Phase II study of single-agent orteronel (TAK-700) in patients with nonmetastatic castration-resistant prostate cancer and rising prostate-specific antigen

Orteronel for Metastatic Hormone-Sensitive Prostate Cancer: A Multicenter, Randomized, Open-Label Phase III Trial (SWOG-1216)

PURPOSE

Orteronel (TAK-700) is a nonsteroidal 17,20-lyase inhibitor suppressing androgen synthesis. We evaluated the clinical benefit of orteronel when added to androgen deprivation therapy (ADT) in patients with newly diagnosed metastatic hormone-sensitive prostate cancer.

METHODS

In this open-label randomized phase III study, patients with metastatic hormone-sensitive prostate cancer were randomly assigned 1:1 to ADT with orteronel (300 mg oral twice daily; experimental arm) or ADT with bicalutamide (50 mg oral once daily; control arm). The primary objective was the comparison of overall survival (OS), targeting a 33% improvement in median survival. A stratified log-rank test with a one-sided P ≤ .022 would indicate statistical significance. Secondary end points were progression-free survival (PFS), prostate-specific antigen (PSA) level at 7 months (≤ 0.2 v 0.2 to ≤ 4 v > 4 ng/mL), and adverse event profile.

RESULTS

Among 1,279 patients included in the analysis, 638 were randomly assigned to the ADT plus orteronel arm and 641 to the control arm. The median age was 68 years; 49% had extensive disease. After a median follow-up of 4.9 years, there was a significant improvement in PFS (median 47.6 v 23.0 months, hazard ratio 0.58; 95% CI, 0.51 to 0.67; P < .0001) and PSA response at 7 months (P < .0001), but not in OS (median 81.1 v 70.2 months, hazard ratio 0.86; 95% CI, 0.72 to 1.02; P = .040, one-sided). More grade 3/4 adverse events occurred in the experimental versus the control arms (43% v 14%). Postprotocol life-prolonging therapy was received by 77.4% of patients in the control arm and 61.3% of patients in the orteronel arm.

CONCLUSION

The study did not meet the primary end point of improved OS with orteronel. The lack of correlation of PFS and PSA response with OS raises concerns over assumption of their consistent surrogacy for OS in the context of extensive postprotocol therapy in this setting.

Novel Target Opportunities in Non-Metastatic Castrate Resistant Prostate Cancer

Nearly one third of men will incur biochemical recurrence after treatment for localized prostate cancer. Androgen deprivation therapy (ADT) is the therapeutic mainstay; however, some patients will transition to a castrate resistant state (castrate resistant prostate cancer, CRPC). Subjects with CRPC may develop symptomatic metastatic disease (mCRPC) and incur mortality several years later. Prior to metastatic disease, however, men acquire non-metastatic CRPC (nmCRPC) which lends the unique opportunity for intervention to delay disease progression and symptoms. This review addresses current therapies for nmCRPC, as well as novel therapeutics and pathway strategies targeting men with nmCRPC.

Non-metastatic castration-resistant prostate cancer: current status and future directions

INTRODUCTION

The emergence of novel hormonal therapies and the increase availability of sensitive next-generation imaging techniques has significantly changed the management of recurrent prostate cancer.

AREAS COVERED

In this review, we summarize the definition, diagnosis, treatment, and ongoing clinical trials in non-metastatic castration resistant prostate cancer (M0CRPC). We have also discussed the role of newer imaging modalities in the detection of advanced prostate cancer.

EXPERT OPINION

M0CRPC is a disease state in prostate cancer when serologic progression (PSA only disease) occurs despite castrated levels of testosterone and imaging shows no evidence of metastasis. With the availability of next-generation imaging, more patients are migrating from M0CRPC to mCRPC space. This stage migration impacts the treatment options currently available in clinical practice and requires the integration of novel imaging in prospective studies moving forward. Until that data become available men with M0CRPC should be considered for therapy with any of these three novel oral AR inhibitors, with a positive impact in metastasis-free and overall survival. Treatment selection should be based on Quality of Life, side effects, and drug-drug interactions.

