Combined androgen blockade with bicalutamide for advanced prostate cancer: long-term follow-up of a phase 3, double-blind, randomized study for survival

UBX-390: A Novel Androgen Receptor Degrader for Therapeutic Intervention in Prostate Cancer

The androgen receptor (AR) is an attractive target for treating prostate cancer, considering its role in the development and progression of localized and metastatic prostate cancer. The high global mortality burden of prostate cancer, despite medical treatments such as androgen deprivation or AR antagonist therapy, highlights the need to explore alternative strategies. One strategy involves the use of heterobifunctional degraders, also known as proteolysis-targeting chimeras, which are novel small-molecule therapeutics that inhibit amplified or mutated targets. Here, the study reports a novel cereblon-based AR degrader, UBX-390, and demonstrates its superior activity over established AR degraders, such as ARV-110 or ARCC-4, in prostate cancer cells under short- and long-term treatment conditions. UBX-390 suppresses chromatin binding and gene expression of AR and demonstrates substantial efficacy in the degradation of AR mutants in patients with treatment-resistant prostate cancer. UBX-390 is presented as an optimized AR degrader with remarkable potential for treating castration-resistant prostate cancer.

PSA doubling time 4.65 months as an optimal cut-off of Japanese nonmetastatic castration-resistant prostate cancer

A multicenter study of nonmetastatic castration-resistant prostate cancer (nmCRPC) was conducted to identify the optimal cut-off value of prostate-specific antigen (PSA) doubling time (PSADT) that correlated with the prognosis in Japanese nmCRPC. Of the 515 patients diagnosed and treated for nmCRPC at 25 participating Japanese Urological Oncology Group centers, 450 patients with complete clinical information were included. The prognostic values of clinical factors were evaluated with respect to prostate specific antigen progression-free (PFS), cancer-specific survival (CSS), and overall survival (OS). The optimal cutoff value of PSADT was identified using survival tree analysis by Python. The Median PSA and PSADT at diagnosis of nmCRPC were 3.3 ng/ml, and 5.2 months, respectively. Patients treated with novel hormonal therapy (NHT) showed significantly longer PFS (HR: hazard ratio 0.38, p < 0.0001) and PFS2 (HR 0.45, p < 0.0001) than those treated with vintage nonsteroidal antiandrogen agent (Vintage). The survival tree identified 4.65 months as the most prognostic PSADT cutoff point. Among the clinical and pathological factors PSADT of < 4.65 months remained an independent prognostic factor for OS (HR 2.96, p = 0.0003) and CSS (HR 3.66, p < 0.0001). Current data represented optimal cut-off of PSADT 4.65 months for a Japanese nmCRPC.

Comparison of oncological outcomes of upfront androgen receptor signaling inhibitors and combined androgen blockade in Japanese patients with metastatic castration-sensitive prostate cancer

In recent years, randomized controlled trials have demonstrated that upfront androgen receptor signaling inhibitors (ARSIs) prolong overall survival (OS) compared with androgen deprivation therapy (ADT) alone or combined androgen blockade (CAB) in patients with metastatic castration-sensitive prostate cancer (mCSPC). However, it remains unclear whether upfront ARSI is superior to CAB in Asian populations, among which the efficacy of ADT/CAB is considered relatively high. In this study, we compared the oncological outcomes of upfront ARSI and CAB in Japanese patients with mCSPC. Patients with mCSPC who underwent systemic therapy between May 2009 and October 2023 were enrolled retrospectively. Propensity score matching (PSM) was performed to compare the castration-resistant prostate cancer-free survival (CRPC-FS), cancer-specific survival (CSS), and OS between patients treated with upfront ARSI (ARSI group) and those treated with CAB (CAB group). In total, 30 and 142 patients were enrolled in the ARSI and CAB groups, respectively. After PSM (25 patients in each group), CRPC-FS was significantly longer in the ARSI group than in the CAB group (median: 36.7 vs. 12.3 months, hazard ratio: 0.44, 95% confidence interval: 0.20-0.97, p = 0.035). No significant differences were observed in CSS or OS between the two groups. In conclusion, when compared to CAB, upfront ARSI might have the potential to extend CRPC-FS among individuals in the Japanese population.

Prognostic outcomes in Japanese patients with metastatic castration-sensitive prostate cancer: Comparative assessments between conventional androgen deprivation therapy (ADT) and ADT with novel androgen receptor signal inhibitor

OBJECTIVE

The objective of this study was to compare the prognostic outcomes between metastatic castration-sensitive prostate cancer (mCSPC) patients receiving conventional androgen deprivation therapy (ADT) and those receiving ADT plus a novel androgen-receptor signaling inhibitor (ARSI) in routine clinical practice in Japan.

METHODS

This was conducted as a retrospective multicenter study including 581 mCSPC patients, consisting of 305 receiving ADT alone or in combination with bicalutamide (group 1) and 276 receiving ADT plus one of the following ARSIs: abiraterone acetate, apalutamide, or enzalutamide (group 2). Prognostic outcomes between these 2 groups were comprehensively compared.

RESULTS

In the entire cohort, prostate-specific antigen-progression-free survival (PSA-PFS) in group 2 was significantly longer than that in group 1, while no significant difference was noted in overall survival (OS) between the two groups. In patients corresponding to the LATITUDE high-risk group, however, both PSA-PFS and OS in group 2 were significantly longer than those in group 1. Of several factors examined, the following were identified as independent predictors of poor PSA-PFS in the entire cohort as well as the LATITUDE high-risk group: high C-reactive protein, high lactate dehydrogenase, high alkaline phosphatase, high Gleason score, and group 1. Furthermore, it was possible to precisely classify both the entire cohort and LATITUDE high-risk group into 3 risk groups regarding PSA-PFS according to the positive numbers of independent factors: positive for ≤1 factor, favorable; 2 factors, intermediate; and ≥3 factors, poor.

CONCLUSION

Combined use of ARSIs with ADT could improve the prognostic outcomes of mCSPC patients, particularly those in the LATITUDE high-risk group, in real-world clinical practice in Japan.

Targeting androgen biosynthesis in prostate cancer: implications on endocrine physiology

PURPOSE OF REVIEW

Targeting specific steroidogenic enzymes is effective in decreasing testosterone synthesis, resulting in significant antitumor effects in prostate cancer. Such treatments result in disruptions of complicated and intertwining pathways with systemic physiologic consequences via effects on the adrenal gland and renin-angiotensin-aldosterone axis. This review highlights some of these aspects that need to be taken into consideration when treating patients with androgen biosynthesis inhibitors.

RECENT FINDINGS

Targeting CYP17A1, a key enzyme involved in androgen biosynthesis, is a well established treatment in prostate cancer. More recently, efforts are underway to target a gatekeeper enzyme of steroidogenesis, CYP11A1. This enzyme mediates conversion of cholesterol to pregnenolone, the first step in steroid hormone biogenesis. Studies are beginning to demonstrate antitumor effects of ODM-208, a CYP11A1 inhibitor in prostate cancer. Although anticipated to have a therapeutic role in prostate cancer, there are potential downstream effects of CYP11A1 targeting arising from suppression of the entire adrenal cortex, including long-term adrenal insufficiency and possibly cardiovascular dysregulation.

SUMMARY

Agents targeting androgen biosynthesis can have systemic implications. Balancing management of prostate cancer with better understanding of the mechanisms associated with potential side effects will allow for patients to obtain improved antitumor benefit while mitigating against treatment-associated adverse effects.

GnRH antagonist monotherapy versus a GnRH agonist plus bicalutamide for advanced hormone-sensitive prostate cancer; KYUCOG-1401

OBJECTIVES

To compare the effectiveness and safety of gonadotropin-releasing hormone (GnRH) antagonist monotherapy to combined androgen blockade (CAB) with a GnRH agonist and bicalutamide in patients with advanced hormone-sensitive prostate cancer (HSPC).

METHODS

The study was conducted as KYUCOG-1401 trial (UMIN000014243) and enrolled 200 patients who were randomly assigned to either group A (GnRH antagonist monotherapy followed by the addition of bicalutamide) or group B (CAB by a GnRH agonist and bicalutamide). The primary endpoint was PSA progression-free survival. The secondary endpoints were the time to CAB treatment failure, radiographic progression-free survival, overall survival, changes in serum parameters, including PSA, hormones, and bone and lipid metabolic markers, and adverse events.

RESULTS

PSA progression-free survival was significantly longer in group B (hazard ratio [HR], 95% confidence interval [CI]; 1.40, 1.01-1.95, p = 0.041). The time to CAB treatment failure was slightly longer in group A (HR, 95% CI; 0.80, 0.59-1.08, p = 0.146). No significant differences were observed in radiographic progression-free survival or overall survival. The percentage of patients with serum testosterone that did not reach the castration level was higher at 60 weeks (p = 0.046) in group A. No significant differences were noted in the serum levels of bone metabolic or lipid markers between the two groups. An injection site reaction was more frequent in group A.

