Should docetaxel be standard of care for patients with metastatic hormone-sensitive prostate cancer? Pro and contra

Management of Advanced Prostate Cancer With Relugolix: Illustrative Case Scenarios From an Advanced Practice Provider Perspective

Prostate cancer is the second most common cause of cancer-related mortality among men in the United States, with an estimated 34,700 deaths annually. Androgen deprivation therapy (ADT) is the cornerstone of advanced prostate cancer therapy, and injectable luteinizing hormone-releasing hormone (LHRH) agonists have served as the most commonly used ADT for over 30 years. Relugolix, a first-in-class, once-daily, oral gonadotropin-releasing hormone (GnRH) antagonist, was developed to address some of the limitations of available ADT therapies. Herein, we present two hypothetical case reports via an advanced practice provider (APP) perspective that reflect prototypical examples of patients with advanced localized disease not suitable for surgery or newly diagnosed hormone-sensitive metastatic disease treated with relugolix. The cases presented are meant to be instructional and within the scope of the current approved prescribing information for all medications mentioned. Best practices from an APP perspective are shared.

Trends in the Use of Second-Generation Androgen Receptor Axis Inhibitors for Metastatic Hormone-Sensitive Prostate Cancer and Clinical Factors Predicting Biological Recurrence

The advent of second-generation androgen receptor axis-targeted agents (ARATs) has revolutionized the treatment of metastatic hormone-sensitive prostate cancer (mHSPC). Biochemical recurrence-free survival (BRFS) was used to compare the efficacy of each ARAT. This multicenter retrospective study included 581 patients with newly diagnosed mHSPC who received first-line hormone therapy. The characteristics of patients treated with different ARATs were compared as well as changes in the usage of each drug over time. For BRFS, the apalutamide (Apa) and enzalutamide (Enza) groups, as well as the abiraterone acetate (Abi) and Apa/Enza groups, were compared. In addition, multivariate analysis was performed to determine predictive factors for biochemical recurrence (BCR). The use of second-generation ARATs tended to increase after May 2020. No significant difference in BRFS was found between patients receiving Apa and Enza (p = 0.490) and those receiving Abi or Apa/Enza (p = 0.906). Multivariate analysis revealed that the neutrophil-to-lymphocyte ratio (NLR) ≥ 2.76 and PSA ≥ 0.550 ng/mL were independent predictors of BCR. There were no significant differences in patient characteristics or BRFS in patients with mHSPC receiving different ARATs as first-line treatment. NLR and PSA may be prognostic factors following the first-line treatment of patients with mHSPC.

SGK2 promotes prostate cancer metastasis by inhibiting ferroptosis via upregulating GPX4

Recent research has shown that ferroptosis, the iron-dependent accumulation of lipid peroxides that leads to cell death, suppresses cancer metastasis. However, the role of ferroptosis in prostate cancer metastasis has not been completely elucidated. In the current study, we identified the essential role of serum/glucocorticoid regulated kinase 2 (SGK2) in promoting prostate cancer metastasis by inhibiting ferroptosis. We found that the expression of SGK2 was higher in metastatic prostate cancer and predicted poor clinical outcomes. SGK2 knockdown inhibited the metastatic capacity of prostate cancer cells in vivo and in vitro, while SGK2 overexpression inhibited ferroptosis and facilitated prostate cancer metastasis by phosphorylating the Thr-24 and Ser-319 sites of forkhead box O1 (FOXO1). This process induced the translocation of FOXO1 from the nucleus to the cytoplasm, relieving the inhibitory effect of FOXO1 on glutathione peroxidase 4 (GPX4). These findings delineated a novel role of SGK2 in ferroptosis regulation of prostate cancer metastasis, identifying a new key pathway driving prostate cancer metastasis and potentially providing new treatment strategies for metastatic prostate cancer.

Current status and future perspective on the management of metastatic castration-sensitive prostate cancer

Since 1941, the standard treatment for metastatic castration-sensitive prostate cancer (mCSPC) was androgen deprivation therapy (ADT) by surgical or medical castration with or without first-generation antiandrogen. However, the efficacy of ADT does not last in most cases. In the 2010s, de-intensification by intermittent ADT was evaluated by RCTs for mCSPC to mitigate the treatment-emerged burdens. However, intermittent ADT failed to show non-inferiority in OS for mCSPC and is an optional treatment for selected patients with mCSPC. The treatment for patients with mCSPC has improved in the last years. Currently, based on the evidence from RCTs, intensification treatment by adding docetaxel, novel androgen receptor pathway inhibitors and multimodal treatment using radiotherapy to the primary have become new standard treatments for mCSPC. Furthermore, ongoing RCTs have been investigating the clinical values of more intensified treatments by combining multiple effective treatment for mCSPC. In addition, novel treatment using immunotherapeutics such as anti-PD-1 antibody and precision medicine approach using novel imaging and genomic marker has been investigated vigorously. Thus, we review current treatment evidence obtained by RCTs that included patients with mCSPC. The future key to mCSPC treatment could be personalized medicine including translational and clinical medicine aspects, with molecular testing to assess the biological tumor behavior to optimize clinical decision-making.