Prostate Cancer Disparity, Chemoprevention, and Treatment by Specific Medicinal Plants

Prostate cancer (PC) is one of the most common cancers in men. The global burden of this disease is rising. Its incidence and mortality rates are higher in African American (AA) men compared to white men and other ethnic groups. The treatment decisions for PC are based exclusively on histological architecture, prostate-specific antigen (PSA) levels, and local disease state. Despite advances in screening for and early detection of PC, a large percentage of men continue to be diagnosed with metastatic disease including about 20% of men affected with a high mortality rate within the African American population. As such, this population group may benefit from edible natural products that are safe with a low cost. Hence, the central goal of this article is to highlight PC disparity associated with nutritional factors and highlight chemo-preventive agents from medicinal plants that are more likely to reduce PC. To reach this central goal, we searched the PubMed Central database and the Google Scholar website for relevant papers. Our search results revealed that there are significant improvements in PC statistics among white men and other ethnic groups. However, its mortality rate remains significantly high among AA men. In addition, there are limited studies that have addressed the benefits of medicinal plants as chemo-preventive agents for PC treatment, especially among AA men. This review paper addresses this knowledge gap by discussing PC disparity associated with nutritional factors and highlighting the biomedical significance of three medicinal plants (curcumin, garlic, and Vernonia amygdalina) that show a great potential to prevent/treat PC, as well as to reduce its incidence/prevalence and mortality, improve survival rate, and reduce PC-related health disparity.

Managing Nonmetastatic Castration-resistant Prostate Cancer

CONTEXT

Patients with nonmetastatic castration-resistant prostate cancer (nmCRPC) have rising prostate-specific antigen (PSA) and castrate testosterone levels, with no radiological findings of metastatic disease on computed tomography and bone scan. Given recent drug approvals for nmCRPC, with many other therapeutics and imaging modalities being developed, management of nmCRPC is a rapidly evolving field that merits detailed investigation.

OBJECTIVE

To review current nmCRPC management practices and identify opportunities for improving care of nmCRPC patients.

EVIDENCE ACQUISITION

A literature search up to July 2018 was conducted, including clinical trials and clinical practice guidelines (National Comprehensive Cancer Network, European Society for Medical Oncology, European Association of Urology, Prostate Cancer Clinical Trials Working Group, Prostate Cancer Radiographic Assessments for Detection of Advanced Recurrence). Keywords included prostate cancer, nonmetastatic, castration resistance, rising PSA, and biochemical relapse.

EVIDENCE SYNTHESIS

Recommendations regarding indications for, and frequency of, imaging and PSA testing, as well as for initiating systemic therapy in nmCRPC are based on PSA rise kinetics and symptoms. Both enzalutamide and apalutamide have been shown to significantly increase metastasis-free survival in phase III placebo-controlled randomised trials in nmCRPC patients with PSA doubling time (DT) ≤10 mo. The expected impact of new imaging techniques in the assessment of nmCRPC is also reviewed.

CONCLUSIONS

nmCRPC is a heterogeneous disease; while observation may be an option for some patients, enzalutamide and apalutamide may be appropriate to treat nmCRPC patients with PSA-DT ≤10 mo. The emergence of more accurate imaging modalities as well as circulating tumour biomarker assays will likely redefine the assessment of nmCRPC in the near future.

PATIENT SUMMARY

Herein, we review key literature and clinical practice guidelines to summarise the optimal management of patients with prostate cancer and rising prostate-specific antigen despite castrate testosterone levels, but with no evidence of distant metastasis on traditional imaging. New drugs are being developed for this disease setting; novel imaging and tumour biomarker blood tests are likely to define this disease state more accurately.

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

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

Metastatic Castration-Sensitive Prostate Cancer: Optimizing Patient Selection and Treatment

The treatment landscape for metastatic castration-sensitive prostate cancer (mCSPC) has rapidly evolved over the past 5 years. Although androgen-deprivation therapy (ADT) is still the backbone of treatment, the addition of docetaxel or abiraterone acetate has improved outcomes for patients with mCSPC and become standard of care. With multiple treatment options available for patients with mCSPC, treatment selection to optimize patient outcomes has become increasingly difficult. Here, we review the clinical trials involving ADT plus docetaxel or abiraterone and provide clinicians with guidelines for treatment. Although surgery and/or radiation are standard of care for localized, intermediate- and high-risk prostate cancer, these treatments are not routinely used as part of initial treatment plans for patients with de novo mCSPC. Recent clinical data are challenging that dogma, and we review the literature on the addition of surgery and radiation to systemic therapy for mCSPC. Finally, the standard of care for oligometastatic prostate cancer (a subset of mCSPC with limited metastases) has not been established compared with that for some other cancers. We discuss the recent studies on metastasis-directed therapy for treatment of oligometastatic prostate cancer.