CONCLUSIONS

The present results support the potential of CAB using a GnRH agonist and bicalutamide as a more effective treatment for advanced HSPC than GnRH antagonist monotherapy.

A multicenter, retrospective observational study investigating baseline characteristics and clinical outcomes in patients with hormone-sensitive prostate cancer treated with primary androgen deprivation therapy

OBJECTIVE

This multicenter, retrospective, observational study investigated baseline characteristics and clinical outcomes in patients with hormone-sensitive prostate cancer who received primary androgen deprivation therapy, using Japan Study Group of Prostate Cancer registry data.

METHODS

Among patients in the Japan Study Group of Prostate Cancer registry, those who initiated primary androgen deprivation therapy and were aged 20 years or older were enrolled in this study. The primary endpoint was time to disease progression, defined as time from primary androgen deprivation therapy initiation to either prostate-specific antigen or clinical progression. Secondary endpoints included prostate-specific antigen progression-free survival, prostate-specific antigen response (90% or greater reduction from baseline) and distribution of second-line treatment.

RESULTS

Of the 2494 patients (goserelin, n = 564; leuprorelin, n = 1148; surgical castration, n = 161; degarelix, n = 621), those who received degarelix had higher prostate-specific antigen levels and Gleason scores and were at a more advanced clinical stage than those receiving goserelin or leuprorelin. The median time to disease progression (identical to the prostate-specific antigen progression-free survival result) was not reached for goserelin and leuprorelin, 52.7 months for surgical castration and 54.0 months for degarelix. Although baseline prostate-specific antigen values in the degarelix cohort were higher than those of the leuprorelin or goserelin cohorts, prostate-specific antigen responses were not different among the three cohorts. Regarding second-line treatment, the largest patient group received degarelix followed by leuprorelin (n = 195).

CONCLUSIONS

This study clarified patient characteristics and long-term effectiveness of primary androgen deprivation therapy in real-world clinical practice. Japanese urologists appear to select appropriate primary androgen deprivation therapy based on patient background and tumour characteristics, with degarelix largely reserved for higher risk patients.

Oral chemotherapeutic agents in metastatic hormone-sensitive prostate cancer: A network meta-analysis of randomized controlled trials

Background

Multiple oral chemotherapeutic agents for metastatic hormone-sensitive prostate cancer (mHSPC) have been developed for conjugated use with conventional androgen deprivation therapy (ADT). Several randomized controlled trials (RCTs) report significant benefits in mHSPC patients. Therefore, we compared overall survival (OS) and progression-free survival (PFS) benefits among considerable mHSPC oral chemotherapeutic agents.

Materials and methods

We investigated mHSPC treatment efficacy through a systematic RCT-trial literature review (PubMed, Embase, Web of Science, the Cochrane Library, and Scopus). Two reviewers independently screened, extracted data, and assessed bias risk in duplicate.

Results

We identified 18 RCTs (n = 13,509). Concerning OS, ADT + abiraterone, ADT + abiraterone + docetaxel, ADT + apalutamide, ADT + bicalutamide, ADT + darolutamide + docetaxel, ADT + enzalutamide, ADT + orteronel, and ADT + rezvilutamide were more effective than the standard of care (SOC). Comparing PFS, most treatments were more effective than SOC, excluding ADT + bicalutamide, nilutamide, flutamide, ADT + bicalutamide + palbociclib, and ADT + nilutamide. ADT + docetaxel with androgen receptor targeted agent (ARTA) triplet therapy was not among the top three treatments determined through ranking analysis.

Conclusions

Novel oral chemotherapeutic agent combination therapies must replace current ADT monotherapy and ADT + docetaxel SOC. Even so, ADT + docetaxel with ARTA triplet therapy still is not the best mHSPC treatment and requires further study.

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.

Clinical characteristics of patients with metastatic castration-resistant prostate cancer after treatment with combined androgen blockade

BACKGROUND

Although the second-generation androgen receptor inhibitors and taxanes have recently been recommended for the initial treatment of metastatic prostate cancer, bicalutamide and flutamide are still used in a large number of cases. Therefore, it is important to elucidate the clinical characteristics of these treated CRPC cases and their sensitivity to the currently used therapeutic agents. We aimed to examine the outcomes of metastatic castration-resistant prostate cancer following combined androgen blockade as initial therapy at our institution.

METHODS

Ninety-four patients who developed metastatic castration-resistant prostate cancer after hormonal treatment with combined nonsteroidal androgen receptor antagonists and continuous androgen deprivation therapy between January 2015 and December 2020 were included. The presence of visceral metastases, duration of efficacy of each treatment, and overall survival after castration-resistant prostate cancer were evaluated.

RESULTS

Patients with a longer duration of castration-resistant prostate cancer tended to have a longer response duration to subsequent enzalutamide administration (p = 0.003). Patients who achieved a 90% reduction in prostate-specific antigen levels with enzalutamide had a significantly better castration-resistant prostate cancer prognosis (p = 0.002). Meanwhile, those with visceral metastases at the time of castration-resistant prostate cancer diagnosis had a significantly poorer prognosis (p < 0.001). A positive correlation was observed between the treatment efficacy of abiraterone and taxanes for castration-resistant prostate cancer.

CONCLUSION

The study provides scientific evidence to support that patients with longer time to castration-resistant prostate cancer are more sensitive to enzalutamide, and the use of abiraterone between docetaxel and cabazitaxel has favorable prognostic impact. These findings provide instrumental evidence that can enable better treatment selection for prostate cancer patients.

PTEN loss is not a determinant of time to castration-resistance following androgen-deprivation therapy in prostate cancer: a study from Jordan

Androgen deprivation therapy (ADT) remains the principal treatment of advanced prostate cancer. However, most patients eventually experience treatment failure, resulting in castrate-resistant prostate cancer (CRPC). Loss of the tumor suppressor gene phosphatase and tensin homolog (PTEN) has been linked to poor survival in prostate cancer. We have recently shown that PTEN loss is evident in approximately 60% of prostate cancer cases in Jordan. However, the correlation between PTEN loss and response to ADT remains unclear. This study aimed to determine the relationship between PTEN loss and time to CRPC in Jordan. We conducted a retrospective analysis of confirmed CRPC cases at our institution from 2005 to 2019 (N=104). PTEN expression was assessed using immunohistochemistry. Time to CRPC was calculated from the initiation of ADT to the confirmed diagnosis of CRPC. Combination/sequential ADT was defined as the use of two or more classes of ADT concomitantly or switching from one class to another. We found that PTEN loss was evident in 60.6% of CRPC. Mean time to CRPC was not different between patients with PTEN loss (24.8 months) and those with intact PTEN (24.2 months; p=0.9). However, patients receiving combination/sequential ADT had a significantly delayed onset of CRPC compared to patients on monotherapy ADT (log-rank Mantel-Cox p=0.000). In conclusion, PTEN loss is not a major determinant of time to CRPC in Jordan. The use of combination/sequential ADT procures a significant therapeutic advantage over monotherapy regimens, delaying the onset of CRPC.

Comparison of doublet and triplet therapies for metastatic hormone-sensitive prostate cancer: A systematic review and network meta-analysis

Background

The best choice of first-line treatment for metastatic hormone-sensitive prostate cancer (mHSPC) is unclear. We aimed to compare the effectiveness and safety determined in randomized clinical trials of doublet and triplet treatments for mHSPC.

Methods

Medline, Embase, Cochrane Central and ClinicalTrials.gov were searched from inception through July 01, 2022. Eligible studies were phase III randomized clinical trials evaluating androgen deprivation treatment (ADT) alone, doublet therapies [ADT combined with docetaxel (DOC), novel hormonal agents (NHAs), or radiotherapy (RT)], or triplet therapies (NHA+DOC+ADT) as first-line treatments for mHSPC. Outcomes of interest included overall survival (OS), progression-free survival (PFS) and grades 3-5 adverse events (AEs). Subgroup analyses were performed based on tumor burden. The effects of competing treatments were assessed by Bayesian network meta-analysis using R software.

Results

Ten trials with 12,298 patients comparing nine treatments were included. Darolutamide (DARO) +DOC+ADT ranked best in terms of OS benefits (OR 0·52 [95% CI 0·39-0·70]), but its advantages were all statistically insignificant compared with other therapy options except for DOC+ADT (OR 0·68 [95% CI 0·53-0·88]) and RT+ADT (OR 0·57 [95% CI 0·40-0·80]). In terms of PFS, enzalutamide(ENZA)+DOC+ADT (OR 0·32 [95% CI 0·24-0·44]) and abiraterone and prednisone (AAP) +DOC+ADT (OR 0·33 [95% CI 0·25-0·45]) ranked best. For patients with high volume disease (HVD), low volume disease (LVD), and visceral metastases, the optimal therapies were AAP+DOC+ADT (OR 0·52 [95% CI 0·33-0·83]), apalutamide+ADT (OR 0·52 [95% CI 0·26-1·05]) and DARO+DOC+ADT (OR 0·42 [95% CI 0·13-1·34]), respectively. For safety, AAP+DOC+ADT (OR 3·56 [95% CI 1·51-8·43]) ranked worst with the highest risk of grade 3-5 AEs.

