Neridronate prevents bone loss in patients receiving androgen deprivation therapy for prostate cancer

Pharmacotherapy for Spine-Related Pain in Older Adults

As the population ages, spine-related pain is increasingly common in older adults. While medications play an important role in pain management, their use has limitations in geriatric patients due to reduced liver and renal function, comorbid medical problems, and polypharmacy. This review will assess the evidence basis for medications used for spine-related pain in older adults, with a focus on drug metabolism and adverse drug reactions. A PubMed/OVID search crossing common spine, neck, and back pain terms with key words for older adults and geriatrics was combined with common drug classes and common drug names and limited to clinical trials and age over 65 years. The results were then reviewed with identification of commonly used drugs and drug categories: nonsteroidal anti-inflammatories (NSAIDs), acetaminophen, corticosteroids, gabapentin and pregabalin, antispastic and antispasmodic muscle relaxants, tricyclic antidepressants (TCAs), serotonin-norepinephrine reuptake inhibitors (SNRIs), tramadol, and opioids. Collectively, 138 double-blind, placebo-controlled trials were the focus of the review. The review found a variable contribution of high-quality studies examining the efficacy of medications for spine pain primarily in the geriatric population. There was strong evidence for NSAID use with adjustments for gastrointestinal and renal risk factors. Gabapentin and pregabalin had mixed evidence for neuropathic pain. SNRIs had good evidence for neuropathic pain and a more favorable safety profile than TCAs. Tramadol had some evidence in older patients, but more so in persons aged < 65 years. Rational therapeutic choices based on geriatric spine pain diagnosis are helpful, such as NSAIDs and acetaminophen for arthritic and myofascial-based pain, gabapentinoids or duloxetine for neuropathic and radicular pain, antispastic agents for myofascial-based pain, and combination therapy for mixed etiologies. Tramadol can be well tolerated in older patients, but has risks of cognitive and classic opioid side effects. Otherwise, opioids are typically avoided in the treatment of spine-related pain in older adults due to their morbidity and mortality risk and are reserved for refractory severe pain. Whenever possible, beneficial geriatric spine pain pharmacotherapy should employ the lowest therapeutic doses with consideration of polypharmacy, potentially decreased renal and hepatic metabolism, and co-morbid medical disorders.

The Rationale for Using Neridronate in Musculoskeletal Disorders: From Metabolic Bone Diseases to Musculoskeletal Pain

Neridronate or ((6-amino-1-hydroxy-1-phosphonohexyl) phosphonic acid) is an amino-bisphosphonate (BP) synthetized in Italy in 1986. Bisphosphonates are molecules with a P-C-P bond in their structure that allows strong and selectively binding to hydroxyapatite (HAP) as well as osteoclasts inhibition through different mechanisms of action. Neridronate was initially used to treat Paget disease of the bone, demonstrating effectiveness in reducing bone turnover markers as well as pain. The interesting molecular properties of neridronate foster its wide use in several other conditions, such as osteogenesis imperfecta, and osteoporosis. Thanks to the unique safety and efficacy profile, neridronate has been used in secondary osteoporosis due to genetic, rheumatic, and oncological diseases, including in pediatric patients. In the last decade, this drug has also been studied in chronic musculoskeletal pain conditions, such as algodystrophy, demonstrating effectiveness in improving extraskeletal outcomes. This review highlights historical and clinical insights about the use of neridronate for metabolic bone disorders and musculoskeletal pain conditions.

Testosterone and Bone Health in Men: A Narrative Review

Bone fracture due to osteoporosis is an important issue in decreasing the quality of life for elderly men in the current aging society. Thus, osteoporosis and bone fracture prevention is a clinical concern for many clinicians. Moreover, testosterone has an important role in maintaining bone mineral density (BMD) among men. Some testosterone molecular mechanisms on bone metabolism have been currently established by many experimental data. Concurrent with a decrease in testosterone with age, various clinical symptoms and signs associated with testosterone decline, including decreased BMD, are known to occur in elderly men. However, the relationship between testosterone levels and osteoporosis development has been conflicting in human epidemiological studies. Thus, testosterone replacement therapy (TRT) is a useful tool for managing clinical symptoms caused by hypogonadism. Many recent studies support the benefit of TRT on BMD, especially in hypogonadal men with osteopenia and osteoporosis, although a few studies failed to demonstrate its effects. However, no evidence supporting the hypothesis that TRT can prevent the incidence of bone fracture exists. Currently, TRT should be considered as one of the treatment options to improve hypogonadal symptoms and BMD simultaneously in symptomatic hypogonadal men with osteopenia.

