Goserelin versus orchiectomy in the treatment of advanced prostate cancer: final results of a randomized trial. Zoladex Prostate Study Group

Prostate Cancer, Race, and Health Disparity: What We Know

ABSTRACT

Prostate cancer (PCa) in African American men is one of the most common cancers with a great disparity in outcomes. The higher incidence and tendency to present with more advanced disease have prompted investigators to postulate that this is a problem of innate biology. However, unequal access to health care and poorer quality of care raise questions about the relative importance of genetics versus social/health injustice. Although race is inconsistent with global human genetic diversity, we need to understand the sociocultural reality that race and racism impact biology. Genetic studies reveal enrichment of PCa risk alleles in populations of West African descent and population-level differences in tumor immunology. Structural racism may explain some of the differences previously reported in PCa clinical outcomes; fortunately, there is high-level evidence that when care is comparable, outcomes are comparable.

Luteinizing hormone-releasing hormone agonists versus orchiectomy in the treatment of prostate cancer: A systematic review

BACKGROUND

Orchiectomy has been replaced by medication represented by luteinizing hormone-releasing hormone (LHRH) agonist as the first-line therapy for androgen deprivation therapy (ADT). After the wide application of LHRH agonist, the side-effects of long-term ADT were noticed. It is time to reconsider the role of medication and surgeries in the treatment of prostate cancer.

METHODS

Embase, Pubmed, Web of science and Cochrane library were searched for relevant trials. Quality of the studies and risk of bias were assessed by using the Newcastle-Ottawa Scale (NOS). Therapeutic and adverse effects, as well as long-term metabolic adverse effects were extracted from the selected studies. The data synthesized in meta-analyses were performed with R software (4.2.1). Risk ratio (RR) with its 95% confidence interval (CI) was calculated by combining outcome data including complete and partial response rate, progression rate, death rate and adverse effects such as hot flash and increase in pain. Descriptive analysis was performed among the prostate specific antigen (PSA), testosterone and metabolic adverse effects due to a lack of homogeneity of frailty measures.

RESULTS

1,711 participants from 11 studies were included in our systematic review. 1,258 patients from six studies were included in the meta-analysis. Based on the meta-analysis, the therapeutic and adverse outcomes included overall response rate, complete response rate, partial response rate, stable rate, progression rate, death rate and hot flashes. No statistical significance was observed between LHRH agonists and orchiectomy. Compared with surgery, LHRH agonist elevated the risk of the increase in pain. In descriptive analysis, it was shown that the therapeutic effects between PSA and testosterone also showed no significant difference. Both groups had lipid and glucose metabolic disorders, and a few studies reported worse lipid metabolic performance in orchiectomy group and worse insulin resistance in LHRH agonist group.

CONCLUSION

We found that the therapeutic outcomes were similar between the two options. The results of lipid and glucose metabolic abnormality were controversial in existing studies. The direct comparison studies on metabolic adverse effects should be performed in the future. The therapeutic, metabolic, psychological and economical effects should be considered before applying ADT methods.

SYSTEMATIC REVIEW REGISTRATION

https://www.crd.york.ac.uk/prospero/, identifier CRD42022365891.

Design, Synthesis and Cytotoxicity Evaluation of Novel Indole Derivatives Containing Benzoic Acid Group as Potential AKR1C3 Inhibitors

Castration-resistant prostate cancer (CRPC) is a fatal, metastatic form of prostate cancer, characterized by reactivation of the androgen axis. Aldo-keto reductase 1C3 (AKR1C3) converts androstenedione (AD) and 5α-androstanedione to testosterone (T) and 5α-dihydrotestosterone (DHT), respectively. In CRPC, AKR1C3 is upregulated and implicated in drug resistance and has been regarded as a potential therapeutic target. Here we examined a series of indole derivatives containing benzoic acid or phenylhydroxamic acid and found that 4-({3-[(3,4,5-trimethoxyphenyl)sulfanyl]-1H-indol-1-yl}methyl)benzoic acid (3e) and N-hydroxy-4-({3-[(3,4,5-trimethoxyphenyl)sulfanyl]-1H-indol-1-yl}methyl)benzamide (3q) inhibited 22Rv1 cell proliferation with IC₅₀ values of 6.37 μM and 2.72 μM, respectively. In enzymatic assay, compounds 3e and 3q exhibited potent inhibitory effect against AKR1C3 (IC₅₀ =0.26 and 2.39 μM, respectively). These results indicated that compounds 3e and 3q might be useful leads for further investigation of more potential AKR1C3 inhibitors used for CRPC.

Peptide-Based Therapeutics for Oncology

The development of peptide-based drugs, which are usually synthetic analogues of endogenous peptides, is currently one of the most topical directions in drug development. Among them, antitumor peptide-based drugs are of great interest. Anticancer peptides can be classified into three main groups based on their mechanism of action: inhibitory, necrosis-inducing and pro-apoptotic peptides. As an antitumor therapy, peptides are considered to have at least the same efficacy as chemotherapy or surgical treatment, but offer advantages in terms of safety and tolerability, given that chemotherapy is usually characterized by severe adverse effects, and surgery carries additional risks for patients. Short peptides have a number of benefits over other molecules. First, compared with full-length proteins and antibodies, short peptides are less immunogenic, more stable ex-vivo (prolonged storage at room temperature), and have better tumor or organ permeability. Moreover, the production of such short peptide-based drugs is more cost effective. Second, in comparison with small organic molecules, peptides have higher efficacy and specificity. Finally, due to the fact that the main products of peptide metabolism are amino acids, these drugs are usually characterized by lower toxicity. Short peptides have a highly selective mechanism of action, thereby demonstrating low toxicity. Furthermore, with the addition of different stabilizing structural modifications, as well as novel drug delivery systems, the peptide-based drugs are proving to be promising therapeutics for cancer mono- or polytherapy. However, challenges remain including that endogenous and synthetic peptide molecules can be oncogenic. Therefore, it is important to investigate whether peptides contribute to tumor growth. In order to answer such questions, numerous preclinical and clinical studies of peptide-based therapeutics are currently being conducted.

Utilization and Outcomes of Surgical Castration in Comparison to Medical Castration in Metastatic Prostate Cancer

Androgen deprivation therapy is the gold standard for metastatic prostate cancer, which can be achieved either by surgical or medical castration. In this study of 33,585 patients in the National Cancer Database, there was significant decline in the trend of utilization of surgical castration from 8.6% in 2004 to 3.1% in 2014. However, there was no survival difference with surgical castration when compared with medical castration. Increasing the utilization of surgical castration could help reduce health care expenditures. Patients and physicians need to be aware of treatment options and their financial implications.

