Enzalutamide and Survival in Nonmetastatic, Castration-Resistant Prostate Cancer

Clinical implications of the Drug-Drug Interaction in Cancer Patients treated with innovative oncological treatments

In the last two-decades, innovative drugs have revolutionized cancer treatments, demonstrating a significant improvement in overall survival. These drugs may present several pharmacokinetics interactions with non-oncological drugs, and vice versa, and, non-oncological drugs can modify oncological treatment outcome both with pharmacokinetic interaction and with an "off-target impact" on the tumor microenvironment or on the peripheral immune response. It's supposed that the presence of a drug-drug interaction (DDI) is associated with an increased risk of reduced anti-tumor effects or severe toxicities. However, clinical evidence that correlate the DDI presence with outcome are few, and results are difficult to compare because of difference in data collection and heterogeneous population. This review reports all the clinical evidence about DDI to provide an easy-to-use guide for DDI management and dose adjustment in solid tumors treated with inhibitors of the cyclin-dependent kinases CDK4-6, Antibody-drug conjugates, Poly ADPribose polymerase inhibitors, androgen-receptor targeted agents, or immunecheckpoints inhibitors.

Efficacy and safety of androgen receptor inhibitors for treatment of advanced prostate cancer: A systematic review and network meta-analysis

AIMS

Androgen receptor inhibitors (ARIs) have become an effective treatment for advanced prostate cancer (PC). However, it is unknown which ARI is the most helpful and safe for men with advanced PC. Our aim is to help physicians make clinical decisions and provide medication guidelines for patients with advanced PC to avoid potential risks when using ARIs for treatment.

METHODS

We systematically searched the following databases: PubMed, Embase and Cochrane Library, with a literature publication deadline of February 2023. The primary efficacy outcomes were 18-month overall survival (OS), treatment-emergent adverse events (TEAEs), hypertension and fatigue. The network meta-analysis (NMA) was performed by Stata 15.1, and Revman 5.3 was used to assess the included studies' risk of bias.

RESULTS

The analysis included 26 trials with 26 263 people. The surface under the cumulative ranking curve (SUCRA) concluded that enzalutamide (86.8%) showed the best effect in prolonging the OS of patients. Flutamide led to the highest risk of TEAEs (29.9%) and AEs leading to discontinuation (12.8%). Apalutamide (13.4%) led to the highest risk of grade ≥3 TEAEs. Enzalutamide had the highest risk of hypertension (0.2%), grade ≥3 hypertension (4.5%) and fatigue (5.2%).

CONCLUSIONS

This NMA indicates there is no one ARI to reach both the most effective and safe therapy aims for treating advanced PC and that there is a compromise between the efficacy and safety of ARIs in the treatment of advanced PC. Physicians should weigh the risks to safety against the anticipated benefits when prescribing these drugs to patients with PC.

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.

Prostate-Specific Membrane Antigen PET Response Associates with Metastasis-Free Survival After Stereotactic Ablative Radiation in Oligometastatic Prostate Cancer

Purpose

Emerging data suggest that metastasis-directed therapy (MDT) improves outcomes in patients with oligometastatic castration-sensitive prostate cancer (omCSPC). Prostate-specific membrane antigen positron emission tomography (PSMA-PET) can detect occult metastatic disease, and PSMA response has been proposed as a biomarker for treatment response. Herein, we identify and validate a PSMA-PET biomarker for metastasis-free survival (MFS) following MDT in omCSPC.

Methods and Materials

We performed an international multi-institutional retrospective study of patients with omCSPC, defined as ≤3 lesions, treated with metastasis-directed stereotactic ablative radiation who underwent PSMA-PET/computed tomography (CT) before and after (median, 6.2 months; range, 2.4-10.9 months) treatment. Pre- and post-MDT PSMA-PET/CT maximum standardized uptake value (SUVmax) was measured for all lesions, and PSMA response was defined as the percent change in SUVmax of the least responsive lesion. PSMA response was both evaluated as a continuous variable and dichotomized into PSMA responders, with a complete/partial response (at least a 30% reduction in SUVmax), and PSMA nonresponders, with stable/progressive disease (less than a 30% reduction in SUVmax). PSMA response was correlated with conventional imaging-defined metastasis-free survival (MFS) via Kaplan-Meier and Cox regression analysis.