French recommendations for osteoporosis prevention and treatment in patients with prostate cancer treated by androgen deprivation

Androgen-deprivation therapy (ADT) in patients with prostate cancer can be achieved surgically or chemically, notably by prescribing LHRH analogs. Major bone loss occurs rapidly in both cases, due to the decrease in testosterone levels, and can increase the fracture risk. The objective of developing these recommendations was to achieve a practical consensus among various scientific societies, based on a literature review, about osteoporosis prevention and treatment in patients on ADT. The following scientific societies contributed to the work: Société française de rhumatologie (SFR), Groupe de recherche et d'information sur les ostéoporoses (GRIO), Groupe européen d'études des métastases osseuses (GEMO), Association francophone pour les soins de support (AFSOS), Association française d'urologie (AFU), Société française de radiothérapie oncologique (SFRO). Medication prescription and reimbursement modalities in France were taken into account. The recommendations state that a fracture-risk evaluation and interventions targeting risk factors for fractures should be provided to all patients on ADT. Those patients with a history of severe osteoporotic fracture and/or a T-score < -2.5 should receive osteoporosis therapy. Patients whose T-score is between -1.5 and -2.5 should be treated if they exhibit at least two other risk factors among the following: age ≥ 75 years, history of non-severe fracture after 50 years of age, body mass index < 19 kg/m², at least three comorbidities (e.g., cardiovascular disease, depression, Parkinson's disease, and dementia), current glucocorticoid therapy, and repeated falls. When the decision is difficult, FRAX^® score determination and an assessment by a bone disease specialist may be helpful. When osteoporosis therapy is not indicated, general measures should be applied, and bone mineral density measured again after 12-24 months. The anti-tumor effects of bisphosphonates and denosumab fall outside the scope of these recommendations.

Food Fortification and Supplement Use-Are There Health Implications?

Dietary supplements are a multi-billion dollar industry in the U.S., and their use is increasing exponentially. Additionally, many foods and beverages are increasingly being fortified with single or multiple vitamins and minerals. Consequently, nutrient intakes are exceeding the safe limits established by the Institute of Medicine. In this paper, we examine the benefits and drawbacks of vitamin and mineral supplements and increasing consumption of fortified foods (in addition to dietary intake) in the U.S.

POPULATION

The pros and cons are illustrated using population estimates of folic acid, calcium, and vitamin D intake, highlighting concerns related to overconsumption of nutrients that should be addressed by regulatory agencies.

Androgen Deprivation in Veterans with Prostate Cancer: Implications for Skeletal Health

Background:

Common risk factors for osteoporosis in older men include smoking, heavy use of alcohol, propensity to falls, and use of bone-toxic medications such as prednisone. There is also increasing appreciation of the skeletal risk faced by men receiving androgen deprivation therapy (ADT) for prostate cancer. Measures to prevent bone loss in such patients are available.

Objective:

To test the following hypotheses in a population of veterans receiving ADT for prostate cancer: (1) fracture risk factors in addition to androgen deprivation would be found in most patients, (2) bone mass measurements would be assessed in a minority of patients, and (3) a minority of the subjects would receive bisphosphonate therapy or have contraindications for such treatment.

Methods:

We conducted a retrospective chart review of male veterans receiving ADT from 1993 through 2001, at the Veterans Affairs Medical Center, Madison, WI.

Results:

One hundred and seventy-four subjects met study criteria, with a mean age of 76 years and median duration of 21 months of ADT. Eighty-one percent had risk factors in addition to ADT. Only 13% underwent bone density measurement by dual energy X-ray absorptiometry (DXA) and, of those measured, more than half had osteoporosis. Only 19% of the men received both calcium and vitamin D supplements. Antiresorptive therapy was provided to 11% of men, although more than two-thirds had no contraindications to therapy. A total of 24 men sustained a fracture after starting ADT. For men who did undergo bone density measurement, 77% received antiresorptive therapy. Of those who exhibited osteoporosis by DXA scan, 85% received antiresorptive therapy.

Conclusions:

Male veterans receiving ADT for prostate cancer received inadequate evaluation and treatment for osteoporosis. Based on our data, a simple and practical strategy to prompt further evaluation and improved care may be to undertake bone density measurements in men prior to or soon after commencing ADT.

Italian association of clinical endocrinologists (AME) position statement: drug therapy of osteoporosis

Treatment of osteoporosis is aimed to prevent fragility fractures and to stabilize or increase bone mineral density. Several drugs with different efficacy and safety profiles are available. The long-term therapeutic strategy should be planned, and the initial treatment should be selected according to the individual site-specific fracture risk and the need to give the maximal protection when the fracture risk is highest (i.e. in the late life). The present consensus focused on the strategies for the treatment of postmenopausal osteoporosis taking into consideration all the drugs available for this purpose. A short revision of the literature about treatment of secondary osteoporosis due both to androgen deprivation therapy for prostate cancer and to aromatase inhibitors for breast cancer was also performed. Also premenopausal females and males with osteoporosis are frequently seen in endocrine settings. Finally particular attention was paid to the tailoring of treatment as well as to its duration.

