Progressive decrease in bone density over 10 years of androgen deprivation therapy in patients with prostate cancer

Measurement of bone turnover in prostate cancer patients receiving intermittent androgen suppression therapy

Purpose

Reports on clinical measurements of bone mineral density (BMD) in prostate cancer patients undergoing intermittent androgen suppression therapy (IAS) that allows for hormonal recovery between treatment cycles indicate decreased osteoporosis compared to continuous androgen suppression therapy (CAS). In the present study the effect of IAS on bone metabolism by determinations of CrossLaps, a biochemical marker of collagen degradation, were examined.

Method

In total 100 IAS treatment cycles of 75 patients with prostate cancer stages ≥ pT2 were studied. Clinical data and monthly laboratory tests (testosterone, prostate-specific antigen; PSA) of these patients were monitored together with measurements of C-terminal telopeptide collagen fragments using CrossLaps® ELISA assays.

Results

During phases of androgen suppression (AS) lasting for 9 months serum testosterone (<1 ng/mL) and PSA (<2 ng/mL) levels were reversibly reduced, indicating partial growth arrest and apoptotic regression of the prostatic tumors. Serum CrossLaps concentrations peaked at the last 2 months of the AS phases (0.91 ± 0.25 μg/L; mean ± SEM) and were reduced below initial values (0.21 ± 0.43 versus baseline of 0.43 ± 0.06 μg/L) during therapy cessation periods until tumor progression-related increases.

Conclusion

Measurements of the serum concentration of CrossLaps in prostate cancer patients receiving IAS indicated that treatment cessation phases rapidly reversed increased bone degradation associated with AS phases, in strong agreement with the clinical observations reporting reduced loss of BMD in IAS when compared to CAS. In terms of clinical outcomes, IAS seems to be as effective as CAS while showing reduced side effects, as demonstrated here by the reduction of androgen-induced bone matrix degradation.

Innovations in the systemic therapy of prostate cancer

Systemic therapy has become an increasingly important component of treatment of advanced prostate cancer. In the past decade, important innovations have been achieved in the development of novel systemic hormonal therapies for the salvage treatment of metastatic castrate-resistant disease. These improvements have been accompanied by the broadening of potential indications for chemotherapy in castrate-resistant metastatic disease and the use of chemotherapy as an adjunct to the treatment of locally extensive tumors. These changes have begun to lead to improved outcomes, but at the expense of novel patterns of late toxic effects. We review the key steps in the recent evolution of systemic therapy of prostate cancer.

Correlates of trabecular and cortical volumetric BMD in men of African ancestry

QCT provides a measure of volumetric BMD (vBMD) and distinguishes trabecular from cortical bone. Few studies have determined the factors related to vBMD in men, especially among men of African heritage. This study evaluated the relationship of anthropometric, medical, and behavioral factors and vBMD in a population-based cohort of men of African ancestry (n = 1901) >or=40 yr of age who had undergone screening for prostate cancer for the first time. Trabecular and cortical vBMD were measured at the radius and tibia by pQCT. Multiple linear regression analysis identified age, height, body weight, cigarette smoking, history of diabetes, fracture, and prostate cancer as the independent correlates of vBMD. However, associations with several variables differed between cortical and trabecular vBMD and between the radius and tibia. Longitudinal studies are needed to gain a better understanding of the mechanisms underlying these differential associations that may show new insight into the etiology of trabecular and cortical bone loss in men.

The quantitative ADAM questionnaire: a new tool in quantifying the severity of hypogonadism

Androgen deficiency is a pervasive problem in the older male population and is thought to be responsible for many symptoms once considered to be the result of normal aging. Numerous methods have been proposed to facilitate the detection of men at risk for androgen deficiency. In this article, we propose a novel screening tool, the quantitative Androgen Deficiency in the Aging Male (qADAM) questionnaire and report its successful use in quantifying the severity of androgen deficiency in a group of older men. Fifty-seven males scheduled to undergo radical prostatectomy for prostate cancer completed the qADAM as well as the Sexual Health Inventory for Men (SHIM) and the Expanded Prostate Cancer Index Composite hormonal/sexual (EPICh/EPICs) questionnaires. Thirty-four men also had serum testosterone levels measured for comparison. The qADAM showed statistically significant correlation to the SHIM (P=0.001), EPICh (P=0.016), EPICs (P=<0.001), and serum testosterone (P=0.046). The qADAM represents a viable alternative to existing questionnaires used to detect androgen deficiency and to assess response to treatment.

Review of major adverse effects of androgen-deprivation therapy in men with prostate cancer

Androgen-deprivation therapy (ADT) is a common treatment for men with prostate cancer. Although ADT is effective at suppressing prostate-specific antigen (PSA), stabilizing disease, alleviating symptoms in advanced disease, and potentially prolonging survival, it is not without serious side effects. However, to the authors' knowledge, there is lack of a systematic review of its major adverse effects to date. The authors of this report systematically reviewed and quantitatively assessed the literature on skeletal and cardiac side effects associated with ADT in men with prostate cancer. The PubMed database was searched for relevant published articles from 1966 to May 2008, and 683 articles were reviewed systematically from an original 20 different Medical Subject Heading search combinations. The focus of the review was on bone-related and cardiovascular-related outcomes. When appropriate, results were pooled from articles on specific adverse outcomes, summary risk estimates were calculated, and tests of heterogeneity were performed. Fourteen articles were identified that met inclusion criteria from the original 683 studies. Men who underwent ADT for prostate cancer had a significantly increased risk of overall fracture of 23% (summary relative risk, 1.23; 95% confidence interval [95% CI], 1.10-1.38) compared with men who had prostate cancer but who did not undergo ADT. Furthermore, men who underwent ADT had a 17% increase in cardiovascular-related mortality compared with men who did not undergo with ADT (summary hazards ratio, 1.17; 95% CI, 1.07-1.29). Significant elevations in the risk of diabetes also were observed from 2 large studies. ADT was associated with an increased risk of skeletal fracture, incident diabetes, and cardiovascular-related mortality, although the absolute risk of these events was low. Preventive measures against these adverse effects and careful assessment of patient's baseline health status should be considered.

Natural history and correlates of hip BMD loss with aging in men of African ancestry: the Tobago Bone Health Study

Little is known about the magnitude, pattern, and determinants of bone loss with advancing age among men, particularly among those of African descent. We examined the rate of decline in hip BMD and identified factors associated with BMD loss among 1478 Afro-Caribbean men >or=40 yr of age. BMD was measured at baseline and after an average of 4.4 yr by DXA. The rate of decline in femoral neck BMD was 0.29 +/- 0.81%/yr in the total sample (p < 0.0001). However, a U-shaped relationship between advancing age and the rate of decline in BMD was observed. The rate of decline in BMD at the femoral neck was -0.38 +/- 0.77%/yr among men 40-44 yr of age, decelerated to -0.15 +/- 0.81%/yr among men 50-54 yr of age, and then accelerated to -0.52 +/- 0.90%/yr among those 75+ yr of age (all p < 0.003). Men who lost >or=5% of their body weight during follow-up had significantly greater BMD loss than those who remained weight stable or gained weight (p < 0.0001). The relationship between weight loss and BMD loss was more pronounced among men who were older and leaner at study entry (p < 0.03). We also observed a strong impact of advanced prostate cancer and its treatment with androgen deprivation on BMD loss. Men of African ancestry experience substantial BMD loss with advancing age that seems to be comparable to the rate of loss among white men in other studies. Additional studies are needed to better define the natural history and factors underlying bone loss with aging in men of African ancestry.

