nonindustry-biased findings in major-impact journals and were available in English. The benefits of ADT are evident in several areas, including neoadjuvantly and adjuvantly in patients treated with external beam radiation therapy for intermediate- and high-risk disease; in patients who have undergone prostatectomy and who are found to have lymph node involvement on surgical resection; in high-risk patients after definitive therapy; and in patients who have developed symptomatic local progression or metastasis. This paper reviews the risks and benefits in each of these scenarios and the risks of androgen deprivation in general, and delineates the areas where ADT was previously recommended, but has been found to no longer be of benefit.

NCCN Task Force Report: Bone Health in Cancer Care

Bone health and maintenance of bone integrity are important components of comprehensive cancer care in both early and late stages of disease. Risk factors for osteoporosis are increased in patients with cancer, including women with chemotherapy-induced ovarian failure, those treated with aromatase inhibitors for breast cancer, men receiving androgen-deprivation therapy for prostate cancer, and patients undergoing glucocorticoid therapy. The skeleton is a common site of metastatic cancer recurrence, and skeletal-related events are the cause of significant morbidity. The National Comprehensive Cancer Network (NCCN) convened a multidisciplinary task force on Bone Health in Cancer Care to discuss the progress made in identifying effective screening and therapeutic options for management of treatment-related bone loss; understanding the factors that result in bone metastases; managing skeletal metastases; and evolving strategies to reduce bone recurrences. This report summarizes presentations made at the meeting.