Osteoporosis and Low Bone Mineral Density in Men with Testosterone Deficiency Syndrome

INTRODUCTION

Testosterone deficiency syndrome (TDS) is a risk factor for low bone mineral density (BMD) and osteoporosis. Knowledge of the relationship between TDS and bone health, as well as the practical aspects of how to diagnose and treat low BMD, is therefore of practical importance to sexual medicine practitioners.

AIM

The aim of this study was to review the physiologic basis and clinical evidence of the relationship between TDS and bone health; and to provide a practical, evidence-based algorithm for the diagnosis and management of low BMD in men with TDS.

METHODS

Method used was a review of relevant publications in PubMed.

MAIN OUTCOME MEASURES

Pathophysiology of low BMD in TDS, morbidity, and mortality of osteoporosis in men, association between TDS and osteoporosis, indications for dual X-ray absorptiometry (DXA) scanning in TDS, evidence for testosterone replacement therapy (TRT) in men with osteoporosis, treatment for osteoporosis in the setting of TDS.

RESULTS

Sex hormones play a pleomorphic role in maintenance of BMD. TDS is associated with increased risk of osteoporosis and osteopenia, both of which contribute to morbidity and mortality in men. DXA scanning is indicated in men older than 50 years with TDS, and in younger men with longstanding TDS. Men with TDS and osteoporosis should be treated with anti-osteoporotic agents and TRT should be highly considered. Men with osteopenia should be stratified by fracture risk. Those at high risk should be treated with anti-osteoporotic agents with strong consideration of TRT; while those at low risk should be strongly considered for TRT, which has a beneficial effect on BMD.

CONCLUSION

Low BMD is a prevalent and treatable cause of morbidity and mortality in men with TDS. Utilization of a practical, evidence-based approach to diagnosis and treatment of low BMD in men with TDS enables sexual medicine practitioners to make a meaningful impact on patient quality of life and longevity. Gaffney CD, Pagano MJ, Kuker AP, Stember DS, and Stahl PJ. Osteoporosis and low bone mineral density in men with testosterone deficiency syndrome.

Bisphosphonates for osteoporosis in nonmetastatic prostate cancer patients receiving androgen-deprivation therapy: a systematic review and meta-analysis

This systematic review was conducted to assess the efficacy and safety of bisphosphonates for prevention and treatment of osteopenia or osteoporosis in men with non-metastatic prostate cancer receiving androgen- deprivation therapy. We searched for randomised controlled trials (RCTs) of bisphosphonates compared with placebo from Pubmed, Embase, the Cochrane Library, and ISI - Science Citation Index. Meta-analyses of pre- specified outcomes (bone mineral density, fractures, and adverse events) were performed using Review Manager. Ten RCTs with a total patient population of 1,017 were identified. There was generally more improvement in bone mineral density of the lumbar spine for patients who received bisphosphonate treatment than placebo or other medical treatment at 12 months (WMD 6.02,95%CI 5.39 to 6.65). Similar effects were also observed for total hip, trochanter or femoral neck bone mineral density. However, there was no significant reduction in fractures. Fever and gastrointestinal symptoms were the most common adverse events (10.4% vs. 1.2%; 0.10% vs. 0.03%). Currently, our meta-analysis suggested that oral and intravenous bisphosphonates caused a rapid increase in spine and hip or femoral BMD in non-metastatic prostate cancer patients receiving androgen-deprivation therapy. Fever and gastrointestinal symptoms were common with the use of bisphosphonates. These short-term trials (maximum of 12 months) did not show fracture reduction. In future, more efficient performance of higher quality, more rigorous, large sample, long-term randomised controlled trials (>12 months) are needed where outcomes are detailed.