Implementation of osteoporosis screening guidelines in prostate cancer patients on androgen ablation

Androgen ablation (AA) therapy is one of the modalities used to treat prostate cancer. It is well known that AA therapy increases the risk of osteoporosis and fractures. In 2004, the British Columbia Cancer Agency published guidelines regarding bone health in these patients. A key recommendation was to arrange for bone mineral density (BMD) testing if AA was to be used for 6 mo or longer. Our objective was to evaluate how well these guidelines were implemented by reviewing the number of BMDs performed in patients who had been treated at one of the 4 cancer centers in British Columbia. We found that the overall number of BMDs documented after the implementation of the guidelines was significantly greater than the number documented before (25% vs 7.5%, p value < 0.0001). There appeared to be regional differences in implementation, with the greatest effect seen at the Vancouver center, which serves as the chief academic center for the province. The greater effect of guidelines at this center suggests a need for more effective dissemination peripherally. The care gap remaining at even the most impacted center indicates a need for greater efforts to both implement guidelines and monitor their implementation over time.

A phase III clinical trial of exercise modalities on treatment side-effects in men receiving therapy for prostate cancer

Background

Androgen deprivation therapy (ADT) is accompanied by a number of adverse side effects including reduced bone mass and increased risk for fracture, reduced lean mass and muscle strength, mood disturbance and increased fat mass compromising physical functioning, independence, and quality of life. The purpose of this investigation is to examine the effects of long term exercise on reversing musculoskeletal-related side effects, and cardiovascular and diabetes risk factors in men receiving androgen deprivation for their prostate cancer. Specifically, we aim to investigate the effects of a 12-month exercise program designed to load the musculoskeletal system and reduce cardiovascular and diabetes disease progression on the following primary endpoints: 1) bone mineral density; 2) cardiorespiratory function and maximal oxygen capacity; 3) body composition (lean mass and fat mass); 4) blood pressure and cardiovascular function; 5) lipids and glycemic control; and 6) quality of life and psychological distress.

Methods/Design

Multi-site randomized controlled trial of 195 men (65 subjects per arm) undergoing treatment for prostate cancer involving ADT in the cities of Perth and Brisbane in Australia. Participants will be randomized to (1) resistance/impact loading exercise, (2) resistance/cardiovascular exercise groups and (3) usual care/delayed exercise. Participants will then undergo progressive training for 12 months. Measurements for primary and secondary endpoints will take place at baseline, 6 and 12 months (end of the intervention).

Discussion

The principal outcome of this project will be the determination of the strength of effect of exercise on the well established musculoskeletal, cardiovascular and insulin metabolism side effects of androgen deprivation in prostate cancer patients. As this project is much longer term than previous investigations in the area of exercise and cancer, we will gain knowledge as to the continuing effects of exercise in this patient population specifically targeting bone density, cardiovascular function, lean and fat mass, physical function and falls risk as primary study endpoints. In terms of advancement of prostate cancer care, we expect dissemination of the knowledge gained from this project to reduce fracture risk, improve physical and functional ability, quality of life and ultimately survival rate in this population.

Clinical Trial Registry

A Phase III clinical trial of exercise modalities on treatment side-effects in men receiving therapy for prostate cancer; ACTRN12609000200280

Osteoporosis prevention in prostate cancer patients receiving androgen ablation therapy: placebo-controlled double-blind study of estradiol and risedronate: N01C8

PURPOSE

The purpose of this study is to test the ability of risedronate and estradiol, alone or in combination, to prevent bone loss associated with androgen deprivation therapy in men with prostate cancer.

MATERIALS AND METHODS

This is a randomized placebo-controlled trial of risedronate and estradiol, alone or in combination, in men with prostate cancer receiving androgen deprivation therapy. The primary outcome was change in hip bone mineral density at 1 year.

RESULTS

No statistical difference was found among the groups for bone mineral density changes. The only side effects of note were increased gynecomastia and breast tenderness associated with estrogen therapy. The study was limited by poor accrual and subsequent lack of statistical power.

CONCLUSIONS

Men receiving androgen deprivation therapy for prostate cancer are at risk for bone loss and should receive appropriate bone density monitoring and preventive advice about calcium, vitamin D, exercise, and fall prevention. Prescription drugs proven in this patient population should be used when the risk of fracture is high.

Skeletal sequelae of cancer and cancer treatment

INTRODUCTION

Survivors of cancer may experience lingering adverse skeletal effects such as osteoporosis and osteomalacia. Skeletal disorders are often associated with advancing age, but these effects can be exacerbated by exposure to cancer and its treatment. This review will explore the cancer and cancer treatment-related causes of skeletal disorders.

METHODS

We performed a comprehensive search, using various Internet-based medical search engines such as PubMed, Medline Plus, Scopus, and Google Scholar, for published articles on the skeletal effects of cancer and cancer therapies.

RESULTS

One-hundred-forty-two publications, including journal articles, books, and book chapters, met the inclusion criteria. They included case reports, literature reviews, systematic analyses, and cohort reports. Skeletal effects resulting from cancer and cancer therapies, including hypogonadism, androgen deprivation therapy, estrogen suppression, glucocorticoids/corticosteroids, methotrexate, megestrol acetate, platinum compounds, cyclophosphamide, doxorubicin, interferon-alpha, valproic acid, cyclosporine, vitamin A, NSAIDS, estramustine, ifosfamide, radiotherapy, and combined chemotherapeutic regimens, were identified and described. Skeletal effects of hyperparathyroidism, vitamin D deficiency, gastrectomy, hypophosphatemia, and hyperprolactinemia resulting from cancer therapies were also described.

DISCUSSION/CONCLUSIONS

The publications researched during this review both highlight and emphasize the association between cancer therapies, including chemotherapy and radiotherapy, and skeletal dysfunction.

IMPLICATIONS FOR CANCER SURVIVORS

These studies confirm that cancer survivors experience a more rapid acceleration of bone loss than their age-matched peers who were never diagnosed with cancer. Further studies are needed to better address the skeletal needs of cancer survivors.

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.

Skeletal health after continuation, withdrawal, or delay of alendronate in men with prostate cancer undergoing androgen-deprivation therapy

PURPOSE

Androgen-deprivation therapy (ADT) for prostate cancer is associated with bone loss and osteoporotic fractures. Our objective was to examine changes in bone density and turnover with sustained, discontinued, or delayed oral bisphosphonate therapy in men receiving ADT.

PATIENTS AND METHODS

A total of 112 men with nonmetastatic prostate cancer receiving ADT were randomly assigned to alendronate 70 mg once weekly or placebo in a double-blind, partial-crossover trial with a second random assignment at year 2 for those who initially received active therapy. Outcomes included bone mineral density and bone turnover markers.

RESULTS

Men initially randomly assigned to alendronate and randomly reassigned at year 2 to continue had additional bone density gains at the spine (mean, 2.3% +/- 0.7) and hip (mean, 1.3% +/- 0.5%; both P < .01); those randomly assigned to placebo in year 2 maintained density at the spine and hip but lost (mean, -1.9% +/- 0.6%; P < .01) at the forearm. Patients randomly assigned to begin alendronate in year 2 experienced improvements in bone mass at the spine and hip, but experienced less of an increase compared with those who initiated alendronate at baseline. Men receiving alendronate for 2 years experienced a mean 6.7% (+/- 1.2%) increase at the spine and a 3.2% (+/- 1.5%) at the hip (both P < .05). Bone turnover remained suppressed.

