Role of secondary hormonal therapy in the management of recurrent prostate cancer

Apalutamide, Darolutamide and Enzalutamide for Nonmetastatic Castration-Resistant Prostate Cancer (nmCRPC): A Critical Review

Nonmetastatic castration-resistant prostate cancer (nmCRPC) represents a condition in which patients with prostate cancer show biochemical progression during treatment with androgen-deprivation therapy (ADT) without signs of radiographic progression according to conventional imaging. The SPARTAN, ARAMIS and PROSPER trials showed that apalutamide, darolutamide and enzalutamide, respectively, prolong metastasis-free survival (MFS) and overall survival (OS) of nmCRPC patients with a short PSA doubling time, and these antiandrogens have been recently introduced in clinical practice as a new standard of care. No direct comparison of these three agents has been conducted to support treatment choice. In addition, a significant proportion of nmCRPC on conventional imaging is classified as metastatic with new imaging modalities such as the prostate-specific membrane antigen positron emission tomography (PSMA-PET). Some experts posit that these "new metastatic" patients should be treated as mCRPC, resizing the impact of nmCRPC trials, whereas other authors suggest that they should be treated as nmCRPC patients, based on the design of pivotal trials. This review discusses the most convincing evidence regarding the use of novel antiandrogens in patients with nmCRPC and the implications of novel imaging techniques for treatment selection.

Resistance to Androgen Deprivation Leads to Altered Metabolism in Human and Murine Prostate Cancer Cell and Tumor Models

Currently, no clinical methods reliably predict the development of castration-resistant prostate cancer (CRPC) that occurs almost universally in men undergoing androgen deprivation therapy. Hyperpolarized (HP) ¹³C magnetic resonance imaging (MRI) could potentially detect the incipient emergence of CRPC based on early metabolic changes. To characterize metabolic shifts occurring upon the transition from androgen-dependent to castration-resistant prostate cancer (PCa), the metabolism of [U-¹³C]glucose and [U-¹³C]glutamine was analyzed by nuclear magnetic resonance spectroscopy. Comparison of steady-state metabolite concentrations and fractional enrichment in androgen-dependent LNCaP cells and transgenic adenocarcinoma of the murine prostate (TRAMP) murine tumors versus castration-resistant PC-3 cells and treatment-driven CRPC TRAMP tumors demonstrated that CRPC was associated with upregulation of glycolysis, tricarboxylic acid metabolism of pyruvate; and glutamine, glutaminolysis, and glutathione synthesis. These findings were supported by ¹³C isotopomer modeling showing increased flux through pyruvate dehydrogenase (PDH) and anaplerosis; enzymatic assays showing increased lactate dehydrogenase, PDH and glutaminase activity; and oxygen consumption measurements demonstrating increased dependence on anaplerotic fuel sources for mitochondrial respiration in CRPC. Consistent with ex vivo metabolomic studies, HP [1-¹³C]pyruvate distinguished androgen-dependent PCa from CRPC in cell and tumor models based on significantly increased HP [1-¹³C]lactate.

Association Between CYP17A1, CYB5A Polymorphisms and Efficacy of Abiraterone Acetate/Prednisone Treatment in Castration-Resistant Prostate Cancer Patients

PURPOSE

The purpose of this study was to investigate the association between single nucleotide polymorphisms (SNPs) of CYP17A1, CYB5A and the efficacy of abiraterone acetate treatment in patients with castration-resistant prostate cancer (CRPC).

PATIENTS AND METHODS

Data were collected from 58 CRPC patients who had been treated with abiraterone acetate/prednisone (AA/P). The SNPs rs743572 and rs10883783 on CYP17A1 and SNPs rs1790834 and rs1790858 on CYB5A were assayed, and their relationship with prostate-specific antigen (PSA) response in patients after AA/P treatment, overall survival (OS) and progression-free survival (PFS) were analyzed by logistic regression, Cox regression, Kaplan-Meier and Log rank analyses.