Bone targeted therapies for the prevention of skeletal morbidity in men with prostate cancer

Men with prostate cancer suffer substantially from bone-related complications. Androgen deprivation therapy itself is a cause of loss of bone mineral density and is associated with an increased incidence of osteoporotic fractures. In advanced disease, bone is by far the most common site of metastasis. Complications of bone metastases prominently include pain and the potential for skeletal events such as spinal cord compression and pathologic fractures. Elevated osteoclast activity is an important aspect of the pathophysiology of both treatment-related osteoporosis and skeletal complications due to metastases. The osteoclast is therefore a therapeutic target. Denosumab is a fully human monoclonal antibody to receptor activator of nuclear factor-κ-B ligand that was designed to potently inhibit osteoclast activity and is the central focus of this review. Bisphosphonates, radiopharmaceuticals and systemically-active hormonal agents such as abiraterone acetate and enzalutamide have each been shown to improve skeletal morbidity in specific clinical situations. Denosumab is the only agent that has been shown to prevent osteoporotic fractures in men receiving androgen deprivation therapy and at elevated risk for fracture. It has also demonstrated superiority to the potent bisphosphonate zoledronic acid for the prevention of skeletal-related events in men with castration-resistant prostate cancer metastatic to bone. Efficacy and toxicity data will be discussed.

Current and future treatments of secondary osteoporosis

Osteoporosis is commonly associated with menopause and ageing. It can, however, also be caused by diseases, lifestyle, genetic diseases, drug therapies and other therapeutic interventions. In cases of secondary osteoporosis, a common rule is the management of the underlying condition. Healthy habits and calcium and vitamin D supplementation are also generally advised. In cases of high risk of fracture, specific antiosteoporosis medications should be prescribed. For most conditions, the available evidence is limited. Special attention should be paid to possible contraindications of drugs used for the treatment of postmenopausal or senile osteoporosis. Bisphosphonates are the most widely used drugs in secondary osteoporosis, and denosumab or teriparatide have been also assessed in some cases. Important research is needed to develop more tailored strategies, specific to the peculiarities of the different types of secondary osteoporosis.

Muscle and bone effects of androgen deprivation therapy: current and emerging therapies

Prostate cancer and treatment with androgen deprivation therapy (ADT) affect significant numbers of the male population. Endocrine effects of ADT are a critical consideration in balancing the benefits and risks of treatment on long-term survival and quality of life. This review highlights the latest advances in androgen manipulation in prostate cancer with an emphasis on the effects of ADT on muscle and bone, which universally affects the health and well-being of men undergoing ADT for prostate cancer. Muscle mass declines with ADT; however, the evidence that this correlates with a decrease in muscle strength or a decrease in physical performance is discordant. Cortical bone decay also occurs in association with an increase in fracture risk, hence optimization of musculoskeletal health in men undergoing ADT is crucial. The role of exercise, and current and emerging anabolic therapies for muscle as well as various new strategies to prevent loss of bone mass in men undergoing ADT are discussed. Future well-designed, prospective, controlled studies are required to elucidate the effects of ADT on physical performance, which are currently lacking, and larger randomized controlled trials are required to test the efficacy of medical therapies and exercise interventions to target proven deficits and to ensure safety in men with prostate cancer.

Managing bone metastases and reducing skeletal related events in prostate cancer

Advanced-stage prostate cancer is associated with skeletal complications related to metastatic disease and its treatment. On the one hand, metastatic disease to bone is commonly associated with skeletal-related events (SREs); on the other hand, treatment with androgen-deprivation therapy (ADT) leads to loss in bone mineral density (BMD) and increased risk of fracture. Despite osteoblastic appearance on radiography, bone metastases from prostate cancer are associated with increased osteoblast and osteoclast activity providing the rationale for treatment with osteoclast-targeted agents. The bisphosphonate zoledronic acid and the monoclonal antibody denosumab reduce the incidence of SREs in metastatic castration-resistant prostate cancer (mCRPC). A number of agents prevent loss of BMD associated with ADT, but only denosumab is approved to reduce fractures in patients with non-metastatic prostate cancer. Another recently approved agent-radium-223-improves survival and delays SREs in mCRPC. The inhibitors of androgen receptor signalling, abiraterone and enzalutamide, improve survival in mCRPC and delay SREs, although the latter is likely related to control of disease rather than a direct effect on bone. Finally, the tyrosine kinase inhibitor cabozantinib shows promising activity in bone metastases from mCRPC. This Review addresses the skeletal morbidity associated with prostate cancer and the therapeutic options that exist to treat it.

Optimizing bone health and minimizing skeletal morbidity in men with prostate cancer

Maintaining bone health is important in the management of men with prostate cancer. Patients receiving androgen deprivation therapy are at increased risk for treatment-related osteoporosis, and patients with bone metastases are at increased risk for skeletal morbidity related to debilitating skeletal-related events (SREs). Optimizing bone health in these patients includes lifestyle modifications, calcium/vitamin D supplementation, and osteoclast-targeted agents in select high-risk patients. No agent is approved for the prevention of bone metastases. Novel systemic agents have shown a beneficial effect bone by directly affecting tumor growth. Integration of these anticancer agents with osteoclast-targeted agents warrants further investigation.

