The effect of combined androgen blockade on bone turnover and bone mineral density in men with prostate cancer

Changes in bone and mineral homeostasis after short-term androgen deprivation therapy with or without androgen receptor signalling inhibitor - substudy of a single-centre, double blind, randomised, placebo-controlled phase 2 trial

BACKGROUND

Prostate cancer (PCa) patients treated with androgen deprivation therapy (ADT) have an increased fracture risk. Exploring biomarkers for early bone loss detection is of great interest.

METHODS

Pre-planned substudy of the ARNEO-trial (NCT03080116): a double blind, randomised, placebo-controlled phase 2 trial performed in high-risk PCa patients without bone metastases between March 2019 and April 2021. Patients were 1:1 randomised to treatment with gonadotropin-releasing hormone antagonist (degarelix) + androgen receptor signalling inhibitor (ARSI; apalutamide) versus degarelix + matching placebo for 12 weeks prior to prostatectomy. Before and following ADT, serum and 24-h urinary samples were collected. Primary endpoints were changes in calcium-phosphate homeostasis and bone biomarkers.

FINDINGS

Of the 89 randomised patients, 43 in the degarelix + apalutamide and 44 patients in the degarelix + placebo group were included in this substudy. Serum corrected calcium levels increased similarly in both treatment arms (mean difference +0.04 mmol/L, 95% confidence interval, 0.02; 0.06), and parathyroid hormone and 1,25-dihydroxyvitamin D3 levels decreased. Bone resorption markers increased, and stable calcium isotope ratios reflecting net bone mineral balance decreased in serum and urine similarly in both groups.

INTERPRETATION

This exploratory substudy suggests that 12 weeks of ADT in non-metastatic PCa patients results in early bone loss. Additional treatment with ARSI does not seem to more negatively influence bone loss in the early phase. Future studies should address if these early biomarkers are able to predict fracture risk, and can be implemented in clinical practice for follow-up of bone health in PCa patients under ADT.

FUNDING

Research Foundation Flanders; KU Leuven; University-Hospitals-Leuven.

Surgical Tolerability and Frailty in Elderly Patients Undergoing Robot-Assisted Radical Prostatectomy: A Narrative Review

Simple Summary

Life expectancy in Western countries and East Asian countries has incremented over the past decades, resulting in a rapidly aging world, while in general, radical prostatectomy (RP) is not recommended in elderly men aged ≥75 years. Together with the evolving technique of robotic surgeries, surgical indications for RP should be reconsidered in ‘elderly’ and ‘frail’ men, since this procedure has now become one of the safest and most effective cancer treatments for prostate cancer. One important element to determine surgical indications is surgical tolerability. However, evidence is scarce regarding the surgical tolerability in elderly men undergoing robot-assisted radical prostatectomy (RARP). In this review, we focused on the surgical tolerability in ‘elderly’ and/or ‘frail’ men undergoing RARP, with the intent to provide up-to-date information on this matter and to support the decision making of therapeutic options in this spectrum of patients.

Abstract

Robot-assisted radical prostatectomy (RARP) has now become the gold standard treatment for localized prostate cancer. There are multiple elements in decision making for the treatment of prostate cancer. One of the important elements is life expectancy, which the current guidelines recommend as an indicator for choosing treatment options. However, determination of life expectancy can be complicated and difficult in some cases. In addition, surgical tolerability is also an important issue. Since frailty may be a major concern, it may be logical to use geriatric assessment tools to discriminate ‘surgically fit’ patients from unfit patients. Landmark studies show two valid models such as the phenotype model and the cumulative deficit model that allow for the diagnosis of frailty. Many studies have also developed geriatric screening tools such as VES-13 and G8. These tools may have the potential to directly sort out unfit patients for surgery preoperatively.

Effect of Androgen Deprivation Therapy on Bone Mineral Density in a Prostate Cancer Cohort in New Zealand: A Pilot Study

Introduction:

Reduction in bone mineral density (BMD) is a common side effect of androgen deprivation therapy (ADT). We aimed to examine the cross-sectional and longitudinal variation in BMD and associated bone markers in patients with nonmetastatic prostate cancer (PCa) managed with and without ADT.