Results

A total of 131 patients with 261 treated metastases were included in the analysis, with a median follow-up of 29 months (IQR, 18.5-41.3 months). After stereotactic ablative radiation, 70.2% of patients were classified as PSMA responders. Multivariable analysis demonstrated that PSMA response as a continuous variable was associated with a significantly worse MFS (hazard ratio = 1.003; 95% CI, 1.001-1.006; P = .016). Patients classified as PSMA responders were found to have a significantly improved median MFS of 39.9 versus 12 months (P = .001) compared with PSMA nonresponders. Our study is limited as it is a retrospective review of a heterogenous population.

Conclusions

After stereotactic ablative radiation, PSMA-PET response appears to be a radiographic biomarker that correlates with MFS in omCSPC. This approach holds promise for guiding clinical management of omCSPC and should be validated in a prospective setting.

Cardiovascular Events and Androgen Receptor Signaling Inhibitors in Advanced Prostate Cancer: A Systematic Review and Meta-Analysis

Importance

Cardiovascular (CV) events remain a substantial cause of mortality among men with advanced and metastatic prostate cancer (PCa). The introduction of novel androgen receptor signaling inhibitors (ARSI) has transformed the treatment landscape of PCa in recent years; however, their associated CV toxic effects remains unclear.

Objective

To assess the incidence of CV events with addition of ARSI to standard of care (SOC) in locally advanced (M0) and metastatic (M1) PCa.

Data Sources

Systematic searches of PubMed, Scopus, Web of Science, EMBASE, and ClinicalTrials.gov were performed from inception up to May 2023.

Study Selection

Randomized clinical trials of ARSI agents (abiraterone, apalutamide, darolutamide, enzalutamide) that reported CV events among individuals with M0 and M1, hormone-sensitive prostate cancer (HSPC) and castration-resistant prostate cancer (CRPC).

Data Extraction and Synthesis

A systematic review was performed in accordance with PRISMA guidance. Two authors screened and independently evaluated studies eligible for inclusion. Data extraction and bias assessment was subsequently performed.

Main Outcomes and Measures

A random-effects meta-analysis was performed to estimate risk ratios for the incidence of all grade and grade 3 or higher CV events (primary outcomes), in addition to hypertension, acute coronary syndrome (ACS), cardiac dysrhythmia, CV death, cerebrovascular event, and venous thromboembolism (secondary outcomes). Sources of heterogeneity were explored using meta-regression.

Results

There were 24 studies (n = 22 166 patients; median age range, 63-77 years; median follow-up time range, 3.9-96 months) eligible for inclusion. ARSI therapy was associated with increased risk of all grade CV event (risk ratio [RR], 1.75; 95% CI, 1.50-2.04; P < .001) and grade 3 or higher CV events (RR, 2.10; 95%, 1.72-2.55; P < .001). ARSI therapy also was associated with increased risk for grade 3 or higher events for hypertension (RR, 2.25; 95% CI, 1.74-2.90; P < .001), ACS (RR, 1.93; 95% CI, 1.43-1.60; P < .01), cardiac dysrhythmia (RR, 1.64; 95% CI, 1.23-2.17; P < .001), cerebrovascular events (RR, 1.86; 95% CI, 1.34-2.59; P < .001) and for CV-related death (RR, 2.02; 95% CI, 1.32-3.10; P = .001). Subgroup analysis demonstrated increased risk of all CV events across the disease spectrum (M0 HSPC: RR, 2.26; 95% CI, 1.36-3.75; P = .002; M1 HSPC: RR, 1.85; 95% CI, 1.47-2.31; P < .001; M0 CRPC: RR, 1.79; 95% CI, 1.13-2.81; P = .01; M1 CRPC: RR, 1.46; 95% CI, 1.16-1.83; P = .001).

Conclusions and Relevance

This systematic review and meta-analysis found that the addition of ARSIs to traditional ADT was associated with increased risk of CV events across the prostate cancer disease spectrum. These results suggest that patients with prostate cancer should be advised about and monitored for the potential of increased risk of CV events with initiation of ARSI therapy alongside conventional hormonal therapy.

Weekly ultra-hypofractionated radiotherapy in localised prostate cancer

Background

Moderately hypofractionated radiotherapy regimens or stereotactic body radiotherapy (SBRT) are standard of care for localised prostate cancer. However, some patients are unable or unwilling to travel daily to the radiotherapy department and do not have access to, or are not candidates for, SBRT. For many years, The Royal Marsden Hospital NHS Foundation Trust has offered a weekly ultra-hypofractionated radiotherapy regimen to the prostate (36 Gy in 6 weekly fractions) to patients unable/unwilling to travel daily.