Conclusions

Triple therapies may further improve OS and PFS but may be associated with a decrease in safety. Triplet therapies could be suggested for HVD patients, while doublet combinations should still be preferred for LVD patients.

Systematic Review Registration

https://www.crd.york.ac.uk/PROSPEROFILES/303117_STRATEGY_20220202.pdf, identifier CRD4202303117.

Efficacy of abiraterone acetate for high-risk hormone-naïve metastatic prostate cancer: A comparison with combined androgen blockade therapy with bicalutamide and androgen deprivation therapy alone

BACKGROUND

The treatment landscape for men with metastatic hormone-naïve prostate cancer (mHNPC) has dramatically changed with the approval of next-generation anti-androgen drugs. We compared the treatment efficacy of abiraterone with that of combined androgen blockade (CAB) therapy and androgen deprivation therapy (ADT) alone in men with high-risk mHNPC.

METHODS

In total, 146 Japanese men with high-risk mHNPC were retrospectively analyzed. As initial hormonal therapy, 30, 83, and 33 men were treated with ADT plus abiraterone (ABI group), ADT plus bicalutamide (CAB group), and ADT alone (ADT group), respectively. Treatment efficacy was compared using time to castration resistance (TTCR) and prostate-specific antigen (PSA) response among the groups. Propensity score matching analysis was also performed to adjust for baseline differences.

RESULTS

The median (95% confidence interval [CI]) TTCR in the ABI, CAB, and ADT groups were not reached, 10.7 (7.6-13.8) months and 11.0 (7.9-12.4) months, respectively, and it was significantly longer in the ABI group than in the other groups (p = 0.0012, p = 0.0008). In propensity score matching analysis, the median TTCR was also significantly longer in the ABI group than in the other groups (hazard ratio [HR], 0.47; 95% CI, 0.22-0.98; p = 0.010; HR, 0.32; 95% CI, 0.12-0.85; p = 0.004). The number of men who achieved PSA levels ≤0.2 ng/mL after propensity score matching were significantly higher in the ABI group than in the other groups.

CONCLUSIONS

Our results provide important evidence regarding the superiority of abiraterone over CAB therapy and ADT alone for initial treatment for men with newly diagnosed mHNPC.

Health-related quality of life with enzalutamide versus flutamide in castration-resistant prostate cancer from the AFTERCAB study

Background

Patient-reported outcome (PRO) measures can provide valuable information in evaluating patients’ health-related quality of life (HRQoL). Post hoc analysis of the AFTERCAB study was conducted to evaluate the HRQoL benefit of enzalutamide plus androgen deprivation therapy (ADT) compared to flutamide plus ADT for the treatment of patients with castration-resistant prostate cancer (CRPC) in Japan.

Methods

The open-label AFTERCAB study was conducted from November 2016 to March 2020 in Japanese men aged ≥ 20 years with asymptomatic or mildly symptomatic CRPC. Patients received enzalutamide plus ADT or flutamide plus ADT, respectively, as first-line alternative androgen therapy (AAT). HRQoL was analyzed through the Functional Assessment of Cancer Therapy–Prostate, EuroQoL 5-Dimension 5-Level instruments, Brief Pain Inventory–Short Form, and Brief Fatigue Inventory. The longitudinal changes in HRQoL, HRQoL deterioration based on minimally important difference (MID), and time to HRQoL deterioration were evaluated for first-line AAT.

Results

Overall, HRQoL between the enzalutamide and flutamide groups was similar during first-line treatment. No statistically significant HRQoL difference in change from baseline to week 61 (least square mean difference; p value) was observed. Furthermore, proportions of pain progression, symptom worsening, and HRQoL deterioration based on MID, were not significantly different between groups.

Conclusions

The results were similar in all subscales of each PRO, demonstrating similar HRQoL deterioration based on MID criteria between the enzalutamide and flutamide groups.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10147-022-02221-w.

Androgen receptor axis‑targeted agents are not superior to conventional hormonal therapy for treatment of metastatic prostate cancer

The present study aimed to use real-world Japanese data to compare the treatment outcome of conventional hormonal therapy to that of using androgen receptor axis-targeted (ARAT) agents for patients with metastatic castration-resistant prostate cancer. The overall survival between the conventional hormonal therapy group and the ARAT agent therapy group was compared using a group of 75 Japanese patients who were treated for metastatic castration-resistant prostate cancer. A subgroup analysis was carried out and the risk factors that affected overall survival (OS) were determined. The median OS from the time of prostate-specific antigen recurrence was 73.1 months in the ARAT group and 45.2 months in the conventional treatment group (P=0.414). Although OS tended to be slightly longer in the ARAT group, the difference between the groups was not significant. Subgroup analysis suggested that the therapeutic outcome of using ARAT agents tended to be less beneficial in patients who were older, and in those with a higher tumor volume or low Gleason grade. In conclusion, use of ARAT agents did not impart a significant survival benefit to patients with metastatic castration-resistant prostate cancer when compared with survival rates in response to conventional therapy. However, there was some clinical benefit when ARAT agents were used after patients developed castration-resistant prostate cancer. These findings suggest that up-front therapy using ARAT agents at the time of the initial hormone therapy can impart clinical benefit in Japanese patients with metastatic prostate cancer.

Targeting signaling pathways in prostate cancer: mechanisms and clinical trials

Prostate cancer (PCa) affects millions of men globally. Due to advances in understanding genomic landscapes and biological functions, the treatment of PCa continues to improve. Recently, various new classes of agents, which include next-generation androgen receptor (AR) signaling inhibitors (abiraterone, enzalutamide, apalutamide, and darolutamide), bone-targeting agents (radium-223 chloride, zoledronic acid), and poly(ADP-ribose) polymerase (PARP) inhibitors (olaparib, rucaparib, and talazoparib) have been developed to treat PCa. Agents targeting other signaling pathways, including cyclin-dependent kinase (CDK)4/6, Ak strain transforming (AKT), wingless-type protein (WNT), and epigenetic marks, have successively entered clinical trials. Furthermore, prostate-specific membrane antigen (PSMA) targeting agents such as ¹⁷⁷Lu-PSMA-617 are promising theranostics that could improve both diagnostic accuracy and therapeutic efficacy. Advanced clinical studies with immune checkpoint inhibitors (ICIs) have shown limited benefits in PCa, whereas subgroups of PCa with mismatch repair (MMR) or CDK12 inactivation may benefit from ICIs treatment. In this review, we summarized the targeted agents of PCa in clinical trials and their underlying mechanisms, and further discussed their limitations and future directions.

Cell Line Characteristics Predict Subsequent Resistance to Androgen Receptor-Targeted Agents (ARTA) in Preclinical Models of Prostate Cancer

Treatment of prostate cancer (PCa) has changed considerably in the last decade due to the introduction of novel androgen receptor (AR)-targeted agents (ARTAs) for patients progressing on androgen deprivation therapy (ADT). Preclinical research however still relies heavily on AR-negative cell line models. In order to investigate potential differences in castration-resistant PCa (CRPC) growth, we set out to create a comprehensive panel of ARTA-progressive models from 4 androgen-responsive AR wild-type PCa cell lines and analyzed its androgen response as opposed to its ADT-progressive counterparts. Parallel cultures of VCaP, DuCaP, PC346C, and LAPC4 were established in their respective culture media with steroid-stripped fetal calf serum (FCS) [dextran-coated charcoal-stripped FCS (DCC)] without androgen (ADT) or in DCC plus 1 μM of the ARTAs bicalutamide, OH-flutamide, or RD162 (an enzalutamide/apalutamide analog). Cell growth was monitored and compared to those of parental cell lines. Short-term androgen response was measured using cell proliferation 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. qRT-PCR was performed to assess the mRNA expression of markers for AR signaling, steroidogenesis, glucocorticoid receptor (GR) signaling, epithelial-mesenchymal transition (EMT), and WNT signaling. Out of 35 parallel cultures per cell line, a total of 24, 15, 34, and 16 CRPC sublines emerged for VCaP, DuCaP, PC346C, and LAPC4, respectively. The addition of bicalutamide or OH-flutamide significantly increased CRPC growth compared to ADT or RD162. VCaP, DuCaP, and PC346C CRPC clones retained an AR-responsive phenotype. The expression of AR and subsequent androgen response were completely lost in all LAPC4 CRPC lines. Markers for EMT and WNT signaling were found to be elevated in the resilient PC346C model and CRPC derivatives of VCaP, DuCaP, and LAPC4. Although the resistant phenotype is pluriform between models, it seems consistent within models, regardless of type of ARTA. These data suggest that the progression to and the phenotype of the CRPC state might already be determined early in carcinogenesis.