Multisite Radiotherapy Combined With Tislelizumab for Metastatic Castration-Resistant Prostate Cancer With Second-Line and Above Therapy Failure: Study Protocol for an Open-Label, Single-Arm, Phase Ib/II Study

Background

Tislelizumab combined with radiotherapy as a salvage treatment for patients with end-stage metastatic castration-resistant prostate cancer (mCRPC) is not reported. This study aimed to describe a protocol to evaluate the safety and efficacy of multisite radiotherapy combined with tislelizumab as a salvage therapy for mCRPC in patients who had at least one second-line treatment failure.

Methods

The study included patients with mCRPC who had at least one lesion suitable for radiotherapy and failed androgen deprivation therapy (ADT), followed by at least one novel second-line endocrine therapy. All patients received tislelizumab monotherapy induction therapy for two cycles, then combined with multisite radiotherapy for one cycle, followed by tislelizumab maintenance therapy, until either disease progressed or the patient developed unacceptable toxicity. Radiation methods and lesions were individually selected according to the specified protocol. Primary endpoints included safety and objective response rate. Secondary endpoints included prostate-specific antigen (PSA) response rate, disease control rate, overall survival, radiographic progression-free survival (rPFS), and biochemical progression-free survival (bPFS). Furthermore, the exploratory endpoints included the identification of the predictive biomarkers and exploration of the correlation between biomarkers and the tumor response to the combined regimen.

Discussion

This study included three treatment stages to evaluate the efficacy of immunotherapy and the combination of immunotherapy and radiotherapy for patients with mCRPC who have had at least second-line treatment failure. Additionally, radiation-related and immune-related early and late toxicities were determined, respectively. Furthermore, the study also aimed to identify the predictive biomarkers associated with immunotherapy for treating mCRPC.

Trial Registration

https://www.chictr.org.cn/showproj.aspx?proj=126359, identifier ChiCTR2100046212.

Systemic Triple Therapy in Metastatic Hormone-Sensitive Prostate Cancer (mHSPC): Ready for Prime Time or Still to Be Explored?

For decades, mono androgen deprivation therapy (ADT) has been the gold standard for metastatic hormone-sensitive prostate cancer (mHSPC) treatment. Several studies have been published within the last seven years demonstrating a significant survival advantage by combination treatment with standard ADT plus docetaxel or androgen receptor-axis-targeted therapy (ARAT) compared to ADT monotherapy. As a result, overall survival can be prolonged by at least 18 months. Recently published congress data of the PEACE-1 study suggests that in the future, triple therapy might be the new gold standard. In addition to this study, which has shown that triple treatment with standard ADT plus docetaxel plus abiraterone is superior to standard ADT plus docetaxel, several other phase III triple therapy studies are currently ongoing. The different modes of action that are investigated reach from AR-targeting over mitotic inhibition and immunotherapy to PARP and AKT inhibition. In this review we will explore if triple therapy has the potential to be the new standard for mHSPC treatment in the near future.

Efficacy of enzalutamide in subgroups of men with metastatic hormone-sensitive prostate cancer based on prior therapy, disease volume, and risk

BACKGROUND

While enzalutamide plus androgen deprivation therapy (ADT) significantly reduces the risk of radiographic progression-free survival (rPFS) and improves overall survival in metastatic hormone-sensitive prostate cancer (mHSPC), the efficacy in clinically relevant subgroups of patients based on prior local and systemic therapy, disease volume, and risk has not been analyzed to date. These post hoc analyses of the phase 3 ARCHES trial (NCT02677896) evaluated the efficacy of enzalutamide plus ADT according to prior local and systemic treatment, disease volume, and risk, assessed at trial baseline.

METHODS

In ARCHES, a global, double-blind, placebo-controlled, phase 3 study, 1150 patients with mHSPC were randomized 1:1 to receive enzalutamide (160 mg/day) plus ADT or placebo plus ADT, stratified by prior docetaxel therapy and disease volume. Primary endpoint was rPFS. Secondary endpoints included time to prostate-specific antigen progression, symptomatic skeletal events, and prostate-specific antigen and radiographic responses. Analyses of clinical endpoints were completed by prior local therapy, prior docetaxel exposure, CHAARTED (NCT00309985)-defined disease volume, and LATITUDE (NCT01715285)-defined risk groups.

RESULTS

Patients were randomized to enzalutamide plus ADT (n = 574) and placebo plus ADT (n = 576). Enzalutamide plus ADT significantly improved rPFS (hazard ratio: 0.39; p < 0.0001), with similar improvements reported in all subgroups based on prior local and docetaxel treatment, disease volume, and risk. Treatment benefits were observed with enzalutamide plus ADT in multiple secondary clinical endpoints in the overall population and all subgroups.

CONCLUSIONS

Enzalutamide plus ADT demonstrated clinical benefit across all patients with mHSPC, irrespective of prior local and systemic treatment, disease volume, and risk.

Treatment and resistance mechanisms in castration-resistant prostate cancer: new implications for clinical decision making?

Introduction: The armamentarium of treatment options in metastatic and non-metastatic CRPC is rapidly evolving. However, the question of how individual treatment decisions should be balanced by available predictive clinical parameters, pharmacogenetic and drug interaction profiles, or compound-associated molecular biomarkers is a major challenge for clinical practice.Areas covered: We discuss treatment and resistance mechanisms in PC with regard to their association to drug efficacy and tolerability. Current efforts of combination treatment and putative predictive biomarkers of available and upcoming compounds are highlighted with regard to their implication on clinical decision-making.Expert opinion: Several treatment approaches are delineated, where identification of resistance mechanisms in CRPC may guide treatment selection. To date, most of these candidate biomarkers will however be found only in a small subset of patients. While current approaches of combination treatment in CRPC are proving synergistic effects on cancer biology, higher complexity with regard to biomarker analysis and interaction profiles of the respective compounds may be expected. Among other aspects of personalized treatment, consideration of drug-drug interaction and pharmacogenetics is an underrepresented issue. However, the non-metastatic castration resistant prostate cancer situation may be an example for treatment selection based on drug interaction profiles in the future.