Methods

The current study is a retrospective analysis of all patients with non-metastatic localised prostate cancer receiving this treatment schedule from 2010 to 2015.

Results

A total of 140 patients were included in the analysis, of whom 86 % presented with high risk disease, with 31 % having Gleason Grade Group 4 or 5 disease and 48 % T3 disease or higher. All patients received hormone treatment, and there was often a long interval between start of hormone treatment and start of radiotherapy (median of 11 months), with 34 % of all patients having progressed to non-metastatic castrate-resistant disease prior to start of radiotherapy. Median follow-up was 52 months. Median progression-free survival (PFS) and overall survival (OS) for the whole group was 70 months and 72 months, respectively. PFS and OS in patients with hormone-sensitive disease at time of radiotherapy was not reached and 75 months, respectively; and in patients with castrate-resistant disease at time of radiotherapy it was 20 months and 61 months, respectively.

Conclusion

Our data shows that a weekly ultra-hypofractionated radiotherapy regimen for prostate cancer could be an option in those patients for whom daily treatment or SBRT is not an option.

Plexin D1 emerges as a novel target in the development of neural lineage plasticity in treatment-resistant prostate cancer

Treatment-induced neuroendocrine prostate cancer (t-NEPC) often arises from adenocarcinoma via lineage plasticity in response to androgen receptor signaling inhibitors, such as enzalutamide. However, the specific regulators and targets involved in the transition to NEPC are not well understood. Plexin D1 (PLXND1) is a cellular receptor of the semaphorin (SEMA) family that plays important roles in modulating the cytoskeleton and cell adhesion. Here, we found that PLXND1 was highly expressed and positively correlated with neuroendocrine markers in patients with NEPC. High PLXND1 expression was associated with poorer prognosis in prostate cancer patients. Additionally, PLXND1 was upregulated and negatively regulated by androgen receptor signaling in enzalutamide-resistant cells. Knockdown or knockout of PLXND1 inhibited neural lineage pathways, thereby suppressing NEPC cell proliferation, patient derived xenograft (PDX) tumor organoid viability, and xenograft tumor growth. Mechanistically, the heat shock protein 70 (HSP70) regulated PLXND1 protein stability through degradation, and inhibition of HSP70 decreased PLXND1 expression and NEPC organoid growth. In summary, our findings indicate that PLXND1 could serve as a promising therapeutic target and molecular marker for NEPC.

Docetaxel versus androgen receptor signaling inhibitor (ARSI) against chemo-naïve castration-resistant prostate cancer (CRPC): propensity score matched analysis in real world

PURPOSE

Although docetaxel and ARSI are picked up as treatment options against chemo-naïve metastatic CRPC in clinical guidelines for prostate cancer, there is no clear evidence which agent should be introduced as first line treatment. Therefore, we investigated our CRPC cohort treated with docetaxel or ARSI as first-line agent against chemo-naïve CRPC to solve these clinical questions.

PATIENTS AND METHODS

A total of 345 chemotherapy-naïve CRPC patients introduced to first-line docetaxel or ARSI (abiraterone or enzalutamide) between March 2006 and April 2017 at Jikei University Hospital and its affiliated institutions were included in this study. Propensity score matching method was used to minimize the patients' background. The outcome measures were PSA response rate, PSA decline ≥ 90%, cancer specific survival (CSS) and overall survival (OS).

RESULTS

PSA decline correlated OS and CSS (p = 0.027, < 0.001, respectively) and median PSA decline rate was 60.4% in docetaxel group and 85.7% in ARSI group (p = 0.0311). Median OS was 33 m (95%CI: 27-53) in docetaxel group and 61 m (95%CI: 47-NA) in ARSI group (p = 0.0246). Median CSS was 34 m (95%CI: 27-53) in docetaxel group and NR (not reached) (95%CI: 61-NA) in ARSI group (p = 0.000133) in propensity score matching cohort. In multivariate analysis, ARSI induction first showed significantly better for OS and CSS (p = 0.0033 and < 0.001, respectively).

