The role of gonadotrophin-releasing hormone antagonists in the treatment of patients with advanced hormone-dependent prostate cancer in the UK

Cardiovascular adverse events-related to GnRH agonists and GnRH antagonists: analysis of real-life data from Eudra-Vigilance and Food and Drug Administration databases entries

INTRODUCTION AND OBJECTIVES

GnRH agonists and GnRH antagonists are two of the mainstays of hormonal therapy (HT) for prostate cancer (PCa). These drugs are at increased risk of cardiovascular (CV) adverse events (AEs). Aim of our study was to compare real-life data on AEs associated with GnRH agonists and GnRH antagonists based on Eudra-Vigilance (EV) and Food and Drug Administration (FDA) reported AEs.

MATERIALS AND METHODS

EV and FDA databases were queried and the number of CV adverse events (AEs) for degarelix, buserelin, goserelin, leuprorelin, triptorelin until September 2021 were recorded. Specific CV AEs were recorded and data were analyzed per age and severity. pooled relative risk (PRR) was used to compare data between drugs.

RESULTS

CV events were reported in 315/5128 (6%) for Degarelix, in 55/628 for Buserelin (9%), in 843/12,145 (7%) for Goserelin, in 3395/71,160 (5%) for Leuprorelin and in 214/4969 (5%) for Triptorelin. In terms of specific CV disorders, Degarelix presented lower risk of hypertension (PRR 0.60 (95% CI 0.37-0.98), p = 0.04), of myocardial infarction (PRR 0.05 (95% CI 0.01-0.39), p < 0.01) and thrombosis (PRR 0.14 (0.02-1.07), p = 0.06) when compared to GnRH agonists. Overall, younger patients (<65 years) presented a very low risk of CV AEs. Side effects were classified as serious in 90-96% of the cases. Fatal AEs were 5-20% over the CV AEs and 0.2-1% over the total AEs.

CONCLUSIONS

Real-life data are consistent with registry studies regarding side effects related to HT. Real-life data suggest GnRH agonists are associated with higher CV AEs when compared to GnRH antagonists. Clinicians should consider these data when prescribing HT especially in patients with CV comorbidities.

Cardiovascular risk of gonadotropin-releasing hormone antagonist versus agonist in men with prostate cancer: an observational study in Taiwan

BACKGROUND

The impact of gonadotropin-releasing hormone (GnRH) antagonist and agonist (GnRHa) treatment on cardiovascular disease (CVD) risk in prostate cancer (PCa) remains inconclusive due to conflicting findings. We compared the effects of GnRH antagonist and GnRHa treatments on CVD risk in patients with PCa and pre-existing CVD, in a Taiwan population-based database.

METHODS

We assessed the risk of major adverse CV events (MACE: ischemic heart disease [IHD], stroke, congestive heart failure [CHF] or all cause deaths) and composite CV events (IHD, stroke, CHF or CV deaths) occurring ≥90 days after androgen deprivation therapy (ADT) initiation in patients with PCa after 90 days of treatment with either GnRH antagonist (degarelix; n = 499) or GnRHa (goserelin, leuprolide, triptorelin; n = 15,127). Patients identified with pre-existing CVD had received cardiac therapy for IHD, reported a stroke or CHF within a year before ADT initiation. Adjusted hazard ratios (aHR) and 95% confidence interval (CI) were obtained for MACE and composite CV events risk after adjusting for age, baseline status of diabetes, hypertension and treatments received.

RESULTS

All GnRH antagonist-treated patients showed lower risk of composite CV events than the GnRHa-treated patients. The lower composite CV events risk associated with GnRH antagonist was also observed in patients with metastasis at diagnosis (aHR 0.16; 95% CI, 0.04-0.38; p = 0.013) and those receiving ADT for more than six months (aHR 0.30; 95% CI, 0.16-0.54; p < 0.0001). In patients with pre-existing CVD, the MACE risk was 33% lower (aHR 0.67; 95% CI, 0.46-0.96; p = 0.0299) and composite CV events risk was 84% lower (aHR 0.16; 95% CI, 0.05-0.50; p = 0.0017) in GnRH antagonist-treated than the GnRHa-treated patients.

CONCLUSIONS

In patients with PCa and pre-existing CVD, GnRH antagonist use was associated with lower risks for composite CV events and MACE compared with GnRHa.

A systematic review evaluating the effectiveness of exercise training on physical condition in prostate cancer patients undergoing androgen deprivation therapy

Background

Androgen deprivation therapy (ADT) is an effective prostate cancer (PCa) treatment strategy that can curb the development or progression of the disease. This review aimed to examine and summarize available systematic reviews/meta-analyses (SRs/MAs) of exercise training on physical condition of PCa patients undergoing ADT.