Enzalutamide plus androgen-deprivation therapy in hormone-sensitive prostate cancer: new perspectives from a current Phase III clinical trial

Prostate cancer is a major health issue with an incidence of 1,100,000 worldwide. Eventually, 20-40% of curatively treated patients will face a biochemical recurrence. Lately, the treatment options in metastasized hormone sensitive prostate cancer (mHSPC) were rapidly evolving after years of stagnation. Encouraging results in clinical trials of combination treatment of androgen deprivation therapy with either chemotherapy or second-generation hormonal treatment indicate a paradigm shift in this clinical scenario. In the light of this, the current review is focusing on the concept and initial results of the Phase III (ARCHES) trial investigating enzalutamide plus androgen deprivation therapy in mHSPC. Moreover, a comprehensive appraisal of the expanding landscape of systemic therapies for mHSPC is provided.

Using medical claims database to develop a population disease progression model for leuprorelin-treated subjects with hormone-sensitive prostate cancer

Androgen deprivation therapy (ADT) is a widely used treatment for patients with hormone-sensitive prostate cancer (PCa). However, duration of treatment response varies, and most patients eventually experience disease progression despite treatment. Leuprorelin is a luteinizing hormone-releasing hormone (LHRH) agonist, a commonly used form of ADT. Prostate-specific antigen (PSA) is a biomarker for monitoring disease progression and predicting treatment response and survival in PCa. However, time-dependent profile of tumor regression and growth in patients with hormone-sensitive PCa on ADT has never been fully characterized. In this analysis, nationwide medical claims database provided by Humana from 2007 to 2011 was used to construct a population-based disease progression model for patients with hormone-sensitive PCa on leuprorelin. Data were analyzed by nonlinear mixed effects modeling utilizing Monte Carlo Parametric Expectation Maximization (MCPEM) method in NONMEM. Covariate selection was performed using a modified Wald’s approximation method with backward elimination (WAM-BE) proposed by our group. 1113 PSA observations from 264 subjects with malignant PCa were used for model development. PSA kinetics were well described by the final covariate model. Model parameters were well estimated, but large between-patient variability was observed. Hemoglobin significantly affected proportion of drug-resistant cells in the original tumor, while baseline PSA and antiandrogen use significantly affected treatment effect on drug-sensitive PCa cells (Ds). Population estimate of Ds was 3.78 x 10⁻² day^-1. Population estimates of growth rates for drug-sensitive (Gs) and drug-resistant PCa cells (G_R) were 1.96 x 10⁻³ and 6.54 x 10⁻⁴ day^-1, corresponding to a PSA doubling time of 354 and 1060 days, respectively. Proportion of the original PCa cells inherently resistant to treatment was estimated to be 1.94%. Application of population-based disease progression model to clinical data allowed characterization of tumor resistant patterns and growth/regression rates that enhances our understanding of how PCa responds to ADT.

No survival benefit found after extended treatment with docetaxel for patients with castration-resistant prostate cancer

BACKGROUND

Docetaxel (DOC) has been widely accepted as a therapeutic option for castration-resistant prostate cancer (CRPC). Evidence-based clinical guidelines have stipulated its use up to 10 cycles in most health care systems. There has been a paucity of information regarding potential benefits of its use over 10 cycles. The purpose of this study is to re-examine the rationale for the clinical guidelines concerning cycles of DOC in CRPC.

METHODS

Between July 2007 and July 2016, a total of 122 CRPC patients received at least five cycles of DOC at Jikei University and its affiliate hospitals. Doses of DOC (75 mg/m ² ) were administered every 3 to 4 weeks. Clinical outcomes between patients receiving extended cycles of DOC (≥11 cycles, extended [ex]-DOC group) were compared to those receiving fewer (≤10 cycles, short-DOC group). A subgroup of patients who had discontinued DOC owing to adverse events, but whose disease did not progress, were also considered for comparison (adverse events [AE] group). Overall survival from the induction of DOC was the primary outcome measure. Univariate and multivariate analyses were conducted to analyze variables associated with overall survival.

RESULTS

The ex- and short-DOC groups included 80 and 42 patients, respectively. Most baseline demographics did not differ between groups. However, in the short-DOC group more patients had received abiraterone acetate and/or enzalutamide before chemotherapy, age at DOC induction was younger, and lactate dehydrogenase at DOC induction was higher. Overall survival was significantly longer in the ex-DOC group compared to the short-DOC group (median, 53 and 27 months, respectively; P = .04). A subgroup of 22 patients in AE group was compared to compensate for potential bias. Overall survival from the induction of DOC was comparable between AE group and ex-DOC groups (median, 53 vs 53 months, respectively; P = 0.87). Univariate and multivariate analyses did not show any advantage of extended use of DOC on patient survival.

CONCLUSIONS

The results of this study failed to show the survival benefit of extended use of DOC over 10 cycles in CRPC patients in the era of innovative drugs such as abiraterone acetate, enzalutamide, and cabazitaxel. Further prospective studies are required to confirm our findings.