CONCLUSION

In this study, better survival outcome with ARSI induction first than docetaxel against chemo-naïve CRPC. And the candidates who had survival benefit by induction docetaxel first could not be found in this study.

The current landscape of stereotactic body radiation therapy for metastatic castration-resistant prostate cancer

BACKGROUND

The onset of castration-resistance is associated with dismal outcomes in patients with prostate cancer (PCa). Metastasis directed therapy has been investigated in multiple disease settings and may improve outcomes in selected patients. Our systematic review aims to summarize evidence with stereotactic body radiotherapy (SBRT) in castration-resistant prostate cancer (CRPC).

METHODS

The literature search was performed on March 2024, on Pubmed, using the keywords "SBRT" AND "CRPC", and "stereotactic ablative radiotherapy (SABR)" AND "CRPC". This search retrieved a total of 108 articles, 19 were included.

RESULTS

The literature is largely dominated by retrospective series. In men with metachronous oligoprogression, SBRT with androgen receptor pathway inhibitor significantly increased progression-free survival (PFS) including biochemical progression-free survival in a randomized phase II trial (hazard ratio of 0.35, p < 0.001). In patients continuing ADT, the bPFS ranged between 9.5 months to 17.9 months, and next systemic treatment-free survival (NEST-FS) reached up to 2 years. In men with induced oligoprogression, SBRT enabled NEST-FS up to 3 years. SBRT was well tolerated, with less than 5% grade 3 toxicity reported across studies.

CONCLUSION

In the population of patients with oligometastatic CRPC, SBRT enables long-term biochemical response and PFS. In the oligoprogressive setting, SBRT could be integrated to prolong the duration and efficacy of systemic therapies. Nevertheless, the level of evidence remains very low and inclusion within prospective trials remain the preferred option for this population of patients.

Prostate-specific Membrane Antigen Positron Emission Tomography-detected Disease Extent and Overall Survival of Patients with High-risk Nonmetastatic Castration-resistant Prostate Cancer: An International Multicenter Retrospective Study

Previously, we demonstrated that prostate-specific membrane antigen positron emission tomography (PSMA-PET) revealed distant metastases in 109/200 patients (39% distant nodes, 24% bone, and 6% visceral organ) with nonmetastatic castration-resistant prostate cancer (nmCRPC) and high-risk features (International Society of Urological Pathology score ≥4 and/or prostate-specific antigen doubling time ≤10 mo) without metastases by conventional imaging. However, the impact of disease extent determined by PSMA-PET on patient outcomes is unknown. We followed these 200 patients for a median of 43 mo after PSMA-PET and retrospectively assessed the association between patient characteristics, PSMA-PET findings, treatment management, and outcomes using a Kaplan-Meier model and Cox multivariable regressions. Among assessed disease characteristics, polymetastatic disease (five or more distant lesions on PET) was independently associated with shorter overall survival (OS; median 61 mo vs not reached; hazard ratio [95% confidence interval], 1.81 [1.00-3.27]; p = 0.050) and time to new metastases (median 38 vs 60 mo; 1.80 [1.10-2.96]; p = 0.019), and initial pN1 status with shorter OS (55 mo vs not reached; 1.94 [1.12-3.37]; p = 0.019). Following PSMA-PET, locoregional salvage therapies were used most commonly in no/local disease (58%), and androgen receptor signaling inhibitors were used in distant metastatic disease (51%). PSMA-PET provides additional risk stratification for patients with nmCRPC. Polymetastatic disease (five or more distant lesions) is associated with worse outcomes. PATIENT SUMMARY: A novel sensitive imaging technology, called prostate-specific membrane antigen positron emission tomography (PSMA-PET), allows doctors to detect the spread of prostate cancer, known as distant metastases, earlier and more accurately than in the past. In our study, PSMA-PET detected none to many metastases in patients who were considered free of distant metastasis by conventional imaging. These findings predicted outcomes and were used to select appropriate treatment.

Cardiovascular Toxicity Associated With Androgen Receptor Axis-Targeted Agents in Patients With Prostate Cancer: A Meta-analysis of Randomized Controlled Trials

INTRODUCTION

Second-generation androgen receptor axis-targeting (ARAT) agents have become a standard treatment for patients with advanced prostate cancer (PC), however much remains unknown about the potential cardiovascular toxicities.

