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

Hormone-Related and Drug-Induced Osteoporosis: A Cellular and Molecular Overview

Osteoporosis resulting from an imbalance of bone turnover between resorption and formation is a critical health issue worldwide. Estrogen deficiency following a nature aging process is the leading cause of hormone-related osteoporosis for postmenopausal women, while glucocorticoid-induced osteoporosis remains the most common in drug-induced osteoporosis. Other medications and medical conditions related to secondary osteoporosis include proton pump inhibitors, hypogonadism, selective serotonin receptor inhibitors, chemotherapies, and medroxyprogesterone acetate. This review is a summary of the cellular and molecular mechanisms of bone turnover, the pathophysiology of osteoporosis, and their treatment. Nuclear factor-κβ ligand (RANKL) appears to be the critical uncoupling factor that enhances osteoclastogenesis. In contrast, osteoprotegerin (OPG) is a RANKL antagonist secreted by osteoblast lineage cells. Estrogen promotes apoptosis of osteoclasts and inhibits osteoclastogenesis by stimulating the production of OPG and reducing osteoclast differentiation after suppression of IL-1 and TNF, and subsequent M-CSF, RANKL, and IL-6 release. It can also activate the Wnt signaling pathway to increase osteogenesis, and upregulate BMP signaling to promote mesenchymal stem cell differentiation from pre-osteoblasts to osteoblasts rather than adipocytes. Estrogen deficiency leads to the uncoupling of bone resorption and formation; therefore, resulting in greater bone loss. Excessive glucocorticoids increase PPAR-2 production, upregulate the expression of Dickkopf-1 (DKK1) in osteoblasts, and inhibit the Wnt signaling pathway, thus decreasing osteoblast differentiation. They promote osteoclast survival by enhancing RANKL expression and inhibiting OPG expression. Appropriate estrogen supplement and avoiding excessive glucocorticoid use are deemed the primary treatment for hormone-related and glucocorticoid-induced osteoporosis. Additionally, current pharmacological treatment includes bisphosphonates, teriparatide (PTH), and RANKL inhibitors (such as denosumab). However, many detailed cellular and molecular mechanisms underlying osteoporosis seem complicated and unexplored and warrant further investigation.

Drugs Causing Bone Loss

Drugs may cause bone loss by lowering sex steroid levels (e.g., aromatase inhibitors in breast cancer, GnRH agonists in prostate cancer, or depot medroxyprogestone acetate - DMPA), interfere with vitamin D levels (liver inducing anti-epileptic drugs), or directly by toxic effects on bone cells (chemotherapy, phenytoin, or thiazolidinedions, which diverts mesenchymal stem cells from forming osteoblasts to forming adipocytes). However, besides effects on the mineralized matrix, interactions with collagen and other parts of the unmineralized matrix may decrease bone biomechanical competence in a manner that may not correlate with bone mineral density (BMD) measured by dual energy absorptiometry (DXA).Some drugs and drug classes may decrease BMD like the thiazolidinediones and consequently increase fracture risk. Other drugs such as glucocorticoids may decrease BMD, and thus increase fracture risk. However, glucocorticoids may also interfere with the unmineralized matrix leading to an increase in fracture risk, not mirrored in BMD changes. Some drugs such as selective serotonin reuptake inhibitors (SSRI), paracetamol, and non-steroidal anti-inflammatory drugs (NSAIDs) may not per se be associated with bone loss, but fracture risk may be increased, possibly stemming from an increased risk of falls stemming from effects on postural balance mediated by effects on the central nervous system or cardiovascular system.This paper performs a systematic review of drugs inducing bone loss or associated with fracture risk. The chapter is organized by the Anatomical Therapeutic Chemical (ATC) classification.