Comparison Between Prognostic Classifications in De Novo Metastatic Hormone Sensitive Prostate Cancer

BACKGROUND

The CHAARTED and LATITUDE trials demonstrated improved outcomes with docetaxel or abiraterone plus androgen deprivation therapy in metastatic hormone sensitive prostate cancer (mHSPC) using two different prognostic scores.

OBJECTIVE

The aim of our study was to assess the concordance between the two scores and if these retained their prognostic value exclusively in de novo mHSPC.

PATIENTS AND METHODS

De novo mHSPC patients referring to our institution were retrospectively stratified according to the CHAARTED and LATITUDE classifications: high volume/high risk (HV/HR), low-volume/low-risk (LV/LR), and HVorHR (HV/LR and LV/HR). The Kaplan-Meier method and Cox proportional-hazard models were used to estimate hazard ratios for overall survival.

RESULTS

The study population included 106 patients. Concordance between the CHAARTED and LATITUDE classifications was observed in 86.8% of cases (65.1% HV/HR, 21.7% LV/LR), while 13.2% of patients fulfill the criteria of only one of the two classifications (HVorHR). When analyzed independently, the CHAARTED and LATITUDE classifications maintained their prognostic value (mOS 28.2 months in HV versus 60.9 months in LV, p = 0.006; 28.2 months in HR versus 40.6 months in LR, p = 0.017). The LR/LV population showed significantly longer mOS compared to the HR/HV group (72.6 months versus 26.3 months; p = 0.005), and to HVorHR patients (35.1 months; p = 0.003). No difference in OS was observed between HV/HR and HVorHR patients. ECOG PS ≥ 1 and patient age improved the prognostic value of the two classifications with multivariate analysis.

CONCLUSIONS

Our study showed a lack of complete concordance between the CHAARTED and LATITUDE classifications. The analysis confirmed the role of these prognostic scores to stratify de novo mHSPC patients in clinical practice.

ARCHES: A Randomized, Phase III Study of Androgen Deprivation Therapy With Enzalutamide or Placebo in Men With Metastatic Hormone-Sensitive Prostate Cancer

PURPOSE

Enzalutamide, a potent androgen-receptor inhibitor, has demonstrated significant benefits in metastatic and nonmetastatic castration-resistant prostate cancer. We evaluated the efficacy and safety of enzalutamide in metastatic hormone-sensitive prostate cancer (mHSPC).

METHODS

ARCHES (ClinicalTrials.gov identifier: NCT02677896) is a multinational, double-blind, phase III trial, wherein 1,150 men with mHSPC were randomly assigned 1:1 to enzalutamide (160 mg/day) or placebo, plus androgen deprivation therapy (ADT), stratified by disease volume and prior docetaxel chemotherapy. The primary end point was radiographic progression-free survival.

RESULTS

As of October 14, 2018, the risk of radiographic progression or death was significantly reduced with enzalutamide plus ADT versus placebo plus ADT (hazard ratio, 0.39; 95% CI, 0.30 to 0.50; P < .001; median not reached v 19.0 months). Similar significant improvements in radiographic progression-free survival were reported in prespecified subgroups on the basis of disease volume and prior docetaxel therapy. Enzalutamide plus ADT significantly reduced the risk of prostate-specific antigen progression, initiation of new antineoplastic therapy, first symptomatic skeletal event, castration resistance, and reduced risk of pain progression. More men achieved an undetectable prostate-specific antigen level and/or an objective response with enzalutamide plus ADT (P < .001). Patients in both treatment groups reported a high baseline level of quality of life, which was maintained over time. Grade 3 or greater adverse events were reported in 24.3% of patients who received enzalutamide plus ADT versus 25.6% of patients who received placebo plus ADT, with no unexpected adverse events.

CONCLUSION

Enzalutamide with ADT significantly reduced the risk of metastatic progression or death over time versus placebo plus ADT in men with mHSPC, including those with low-volume disease and/or prior docetaxel, with a safety analysis that seems consistent with the safety profile of enzalutamide in previous clinical trials in castration-resistant prostate cancer.

Apalutamide for Metastatic, Castration-Sensitive Prostate Cancer

BACKGROUND

Apalutamide is an inhibitor of the ligand-binding domain of the androgen receptor. Whether the addition of apalutamide to androgen-deprivation therapy (ADT) would prolong radiographic progression-free survival and overall survival as compared with placebo plus ADT among patients with metastatic, castration-sensitive prostate cancer has not been determined.

METHODS

In this double-blind, phase 3 trial, we randomly assigned patients with metastatic, castration-sensitive prostate cancer to receive apalutamide (240 mg per day) or placebo, added to ADT. Previous treatment for localized disease and previous docetaxel therapy were allowed. The primary end points were radiographic progression-free survival and overall survival.

RESULTS

A total of 525 patients were assigned to receive apalutamide plus ADT and 527 to receive placebo plus ADT. The median age was 68 years. A total of 16.4% of the patients had undergone prostatectomy or received radiotherapy for localized disease, and 10.7% had received previous docetaxel therapy; 62.7% had high-volume disease, and 37.3% had low-volume disease. At the first interim analysis, with a median of 22.7 months of follow-up, the percentage of patients with radiographic progression-free survival at 24 months was 68.2% in the apalutamide group and 47.5% in the placebo group (hazard ratio for radiographic progression or death, 0.48; 95% confidence interval [CI], 0.39 to 0.60; P<0.001). Overall survival at 24 months was also greater with apalutamide than with placebo (82.4% in the apalutamide group vs. 73.5% in the placebo group; hazard ratio for death, 0.67; 95% CI, 0.51 to 0.89; P = 0.005). The frequency of grade 3 or 4 adverse events was 42.2% in the apalutamide group and 40.8% in the placebo group; rash was more common in the apalutamide group.