CONCLUSION

Among men with nonmetastatic prostate cancer receiving ADT, once-weekly alendronate improves bone density and decreases turnover. A second year of alendronate provides additional skeletal benefit, whereas discontinuation results in bone loss and increased bone turnover. Delay in bisphosphonate therapy appears detrimental to bone health.

Valid treatment options for osteoporosis and osteopenia in HIV-infected persons

OBJECTIVE

To review clinical data on bone ossification agents that may be considered for use in the treatment of osteoporosis and osteopenia in HIV-infected patients.

DATA SOURCES

A literature search was performed using MEDLINE (1950-January 2008), EMBASE, PubMed, and abstracts from major HIV conferences (February 2001-October 2007). These searches were limited to human data published in English and used the key words bisphosphonates, calcitonin, raloxifene, teriparatide, HAART, osteopenia, osteoporosis, and HIV/AIDS. Additional articles were retrieved from citations of selected references.

STUDY SELECTION AND DATA EXTRACTION

Relevant information on the pharmacology, pharmacokinetics, safety, and efficacy of available treatment with hormonal and nonhormonal agents was selected. Greater emphasis was placed on randomized clinical trials than on retrospective studies.

DATA SYNTHESIS

Osteoporosis in HIV-infected persons is at least as prevalent as in postmenopausal women, yet this population is not listed in primary care guidelines as one that should be considered for screening. In addition to bisphosphonates, calcitonin, raloxifene, and teriparatide are used to treat bone disorders. Three clinical trials to date have evaluated the use of a bisphosphonate in HIV-infected persons. The trials showed a marked increase in bone mineral density in patients taking alendronate versus those in the control groups (with/without calcium, exercise, and/or vitamin D in 1 or both arms). Dosing restrictions complicate the use of these agents; diet, exercise, and calcium supplementation remain the foremost recommended strategies to prevent bone loss. The use of estrogen, testosterone, calcitonin, and teriparatide is less studied in HIV-positive patients, but may be considered in select cases. There are some investigational drugs and agents not available in the US; however, there are not enough data to support their use.

CONCLUSIONS

Alendronate appears to be a promising treatment option for HIV-infected patients with osteoporosis and osteopenia. Further research is required to determine the safety and efficacy of other available drugs. Until additional information is provided, and with available knowledge on the metabolism profiles of antiretroviral and bone ossification agents, alendronate appears to be the preferred agent to use in this population.

Update in systemic therapy of prostate cancer: improvement in quality and duration of life

Overall survival benefit with a docetaxel and prednisone regimen in metastatic androgen-independent prostate cancer marked a major advance in the management of prostate cancer. Immunotherapy, antiangiogenic therapies and targeted agents are areas of active research interest. Simultaneous progress in palliative and supportive care has enabled us to improve the quality of life of advanced prostate cancer patients. Multiple predictors of outcome have been reported, and systemic therapy is being actively explored in localized disease. This review attempts to summarize the risk profiling strategy in prostate cancer and the existing therapies in high-risk prostate cancer, including some of the novel agents under investigation.

Bone health in prostate cancer patients receiving androgen-deprivation therapy: the role of bisphosphonates

Androgen-deprivation therapy, a mainstay in the treatment of locally advanced and metastatic prostate cancer, is associated with significant bone loss and related complications, such as fracture. Bisphosphonates, osteoclast inhibitors, are effective in preventing skeletal-related events in patients with metastatic prostate cancer and also in preventing bone loss in patients with locally advanced disease. Understanding the management of bone health, including identifying patients at risk, the most appropriate therapy, and monitoring and managing side effects, is critical. This review provides the most recent bone health risk factor and bisphosphonate data available for prostate cancer patients.

The effect of zoledronic acid on bone mineral density in patients undergoing androgen deprivation therapy

PURPOSE

The aim of this study was to evaluate the efficacy and safety of zoledronic acid compared with placebo in preventing bone mineral density (BMD) loss and suppressing bone markers when initiated during the first year of androgen deprivation therapy in patients with locally advanced prostate cancer.

PATIENTS AND METHODS

Patients were randomized to receive zoledronic acid 4 mg or placebo intravenously every 3 months. Lumbar spine (LS) and total hip BMD was measured using dual-energy x-ray absorptiometry at baseline and at week 52. N-telopeptide (NTX) and bone-specific alkaline phosphatase (BSAP) were evaluated at baseline and every 12 weeks. Safety assessments were performed throughout the study.

RESULTS

Efficacy analyses included 106 patients and 109 patients in the zoledronic acid and placebo groups, respectively. At week 52, the least squares mean BMD percentage differences were 6.7% for LS and 3.7% for total hip (P < 0.0001 for both). In the zoledronic acid group, decreases in NTX ((-)14% to (-)28%) and BSAP ((-)31% to (-)37%) levels were significant and sustained; changes in NTX levels and LS BMD (r = (-)0.25; P = 0.04) and in BSAP levels and hip BMD (r = (-)0.28; P = 0.02) were significantly correlated. Only traumatic fractures were reported for 2 and 3 patients receiving zoledronic acid and placebo, respectively. One patient in each group experienced acute renal failure. Osteonecrosis of the jaw was not reported.

CONCLUSION

Zoledronic acid (4 mg intravenously every 3 months) was safe and effective in preventing bone loss and reducing bone turnover in patients with prostate cancer when initiated during the first year of androgen deprivation therapy; patients with low baseline BMD experienced the greatest benefit.

A clinical trial of 3 doses of transdermal 17beta-estradiol for preventing postmenopausal bone loss: a preliminary study

BACKGROUND

It is well documented that a daily oral dose of 0.625 mg of conjugated equine estrogen or 1-2 mg of 17beta-estradiol is needed to prevent postmenopausal bone loss. Recent studies have indicated that a lower dose of estrogen maybe as effective in maintaining bone mass. The purpose of this study was to evaluate the effects of 3 dosages of transdermally administered 17beta-estradiol gel in postmenopausal women stratified by oophorectomy and natural menopause.

METHODS

One hundred and twenty postmenopausal women were randomly selected to form 4 groups. Three groups of women were treated with a transdermal administration of estradiol gel at a daily dosage of 1.25, 2.5 and 5.0 g (containing 0.75, 1.5, and 3 mg of 17beta-estradiol/day), respectively. The 4th group of women, receiving estriol 2 mg/day p.o., was studied concurrently as a control. Bone mineral density was measured by quantitative computed tomography of the vertebrae from T12 to L3 at baseline, then at 6-month intervals for 1 year.

RESULTS

Women in all groups receiving 17beta-estradiol gel obtained a significant increase in bone mass, with the exception of the 1.25 g/day group, which showed a minimal increment at the 6-month period, compared with the control group. Comparisons of the increments in bone mass after estrogen therapy for both natural and surgical menopausal subjects found that there was a more prominent response in surgical menopausal women receiving a dosage of 2.5 g/day.

CONCLUSION

Estradiol gel at the dosage of 1.25 g/day, equivalent to 17beta-estradiol 0.75 mg/day, effectively prevented bone loss in postmenopausal women after a 12-month treatment period. The therapeutic effect of estradiol gel on bone mass was more prominent in the surgical menopausal groups at the dosage of 2.5 g/day. The atrophic ovaries may therefore play a crucial role in the subsequent decades of postmenopausal women.