Novel androgen axis systemic therapies for metastatic hormone-sensitive prostate cancer

PURPOSE OF REVIEW

Upfront docetaxel and androgen deprivation therapy (ADT) has improved outcomes over ADT alone in men with metastatic hormone-sensitive prostate cancer (mHSPC). Here in, we review the emerging role of novel androgen axis inhibitors in the treatment of men with mHSPC.

RECENT FINDINGS

Recently two studies, LATITUDE and STAMPEDE arm G, showed improved survival with addition of abiraterone acetate with prednisone or prednisolone to ADT in men with hormone-naïve advanced prostate cancer.

SUMMARY

Upfront docetaxel in addition to ADT has been shown to improve survival outcomes in men with high-volume mHSPC. Recently, abiraterone acetate and prednisone or prednisolone and ADT have been shown to improve survival outcomes compared with ADT alone in men with mHSPC. Multiple other novel androgen axis inhibitors are being investigated in this setting, and expected to garner regulatory approval in the near future. Biomarkers predicting response to these agents are urgently needed to optimize treatment selection, not only to improve outcomes but to also minimize cost and toxicities.

Does docetaxel prolong survival of patients with non-metastatic castration-resistant prostate cancer?

BACKGROUND

Guidelines define docetaxel as a first-line therapeutic option for metastatic castration-resistant prostate cancer (mCRPC). However, the role of docetaxel in non-metastatic castration-resistant prostate cancer (nmCRPC) has not been fully investigated. The aim of this retrospective study was to evaluate the potential role of docetaxel in nmCRPC. Clinical outcomes including overall survival were compared between CRPC patients who had docetaxel introduced while in nonmetastatic versus metastatic diseases.

METHODS

A total of 98 CRPC patients had docetaxel therapy. Of these 46 patients received docetaxel for nmCRPC, and 52 had distant metastases. Clinical outcomes from the time of diagnosis of CRPC were compared retrospectively between groups.

RESULTS

The median observation period after the diagnosis of CRPC in these patients was 42 months (range, 3-166). Overall survival (OS) was significantly longer in the nmCRPC group than in the mCRPC group (not reached vs 52.2 months, respectively, P = 0.006). Multivariate analysis showed that longer time to CRPC, docetaxel use in nmCRPC, and use of abiraterone acetate and/or enzalutamide were significant predictors for improved OS (P = 0.04, 0.019 and 0.002, respectively). The incidence and profile of adverse events did not differ significantly between groups.

CONCLUSIONS

Earlier induction of docetaxel in nmCRPC patients may prolong OS. Further prospective studies in more patients will be required to confirm our findings.

PP2A as the Main Node of Therapeutic Strategies and Resistance Reversal in Triple-Negative Breast Cancer

Triple negative breast cancer (TNBC), is defined as a type of tumor lacking the expression of estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER2). The ER, PR and HER2 are usually the molecular therapeutic targets for breast cancers, but they are ineffective for TNBC because of their negative expressions, so chemotherapy is currently the main treatment strategy in TNBC. However, drug resistance remains a major impediment to TNBC chemotherapeutic treatment. Recently, the protein phosphatase 2A (PP2A) has been found to regulate the phosphorylation of some substrates involved in the relevant target of TNBC, such as cell cycle control, DNA damage responses, epidermal growth factor receptor, immune modulation and cell death resistance, which may be the effective therapeutic strategies or influence drug sensitivity to TNBCs. Furthermore, PP2A has also been found that could induce ER re-expression in ER-negative breast cancer cells, and which suggests PP2A could promote the sensitivity of tamoxifen to TNBCs as a resistance reversal agent. In this review, we will summarize the potential therapeutic value of PP2A as the main node in developing targeting agents, disrupting resistance or restoring drug sensitivity in TNBC.