AKR1C3 Inhibitor KV-37 Exhibits Antineoplastic Effects and Potentiates Enzalutamide in Combination Therapy in Prostate Adenocarcinoma Cells

Aldo-keto reductase 1C3 (AKR1C3), also known as type 5 17 β-hydroxysteroid dehydrogenase, is responsible for intratumoral androgen biosynthesis, contributing to the development of castration-resistant prostate cancer (CRPC) and eventual chemotherapeutic failure. Significant upregulation of AKR1C3 is observed in CRPC patient samples and derived CRPC cell lines. As AKR1C3 is a downstream steroidogenic enzyme synthesizing intratumoral testosterone (T) and 5α-dihydrotestosterone (DHT), the enzyme represents a promising therapeutic target to manage CRPC and combat the emergence of resistance to clinically employed androgen deprivation therapy. Herein, we demonstrate the antineoplastic activity of a potent, isoform-selective and hydrolytically stable AKR1C3 inhibitor (E)-3-(4-(3-methylbut-2-en-1-yl)-3-(3-phenylpropanamido)phenyl)acrylic acid (KV-37), which reduces prostate cancer cell growth in vitro and in vivo and sensitizes CRPC cell lines (22Rv1 and LNCaP1C3) toward the antitumor effects of enzalutamide. Crucially, KV-37 does not induce toxicity in nonmalignant WPMY-1 prostate cells nor does it induce weight loss in mouse xenografts. Moreover, KV-37 reduces androgen receptor (AR) transactivation and prostate-specific antigen expression levels in CRPC cell lines indicative of a therapeutic effect in prostate cancer. Combination studies of KV-37 with enzalutamide reveal a very high degree of synergistic drug interaction that induces significant reduction in prostate cancer cell viability via apoptosis, resulting in >200-fold potentiation of enzalutamide action in drug-resistant 22Rv1 cells. These results demonstrate a promising therapeutic strategy for the treatment of drug-resistant CRPC that invariably develops in prostate cancer patients following initial treatment with AR antagonists such as enzalutamide. Mol Cancer Ther; 17(9); 1833-45. ©2018 AACR.

Prognosis of prostate cancer with initial prostate-specific antigen >1,000 ng/mL at diagnosis

PURPOSE

Prostate cancer patients with surprisingly high prostate-specific antigen (PSA) are encountered clinically. However, descriptions of this group of patients are extremely rare in the published literature. This study reports treatment outcome and long-term prognosis for this group of patients.

PATIENTS AND METHODS

Between January 2007 and December 2012, 2,064 patients with PCa diagnosed at a tertiary medical center were retrospectively reviewed. A total of 90 PCa cases were identified with initial PSA (iPSA) >1,000 ng/mL at diagnosis. A retrospective study was conducted in this cohort, with comparison among stratified patient age groups, PSA, treatment options, and overall survival.

RESULTS

The mean PSA at PCa diagnosis in this cohort was 3,323 ng/mL (1,003-23,126, median: 2,050 ng/mL). Most patients were in the age group 65-79 years (55/90, 61%). Males older than 80 years had a poor prognosis (P<0.001). Forty-six patients (51%) underwent orchiectomy with a median follow-up period of 16.2 (1.3-72.7) months, compared to 44 patients treated with medical castration and a median follow-up of 9.1 (0.3-70.5) months. Kaplan-Meier analysis revealed survival benefit from treatment with orchiectomy (P<0.001). PSA reduction >90% of iPSA following primary androgen deprivation therapy (reaching true nadir) could be a predictor of longer survival (P<0.001). Cox regression revealed the hazard ratio (HR) of variables were age (HR: 4.57, 95% confidence interval [CI]: 1.45-14.37, P=0.009), reaching true nadir (HR: 0.12, 95% CI: 0.03-0.58, P=0.008), and the treatment option with orchiectomy (HR: 0.22, 95% CI: 0.65-0.76, P=0.016).

CONCLUSION

Age ≥80 years indicated poor overall survival in PCa patients with iPSA >1,000 ng/mL. Reaching a true nadir of PSA following primary androgen deprivation therapy could be a predictor of longer survival. Bilateral orchiectomy is recommended for this group of patients.

Testosterone monitoring for men with advanced prostate cancer: Review of current practices and a survey of Canadian physicians

Androgen-deprivation therapy (ADT) is a standard of care in the treatment of advanced prostate cancer; however, testosterone monitoring practices for men undergoing ADT vary across Canada. Although a testosterone level of 1.7 nmol/L or lower has historically been defined as the accepted castrate level, newer assays with improved sensitivity have shown that both medical and surgical castration can suppress testosterone levels to below 0.7 nmol/L. This review explores the evidence supporting a redefinition of the castrate testosterone level as 0.7 nmol/L or lower, and presents results of a survey of testosterone monitoring practices among 153 Canadian urologists, uro-oncologists, and radiation oncologists who manage the treatment of men with hormone-sensitive prostate cancer.

Luteinizing Hormone-Releasing Hormone Agonists are Superior to Subcapsular Orchiectomy in Lowering Testosterone Levels of Men with Prostate Cancer: Results from a Randomized Clinical Trial

PURPOSE

Recent evidence suggests that reaching the lowest achievable levels of testosterone with androgen deprivation therapy delays disease progression and increases overall survival in men with advanced prostate cancer. The aim of this analysis was to compare posttreatment serum testosterone levels between patients undergoing subcapsular orchiectomy and patients treated with the luteinizing hormone-releasing hormone agonist triptorelin.

MATERIALS AND METHODS

In this randomized clinical trial we included 58 consecutive hormone naïve men diagnosed with advanced prostate cancer at Herlev and Gentofte University Hospital, Herlev, Denmark from September 2013 to March 2015. Followup was 48 weeks. Participants were randomly assigned 1:1 to subcapsular orchiectomy or triptorelin 22.5 mg given as 24-week depot injections. Androgen status was measured by liquid chromatography-tandem mass spectrometry prior to treatment and after 12, 24 and 48 weeks. Between group differences in achieved hormone levels were analyzed by longitudinal Tobit regression.

RESULTS

Triptorelin injections resulted in 29% lower testosterone levels (95% CI 17.2-41.7) compared to subcapsular orchiectomy (p <0.001). A significantly higher proportion of men receiving triptorelin had testosterone levels less than 20 ng/dl at 12 and 48 weeks compared to men undergoing orchiectomy (97% vs 79% and 100% vs 87%, respectively, p <0.05). There was no detectable difference in the adrenal androgen reduction between the treatment groups.

CONCLUSIONS

The use of 24-week depot triptorelin injections results in significantly lower testosterone levels compared to subcapsular orchiectomy. To our knowledge this is the first randomized study to demonstrate a difference in treatment effect between surgical and medical castration on testosterone levels.