PATIENTS AND METHODS

We performed a systematic search of PubMed, Embase, Web of Science, and Cochrane library for randomized controlled trials of patients receiving ARAT agents for PC from inception to March 2023. The odds ratios (ORs) of all-grade and high-grade cardiovascular adverse events (CVAEs) for patients treated with and without ARAT agents were pooled for meta-analysis. Subgroup analyses based on PC type and treatment regimen were conducted.

RESULTS

A total of 15 double-blind placebo-controlled phase 3 trials comprising 15,842 patients were included. In addition to hot flush and hypertension of any degree of severity, inclusion of ARAT agents was associated with a significantly higher risk of acute myocardial infarction (OR: 1.96, 95% CI: 1.05-3.68, P = .04), myocardial infarction (OR: 2.44, 95% CI: 1.27-4.66, P = .007) and angina pectoris (OR: 2.00, 95% CI: 1.00-4.02, P = .05). With regard to individual ARAT agents, enzalutamide was associated with a significantly higher risk of acute myocardial infarction (OR: 3.11, 95% CI: 1.17-8.28, P = .02), coronary artery disease (OR: 8.33, 95% CI: 1.54-44.95, P = .01), and high-grade hypertension (OR: 4.94, 95% CI: 1.11-22.06, P = .04), while abiraterone and apalutamide were associated with a significantly higher risk of angina pectoris (OR: 5.48, 95% CI: 1.23-24.33, P = .03) and myocardial infarction (OR: 7.00, 95% CI: 1.60-30.62, P = .01), respectively.

CONCLUSION

The inclusion of ARAT agents was associated with a significantly higher risk of several CVAEs. Clinicians should remain vigilant, both in pre-treatment screening and monitoring for clinical symptoms and signs, when considering ARAT agent particularly for patients with pre-existing risk factors.

Biochemical recurrence in patients with prostate cancer after primary definitive therapy: treatment based on risk stratification

BACKGROUND

Nearly one-third of patients with prostate cancer (PCa) experience biochemical recurrence (BCR) after primary definitive treatment. BCR increases the risk of distant metastasis and mortality in patients with prognostically unfavorable features. These patients are best managed with a tailored treatment strategy incorporating risk stratification using clinicopathological factors, next-generation imaging, and genomic testing.

OBJECTIVE

This narrative review examines the utility of risk stratification for the management of patients with BCR in the context of clinical trial data, referencing the latest recommendations by European and US medical societies.

METHODS

PubMed was searched for relevant studies published through May 21 2023 on treatment of patients with BCR after radical prostatectomy (RP) or external beam radiotherapy (EBRT).

RESULTS

European and US guidelines support the risk-stratified management of BCR. Post-RP, salvage EBRT (with or without androgen deprivation therapy [ADT]) is an accepted treatment option for patients with BCR. Post-EBRT, local salvage therapies (RP, cryotherapy, high-intensity focused ultrasound, stereotactic body radiotherapy, and low-dose-rate and high-dose-rate brachytherapy) have demonstrated comparable relapse-free survival rates but differing adverse event profiles, short and long term. Local salvage therapies should be used for local-only relapses while ADT should be considered for regional or distant relapses. In practice, patients often receive ADT, with varying guidance for intermittent ADT vs. continuous ADT, due to consideration of quality-of-life effects.

CONCLUSIONS

Despite a lack of consensus for BCR treatment among guideline associations and medical societies, risk stratification of patients is essential for personalized treatment approaches, as it allows for an informed selection of therapeutic strategies and estimation of adverse events. In lower-risk disease, observation is recommended while in higher-risk disease, after failed repeat local therapy, ADT and/or clinical trial enrollment may be appropriate. Results from ongoing clinical studies of patients with BCR should provide consensus for management.

The treatment landscape of nonmetastatic castrate resistant prostate cancer: A contemporary perspective

OBJECTIVES

The incidence of nonmetastatic castrate resistant prostate cancer (nmCRPC) is not well defined in contemporary practice. The aim of this study is to describe the incidence and patterns of treatment of nmCRPC over the last 6 years at a single high-volume Australian health institution.

SUBJECTS AND METHODS

All men newly diagnosed with prostate cancer at Western Health, Melbourne from January 2016 to December 2021 were included in the study. Those diagnosed with nonmetastatic prostate cancer and treated with medical or surgical castration for biochemical failure post attempted curative therapy were retrospectively reviewed for signs of castration resistance using prostate specific antigen (PSA) and testosterone biochemical markers up until October 2022.