Decrease of bone mineral density in Japanese patients with non-metastatic prostate cancer treated with androgen deprivation therapy

The aim of this study was to conduct a cross-sectional survey of investigations related to the bone mineral density (BMD) of both non-metastatic prostate cancer (NMPC) patients who have not yet received androgen deprivation therapy (ADT) and patients receiving prolonged ADT in Japan. Japanese male patients with NMPC who received continuous ADT or who were planning to receive ADT were enrolled in this study. Lumbar spine and femoral neck BMD was measured using dual-energy X-ray absorptiometry (DEXA). To assess patient characteristics, we searched medical records and questionnaires to determine whether they had any factors that could possibly affect BMD. A total of 230 patients with a mean age of 76.6 ± 6.4 years were evaluated. Of these, 151 (65.7%) were receiving ADT, and 79 (34.4%) had not yet received ADT. The mean duration of ADT was 37.4 ± 30.7 months. DEXA showed that as the duration of ADT increased, lumbar spine and femoral neck BMD decreased gradually (p = 0.0005 and p = 0.0014, respectively). Stepwise regression analyses revealed that the duration of ADT was a significant variable of both lumbar spine and femoral neck BMD. Moreover, as the duration of ADT increased, the prevalence of osteoporosis increased statistically (p = 0.0002). This study showed that ADT negatively affected lumbar spine and femoral neck BMD. It also showed a progressive increase in the prevalence of osteoporosis in Japanese NMPC patients with ADT.

Effect of Androgen-deprivation Therapy on Bone Mineral Density in Japanese Patients with Prostate Cancer

BACKGROUND/AIM

To evaluate bone mineral density (BMD) in Japanese patients with prostate cancer (PCa) after administering androgen deprivation therapy (ADT) for 2 years.

PATIENTS AND METHODS

A total of 84 Japanese patients with PCa were enrolled in this study during the period 2008-2011. BMD was measured by dual energy X-ray absorptiometry, every 6 months. The fracture risk assessment tool (FRAX) score was calculated before starting ADT. We evaluated the change in BMD over a 2-year period and the relationship between this change, the FRAX score, and the estimated glomerular filtration rate (eGFR).

RESULTS

Compared to baseline, BMD decreased by 2.50% at 6 months after ADT, by 4.28% after 12 months, by 5.34% after 18 months, and by 6.16% after 2 years (all p<0.05). Multivariate analysis revealed that the eGFR, according to a threshold rate of 73.5 ml/min, was a significant factor in BMD.

CONCLUSION

Lumbar BMD in Japanese patients with PCa decreased by 4.28% at 1 year after ADT and by 6.16% after 2 years. We found a correlation between the decrease in BMD and the eGFR before initiating ADT, suggesting a small BMD reduction in patients with PCa who have good renal function.

Metabolic changes in patients with prostate cancer during androgen deprivation therapy

Androgen deprivation therapy continues to be widely used for the treatment of prostate cancer despite the appearance of new-generation androgen-receptor targeting drugs after 2000. Androgen deprivation therapy can alleviate symptoms in patients with metastatic prostate cancer and might have a survival benefit in some patients, but it causes undesirable changes in lipid, glucose, muscle or bone metabolism. These metabolic changes could lead to new onset or worsening of diseases, such as obesity, metabolic syndrome, diabetes mellitus, cardiovascular disease, sarcopenia or fracture. Several studies examining the influence of androgen deprivation therapy in Japanese patients with prostate cancer also showed that metabolic changes, such as weight gain, dyslipidemia or fat accumulation, can occur as in patients in Western countries. Efforts to decrease these unfavorable changes and events are important. First, overuse of androgen deprivation therapy for localized or elderly prostate cancer patients should be reconsidered. Second, intermittent androgen deprivation therapy might be beneficial for selected patients who suffer from impaired quality of life as a result of continuous androgen deprivation therapy. Third, education and instruction, such as diet or exercise, to decrease metabolic changes before initiating androgen deprivation therapy is important, because metabolic changes are likely to occur in the early androgen deprivation therapy period. Fourth, routine monitoring of weight, laboratory data or bone mineral density during androgen deprivation therapy are required to avoid unfavorable events.

Androgen deprivation in prostate cancer and the long-term risk of fracture

OBJECTIVES

To determine the rate of bone mass loss and the risk of fracture induced by androgen deprivation therapy in patients with prostate cancer.