Methods

A comprehensive search of 8 databases was conducted for relevant literature published before April 25, 2022 with the language restrictions of Chinese and English. Two reviewers independently assessed the methodological quality, risk of bias, reporting quality, and evidence quality of the included SRs/MAs using a range of evaluation tools, including A Measurement Tool to Assess Systematic Reviews (AMSTAR) 2, Risk of Bias in Systematic Reviews (ROBIS), the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA), and Grades of Recommendations, Assessment, Development and Evaluation (GRADE).

Results

This review included 8 SRs/MAs which included a total of 94 studies. Ultimately, A total of 51 outcomes was included, regarding 11 different outcome categories. The AMSTAR-2 tool showed that 3 SRs/MAs had moderate methodological quality, 4 SRs/MAs had very low quality, and the remaining 1 had low quality. According to the ROBIS scale, 3 SRs/MAs had a high risk of bias. The PRISMA checklist showed that the primary reporting faults were protocol registration and funding source. The GRADE system was used to analyze the evidence quality of the 51 outcomes, and no high-quality evidence was found. However, moderate-quality evidence indicated that exercise training may improve body composition [by lowering body fat mass (BFM) and body fat rate (BFR)], muscular strength, and quality of life (QoL) in PCa patients undergoing ADT. Low-quality evidence demonstrated that exercise training could improve such symptoms as fatigue, depression, sexual function, and cardiometabolic changes.

Conclusions

Available evidence suggests that exercise training may be used as an adjuvant treatment for PCa patients undergoing ADT to improve several aspects of general health. Studies with more rigorous designs and larger sample sizes are needed to support our findings with more robust evidence.

Approaches to Prevent and Manage Cardiovascular Disease in Patients Receiving Therapy for Prostate Cancer

PURPOSE OF REVIEW

Prostate cancer (PCa) is amongst the most common cancers in men worldwide. Cardiovascular (CV) risk factors and CV disease (CVD) are common comorbidities in this patient population, posing a challenge for PCa-directed therapies which can cause or worsen CVRFs and CVDs. Herein, we summarize the approaches to prevent and manage CVD in patients with PCa receiving therapy.

RECENT FINDINGS

While patients with locally advanced and metastatic PCa benefit from hormonal therapy, these treatments can potentially cause CV toxicity. Androgen receptor targeting therapies, such as androgen deprivation therapy (ADT), can induce metabolic changes and directly impact cardiovascular function, thereby reducing cardiorespiratory fitness and increasing CV mortality. Moreover, more than half of the PCa patients have poorly controlled CV risk factors at baseline. Hence, there is an urgent need to address gaps in preventing and managing CVD in PCa patients. Screening and optimizing CV risk factors and CVD in patients undergoing ADT are essential to reduce CV mortality, the leading non-cancer cause of death in PCa survivors. The risk of CV morbidity and mortality can be further mitigated by considering the patient's cardiovascular risk profile when deciding the choice and duration of ADT. A multidisciplinary team-based approach is crucial to achieve the best outcomes for PCa patients undergoing therapy.

Cabazitaxel-Loaded Nanoparticles Reduce the Invasiveness in Metastatic Prostate Cancer Cells: Beyond the Classical Taxane Function

Bone-metastatic prostate cancer symbolizes the beginning of the later stages of the disease. We designed a cabazitaxel-loaded, poly (lactic-co-glycolic acid) (PLGA) nanoparticle using an emulsion-diffusion-evaporation technique. Bis (sulfosuccinimidyl) suberate (BS3) was non-covalently inserted into the nanoparticle as a linker for the conjugation of a bone-targeting moiety to the outside of the nanoparticle. We hypothesized that the nanoparticles would have the ability to inhibit the epithelial-to-mesenchymal transition (EMT), invasion, and migration in prostate cancer cells. Targeted, cabazitaxel-loaded nanoparticles attenuated the EMT marker, Vimentin, and led to an increased E-cadherin expression. These changes impart epithelial characteristics and inhibit invasive properties in cancer progression. Consequently, progression to distant sites is also mitigated. We observed the reduction of phosphorylated Src at tyrosine 416, along with increased expression of phosphorylated cofilin at serine 3. These changes could affect migration and invasion pathways in cancer cells. Both increased p-120 catenin and inhibition in IL-8 expression were seen in targeted, cabazitaxel-loaded nanoparticles. Overall, our data show that the targeted, cabazitaxel-loaded nanoparticles can act as a promising treatment for metastatic prostate cancer by inhibiting EMT, invasion, and migration, in prostate cancer cells.