RESULTS

The SNP rs1790834 on CYB5A showed significant association with PSA response in CRPC patients treated with AA/P (P < 0.05), but rs743572, rs10883783 and rs1790858 did not. The rs1790834 variant significantly decreased both PFS and OS (P < 0.05).

CONCLUSION

The CYB5A rs790834 genotype is a novel SNP related to CRPC and may be used as a biomarker for CRPC treatment.

Saudi oncology society and Saudi urology association combined clinical management guidelines for prostate cancer

This is an update to the previously published Saudi guidelines for the evaluation, medical, and surgical management of patients diagnosed with prostate cancer. It is categorized according to the stage of the disease using the tumor node metastasis staging system 7(th) edition. The guidelines are presented with supporting evidence level, they are based on comprehensive literature review, several internationally recognized guidelines, and the collective expertise of the guidelines committee members (authors) who were selected by the Saudi oncology society and Saudi urological association. Considerations to the local availability of drugs, technology, and expertise have been regarded. These guidelines should serve as a roadmap for the urologists, oncologists, general physicians, support groups, and health care policy makers in the management of patients diagnosed with adenocarcinoma of the prostate to.

Efficacy and toxicity of anti-VEGF agents in patients with castration-resistant prostate cancer: a meta-analysis of prospective clinical studies

BACKGROUND

Blocking angiogenesis by targeting vascular endothelial growth factor (VEGF) signaling pathway to inhibit tumor growth has proven to be successful in treating a variety of different metastatic tumor types, including kidney, colon, ovarian, and lung cancers, but its role in castration-resistant prostate cancer (CRPC) is still unknown. We here aimed to determine the efficacy and toxicities of anti-VEGF agents in patients with CRPC.

MATERIALS AND METHODS

The databases of PubMed, Web of Science and abstracts presented at the American Society of Clinical Oncology up to March 31, 2014 were searched for relevant articles. Pooled estimates of the objective response rate (ORR) and prostate-specific antigen (PSA) response rate (decline ≥50%) were calculated using the Comprehensive Meta-Analysis (version 2.2.064) software. Median weighted progression- free survival (PFS) and overall survival (OS) time for anti-VEGF monotherapy and anti-VEGF-based doublets were compared by two-sided Student's t test.

RESULTS

A total of 3,841 patients from 19 prospective studies (4 randomized controlled trials and 15 prospective nonrandomized cohort studies) were included for analysis. The pooled ORR was 12.4% with a higher response rate of 26.4% (95%CI, 13.6-44.9%) for anti-VEGF-based combinations vs. 6.7% (95%CI, 3.5-12.7%) for anti-VEGF alone (p=0.004). Similarly, the pooled PSA response rate was 32.4% with a higher PSA response rate of 52.8% (95%CI: 40.2-65.1%) for anti-VEGF-based combinations vs. 7.3% (95%CI, 3.6-14.2%) for anti-VEGF alone (p<0.001). Median PFS and OS were 6.9 and 22.1 months with weighted median PFS of 5.6 vs. 6.9 months (p<0.001) and weighted median OS of 13.1 vs. 22.1 months (p<0.001) for anti-VEGF monotherapy vs. anti-VEGF-based doublets.

CONCLUSIONS

With available evidence, this pooled analysis indicates that anti-VEGF monotherapy has a modest effect in patients with CRPC, and clinical benefits gained from anti-VEGF-based doublets appear greater than anti-VEGF monotherapy.

Bicalutamide 150 mg as secondary hormonal therapy for castration-resistant prostate cancer

PURPOSE

This study was aimed to evaluate the effect and tolerability of bicalutamide 150 mg therapy in patients with castration-resistant prostate cancer (CRPC).

METHODS

A total of 48 patients with histologically confirmed prostate cancer were included. They had been treated with continuous maximal androgen blockade therapy, but their serum prostate-specific antigen (PSA) increased after initial hormonal therapy. Patients were given bicalutamide (150 mg per day). Serum PSA testing was performed every 3 months. The response was defined according to PSA decline from baseline: PSA decline ≥85% as complete response, ≥50 % but <85% as partial response, and <50 % as failure. Response duration was defined as the time from PSA response until PSA increased ≥25 % or ≥2 ng/mL from the nadir. The potential predictive factors (Gleason score, clinical stage and serum PSA) were investigated.