Prevalence of Osteoporosis During Long-Term Androgen Deprivation Therapy in Patients with Prostate Cancer

OBJECTIVES

To know the prevalence of osteoporosis in patients with prostate cancer according to the duration of androgen deprivation therapy (ADT).

METHODS

Dual energy x-ray absorptiometry was used to assess the bone mineral density (BMD) at the lumbar spine, femoral neck, Ward's triangle, trochanter, and total hip in 390 patients free of bone metastases. Osteoporosis was diagnosed if a T-score of less than 2.5 was detected at any measurement site. A subset of 124 patients were hormone naive at BMD testing, and 112 had undergone ADT for 2 years, 61 for 4 years, 37 for 6 years, 35 for 8 years, and 21 for 10 years or longer.

RESULTS

The osteoporosis rate was 35.4% in hormone-naive patients, 42.9% after 2 years of ADT, 49.2% after 4 years, 59.5% after 6 years, 65.7% after 8 years, and 80.6% after 10 or more years. Conversely, the rate of normal BMD decreased from 19.4% in hormone-naive patients to 17.8% after 2 years of ADT, 16.4% after 4 years, 10.8% after 6 years, 5.7% after 8 years, and 0% after 10 or more years of ADT.

CONCLUSIONS

The prevalence of osteoporosis seemed high in hormone-naive patients with prostate cancer, and it increased to more than 80% after 10 years of ADT. Because of the increased risk of bone fractures in those patients, clinicians should be aware of the impact of ADT on BMD to prevent bone mass loss.

Height and bone mineral density in androgen insensitivity syndrome with mutations in the androgen receptor gene

INTRODUCTION AND HYPOTHESIS

Androgen insensitivity syndrome (AIS) constitutes a natural model to study effects of androgens and estrogens on growth and bone density. We evaluated height and bone density in patients with AIS with mutations in the androgen receptor (AR) gene.

METHODS

A retrospective analysis was conducted of eight subjects with complete AIS (CAIS) and four with partial AIS (PAIS) submitted to gonadectomy followed by estrogen replacement, and three with PAIS who did not undergo gonadectomy. Standing height and bone mineral apparent density (BMAD) by DXA were measured and compared with male (z (m)) and female (z (f)) reference populations. The z-scores were compared with a value of zero using the one-sample t-test.

RESULTS

Final heights of patients with CAIS and PAIS were intermediate between those predicted for females and males. BMAD of the lumbar spine in CAIS and PAIS after gonadectomy and estrogen replacement (z (f) = - 1.56 +/- 1.04, P = 0.006, and z (m) = - 0.75 +/- 0.89, P = 0.04) indicated vertebral bone deficit, whereas BMAD at the femoral neck was normal. No patient reported fractures.

CONCLUSION

Subjects with AIS had mean final height intermediate between mean normal male and female, and decreased bone mineral density in the lumbar spine. These data suggest an important role for androgens in normal male growth and bone density not replaced by estrogens.

[Non-corticosteroid drug-induced metabolic bone disease]

After osteoporotic fracture or low bone mineral density measurements, it is necessary to look for secondary causes of osteoporosis, such as drugs. Corticosteroids are the most common cause of drug-induced metabolic bone disease. Other drugs responsible for bone disease include: aromatase inhibitors, GnRH agonists, anticonvulsants, heparin, and L thyroxin at TSH-suppressive doses. Confirmation is required of data about neuroleptics and antivitamin K.

Effects of alendronate on bone mineral density in men with prostate cancer treated with androgen deprivation therapy

Bone mineral density (BMD) is low in men with prostate cancer treated with androgen deprivation therapy (ADT). Intravenous bisphosphonates have been shown to prevent the bone loss, however, the effectiveness of oral bisphosphonates have not been studied in this population. In this retrospective cohort study, we examine the effect of alendronate on BMD in men with prostate cancer receiving ADT. We reviewed the charts of patients receiving ADT referred from the VA Urology Clinic for BMD measurements. Forty seven patients had follow up BMD measurements (17.6+8.3 months). Twenty-two men (47%) were also receiving alendronate 70 mg every week. There was a statistically significant difference (p<0.05) in the percent change of BMD per year at the spine (-1.29+/-0.7% vs. +1.41+/-0.7%), total hip (-0.94+/-0.6% vs. +0.97+/-0.5%), femoral neck (-2.17+/-0.7% vs. +0.32+/-0.6%) and trochanter (-2.01+/-0.7% vs. +0.79+/-0.8%) in the patients not treated compared to those treated with alendronate. In the four other measured sites at the radius (proximal, mid, ultra distal and total), there were no statistically significant differences (p>0.05). These findings confirm that bone loss occurs in men receiving ADT at all sites measured. The use of alendronate prevents bone loss at the spine and hip, but does not seem to have the same protective effect at the radius.

Zoledronic acid initiated during the first year of androgen deprivation therapy increases bone mineral density in patients with prostate cancer

PURPOSE

Androgen deprivation therapy in patients with prostate cancer is associated with bone loss and an increased risk of fractures. Zoledronic acid protects against bone mineral density loss when initiated concurrently with androgen deprivation therapy. We evaluated the effect of zoledronic acid initiated subsequent to androgen deprivation therapy on bone mineral density and biochemical markers of bone turnover.

MATERIALS AND METHODS

Patients with prostate cancer without bone metastases who had received androgen deprivation therapy for 12 months or less were randomized to 4 mg zoledronic acid or placebo intravenously every 3 months for 1 year. Patients were stratified according to androgen deprivation therapy duration (less than 6 vs 6 to 12 months). The primary end point was the change in femoral neck and lumbar spine bone mineral density in the 2 groups. The secondary end point was the change in serum bone specific alkaline phosphatase and urine N-telopeptide levels. Total hip bone mineral density was also measured.

RESULTS

The 120 patients with prostate cancer received zoledronic acid (61) or placebo (59). Compared with placebo, zoledronic acid increased femoral neck, total hip and lumbar spine bone mineral density yearly by 3.6% (p = 0.0004), 3.8% (p <0.0001) and 6.7% (p <0.0001), respectively. The effects of zoledronic acid on bone mineral density at these 3 sites were not differentiated according to androgen deprivation therapy duration. Additionally, mean bone specific alkaline phosphatase and N-telopeptide levels were decreased in the zoledronic acid group (each p <0.0001) and were increased in the placebo group (p <0.0001 and p = 0.004, respectively).

CONCLUSIONS

Zoledronic acid increased bone mineral density and suppressed bone turnover markers in patients with prostate cancer without bone metastases when initiated during year 1 of androgen deprivation therapy.

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.

Bone mineral density changes in patients with prostate cancer during the first 2 years of androgen suppression

PURPOSE

We characterized bone mineral density changes in patients with prostate cancer on androgen deprivation therapy during the first 2 years of uninterrupted therapy, and identified which location most reflects bone mass loss.

MATERIALS AND METHODS

Using dual energy x-ray absorptiometry, bone mineral density was prospectively assessed in patients with nonmetastatic prostate cancer at the lumbar spine and femoral neck, Ward's triangle, trochanter and total hip. Measurements were performed at baseline and yearly thereafter in patients on ADT, and at baseline and 1 year in controls (age matched patients with prostate cancer, free of biochemical progression after radical prostatectomy).