Operative challenges of intramedullary nailing for subtrochanteric blastic pathological femur fracture: a case report

Prostate adenocarcinoma metastasizes to bone and forms fragile blastic lesions, which can present as dense obstacles intraoperatively. There are limited reports on the challenges surgeons face when operating through these lesions. A 60-year-old male with a pathologic subtrochanteric femur fracture in the presence of blastic lesions was successfully treated with intramedullary (IM) fixation. Pathologic fractures from blastic bone lesions are expected to increase in prevalence as survivability improves for metastatic prostate cancer. Orthopedic surgeons, when performing IM fixation for these fractures, should be prepared to utilize accessory equipment and should adopt creative techniques for reduction and fixation.

Relugolix in the management of prostate cancer

INTRODUCTION

Relugolix is the first oral gonadotrophin-releasing hormone (GnRH) receptor antagonist. Based on the phase III HERO trial results, relugolix received Food and Drug Administration approval for adult patients with advanced prostate cancer (PCa).

AREAS COVERED

: We provide an overview of the preclinical and clinical development of relugolix and its role in the current treatment landscape of PCa.

EXPERT OPINION

Relugolix leads to rapid inhibition of testicular production of testosterone and its rapid recovery upon discontinuation. In the HERO trial, relugolix was associated with a superior cardiovascular safety profile compared to GnRH agonists. These attributes make relugolix a promising therapy for patients with pre-existing cardiovascular co-morbidities, those pursuing intermittent androgen deprivation therapy, and those who desire rapid testosterone recovery during "off-treatment" periods. In the HERO trial, very few patients received concomitant enzalutamide (n=17, 2.7%) or docetaxel (n<10, 1.3%). Safety of relugolix has not been established in combination with many androgen-receptor-axis targeted therapies (e.g. abiraterone, apalutamide), cabazitaxel, or lutetium Lu 177 vipivotide tetraxetan, which precludes its use in combination with these agents. In addition, being an oral drug, relugolix may also be associated with challenges of affordability, adherence, and compliance in this predominantly elderly population.

Hydroxyl Group-Targeted Conjugate and Its Self-Assembled Nanoparticle of Peptide Drug: Effect of Degree of Saturation of Fatty Acids and Modification of Physicochemical Properties

Purpose

To conjugate different degree of saturation of C18 fatty acids (stearic acid, oleic acid, and linoleic acid) with the hydroxyl groups of leuprolide acetate (LEU acetate) and to investigate the controlled release and enhanced permeability through self-assembled nanoparticles (L18FNs).

Methods

Yamaguchi esterification with benzoyl chloride and DMAP (4-Dimethylaminopyridine) allowed the conjugation of the fatty acid to the hydroxyl group of LEU. The three conjugates were then designated as stearic acid-conjugated LEU, LSC, oleic acid-conjugated LEU, LOC, and linoleic acid-conjugated LEU, LLC, respectively. The conjugates (L18FCs) were purified using preparative HPLC (Prep-HPLC) and identified through various instrumental analyses.

Results

The zeta potential, particle size, and morphology of each L18FNs were evaluated. In the case of LSNs, the zeta potential value was relatively low and the particle size was larger than LONs and LLNs owing to the higher hydrophobicity of saturated fatty chain, while the LLNs showed a higher zeta potential and smaller particle size. In human plasma, LLC showed the fastest degradation rate with the highest accumulative drug release. The permeability of L18FNs was analyzed through the Franz diffusion cell experiment, confirming that the degree of saturation of fatty acids affects the permeability of LFNs. While the permeability of LSNs was not significantly enhanced due to higher particle size after nanonization, LONs and LLNs increased 1.56 and 1.85 times in permeation, respectively, compared to LEU.

Conclusion

Utilization of different degree of saturation of fatty acids to conjugate a peptide drug could provide pharmaceutical versatility via self-assembly and modification of physicochemical properties.

Androgen deprivation therapy and cardiovascular risk in prostate cancer

INTRODUCTION

Androgen-deprivation therapy (ADT), with or without palliative local treatments, is the standard of care for many patients with locally-advanced and/or metastatic prostate cancer. However, the possible cardiovascular (CV) risks associated with gonadotropin-releasing hormone (GnRH) antagonists and agonists continue to be the subject of concern, especially in a patient population that may already be at increased CV risk.

EVIDENCE ACQUISITION

The present review provides a narrative summary of the evidence regarding the CV risks associated with GnRH antagonists and agonists from randomized clinical trials (RCTs), real-world evidence, and meta-analyses.

EVIDENCE SYNTHESIS

From RCTs, it appears clear that there is a direct class effect for CV risk in patients with prostate cancer being administered GnRH agonists and antagonists, with the latter being associated with reduced CV risk. Real-world data and the available meta-analyses largely indicate that CV risk is lower with GnRH antagonists than with GnRH agonists.