MATERIAL AND METHODS

Prospective study in 2 phases. In the first phase, demographic variables, FRAX^®, bone mineral density and clinical fractures were collected, before starting the therapy and up to 1 year after ending the therapy. In the second phase, we conducted a telephone interview a mean of 8.5 years after the start of the study to assess new fractures.

RESULTS

We included 150 patients with a mean age of 67 years and a mean therapy duration of 24 months. Before starting the treatment, 62 patients (41%) showed osteoporosis or low bone mass in the densitometry. After the first year of treatment, the bone mineral density decreased a mean of 3.7% and 2.1% in the lumbar spine and femoral neck, respectively. At the end of the second and third year, the loss rate was lower. During the first phase of the study, 4 patients (2.7%) experienced a fracture. In the telephone interviews with 80 patients (53%), only 1 had experienced a fracture.

CONCLUSIONS

In the patients with prostate cancer and androgen deprivation therapy, greater bone loss occurred during the first year. When the treatment did not exceed 2 years, the absolute risk of fracture was low, and clinical fractures were uncommon in the short and long term.

Importance of bone assessment and prevention of osteoporotic fracture in patients with prostate cancer in the gonadotropic hormone analogues use

The antiandrogenic therapy (ADT) for prostate cancer represents an additional risk factor for the development of osteoporosis and fragility fractures. Still, bone health of patients on ADT is often not evaluated. After literature research we found that simple preventive measures can prevent bone loss in these patients, resulting in more cost-effective solutions to the public health system and family when compared to the treatment of fractures.

Clinical usefulness of bone markers in prostate cancer with bone metastasis

Bone metastases occur in approximately 70% of patients with advanced prostate cancer. Skeletal-related events have been correlated with reduced survival and quality of life of patients with prostate cancer. Biochemical markers of bone metabolism (e.g. bone formation, bone resorption, osteoclastogenesis) might meet an unmet need for useful, non-invasive and sensitive surrogate information for following patients' skeletal health. Recently, zoledronic acid and denosumab have been proven to have the potential for preventing skeletal-related events among prostate cancer patients with bone metastasis. An improved understanding of the mechanisms underlying bone metastasis has also led to the recognition of multiple molecular targets and advances in therapy. However, estimating the efficacy of these agents is difficult. A clinical trial for castration-resistant prostate cancer is currently underway based on the definition of The Prostate Cancer Clinical Trials Working Group, and bone turnover markers are being used as conventional end-points for the clinical trial. Bone turnover markers are useful surrogate markers reflecting the effect of new therapeutic drugs and prognosis, as well as assessment of bone metastases. In particular, N-terminal cross-linked telopeptide of type 1 collagen and bone-specific alkaline phosphatase are widely used bone metabolism markers, and offer reliable surrogate markers to detect bone metastatic spread and to predict prognosis for prostate cancer patients with bone metastases.

Osteoporosis piece of multi-morbidity puzzle in geriatric care

Osteoporosis frequently coexists with other chronic diseases and syndromes of aging, and therefore multimorbidity interactions can potentially complicate its evaluation and treatment. This article reviews osteoporosis comorbidity interactions with select common diseases of aging including cardiovascular, neurologic, and geriatric syndromes, and select commonly used medications by older adults. Using depression as a case example, we describe the complex relationship between osteoporosis, mood, and antidepressant medications, and the implications of these interactions for patients and clinicians.