RESULTS

The time of follow-up was 3-30 months. A PSA decline ≥50% was observed in 37 of 48 patients including 18 ≥ 50% but <85% and 19 ≥ 85% responders. The median response duration was 12 months for partial responders and 20 months for complete responders. Patients with lower Gleason score, lower serum PSA and using flutamide as first-line nonsteroidal antiandrogen achieved more benefits. Moreover, bicalutamide 150 mg therapy was well tolerated.

CONCLUSIONS

Bicalutamide 150 mg therapy was an appropriate therapeutic method for patients of CRPC, especially for those with lower Gleason score, lower serum PSA and using flutamide as first-line nonsteroidal antiandrogen.

Limited in vitro efficacy of CYP17A1 inhibition on human castration resistant prostate cancer

Although accumulating evidence indicates high expression of CYP17A1(P45017A1) allows castration resistant prostate cancer (CRPC) to maintain high intratumoral androgen levels, the potential P45017A1 activity has not been characterized yet. The aim of this study was to examine the potential CYP17A1 activity including 17α-hydroxylase and 17,20-lyase activities in human CRPC and the effect of a CYP17A inhibitor. We used three human CRPC cell lines: C4-2 and C4-2AT6 which was established from C4-2 under androgen ablation conditions for 6months, and PC3. To ascertain the potential CYP17A1 activity, we cultured with the steroid precursors: (13)C-[2,3,4]-progesterone (13C-Prog), and analyzed the sequential biosynthesis (13)C-[2,3,4]-17-hydroxyprogesterone (13C-17OHP) and (13)C-[2,3,4]-androstenedione(13C-Adione) by liquid chromatography/mass spectrometry (LC/MS/MS).The C4-2AT6 cells showed significantly higher CYP17A1 expression than C4-2 cells (p<0.001). LC/MS/MS analysis enabled us to detect the 13C-17-OHP and 13C-A-dione in these cell lines. The concentration ratio of 13C-Adione/13C-17OHP (Adione-17OHP ratio), which is thought to reflect the differences between 17-hydroxylase and 17,20-lyase activities, was then determined. The Adione-17OHP ratio in C4-2AT6 cells was significantly higher than that of C4-2 cells (p<0.001). Abiraterone were able to inhibit the CYP17A activities, although abiraterone did not have anti-proliferative effects on C4-2 and C4-2AT6 cells at clinically achievable concentrations of <1000nM in vitro. The present study clearly demonstrates CRPC have the dual activities of CYP17A1 mediated by 17-hydroxylase activity and 17,20-lyase activity. Abiraterone doesn't have an in vitro anti-proliferative efficacy in CRPC cells, suggesting limited efficacy in vitro.

Saudi oncology society and Saudi urology association combined clinical management guidelines for prostate cancer

In this report, updated guidelines for the evaluation, medical, and surgical management of prostate cancer are presented. They are categorized according the stage of the disease using the tumor node metastasis staging system 7(th) edition. The recommendations are presented with supporting evidence level.

Human castration resistant prostate cancer rather prefer to decreased 5α-reductase activity

Physiologically relevant steroid 5α-reductase (SRD5A) activity that is essential for dihydrotestosterone (DHT) biosynthesis in human castration-resistant prostate cancer (CRPC) has not been fully characterized yet. In this study to ascertain the potential SRD5A activity, we cultured two human CRPC cell lines, C4-2 and C4-2AT6, with the steroid precursor: ¹³C-[2,3,4]-androstenedione (13C-Adione), and analyzed the sequential biosynthesis of ¹³C-[2,3,4]-testosterone (13C-T) and ¹³C-[2,3,4]-DHT (13C-DHT) by liquid chromatography/mass spectrometry (LC/MS/MS). The 13C-DHT/13C-T concentration ratio detected by LC/MS/MS in C4-2AT6 cells appeared to reflect the SRD5A activity. The ratio in C4-2AT6 was significantly lower than that in C4-2. An increased concentration of DHT did not have a positive effect on cell proliferation, rather it exhibited inhibitory effects. 5α-reductase inhibitors did not have any inhibitory effect at clinically achievable concentrations. These results indicate that CRPC cells may have an unknown regulation system to protect themselves from an androgenic suppressive effect mediated by SRD5A activity.