Methods:

Bone mineral density of the total body, lumbar spine, femoral neck, ultradistal forearm, and one-third distal radius was measured in 88 patients with PCa without bone metastases at baseline and at 6 months. Patients were categorized into 4 groups: (1) acute ADT (≤6 months), (2) chronic ADT (>6 months), (3) former ADT, and (4) no ADT (controls). Serum levels of bone metabolism markers, procollagen type I N-terminal propeptide (PINP) and C-terminal cross-linking telopeptide of type I collagen (CTX), were also measured.

Results:

In the cross-sectional analysis, men receiving chronic ADT had significantly lower total body BMD as compared with former ADT users and men with no ADT. In longitudinal analysis, a significant reduction in ultradistal forearm BMD was observed in both acute and chronic ADT users after 6 months (4.08% and 2.7%, P = .012 and .026, respectively). A significant reduction in total body BMD was observed in acute ADT users (2.99%, P = .032). Former ADT users had a significant increase in both lumbar spine and femoral neck BMD (2.84% and 1.59%, P = .008 and .002, respectively). The changes in BMD were not significantly different between acute and chronic ADT users. In the cross-sectional analysis, higher levels of PINP and CTX were observed in acute and chronic ADT users than former ADT users or PCa controls. In longitudinal analysis, the level of serum PINP and CTX did not change significantly from baseline to 6 months in acute, chronic, and former ADT users, or PCa controls, and the percentage change did not differ among the 4 groups.

Conclusions:

Men on acute ADT had a similar rate of bone loss to men on chronic ADT. Reversibility in ADT-induced bone loss was observed in those who discontinued ADT. Serum levels of PINP and CTX were higher in acute and chronic ADT users and levels returned to the range of PCa controls when treatment was withdrawn.

Vertebral and femoral bone mineral density and bone strength in prostate cancer patients assessed in phantomless PET/CT examinations

PURPOSE

Bone fracture risk assessed ancillary to positron emission tomography with computed tomography co-registration (PET/CT) could provide substantial clinical value to oncology patients with elevated fracture risk without introducing additional radiation dose. The purpose of our study was to investigate the feasibility of obtaining valid measurements of bone mineral density (BMD) and finite element analysis-derived bone strength of the hip and spine using PET/CT examinations of prostate cancer patients by comparing against values obtained using routine multidetector-row computed tomography (MDCT) scans-as validated in previous studies-as a reference standard.

MATERIALS AND METHODS

Men with prostate cancer (n=82, 71.6±8.3 years) underwent Fluorine-18 NaF PET/CT and routine MDCT within three months. Femoral neck and total hip areal BMD, vertebral trabecular BMD and femur and vertebral strength based on finite element analysis were assessed in 63 paired PET/CT and MDCT examinations using phantomless calibration and Biomechanical-CT analysis. Men with osteoporosis or fragile bone strength identified at either the hip or spine (vertebral trabecular BMD ≤80mg/cm³, femoral neck or total hip T-score ≤-2.5, vertebral strength ≤6500N and femoral strength ≤3500N, respectively) were considered to be at high risk of fracture. PET/CT- versus MDCT-based BMD and strength measurements were compared using paired t-tests, linear regression and by generating Bland-Altman plots. Agreement in fracture-risk classification was assessed in a contingency table.

RESULTS

All measurements from PET/CT versus MDCT were strongly correlated (R²=0.93-0.97; P<0.0001 for all). Mean differences for total hip areal BMD (0.001g/cm², 1.1%), femoral strength (-60N, 1.3%), vertebral trabecular BMD (2mg/cm³, 2.6%) and vertebral strength (150N; 1.7%) measurements were not statistically significant (P>0.05 for all), whereas the mean difference in femoral neck areal BMD measurements was small but significant (-0.018g/cm²; -2.5%; P=0.007). The agreement between PET/CT and MDCT for fracture-risk classification was 97% (0.89 kappa for repeatability).