Newly Diagnosed Metastatic Prostate Cancer: Has the Paradigm Changed?

Androgen deprivation therapy (ADT) has been conventional treatment of newly diagnosed metastatic prostate cancer for more than 70 years. However, all patients eventually become castration-resistant and a significant proportion of life span is spent in the castration-resistant state. Prospective randomized control trials have incorporated early chemotherapy along with ADT based on the hypothesis that a significant level of resistance to ADT already exists in newly diagnosed metastatic prostate cancer and ADT exhibits synergistic antitumor activity with taxanes. We discuss the changing landscape of management of patients with newly diagnosed metastatic prostate cancer based on recently published landmark randomized trials.

Potential therapeutic targets of triple-negative breast cancer based on its intrinsic subtype

Triple-negative breast cancer (TNBC) is an aggressive subgroup of human breast cancer, which is characterized as estrogen receptor (ER) negative, progesterone receptor (PR) negative, and human epidermal growth factor receptor 2 (HER2) negative. TNBC is the most difficult breast cancer subgroup to treat, due to its unresponsiveness to current clinical targeted therapies, high rate of recurrence, and poor prognosis. Thus, there is an urgent medical need to identify therapeutic targets and develop more effective stratified medicine for the treatment of TNBC. Here we review the potential therapeutic targets for TNBC based on its intrinsic subtype. We also review the aberrant activated signals found in different subgroups of TNBC, including androgen receptor (AR) and PI3K/AKT/mTOR, Notch, Wnt/β-catenin, Hedge-hog, and TGF-β signaling pathways, which play essential roles in multiple development stages of TNBC. The careful analysis of these signaling pathways and therapeutic targets would have significant impact on the drug development and clinical trials, leading to effective therapies for this deadly disease.

Orteronel Switch Maintenance Therapy in Metastatic Castration Resistant Prostate Cancer After First-Line Docetaxel: A Multicenter, Randomized, Double-Blind, Placebo-Controlled Trial (SAKK 08/11)

BACKGROUND

We tested whether a switch maintenance treatment with orteronel, an oral inhibitor of androgen biosynthesis, prolongs disease control in men with metastatic castration-resistant prostate cancer (mCRPC) after documented disease stabilization with docetaxel.

METHODS

Men with mCRPC and non-progressive disease after a cumulative dose of ≥300 mg/m2 docetaxel for first line treatment were randomized 1:1 to receive orteronel 300 mg twice daily or placebo. The primary endpoint was event-free survival (EFS) defined as the time from randomization to death or the combination of at least two of radiographic, clinical, or PSA progression. Ninety-six patients per arm were planned to demonstrate an improvement of median EFS from 4 months on placebo to 6.7 months on orteronel (hazard ratio (HR) 0.6; type I error 5% and power 90%).

RESULTS

Forty-seven patients (23 orteronel, 24 placebo) were randomized before premature closure of the trial because of discontinuation of clinical development of orteronel. Median EFS was 8.5 months with orteronel and 2.9 months with placebo (P = 0.001; HR 0.32; 95%CI 0.15-0.65). Median radiographic progression-free survival (rPFS) was 8.5 and 2.8 months (P = 0.02; HR 0.42; 95%CI 0.20-0.91) in the orteronel and placebo arm, respectively. PSA decline ≥50% was seen in 57% on orteronel and 4% on placebo. Toxicity was mainly mild, one patient on orteronel developed transient grade 3 adrenal insufficiency and one grade 4 pneumonitis.

CONCLUSIONS

Orteronel significantly prolongs EFS in men with mCRPC who achieve disease stabilization with docetaxel. The concept of switch maintenance therapy in mCRPC warrants further research. Prostate 76:1519-1527, 2016. © 2016 Wiley Periodicals, Inc.

Progress in the mechanism and drug development of castration-resistant prostate cancer

Although prostate cancer can initially respond to androgen deprivation therapy, it will inevitably relapse and switch to a castration-resistant state. The progress in understanding the mechanism of castration-resistant prostate cancer (CRPC) has led to the evolution of novel agents, including sipuleucel-T as an immunomodulant agent, enzalutamide as an androgen receptor antagonist, docetaxel as a chemotherapeutic agent and radium-223 as a radiopharmaceutical agent. In this review, we discuss the main mechanisms of CRPC and the development of promising agents along with the novel therapies in the clinic. New therapeutic challenges remain, such as the identification of predictive biomarkers and the optimal combinations of agents. Future investigation is still needed for a better understanding of CRPC.