Aging and osteoporosis in breast and prostate cancer

As people with cancer survive longer, and as the US population ages, skeletal effects of cancer treatment are becoming more pronounced. This is particularly true for breast and prostate cancer survivors because of the high average age of patients with these malignancies, the propensity of older adults in general toward the development of osteoporosis, and the wide use of therapeutic agents in these cancers that negatively impact bone health. Various therapies used in the treatment and prevention of cancer may cause decreases in bone mineral density and an increased risk of debilitating fracture, even in the absence of bone metastases. Aging is both a baseline risk factor in the development of osteoporosis and bony fracture, as well as a predictor of poor outcome after fracture. A variety of mechanisms may be responsible for the development of bone loss in patients with breast or prostate cancer. Cytotoxic chemotherapy may directly exert long-term toxic effects on bone. Chemotherapy and endocrine therapy can induce hypogonadism, leading to an increased rate of bone loss. The risk of skeletal events in older adults due to cancer therapy should be appreciated by all oncologists, geriatricians, and internists. The following review may serve as a guide to the skeletal side effects of cancer therapy in older adults with breast or prostate cancer, how to screen for treatment-related bone loss, and how to best prevent and/or treat skeletal events.

Serum N-Terminal Propeptide of Collagen Type I is Associated with the Number of Bone Metastases in Breast and Prostate Cancer and Correlates to Other Bone Related Markers

Background

A number of biomarkers have been proven potentially useful for their ability to indicate bone metastases (BM) in cancer patients. The aim of this study was to investigate the relative utility of a newly developed N-terminal propeptide of collagen type I (PINP) human serum assay for the detection of BM in cancer patients. This assay has a corresponding rat PINP assay which in the future might help in translational science between rodent and human trials.

Methods

Participants were 161 prostate, lung and breast cancer patients stratified by number of BM (Soloway score). PINP was assessed and correlated to number of BM. Additionally, the PINP marker was correlated to bone resorption of young (ALPHA CTX-I)- and aged bone (BETA CTX-I); number of osteoclasts (Tartrate-resistant acid phosphatase 5b, TRACP5B) and osteoclast activity (CTX-I/ TRACP5B).

Results

PINP was significantly elevated in breast- and prostate cancer patients +BM, compared to −BM (P < 0.001), however not in lung cancer patients. A strong linear association was seen between PINP and the number of BMs. Significant elevation of PINP was observed at Soloway scores 1–4 (<0 BM) compared with score 0 (0 BM) (P < 0.001). The correlation between bone resorption of young bone or aged bone and bone formation was highly significant in patients +BM and −BM (P < 0.0001).

Conclusions

Data suggest that the present PINP potentially could determine skeletal involvement in patients with breast or prostate cancer. Correlations suggested that coupling between bone resorption and bone formation was maintained in breast- and prostate cancer patients.

Emerging drugs for the management of cancer treatment induced bone loss

AREAS COVERED IN THIS REVIEW

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

IMPORTANCE OF THE FIELD

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

WHAT THE READER WILL GAIN

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

TAKE HOME MESSAGE

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

Efficacy and safety of leuprorelin in patients with spinal and bulbar muscular atrophy (JASMITT study): a multicentre, randomised, double-blind, placebo-controlled trial

BACKGROUND

Spinal and bulbar muscular atrophy is a hereditary motor neuron disease caused by the expansion of a polyglutamine tract in the androgen receptor. At present there are no treatments for spinal and bulbar muscular atrophy, although leuprorelin suppressed the accumulation of pathogenic androgen receptors in a phase 2 trial. We aimed to assess the efficacy and safety of leuprorelin for spinal and bulbar muscular atrophy.

METHODS

The Japan SBMA Interventional Trial for TAP-144-SR (JASMITT) was a 48-week, randomised, double-blind, placebo-controlled trial done at 14 hospitals between August, 2006, and March, 2008. Patients with spinal and bulbar muscular atrophy were randomly assigned (1:1) by minimisation to subcutaneous 11.25 mg leuprorelin or identical placebo every 12 weeks. Patients and investigators were masked to treatment allocation. The primary endpoint was pharyngeal barium residue, which indicates incomplete bolus clearance, measured at week 48 by videofluorography. All patients who were randomly assigned and who were assessed with videofluorography at least once were included in the analyses. This study is registered with the JMACCT clinical trials registry, number JMA-IIA00009, and the UMIN clinical trials registry, number UMIN000000465.