CONCLUSION

Ancillary analyses of BMD, bone strength, and fracture risk agreed well between PET/CT and MDCT, suggesting that PET/CT can be used opportunistically to comprehensively assess bone integrity. In subjects with high fracture risk such as cancer patients this may serve as an additional clinical tool to guide therapy planning and prevention of fractures.

Bone health and its correlates in Korean prostate cancer patients receiving androgen deprivation therapy

PURPOSE

This study aimed to examine bone health status, identify factors associated with bone mineral density (BMD), and determine potential risk factors for osteoporosis in Korean prostate cancer patients receiving androgen deprivation therapy (ADT).

METHODS

Using a cross-sectional descriptive design, we recruited 139 men with prostate cancer receiving ADT at two university-based hospitals in South Korea. Participants completed a self-reported questionnaire and underwent dual energy X-ray absorptiometry testing. BMD (gm/cm(2)), bone health status (normal BMD, osteopenia, and osteoporosis), and lifestyle variables (physical activity, smoking, and alcohol consumption) were measured.

RESULTS

The prevalence in our sample was 49.6% for osteopenia and 17.3% for osteoporosis. In multivariate linear regression analyses, BMD was positively associated with body mass index, number of comorbidities, and level of physical activity and negatively associated with being unemployed or retired, having a lower monthly income, and being treated with gonadotropin-releasing hormone therapy alone. In logistic regression analyses, potential risk factors for osteoporosis were low monthly income (OR = 4.33, p = 0.011), receipt of radiation therapy (OR = 4.69, p = 0.018), and lack of regular physical activity (OR = 2.63, p = 0.035).

CONCLUSIONS

Our results suggest that a proportion of prostate cancer survivors who are receiving ADT warrant monitoring to prevent osteoporosis, particularly men of lower economic status and those having lower levels of physical activity. Nurses can play an important role in screening these high risk groups.

Zoledronic acid prevents decreases in bone mineral density in patients with prostate cancer undergoing combined androgen blockade

The aim of this study was to evaluate the effect of zoledronic acid (ZA) on bone mineral density (BMD) in patients with prostate cancer receiving combined androgen blockade (CAB) as a first-line androgen deprivation therapy. Patients receiving CAB for prostate cancer without bone metastasis were candidates for this study. Forty-two patients were randomly assigned to receive either ZA or no treatment. BMD were measured at baseline and at 12 months. Bone-turnover markers, including cross-linked N-telopeptide of type I collagen (NTX), C-telopeptide of type I collagen (ICTP), and bone-specific alkaline phosphatase (BAP), were assessed during study periods. Patients on ZA maintained BMD after a year of treatment. Change in T-score from baseline differed significantly between the two groups (P=0.009). An inverse correlation was demonstrated between baseline and change in T-score in the ZA group. While ZA prevented an increase in ICTP and BAP, the increase in NTX was suppressed only in patients with low baseline T-score. ZA prevented a decrease in BMD in patients undergoing CAB, especially those with lower baseline BMD.

Bone turnover markers in patients with prostate carcinoma: influence of sex steroids levels