Chemotherapy-based treatment for castration-resistant prostate cancer

Most men with metastatic prostate cancer respond to various types of androgen ablation but progress to castration-resistant disease. The TAX 327 and Southwest Oncology Group (SWOG) 99-16 clinical trials established docetaxel-based chemotherapy as preferred first-line treatment for most men with symptomatic metastatic castration-resistant prostate cancer (mCRPC). However, only about half receive benefit from docetaxel, and those who respond initially progress and eventually die of (or with) mCRPC. Both cellular mechanisms and the tumor microenvironment are implicated in the development of resistance to docetaxel. New agents are being evaluated for men with mCRPC, either as first-line treatment in combination with docetaxel, or in men progressing during or after treatment with docetaxel. Thus far, agents evaluated in phase III trials in combination with docetaxel have not improved outcome, including the vaccine GVAX, high-dose vitamin D (DN-101), and the antiangiogenic agent bevacizumab. In contrast, cabazitaxel, a taxane that is not cross-resistant to docetaxel, substantially improved the outcome of men progressing during or after treatment with docetaxel-based chemotherapy when compared with mitoxantrone and prednisone. However, translation of benefit of cabazitaxel demonstrated in the TROPIC (Treatment of Hormone-Refractory Metastatic Prostate Cancer) trial into general oncologic practice will be challenging because this agent may cause serious toxicity. With the approval of less toxic hormonal agents (eg, abiraterone acetate) in the setting of docetaxel-resistant mCRPC, clinicians will have an opportunity to balance benefits and harms of new agents in an individual patient and may be able to use different agents in sequence.

Saudi Oncology Society clinical management guidelines for prostate cancer

In this report, guidelines for the evaluation, medical and surgical management of testicular germ cell tumors is presented. It is categorized according to the stage of the disease using the tumor node metastasis staging system, 7th edition. The recommendations are presented with supporting level of evidence.

Comparison of Ketoconazole and Estramustine for Treating Patients with Castration-Resistant Prostate Cancer

Purpose

We investigated the efficacy of ketoconazole and estramustine before chemotherapy for treating patients with progressive castration-resistant prostate cancer (CRPC) after anti-androgen withdrawal syndrome.

Materials and Methods

Eighty-four patients who were diagnosed with CRPC and were treated between 2005 and 2009 were included. Thirty-nine patients were treated with 600 mg of ketoconazole and 10 mg of prednisolone per day (group I), and 45 patients were treated with 560 mg of estramustine per day (group II). The prostate-specific antigen (PSA) response, progression-free survival, and side effects were compared.

Results

The median age of the patients, PSA level, and follow-up period were 72 years, 48.5 ng/ml, and 4 months (range, 1 to 29 months), respectively. The overall PSA response rate was 35.7%, and the PSA response rates were 33.3% for group I and 37.8% for group II (p=0.672). The median progression-free survival times were 8 months (95% confidence interval [CI] 5.9-10.1) overall, 5 months (95% CI 1.6-8.3) in group I, and 8 months (95% CI 5.9-10.0) in group II (p=0.282). The most common complications in groups I and II were nausea and vomiting (51.3%) and anemia (77.8%), respectively. Nausea and vomiting and hepatotoxicity were observed more often in group I, and gynecomastia, neutropenia, and anemia were observed more often in group II. The toxicities of each adverse effect were ≤grade 2.

Conclusions

With a resultant PSA decline and mild adverse effects, both ketoconazole and estramustine are worth consideration as treatment options for progressive CRPC patients after primary hormonal therapy.

Innovations in the systemic therapy of prostate cancer

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

[EAU guidelines on prostate cancer]

OBJECTIVES

To present a summary of the 2007 version of the European Association of Urology (EAU) guidelines on prostate cancer (PCa).