Efficacy of switching therapy of luteinizing hormone-releasing hormone analogue for advanced prostate cancer

This study was conducted to determine the efficacy of switching therapy with a second-line luteinizing hormone-releasing hormone (LHRH) analogue after prostate-specific antigen (PSA) progression for advanced prostate cancer. We enrolled 200 patients, from December 2005 to September 2013, with nodal positive, metastatic prostate cancer or disease progression after definite treatment receiving continuous LHRH analogue therapy with monthly depot leuprorelin(sc) acetate 3.75 mg/vial (LA) or goserelin acetate(sc) 3.6 mg/vial (GA). If the patients had castration-resistant prostate cancer, the treatment choice of switching therapy (from LA to GA or from GA to LA) prior to starting chemotherapy was given. The LH, testosterone level, and PSA change were recorded. The records showed that there were 127 patients receiving LA as initial ADT therapy, whereas the other 73 patients were in GA therapy. A total of 92 patients received LHRH analogue switching therapy (54 patients switched from LA to GA and 38 switched from GA to LA). The effect of LH and testosterone reduction prior to and after switching therapy was comparable between the two groups, and increased PSA level after 3 months of treatment was seen in both groups (median PSA: 15.7-67.7 ng/mL in the LA to GA group; 15.2-71.4 ng/mL in the GA to LA group). This study concluded that switching therapy for patients with PSA progression after ADT has no efficacy of further PSA response.

Evidence-based recommendations on androgen deprivation therapy for localized and advanced prostate cancer

INTRODUCTION

The management of prostate cancer (PC) is still evolving. Although, androgen deprivation therapy (ADT) is an established treatment option, particularly in patients with disseminated disease, important data regarding hormonal manipulation have recently emerged. The aim of this paper is to review the evidence on ADT, make recommendations and address areas of controversy associated with its use in men with PC.

MATERIAL AND METHODS

An expert panel was convened. Areas related to the hormonal management of patients with PC requiring evidence review were identified and questions to be addressed by the panel were determined. Appropriate literature review was performed and included a search of online databases, bibliographic reviews and consultation with experts.

RESULTS

The panel was able to provide recommendations on: 1) which patients with localised PC should receive androgen deprivation in conjunction with radiotherapy (RT); 2) what standard initial treatment should be used in metastatic hormone-naïve PC (MHNPC); 3) efficacy of androgen deprivation agents; 4) whether ADT should be continued in patients with castration resistant PC (CRPC). However, no recommendations could be made for combined ADT and very high-dose RT in patients with an intermediate-risk disease.

CONCLUSIONS

ADT remains the cornerstone of treatment for both metastatic hormone-naïve and castration-resistant PC. According to the expert panel's opinion, based on the ERG report, luteinizing hormone-releasing hormone agonists might not be equivalent but this needs to be confirmed in long-term data. The combined use of ADT and RT improves outcome and survival in men with high-risk localised disease. The benefits in patients with intermediate-risk disease, particularly those subject to escalated dose RT are controversial.

Mortality, cardiovascular risk, and androgen deprivation therapy for prostate cancer: A systematic review with direct and network meta-analyses of randomized controlled trials and observational studies

Androgen deprivation therapy (ADT) is a cornerstone therapy for advanced prostate cancer (PCa). We hypothesized that cardiovascular (CV) risk is different across the various ADT modalities to compare their effects on CV morbidity and mortality, and all-cause mortality in patients with PCa. To investigate more in depth potential CV risk heterogeneity focusing on coronary (main outcome) and cerebrovascular risk, CV, and overall mortality. We performed a Medline and Embase query, without language restriction, since 1950 up to July 2014. We included randomized controlled trials (RCTs) and observational studies providing that they compared at least 1 ADT modality to another one or to placebo and they gave data on CV event or all-cause mortality. Sixty-eight studies out of 3419 met our eligibility criteria. Eleven observational studies were analyzed. Direct meta-analyses showed that antiandrogen was associated with a 30% decrease risk for myocardial infarction (MI) compared to GnRH agonists (RR, 0.70 [0.54-0.91]); combined androgen blockade (CAB) was associated with a 10% increase risk for stroke when compared to antiandrogen (RR, 1.10 [1.02-1.19]). With regard to RCTs, 57 were included: direct meta-analyses suggested that CAB was associated with a 10% decrease of all-cause mortality when compared to GnRH agonist (RR, 0.90 [0.82-1.00]). Network analysis could only be performed for all-cause mortality and it remains difficult to disentangle benefit (positive impact on cancer survival) and risk (including CV risk). The impact of the ADT modalities on CV morbidity remains difficult to quantify and more detailed prospective collection is required.

REGISTRATION

PROSPERO, CRD42014010598.

Surgical castration efficiently delays the time of starting a systemic chemotherapy in castration-resistant prostate cancer patients refractory to initial androgen-deprivation therapy

Background

The aim of this study was to investigate the effects of surgical castration, particularly delaying the time to entrance of systemic chemotherapy, in castration-resistant prostate cancer (CRPC) patients who were refractory to initial combination androgen deprivation therapy.

Materials and methods

We analyzed the clinical data of 14 CRPC patients diagnosed at Seoul National University Bundang Hospital (SNUBH) from November 2008 through May 2015. After exclusion of three patients, we finally analyzed the baseline characteristics of 11 CRPC patients. We also assessed the delaying time of docetaxel administration, which was defined as response duration, after surgical castration.

Results

After bilateral orchiectomy, the treatment response rate was 45.4% and the median duration of response was 9 months (range 4–48 mo). Responders had less aggressive biopsy Gleason scores compared to nonresponders. Notably, responders showed the reducing pattern of serum prostate specific antigen levels, while nonresponders demonstrated increasing tendency after surgical castration. Moreover, responders also presented with a reduction pattern of serum testosterone levels, whereas nonresponders showed an increasing pattern of testosterone levels after bilateral orchiectomy.

Conclusions

In summary, despite the limited number of cases for convincing evidence, our results shed light again on the clinical benefits of surgical castration prior to the systemic chemotherapy in some CRPC patients after initial hormone therapy.

Risk of new-onset diabetes after androgen deprivation therapy for prostate cancer in the Asian population

BACKGROUND

The associations of androgen deprivation therapy (ADT) with its adverse events in the Asian population remained largely unknown. We investigated the risk of new-onset diabetes mellitus (DM) after ADT for prostate cancer in the Asian population.

METHODS

All prostate cancer patients who were treated primarily with radical prostatectomy or radiotherapy, with or without further ADT from 2000 to 2009 were reviewed. Clinical parameters including age, clinical T stage, Gleason score, hypertension, dyslipidemia, impaired fasting glucose, ischemic heart disease, history of stroke, new-onset DM, follow-up duration, form and duration of ADT were reviewed. The risk of DM after ADT was analyzed with Kaplan-Meier method and multivariate Cox regression analysis.