RESULTS

A total of 62 patients were included in the study, 31 in each group. Median age (70 and 69 years, respectively), mean Gleason score and mean baseline serum testosterone did not significantly differ. Patients receiving ADT experienced a significant bone mass loss at 12 months in all locations, ranging from 2.29% to 5.55% (p <0.001). In contrast, bone mineral density did not change significantly (0.64% to 1.68%) in patients not receiving ADT. In the 20 patients on ADT after 24 months, the second year decrease was not as severe, nor was it significant compared to first year values. The major bone mass loss occurred in Ward's triangle, with decreases of 5.55% at 12 months and 7.05% at 24 months.

CONCLUSIONS

Bone mineral density decreases during the first 24 months of androgen suppression with the most relevant effect occurring in the first year. Ward's triangle is the axial skeletal site that reflects the major bone mass loss. Because the deleterious impact of long-term androgen suppression on bone mineral density is inversely related to fracture risk and indirectly related to survival in patients with prostate cancer, early diagnosis and prevention of bone mass loss are warranted in these patients.

Prostate cancer, osteoporosis and fracture risk

Prostate cancer is often treated with androgen deprivation therapy (ADT). Although this treatment is effective the associated hypogonadism causes accelerated bone loss, osteoporosis and increased fracture risk in men with prostate cancer, even in the absence of bone metastases. In addition to the negative effects of ADT on bone metabolism, men with prostate cancer are at increased risk of osteoporosis due to advanced age, poor nutrition and vitamin D deficiency. Some treatments for prostate cancer avoid this side effect and these are discussed, together with treatment strategies to minimise the impact of ADT on bone health.

Biphosphonates in Advanced Prostate and Renal Cell Cancer – Current Status and Potential Applications

OBJECTIVE

This review summarizes recent findings on the therapeutic benefits of biphosphonates in patients with advanced prostate or renal cell carcinoma (RCC). The role of biphosphonates in ADT-induced osteoporosis and delay of skeletal-related events (SREs) in metastatic bone disease is discussed. A brief overview on the proposed modes of action is given.

METHODS

Literature search of PubMed documented publications and abstracts from meetings.

RESULTS

Among the biphosphonates currently available, zoledronic acid is the only one known to be capable of delaying SREs in RCC and prostate cancer patients. Zoledronic acid counteracts cancer treatment-induced osteoporosis in men with prostate malignancies. The antitumor activity of biphosphonates found in vitro and in vivo is intriguing and has to be further assessed in clinical studies.

CONCLUSION

Due to its unique properties, zoledronic acid is a breakthrough in the management of metastatic bone disease in patients with advanced prostate cancer and RCC. It significantly improves the patients' quality of life, drastically prolongs time to first SRE, and showed a positive but not significant effect on survival.

Quality of Life in Prostate Cancer Patients Taking Androgen Deprivation Therapy

OBJECTIVES

To examine the effect of androgen deprivation therapy (ADT) on health-related quality of life (HRQOL), self-reported HRQOL was compared in prostate cancer patients receiving short- (< 6 months) or long-term (> or = 6 months) ADT and healthy controls.

DESIGN

Cross-sectional study.

SETTING

Academic medical center in Pittsburgh, Pennsylvania.

PARTICIPANTS

Ninety-six men, including those with prostate cancer receiving short-term, long-term, and no ADT and healthy controls. Men taking medications or having diseases known to affect bone mineral metabolism were excluded.

MEASUREMENTS

The 36-item Short Form Medical Outcomes Study Health Survey (an HRQOL assessment) and a comorbidity index were administered to each participant. Characteristics, including body composition (assessed using dual-energy x-ray absorptiometry) and gonadal status (serum total and free testosterone) were measured approximately 3 months or less before the HRQOL assessment.

RESULTS

As expected, men receiving ADT had significantly lower levels of testosterone, free testosterone, and lean body mass, as well as greater body fat and comorbidity index (all P<.01) than men not receiving ADT (i.e., men with prostate cancer and healthy controls). Participants receiving ADT reported significantly poorer QOL in the areas of physical function (P<.001), general health (P<.001), and physical health component summary (P<.001) than men not receiving ADT. There were no significant differences in HRQOL outcomes between participants receiving short- or long-term ADT. Comorbidity and testosterone levels were associated with several QOL scales. After controlling for the significant joint predictors of comorbidity and total testosterone using hierarchical regression analysis, ADT was no longer a significant predictor, and only comorbidity and total testosterone contributed to the explanation of the variance of the physical health component summary. Comorbidity alone contributed to the explanation of the variance in physical function, bodily pain, general health, and vitality.

CONCLUSION

Patients with prostate cancer who were receiving ADT experience worse HRQOL than those not receiving ADT, but duration of ADT was not a contributing factor. After controlling for comorbidity, total testosterone level rather than ADT accounted for a small yet statistically significant percentage of the total variance of the physical health component summary. These findings have important clinical implications regarding the decision to treat prostate cancer patients with ADT.

Bone loss after initiation of androgen deprivation therapy in patients with prostate cancer

CONTEXT

Although androgen deprivation therapy (ADT) for prostate cancer is associated with bone loss, little is known about when this bone loss occurs.

OBJECTIVE

We postulated that men on ADT would experience the greatest bone loss acutely after initiation of ADT.

DESIGN AND SETTING

We conducted a 12-month prospective study at an academic medical center.

PATIENTS OR OTHER PARTICIPANTS

We studied 152 men with prostate cancer (30 with acute ADT, < 6 months; 50 with chronic ADT, > or = 6 months; and 72 with no ADT) and 43 healthy age-matched controls.

MAIN OUTCOME MEASURES

We assessed bone mineral density (BMD) of the hip, wrist, total body, and spine; body composition; and markers of bone turnover.

RESULTS

After 12 months, men receiving acute ADT had a significant reduction in BMD of 2.5 +/- 0.6% at the total hip, 2.4 +/- 1.0% at the trochanter, 2.6 +/- 0.5% at the total radius, 3.3 +/- 0.5% at the total body, and 4.0 +/- 1.5% at the posteroanterior spine (all P < 0.05). Men with chronic ADT had a 2.0 +/- 0.6% reduction in BMD at the total radius (P < 0.05). Healthy controls and men with prostate cancer not receiving ADT had no significant reduction in BMD. Both use and duration of ADT were associated with change in bone mass at the hip (P < 0.05). Men receiving acute ADT had a 10.4 +/- 1.7% increase in total body fat and a 3.5 +/- 0.5% reduction in total body lean mass at 12 months, whereas body composition did not change in men with prostate cancer on chronic ADT or in healthy controls (P < 0.05). Markers of bone formation and resorption were elevated in men receiving acute ADT after 6 and 12 months compared with the other men with prostate cancer and controls (P < 0.05). Men in the highest tertile of bone turnover markers at 6 months had the greatest loss of bone density at 12 months.

CONCLUSIONS

Men with prostate cancer who are initiating ADT have a 5- to 10-fold increased loss of bone density at multiple skeletal sites compared with either healthy controls or men with prostate cancer who are not on ADT, placing them at increased risk of fracture. Bone loss is maximal in the first year after initiation of ADT, suggesting initiation of early preventive therapy.

Intermittent Androgen Castration: A Biological Reality during Intermittent Treatment in Metastatic Prostate Cancer?

INTRODUCTION

To assess the effects of intermittent maximal androgen blockade (IMAB) on testosterone (T) levels during on- and off-treatment periods.