FINDINGS

204 patients were randomly assigned and 199 started treatment: 100 with leuprorelin and 99 with placebo. At week 48, the pharyngeal barium residue after initial swallowing had changed by -5.1% (SD 21.0) in the leuprorelin group and by 0.2% (18.2) in the placebo group (difference between groups -5.3%; 95% CI -10.8 to 0.3; p=0.063). The mean difference in pharyngeal barium residue after piecemeal deglutition at week 48 was -3.2% (-6.4 to 0.0; p=0.049), but there was no significant difference between the groups after covariate adjustment for the baseline data (-4.1 to 1.6; p=0.392). In a predefined subgroup analysis, leuprorelin treatment was associated with a greater reduction in barium residue after initial swallowing than was placebo in patients with a disease duration less than 10 years (difference between groups -9.8, -17.1 to -2.5; p=0.009). There were no significant differences in the number of drug-related adverse events between groups (57 of 100 in the leuprorelin group and 54 of 99 in the placebo group; p=0.727).

INTERPRETATION

48 weeks of treatment with leuprorelin did not show significant effects on swallowing function in patients with spinal and bulbar muscular atrophy, although it was well tolerated. Disease duration might influence the efficacy of leuprorelin and thus further clinical trials with sensitive outcome measures should be done in subpopulations of patients.

FUNDING

Large Scale Clinical Trial Network Project, Japan and Takeda Pharmaceuticals.

Implications of serum bone turnover markers in prostate cancer patients with bone metastasis

OBJECTIVES

To assess the diagnostic accuracy of serum bone turnover markers for detection of bone metastasis in patients with prostate cancer (PCa) and to assess the usefulness of these markers as predictors of mortality from PCa.

METHODS

Serum total alkaline phosphatase, bone-specific alkaline phosphatase, carboxy-terminal pyridinoline cross-linked telopeptide parts of type-I collagen (1CTP), tartrate-resistant acid phosphatase type 5 b, and prostate-specific antigen (PSA) levels were measured in 222 patients (58 with bone metastasis, 57 with T2M0 PCa, 55 with T3M0 PCa, and 52 without PCa). Multivariate stepwise logistic regression analysis was used to identify independent predictors of bone metastasis. Correlation of serum marker levels with bone metastasis was assessed using receiver operating characteristics analysis. Multivariate Cox proportional hazards analysis was used to predict cause-specific survival in PCa patients with bone metastasis.

RESULTS

Serum total alkaline phosphatase, bone-specific alkaline phosphatase, 1CTP, tartrate-resistant acid phosphatase type 5 b, and PSA levels were significantly elevated in patients with bone metastasis, and correlated significantly with the extent of disease on bone scintigraphy. Multivariate stepwise logistic regression analysis demonstrated that serum PSA and 1CTP were significant predictors of bone metastasis. Receiver operating characteristics analyses showed that serum 1CTP level was the most reliable predictor of bone metastasis (area under the curve = 0.85). Multivariate Cox proportional hazards analysis revealed that only serum 1CTP was an independent prognostic factor for PCa-related death.

CONCLUSIONS

Serum 1CTP level was a more reliable marker than the others to detect bone metastatic spread and to predict survival probability in PCa patients with bone metastasis.

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.

Management of decreased bone mineral density in men starting androgen-deprivation therapy for prostate cancer

OBJECTIVE

To determine whether clinicians discuss bone-specific side-effects with patients on androgen-deprivation therapy (ADT) for prostate cancer, or prescribe lifestyle and pharmacological interventions for low bone mineral density (BMD), as decreased BMD is a common side-effect of ADT, leading to increased risk of fracture.

PATIENTS AND METHODS

Sixty-six men (mean age 70.6 years) with non-metastatic prostate cancer and starting continuous ADT were enrolled in a prospective longitudinal study. BMD was determined by dual X-ray absorptiometry (DXA) at baseline. Patients were interviewed to obtain their medical histories, and charts were reviewed to determine whether clinicians documented potential bone side-effects in clinic notes, and made lifestyle and/or medication recommendations. Both were done at the start of ADT, and 3 and 6 months later. Patients were classified based on DXA T-score as having normal BMD, as osteopenic, or osteoporotic.