Complete androgen blockade vs. medical castration alone as adjuvant androgen deprivation therapy for prostate cancer patients following radical prostatectomy: a retrospective cohort study

Background:

Till date, the optimal treatment strategy for delivering adjuvant androgen deprivation therapy (ADT) in localized and locally advanced prostate cancer (PCa), as a lower stage in PCa progression compared with metastatic PCa, is still unclear. This study compares the efficacy of castration alone with complete androgen blockade (CAB) as adjuvant ADT in patients with localized and locally advanced PCa undergoing radical prostatectomy (RP).

Methods:

Patients diagnosed with PCa, without lymph node or distant metastasis, who received RP in West China Hospital between January 2009 and April 2019, were enrolled in this study. We performed survival, multivariable Cox proportional hazard regression, and subgroup analyses.

Results:

A total of 262 patients were enrolled, including 107 patients who received castration alone and 155 patients who received CAB. The survival analysis revealed that there was no significant difference between the two groups (hazard ratios [HR] = 1.07, 95% confidence intervals [95% CI] = 0.60–1.90, P = 0.8195). Moreover, the multivariable Cox model provided similarly negative results before and after adjustment for potential covariant. Similarly, there was no significant difference in the clinical recurrence between the two groups in both non-adjusted and adjusted models. Furthermore, our subgroup analysis showed that CAB achieved better biochemical recurrence (BCR) outcomes than medical castration alone as adjuvant ADT for locally advanced PCa (P for interaction = 0.0247, HR = 0.37, 95% CI = 0.14–1.00, P = 0.0497).

Conclusion:

Combined androgen blockade achieved better BCR outcomes compared with medical castration alone as adjuvant ADT for locally advanced PCa without lymph node metastasis.

Real-world survival outcomes of adding docetaxel or abiraterone in patients with high-volume metastatic castration-sensitive prostate cancer: historically controlled, propensity score matched comparison with androgen deprivation therapy

PURPOSE

This study investigated the impact of treatment intensification with upfront docetaxel (DOC) or abiraterone (ABI) plus prednisolone on survival outcomes in patients with metastatic castration-sensitive prostate cancer (mCSPC) by comparing it with androgen deprivation therapy (ADT) monotherapy or combined androgen blockade (CAB) using propensity score matching (PSM).

METHODS

Outcomes from 278 CHAARTED high-volume patients receiving upfront DOC (92 patients) or upfront ABI (186 patients) were compared to those from 354 patients receiving ADT or CAB. PSM was conducted to assess castration-resistant prostate cancer-free survival (CRPCFS) and overall survival (OS).

RESULTS

After PSM, patient distributions between the three groups were well balanced. After 1:1 PSM, patients receiving upfront ABI had significantly better CRPCFS than those receiving ADT/CAB or upfront DOC [hazard ratio (HR) 0.39; 95% CI 0.27-0.56 vs. HR 0.50; 95% CI 0.30-0.82, respectively]. No significant difference in CRPCFS was observed between the upfront DOC and ADT/CAB groups (HR 0.75; 95% CI 0.50-1.12). Patients receiving upfront DOC and upfront ABI had significantly better OS than those receiving ADT/CAB (HR 0.54; 95% CI 0.0.30-0.98 vs. HR 0.49; 95% CI 0.29-0.84, respectively). However, no significant difference in OS was observed between upfront ABI and upfront DOC (hazard ratio 0.84; 95% CI 0.34-2.06).

CONCLUSION

The comparison of real-world retrospective cohorts showed that treatment intensification with upfront DOC or upfront ABI promoted better OS compared to ADT alone or CAB in patients with high-volume mCSPC after PSM. However, no difference in OS was observed between upfront DOC and upfront ABI.

Rational Second-Generation Antiandrogen Use in Prostate Cancer

The second-generation antiandrogens have achieved an ever-growing list of approvals and indications in subsets of prostate cancer. Here, we provide an overview of second-generation antiandrogen trials and FDA approvals and outline a rational sequencing approach for the use of these agents as they relate to chemotherapy and other available treatment modalities in advanced prostate cancer. All published phase II-III randomized controlled trials reporting outcomes with the use of second-generation antiandrogens in prostate cancer are included as well as all published trials and retrospective studies of second-generation antiandrogen sequencing and/or combinations. Complete tabular and graphical representation of all available evidence is provided regarding the use and sequencing of second-generation antiandrogens in prostate cancer. In metastatic castration-resistant prostate cancer, evidence suggests prioritization of abiraterone before chemotherapy, chemotherapy after second-generation antiandrogen failure, and postchemotherapy enzalutamide in select patients to maximize agent efficacy and tolerability. We conclude that a rational, optimized sequencing of second-generation antiandrogens with other treatment options is feasible with present data.

Exploring anti-androgen therapies in hormone dependent prostate cancer and new therapeutic routes for castration resistant prostate cancer

Androgen deprivation therapies (ADTs) are important treatments which inhibit androgen-induced prostate cancer (PCa) progression by either preventing androgen biosynthesis (e.g. abiraterone) or by antagonizing androgen receptor (AR) function (e.g. bicalutamide, enzalutamide, darolutamide). A major limitation of current ADTs is they often remain effective for limited durations after which patients commonly progress to a lethal and incurable form of PCa, called castration-resistant prostate cancer (CRPC) where the AR continues to orchestrate pro-oncogenic signalling. Indeed, the increasing numbers of ADT-related treatment-emergent neuroendocrine-like prostate cancers (NePC), which lack AR and are thus insensitive to ADT, represents a major therapeutic challenge. There is therefore an urgent need to better understand the mechanisms of AR action in hormone dependent disease and the progression to CRPC, to enable the development of new approaches to prevent, reverse or delay ADT-resistance. Interestingly the AR regulates distinct transcriptional networks in hormone dependent and CRPC, and this appears to be related to the aberrant function of key AR-epigenetic coregulator enzymes including the lysine demethylase 1 (LSD1/KDM1A). In this review we summarize the current best status of anti-androgen clinical trials, the potential for novel combination therapies and we explore recent advances in the development of novel epigenetic targeted therapies that may be relevant to prevent or reverse disease progression in patients with advanced CRPC.

Abiraterone acetate versus nonsteroidal antiandrogen with androgen deprivation therapy for high-risk metastatic hormone-sensitive prostate cancer

BACKGROUND

Although prostate cancer is a very common form of malignancy in men, the clinical significance of androgen deprivation therapy (ADT) with abiraterone acetate versus the nonsteroidal antiandrogen bicalutamide has not yet been verified in patients with high-risk metastatic hormone-sensitive prostate cancer (mHSPC). The present study was designed to initiate this verification in real-world Japanese clinical practice.

METHODS

We retrospectively analyzed the records of 312 patients with high-risk mHSPC based on LATITUDE criteria and had received ADT with bicalutamide (n = 212) or abiraterone acetate (n = 100) between September 2015 and December 2020. Bicalutamide was given at 80 mg daily and abiraterone was given at 1000 mg daily as four 250-mg tablets plus prednisolone (5-10 mg daily). Overall survival (OS), cancer-specific survival (CSS), and time to castration-resistant prostate cancer (CRPC) were compared. The prognostic factor for time to CRPC was analyzed by Cox proportional hazard model.

RESULTS

Patients in the bicalutamide group were older, and more of them had poor performance status (≧2), than in the abiraterone group. Impaired liver function was noted in 2% of the bicalutamide group and 16% of the abiraterone group (p < 0.001). Median follow-up was 22.5 months for bicalutamide and 17 months for abiraterone (p < 0.001). Two-year OS and CSS for bicalutamide versus abiraterone was 77.8% versus 79.5% (p = 0.793) and 81.1% versus 82.5% (p = 0.698), respectively. Median time to CRPC was significantly longer in the abiraterone group than in the bicalutamide group (NA vs. 13 months, p < 0.001). In multivariate analysis, Gleason score ≧9, high alkaline phosphatase, high lactate dehydrogenase, liver metastasis, and bicalutamide were independent prognostic risk factors for time to CRPC. Abiraterone prolonged the time to CRPC in patients with each of these prognostic factors.

CONCLUSIONS

Despite limitations regarding the time-dependent bias, ADT with abiraterone acetate significantly prolonged the time to CRPC compared to bicalutamide in patients with high-risk mHSPC. However, further study with longer follow-up is needed.

Clinical Effects of Jiawei Danggui Beimu Kushen Pills in the Treatment of Prostate Cancer and Their Influence on the Expression of Serum Prostate Specific Antigen

Objective

To observe the clinical effects of Jiawei Danggui Beimu Kushen pills in treating prostate cancer and their influence on the expression of serum prostate specific antigen.

Methods

A total of 234 prostate cancer patients were selected and randomly divided into observation group and control group, with 117 cases in each group. The control group was given oral bicalutamide tablets, while the observation group was treated with Jiawei Danggui Beimu Kushen pills on the basis of the control group. The treatment efficacy, IPSS score, TCM syndrome score, VAS score, quality-of-life score, and immune function of the two groups were compared before and after treatment. The serum PSA and f-PSA levels of patients before treatment and after 30 days, 90 days, and 180 days of treatment in the two groups were compared. The five-year cumulative survival rate and the incidence of adverse reactions were compared between the two groups.