RESULTS

From January 2016 to December 2021, 822 patients were diagnosed with prostate cancer, 590 had localized disease, 373 underwent definitive locoregional therapy, and 31 went on to have biochemical recurrence and were commenced on androgen deprivation therapy. Twenty-five patients had undetectable PSA levels and were classified as having nonmetastatic castrate sensitive prostate cancer (nmCSPC), whilst the remaining 6 patients experienced a rising PSA and were thus classified as nmCRPC. The incidence rate of nmCRPC was 228 cases per 100,000 person-years. The median age at the time of prostate biopsy was 74 years (interquartile range [IQR] 64-79) in the nmCRPC group and 62 years (IQR 57-69) in the nmCSPC group. The median prebiopsy PSA (ng/ml) in the nmCRPC and nmCSPC groups were 27.5 (IQR 19.9-50.4), and 16.5 (IQR 9.0-26.0), respectively. The median duration from prostate cancer diagnosis to onset of nmCRPC was 24 months (IQR 17-29) and the median PSA doubling time was 3.4 months (IQR 2.2-5.7).

CONCLUSIONS

Thus, nmCRPC is an uncommon disease. Further population-based studies are required to better understand the incidence of nmCRPC.

Innovative therapeutic strategies to overcome radioresistance in breast cancer

Despite a comparatively favorable prognosis relative to other malignancies, breast cancer continues to significantly impact women's health globally, partly due to its high incidence rate. A critical factor in treatment failure is radiation resistance - the capacity of tumor cells to withstand high doses of ionizing radiation. Advancements in understanding the cellular and molecular mechanisms underlying radioresistance, coupled with enhanced characterization of radioresistant cell clones, are paving the way for the development of novel treatment modalities that hold potential for future clinical application. In the context of combating radioresistance in breast cancer, potential targets of interest include long non-coding RNAs (lncRNAs), micro RNAs (miRNAs), and their associated signaling pathways, along with other signal transduction routes amenable to pharmacological intervention. Furthermore, technical, and methodological innovations, such as the integration of hyperthermia or nanoparticles with radiotherapy, have the potential to enhance treatment responses in patients with radioresistant breast cancer. This review endeavors to provide a comprehensive survey of the current scientific landscape, focusing on novel therapeutic advancements specifically addressing radioresistant breast cancer.

Practical implications of androgen receptor inhibitors for prostate cancer treatment

Antiandrogens have been used for the treatment of prostate cancer as a single agent or in combination with hormone deprivation therapy. New generation antiandrogens act like androgen receptor inhibitors (ARIs). Their binding complex blocks the pathways of cellular proliferation and differentiation of the prostate. Enzalutamide, apalutamide and darolutamide are the new ARIs that demonstrated acceptable tolerability and toxicity, both active in hormone-sensitive and castration-resistant prostate cancer (CRPC). There is no evidence of superiority of one drug over the other, therefore the therapeutic choice depends on the safety profile in relation to the individual patient, their comorbidities and clinical condition. ARIs have also shown promising results in association with new drugs that are active on patients with metastatic CRPC carrying the mutated breast cancer gene (BRCA). Before undergoing new antiandrogenic therapies, patients should be evaluated for cardiological and metabolic risk and possible drug interactions.

Impact of Comorbidities and Drug Interactions in Patients With Metastatic Castration-Resistant Prostate Cancer Receiving Androgen Receptor Pathway Inhibitors

PURPOSE

Androgen receptor pathway inhibitors (ARPIs) are widely prescribed in metastatic castration-resistant prostate cancer (mCRPC). Real-world frequencies and potential impacts of comorbidities and concomitant medication (conmed) interactions with ARPIs are not well described.

METHODS

Patients receiving ARPIs for mCRPC were identified from the electronic Prostate Cancer Australian Database (ePAD). Demographics, clinicopathologic characteristics, and outcome data were extracted. Conmeds and comorbidities were collected from medical records. Potential interacting comorbidities were defined from trial and post-trial data. Clinically significant drug-drug interactions (DDIs) were identified using UpToDate Lexicomp and Stockley's databases. Patient characteristics, comorbidity interactions, DDIs, and outcomes were analyzed.