MATERIALS AND METHODS

A total of 51 patients with metastatic prostate cancer underwent a 6-months period of continuous maximal androgen blockade (MAB) consisting of leuprorelin (3.75 mg at monthly intervals) plus flutamide (250 mg t.i.d.) followed by IMAB. During each cycle, the cut-off prostate-specific antigen (PSA) levels to stop and resume treatment were 4 and 10 ng/ml, respectively. IMAB continued until progression under treatment occurred. Monthly PSA and T measurements were performed in central laboratories.

RESULTS

From the 51 patients included (mean age 67.6 years), 27, 16, 12, 8 and 5 underwent a second, third, fourth, fifth and sixth cycle, respectively (mean follow up: 17 months). Before treatment, 4 patients had a T lower than normal laboratory value but these recovered all to a normal T value at the end of the first cycle. During the 6 cycles, only 8 patients did not recover a normal T at least once during the off-treatment periods (OTP). The mean T values at the end of each OTP did not change during these 6 cycles (Anova test, p=0.621) with a mean stable recovery delay of 32-43 days (Anova test, p=0.722).

CONCLUSION

IMAB protocol with an initial 6-month treatment period can result in an intermittent castration with the recovery of normal T levels in most patients during six consecutive cycles of treatment.

Effect of testosterone replacement on trabecular architecture in hypogonadal men

We evaluated the effect of testosterone treatment on trabecular architecture by microMRI in 10 untreated severely hypogonadal men. After 2 years, microMRI parameters of trabecular connectivity improved significantly, suggesting the possibility that testosterone improves trabecular architecture.

INTRODUCTION

Osteoporosis, characterized by low BMD and diminished bone quality, is a significant public health problem in men. Hypogonadal men have decreased BMD and deteriorated trabecular architecture compared with eugonadal men, and testosterone treatment improves their BMD. We tested the hypothesis that testosterone replacement in hypogonadal men would also improve their trabecular architecture.

MATERIALS AND METHODS

We selected 10 untreated severely hypogonadal men and treated them with a testosterone gel for 24 months to maintain their serum testosterone concentrations within the normal range. Each subject was assessed before and after 6, 12, and 24 months of testosterone treatment by magnetic resonance microimaging (microMRI) of the distal tibia and by DXA of the spine and hip. The microMRI parameters reflect the integrity of the trabecular network and include the ratio of all surface voxels (representing plates) to curve voxels (representing rods) and the topological erosion index, a ratio of topological parameters expected to increase on trabecular deterioration to those expected to decrease. The higher the surface-to-curve ratio and the lower the topological erosion index, the more intact the trabecular network.

RESULTS

Serum testosterone concentrations increased to midnormal after 3 months of treatment and remained normal thereafter. After 24 months of testosterone treatment, BMD of the spine increased 7.4% (p<0.001), and of the total hip increased 3.8% (p=0.008). Architectural parameters assessed by microMRI also changed: the surface-to-curve ratio increased 11% (p=0.004) and the topological erosion index decreased 7.5% (p=0.004).

CONCLUSIONS

These results suggest the possibility that testosterone replacement of hypogonadal men improves trabecular architecture.

Fracture risk in patients with prostate cancer on androgen deprivation therapy

Although a decrease in bone mass is a well-known side effect of hormone therapy for prostate carcinoma, its clinical significance is unclear, as there is only scanty information about the incidence of fractures. Therefore, the aim of this study was to determine the risk of non-metastatic fractures in patients with prostate cancer undergoing androgen deprivation therapy. We performed a retrospective cohort study that comprised 288 patients with cancer who were subjected to androgen deprivation therapy (ADT). All were given LHRH agonists, and most of them also received peripheral androgen receptor blockers. The results were compared with a control group of 300 men that were not receiving ADT. The incidence rates of peripheral and vertebral fractures in the group of men on ADT were 1.9 and 0.8 per 100 patient-years, respectively. Incidence rates in the control group were 0.5 and 0.2, respectively. In the whole study group, 35 patients had at least one fracture during follow-up (25 on ADT, ten controls). Thus, the number of patients with at least one fracture was significantly higher in the group on ADT (P = 0.001 by the log-rank test). The unadjusted risk ratio was 4.2 (CI 2.0-8.9). A similar value (risk ratio 3.6; CI 1.6-7.7, P = 0.001) was found after it was adjusted for other factors, such as age or prior fractures. Therefore, ADT is associated with a fourfold increase in the incidence rate of both peripheral and vertebral fractures. Although the absolute incidence remains relatively small, preventive measures should be considered for high-risk patients.

Preventing and treating the complications of hormone therapy

Hormonal manipulation in the form of androgen-deprivation therapy for prostate cancer was introduced by Huggins and Hodges in 1941 and resulted in a Nobel Prize in 1966. Hormonal therapy initially had been used in metastatic prostate cancer, but the indications have been expanded including failed local therapy, locally advanced prostate cancer, and neoadjuvant or adjuvant therapy in high-risk localized prostate cancer. In view of the magnitude of the problem of prostate cancer and relatively frequent use of hormonal manipulation, it is important for clinicians to be aware of common side effects, prevention, and treatment to improve quality of life and reduce morbidity and mortality in patients with prostate cancer. This review focuses on the common side effects of hormonal treatment such as osteoporosis, anemia, hot flashes, erectile dysfunction, muscle wasting, gynecomastia, decline in cognitive function, depression, increase in body fat and metabolic changes, and their prevention and treatment.

Androgens and bone metabolism

The gradual reductions in bone mass and skeletal calcium density seen throughout adulthood occur in parallel with changes in the production of bioactive sex hormones in both men and women. The long-held belief that osteoporosis is dependent on androgens in men and estrogens in women has been challenged by recent reports of osteoporosis in young men with normal testosterone levels but extremely low estrogen levels. A review of the literature indicates that estrogens have a far greater influence on bone mass than do androgens. This may suggest new approaches to the treatment of male osteoporosis. Furthermore, osteoporosis induced by prostate cancer treatment should receive greater medical attention.

Epidemiology of male osteoporosis and prostate cancer

PURPOSE OF REVIEW

In this review, we will discuss the increasing importance of male osteoporosis, risk factors for the disease, its relationship to prostate cancer and androgen deprivation treatment modalities for prostate cancer, and recent trials describing therapeutic intervention.

RECENT FINDINGS

Osteoporosis has become an increasingly important problem in men's health, accounting for significant morbidity in the aging United States male population. Hypogonadism is a major risk factor. Patients treated with androgen deprivation therapy for advanced or metastatic prostate cancer are at risk for both hypogonadism and osteoporosis. These patients may suffer additional morbidity from decreased bone mineralization, such as skeletal fracture. There is a direct association with fracture and decreased quality of life and increased mortality.

SUMMARY

Male osteoporosis is an important clinical entity, particularly in aging men and in men with prostate cancer treated with androgen deprivation therapy. No screening recommendations currently exist; however, patients at risk for decreased bone mineralization should be screened and treated to prevent consequent fractures.

Skeletal Morbidity in Men with Prostate Cancer: Quality-of-Life Considerations throughout the Continuum of Care

OBJECTIVE

With current treatments, men usually survive many years after being diagnosed with prostate cancer. However, without supportive care, the systemic effects of prostate cancer and therapies such as androgen deprivation therapy (ADT) can undermine skeletal integrity, resulting in skeletal complications that may erode quality of life (QOL). Prostate cancer patients are at risk for fractures from cancer treatment-induced bone loss. In addition, they are also at risk for pathologic fractures, severe bone pain, and other sequelae from bone metastases, which almost invariably occur during the progression of prostate cancer. This review investigates the incidence and pathophysiology of bone loss and skeletal morbidity in prostate cancer patients and reviews available treatment options for maintaining skeletal health throughout the continuum of care for these patients.