Results

After treatment, the total effective rate of the observation group was 88.03% (103/117), which was higher than that of the control group 69.23% (81/117); the difference was statistically significant (P < 0.05). After treatment, the IPSS score, TCM syndrome score, and VAS score of the two groups were reduced, and those in the observation group were lower than those in the control group; the difference was statistically significant (P < 0.05). After treatment, the quality-of-life scores of the two groups increased, and the observation group was higher than the control group; the difference was statistically significant (P < 0.05). Before treatment, there was no significant difference in serum PSA levels and f-PSA levels when comparing between the two groups of patients (P > 0.05). With the increase of treatment time, the two index levels of the two groups were gradually decreased. After 180 days of treatment, the two index levels of the two groups of patients were significantly lower than those before treatment, and the two index levels of the observation group were significantly lower than those of the control group; the difference was statistically significant (P < 0.05). After treatment, the levels of IgM and IgA in the two groups were decreased, and the level of IgG was increased. The difference between the two groups in the levels of each index before and after treatment was statistically significant (P < 0.05), and the difference between the two groups in the levels of each index after treatment was also statistically significant (P < 0.05). The five-year cumulative survival rate of the observation group was 69.23%, and the five-year cumulative survival rate of the control group was 46.15% (P < 0.05). There was no statistically significant difference between the two groups in the incidence of dizziness, fatigue, and gastrointestinal reactions (P > 0.05), but the difference in the incidence of dysuria as well as dysuria and hematuria was statistically significant (P < 0.05).

Conclusion

Jiawei Danggui Beimu Kushen pills are effective in treating prostate cancer, which can effectively reduce the patients' IPSS score and TCM syndrome scores, relieve the pain, and improve the quality of life of patients. They also have a potential role in regulating serum PSA levels, clearing tumor lesions, reducing postoperative complications, and improving related symptoms.

A New Old Target: Androgen Receptor Signaling and Advanced Prostate Cancer

Owing to the development of multiple novel therapies, there has been major progress in the treatment of advanced prostate cancer over the last two decades; however, the disease remains invariably fatal. Androgens and the androgen receptor (AR) play a critical role in prostate carcinogenesis, and targeting the AR signaling axis with abiraterone, enzalutamide, darolutamide, and apalutamide has improved outcomes for men with this lethal disease. Targeting the AR and elucidating mechanisms of resistance to these agents remains central to drug development efforts. This review provides an overview of the evolution and current approaches for targeting the AR in advanced prostate cancer. It describes the biology of AR signaling, explores AR-targeting resistance mechanisms, and discusses future perspectives and promising novel therapeutic strategies. Expected final online publication date for the Annual Review of Pharmacology and Toxicology, Volume 62 is January 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Multidisciplinary Therapy in Men with Newly Diagnosed Oligometastatic Prostate Cancer

Purpose

To assess the use of aggressive local therapy with systemic therapy for patients with oligometastatic prostate cancer.

Patients and Methods

Patients with oligometastatic prostate cancer received systemic therapy centered on androgen deprivation therapy (ADT). After six months or more of ADT, the patients received radiation therapy or surgery for the prostate, and radiation therapy for all metastatic sites. ADT was continued for 2–3 years after local therapy.

Results

Twelve patients who were judged to be able to undergo radiotherapy or surgical treatment of the prostate and radiation therapy for all metastatic sites and one case of pubic bone recurrence after radical prostatectomy were included. Bone metastases (n = 11) and para-aortic lymph node metastases (n = 2) were found. The number of bone metastases was one (n = 7), two (n = 3), and three (n = 1). Radiation therapy (70–74 Gy) was performed on the prostate in 11 of 12 patients. A prostatectomy was performed on one patient who was judged to be unable to receive a sufficient dose to the metastatic site when radical radiation was applied to the prostate. Radiation therapy (45–60 Gy) was performed on all metastatic sites. Prostate-specific antigen (PSA) levels increased again during treatment in three patients. There was a significant difference in PSA levels before local therapies between the three patients who developed castration-resistant prostate cancer (CRPC) during the course of treatment and the eight patients who did not progress to CRPC (p = 0.012). There was also a significant difference in PSA levels after local therapies between the three patients who developed CRPC during the course of treatment and the eight patients who did not progress to CRPC (p = 0.012). Four patients completed treatment. In one patient in whom the testosterone level recovered to the normal level the PSA level remained the level below the measurement sensitivity.

Conclusion

Aggressive local therapy in combination with systemic therapy centered on ADT is a promising treatment option for oligometastatic prostate cancer.

Enzalutamide + androgen deprivation therapy (ADT) versus flutamide + ADT in Japanese men with castration‐resistant prostate cancer: AFTERCAB study

Objectives

The objective of the study is to compare the efficacy and safety of alternative androgen therapy (AAT) with enzalutamide + androgen deprivation therapy (ADT) and flutamide + ADT in the treatment of Japanese men with metastatic or nonmetastatic castration‐resistant prostate cancer (CRPC) who progressed despite combined androgen blockade (CAB) with bicalutamide + ADT. AAT treatment sequence was also investigated.

Materials and methods

The open‐label, Phase 4 AFTERCAB study (NCT02918968) was conducted from November 2016 to March 2020 in Japanese men aged ≥20 years with asymptomatic or mildly symptomatic CRPC. Patients were initially randomized to enzalutamide (160 mg/day) + ADT (enzalutamide first) or flutamide (375mg/day [125mg three times daily]) + ADT (flutamide first) as first‐line therapy. Following prostate‐specific antigen (PSA) progression, other disease progression, or discontinuation of first‐line therapy due to an adverse event (AE), patients switched to the other treatment as second‐line therapy. The primary endpoint was time to PSA progression with first‐line therapy (TTPP1). Secondary endpoints included TTPP2 (TTPP1 + time to PSA progression with second‐line therapy). AEs were monitored to assess safety.

Results

Overall, 206 men were randomized (enzalutamide first, n = 102; flutamide first, n = 104) and stratified by study site and disease stage; 133 patients transitioned to second‐line therapy (enzalutamide first, n = 48; flutamide first, n = 85). TTPP1 was significantly improved with enzalutamide first versus flutamide first (median 21.4 months vs. 5.8 months; hazard ratio [HR] 0.42; 95% confidence interval [CI] [0.29, 0.61]). TTPP2 was numerically improved with enzalutamide first versus flutamide first (median not reached vs. 21.2 months; HR 0.76; 95% CI [0.48, 1.19]). Both treatments were generally well tolerated, with AEs consistent with their known safety profiles.

Conclusion

First‐line AAT with enzalutamide + ADT provided a significant improvement in time to PSA progression versus flutamide + ADT. Enzalutamide + ADT may therefore be the preferred first‐line AAT option in Japanese men with metastatic or nonmetastatic CRPC who progress despite CAB with bicalutamide + ADT.

Abiraterone acetate versus bicalutamide in combination with gonadotropin releasing hormone antagonist therapy for high risk metastatic hormone sensitive prostate cancer

The objective of this study was to compare the efficacy of abiraterone acetate with that of bicalutamide in combination with gonadotropin-releasing hormone (GnRH) antagonist treatment for patients with high-risk metastatic hormone-sensitive prostate cancer (mHSPC). A total of 149 patients with mHSPC who underwent treatment at our hospital and affiliated hospitals between December 2013 and July 2020 were retrospectively identified. Fifty patients were administered abiraterone acetate (1000 mg/day) plus prednisolone (5 mg/day) with a GnRH antagonist (degarelix) (group A), and 99 patients were administered bicalutamide (80 mg/day) with a GnRH antagonist (group B). The prostate-specific antigen (PSA) progression-free survival (PSA-PFS) was significantly longer in group A than in group B. Abiraterone acetate therapy and Gleason score were significant independent factors of PSA-PFS. Using propensity score matching, 56 matched patients were obtained. The PSA-PFS (p < 0.001) and overall survival (OS) (p = 0.0071) of patients with high-risk mHSPC were significantly longer in group A of matched patients. Abiraterone acetate therapy and Gleason score were significant independent factors for PSA-PFS in matched patients. The PSA-PFS and OS of patients treated with abiraterone acetate in combination with a GnRH antagonist were significantly better than those treated with bicalutamide.

Which Way to Choose for the Treatment of Metastatic Prostate Cancer: A Case Report and Literature Review

Background

Prostate cancer (PCa) is the second most common cancer among males in the world and the majority of patients will eventually progress to the metastatic phase. How to choose an effective way for the treatment of metastatic PCa, especially in the later stage of the disease is still confusing. Herein we reported the case of a patient diagnosed with metastatic PCa and conducted a literature review on this issue.