RESULTS

A total of 388 patients were included, consisting of 169 patients in the non-ADT group and 219 patients in the ADT group. Upon Kaplan-Meier analysis, the ADT group had a higher risk of new-onset DM (P = 0.011). Upon multivariate Cox regression analysis, dyslipidemia (HR 2.32, 95% CI 1.07-5.00, P = 0.032), impaired fasting glucose (HR 5.92, 95% CI 1. 2.27-15.45, P < 0.001) and the use of ADT in the form of GnRH agonist (HR 3.34, 95% CI 1.19-9.39, P = 0.022) and bilateral orchiectomy (HR 6.49, 95% CI 1.48-28.55, P = 0.013) were associated with increased risk of new-onset DM.

CONCLUSIONS

There was increased risk of new-onset DM after ADT for prostate cancer in the Asian population. Regular screening of DM can be considered after the initiation of ADT, especially in patients with known history of dyslipidemia and impaired fasting glucose.

Management of patients with advanced prostate cancer: recommendations of the St Gallen Advanced Prostate Cancer Consensus Conference (APCCC) 2015

The first St Gallen Advanced Prostate Cancer Consensus Conference (APCCC) Expert Panel identified and reviewed the available evidence for the ten most important areas of controversy in advanced prostate cancer (APC) management. The successful registration of several drugs for castration-resistant prostate cancer and the recent studies of chemo-hormonal therapy in men with castration-naïve prostate cancer have led to considerable uncertainty as to the best treatment choices, sequence of treatment options and appropriate patient selection. Management recommendations based on expert opinion, and not based on a critical review of the available evidence, are presented. The various recommendations carried differing degrees of support, as reflected in the wording of the article text and in the detailed voting results recorded in supplementary Material, available at Annals of Oncology online. Detailed decisions on treatment as always will involve consideration of disease extent and location, prior treatments, host factors, patient preferences as well as logistical and economic constraints. Inclusion of men with APC in clinical trials should be encouraged.

Risk of cardiovascular thrombotic events after surgical castration versus gonadotropin-releasing hormone agonists in Chinese men with prostate cancer

We investigated the cardiovascular thrombotic risk after surgical castration (SC) versus gonadotropin-releasing hormone agonists (GnRHa) in Chinese men with prostate cancer. All Chinese prostate cancer patients who were treated with SC or GnRHa from year 2000 to 2009 were reviewed and compared. The primary outcome was any new-onset of cardiovascular thrombotic events after SC or GnRHa, which was defined as any event of acute myocardial infarction or ischemic stroke. The risk of new-onset cardiovascular thrombotic event was compared between the SC group and the GnRHa group using Kaplan-Meier method. Multivariate Cox regression analysis was performed to adjust for other potential confounding factors. A total of 684 Chinese patients was included in our study, including 387 patients in the SC group and 297 patients in the GnRHa group. The mean age in the SC group (75.3 ± 7.5 years) was significantly higher than the GnRHa group (71.8 ± 8.3 years) (P < 0.001). There was increased risk of new cardiovascular thrombotic events in the SC group when compared to the GnRHa group upon Kaplan-Meier analysis (P = 0.014). Upon multivariate Cox regression analysis, age (hazard ratio [HR] 1.072, 95% confidence interval [CI] 1.04-1.11, P< 0.001), hyperlipidemia (HR 2.455, 95% CI 1.53-3.93, P< 0.001), and SC (HR 1.648, 95% CI 1.05-2.59, P= 0.031) were significant risk factors of cardiovascular thrombotic events. In conclusion, SC was associated with increased risk of cardiovascular thrombotic events when compared to GnRHa. This is an important aspect to consider while deciding on the method of androgen deprivation therapy, especially in elderly men with known history of hyperlipidemia.

Androgen receptor antagonists for prostate cancer therapy

Androgen deprivation is the mainstay therapy for metastatic prostate cancer (PCa). Another way of suppressing androgen receptor (AR) signaling is via AR antagonists or antiandrogens. Despite being frequently prescribed in clinical practice, there is conflicting evidence concerning the role of AR antagonists in the management of PCa. In the castration-resistant settings of PCa, docetaxel has been the only treatment option for decades. With recent evidence that castration-resistant PCa is far from AR-independent, there has been an increasing interest in developing new AR antagonists. This review gives a concise overview of the clinically available antiandrogens and the experimental AR antagonists that tackle androgen action with a different approach.

The role of single nucleotide polymorphisms in predicting prostate cancer risk and therapeutic decision making

Prostate cancer (PCa) is a major health care problem because of its high prevalence, health-related costs, and mortality. Epidemiological studies have suggested an important role of genetics in PCa development. Because of this, an increasing number of single nucleotide polymorphisms (SNPs) had been suggested to be implicated in the development and progression of PCa. While individual SNPs are only moderately associated with PCa risk, in combination, they have a stronger, dose-dependent association, currently explaining 30% of PCa familial risk. This review aims to give a brief overview of studies in which the possible role of genetic variants was investigated in clinical settings. We will highlight the major research questions in the translation of SNP identification into clinical practice.

Serum testosterone levels after medical or surgical androgen deprivation: a comprehensive review of the literature

Androgens and the androgen receptor play a role in the progression of prostate cancer. Androgen deprivation therapy (ADT) is a mainstay in the treatment of metastatic prostate cancer. ADT is expected to reduce serum testosterone levels from a normal level of about 500 to 600 ng/dl (17.3-20.8 nmol) down to castration levels. Traditionally, castration was considered to be achieved if testosterone levels were lowered to a threshold of 50 ng/dl (1.73 nmol/l), a definition determined more by measurement methods derived from the use of old assay methods than by evidence. Serum testosterone levels in three-quarter patients after surgical castration drop to less than 20 ng/dl (0.69 nmol/l). Ineffective suppression of testosterone is currently poorly recognized and may possibly have an effect of prostate cancer mortality. Persistent levels of serum testosterone after castration are mainly derived from adrenal androgens. Furthermore, the arrival of new therapies targeting androgen synthesis and androgen receptor activity has renewed interest on serum testosterone. This review discusses the biosynthetic pathway for androgen synthesis in humans and provides a comprehensive review of serum testosterone levels after surgical or medical castration. This review assesses serum testosterone levels after surgical castration and different pharmacologic castration in patients with prostate cancer under ADT, and ineffective testosterone suppression. The author proposes methods to better lower serum testosterone levels during ADT.

Clinical significance of suboptimal hormonal levels in men with prostate cancer treated with LHRH agonists

PURPOSE

We examined the serum levels of testosterone (T) (total and bioavailable) dehydroepiandrosterone (DHEA), follicle-stimulating hormone (FSH), luteinizing hormone (LH), and prostate-specific antigen (PSA) in men receiving treatment with luteinizing hormone releasing-hormone (LHRH) agonists for metastatic prostate cancer. In doing this, we want to determine the efficacy of these agents in lowering T levels and whether a possible relationship exists between PSA values, as a surrogate measure of tumour activity, and hormone levels.