A randomized phase II trial evaluating different schedules of zoledronic acid on bone mineral density in patients with prostate cancer beginning androgen deprivation therapy

OBJECTIVE

To assess the effects of timing and schedule of zoledronic acid (ZA) administration on bone mineral density (BMD) in patients beginning androgen deprivation therapy (ADT) for the treatment of recurrent prostate cancer.

PATIENTS AND METHODS

In this randomized, 3-arm trial, we evaluated changes in BMD after 3 different ZA administration schedules in men with recurrent prostate cancer who were beginning ADT. Forty-four patients were enrolled and randomized to receive a single dose of ZA given 1 week before beginning ADT (arm 1), a single dose of ZA given 6 months after beginning ADT (arm 2), or monthly administration of ZA starting 6 months after beginning ADT, for a total of 6 doses (arm 3).

RESULTS

Patients who received ZA before ADT had a significant improvement in BMD at the total proximal femur and trochanter after 6 months compared with the other groups. In addition, only patients in the arm that received multiple doses improved lumbar spine BMD while on ADT, with these findings persisting to 24 months. However, this group also experienced more grade 1 adverse events.

CONCLUSIONS

Analysis of these data suggests that ZA administration before initiation of ADT was superior to treatment 6 months after starting ADT in maintaining BMD. In addition, monthly ZA administration can increase BMD above baseline but is associated with more adverse events. Further study is needed to examine whether the timing and frequency of ZA therapy in patients on ADT can reduce fracture risk.

Bone-targeted agents: preventing skeletal complications in prostate cancer

In men, prostate cancer is the most common non-cutaneous malignancy and the second most common cause of cancer death. Skeletal complications occur at various points during the disease course, either due to bone metastases directly, or as an unintended consequence of androgen deprivation therapy (ADT). Bone metastases are associated with pathologic fractures, spinal cord compression, and bone pain and can require narcotics or palliative radiation for pain relief. ADT results in bone loss and fragility fractures. This review describes the biology of bone metastases, skeletal morbidity, and recent advances in bone-targeted therapies to prevent skeletal complications of prostate cancer.

Calcium and vitamin D supplementation during androgen deprivation therapy for prostate cancer: a critical review

BACKGROUND

Loss of bone mineral density is an unintended consequence of androgen deprivation therapy in men with prostate cancer. Supplementation with calcium and/or vitamin D in these men seems logical and is advocated by many lay and professional groups.

METHODS

We reviewed guidelines for calcium and vitamin D supplementation and the results of clinical trials of calcium and vitamin D supplementation on bone mineral density in men with prostate cancer undergoing androgen deprivation therapy.

RESULTS

Whether supplementation of men undergoing androgen deprivation therapy with calcium and/or vitamin D results in higher bone mineral density than no supplementation has not been tested. The results of 12 clinical trials show that, at the doses commonly recommended, 500-1,000 mg calcium and 200-500 IU vitamin D per day, men undergoing androgen deprivation lose bone mineral density.

CONCLUSION

The doses of calcium and vitamin D that have been tested are inadequate to prevent loss of bone mineral density in men undergoing androgen deprivation therapy. In light of evidence that high levels of dietary calcium and calcium supplement use are associated with higher risks for cardiovascular disease and advanced prostate cancer, intervention studies should evaluate the safety as well as the efficacy of calcium and vitamin D supplementation in these men.

Emerging therapies to prevent skeletal morbidity in men with prostate cancer

Skeletal morbidity is a prominent burden to men with advanced prostate cancer throughout the natural history of the disease. Bone metastases can cause pain and greatly elevate the risk for fractures and other structural complications. Distinct from the problem of metastases, treatment-related osteoporosis and associated fragility fractures are potential complications of androgen-deprivation therapy. Bone-targeted therapies for prostate cancer have therefore been the focus of considerable research and drug development efforts. The osteoclast is a validated therapeutic target in the management of prostate cancer. Osteoclast inhibition with zoledronic acid (a bisphosphonate) or with denosumab (a monoclonal antibody to RANK ligand) reduces risk for skeletal events in men with castration-resistant prostate cancer metastatic to bone. Osteoclast inhibition with any of several bisphosphonates improves bone mineral density, a surrogate for osteoporotic fracture risk. Denosumab and toremifene (a selective estrogen receptor modulator) have each been shown to reduce osteoporotic fracture risk among men receiving androgen-deprivation therapy. Beta-emitting radiopharmaceuticals reduce pain due to metastatic disease. Investigations involving alpha-emitting radium-223, endothelin-A receptor antagonists atrasentan and zibotentan, proto-oncogene tyrosine-protein kinase (SRC) inhibitor dasatinib, and tyrosine kinase inhibitor cabozantinib (XL184) are ongoing in clinical trials and are also discussed.