Case Presentation

A 57-year-old man with metastatic PCa had been managed by Dr. J.P. since April 2012 when the patient was admitted to the Third Affiliated Hospital of Sun Yat-sen University by aggravating frequent urination and dysuria. The prostate-specific antigen (PSA) concentration was 140 ng/ml, and the diagnosis of PCa was confirmed by prostate biopsy, with Gleason score 4 + 5 = 9. Chest CT and bone scan indicated multiple metastases in the lungs and bones. Triptorelin, bicalutamide, zoledronic acid, and docetaxel were then administered, six cycles later, the metastatic tumors in the lungs disappeared and those in the bones lessened significantly, along with a remarkable reduction in PSA level (< 2 ng/ml). Intermittent androgen deprivation was subsequently conducted until August 2018, when the serum PSA level was found to be 250 ng/ml, again docetaxel 75 mg/m² was administered immediately but the patient was intolerant this time. Instead, abiraterone was administered until March 2019 because of intolerable gastrointestinal side-effects and increasing PSA level. In October 2019, the patient came to our center, a modified approach of docetaxel (day 1 40 mg/m² + day 8 35 mg/m²) was administered. Luckily, the PSA level decreased rapidly, the bone pain was greatly relieved, and no obvious side effects occurred. However, four cycles later, docetaxel failed to work anymore, the metastatic tumor in the liver progressed. We proposed several regimens as alternatives, but they were soon denied due to the high prices or unavailability or uncertain effect of the drugs. In addition, the patient’s condition deteriorated speedily and can no longer bear any aggressive treatment. Finally, the patient died of multiple organ failure in August 2020.

Conclusion

The experiences of this case provide valuable evidence and reference for the treatment choices of metastatic PCa, in some circumstances modified and advanced regimens may produce unexpected effects.

Initial Management of Noncastrate Advanced, Recurrent, or Metastatic Prostate Cancer: ASCO Guideline Update

PURPOSE

Update all preceding ASCO guidelines on initial hormonal management of noncastrate advanced, recurrent, or metastatic prostate cancer.

METHODS

The Expert Panel based recommendations on a systematic literature review. Recommendations were approved by the Expert Panel and the ASCO Clinical Practice Guidelines Committee.

RESULTS

Four clinical practice guidelines, one clinical practice guidelines endorsement, 19 systematic reviews with or without meta-analyses, 47 phase III randomized controlled trials, nine cohort studies, and two review papers informed the guideline update.

RECOMMENDATIONS

Docetaxel, abiraterone, enzalutamide, or apalutamide, each when administered with androgen deprivation therapy (ADT), represent four separate standards of care for noncastrate metastatic prostate cancer. Currently, the use of any of these agents in any particular combination or series cannot be recommended. ADT plus docetaxel, abiraterone, enzalutamide, or apalutamide should be offered to men with metastatic noncastrate prostate cancer, including those who received prior therapies, but have not yet progressed. The combination of ADT plus abiraterone and prednisolone should be considered for men with noncastrate locally advanced nonmetastatic prostate cancer who have undergone radiotherapy, rather than castration monotherapy. Immediate ADT may be offered to men who initially present with noncastrate locally advanced nonmetastatic disease who have not undergone previous local treatment and are unwilling or unable to undergo radiotherapy. Intermittent ADT may be offered to men with high-risk biochemically recurrent nonmetastatic prostate cancer. Active surveillance may be offered to men with low-risk biochemically recurrent nonmetastatic prostate cancer. The panel does not support use of either micronized abiraterone acetate or the 250 mg dose of abiraterone with a low-fat breakfast in the noncastrate setting at this time.Additional information is available at www.asco.org/genitourinary-cancer-guidelines.

Endocrine consequences of treatment with the new androgen receptor axis-targeted agents for advanced prostate cancer

PURPOSE

Prostate cancer (PCa) is the commonest non-cutaneous malignancy worldwide and the second cause of cancer death among males in the USA. Approval of the new androgen receptor axis-targeted (ARAT) agents (abiraterone acetate, enzalutamide, apalutamide, and darolutamide) has altered the course of advanced PCa. We aimed to assess the endocrine and metabolic adverse events associated with treatment using ARAT compounds.

METHODS

We searched the PubMed, Cochrane Library, and Scopus databases from database inception to August 2020. We included randomized controlled trials reporting the endocrine and metabolic side effects of ARAT agents compared to each other or to placebo.

RESULTS

Although metastatic PCa remains incurable, ARAT medications combined with androgen deprivation therapy improve overall metastasis-free and progression-free survival in metastatic hormone-sensitive PCa, non-metastatic castration-resistant PCa, and metastatic castration-resistant PCa patients. This benefit comes at the cost of certain endocrine and metabolic consequences. Treatment with abiraterone acetate induces mineralocorticoid excess, hypokalemia, hypertension, elevated liver function tests, insulin resistance, and hyperglycemia. Enzalutamide may induce or worsen hypertension and increase the risk of falls and fractures in elderly patients, while common endocrine adverse events of apalutamide include hypothyroidism, hypertension, and skin rash. On the other hand, darolutamide seems to have a somewhat safer endocrine and metabolic profile.

CONCLUSION

Treatment of advanced PCa should be personalized, with administration of a combination of androgen deprivation therapy, ARAT agents, and chemotherapy being based on the patient's safety profile and the risk of side effects.

Long Non-Coding RNA Landscape in Prostate Cancer Molecular Subtypes: A Feature Selection Approach

Prostate cancer is one of the most common malignancies in men. It is characterized by a high molecular genomic heterogeneity and, thus, molecular subtypes, that, to date, have not been used in clinical practice. In the present paper, we aimed to better stratify prostate cancer patients through the selection of robust long non-coding RNAs. To fulfill the purpose of the study, a bioinformatic approach focused on feature selection applied to a TCGA dataset was used. In such a way, LINC00668 and long non-coding(lnc)-SAYSD1-1, able to discriminate ERG/not-ERG subtypes, were demonstrated to be positive prognostic biomarkers in ERG-positive patients. Furthermore, we performed a comparison between mutated prostate cancer, identified as "classified", and a group of patients with no peculiar genomic alteration, named "not-classified". Moreover, LINC00920 lncRNA overexpression has been linked to a better outcome of the hormone regimen. Through the feature selection approach, it was found that the overexpression of lnc-ZMAT3-3 is related to low-grade patients, and three lncRNAs: lnc-SNX10-87, lnc-AP1S2-2, and ADPGK-AS1 showed, through a co-expression analysis, significant correlation values with potentially druggable pathways. In conclusion, the data mining of publicly available data and robust bioinformatic analyses are able to explore the unknown biology of malignancies.

[ADVERSE EFFECTS OF ANDROGEN DEPRIVATION THERAPY ON PATIENTS WITH PROSTATE CANCER AND ITS EFFECT ON OVERALL SURVIVAL]

(Background) Patients with prostate cancer, which progresses slowly compared with other cancers, are generally older, and not a few are solely treated with androgen-deprivation therapy (ADT). The physical effects of ADT on bone health, body composition, and hematological parameters must be carefully considered. (Methods) We collected the clinical records of 185 men with pathologically diagnosed prostate cancer who were treated with ADT at our hospital. The primary aim of the study was to determine the prevalence and severity of adverse effects caused by ADT. The second aim was to analyze the effect of fluctuation in the rate of these adverse effects on overall survival (OS). (Results) The median age of patients was 75 years. After ADT for 1 or 2 years, evaluation of bone mineral density revealed median losses of 3% and 6%, respectively. After ADT for 1 year, body mass index was significantly increased by a median 2.1%, and total cholesterol and hemoglobin levels were significantly increased and decreased, respectively. The local and systemic symptoms of subcutaneous granuloma and hot flashes were experienced by 39% and 21.6% patients, respectively. Mono- and multivariate analysis revealed that significant fluctuation in the rate of adverse events after 1-year ADT did not affect OS. (Conclusion) Prevalence and severity of adverse effects caused by ADT were acceptable and almost all patients could be treated in the outpatient clinic, and significant fluctuation in the rate of adverse effects had no effect on OS.

[EFFECT OF NEW ANDROGEN RECEPTOR AXIS-TARGETED AGENTS ON SURVIVAL OF CASTRATION-RESISTANT PROSTATE CANCER]

(Background)The real world's effect of new androgen receptor axis-targeted agents (ARATs) on survival of castration-resistant prostate cancer (CRPC) remains unclear in Japan. (Aims)The primary aim was to determine the clinical benefit of ARATs on survival of CRPC patients. The secondary aim was to evaluate predictive factors affecting the survival of CRPC patients. (Patients and results)Among 236 patients treated with androgen deprivation therapy (ADT), 68 patients developed CRPC; two groups of 34 patients were treated with ARATs (A cases) or conventional ADT (V cases). In a median follow-up of 61.5 months, 20 A and 22 V cases died of cancer. Median survival time (MST) from diagnosis was 99 and 66 months for A and V cases, respectively, and MST from CRPC to death were 50.5 and 44.5 months, respectively. There were no significant differences between both cases. The hazard ratio for death from diagnosis or CRPC progression of the A cases to V cases was 0.711; 95% confidence interval (CI), 0.371 to 1.362; P = 0.3037, or 0.805; 95% CI, 0.434 to 1.491; P=0.4899, respectively. Multivariable analysis revealed that a unique and significant independent prognostic factor from diagnosis was time to CRPC. (Conclusions)In this small retrospective study, we could not determine the clinical benefit of new ARATs compared with conventional ADT on survival of CRPC patients, and a unique and significant independent prognostic factor from diagnosis was time to CRPC. We need to validate these results in a future multi-institutional study.