METHODS

This was a single centre prospective study of patients on LHRH agonists. Of all the 100 eligible patients, 31 did not qualify (10 were receiving their first injection, 13 were on intermittent hormonal therapy, 7 refused to enter the trial and 1 patient's blood sample was lost). Therefore in total, 69 patients were included in the final analysis. Each patient had their blood sample drawn immediately before the administration of a LHRH agonist. The new proposed criteria of <20 ng/dL (0.69 nmol/L) of total testosterone was used to define optimal levels of the hormone in this population.

RESULTS

Of the 69 patients, 41 were on goserelin injections, 21 on leuprolide, and 7 on buserelin. There was no statistical difference in hormone levels between any of the medications. Overall, 21% of patients failed to reach optimal levels of total testosterone. PSA levels were higher in this group. There was a statistically significant correlation between PSA and testosterone levels, as well as between PSA and FSH. Serum levels of PSA, however, did not correlate with those of bioavailable testosterone.

CONCLUSIONS

Failure to reach optimal levels of testosterone occurs in patients on LHRH agonist therapy. Higher PSA values are more commonly found in patients with suboptimal levels of testosterone receiving LHRH analogs, but the clinical importance of this finding has not been established. There is no significant difference with respect to hormonal levels reached among patients on a variety of LHRH agonists. Total testosterone determinations should be considered in patients on LHRH agonist therapy, particularly when the PSA values begin to rise since it may lead to further beneficial hormonal manipulation.

Overcoming drug resistance and treating advanced prostate cancer

Most of the prostate cancers (PCa) in advanced stage will progress to castration-resistant prostate cancer (CRPC). Within CRPC group, 50-70% of the patients will develop bone metastasis in axial and other regions of the skeleton. Once PCa cells spread to the bone, currently, no treatment regimens are available to eradicate the metastasis, and cancer-related death becomes inevitable. In 2012, it is estimated that there will be 28,170 PCa deaths in the United States. Thus, PCa bone metastasis-associated clinical complications and treatment resistance pose major clinical challenges. In this review, we will present recent findings on the molecular and cellular pathways that are responsible for bone metastasis of PCa. We will address several novel mechanisms with a focus on the role of bone and bone marrow microenvironment in promoting PCa metastasis, and will further discuss why prostate cancer cells preferentially metastasize to the bone. Additionally, we will discuss novel roles of several key pathways, including angiogenesis and extracellular matrix remodeling in bone marrow and stem cell niches with their relationship to PCa bone metastasis and poor treatment response. We will evaluate how various chemotherapeutic drugs and radiation therapies may allow aggressive PCa cells to gain advantageous mutations leading to increased survival and rendering the cancer cells to become resistant to treatment. The novel concept relating several key survival and invasion signaling pathways to stem cell niches and treatment resistance will be reviewed. Lastly, we will provide an update of several recently developed novel drug candidates that target metastatic cancer microenvironments or niches, and discuss the advantages and significance provided by such therapeutic approaches in pursuit of overcoming drug resistance and treating advanced PCa.

The effect of baseline testosterone on the efficacy of degarelix and leuprolide: further insights from a 12-month, comparative, phase III study in prostate cancer patients

OBJECTIVE

To investigate the effects of baseline testosterone on testosterone control and prostate-specific antigen (PSA) suppression using data from a phase III trial (CS21) comparing degarelix and leuprolide in prostate cancer.

METHODS

In CS21, patients with histologically confirmed prostate cancer (all stages) were randomized to degarelix 240 mg for 1 month followed by monthly maintenance doses of 80 or 160 mg, or leuprolide 7.5 mg/month. Patients receiving leuprolide could receive antiandrogens for flare protection. Treatment effects on testosterone and PSA reduction, testosterone surge, and microsurges were investigated in 3 baseline testosterone subgroups: <3.5, 3.5-5.0, and >5.0 ng/mL. Data are presented for the groups receiving degarelix 240/80 mg (the approved dose) and leuprolide 7.5 mg.

RESULTS

Higher baseline testosterone delayed castration with both treatments. However, castrate testosterone levels and PSA suppression occurred more rapidly with degarelix irrespective of baseline testosterone. With leuprolide, the magnitude of testosterone surge and microsurges increased with increasing baseline testosterone. There was no overall correlation between baseline testosterone and initial PSA decrease in either treatment group, although PSA suppression tended to be slowest with leuprolide and fastest with degarelix in the high baseline testosterone subgroup.

CONCLUSION

Patients with high baseline testosterone may have greater risk of tumor stimulation (clinical flare) and mini-flares during gonadotrophin-releasing hormone agonist treatment and so the need for flare protection with antiandrogens in these patients is obvious, especially in metastatic disease. Although higher baseline testosterone delays castration, castrate testosterone and PSA suppression occur more rapidly with degarelix, irrespective of baseline testosterone, without the need for flare protection.

Variations of serum testosterone levels in prostate cancer patients under LH-releasing hormone therapy: an open question

The hypothesis 'the lower the better when achieving castration levels of testosterone' is based on the data from second-line hormonal manipulation and its molecular basis, and on better oncological results reported for lower castration levels in prostate cancer (PCa) patients, including those achieved with maximal androgen blockade. In this regard, the equivalence of surgical and different pharmacological castrations has been controversial. The modified amino acid structure that makes LH-releasing hormone (LHRH) analogs more potent than LHRH, and the method of delivering the analogs impacts on bioavailibility and potentially causes differences in androgen levels and in its final oncological efficacy. In addition to this, there is a myriad of circumstances, such as those related to ethnic variations and co-morbidities, which uniquely impact on the pharmacological approach in a highly heterogeneous population of castration-resistant prostate cancer (CRPC) patients. Ineffective testosterone suppression through hormonal escape is currently poorly recognized and may result in increased PCa mortality. Until now, the optimal serum testosterone level in patients under castration, and the impact of its variations in patients under LHRH therapy, remain open questions and have been merged to a broad spectra of patients who are highly heterogeneous. This heterogeneity relates to a number of mechanisms regarding response to treatment, which influences the biology of the relapsing tumor and the sensitivity to subsequent therapies in the individual patient. The rationale to achieve testosterone levels below 20-50 ng/dl warrant further investigation as these levels have recently rescued CRPC patients. In the last few years and months, important advancements in prostate cancer treatment have been achieved. Nevertheless, these advances are measured in a few months of additional survival and under high costs, not available to most of the world population, compared with the benefits of hormonal manipulation that are measured in years, there is a huge potential for accessible and durable effect expansion and optimization of treatment, particularly with the current tendency of a more individual approach.