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.

Contemporary therapeutic approaches targeting bone complications in prostate cancer

Skeletal complications are major causes of morbidity in patients with prostate cancer. Despite the osteoblastic appearance of prostate cancer bone metastases, elevated serum and urinary markers of bone resorption are indicative of high osteoclast activity. Increased osteoclast activity is independently associated with subsequent skeletal complications, disease progression, and death. Osteoclast-targeted therapies aim to reduce the risk for disease-related skeletal complications, bone metastases, and treatment-related fractures. This review focuses on recent advances in osteoclast-targeted therapies in the treatment and prevention of bone complications in prostate cancer. Osteoclast-targeted therapies have been extensively studied in men with prostate cancer. The potent bisphosphonate zoledronic acid significantly decreased the risk of skeletal complications in men with castration-resistant prostate cancer and bone metastases, and is Federal Drug Administration approved for this indication. Denosumab is a human monoclonal antibody that inhibits receptor activator of nuclear factor-κB (RANK) ligand, a critical mediator of osteoclast differentiation, activation, and survival. Data from recent phase III clinic trials demonstrate the emerging role for denosumab in the treatment of prostate cancer bone metastases and prevention of fractures associated with androgen deprivation therapy.

Treatment and prevention of bone complications from prostate cancer

Bone metastases and skeletal complications are major causes of morbidity in prostate cancer patients. Despite the osteoblastic appearance of bone metastases on imaging studies, patients have elevated serum and urinary markers of bone resorption, indicative of high osteoclast activity. Increased osteoclast activity is independently associated with higher risk of subsequent skeletal complications, disease progression, and death. Osteoclast-targeted therapies are therefore a rational approach to reduction of risk for disease-related skeletal complications, bone metastases, and treatment-related fractures. This review focuses on recent advances in osteoclast-targeted therapy in prostate cancer. Bisphosphonates have been extensively studied in men with prostate cancer. Zoledronic acid significantly decreased the risk of skeletal complications in men with castration-resistant prostate cancer and bone metastases, and it is FDA-approved for this indication. Denosumab is a human monoclonal antibody that binds and inactivates RANKL, a critical mediator of osteoclast differentiation, activation, and survival. Recent global phase 3 clinic trials demonstrated an emerging role for denosumab in the treatment of prostate cancer bone metastases and prevention of fractures associated with androgen deprivation therapy.

Bone health and prostate cancer

Bone metastases are a substantial burden to men with advanced prostate cancer as they often cause pain and can cause fractures and spinal cord compression. Osteoblasts and osteoclasts are both pathologically activated in the setting of prostate cancer bone metastases. As osteoclast activation is associated with disease progression, skeletal complications and death, osteoclast-targeted therapies are a rational approach to disease management. Zoledronic acid is standard of care for castration-resistant prostate cancer with bone metastases as it reduces the risk for skeletal-related events. Additional trials are needed to better define the ideal dose, frequency and duration of zoledronic acid therapy. No bisphosphonate has yet been shown to prevent bone metastases or to benefit men with androgen-sensitive disease. Denosumab is an experimental osteoclast-targeted monoclonal antibody against receptor activator of nuclear factor-kappaB ligand. Two ongoing phase III trials are expected to define its efficacy in preventing bone metastases and disease-related skeletal events in men with prostate cancer. Androgen-deprivation therapy (ADT) for prostate cancer is associated with osteoporosis and fragility fractures. Several bisphosphonates have been shown to improve bone mineral density in men receiving ADT. Two recent phase III trials have shown that denosumab and toremifene reduce the incidence of fragility fractures in these men. The World Health Organization has developed a fracture risk assessment model (FRAX) for the general population to guide the selection of patients who may benefit from pharmacotherapy. In the absence of a prostate cancer-specific algorithm, we advocate the use of FRAX for men receiving ADT.

Cancer treatment-induced bone loss in breast and prostate cancer

PURPOSE

Bone loss resulting from the treatment of breast and prostate cancer is an emerging problem. Bisphosphonates have a potential role in the prevention of this cancer treatment-induced bone loss (CTIBL).

METHODS

Studies evaluating the incidence and prevalence of CTIBL in early breast and prostate cancer patients and trials evaluating the preventative role of bisphosphonates were identified by a search of the PubMed and Cochrane Library databases through the end of March 2008. Reference lists from retrieved articles were cross referenced, and further information was obtained from relevant scientific meetings.

RESULTS

Several therapies commonly used in the treatment of women and men with breast and prostate cancers, in particular the aromatase inhibitors (AIs) for breast cancer and androgen deprivation therapy (ADT) for prostate cancer, are associated with significant bone loss and with an increase in fracture risk. The use of bisphosphonates seems to attenuate the bone loss, although the long-term impact remains unclear because of insufficient follow-up.