CONCLUSIONS

A review of the pathophysiological mechanisms of gives further support to the possibility that GnRH antagonists are associated with lower CV risk than agonists. It can be highlighted that when treating patients with advanced or metastatic prostate cancer it is important to screen for underlying comorbidities prior to choosing the most appropriate therapy; moreover, patients should be closely monitored for factors associated with CV risk in order to optimize outcomes. Further studies are needed to define the most appropriate treatment according to the individual patient characteristics.

Impacts of endocrine-disrupting chemicals on prostate function and cancer

Because of their historical mode of action, endocrine-disrupting chemicals (EDCs) are associated with sex-steroid receptors, namely the two estrogen receptors (ERα and ERβ) and the androgen receptor (AR). Broadly, EDCs can modulate sex-steroid receptor functions. They can also indirectly impact the androgen and estrogen pathways by influencing steroidogenesis, expression of AR or ERs, and their respective activity as transcription factors. Additionally, many of these chemicals have multiple cellular targets other than sex-steroid receptors, which results in a myriad of potential effects in humans. The current article reviews the association between prostate cancer and the endocrine-disrupting functions of four prominent EDC families: bisphenols, phthalates, phytoestrogens, and mycoestrogens. Results from both in vitro and in vivo models are included and discussed to better assess the molecular mechanisms by which EDCs can modify prostate biology. To overcome the heterogeneity of results published, we established common guidelines to properly study EDCs in the context of endocrine diseases. Firstly, the expression of sex-steroid receptors in the models used must be determined before testing. Then, in parallel to EDCs, pharmacological compounds acting as positive (agonists) and negative controls (antagonists) have to be employed. Finally, EDCs need to be used in a precise range of concentrations to modulate sex-steroid receptors and avoid off-target effects. By adequately integrating molecular endocrinology aspects in EDC studies and identifying their underlying molecular mechanisms, we will truly understand their impact on prostate cancer and distinguish those that favor the progression of the disease from those that slow down tumor development.

Assessment and Mitigation of Cardiovascular Risk for Prostate Cancer Patients: A Review of the Evidence

BACKGROUND

Cardiovascular disease (CVD) is a common comorbidity in patients with prostate cancer. In this review, we summarize the published literature on the association of cardiovascular risk with androgen deprivation therapy (ADT) treatment and explore the potential differences between the gonadotropin-releasing hormone (GnRH) agonists and antagonists and the molecular mechanisms that may be involved. We also provide a practical outlook on the identification of underlying CV risk and explore the different stratification tools available.

RESULTS

While not definitive, the current evidence suggests that GnRH antagonists may be associated with lower rates of certain CV events vs agonists, particularly in patients with preexisting CVD. Risk reduction strategies such as lifestyle advice, consideration of ADT modality, and comedications may help to reduce CV risk factors and improve outcomes in prostate cancer patients receiving ADT.

CONCLUSIONS

Given all the data that is currently available, identification of baseline CV risk factors may be key to risk mitigation in patients with prostate cancer receiving ADT.

Exploring the association between use of gonadotropin releasing hormones agonists and prostate cancer diagnosis per se and diabetes control in men with type 2 diabetes mellitus: a nationwide, population-based cohort study

BACKGROUND

Gonadotropin Releasing Hormones agonists (GnRH), which are first line treatment for metastatic prostate cancer (PCa), increase risk of type 2 diabetes mellitus (T2DM). This study aims to quantify the association of use of GnRH with diabetes control in PCa men with T2DM.

METHODS

Nationwide population-based cohort study in the Swedish National Diabetes Register and Prostate Cancer data Base Sweden 4.1, on the association between GnRH and diabetes control in T2DM men with PCa by comparing T2DM men with PCa vs. without PCa, as well as comparing T2DM men with PCa on or not on GnRH. The primary exposure was use of GnRH. Worsening diabetes control was the primary outcome, defined as: 1) HbA1c rose to 58 mmol/mol or higher; 2) HbA1c increase by 10 mmol/mol or more; 3) Start of antidiabetic drugs or switch to insulin. We also combined all above definitions. Cox proportional hazards regression was used to analyze the association.

RESULTS

There were 5714 T2DM men with PCa of whom 692 were on GnRH and 28,445 PCa-free men with T2DM with similar baseline characteristics. Diabetes control was worse in men with GnRH vs. PCa-free men (HR: 1.24, 95% CI: 1.13-1.34) as well as compared with PCa men without GnRH (HR:1.58, 95% CI: 1.39-1.80), when we defined the worsening control of diabetes by combining all definitions above.

CONCLUSION

Use of GnRH in T2DM men with PCa was associated with worse glycemic control. The findings highlight the need to closely monitor diabetes control in men with T2DM and PCa starting GnRH.