Phase I and II therapies targeting the androgen receptor for the treatment of castration resistant prostate cancer

INTRODUCTION

Prostate cancer is the most common cancer in elderly males. Regardless of the initial hormonal treatment in metastatic disease, a significant proportion of patients develop castration resistant prostate cancer (CRPC). A better understanding of the molecular mechanisms behind castration resistance has led to the approval of oral medications such as abiraterone acetate and enzalutamide. Relevant research is accelerated with numerous agents being tested for the management of CRPC.

AREAS COVERED

The authors present Phase I and II studies targeting the androgen receptor for the treatment of CRPC. Three groups of agents are identified according to the mechanism of action. These include the CYP-17 modulators (Orteronel, Galeterone, VT-464 and CFG-920), novel antiandrogens (Apatorsen, ARN-509, ODM-201, EZN-4176, AZD-3514) and bipolar androgen therapy.

EXPERT OPINION

Further understanding of the mechanisms leading to castration resistance in prostate cancer can reveal potential targets for the development of novel anti-cancer agents. Except for the development of novel antiandrogens and CYP-17 modulators, bipolar androgen therapy is an interesting therapeutic approach. The combinations of the novel agents tested in Phase I and II studies with established agents is another field of interest. The real challenge is to distinguish a novel anti-cancer agent with acceptable tolerability and the best outcome.

The Emerging Role of Extracellular Vesicle-Mediated Drug Resistance in Cancers: Implications in Advanced Prostate Cancer

Emerging evidence has shown that the extracellular vesicles (EVs) regulate various biological processes and can control cell proliferation and survival, as well as being involved in normal cell development and diseases such as cancers. In cancer treatment, development of acquired drug resistance phenotype is a serious issue. Recently it has been shown that the presence of multidrug resistance proteins such as Pgp-1 and enrichment of the lipid ceramide in EVs could have a role in mediating drug resistance. EVs could also mediate multidrug resistance through uptake of drugs in vesicles and thus limit the bioavailability of drugs to treat cancer cells. In this review, we discussed the emerging evidence of the role EVs play in mediating drug resistance in cancers and in particular the role of EVs mediating drug resistance in advanced prostate cancer. The role of EV-associated multidrug resistance proteins, miRNA, mRNA, and lipid as well as the potential interaction(s) among these factors was probed. Lastly, we provide an overview of the current available treatments for advanced prostate cancer, considering where EVs may mediate the development of resistance against these drugs.

Overview on the complexity of androgen receptor-targeted therapy for prostate cancer

In the past decades, the field of prostate cancer (PCa) biology has developed exponentially and paralleled with that has been the growing interest in translation of laboratory findings into clinical practice. Based on overwhelming evidence of high impact research findings which support the underlying cause of insufficient drug efficacy in patients progressing on standard androgen deprivation therapy (ADT) is due to persistent activation of the androgen receptor (AR) signaling axis. Therefore, newer agents must be discovered especially because newer ADT such as abiraterone and enzalutamide are becoming ineffective due to rapid development of resistance to these agents. High-throughput technologies are generating massive and highly dimensional genetic variation data that has helped in developing a better understanding of the dynamic repertoire of AR and AR variants. Full length AR protein and its variants modulate a sophisticated regulatory system to orchestrate cellular responses. We partition this multicomponent review into subsections addressing the underlying mechanisms of resistance to recent therapeutics, positive and negative regulators of AR signaling cascade, and how SUMOylation modulates AR induced transcriptional activity. Experimentally verified findings obtained from cell culture and preclinical studies focusing on the potential of natural agents in inhibiting mRNA/protein levels of AR, nuclear accumulation and enhanced nuclear export of AR are also discussed. We also provide spotlight on molecular basis of enzalutamide resistance with an overview of the strategies opted to overcome such resistance. AR variants are comprehensively described and different mechanisms that regulate AR variant expression are also discussed. Reconceptualization of phenotype- and genotype-driven studies have convincingly revealed that drug induced resistance is a major stumbling block in standardization of therapy. Therefore, we summarize succinctly the knowledge of drug resistance especially to ADT and potential avenues to overcome such resistance for improving the treatment outcome of PCa patients.