RESULTS

At baseline, 53% of patients had osteopenia and 5% had osteoporosis. Within 6 months of starting ADT, general side-effects and bone-specific side-effects of ADT were documented as being discussed with 26% and 15%, respectively. Clinicians recommended lifestyle interventions to 11% of patients. Pharmacological interventions (calcium, vitamin D, and/or bisphosphonates) were recommended to 18% of all patients within 6 months of starting ADT, and to 26% and 67% of osteopenic and osteoporotic patients, respectively.

CONCLUSIONS

A minority of patients is being informed of bone-specific side-effects of ADT. Lifestyle and drug interventions to prevent declines in BMD were recommended uncommonly. Practices around bone health for men starting ADT are suboptimal.

Changes of biochemical markers of bone turnover and YKL-40 following hormonal treatment for metastatic prostate cancer are related to survival

PURPOSE

Elevated serum levels of biochemical markers of bone turnover and YKL-40 in patients with metastatic prostate cancer (PC) at the time of diagnosis are associated to poor prognosis. In this study, we evaluated the value of these biomarkers in monitoring the patients during hormonal treatment.

EXPERIMENTAL DESIGN

Serum procollagen type I N-terminal propeptide (PINP), bone-specific alkaline phosphatase (BAP), CTX-I, and YKL-40 were determined by ELISA in a longitudinal study of 106 patients with metastatic PC during treatment with total androgen ablation or parenteral estrogen. Serum samples were collected with 3 months interval. Median observation time was 4.9 years (range, 3.6-6.2). A total of 78 patients died (64 within 7 months following the last blood sampling).

RESULTS

After 6 months treatment, serum PINP, BAP, and YKL-40 decreased (P < 0.0001), but not serum CTX-I compared with baseline values. Univariate Cox analysis showed that serum PINP at 6 months [log transformed and treated as a continuous variable; hazard ratio (HR), 2.2; P < 0.0001], serum BAP (HR, 1.8; P < 0.0001), and serum CTX-I (HR, 2.4; P < 0.0001), but not serum YKL-40 (HR, 1.4; P = 0.16) were associated with survival. Multivariate Cox analysis including the biomarkers 6 months after the start of treatment showed that Soloway score (HR, 3.9; P = 0.013), WHO tumor grade (HR, 3.9; P = 0.004), and serum PINP (HR, 2.2; P < 0.0001) were independent prognostic variables of survival. Scoring the biomarkers during treatment as time-dependent covariates in univariate Cox regression analysis showed that increases in serum PINP (HR, 2.0; P < 0.0001), BAP (HR, 2.1; P < 0.0001), and YKL-40 (HR, 2.1; P < 0.0001) were predictors of early death.

CONCLUSIONS

Serial monitoring of serum PINP, BAP, CTX-I, and YKL-40 in metastatic PC patients during hormonal treatment provided information of prognosis.

Serum bone turnover markers (PINP and ICTP) for the early detection of bone metastases in patients with prostate cancer: a longitudinal approach

PURPOSE

An increase in bone turnover markers in patients with prostate cancer may predict bone metastases but it can also reflect the effects of androgen deprivation treatment. To assess the diagnostic efficacy of early detection of skeletal metastases we retrospectively performed serial measurements of a bone formation marker (PINP) and a bone resorption marker (ICTP) in serum of patients with prostate cancer.

MATERIALS AND METHODS

Residual serum samples from 64 patients with prostate cancer treated between 1999 and 2004 were selected from our prostate specific antigen serum archive, and divided into 3 groups of patients with no metastases (N0M0), with lymph node metastases only (N1M0) and with skeletal metastases (M1). In the M1 group the T(1) sample was collected near the first positive bone scintigraph.