The Relationship Between Bone and Reproductive Hormones Beyond Estrogens and Androgens

Reproductive hormones play a crucial role in the growth and maintenance of the mammalian skeleton. Indeed, the biological significance for this hormonal regulation of skeletal homeostasis is best illustrated by common clinical reproductive disorders, such as primary ovarian insufficiency, hypothalamic amenorrhea, congenital hypogonadotropic hypogonadism, and early menopause, which contribute to the clinical burden of low bone mineral density and increased risk for fragility fracture. Emerging evidence relating to traditional reproductive hormones and the recent discovery of newer reproductive neuropeptides and hormones has deepened our understanding of the interaction between bone and the reproductive system. In this review, we provide a contemporary summary of the literature examining the relationship between bone biology and reproductive signals that extend beyond estrogens and androgens, and include kisspeptin, gonadotropin-releasing hormone, follicle-stimulating hormone, luteinizing hormone, prolactin, progesterone, inhibin, activin, and relaxin. A comprehensive and up-to-date review of the recent basic and clinical research advances is essential given the prevalence of clinical reproductive disorders, the emerging roles of upstream reproductive hormones in bone physiology, as well as the urgent need to develop novel safe and effective therapies for bone fragility in a rapidly aging population.

Relugolix, an oral gonadotropin-releasing hormone antagonist for the treatment of prostate cancer

Androgen deprivation therapy using gonadotropin-releasing hormone (GnRH) analogues is standard treatment for intermediate and advanced prostate cancer. GnRH agonist therapy results in an initial testosterone flare, and increased metabolic and cardiovascular risks. The GnRH antagonist relugolix is able to reduce serum testosterone levels in men with prostate cancer without inducing testosterone flare. In the HERO Phase III trial, relugolix was superior to leuprolide acetate at rapidly reducing testosterone and continuously suppressing testosterone, with faster post-treatment recovery of testosterone levels. Relugolix was associated with a 54% lower incidence of major adverse cardiovascular events than leuprolide acetate. As the first oral GnRH antagonist approved for the treatment of advanced prostate cancer, relugolix offers a new treatment option.

miRNAs and androgen deprivation therapy for prostate cancer

Androgen deprivation therapy (ADT) is mainly used for the treatment of advanced, metastatic or recurrent prostate cancer (PCa). However, patients progress to ADT resistance and castration-resistant prostate cancer (CRPC) with a poor prognosis. Reliable validated markers of ADT resistance with proven clinical utility are necessary for timely correction of the therapy as well as for improvement of patient quality of life. MiRNAs involved in the ADT response and CRPC development via multiple mechanisms may act as biomarkers for patient outcomes. Available data on miRNAs associated with the ADT response (resistance and sensitivity) are summarized and analyzed in the manuscript, including analyses using bioinformatics resources. Molecular targets of miRNAs, as well as reciprocal relations between miRNAs and their targets, were studied using different databases. Special attention was dedicated to the mechanisms of ADT resistance and CRPC development, including testosterone, PI3K-AKT, VEGF pathways and associated genes. Several different approaches can be used to search for miRNAs associated with the ADT response, each of which focuses on the associated set of miRNAs - potential markers of ADT. The intersection of these approaches and combined analysis allowed us to select the most promising miRNA markers of the ADT response. Meta-analysis of the current data indicated that the selected 5 miRNAs (miRNAs - 125b, miR-21, miR-23b, miR-27b and miR-221) and 14 genes are involved in the regulation of key processes of CRPC development and represent the most promising predictors of the ADT response, further demonstrating their potential in combination therapy for advanced PCa.

Relugolix: a novel androgen deprivation therapy for management of patients with advanced prostate cancer

Androgen deprivation therapy (ADT) is the foundation of treatment for patients with locally advanced, recurrent and metastatic prostate cancer, most commonly using luteinizing releasing hormone (LHRH) agonists. More recently, a new approach to ADT has emerged with the development of gonadotropin-releasing hormone (GnRH) antagonists, which aim to overcome some of the potential adverse physiologic effects of LHRH agonists. This article focuses on the newest GnRH antagonist, relugolix - a once-daily treatment and the only oral GnRH antagonist that has now been approved for the treatment of advanced prostate cancer. In phase II and III studies, relugolix achieved rapid and sustained castration without the testosterone surge associated with LHRH agonists, thus avoiding the potential clinical consequences of tumor flare and the necessity for concomitant anti-androgen therapy. Relugolix also achieved rapid testosterone recovery, which may potentially reduce ADT-related adverse events and offer opportunities for combination and intermittent therapy strategies. Cardiovascular safety is a particular concern in men with prostate cancer and ADT further increases cardiovascular risk: indeed, LHRH agonists are required to have a drug label warning about an increased risk of cardiovascular disease. Data from the phase III HERO study demonstrate an improved cardiac safety profile for the GnRH antagonist relugolix compared with the LHRH agonist leuprolide, including a significantly reduced risk for a major adverse cardiovascular event. Taken together, the data indicate that relugolix may mitigate some of the cardiovascular concerns surrounding ADT and has the potential to become a new standard of care for men with prostate cancer. In summary, relugolix represents a novel and recently available prostate cancer management strategy, incorporating the mechanistic advantages of GnRH antagonists and the potential benefits of oral administration.