METHODS

Studies were identified through MEDLINE searches, review of bibliographies of relevant articles, and review of abstracts from national meetings.

RESULTS

Several supportive care options are available to prevent generalized and localized bone loss, including calcium and vitamin D supplements and bisphosphonates. Oral calcium and vitamin D supplementation alone, however, appears to be insufficient to prevent bone loss during ADT. Zoledronic acid administered every 3 months during ADT or every 3 to 4 weeks for patients with bone metastases can reverse bone loss and reduce skeletal morbidity, respectively, in patients with prostate cancer.

CONCLUSIONS

Skeletal complications contribute to the erosion of QOL in prostate cancer patients. Palliative care can provide important benefits to these patients. Some agents, such as zoledronic acid, may provide skeletal health benefits throughout the course of prostate cancer progression. Further investigations of the QOL impact of these benefits are warranted.

L'ostéoporose masculine: épidémiologie, physiopathologie, diagnostic, prévention et traitement

PURPOSE

This article reviews the most current information about epidemiology, risk factors, diagnosis, prevention and management of male osteoporosis.

MAIN POINTS

Although osteoporosis is often regarded as a disease of women, 30% of osteoporotic fractures occur in men. Risk factors for osteoporosis or fractures in men include previous fragility fractures, maternal history of fragility fracture, hypogonadism, low body mass index, smoking, high alcohol consumption, low calcium intake, corticoid therapy, physical inactivity, and the presence of conditions such as hyperthyroidism, hyperparathyroidism, hypercalciuria or chronic inflammatory diseases. Treatment of osteoporosis is recommended in men aged > 65 years with low bone mass (T-score < -2.5), in men aged 50 to 65 years with low bone mass and at least one risk factor for osteoporosis or fracture, in men aged < 50 years with Z-score < -2 with at least one risk factor for osteoporosis or fracture and in men with at least two fragility fractures.

FUTURE ASPECTS

Further studies are needed to better estimate the benefit of of bisphophonates in the prevention of glucocorticoid-induced osteoporosis and the prevention of androgen-deprivation therapy (treatment of prostate cancer) in men at high-risk for osteoporosis, of parathyroid hormone (1-34) in male primary osteoporosis, and of androgen therapy in men with symptoms (including low bone mineral density) and biological signs (with low blood free testosterone levels) of hypogonadism.

Osteoporosis and spinal fractures in men with prostate cancer: risk factors and effects of androgen deprivation therapy

PURPOSE

We determined the risk factors for osteoporosis and spinal fractures in men with prostate cancer receiving androgen deprivation therapy.

MATERIALS AND METHODS

We performed a retrospective analysis of 87 consecutive men with prostate cancer receiving androgen deprivation therapy referred for evaluation of osteoporosis. Data were comprised of lateral thoracolumbar radiographs, bone densitometry, serum biochemistry and a detailed assessment of osteoporotic risk factors. Multivariate regression analysis was used to determine the major risk factors for osteoporosis and spinal fractures.

RESULTS

There were 38 (44%) men who were 74.5 years old with radiographic evidence of spinal fractures. They had an initial mean prostate specific antigen of 52.8 ng/ml and had received androgen deprivation therapy for a mean of 39.6 months (95% confidence interval 28.7 to 50.4). Mean spinal (quantitative computerized tomography t-score -4.2) and femoral neck bone mineral densities (dual energy x-ray absorptiometry t-score -2.1) were significantly lower than in men without spinal fractures (p < 0.001 for all measurements). In the regression analysis the duration of androgen deprivation therapy (p = 0.002), serum 25-hydroxyvitamin D levels (p = 0.003) and a history of alcohol excess (defined as more than 4 standard drinks daily, p = 0.04) were the main determinants of spinal fractures.

CONCLUSIONS

Prolonged androgen deprivation therapy, low serum 25-hydroxyvitamin D levels and a history of alcohol excess are important risk factors for osteoporosis and spinal fractures in men with prostate cancer.

Effects of gonadotropin-releasing hormone agonists on bone metabolism markers and bone mineral density in patients with prostate cancer

OBJECTIVES

To better understand bone metabolism and predict bone loss in treatment using gonadotropin-releasing hormone agonist for patients with prostate cancer.

METHODS

The changes in bone mineral density and blood levels of bone metabolism markers and the level of pyridinoline cross-linked carboxy-terminal telopeptide of type I collagen, a specific marker of bone resorption, and carboxy-terminal pro-peptide of human type I procollagen, a specific marker of bone formation, were examined in 27 consecutive patients with prostate cancer without bone metastasis.

RESULTS

After 2 years of gonadotropin-releasing hormone treatment, the bone mineral density was significantly lower (median 0.937 g/cm2) than before treatment. Pyridinoline cross-linked carboxy-terminal telopeptide of type I collagen began to increase significantly 6 months after the start of treatment (3.0 to 8.3 ng/mL, median 4.6, at baseline versus 3.4 to 8.2 ng/mL, median 5.2, after 6 months). Carboxy-terminal pro-peptide of human type I procollagen began to show a significant rise 1 year after the start of treatment (from 72.8 to 221.5 ng/mL, median 102.0, at baseline to 82.7 to 293.4 ng/mL, median 132.0, at 1 year).

CONCLUSIONS

Functional coupling between bone resorption and formation was noted, and a decrease in bone mass, even in men, owing to androgen deficiency, was biochemically demonstrated. Fluctuations in these two bone metabolism markers preceded the decrease of bone mineral density. Therefore, these markers might be a predictor of bone loss.

Androgens and bone

Loss of estrogens or androgens increases the rate of bone remodeling by removing restraining effects on osteoblastogenesis and osteoclastogenesis, and also causes a focal imbalance between resorption and formation by prolonging the lifespan of osteoclasts and shortening the lifespan of osteoblasts. Conversely, androgens, as well as estrogens, maintain cancellous bone mass and integrity, regardless of age or sex. Although androgens, via the androgen receptor (AR), and estrogens, via the estrogen receptors (ERs), can exert these effects, their relative contribution remains uncertain. Recent studies suggest that androgen action on cancellous bone depends on (local) aromatization of androgens into estrogens. However, at least in rodents, androgen action on cancellous bone can be directly mediated via AR activation, even in the absence of ERs. Androgens also increase cortical bone size via stimulation of both longitudinal and radial growth. First, androgens, like estrogens, have a biphasic effect on endochondral bone formation: at the start of puberty, sex steroids stimulate endochondral bone formation, whereas they induce epiphyseal closure at the end of puberty. Androgen action on the growth plate is, however, clearly mediated via aromatization in estrogens and interaction with ERalpha. Androgens increase radial growth, whereas estrogens decrease periosteal bone formation. This effect of androgens may be important because bone strength in males seems to be determined by relatively higher periosteal bone formation and, therefore, greater bone dimensions, relative to muscle mass at older age. Experiments in mice again suggest that both the AR and ERalpha pathways are involved in androgen action on radial bone growth. ERbeta may mediate growth-limiting effects of estrogens in the female but does not seem to be involved in the regulation of bone size in males. In conclusion, androgens may protect men against osteoporosis via maintenance of cancellous bone mass and expansion of cortical bone. Such androgen action on bone is mediated by the AR and ERalpha.