CONCLUSIONS

In this trial involving patients with metastatic, castration-sensitive prostate cancer, overall survival and radiographic progression-free survival were significantly longer with the addition of apalutamide to ADT than with placebo plus ADT, and the side-effect profile did not differ substantially between the two groups. (Funded by Janssen Research and Development; TITAN ClinicalTrials.gov number, NCT02489318.).

Treatment of hormone-naïve metastatic prostate cancer

PURPOSE OF REVIEW

Until 2015, androgen deprivation therapy (ADT) alone was the standard-of-care for metastatic hormone-naïve prostate cancer (mHNPC). In the last decade, important landmark therapeutic advances occurred in the management of these patients permitting improvement of their survival.

RECENT FINDINGS

At least two prospective randomized trials proved upfront docetaxel (DOC) + ADT benefit consequently providing strong evidence for guidelines modifications. Second, similar benefit results were demonstrated when using upfront abiraterone acetate + ADT in mHNPC.

SUMMARY

Both DOC-based chemotherapy and abiraterone acetate provide survival improvement when added to ADT in mHNPC. In the current article, we review the evidence behind this progress and discuss ongoing clinical controversies.

Contemporary Management of the Newly Diagnosed Prostate Cancer Patient with Metastatic Disease at Presentation

PURPOSE OF REVIEW

Androgen deprivation therapy (ADT) has been the standard-of-care (SOC) for metastatic hormone-sensitive prostate cancer (mHSPC) since the middle of the twentieth century. Recently, several practice-changing trials have added new therapy options for these patients. Here we review these studies and discuss guidelines on treatment decision-making.

RECENT FINDINGS

A trio of studies (GETUG-AFU15, STAMPEDE, CHAARTED) combining docetaxel chemotherapy with ADT all showed clinical benefit of the addition. More recently, the LATITUDE and STAMPEDE-Abiraterone studies established yet another new option for up-front treatment of newly diagnosed metastatic prostate cancer, showing significantly prolonged overall survival (OS) and progression-free survival (PFS) compared to ADT alone in men with high-risk mHSPC. With the recent demonstration that adding either docetaxel or abiraterone plus prednisone to ADT significantly improves survival in mHSPC, physicians are confronted by a growing body of clinical data and treatment regimens. Men with high-volume and/or high-risk metastatic disease should not be treated with ADT alone without strong consideration of docetaxel or abiraterone. The choice of a first-line therapy should be made based on risk stratification, patients' comorbidities, toxicities, quality-of-life (QOL) considerations, and cost.

Abiraterone plus Prednisone in Metastatic, Castration-Sensitive Prostate Cancer

BACKGROUND

Abiraterone acetate, a drug that blocks endogenous androgen synthesis, plus prednisone is indicated for metastatic castration-resistant prostate cancer. We evaluated the clinical benefit of abiraterone acetate plus prednisone with androgen-deprivation therapy in patients with newly diagnosed, metastatic, castration-sensitive prostate cancer.

METHODS

In this double-blind, placebo-controlled, phase 3 trial, we randomly assigned 1199 patients to receive either androgen-deprivation therapy plus abiraterone acetate (1000 mg daily, given once daily as four 250-mg tablets) plus prednisone (5 mg daily) (the abiraterone group) or androgen-deprivation therapy plus dual placebos (the placebo group). The two primary end points were overall survival and radiographic progression-free survival.

RESULTS

After a median follow-up of 30.4 months at a planned interim analysis (after 406 patients had died), the median overall survival was significantly longer in the abiraterone group than in the placebo group (not reached vs. 34.7 months) (hazard ratio for death, 0.62; 95% confidence interval [CI], 0.51 to 0.76; P<0.001). The median length of radiographic progression-free survival was 33.0 months in the abiraterone group and 14.8 months in the placebo group (hazard ratio for disease progression or death, 0.47; 95% CI, 0.39 to 0.55; P<0.001). Significantly better outcomes in all secondary end points were observed in the abiraterone group, including the time until pain progression, next subsequent therapy for prostate cancer, initiation of chemotherapy, and prostate-specific antigen progression (P<0.001 for all comparisons), along with next symptomatic skeletal events (P=0.009). These findings led to the unanimous recommendation by the independent data and safety monitoring committee that the trial be unblinded and crossover be allowed for patients in the placebo group to receive abiraterone. Rates of grade 3 hypertension and hypokalemia were higher in the abiraterone group.

CONCLUSIONS

The addition of abiraterone acetate and prednisone to androgen-deprivation therapy significantly increased overall survival and radiographic progression-free survival in men with newly diagnosed, metastatic, castration-sensitive prostate cancer. (Funded by Janssen Research and Development; LATITUDE ClinicalTrials.gov number, NCT01715285 .).