METHODS

A literature review of the new data emerging from 2004 to 2007 was performed by the working panel. The guidelines have been updated, and the level of evidence/grade of recommendation was added to the text based on a systematic review of the literature, which included a search of online databases and bibliographic reviews.

RESULTS

A full version is available at the EAU Office or at www.uroweb.org. Systemic prostate biopsy under ultrasound guidance is the preferred diagnostic method. Active treatment is mostly recommended for patients with localized disease and a long life expectancy, with radical prostatectomy being shown to be superior to watchful waiting in a prospective randomized trial. Nerve-sparing radical prostatectomy represents the approach of choice in organ-confined disease; neoadjuvant androgen deprivation demonstrates no improvement of outcome variables. Radiation therapy should be performed with at least 72 and 78 Gy in low-risk and intermediate- to high-risk PCa, respectively. Monotherapeutic androgen deprivation is the standard of care in metastatic PCa; intermittent androgen deprivation might be an alternative treatment option for selected patients. Follow-up is largely based on prostate-specific antigen and a disease-specific history with imaging only indicated when symptoms occur. Cytotoxic therapy with docetaxel has emerged as the reference treatment for metastatic hormone-refractory PCa.

CONCLUSIONS

The knowledge in the field of PCa is rapidly changing. These EAU guidelines on PCa summarize the most recent findings and put them into clinical practice.

[Prostate cancer: evidence based clinical practice]

OBJECTIVES

Evidence-based medicine allows the best available external clinical evidence from systematic literature research to be graded in order to determine the strength of its recommendation. This guideline aims to assist physicians and health professionals in clinical decisions related to prostate cancer treatment, particularly in urology, clinical oncology and radiotherapy.

METHODS

The publications used as information sources were obtained from structured data search in electronic databases, such as CENTRAL (Cochrane Central Register of Controlled Clinical Trials) and MEDLINE (online). Each item of this guideline derived from an original question which was distributed to the participants. Search strategies were prepared to select the studies presenting the best methodological quality, according to predefined levels of evidence.

RESULTS

All the recommendations were followed by a level of evidence (LE) and a degree of recommendation (DR). We used a formal ranking system to help the reader to judge the strength of the evidence behind the results published in support of each recommendation.

CONCLUSIONS

The existing parameters should be viewed as guidelines of conduct. The final trial on which the clinical procedure or treatment plan is most suitable for a particular patient should be done by a physician, who should discuss the available treatment options with the patient according to the diagnosis.

Enhanced Interaction between Warfarin and High-Dose Ketoconazole: A Case Report

This case describes the increased anticoagulation effect associated with the use of high-dose ketoconazole. A 59-year-old man treated with warfarin for aortic valve replacement was prescribed high-dose ketoconazole and hydrocortisone for the treatment of prostate cancer. Despite lowering the warfarin dosage by 35% during the start of high dose ketoconazole, an additional dose reduction was required subsequently when the INR rose from 2.62 to 3.82 within nine days. After a total dose reduction of 43%, the INR returned to therapeutic range within two weeks. The Naranjo probability scale revealed a probable adverse reaction of increased anticoagulant effect associated with high dose ketoconazole. Due to the inhibition of warfarin metabolism by ketoconazole, patients taking high dose ketoconazole concomitantly with warfarin may need their warfarin dosage reduced by more than is currently recommended, as well as receive more frequent INR monitoring to avoid over anticoagulation.