Androgen deprivation therapy and side effects: are GnRH antagonists safer?

Androgen deprivation therapy (ADT) with gonadotropin-releasing hormone (GnRH) agonists and antagonists is the mainstay of advanced prostate cancer treatment. Both drug classes decrease levels of luteinizing hormone and follicle-stimulating hormones (FSH), thereby lowering testosterone to castrate levels. This is associated with adverse events (AEs), including cardiovascular (CV) disorders, bone fractures, metabolic dysfunction, and impaired cognitive function. This literature review discusses these AEs, with a focus on CV and bone-related events. A hypothesis-generating meta-analysis of six clinical trials showed a potentially increased risk for CV disorders with GnRH agonists versus the GnRH antagonist degarelix. While no study has directly compared GnRH agonists versus antagonists with a primary CV outcome, one hypothesis for this observation is that GnRH agonists lead to initial surges in FSH that may negatively impact CV health, whereas antagonists do not. GnRH agonists are associated with metabolic and cognitive AEs and while data are lacking for GnRH antagonists, no differences in risk are predicted. Other common AEs with ADT include injection site reactions, which are much more common with degarelix than with GnRH agonists, which may reflect differing administration and injection techniques. Future studies are needed to further evaluate and compare the safety profiles of GnRH agonists and antagonists, especially in patients with pre-existing CV disease and other co-morbidities. Physicians should carefully evaluate benefits and risks when prescribing ADT and ensure that side effects are well managed.

Does Exist a Differential Impact of Degarelix Versus LHRH Agonists on Cardiovascular Safety? Evidences From Randomized and Real-World Studies

The main systemic therapy for the management of hormone-sensitive prostate cancer (PC) is androgen deprivation therapy (ADT), with the use of long-acting luteinizing hormone releasing-hormone (LHRH) agonists considered the main form of ADT used in clinical practice to obtain castration in PC. The concomitant administration of antiandrogens for the first weeks could reduce the incidence of clinical effects related to the testosterone flare-up in the first injection of LHRH. On the contrary, Gonadotropin Rh (GnRH) antagonists produce a rapid decrease of testosterone levels without the initial flare-up, with degarelix commonly used in clinical practice to induce castration in PC patients. Even if no long-term data are reported in terms of survival to define a superiority of GnRH or LHRH, for oncological efficacy and PC control, data from randomized clinical trials and from real-life experiences, suggest a difference in cardiovascular risk of patients starting ADT. The age-related decline in testosterone levels may represent a factor connected to the increase of cardiovascular disease risk, however, the role of ADT in increasing CV events remains controversial. For these reasons, the aim of the paper is to synthesize the difference in cardiovascular risk between LHRH and degarelix in patients undergoing ADT. A difference in cardiovascular risk could be indeed an important parameter in the evaluation of these two forms of castration therapy. The Randomized trials analyzed in this paper sustain a possible protective role for degarelix versus LHRH agonists in reducing the rate of new CV events and interventions in the short-term period. On the contrary, real-word data are contradictory in different national experiences and are strongly conditioned by huge differences between the LHRH agonists group and the degarelix group.

Comparing the risk of cardiovascular disease following GnRH agonist and GnRH antagonist therapy for patient with prostate cancer: a systematic review and meta-analysis

INTRODUCTION

The aim of this review is to compare the risk of cardiovascular disease (CVD) following gonadotropin-releasing hormone (GnRH) agonist and GnRH antagonist therapy for patient with prostate cancer (PCa).

EVIDENCE ACQUISITION

We searched PubMed, Web of science, Opengery, Cochrane library databases and international congress reports for studies published before December 2019. This meta-analysis was conducted using Stata v. 12.0. Relative ratios (RRs) and their credible intervals (CI) were applied for the cardiovascular safety evaluation of androgen-deprivation therapy (ADT) medical interventions, including GnRH agonist and GnRH antagonist therapy. In addition, fixed-effect or random-effect models were applied in the statistical analyses according to the heterogeneity.

EVIDENCE SYNTHESIS

Six articles including 32,997 participants were analyzed with a random effects model. The results of meta-analysis showed that compared with GnRH agonist, the incidents of CVD was equal to GnRH antagonist therapy for patient with PCa (RR=0.98, 95% CI: 0.94-1.02). When considering, under sub-group analysis with randomized controlled trials (RCTs) or controlled clinical trials (CCTs), no statistical differences in risk of CVD were found in two sub-group analyses. No evidence of publication bias was found in our meta-analysis by a funnel plot (Pr> | z |=0.26).