CONCLUSION

Adjuvant endocrine therapy with an AI or androgen deprivation can be considered a risk factor for the development of osteopenia, osteoporosis, and bone fracture, which can be mitigated by appropriate bisphosphonate therapy. Clear identification of risk factors for osteoporosis in individual patients should aid treatment decisions about whether to use bisphosphonates when starting or switching to an AI or ADT. Patients need to be educated about this risk and other measures to avoid this complication, including lifestyle modifications that may benefit their general and bone health.

Drug insight: the use of bisphosphonates for the prevention and treatment of osteoporosis in men

Osteoporosis has long been recognized as a disease affecting postmenopausal women but it has become increasingly clear that men are affected by low bone density and suffer the consequences of osteoporotic fractures. Men attending clinical urological practices might be at raised risk of bone loss due to hypogonadism, either identified during work-up of erectile dysfunction or induced by androgen deprivation therapy for treatment of prostate cancer. The availability of bisphosphonate drugs with proven efficacy in fracture reduction has revolutionized osteoporosis therapy in the past decade. The use of these agents has been traditionally based on data obtained predominantly from postmenopausal women and cases of glucocorticoid-induced osteoporosis, but data are becoming increasingly available to justify their use in men. Despite the availability and favorable safety profile of bisphosphonates, many patients are not receiving therapy. This article serves to review the data regarding bisphosphonate use in men, discussing particularly the pharmacology and mechanisms of action of these agents, and findings from clinical studies supporting their use for fracture prevention.

Long-term side effects of androgen deprivation therapy in men with non-metastatic prostate cancer: A systematic literature review

Increasing numbers of men with non-metastatic disease are receiving androgen deprivation therapy (ADT) for a variety of indications, some of which are supported by evidence from randomized trials. Balanced against possible survival benefits and better disease control are data that ADT adversely affects quality of life, particularly in the areas of sexual function, physical function, and energy. There is some evidence of worsening upper extremity physical strength but no clear evidence of decline in daily function with ADT. The impact of ADT on cognitive function is not clear at this time. ADT is associated with declines in bone mineral density within 6-12 months of commencing treatment, with increased fracture rates within 5 years of treatment. ADT use is also associated with a 10-15g/L decline in hemoglobin, although the clinical significance of this drop appears to be limited for most patients. It is reasonable for physicians who are about to start men on ADT to obtain a baseline bone mineral density, to counsel them about the impact on sexual function and possible treatments for sexual dysfunction, and to encourage regular exercise. Further insight into adverse effects of ADT and strategies to minimize these adverse effects await data from ongoing studies.

The role of bisphosphonates in the treatment of prostate cancer: recommendations from an expert panel

In this study, we provide consensus guidelines for the use of bisphosphonates in men with prostate cancer. To this end, an expert panel composed of urologists, medical oncologists, radiation oncologists, and endocrinologists met to review current clinical evidence for the use of bisphosphonates in patients with different stages of prostate cancer to derive consensus recommendations. Physicians should be proactive in monitoring bone loss in patients receiving long-term androgen-deprivation therapy for prostate cancer. Further study is needed before recommending the routine use of bisphosphonates in men with nonmetastatic prostate cancer. However, if a patient has clinically significant bone loss, use of a bisphosphonate to prevent further compromise of bone integrity should be strongly considered, regardless of hormonal and metastatic status. Bone scans are the preferred method for the identification of bone metastases. In patients with hormone-refractory prostate cancer and bone metastases, zoledronic acid is the only bisphosphonate indicated for the prevention of skeletal complications. In conclusion, patients with prostate cancer are at high risk for skeletal morbidity. Bisphosphonates have been shown to prevent cancer treatment-induced bone loss in men receiving androgen-deprivation therapy as well as skeletal complications in men with bone metastases. However, further study of the use of bisphosphonates across the clinical spectrum of prostate cancer is needed.

The role of bisphosphonates in preventing skeletal complications of hormonal therapy

Androgen deprivation therapy (ADT) is associated with a significant decrease in bone mineral density (BMD), and continued exposure seems to increase the risk of osteoporotic fracture in men who have prostate cancer treated with this strategy. Men who have prostate cancer may have low BMD before initiation of ADT. Bisphosphonates are pyrophosphate analogs that decrease bone resorption primarily through direct inhibition of osteoclast activity and proliferation. Several bisphosphonates have been evaluated in randomized clinical trials, and the cumulative data show that these medications increase or maintain BMD in men receiving ADT for prostate cancer. The effect on clinical fractures has not been assessed adequately, but bisphosphonates offer an important potential treatment modality to reduce the risk of osteoporotic fracture in this population of men.