Efficacy of Low-dose Ketoconazole in Hormone Refractory Prostate Cancer Patients at the National Cancer Centre and The Cancer Institute, Singapore

Introduction: The advent of prostate specific antigen (PSA) has resulted in an increased incidence of early detection of prostate cancer recurrence. Patients treated with androgen deprivation therapy (ADT) become hormone-resistant after 18 to 24 months. In patients with biochemical failure, where there is a rise in PSA but no objective evidence of metastases, or in whom there are small volume metastases but who are asymptomatic, there is no standard of care after ADT. Ketoconazole, an antimycotic which affects the synthesis of androgens and other steroids, has shown direct cytotoxic effects in prostate cancer cell lines in in-vitro studies. This study describes our experience with ketoconazole treatment for hormone refractory prostate cancer (HRPC). Materials and Methods: A retrospective study of HRPC patients given ketoconazole at the National Cancer Centre and The Cancer Institute from 2004 to 2005 was performed. All eligible patients had histologically proven adenocarcinoma of the prostate and a rising PSA level despite ADT with orchidectomy or luteinising hormone-releasing hormone (LHRH) agonist therapy. All patients received 200 mg of ketoconazole thrice daily. Response was defined as a decline in PSA of at least 50% from the pre-treatment level and confirmed by a second PSA value 4 or more weeks later. The endpoints evaluated were the presence and duration of a response and the toxicity profile of the treatment. Results: A total of 32 patients with HRPC were treated with ketoconazole. Twelve (38%) of the 32 patients had a greater than 50% decrease in their PSA values. The median duration of response was 6.75 months. The median time to reach PSA nadir was 3.5 months. Five patients continue to exhibit progression-free response at the time of writing. Ketoconazole was generally well tolerated. Eighteen (56%) patients recorded mild toxicities related to ketoconazole. There were no grade 3 or 4 toxicities. Key words: Androgen deprivation therapy, Prostate specific antigen

EAU guidelines on prostate cancer

OBJECTIVES

To present a summary of the 2007 version of the European Association of Urology (EAU) guidelines on prostate cancer (PCa).

METHODS

A literature review of the new data emerging from 2004 to 2007 was performed by the working panel. The guidelines have been updated, and the level of evidence/grade of recommendation was added to the text based on a systematic review of the literature, which included a search of online databases and bibliographic reviews.

RESULTS

A full version is available at the EAU Office or at www.uroweb.org. Systemic prostate biopsy under ultrasound guidance is the preferred diagnostic method. Active treatment is mostly recommended for patients with localized disease and a long life expectancy, with radical prostatectomy being shown to be superior to watchful waiting in a prospective randomized trial. Nerve-sparing radical prostatectomy represents the approach of choice in organ-confined disease; neoadjuvant androgen deprivation demonstrates no improvement of outcome variables. Radiation therapy should be performed with at least 72 and 78 Gy in low-risk and intermediate- to high-risk PCa, respectively. Monotherapeutic androgen deprivation is the standard of care in metastatic PCa; intermittent androgen deprivation might be an alternative treatment option for selected patients. Follow-up is largely based on prostate-specific antigen and a disease-specific history with imaging only indicated when symptoms occur. Cytotoxic therapy with docetaxel has emerged as the reference treatment for metastatic hormone-refractory PCa.

CONCLUSIONS

The knowledge in the field of PCa is rapidly changing. These EAU guidelines on PCa summarize the most recent findings and put them into clinical practice.

Prostate cancer: a practical approach to current management of recurrent disease

Prostate cancer is the leading cause of cancer in men in the United States, with 234,460 men expected to be diagnosed as having the disease in 2006 (33% of cancers in men), and the third leading cause of cancer deaths in men, with 27,350 men expected to die of the disease (9% of cancer deaths). Through early detection and improved local therapies, including surgery or radiation therapy, a large number of men will be cured, but unfortunately, a significant number of men will still experience relapse of disease and require continued surveillance and ongoing therapy. This article discusses approaches to treatment of men who have recurrent disease, including active surveillance, androgen ablation therapy, secondary hormone therapy, chemotherapy, bisphosphonates, radiation therapy, and future directions.

Obesity and sex steroids during gonadotropin-releasing hormone agonist treatment for prostate cancer

PURPOSE

To evaluate effects of obesity on sex steroid levels during treatment with a gonadotropin-releasing hormone agonist in men with prostate cancer.