Phase III, randomized, double-blind, multicenter trial comparing orteronel (TAK-700) plus prednisone with placebo plus prednisone in patients with metastatic castration-resistant prostate cancer that has progressed during or after docetaxel-based therapy: ELM-PC 5

PURPOSE

Orteronel (TAK-700) is an investigational, nonsteroidal, reversible, selective 17,20-lyase inhibitor. This study examined orteronel in patients with metastatic castration-resistant prostate cancer that progressed after docetaxel therapy.

PATIENTS AND METHODS

In our study, 1,099 men were randomly assigned in a 2:1 schedule to receive orteronel 400 mg plus prednisone 5 mg twice daily or placebo plus prednisone 5 mg twice daily, stratified by region (Europe, North America [NA], and non-Europe/NA) and Brief Pain Inventory-Short Form worst pain score. Primary end point was overall survival (OS). Key secondary end points (radiographic progression-free survival [rPFS], ≥ 50% decrease of prostate-specific antigen [PSA50], and pain response at 12 weeks) were to undergo statistical testing only if the primary end point analysis was significant.

RESULTS

The study was unblinded after crossing a prespecified OS futility boundary. The median OS was 17.0 months versus 15.2 months with orteronel-prednisone versus placebo-prednisone (hazard ratio [HR], 0.886; 95% CI, 0.739 to 1.062; P = .190). Improved rPFS was observed with orteronel-prednisone (median, 8.3 v 5.7 months; HR, 0.760; 95% CI, 0.653 to 0.885; P < .001). Orteronel-prednisone showed advantages over placebo-prednisone in PSA50 rate (25% v 10%, P < .001) and time to PSA progression (median, 5.5 v 2.9 months, P < .001) but not pain response rate (12% v 9%; P = .128). Adverse events (all grades) were generally more frequent with orteronel-prednisone, including nausea (42% v 26%), vomiting (36% v 17%), fatigue (29% v 23%), and increased amylase (14% v 2%).

CONCLUSION

Our study did not meet the primary end point of OS. Longer rPFS and a higher PSA50 rate with orteronel-prednisone indicate antitumor activity.

ODM-201: a new-generation androgen receptor inhibitor in castration-resistant prostate cancer

Androgen deprivation therapy is the standard of care for patients with advanced hormone-sensitive prostate cancer. Despite an initial response, most patients progress to castration-resistant prostate cancer (CRPC). The realization that CRPC remains driven by androgen receptor (AR) signaling has formed the basis for a new generation of agents targeting the AR axis. Two of these agents, abiraterone acetate and enzalutamide, have been shown to prolong overall survival in patients with CRPC. Several other AR inhibitors are currently in development for the treatment of CRPC. The present article reviews ODM-201, a new-generation AR inhibitor with a unique molecular structure, in the treatment of CRPC. The design of an ongoing Phase III trial (ARAMIS) of ODM-201 in men with non-metastatic CRPC is also discussed, at a disease stage for which there is currently no approved treatment.

Molecular pathways and targets in prostate cancer

Prostate cancer co-opts a unique set of cellular pathways in its initiation and progression. The heterogeneity of prostate cancers is evident at earlier stages, and has led to rigorous efforts to stratify the localized prostate cancers, so that progression to advanced stages could be predicted based upon salient features of the early disease. The deregulated androgen receptor signaling is undeniably most important in the progression of the majority of prostate tumors. It is perhaps because of the primacy of the androgen receptor governed transcriptional program in prostate epithelium cells that once this program is corrupted, the consequences of the ensuing changes in activity are pleotropic and could contribute to malignancy in multiple ways. Following localized surgical and radiation therapies, 20-40% of patients will relapse and progress, and will be treated with androgen deprivation therapies. The successful development of the new agents that inhibit androgen signaling has changed the progression free survival in hormone resistant disease, but this has not changed the almost ubiquitous development of truly resistant phenotypes in advanced prostate cancer. This review summarizes the current understanding of the molecular pathways involved in localized and metastatic prostate cancer, with an emphasis on the clinical implications of the new knowledge.