Systemic therapy in the management of recurrent or metastatic salivary duct carcinoma: A systematic review

BACKGROUND

Salivary duct carcinoma (SDC) is an aggressive subtype of salivary gland cancer. Approximately half of SDC patients will develop recurrences or metastases. Therapeutic palliative therapy is therefore often needed. The majority of SDC tumors expresses the androgen receptor (AR) and one-third expresses human epidermal growth factor receptor 2 (HER2), both are potential therapeutic targets. The aim of this paper is to systematically review and summarize the evidence on systemic palliative therapy for SDC and to provide treatment recommendations.

MATERIALS AND METHODS

Electronic libraries were systematically searched with a broad search strategy to identify studies where SDC patients received systemic therapy. Due to the rarity of SDC no restrictions were placed on study designs.

RESULTS

The search resulted in 2014 articles of which 153 were full-text analyzed. Forty-five studies were included in the analysis, which included in total 256 SDC patients receiving systemic therapy. Two phase 2 trials primarily including SDC patients were identified. The majority of the studies were case series or case reports, resulting in an overall low quality of available evidence. Based on studies including ≥ 5 SDC patients, objective responses to HER2 targeting agents were observed in 60-70%, to AR pathway agents in 18-53% and to chemotherapy in 10-50%.

CONCLUSION

For AR or HER2 positive SDC, agents targeting these pathways are the cornerstone for palliative treatment. Regarding chemotherapy, the combination of carboplatin combined with a taxane is best studied. Regarding other targeted agents and immunotherapy evidence is anecdotal, limiting formulation of treatment recommendations for these antineoplastic agents.

[Combination therapy for metastatic hormone-sensitive prostate cancer: What? When? For whom?]

Novel combination therapies are currently the standard systemic treatment for metastatic hormone-sensitive prostate cancer. As a result, the overall survival of patients can be extended by approximately 1.5 years. The taxane docetaxel, the CYP17 inhibitor abiraterone and the second generation antiandrogen apalutamide can currently be used as a combination partner for classic androgen deprivation. While the de novo synthesis of testosterone is the rationale for abiraterone or apalutamide combination, taxanes offer a promising approach in the presence of primarily androgen-independent prostate cancer cells. Due to the increased rate of side effects caused by combination therapy, it is important to clarify in daily clinical practice which patient group benefits in particular from the respective combination therapy. Hereby, the metastatic pattern, general condition and age play an important role. While there is good evidence of the use of docetaxel or abiraterone in visceral metastasis, apalutamide offers a very wide range of uses. Ultimately, the recommendation for combination therapy is always an individual decision that needs to be discussed with the patient, considering the benefits and risks.

Hormonal prostate cancer therapies and cardiovascular disease: a systematic review

Therapeutic intervention for prostate cancer mostly relies on eliminating circulating androgen or antagonizing its effect at the cellular level. As the use of endocrine therapies grows, an under-reported incidence of cardiovascular toxicities occurs in prostate cancer patients. In this review, we summarize data of clinical studies, investigating the cardiovascular and metabolic alterations associated with the use of old and new endocrine drugs (gonadotropin-releasing hormone [GnRH] agonists and antagonists, androgen receptor inhibitors, 17α-hydroxylase/c-17,20-lyase [CYP17] inhibitor) in prostate cancer. To date, studies looking for links between cardiovascular complications and hormone-mediated therapies in prostate cancer have reached conflicting results. Several confounding factors, such as age of patients and related cardiovascular liability, other comorbidities, and use of concomitant drugs, have to be carefully evaluated in future clinical trials. Further research is needed given the continuous advancements being made in prostate cancer treatment.

The management of patients with metastatic prostate cancer during the COVID-19 pandemic

During the ongoing global pandemic of coronavirus disease 2019 (COVID-19), the benefit of treating patients with cancer must be weighed against the COVID-19 infection risks to patients, staff and society. Prostate cancer is one of the most common cancers among men and raises particular interest during the pandemic as recent reports show that the TMPRSS2 (and other serine proteases), which facilitate the entry, replication and budding of the virion from a cell, can be inhibited using androgen deprivation therapy. Nevertheless, patients with metastatic prostate cancer commonly receive chemotherapy which may compromise their immune system. This paper aims to address the current status of the COVID-19 in patients with cancer overall and suggests an optimal approach to patients with metastatic prostate cancer.

Efficacy and Safety of Non-Steroidal Anti-Androgens in Patients with Metastatic Prostate Cancer: Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Prostate cancer (PCa) is the sixth primary cause of cancer death. However, conflicts are present about the efficacy and safety of Non-steroidal anti-androgens (NSAA) for its treatment. The aim of this study was to assess the efficacy and safety of NSAAs versus any comparator for the treatment of advanced or metastatic PCa (mPCa).

METHODS

MEDLINE and the Cochrane Library were searched. References of included studies and clinicaltrials.gov were also searched for relevant studies. Only English language studies after 1990 were considered for review. Randomized controlled trials (RCTs) examining the efficacy and safety of NSAAs as compared with any other comparator including surgery or chemotherapy in mPCa patients were included. The outcomes include efficacy, safety and the tolerability of the treatment. The Cochrane Risk of Bias Assessment Tool was used for quality assessment. Two authors were independently involved in the selection, extraction and quality assessment of included studies and disagreements were resolved by discussion or by consulting a third reviewer.

RESULTS

Fifty-eight out of 1307 non-duplicate RCTs with 29154 patients were considered for the review. NSAA showed significantly better progression-free survival [PFS] (Hazard ratio [HR], 0.60; 95% confidence interval [CI], 0.46-0.78; P=0.0001), time to distant metastasis or death [TTD] (HR, 0.80; 95% CI 0.73-0.91; P<0.0001), objective response (Odds ratio [OR], 1.64; 95% CI 1.06-2.54; P=0.03) and clinical benefits (OR, 1.33; 95% CI 1.08-1.63; P=0.006) as compared to the control group. There was no significant difference observed between the groups in terms of overall survival (HR, 0.95; 95%CI, 0.87-1.03; P=0.18) and time to progression (HR, 0.93; 95% CI 0.77-1.11; P=0.43). Treatment-related adverse events were more with the NSAA group, but the discontinuation due to lack of efficacy reason was 43% significantly lesser than the control group in patients with mPCa. Rest of the outcomes were appeared to be non-significant.

CONCLUSION

Treatment with NSAA was appeared to be better efficacious with respect to PFS, TTD, and response rate with considerable adverse events when compared to the control group in patients with metastatic PCa.

[LOCAL REACTIONS OF LUTEINIZING HORMONE-RELEASING HORMONE AGENTS AND ITS EFFECTS ON CLINICAL OUTCOMES IN PROSTATE CANCER PATIENTS]

(Background) Currently, luteinizing hormone-releasing hormone (LH-RH) agonists and antagonists are used for androgen-deprivation therapy (ADT). However, they are associated with subcutaneous granuloma, rubor, dolor, calor, and eventual ulcer and/or abscess formation. The prevalence of these adverse effects, causes and mechanisms, and effects on serum testosterone levels and clinical outcomes are poorly understood. (Method) We collected the clinical records of men with pathologically diagnosed prostate cancer who were followed in our hospital. The primary aim of the study was to determine the prevalence of granuloma formation, its causes, and the mechanisms involved. The secondary aim was to analyze the effects of subcutaneous induration on serum testosterone levels and clinical outcomes. (Results) Overall, 185 men using leuprorelin (n=161; median age, 75 years), degarelix (n=21; median age, 76), or goserelin (n=3; median age, 76) were analyzed. In the leuprorelin cohort, 51 patients (33.5%) had subjective and/or objective subcutaneous induration and 2 (1.2%) had a large lesion (diameter > 3.0 cm). In the degarelix cohort, 18 patients (85.7%) developed induration and 8 (38%) had a large lesion. One month after the start of ADT, patients in the leuprorelin and degarelix cohorts had median serum testosterone levels that reached the same level as that after castration. There was no significant difference in the overall survival rate between the leuprorelin and degarelix cohorts. There was no significant difference in the serum testosterone level or overall survival rate between patients with or without induration. (Conclusions) The local adverse effects of LH-RH agents are prevalent, but we can regulate the adverse effects by understanding the mechanism involved. The formation of subcutaneous induration did not affect the serum testosterone level or clinical outcome.