EXPERIMENTAL DESIGN

Forty-nine hormone-naïve men with recurrent or locally advanced prostate cancer were included in the analyses. All subjects were treated with leuprolide 3-month depot for 48 weeks. Serum levels of estradiol, sex hormone-binding globulin, total testosterone, and free testosterone were assessed at baseline, 24 weeks, and 48 weeks. Subjects were categorized by body mass index (BMI) and percent body fat.

RESULTS

Pretreatment serum sex hormone-binding globulin and total testosterone levels were significantly lower in overweight and obese men than in men with normal BMI. In the overall study population, mean serum testosterone concentrations decreased from 372 +/- 18 ng/dL at baseline to 13 +/- 1 ng/dL at week 48 (P < 0.001). Free testosterone decreased from 6.75 +/- 0.33 ng/dL at baseline to 0.21 +/- 0.02 ng/dL at week 48 (P < 0.001). During treatment with leuprolide, obese men had significantly higher total and free testosterone levels than men with normal BMI. Compared with normal men, total and free testosterone levels during treatment were 1.8-fold and 2.3-fold higher in obese men. Similar results were observed when subjects were categorized by body fat.

CONCLUSIONS

Despite lower pretreatment serum testosterone levels, obese men have higher total and free testosterone levels during leuprolide treatment than men with normal BMI. These differences may contribute to the association between obesity and increased prostate cancer mortality.

Guidelines and counselling for treatment options in the management of prostate cancer

Prostate cancer is often a complex disease and one in which many aspects of the disease and the affected patient must be taken into consideration before decisions about diagnostic work-up, treatments, follow-up, etc. can be made. The current chapter reflects the current recommendations of the European Prostate Cancer Guideline Group made on the basis of criteria of evidence-based medicine after extensive review of the literature available up to December 2005.

Platinum(II) complexes interfering with testicular steroid biosynthesis: drugs for the therapy of advanced or recurrent prostate cancers? Preclinical studies

[Meso-1,2-bis(2,6-dihalo-3/4-hydroxyphenyl)ethylenediamine]platinum(II) complexes (meso-1-PtLL': 2,6-F(2),3-OH; meso-2-PtLL': 2,6-F(2),4-OH; meso-3-PtLL': 2,6-Cl(2),3-OH; meso-4-PtLL': 2,6-Cl(2),4-OH; L = OH(2), L' = OSO(3) or L,L' = Cl(2)) were designed with the aim to get drugs comprising both cytotoxic and testosterone level lowering potencies. It is assumed that such compounds are more efficient than the established endocrine therapeutic measures and can affect the development of hormone refractory prostate cancer (PC). With exception of meso-3-PtLL' all Pt-complexes and the comparison compound cisplatin significantly reduced the testosterone level in experiments on male rats. However, in the test on the Dunning R3327 PC of the rat only cisplatin and meso-4-PtLL' showed a significant anti-tumor activity at well-tolerated dose ranges. Meso-4-PtLL' also significantly extended the time to disease progression in comparison with orchiectomy in this tumor model. Interestingly, the relapsed tumor, too, responded to meso-4-PtLL' as demonstrated in a long-term study on orchiectomized rats bearing Dunning R3327 PC grafts. This effect cannot be ascribed to cytotoxic effects of meso-4-PtLL' because of its inactivity on the human LNCaP/FGC PC cell line. Therefore, the contribution of an additional mechanism to the anti-prostate cancer activity of meso-4-PtLL', presumably owing to its estrogenic potency, must be considered. This assumption was supported by test results with diethylstilbestrol (DES) (non-steroidal estrogen) on the Dunning R3327 PC of the rat relapsed after orchiectomy. This tumor model was strongly inhibited by DES. The possible mode of action of meso-4-PtLL' is thoroughly discussed.

Deferred combined androgen blockade therapy using bicalutamide in patients with hormone-refractory prostate cancer during androgen deprivation monotherapy

OBJECTIVE

To assess the effect of adding bicalutamide on serum prostate-specific antigen (PSA) levels in patients with hormone-refractory prostate cancer (HRPC) during androgen deprivation monotherapy (ADMT).