Lower testosterone levels with luteinizing hormone-releasing hormone agonist therapy than with surgical castration: new insights attained by mass spectrometry

PURPOSE

Androgen deprivation therapy by bilateral orchiectomy (surgical castration) or luteinizing hormone-releasing hormone agonist therapy (medical castration) is recommended for advanced or metastatic prostate cancer. Both methods aim at reducing serum testosterone concentrations to a castrate level which is currently defined as less than 50 ng/dl. The results of previous studies are based on testosterone immunoassays that have insufficient accuracy in the low range. In this study we reevaluated serum testosterone concentrations in men on androgen deprivation therapy using isotope dilution-liquid chromatography-tandem mass spectrometry, an accurate method of measuring testosterone in the castrate range.

MATERIALS AND METHODS

Subjects underwent surgical castration (34) or received a luteinizing hormone-releasing hormone agonist (32). Serum samples were obtained more than 3 months after surgery or initiation of luteinizing hormone-releasing hormone agonist therapy. Testosterone levels were determined using isotope dilution-liquid chromatography-tandem mass spectrometry. Dihydroepiandrosterone sulfate, androstenedione, sex hormone-binding globulin and inhibin B levels were determined.

RESULTS

All subjects had serum testosterone values less than 50 ng/dl and 97% had testosterone concentrations less than 20 ng/dl. Medically castrated men had significantly lower testosterone levels (median 4.0 ng/dl, range less than 2.9 to 20.2) than those surgically castrated (median 9.2 ng/dl, range less than 2.9 to 28.8, p <0.001). No difference was found in dehydroepiandrosterone sulfate, androstenedione and sex hormone-binding globulin levels between the groups, whereas inhibin B levels were significantly higher in the luteinizing hormone-releasing hormone agonist treated group.

CONCLUSIONS

Using an accurate technique for testosterone measurement, subjects on luteinizing hormone-releasing hormone agonist therapy had significantly lower testosterone concentrations than men who underwent surgical castration. The clinical relevance of these findings remains to be determined.

Efficacy and safety of gonadotropin-releasing hormone agonists used in the treatment of prostate cancer

Androgen deprivation therapy (ADT) is the most effective systemic treatment for prostate cancer. ADT has been shown to have a high rate of response and to improve overall survival in patients with metastatic prostate cancer. In addition, multiple studies have shown that adding ADT to external beam radiation therapy leads to improvement in cure rates and overall survival in prostate cancer patients. The most commonly used ADT is gonadotropin-releasing hormone (GnRH) agonist therapy. Although GnRH agonist therapy has significant benefits for patients with prostate cancer, it has also been shown to have significant side effects, including fatigue, hot flashes, decreased libido, decreased quality of life, obesity, diabetes mellitus, coronary artery disease, decreased bone mineral density, and increased risk of fractures. Therefore, it is crucial that the benefits of ADT be weighed against its potential adverse effects before its use.

Risk stratification in the hormonal treatment of patients with prostate cancer

Prostate cancer (PCa) is the most common type of cancer found in American men, other than skin cancer. The American Cancer Society estimates that there will be 186,320 new cases of prostate cancer in the United States in 2008. About 28,660 men will die of this disease this year and PCa remains the second-leading cause of cancer death in men. One in six men will get PCa during his lifetime and one in 35 will die of the disease. Today, more than 2 million men in the United States who have had PCa are still alive. The death rate for PCa continues to decline, chiefly due to early detection and treatment, and improved salvage therapy such as hormone therapy (HT). HT continues to be a mainstay for primary-recurrent PCa and locally-advanced PCa. However, HT is associated with many undesirable side effects including sexual dysfunction, osteoporosis and hot flashes, all of which can lead to decreased quality of life (QOL). These risks are seen in both long- and short-term HT regimens. Additionally, research in recent years has revealed trends related to clinico pathological variables and their predictive ability in HT outcomes. Awareness of the potential adverse effects, the risks associated with HT and the prognostic ability of clinical and pathological variables is important in determining optimal therapy for individual patients. A rigorous evaluation of the current scientific literature associated with HT was conducted with the goal of identifying the most favorable balance of benefits and risks associated with HT.

Six-month gonadotropin releasing hormone (GnRH) agonist depots provide efficacy, safety, convenience, and comfort

Two different 6-month GnRH agonist depot formulations approved for palliative treatment of advanced and metastatic prostate cancer in the United States - leuprolide acetate 45 mg and triptorelin pamoate 22.5 mg - provide patients with efficacy and safety comparable to those of existing 1-, 3-, and 4-month GnRH agonist depots. However, the 6-month formulations can increase patient convenience, comfort, and compliance by reducing the number of physician visits and injections required. At the conclusion of their pivotal trials, the 6-month formulations demonstrated efficacy rates in achieving chemical castration (serum testosterone ≤50 ng/dL) that ranged between 93% and 99%. As with existing GnRH agonist depot formulations, hot flashes represented the most common adverse event reported in trials of 6-month leuprolide acetate or triptorelin. As such, these products may prove useful not only for their labeled indication, but also as adjuncts to other treatments such as radical prostatectomy, radiotherapy, and chemotherapy. We recommend further research, including head-to-head trials between the 6-month GnRH depots, to refine our understanding of these products.

Individualized strategy for dosing luteinizing hormone-releasing hormone agonists for androgen-independent prostate cancer: identification of outcomes and costs

PURPOSE

Continuing androgen suppression is the current standard in men with androgen-independent prostate cancer (AIPC). An individualized strategy, wherein luteinizing hormone-releasing hormone agonists (LH-RHas) are redosed when serum testosterone approaches a non-castrate level, may decrease costs without worsening outcomes. To understand possible outcomes, we performed a cost-utility analysis comparing individualized and fixed LH-RHa dosing strategies in men with AIPC.

METHODS

The model used a societal perspective, a 5-year time horizon, and 3% annual cost discounting. The model accounted for direct costs of androgen suppression. Utilities were varied in accordance with published preference data.

RESULTS

Under base-case assumptions, individualized LH-RHa dosing yielded 1.089 expected quality-adjusted life years (QALYs), compared with 1.094 expected QALYs for fixed LH-RHa dosing. In cost analysis, lifetime per-patient costs for androgen suppression were estimated to be $5,694 for individualized LH-RHa dosing and $9,157 for fixed LH-RHa dosing. Applied to the total population, a strategy of individualized LH-RHa dosing would cost $170 million for androgen suppression, compared with $274 million for fixed LH-RHa dosing. Under these assumptions, adopting the individualized strategy resulted in $692,600 gained from a societal perspective for each QALY lost (the decremental cost utility).

CONCLUSION

The results suggest that an individualized LH-RHa dosing strategy would be associated with moderate savings on an individual basis but substantial savings on a population basis, and would not adversely affect quality of life or life expectancy. Further research is needed to establish the effects of this strategy on symptoms and survival, as well as patient satisfaction and true costs.