Intermittent versus continuous total androgen blockade in the treatment of patients with advanced hormone-naive prostate cancer: results of a prospective randomized multicenter trial

The aim of this study was to compare the efficacy of total intermittent androgen deprivation (IAD) versus total continuous androgen deprivation (CAD) for treating patients with advanced prostate cancer in a phase III randomized trial. A total of 68 evaluable patients with hormone-naive advanced or relapsing prostate cancer were randomized to receive combined androgen blockade according to a continuous (n = 33) or intermittent (n = 35) regimen. Therapeutic monitoring was assessed by use of serum prostate-specific antigen (PSA) measurements. Patients in the CAD and IAD groups were equally stratified for age, biopsy Gleason score, and baseline serum PSA levels. The outcome variable was time to androgen-independence of the tumor, which was defined as increasing serum PSA levels despite androgen blockade. Mean follow-up was 30.8 months. The 35 IAD-treated patients completed 91 cycles, and 19 of them (54.3%) completed > or = 3 cycles. Median cycle length and percentage of time off therapy were 9.0 months and 59.5, respectively. The estimated 3-year progression rate was significantly lower in the IAD group (7.0% +/- 4.8%) than in the CAD group (38.9% +/- 11.2%, P = 0.0052). Our data suggest that IAD treatment may maintain the androgen-dependent state of advanced human prostate cancer, as assessed by PSA measurements, at least as long as CAD treatment. Further studies with longer follow-up times and larger patient cohorts are needed to determine the comparative impacts of CAD and IAD on survival.

Osteoporosis in men with prostate carcinoma receiving androgen-deprivation therapy: recommendations for diagnosis and therapies

BACKGROUND

Androgen-deprivation therapy (ADT) is prescribed with increasing frequency for men with prostate carcinoma. There is growing concern about the effects of such therapy on the skeleton. In the current review, the authors addressed the current research, diagnostic methods, and treatment recommendations for bone loss and osteoporosis in men with prostate carcinoma who received ADT.

METHODS

Data were obtained from electronic literature searches (for the years 1986 through 2002) and from abstracts and meeting proceedings. All randomized and nonrandomized clinical trials, retrospective studies, and cross-sectional studies of osteoporosis in men with prostate carcinoma who received ADT with or without other therapies were reviewed.

RESULTS

The findings confirmed that ADT resulted in significant bone loss in men with prostate carcinoma. Bone mineral density (BMD) of the hip, as measured by dual-energy X-ray absorptiometry (DXA), is considered the preferred site of assessment in older men. Spinal BMD is equally important, although careful interpretation of spinal DXA values is required, because of coexisting facet joint disease and extravertebral calcification. Osteoporosis is diagnosed when BMD is > 2.5 standard deviations below a reference mean. Men with prostate carcinoma who were treated with ADT had average BMD measurements below those of eugonadal men. Rates of bone loss ranged from 2% to 8% in the lumbar spine and from 1.8% to 6.5% in the femoral neck during the initial 12 months of continuous ADT. Retrospective data indicated an increased risk of fracture in men with prostate carcinoma who were treated with ADT.

CONCLUSIONS

For men with prostate carcinoma who are at high risk for osteoporosis and fractures, clinical management should be dictated by the results of radiographic and DXA skeletal assessment.

Exploring the effects of luteinizing hormone-releasing hormone agonist therapy on bone health: implications in the management of prostate cancer

Osteoporosis is a complication that may be associated with long-term androgen deprivation therapy (ADT) in men with prostate cancer. Androgen deprivation increases bone resorption, thereby leading to a more rapid decrease of bone mineral density (BMD) at multiple skeletal sites as compared with age-matched healthy men. ADT has been associated with an increased risk of skeletal fracture in several retrospective analyses. The role of androgens in maintaining bone health appears to be mediated indirectly through their conversion to estrogens, although testosterone may be an important factor in bone formation. Physicians need to be aware of the potential for osteoporosis and should inform patients of appropriate lifestyle and diet modifications, such as calcium and vitamin D supplementation, and exercise at the initiation of ADT. Evaluating BMD may become the accepted norm. Several studies suggest that bisphosphonates may be beneficial in preventing and treating osteoporosis in patients with prostate cancer. The overall benefit of ADT in men with prostate cancer will continue to improve as potential side effects, such as osteoporosis, are recognized and addressed successfully.

Management of Bone Loss in Men With Prostate Cancer

PURPOSE

Bone loss is increasingly recognized as a common occurrence in men receiving androgen deprivation therapy (ADT) for prostate cancer. Skeletal metabolism and osteoporosis in men, assessment of bone mineral density (BMD), effects of ADT on BMD, management strategies and potential therapies for osteopenia or osteoporosis in men with prostate cancer are reviewed.

MATERIALS AND METHODS

Relevant literature is reviewed concerning bone loss and osteoporosis in men with and without prostate cancer, techniques of assessing BMD, data on bone loss and fracture risk and management strategies.

RESULTS

The incidence of osteoporotic fractures usually increases a decade later in men than in women. ADT causes significant loss of BMD, which may hasten the development of osteoporosis. Men who are treated with hormonal therapy for an increasing prostate specific antigen and who may live for many years should have baseline BMD assessments. Osteopenia or osteoporosis should be treated to minimize the risk of osteoporotic fracture. Treatment with zoledronic acid seems appropriate since it has been shown to increase BMD in men treated with ADT and to reduce the rate of skeletal related events in men with early hormone refractory prostate cancer with metastatic disease.

CONCLUSIONS

Monitoring BMD is warranted in men contemplating or receiving ADT but prophylactic therapy to prevent bone loss currently is not recommended. Men with evidence of significant bone loss who are receiving ADT should be treated. Zoledronic acid is a logical choice based on available data.

The effects of combined androgen blockade on cognitive function during the first cycle of intermittent androgen suppression in patients with prostate cancer

PURPOSE

Men with prostate specific antigen (PSA) only relapse of prostate cancer after primary therapy are generally fully functional and asymptomatic with a life expectancy of up to 10 or more years. These patients are often treated with androgen suppression. We evaluate the effects of androgen suppression on cognitive function.

MATERIALS AND METHODS

Hormone naïve patients without evidence of metastases with an increasing PSA were treated with intermittent androgen suppression consisting of 9 months of leuprolide and flutamide followed by an off treatment period determined by the increase in PSA. Cognitive function tests were administered at baseline, after 9 months of androgen suppression and after 3 months off treatment. Cognitive tests measured spatial abilities, spatial memory, verbal fluency, verbal memory and selective attention. A total of 19 patients 52 to 76 years old completed the intermittent androgen suppression study along with 15 healthy community dwelling control participants.

RESULTS

Combined androgen blockade reduced PSA and testosterone in all patients compared to baseline. Patients did not significantly change on measures of verbal and spatial memory, executive functions or language. Patients declined on a measure of spatial rotation and improved on a measure of verbal memory during treatment which continued during the off treatment period.

CONCLUSIONS

Although preliminary, these findings demonstrate that 9 months of combined androgen blockade resulted in a beneficial effect on verbal memory but adversely affected a measure of spatial ability. Intermittent androgen suppression for a period of 9 months in otherwise healthy men with prostate cancer may have beneficial and adverse effects on cognition that are selective.