Precision medicine based on epigenomics: the paradigm of carcinoma of unknown primary

Epigenetic alterations are a common hallmark of human cancer. Single epigenetic markers are starting to be incorporated into clinical practice; however, the translational use of these biomarkers has not been validated at the 'omics' level. The identification of the tissue of origin in patients with cancer of unknown primary (CUP) is an example of how epigenomics can be incorporated in clinical settings, addressing an unmet need in the diagnostic and clinical management of these patients. Despite the great diagnostic advances made in the past decade, the use of traditional diagnostic procedures only enables the tissue of origin to be determined in ∼30% of patients with CUP. Thus, development of molecularly guided diagnostic strategies has emerged to complement traditional procedures, thereby improving the clinical management of patients with CUP. In this Review, we present the latest data on strategies using epigenetics and other molecular biomarkers to guide therapeutic decisions involving patients with CUP, and we highlight areas warranting further research to engage the medical community in this unmet need.

Piecing the puzzle together: Docetaxel cycles and current considerations in the treatment of metastatic castration-resistant prostate cancer

Docetaxel is the current first line therapy for metastatic castration-resistant prostate cancer (mCRPC), but there is no standard number of docetaxel cycles given to patients. In their post hoc analysis of the Mainsail study, de Morrée et al. show that the number of docetaxel cycles administered to a patient is a significant factor contributing to overall survival. These findings warrant further investigation into the standardization of the number of docetaxel cycles administered.

Role of systemic chemotherapy in metastatic hormone-sensitive prostate cancer

INTRODUCTION

Patients with metastatic hormone sensitive prostate cancer (mHSPC) have traditionally been treated with androgen deprivation therapy (ADT). Recently, there has been a demonstration of a survival benefit with the addition of docetaxel to ADT from three large randomized controlled trials. This review summarizes these trials, draws comparisons between the trials, and attempts to provide critical evidence-based recommendation on the role of docetaxel in mHSPC.

METHODS

Of the two published (GETUG-AFU, Chemo-Hormonal therapy vs. Androgen Ablation Randomized Trial for Extensive Disease in prostate cancer [CHAARTED]) and one presented trial (STAMPEDE) an analysis of the study design, patient characteristics, outcomes, variables, and a critical comparison between the trials was performed for making practice recommendations.

RESULTS

All the three trials demonstrated statistically significant progression free survival with the addition of docetaxel to ADT in mHSPC. However, while CHAARTED trial demonstrated a significant survival benefit with addition of docetaxel to ADT in patients with high volume mHSPC, GETUG-AFU failed to demonstrate statistically significant survival benefit although there was an absolute difference in survival between the two arms, with lower sample size and statistical power compared to CHAARTED. The largest study, STAMPEDE, reported a 22 month survival benefit in patients with M1 disease with statistical significance; with subgroup analysis of high volume and low volume disease patients yet to be reported.

CONCLUSION

After a careful comparison between the trials, we conclude that systemic docetaxel chemotherapy within 4 months of initiating ADT for metastatic, high-volume HSPC should be considered the standard of care for patients with good performance status.

Efficacy and Safety of Combined Androgen Deprivation Therapy (ADT) and Docetaxel Compared with ADT Alone for Metastatic Hormone-Naive Prostate Cancer: A Systematic Review and Meta-Analysis

OBJECTIVE

Prostate cancer is the most common nonskin cancer and second most common cause of cancer mortality in older men in the United States (USA) and Western Europe. Androgen-deprivation therapy alone (ADT) remains the first line of treatment in most cases, for metastatic disease. We performed a systematic review and meta-analysis of all randomized controlled trials (RCT) that compared the efficacy and adverse events profile of a chemohormonal therapy (ADT ± docetaxel) for metastatic hormone-naive prostate cancer (mHNPC).

METHODS

Several databases were searched, including MEDLINE, EMBASE, LILACS, and CENTRAL. The primary endpoint was overall survival. Data extracted from the studies were combined by using the hazard ratio (HR) or risk ratio (RR) with their corresponding 95% confidence intervals (95% CI).

RESULTS

The final analysis included 3 trials comprising 2,264 patients (mHNPC). Patients who received the chemohormonal therapy had a longer clinical progression-free survival interval (HR = 0.64; 95% CI: 0.55 to 0.75; p<0.00001), and no heterogeneity (Chi2 = 0.64; df = 1 [p = 0.42]; I2 = 0%). The biochemical progression-free survival (bPFS) also was higher in patients treated with ADT plus docetaxel (HR = 0.63; 95% CI: 0.57 to 0.69; p<0.00001), also with no heterogeneity noted (Chi2 = 0.48; df = 2 [p = 0.79]; I2 = 0%). Finally, the combination of ADT with docetaxel showed a superior overall survival (OS) compared with ADT alone (HR = 0.73; 95% CI: 0.64 to 0.84; p<0.0001), with moderate heterogeneity (Chi2 = 3.84; df = 2 [p = 0.15]; I2 = 48%). A random-effects model analysis was performed, and the results remained favorable to the use of ADT plus docetaxel (HR = 0.73; 95% CI: 0.60 to 0.89; p = 0.002). In the final combined analysis of the high-volume disease patients, the use of the combination therapy also favored an increased overall survival (HR = 0.67; 95% CI: 0.54 to 0.83; p = 0.0003). Regarding adverse events and severe toxicity (grade ≥3), the group receiving the combined therapy had higher rates of neutropenia, febrile neutropenia and fatigue.

CONCLUSION

The combination of ADT with docetaxel improved the clinical progression-free survival, bPFS and OS of patients with mHNPC. A superior OS was seen especially for patients with metastatic and high-volume disease. This contemporary combination therapy may now be offered as a first-line treatment for selected patients.