There are limited data about bone turnover markers (BTM) in androgen deprivation therapy (ADT)-treated prostate cancer (PCa) patients, and the relationship between sex steroids, bone mass, and BTM has not been explored. Our objective was to analyze the influence of sex steroids levels on BTM in patients with PCa treated with or without ADT. We performed a cross-sectional study including 83 subjects with PCa (54% with ADT). BTM, bone mineral density (BMD), and sex steroids were determined. BTM were inversely related to serum level of estrogens. Tartrate-specific acid phosphatase (TRAP-5b) showed a negative correlation with free estradiol (Free E) (r = -0.274, p = 0.014) and Bio E (r = -0.256, p = 0.022) that remained after adjustment for age: Free E (β = -0.241, p = 0.03) and Bio E (β = -0.213, p = 0.063). Bone-specific alkaline phosphatase (BSAP) concentrations were inversely related to Free E (r = -0.281, p = 0.011, age-adjusted β = -0.256, p = 0.024). There was a negative correlation between osteocalcin (OC) levels and Free E (r = -0.195, p = 0.082; age-adjusted β = -0.203, p = 0.076) and Bio E (r = -0.215, p = 0.054; age-adjusted β = -0.240, p = 0.039). BTM and androgens were inversely related to TRAP-5b: total testosterone (total T) (r = -0.238, p = 0.033), Free T (r = -0.309, p = 0.05), and Bio T (r = -0.310, p = 0.05), but these correlations disappeared after age-adjustment. We did not find any relationship between BMD at different locations and sex steroids. In conclusion, in patients with PCa, estrogen levels influence bone resorption and bone formation whereas androgens may exert actions only in bone resorption. These results suggest that estradiol is the main sex steroid that regulates bone metabolism in males with prostate carcinoma.

Gender difference in bone metastasis of human small cell lung cancer, SBC-5 cells in natural killer-cell depleted severe combined immunodeficient mice

Lung cancer frequently develops multiple organ metastases, which thus makes this disease a leading cause of malignancy-related death worldwide. A gender difference is reported to affect the incidence and mortality of lung cancer; however, whether and how the gender difference is involved in lung cancer metastasis is unclear. This study evaluated the gender difference in multiple organ metastases in human small cell lung cancer (SBC-5) cells by using natural killer cell-depleted severe combined immunodeficient mice. Among multiple organ metastases, only bone metastasis formation significantly increased in female mice in comparison to males, while no significant difference was observed in the metastases to the liver and lungs. The suppression of androgen by castration or androgen receptor antagonist treatment in male mice also induced a significant increase of bone metastases. The number of osteoclasts in the bone metastatic lesions was greater in female mice and in mice with androgen suppression than in control male. However, there was no significant difference in the serum concentration of parathyroid hormone-related protein (PTHrP) associated with gender or androgen suppression. An in vitro study also indicated that sex steroid treatment had no effect on the proliferation or PTHrP production in SBC-5 cells. These results indicate that the balance of sex steroids therefore plays an important role in the formation of bone metastasis in small cell lung cancer, and suggests diverse mechanisms of interaction between cancer cells and host cells in the bone microenvironment.

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.

Maximal androgen blockade for advanced prostate cancer

Maximal androgen blockade (MAB) refers to the combination of medical (gonadotrophin-releasing hormone agonist) or surgical castration with an anti-androgen for the treatment of advanced prostate cancer. A substantial body of basic research has improved our understanding of the interactions between the anti-androgens, the androgen receptor, and androgen response elements in the genome. Anti-androgens act by two primary mechanisms: inhibition of ligand (androgen) binding to the androgen receptor, and inhibition of androgen-independent activation of the receptor. The latter mechanism occurs via several pathways, including inhibiting nuclear co-activators, activating co-suppressors, and inhibiting transcription of a variety of androgen-regulated genes. It is more accurate to refer to these compounds as androgen-receptor antagonists, since they inhibit activation whether this is androgen-mediated or not. Within the class of non-steroidal anti-androgens, there is variation in the degree to which ligand-independent activation is inhibited. Over the last 25 years, approximately 30 clinical trials have addressed the benefit of MAB versus monotherapy. Most of these trials have evaluated flutamide or nilutamide. Several meta-analyses suggest a modest survival benefit of these drugs, amounting to an 8% mortality reduction at 5 years. Preclinical data and two randomized trials -- one historic and one current -- suggest that bicalutamide may be a more effective drug in this respect. This requires confirmation pending further maturity of the current trial, which is the only one directly comparing bicalutamide plus castration to castration alone. In prostate cancer patients at high risk for mortality (based on extent of disease or prostate-specific antigen kinetics), combination therapy with bicalutamide should be considered in preference to monotherapy.