CONCLUSIONS

This meta-analysis indicates that compared treatment with GnRH antagonist, risks of CVD in PCa patients was the same as GnRH agonist. Further RCTs are strongly required to provide more definitive evidence.

Cardiovascular risk profiles of GnRH agonists and antagonists: real-world analysis from UK general practice

PURPOSE

Androgen deprivation therapy (ADT) is the mainstay for the management of metastatic prostate cancer. Available pharmaceutical ADTs include gonadotropin-releasing hormone (GnRH) agonists and antagonists. Here, real-world data are presented from the UK general practitioner Optimum Patient Care Research Database. The study investigated the hypothesis that GnRH antagonists have lower cardiac event rates than GnRH agonists.

METHODS

The incidence of cardiac events following initiation of GnRH antagonist or agonist therapy was investigated in a population-based cohort study conducted in UK primary care between 2010 and 2017.

RESULTS

Analysis of real-world data from the UK primary care setting showed that relative risk of experiencing cardiac events was significantly lower with degarelix, a GnRH antagonist, compared with GnRH agonists (risk ratio: 0.39 [95% confidence interval 0.191, 0.799]; p = 0.01). Patients that received degarelix as first-line treatment switched treatment more frequently (33.7%), often to a GnRH agonist, than those who initiated treatment with a GnRH agonist (6.7-18.6%).

CONCLUSION

Screening for known or underlying vascular disease and identifying those at high risk of a cardiac event is important for risk mitigation in patients with prostate cancer receiving hormone therapy. The GnRH antagonist degarelix conferred a significantly lower risk of cardiac events than GnRH agonists. Prior to treatment, patients should be stratified based on level of cardiovascular (CV) risk, and appropriate lifestyle, and pharmacological interventions to mitigate CV risk should be recommended. CV risk factors and patient response to the intervention should be monitored at regular intervals.

Optimizing screening and management of cardiovascular health in prostate cancer: A review

In clinical practice, cancer management does not consistently encompass screening and identification of cardiovascular (CV) risk. The use of androgen deprivation therapy (ADT) in prostate cancer has been associated with increased CV risk and development of metabolic syndrome, necessitating identification of patients at risk in this population (e.g., those with pre-existing CV disease). A multidisciplinary team of Canadian physicians was assembled to develop a series of recommendations intended to identify patients who may benefit from optimal management of their CV disease and/or modification of cardiac risk factors. A key goal was the development of a simple screening tool for identification of patients with pre-existing CV disease. This simple and inclusive set of recommendations are intended for use within urology clinics to facilitate holistic approaches and simplify the management of patients.

Cancer stem cell and mesenchymal cell cooperative actions in metastasis progression and hormone resistance in prostate cancer: Potential role of androgen and gonadotropin‑releasing hormone receptors (Review)

Prostate cancer (PCa) is the leading cause of male cancer‑associated mortality worldwide. Mortality is associated with metastasis and hormone resistance. Cellular, genetic and molecular mechanisms underlying metastatic progression and hormone resistance are poorly understood. Studies have investigated the local effects of gonadotropin‑releasing hormone (GnRH) analogs (used for androgen deprivation treatments) and the presence of the GnRH receptor (GnRH‑R) on PCa cells. Furthermore, cell subpopulations with stem‑like properties, or cancer stem cells, have been isolated and characterized using a cell culture system derived from explants of human prostate tumors. In addition, the development of preclinical orthotopic models of human PCa in a nonobese diabetic/severe combined immunodeficiency mouse model of compromised immunity has enabled the establishment of a reproducible system of metastatic progression in vivo. There is increasing evidence that metastasis is a complex process involving the cooperative actions of different cancer cell subpopulations, in which cancer stem‑like cells would be responsible for the final step of colonizing premetastatic niches. It has been hypothesized that PCa cells with stemness and mesenchymal signatures act cooperatively in metastatic progression and the inhibition of stemness genes, and that overexpression of androgen receptor (AR) and GnRH‑R decreases the rate the metastasis and sensitizes tumors to hormone therapy. The aim of the present review is to analyze the evidence regarding this cooperative process and the possible influence of stem‑like cell phenotypes, AR and GnRH‑R in metastatic progression and hormone resistance. These aspects may represent an important contribution in the understanding of the mechanisms underlying metastasis and hormone resistance in PCa, and potential routes to blocking these processes, enabling the development of novel therapies that would be particularly relevant for patients with metastatic and castration‑resistant PCa.