Evidence-based medicine: comparative analysis of luteinizing hormone-releasing hormone analogues in combination with external beam radiation and surgery in the treatment of carcinoma of the prostate

What's known on the subject? and What does the study add? Luteinizing hormone-releasing hormone analogues are a cornerstone in the management of many clinical situations in prostate cancer patients. The multiplicity of drugs make it difficult to decide which is the best drug to prescribe to each patient. Whether or not the different luteinizing hormone-releasing hormone analogues belong to the same drug class is only merely supposed. This study adds a systematic review of the literature in order to determine whether or not the luteinizing hormone-releasing hormone analogues available for prescription belong to the same drug class (same family, similar chemical structure, mechanism of action, and efficacy). The current evidence available is not enough to support a presumed drug class effect of the various analogues in the treatment of prostate carcinoma.

OBJECTIVE

• To study whether luteinizing hormone-releasing hormone (LHRH) analogues are agents of the same pharmacological class, i.e. whether they have the same clinical effect, using an evidence-based medicine approach.

MATERIAL AND METHODS

• We reviewed the evidence on the alleged 'drug class effect' among analogues and the existing bibliographic support for their use in various medical indications. We used PubMed as the main search source. Evidence level and degree of recommendation were assigned to each conclusion based on the 'Scottish Intercollegiate Guidelines Network'.

RESULTS

• There are no studies designed to answer the question of class effect between LHRH analogues or agonists. Reviews and meta-analyses have been performed on many other issues related to therapeutic management either with analogues alone, or in combination with radiation therapy and surgery. • Direct comparisons do not allow definitive conclusions to be reached. Indirect evidence is obtained from randomized studies comparing the different LHRH analogues with other treatments used to obtain androgen deprivation. Other issues related to pharmacokinetics and pharmacodynamics that can support either the existence or non-existence of class effect were evaluated.

CONCLUSION

• The current available evidence is not enough to support a presumed class effect of the drug among the different analogues in the treatment of prostate carcinoma in its various clinical situations.

[New perspectives in prostate cancer management]

The treatment of prostate cancer is experiencing important innovations. Hormone therapy includes a new class of drugs: LHRH antagonists, which induce a rapid, fast and sustained reduction of testosterone levels. Active surveillance enables to avoid an aggressive treatment without decreasing survival, provided that strict eligibility and follow-up criteria are applied. New imaging techniques and laboratory assays lead to early diagnosis of small size tumors. Lastly, focal therapy has the potential to target localized cancers without deterioration of surrounding structures. These concomitant improvements offer the clinician and the patient attractive options for prostate cancer management. However, they are not devoid of limitations and constraints. Thus, it is crucial to define the most appropriate patient's profile for each therapeutic option, taking into account the objective characteristics of the tumor and the psychological features of the patient.

Serially heterotransplanted human prostate tumours as an experimental model

* Introduction * Serially heterotransplanted human tumours in immunosuppressed mice: similarity to the tumour of origin - Cytological and histological analysis - Karyotype - Marker expression - Other PC markers - Tumour cell proliferation and frequency of mitosis - Vasculature - Stromal compartment - Heterotransplant hormone dependency - Androgen dependent - Partially androgen dependent - Androgen independent - Metastases * Conclusions Preclinical research on prostate cancer (PC) therapies uses several models to represent the human disease accurately. A common model uses patient prostate tumour biopsies to develop a cell line by serially passaging and subsequent implantation, in immunodeficient mice. An alternative model is direct implantation of patient prostate tumour biopsies into immunodeficient mice, followed by serial passage in vivo. The purpose of this review is to compile data from the more than 30 years of human PC serial heterotransplantation research. Serially heterotransplanted tumours are characterized by evaluating the histopathology of the resulting heterotransplants, including cellular differentiation, karyotype, marker expression, hormone sensitivity, cellular proliferation, metastatic potential and stromal and vascular components. These data are compared with the initial patient tumour specimen and, depending on available information, the patient's clinical outcome was compared with the heterotransplanted tumour. The heterotansplant model is a more accurate preclinical model than older generation serially passaged or genetic models to investigate current and newly developed androgen-deprivation agents, antitumour compounds, anti-angiogenic drugs and positron emission tomography radiotracers, as well as new therapeutic regimens for the treatment of PC.

Regulation of cell cycle and RNA transcription genes identified by microarray analysis of PC-3 human prostate cancer cells treated with luteolin

Prostate cancer is the second leading cause of cancer-related deaths in men in the United States. Our previous studies have shown that ligands for the nuclear type II [(3)H]estradiol binding site such as luteolin significantly inhibit prostate cancer cells in vitro and in vivo; however, the role of these ligands in cell growth and proliferation is poorly understood. In order to further elucidate the molecular mechanism through which luteolin exerts its effects on PC-3 cells, cRNA microarray analyses was performed on 38,500 genes to determine the genes altered by luteolin treatment. The expression of 3331 genes was changed greater than 1.2-fold after luteolin treatment. Analysis of the altered genes identified two pathways that were significantly affected by luteolin. The Cell Cycle Pathway contained 22 down-regulated genes (including polo-like kinase 1, cyclin A2, cyclin E2 and proliferation cell nuclear antigen) and one up-regulated gene (cyclin-dependent kinase inhibitor 1B). In addition, 13 genes were down-regulated by luteolin in the RNA Transcription Pathway. Real-time polymerase chain reactions and western blots verified the observations from the microarray. In addition, two synthetic, chemically distinct type II ligands, ZN-2 and BMHPC, mimicked the effects of luteolin on gene expression at the mRNA and protein level in PC-3 cells. Finally, chromatin immunoprecipitation assays indicated that luteolin exerts its effects on genes by altering the acetylation state of promoter-associated histones. Taken together, the data suggest that type II ligands inhibit cell growth and proliferation through epigenetic control of key genes involved in cell cycle progression and RNA transcription.