The management of secondary osteoporosis

Secondary osteoporosis is common among patients being evaluated for osteoporosis. All men and premenopausal women with unexplained bone loss or a history of a fragility fracture should undergo a work-up for secondary osteoporosis. Also, postmenopausal women with risk factors for secondary osteoporosis should be carefully evaluated. The evaluation should include a thorough history, physical examination, bone mineral density testing, and laboratory testing. While there is no consensus for a cost-effective laboratory evaluation, some recommendations include: 25-hydroxyvitamin D, parathyroid hormone (PTH), serum and urine calcium, phosphate, creatinine, liver function tests, a complete blood count, testosterone in men, and thyroid-stimulating hormone. After a thorough review of the evaluation for secondary osteoporosis, this chapter reviews the pathophysiology and treatment of secondary osteoporotic disorders, including vitamin D insufficiency, osteomalacia, the osteoporosis of erosive inflammatory arthritis, ankylosing spondylitis, systemic lupus erythematosus, and osteoporosis related to anti-androgenic therapy for prostate cancer and aromatase inhibitor therapy for breast cancer. Physicians have a significant responsibility to evaluate and treat the underlying medical problem that is the cause of secondary osteoporosis and to optimize bone health in the individual patient.

The use of bisphosphonates in the treatment of osteoporosis

PURPOSE OF REVIEW

The bisphosphonates alendronate and risedronate, given orally once weekly, are the cornerstone of treatment of postmenopausal osteoporosis, as well as of male and secondary osteoporosis. They reduce significantly the risk of vertebral and nonvertebral fractures; their effects appear early, within 6-12 months, and appear to be sustained. Several questions remain unanswered, however. In addition, data on a new bisphosphonate became available in 2004.

RECENT FINDINGS

The optimal duration of treatment has not been clearly established. Long-term data with alendronate are now available, indicating a persistence of alendronate effects on bone mineral density and bone turnover markers several years after stopping treatment given for 5 years. Whether these effects translate into sustained reduction of fractures needs to be further analyzed. Because of their efficacy, bisphosphonate use has been explored in other forms of osteoporosis, such as after androgen deprivation therapy for prostatic cancer. The challenge of long-term compliance with treatment of osteoporosis has triggered the use of intermittent bisphosphonate. The effects of intermittent oral and intravenous ibandronate on bone mineral density, bone turnover, and fractures have been recently reported.

SUMMARY

The mechanism by which bisphosphonates improve bone strength is not yet fully understood but probably involves complex effects on different components of bone strength, such as microarchitecture.

Effects of neridronate treatment in elderly women with osteoporosis

Osteoporosis is a common disorder, especially among elderly post-menopausal women. Elderly women are often affected by co-morbidities, impaired gastrointestinal function and reduced mobility; therefore, the treatment strategy for their osteoporosis can be difficult. In this randomized pilot study, we have investigated the effects of a 12-month treatment with neridronate on bone mineral density (BMD), bone turnover markers and quality of life (QoL). The study included 40 women (age, 65-80 yr; post-menopausal period, >15yr) from a single osteoporosis centre. Twenty women received a monthly im injection of 25 mg of neridronate associated with a daily dose of 500 mg of calcium and 400 U of vitamin D. Twenty women received calcium plus vitamin D supplements alone. Changes in BMD at the lumbar spine and femoral neck were measured by dual energy X-ray absorptiometry. Serum type I collagen C-telopeptide (sCTX), urinary free-deoxypyridinoline (ufDPD), bone alkaline phosphatase (ALP) and serum osteocalcin levels were determined. For the QoL assessment, the Italian version of the SF-36 test was administrated. Spine and hip BMD rose by 6.6 +/- 3 and 4.2 +/- 2.3%, respectively (p < 0.05), after 12 months of neridronate treatment. Markers of skeletal turnover significantly fell already after 3 months of neridronate treatment and decreased progressively thereafter within 12 months. The mean decrease at 12 months ranged from 38 +/- 11% for sCTX to 25.2 +/- 15% for ufDPD (p < 0.001, all). The mean improvement in QoL in the treated group was 45.7% for bodily pain, 37.5% for general health perception, 23.1% for vitality, 18% for emotional role functioning and 12% for physical role functioning. The changes observed in BMD, turnover markers and QoL in the untreated group were ns. The intermittent neridronate administration was easily manageable and well tolerated. In conclusion, neridronate currently represents a valid option for the treatment of osteoporosis, since it helps just as much as oral BPs in the improvement of BMD and in particular conditions it can be even more effective.