Real-world insights into risk of developing cardiovascular disease following GnRH agonists versus antagonists for prostate cancer: a methodological protocol to a study using five European databases

One of the more recently investigated adverse long-term side effects of gonadotropin-releasing hormone (GnRH) agonists for prostate cancer (PCa) is cardiovascular disease (CVD). Studies suggest lower risk of CVD following GnRH antagonists (degarelix) than GnRH agonists. This protocol describes precise codes used to extract variables from five European databases for a study that compares risk of CVD following GnRH agonists and antagonists for PCa. PCa men on primary GnRH agonists or antagonists were identified from the UK THIN (The Health Improvement Network) database, National Health Service (NHS) Scotland, Belgian Cancer Registry (BCR), Dutch PHARMO Database Network and French National Database (SNIIRAM). Cohort entry was defined as date of treatment initiation. CVD event was defined as any first incident or fatal CVD after cohort entry. Readcodes in THIN and ICD codes in NHS Scotland, BCR, PHARMO and SNIIRAM were used to extract variables. Risk of Bias in Non-randomised studies of Interventions (ROBINS-I) tool was used to assess the potential risk of biases in this study. 51 572 men with a median follow-up time of 2 years started on GnRH agonists and 2 417 men with a median follow-up time of 1 year started on GnRH antagonists between 2010 and 2017 in the UK, Scotland, Belgium, the Netherlands and France. Data from five countries improved the study power and internal validity required to compare risk of CVD between GnRH agonists and antagonists, the latter being a fairly new drug with limited data in individual countries.

Regulation of prostate cancer by hormone-responsive G protein-coupled receptors

Regulation of prostate cancer by androgen and androgen receptor (AR), and blockade of AR signaling by AR antagonists and steroidogenic enzyme inhibitors have been extensively studied. G protein-coupled receptors (GPCRs) are a family of membrane receptors that regulate almost all physiological processes. Nearly 40% of FDA-approved drugs in the market target GPCRs. A variety of GPCRs that mediate reproductive function have been demonstrated to be involved in the regulation of prostate cancer. These GPCRs include gonadotropin-releasing hormone receptor, luteinizing hormone receptor, follicle-stimulating hormone receptor, relaxin receptor, ghrelin receptor, and kisspeptin receptor. We highlight here GPCR regulation of prostate cancer by these GPCRs. Further therapeutic approaches targeting these GPCRs for the treatment of prostate cancer are summarized.

Additive effect of simultaneous continuous administration of degarelix and TAK-448 on LH suppression in a castrated rat model

Gonadotropin releasing hormone (GnRH) analogs have long been used in androgen deprivation therapy (ADT) in the treatment of prostate cancer. Chronic administration of either GnRH agonists or antagonists leads to suppression of testosterone production in the testes via either downregulation or direct blockade of the GnRH receptor in the pituitary, respectively. Chronic administration of kisspeptin analogs has more recently been shown to lead to testosterone suppression via desensitization of GnRH neurons in the hypothalamus and an optimized kisspeptin analog, TAK-448, was proven effective in a small phase 1 trial. The current study explored the hypothesis that co-administration of TAK-448 and the GnRH antagonist, degarelix, would have an additive effect on hormonal suppression, as a result of simultaneous intervention in separate steps in the same pathway. TAK-448 or degarelix were first administered individually to castrated rats in order to identify low doses capable of partial or no suppression of luteinizing hormone (LH). In the second step, combinations of the low doses of TAK-448 and degarelix were assessed in a 14 day study and compared to the drugs administered separately. The results showed that simultaneous intervention at the kisspeptin and GnRH receptors caused a more pronounced LH suppression than either drug alone, demonstrating an additive or potentiating effect. These results suggest that such a drug combination may hold promise as novel forms of androgen deprivation therapy in the treatment of prostate cancer.

Reporting and ideal testosterone levels in men undergoing androgen deprivation for prostate cancer-time for a rethink?

BACKGROUND

This study aims to review current laboratory reporting strategies across Australia and New Zealand with a view to propose a more useful template for reporting serum testosterone in the context of prostate cancer.

MATERIALS AND METHODS

Registered pathology laboratories in Australia and New Zealand were enrolled into the current study. An electronic or a phone survey was utilized to collect data from each participating laboratory. Obtained information included assay utilized, units reported, reference intervals, lowest reported value, and lowest detectable value. To identify recommendations for testosterone testing, a systematic search was performed across Web of Science (including MEDLINE), EMBASE, and Cochrane libraries.

RESULTS

Assessment of national pathology laboratories identified significant heterogeneity in the reporting methods. Reports typically used a "normal healthy male of 35 years of age" as a comparator but did not refer to optimal castrate levels, the lowest level that their assay was able to detect, nor did they include appended clinical guidelines relating to the prostate cancer patient cohort.

CONCLUSIONS

Across Australia and New Zealand, various methods for testing and reporting serum testosterone exist, while international guidelines remain vague. The fashion in which serum testosterone levels are displayed should be re-evaluated to address the relevant clinical population and reflect an agreed-upon castrate threshold in patients undergoing androgen deprivation therapy.