Changes in alkaline phosphatase levels in patients with prostate cancer receiving degarelix or leuprolide: results from a 12-month, comparative, phase III study

Study Type - Therapy (RCT) Level of Evidence 1b OBJECTIVE To compare the activity of degarelix, a new gonadotrophin-releasing hormone (GnRH) blocker, with leuprolide depot 7.5 mg in the control of total serum alkaline phosphatase (S-ALP) levels in patients with prostate cancer. PATIENTS AND METHODS In the randomized, phase III trial (CS21), patients with histologically confirmed prostate cancer (all stages), were randomized to one of three regimens: degarelix subcutaneous 240 mg for 1 month followed by monthly maintenance doses of 80 mg or 160 mg, or intramuscular leuprolide 7.5 mg/month. Patients receiving leuprolide could also receive antiandrogens for flare protection. We report exploratory S-ALP analyses from CS21, focusing on the comparison of degarelix 240/80 mg with leuprolide 7.5 mg, in line with the recent approvals of this dose by the USA Food and Drug Administration and the European Medicines Agency. RESULTS Overall, 610 patients were included, with a median age of 73 years and median prostate-specific antigen (PSA) level of 19.0 ng/mL. Baseline S-ALP levels were high in metastatic patients and highest in patients with metastatic disease and a haemoglobin level of <13 g/dL. In metastatic disease, after initial peaks in both groups, S-ALP levels were suppressed below baseline with degarelix but were maintained around baseline with leuprolide. The late rise in S-ALP seen with leuprolide was not apparent with degarelix. The pattern of S-ALP response was similar in patients with a baseline PSA level of > or =50 ng/mL. Between-treatment differences in patients with metastatic disease and those with a PSA level of > or =50 ng/mL were significant at day 364 (P = 0.014 and 0.007, respectively). CONCLUSION Patients with metastatic disease or those with PSA levels of > or =50 ng/mL at baseline had greater reductions in S-ALP levels with degarelix than with leuprolide. Patients in the degarelix group maintained S-ALP suppression throughout the study, in contrast to those in the leuprolide group. This suggests that degarelix might offer better S-ALP control than leuprolide and might prolong control of skeletal metastases, compared with GnRH agonists, over a 1-year treatment period.

Prostate cancer survivorship: prevention and treatment of the adverse effects of androgen deprivation therapy

BACKGROUND

More than one-third of the estimated 2 million prostate cancer survivors in the United States receive androgen deprivation therapy (ADT). This population of mostly older men is medically vulnerable to a variety of treatment-associated adverse effects.

MEASUREMENTS AND RESULTS

Androgen-deprivation therapy (ADT) causes loss of libido, vasomotor flushing, anemia, and fatigue. More recently, ADT has been shown to accelerate bone loss, increase fat mass, increase cholesterol and triglycerides, and decrease insulin sensitivity. Consistent with these adverse metabolic effects, ADT has also recently been associated with greater risks for fractures, diabetes and cardiovascular disease.

CONCLUSION

Primary care clinicians and patients should be aware of the potential benefits and harms of ADT. Screening and intervention to prevent treatment-related morbidity should be incorporated into the routine care of prostate cancer survivors. Evidence-based guidelines to prevent fractures, diabetes, and cardiovascular disease in prostate cancer survivors represent an important unmet need. We recommend the adapted use of established practice guidelines designed for the general population.

Early and delayed castrations confer a similar survival advantage in TRAMP mice

The most appropriate time to introduce androgen deprivation therapy for prostate cancer remains controversial. Our aim was to evaluate the effects of early versus delayed surgical castration on prostate cancer progression and survival in the transgenic adenocarcinoma of the mouse prostate (TRAMP) model. TRAMP mice were randomly divided into three groups: the early castration group (on which castration was performed at the age of 4 weeks), the delayed castration group (on which castration was performed when abdominal tumours could be palpated), and the sham-castrated group. Mice were monitored daily throughout their lives until cancer-related death or the development of an obviously moribund appearance, at which time the individual mouse was killed. Androgen receptor expression in prostate tumours was also evaluated. The results shows that the average lifespan in early castration, delayed castration and sham-castrated groups were 54.1 weeks, 59.9 weeks and 39.1 weeks, respectively. Both early castration and delayed castration conferred a statistically significant survival advantage when compared with the sham-castrated group (P<0.001). However, the difference in lifespan between the early castration group and the delayed castration group was not statistically significant (P=0.85). The increase in lifespan in the TRAMP mice that received either early or delayed castration correlated with lower G/B value (genitourinary tract weight/body weight) at death than the sham-castrated mice. In conclusion, early and delayed castrations in TRAMP mice prolonged survival to a similar extent. This finding may provide a guide for clinical practice in prostate cancer therapy.

[Androgen deprivation for advanced prostate cancer]

Androgen deprivation (ADT) by medical or surgical castration represents the standard therapeutic approach for managing prostate cancer (PCA) with systemic or locoregional metastases. Although ADT has been successfully used for more than 60 years, there are still major controversies with regard to the initiation (early versus delayed), type (complete versus monotherapy), and duration (continuous versus intermittent) of treatment. It is the purpose of this review to critically present the results of the various ADT options. Bilateral orchiectomy and subcutaneous application of luteinising hormone-releasing hormone (LHRH) analogues represent the guideline-recommended standard treatment for metastatic PCA, whereas estrogens are no longer recommended because of significant cardiovascular side effects despite comparable therapeutic efficacy. Antiandrogen monotherapy with bicalutamide is comparable to LHRH analogues in men with minimal tumour burden. However, survival rates are inferior in patients with extensive metastatic disease, in whom medical or surgical castration should be favoured. Complete ADT results in a median survival benefit of about 5% in men with low metastatic tumour burden, and it cannot be recommended for routine use. Early ADT is associated with a significant advantage in terms of symptom-free survival and prevention of metastasis-associated complications, but it does not result in a prolonged progression-free and overall survival when compared with delayed ADT. Despite encouraging results, intermittent ADT remains an experimental therapeutic approach that should be considered on an individual basis in carefully selected patients. Adjuvant ADT is still discussed controversially for men after radical prostatectomy, whereas it has become the standard approach in patients who undergo external beam radiation for locally advanced PCA.

Androgen deprivation falls as orchiectomy rates rise after changes in reimbursement in the U.S. Medicare population

BACKGROUND

Expenditures related to the use of medical androgen deprivation led in part to the Medicare Modernization Act (MMA) in 2003. This mandated a decline in reimbursement to 80% to 85% of the average wholesale price starting in 2004 followed by a more significant reduction in 2005 to 106% of the average sales price, which effectively reduced the reimbursement by approximately 50% of 2003 values. The authors hypothesized that these changes in reimbursement may affect the way practitioners administer these treatments.

METHODS

The publicly available dataset Medicare Part B Extract Summary System was examined from 2001 to 2005 for trends in the number of allowed services and dollar amounts of allowed charges and payments. The reimbursable Medicare codes of J9217 (leuprolide acetate), J9202 (goserelin acetate), J9219 (leuprolide acetate implant), and J3315 (triptorelin pamoate) were examined for medical castration. The code for simple orchiectomy, 54520, was used for surgical castration.

RESULTS

The use of medical castration increased from 2001 to 2003, whereas, over the same period, surgical castration decreased. Total allowed charges for medical castration peaked in 2003 at $1.23 billion. After the enactment of the MMA, surgical castration rates increased, and medical castration decreased. Total allowed charges for medical castration in 2005 dropped 65% from the 2003 peak.

CONCLUSIONS

The use of medical androgen ablation decreased significantly with the decrease in reimbursement. The administration of either surgical or medical castration in the U.S. Medicare population appears to be tied closely to reimbursement in trend, but not always in magnitude.