RESULTS

The N1M0 and M1 groups showed increased PINP levels (ANOVA T(0) p = 0.035, T(1) p <0.001). The PINP levels in the M1 group increased further (paired t test p = 0.028), while no increase was found in the other groups. There was no significant difference between the number of patients receiving androgen deprivation therapy in the N1M0 and the M1 groups. Increased PINP levels in the M1 group were detectable 8 months before the first positive bone scintigraph. The increase in ICTP in the M1 group differed significantly from the other groups (the Student t test in 45 patients p = 0.029). The increases in PINP and ICTP differentiated between patients with or without skeletal metastases (AUC 0.71, p = 0.002 and AUC 0.64, p = 0.045, respectively).

CONCLUSIONS

Followup measurement of serum PINP and ICTP is useful in the early assessment of skeletal metastases in patients with prostate cancer regardless of the confounding role of androgen deprivation treatment. The bone formation marker is the most indicative.

Abarelix for injectable suspension: first-in-class gonadotropin-releasing hormone antagonist for prostate cancer

Abarelix, a gonadotropin-releasing hormone antagonist, with its indication for advanced symptomatic prostate cancer, represents the newest category of hormonal therapy introduced in the past 15 years. Results from Phase II and III clinical trials demonstrate the advantages of abarelix over commonly used luteinizing hormone-releasing hormone (LHRH) agonist therapy: abarelix does not cause a surge in serum testosterone that can precipitate a flare phenomenon or worsening of disease, particularly dangerous for patients with metastatic, symptomatic disease, and produces medical castration more quickly. Abarelix was also demonstrated to promptly and substantially reduce follicle-stimulating hormone levels to lower than LHRH agonist. Study results demonstrate effective anticancer responses during extended exposure to abarelix: improvements in pain score and/or analgesic use, improvements in urinary symptoms (including urinary catheter removal) and complete avoidance of bilateral orchiectomy for patients undergoing at least 12 weeks of treatment. In Phase III clinical trials, abarelix demonstrated a similar overall safety profile when compared with LHRH agonist monotherapy, and a superior safety profile when compared with LHRH agonist plus antiandrogen combination therapy. Abarelix patients experienced a greater incidence of immediate-onset systemic allergic reactions as compared with control arms.

High dose estrogen treatment increases bone mineral density in male-to-female transsexuals receiving gonadotropin-releasing hormone agonist in the absence of testosterone

OBJECTIVE

To study the effect of estrogen (E) on the male skeleton in the absence of testosterone (T).

DESIGN

Retrospective analyses of 40 middle-aged transsexuals treated with subcutaneous injections of gonadotropin-releasing hormone agonist every 4 weeks and oral 17-beta-estradiol-valerat 6 mg/day over two years until reassignment surgery.

METHODS

The bone mineral density (BMD) in the femoral neck and lumbar spine (L2-L4) was measured with dual-energy X-ray absorptiometry at the beginning of cross-sex hormone treatment, after 12 and 24 months, and serum T, E, sex hormone-binding globulin (SHBG), calcitonin (CAL), osteocalcin (OSC), and urinary free deoxypyridinoline (DPD) were measured.

RESULTS

After 12 months, a significant increase in BMD in the lumbar spine from 1.2 to 1.234 g/cm2 and after 24 months to 1.274 g/cm2 was observed. There was a significant increase in BMD in the femoral neck area from 1.068 to 1.109 g/cm(2) after 24 months. There was a significant decrease in serum T levels from 18.65 to 0.57 nmol/l after 12 months, and to 0.62 nmol/l after 24 months, a significant increase in SHBG levels from 50.09 to 125 nmol/l after 12 months, and to 130 nmol/l after 24 months, and a significant increase in serum E levels from 73.42 to 881.6 pmol/l after 12 months, and to 923.62 pmol/l after 24 months of cross-sex hormone treatment. Serum levels of CAL, OSC and urinary DPD were unchanged.

CONCLUSION

We conclude that high dose E treatment is able to increase BMD significantly in the femoral neck and lumbar spine independently of serum T levels in middle-aged men. There is no risk of osteoporosis developing in male-to-female transsexuals receiving GnRHa when there is an adequate E substitution.