Cost-effectiveness analysis of additional docetaxel for metastatic hormone-sensitive prostate cancer treated with androgen-deprivation therapy from a Chinese perspective

The E3805 (CHAARTED) study found that docetaxel combined with androgen-deprivation therapy (ADT) significantly improved overall survival of patients with metastatic hormone-sensitive prostate cancer. This study aims to determine whether docetaxel combined with ADT is a cost-effective strategy for advanced prostate cancer in China. According to the E3805 study, two groups (docetaxel + ADT and ADT alone) and three health states [progression-free survival (PFS), progressive disease (PD) and death] were analysed in a Markov model. All medical costs were calculated from the Chinese societal perspective. Quality-adjusted life year (QALY) and incremental cost-effectiveness ratios (ICERs) were applied as the primary outcome. Overall, the addition of docetaxel was estimated to increase the cost by $12 816.93, with a gain of 0.48 QALY. Additionally, for patients with high-volume disease, the increased cost and effectiveness were $14 627.75 and 0.69 QALYs in docetaxel + ADT group versus the ADT alone group, and the ICER was $21 199.63 per QALY. These ICERs are far more than the commonly accepted willingness-to-pay (WTP) threshold of $20 301 per QALY in China. In spite of longer survival time, docetaxel combined with ADT is not a recommended cost-effective treatment for metastatic hormone-sensitive prostate cancer in the Chinese setting.

Addition of docetaxel or bisphosphonates to standard of care in men with localised or metastatic, hormone-sensitive prostate cancer: a systematic review and meta-analyses of aggregate data

BACKGROUND

Results from large randomised controlled trials combining docetaxel or bisphosphonates with standard of care in hormone-sensitive prostate cancer have emerged. In order to investigate the effects of these therapies and to respond to emerging evidence, we aimed to systematically review all relevant trials using a framework for adaptive meta-analysis.

METHODS

For this systematic review and meta-analysis, we searched MEDLINE, Embase, LILACS, and the Cochrane Central Register of Controlled Trials, trial registers, conference proceedings, review articles, and reference lists of trial publications for all relevant randomised controlled trials (published, unpublished, and ongoing) comparing either standard of care with or without docetaxel or standard of care with or without bisphosphonates for men with high-risk localised or metastatic hormone-sensitive prostate cancer. For each trial, we extracted hazard ratios (HRs) of the effects of docetaxel or bisphosphonates on survival (time from randomisation until death from any cause) and failure-free survival (time from randomisation to biochemical or clinical failure or death from any cause) from published trial reports or presentations or obtained them directly from trial investigators. HRs were combined using the fixed-effect model (Mantel-Haenzsel).

FINDINGS

We identified five eligible randomised controlled trials of docetaxel in men with metastatic (M1) disease. Results from three (CHAARTED, GETUG-15, STAMPEDE) of these trials (2992 [93%] of 3206 men randomised) showed that the addition of docetaxel to standard of care improved survival. The HR of 0·77 (95% CI 0·68-0·87; p<0·0001) translates to an absolute improvement in 4-year survival of 9% (95% CI 5-14). Docetaxel in addition to standard of care also improved failure-free survival, with the HR of 0·64 (0·58-0·70; p<0·0001) translating into a reduction in absolute 4-year failure rates of 16% (95% CI 12-19). We identified 11 trials of docetaxel for men with locally advanced disease (M0). Survival results from three (GETUG-12, RTOG 0521, STAMPEDE) of these trials (2121 [53%] of 3978 men) showed no evidence of a benefit from the addition of docetaxel (HR 0·87 [95% CI 0·69-1·09]; p=0·218), whereas failure-free survival data from four (GETUG-12, RTOG 0521, STAMPEDE, TAX 3501) of these trials (2348 [59%] of 3978 men) showed that docetaxel improved failure-free survival (0·70 [0·61-0·81]; p<0·0001), which translates into a reduced absolute 4-year failure rate of 8% (5-10). We identified seven eligible randomised controlled trials of bisphosphonates for men with M1 disease. Survival results from three of these trials (2740 [88%] of 3109 men) showed that addition of bisphosphonates improved survival (0·88 [0·79-0·98]; p=0·025), which translates to 5% (1-8) absolute improvement, but this result was influenced by the positive result of one trial of sodium clodronate, and we found no evidence of a benefit from the addition of zoledronic acid (0·94 [0·83-1·07]; p=0·323), which translates to an absolute improvement in survival of 2% (-3 to 7). Of 17 trials of bisphosphonates for men with M0 disease, survival results from four trials (4079 [66%] of 6220 men) showed no evidence of benefit from the addition of bisphosphonates (1·03 [0·89-1·18]; p=0·724) or zoledronic acid (0·98 [0·82-1·16]; p=0·782). Failure-free survival definitions were too inconsistent for formal meta-analyses for the bisphosphonate trials.

INTERPRETATION

The addition of docetaxel to standard of care should be considered standard care for men with M1 hormone-sensitive prostate cancer who are starting treatment for the first time. More evidence on the effects of docetaxel on survival is needed in the M0 disease setting. No evidence exists to suggest that zoledronic acid improves survival in men with M1 or M0 disease, and any potential benefit is probably small.

FUNDING

Medical Research Council UK.