Androgen Receptor in Breast Cancer: From Bench to Bedside

Breast cancer (BC) is one of the most common malignancies and the leading cause of cancer-related mortality in women. Androgen receptor (AR) is frequently expressed in diverse BC subtypes. Accumulating evidence has revealed that AR might be a predictive or prognostic factor and a drug target in BC. AR expression and AR pathways differ in various BC subtypes, thereby resulting in controversial inferences on the predictive and prognostic value of AR. Herein, we summarized the roles of AR in different BC subtypes and AR-targeting therapies based on preclinical and clinical studies. Moreover, we highlighted the possible efficacy of a combination therapy via exploiting the AR-related mechanisms and the research on therapeutic resistance.

Predictors of poor response to first-generation anti-androgens as criteria for alternate treatments for patients with non-metastatic castration-resistant prostate cancer

PURPOSE

There are no criteria for administering first- or second-generation anti-androgens (FGA and SGA, respectively) to patients with non-metastatic castration-resistant prostate cancer (nmCRPC). This study aimed to assess the efficacy of alternative FGA therapy in nmCRPC patients and the prognosis of these patients and to identify factors for predicting patients potentially responsive to FGA.

METHODS

Data from 63 men with nmCRPC who underwent alternative FGA therapy (bicalutamide, flutamide, or chlormadinone acetate) as first-line therapy after failure of primary androgen-deprivation therapy (PADT) between 2004 and 2017 at Hiroshima University Hospital and affiliated hospitals were retrospectively investigated. The associations of clinicopathological parameters with overall survival (OS) and prostate-specific antigen (PSA) progression-free survival (PFS) of alternative FGA-treated patients were analyzed.

RESULTS

Time to CRPC [p = 0.007, hazard ratio (HR) = 4.77], regional lymph node involvement at the diagnosis of CRPC (p = 0.022, HR = 2.42), and PSA-PFS of alternative FGA therapy ≤ 6 months (p = 0.020, HR = 2.39) were identified as prognostic factors using a multivariate analysis. Additionally, Cox proportional hazard models revealed that PSA nadir value > 1 ng/mL during PADT (p = 0.034, HR = 2.40) and time from starting PADT to PSA nadir ≤ 1 year (p = 0.047, HR = 1.85) were predictive factors for worse PSA-PFS in alternative FGA therapy.

CONCLUSIONS

Shorter time to CRPC, regional lymph node involvement, PSA nadir during PADT > 1 ng/mL, and time from starting PADT to PSA nadir ≤ 1 year might suggest the potential benefit of immediate commencement of SGA, compared to FGA administration after nmCRPC diagnosis.

Comparative clinical effects and cost-effectiveness of maximum androgen blockade, docetaxel with androgen deprivation therapy and ADT alone for the treatment of mHSPC in China

Aim: To compare the clinical effects and cost-effectiveness of maximum androgen blockade (MAB), docetaxel to androgen deprivation therapy (Doc-ADT) and ADT alone for the treatment of patients with metastatic hormone-sensitive prostate cancer in China. Methods: A network meta-analysis and a Markov model were adopted for effectiveness and economic evaluation. Results: The hazard ratios of overall survival and progression-free survival were 0.782 and 0.628 for Doc-ADT versus ADT alone; 0.897 and 0.824 for MAB versus ADT alone. Doc-ADT was cost-effective compared with MAB and ADT alone, with an incremental cost-effectiveness ratio of CNY 96,848 and CNY 67,758 per quality-adjusted life year, respectively. MAB was cost-effective compared with ADT alone, with an incremental cost-effectiveness ratio of CNY 137,487 per quality-adjusted life year. Conclusion: Doc-ADT is likely the optimal option from the perspective of both clinical outcomes and economic considerations.

Treatment patterns of prostate cancer with bone metastasis in Beijing: A real-world study using data from an administrative claims database

Purpose

To explore treatment patterns among patients with prostate cancer and bone metastasis and to compare clinical outcomes following use of different hormone therapies including combined androgen blockade (CAB), nonsteroidal antiandrogen (NSAA) monotherapy, and castration monotherapy.

Methods

We conducted a population‐based cohort study using data from the Urban Employee Basic Medical Insurance database (2011‐2014) in Beijing. We identified 475 patients with newly diagnosed bone metastatic prostate cancer with at least one prescription for hormone therapy and described their treatment patterns over a median follow‐up of 20.7 months. Cox proportional hazards model was used to compare time to chemotherapy initiation between patients starting on different hormone therapies.

Results

Hormone therapy and/or bisphosphonate therapy with zoledronic acid were the initial treatments in the majority of patients (87.8%); chemotherapy, radiotherapy, and surgery were usually given later in the treatment pathway. CAB was the most common hormone treatment (73.7%). For time to chemotherapy initiation, hazard ratios (95% confidence intervals) were 2.43 (1.08‐5.44) for NSAA alone vs CAB and 1.29 (0.78‐2.13) for castration alone vs CAB.

Conclusions

Our findings show that while a wide range of therapies are used to treat patients with prostate cancer and bone metastasis in Beijing, hormone therapy and bisphosphonate therapy are the most commonly prescribed, and use of CAB was seen to be advantageous in delaying time to chemotherapy initiation over NSAA monotherapy. Future studies should explore longer‐term treatment patterns, including use of newly approved treatments.

Combined androgen blockade (CAB) versus luteinizing hormone-releasing hormone (LHRH) agonist monotherapy for androgen deprivation therapy

PURPOSE

Combined androgen blockade (CAB) and luteinizing hormone-releasing hormone (LHRH) agonist monotherapy are commonly used in androgen deprivation therapy (ADT). In this randomized clinical trial, we aimed to compare the two methods of ADT in terms of quality of life (QOL).

METHODS

Eighty patients who underwent primary ADT for newly diagnosed prostate cancer were randomly assigned to CAB group (Group 1) and LHRH agonist monotherapy group (Group 2). Leuprolide and anti-androgen (bicalutamide 50 mg) were used to minimize the confounding effects caused by medication. QOL was evaluated at baseline, 3 months and 6 months post-ADT using validated EORTC QLQ-C30, PR25, and depression questionnaires. A difference of > 10 points in the EORTC domain scores was defined as 'clinically significant'.

RESULTS

In the baseline characteristics, there was no significant difference between the two groups. At 3 months after ADT, Group 1 had significantly lower pain scores than Group 2 (p = 0.004), while Group 1 had significantly poorer diarrhea symptom score than Group 2, without clinical significance (p = 0.047). No significant differences were observed in the C30, PR25 domains, and the depression score at 3 months. At 6 months, the QOL scores of all the groups were similar.

CONCLUSIONS

There was no difference in the patient's QOL, except that CAB group was associated with significantly better pain relief than LHRH agonist monotherapy at 3 months following ADT, which was not sustained thereafter. Our results suggest that the benefit of prolonged (≥ 3 months) CAB is questionable in terms of patients' QOL.

Enzalutamide versus flutamide for castration-resistant prostate cancer after combined androgen blockade therapy with bicalutamide: study protocol for a multicenter randomized phase II trial (the OCUU-CRPC study)

Background

Enzalutamide is an oral androgen receptor targeted agent that has been shown to improve survival in PREVAIL trials and has been approved for patients with chemo-naïve metastatic castration-resistant prostate cancer (CRPC). Meanwhile, flutamide is a non-steroidal oral anti-androgen that was commonly used before the approval of bicalutamide. The objective of the OCUU-CRPC study is to compare the efficacy and safety between second-line hormonal therapy of enzalutamide and flutamide as alternative anti-androgen therapy (AAT) after combined androgen blockade (CAB) therapy that included bicalutamide in patients with CRPC.

Methods

A total of 100 patients with CRPC with or without distant metastases after disease progression who received CAB therapy with bicalutamide were randomly assigned at a 1:1 ratio according to distant metastases to the enzalutamide (160 mg/day, 4 × 40 mg capsules once daily) and flutamide (375 mg/day; 3 × 125 mg tablets thrice daily) groups. The primary endpoint for the drug efficacy is the response rate of prostate-specific antigen (PSA) (i.e., the ratio of patients whose PSA declined by ≥50% from baseline) at 3 months. Meanwhile, the secondary endpoints are PSA progression rate at 3 and 6 months, PSA response rate at 6 months, change in quality of life, PSA progression-free survival, and safety. The patient registration started in January 2015 and will end in March 2018, and the follow-up period is 6 months after the last patient registration. The main result will be reported in March 2019.

Discussion

In the OCUU-CRPC study, we compare the efficacy and safety of enzalutamide or alternative AAT with flutamide in participants with CRPC who were previously treated with a CAB therapy with bicalutamide. The expected results of this study will be that enzalutamide is superior to flutamide in terms of PSA response. A longer time to disease progression with enzalutamide over flutamide may translate to better overall survival. However, flutamide may be more accessible for patients owing to its lower cost than enzalutamide.

Trial registration

The OCUU-CRPC study was prospectively registered at clinicaltrials.gov (NCT02346578, January 2015) and University Hospital Medical Information Network (UMIN000016301, January 2015).