PATIENTS AND METHODS

Forty-four patients with HRPC were treated with deferred combined androgen blockade (CAB) therapy, administering bicalutamide 80 mg once daily. HRPC was defined biochemically as three consecutive rises in PSA level during ADMT. The treatment response was defined as a > or = 50% decline in PSA levels. Prognostic values of various pretreatment variables for responsiveness to deferred CAB were determined statistically. When the disease relapsed during deferred CAB, bicalutamide was discontinued and the patients were evaluated for the antiandrogen withdrawal syndrome (AWS).

RESULTS

Of the 44 patients, 29 (66%) had a PSA response; the median PSA failure-free survival was 9.2+ months. Biopsy Gleason score was the only pretreatment variable predictive of a PSA response (mean Gleason score 7.9 in responders and 8.7 in nonresponders). The PSA doubling time (PSA-DT) was the only statistically significant variable of PSA failure-free survival in a multivariate analysis. The 1- and 2-year PSA failure-free survival rates were 43% and 31% in patients with a PSA-DT of >4 months, while it was 21% and none, respectively, in those with a PSA-DT of <4 months. Responders to deferred CAB had a statistically longer cancer-specific survival than nonresponders. None of 20 patients who were evaluated for AWS had the condition.

CONCLUSIONS

Deferred CAB therapy using bicalutamide is effective in patients with progression during ADMT, particularly in those with lower Gleason score tumours or a longer PSA-DT. AWS after deferred CAB is uncommon.

Therapieoptionen beim hormonrefraktären Prostatakarzinom

For a long time, hormone-refractory prostate cancer was regarded as a chemoresistant tumor. The introduction of taxanes has prompted a change in this opinion. For the first time treatment with 75 mg/m(2) docetaxel every 3 weeks has evidenced a survival benefit in a phase III trial (median survival of 18.9 months versus 16.5 months with mitoxantrone). Further advantages were improved pain reduction and quality of life. Neutropenia was foremost among the side effects. Docetaxel is currently the standard treatment for hormone-refractory prostate cancer. The morbidity of metastatic hormone-refractory prostate cancer is influenced by bone metastases. Pain is a prominent feature. Skeletal complications are frequent. Therapy with 4 mg zoledronic acid reduced skeletal complications significantly in comparison to placebo. The most pronounced effect is the reduction of pathological fractures. Side effects include flu-like symptoms, muscle pain, and edemas. Zoledronic acid also belongs to the standard treatment of hormone-refractory prostate cancer with bone metastases.

Evaluation of hydrogen ion concentrations in prostates from rats and dogs using fluorescent confocal microscopy

The knowledge of intracellular spatial distribution of pH in prostates in animal models reflective of human prostate may have implications for drug development upon pH dependent drug delivery and activity. Freshly dissected prostate tissues (in vitro) or the entire prostate gland (in vivo) were loaded with fluorescent dyes and viewed using confocal microscopy. Images were initially taken in tissues perfused with RPMI-1640 medium. Calibration in situ was performed with high potassium buffers of known pH containing nigericin. Acetoxymethyl ester carboxy-SNARF-1 was visible in epithelial cells (but not stroma) in rat and dog prostates. The pH of lysosomes in prostate epithelial cells was 5.2 as determined by fluorescence of Lyso Sensor Green DND-189. A method of in situ confirmation of tissue viability was developed by a secondary loading and visualization of the BCECF fluorescent dye. Besides the direct measurement of the pH in rat and dog tissues (pH approximately 7.0), a method of pH measurement in prostate tissue (rather than in cell culture) was developed.

Second-Line Chemotherapy for Hormone-Refractory Prostate Cancer: Has the Time Come?

Prostate-specific antigen testing has not only led to an earlier diagnosis of prostate cancer, but also to an earlier identification of hormone-refractory prostate cancer (HRPC). Many patients identified early with HRPC may receive first-line taxane-based chemotherapy. Patients who progress after first-line chemotherapy are still quite healthy and desire further therapy. No proven treatment options exist for the second-line treatment of HRPC. Finding new agents that are active in the second-line setting and identifying relevant outcome variables and predictive pretreatment variables are crucial in improving survival and quality of life for this patient population.