Taxane Chemotherapy for Hormone-Naïve Prostate Cancer with Its Expanding Role as Breakthrough Strategy

Historically, androgen-deprivation therapy (ADT) was the only primary treatment for metastatic prostate cancer. After prostate cancer develops into castration-resistant prostate cancer (CRPC), there are a few life-prolonging drugs, including taxanes, such as docetaxel and cabazitaxel, as well as novel androgen receptor-targeting agents, such as abiraterone acetate and enzalutamide, which have been proved in clinical trials. However, the prognosis of men with CRPC is still poor. The duration from initiation of ADT to CRPC has not improved in recent decades because no novel therapeutic options have emerged. However, recently, up-front docetaxel chemotherapy has been shown to prolong progression-free as well as overall survival in men with metastatic hormone-naïve prostate cancer. This offers a new way to expand the role of chemotherapy for hormone-naïve prostate cancer. In this review, we summarize the proof-of-concept as well as the current status of taxane chemotherapy for hormone-naïve prostate cancer, focusing on phase 3 clinical trials investigating oncological outcome, and discuss the future direction in this field.

Androgen Deprivation Therapy (ADT) Plus Docetaxel Versus ADT Alone in Metastatic Non castrate Prostate Cancer: Impact of Metastatic Burden and Long-term Survival Analysis of the Randomized Phase 3 GETUG-AFU15 Trial

BACKGROUND

The role of chemotherapy in metastatic non castrate prostate cancer (mNCPC) is debated. Survival benefits of docetaxel (D) added to androgen-deprivation therapy (ADT) were shown in the CHAARTED trial in patients with metastatic high-volume disease (HVD).

OBJECTIVE

To assess the impact of metastatic burden and to update overall survival (OS) data of the GETUG-AFU15 study.

DESIGN, SETTING, AND PARTICIPANTS

Randomized phase 3 trial of ADT plus D versus ADT alone in 385 mNCPC patients; median follow-up of 7 yr.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Primary end point was OS. Secondary end points were biochemical progression-free survival (bPFS) and radiographic progression-free survival (rPFS). Retrospective analysis was by tumor volume.

RESULTS AND LIMITATIONS

After a median follow-up of 83.9 mo, median OS in the overall population was 62.1 mo (95% confidence interval [CI], 49.5-73.7) and 48.6 mo (95% CI, 40.9-60.6) for ADT plus D and ADT arms, respectively (hazard ratio [HR]: 0.88 [95% CI, 0.68-1.14]; p=0.3). Median OS in ADT plus D and ADT arms, respectively, was for HVD patients: 39.8 mo (95% CI, 28.0-53.4) versus 35.1 mo (95% CI, 29.9-43.6) (HR: 0.78 [95% CI, 0.56-1.09]; p=0.14), for low-volume disease (LVD) patients; median was not reached (NR; 95% CI, 69.5-NR) and 83.4 mo (95% CI, 61.8-NR) (HR: 1.02 [95% CI, 0.67-1.55]; p=0.9). For upfront metastatic patients, OS was 52.6 mo (95% CI, 43.3-66.8) and 41.5 mo (95% CI, 36.3-54.5), respectively (HR: 0.93 [95% CI, 0.69-1.25]; p=0.6). The bPFS (HR: 0.73 [95% CI, 0.56-0.94]; p=0.014) and rPFS (HR: 0.75 [95% CI, 0.58-0.97]; p=0.030) were significantly longer in the ADT plus D arm. Limitations included the retrospective analysis of metastatic extent and the lack of statistical power to detect a significant difference in subgroups.

CONCLUSIONS

The post hoc analyses of the GETUG-AFU15 study demonstrated a nonsignificant 20% reduction in the risk of death in the HVD subgroup. Patients with LVD had no survival improvement with early D.

PATIENT SUMMARY

In this study, docetaxel added to castration did not improve survival in patients with metastatic hormone-sensitive prostate cancer, partly due to methodological issues. However, early chemotherapy should be discussed with all patients, given the data of three randomized trials including GETUG-AFU15.

Use of early chemotherapy for hormone-sensitive prostate cancer: time for CHAARTED

CHAARTED was an ECOG-led phase III trial looking at early chemotherapy with the use of docetaxel in addition to androgen deprivation therapy (ADT) versus ADT alone in hormone-sensitive prostate cancer. The positive results of the trial showing marked improvement in overall survival in those who received chemotherapy with ADT have revolutionized the treatment of metastatic castration-sensitive prostate cancer. In addition to overall survival, secondary endpoints such as time to castration resistance, PSA response were also significant for the patients who received early chemotherapy.

Novel roles of androgen receptor, epidermal growth factor receptor, TP53, regulatory RNAs, NF-kappa-B, chromosomal translocations, neutrophil associated gelatinase, and matrix metalloproteinase-9 in prostate cancer and prostate cancer stem cells

Approximately one in six men will be diagnosed with some form of prostate cancer in their lifetime. Over 250,000 men worldwide die annually due to complications from prostate cancer. While advancements in prostate cancer screening and therapies have helped in lowering this statistic, better tests and more effective therapies are still needed. This review will summarize the novel roles of the androgen receptor (AR), epidermal growth factor receptor (EGFR), the EGFRvIII variant, TP53, long-non-coding RNAs (lncRNAs), microRNAs (miRs), NF-kappa-B, chromosomal translocations, neutrophil associated gelatinase, (NGAL), matrix metalloproteinase-9 (MMP-9), the tumor microenvironment and cancer stem cells (CSC) have on the diagnosis, development and treatment of prostate cancer.