RESULTS

Two hundred thirty-five patients received first- or second-line ARPIs for mCRPC from 2012 to 2021, with a median follow-up of 27 months. One hundred sixteen received abiraterone acetate (AAP) and 135 received enzalutamide (ENZ). The median age was 74 years, and the median number of conmeds was 4. Clinically significant DDIs occurred in 55 (47%) AAP patients and 90 (67%) ENZ patients. Only 5% of DDIs were predicted to affect ARPI pharmacokinetics (PK) or pharmacodynamics, whereas 95% were predicted to impact conmed PK or increase toxicity risk. In patients receiving ENZ, DDIs were associated with lower PSA50 (50% v 74%, P = .04) and poorer overall survival (28 v 45 months, P = .04), although statistical significance was not maintained on multivariate analysis. No significant survival differences were seen with DDIs in patients receiving AAP. Potential interactions between comorbidities and ARPI were present in 72% on AAP and 14% on ENZ with no significant associated survival differences.

CONCLUSION

DDIs and drug-comorbidity interactions in real-world patients receiving ARPIs for mCRPC are common and may affect outcomes. Ongoing clinician education regarding DDIs is necessary to optimize patient outcomes.

Effectiveness and safety of enzalutamide and apalutamide in the treatment of patients with non-metastatic castration-resistant prostate cancer (nmCRPC): a multicenter retrospective study

OBJECTIVE

Phase III clinical trials demonstrated the efficacy of enzalutamide and apalutamide in patients with non-metastatic castration-resistant prostate cancer (nmCRPC) and PSA doubling time ≤10 months. Although these drugs have been shown to vary in their adverse event (AE) profiles, the differences in their efficacy profiles remain to be evaluated. Therefore, this retrospective study was conducted to evaluate the efficacy of these drugs in patients with nmCRPC.

METHODS

This study evaluated 191 patients with nmCRPC treated with enzalutamide (n = 137) or apalutamide (n = 54) in the first-line setting at Jikei University Hospital or its affiliated hospitals between May 2014 and November 2022. Endpoints were defined as oncological outcomes (i.e., PSA response, PFS, PSA-PFS, MFS, CSS, and OS) and AEs.

RESULTS

No significant differences were noted in patient backgrounds between the two groups. Patients exhibiting a maximum PSA response of >50% and >90% accounted for 74.5% and 48.9% of patients in the enzalutamide group, and 75.9% and 42.6% of patients in the apalutamide group, respectively, with no significant difference between the groups. The median PSA-PFS was 10 months in the enzalutamide group but not in the apalutamide group, with no significant difference between the groups (P = 0.48). No significant differences were observed in MFS, CSS, or OS between the groups. Patients reporting AEs of all grades and grade 3 or higher accounted for 56.2% and 4.3% of those in the enzalutamide group and 57.4% and 7.4% of those in the apalutamide group, respectively. The most common AE was fatigue (26.3%) in the enzalutamide group and skin rash (27.8%) in the apalutamide group.

CONCLUSION

In this retrospective study of their efficacy and safety, enzalutamide and apalutamide were shown to exhibit comparable oncological outcomes but quite different AE profiles, suggesting that their differential use may be warranted based on these findings.

A Real World Observational Study Characterizing Patients With Advanced Prostate Cancer Treated With or Without Androgen Receptor-Pathway-Inhibitor Therapies in Alberta, Canada

BACKGROUND

Data are needed to improve the current understanding of clinical management and characteristics of patients with advanced prostate cancer (PC) treated with androgen receptor pathway inhibition (ARPI) therapy.

METHODS

This retrospective cohort study using real-world, population-level data from Alberta, Canada included all individuals diagnosed in 2017-2020 with de novo metastatic castration-sensitive PC (mCSPC) or nonmetastatic castration-resistant PC (nmCRPC) who initiated androgen deprivation therapy (ADT). For mCSPC, patients were classified as ARPI-exposed if they received an ARPI within 180 days of initiating ADT, while patients with nmCRPC were classified as ARPI-exposed if they received an ARPI within 2 years of diagnosis.

RESULTS

This study included 976 patients with mCSPC and 233 with nmCRPC of which 33.5% and 25.3% received an ARPI, respectively. The proportion of patients with mCSPC treated with an ARPI increased considerably for patients diagnosed in 2020 compared to 2017 (56.2% vs. 6.0%). In contrast, the use of ARPI to treat nmCRPC only increased marginally from 2017 to 2019/2020 (19.7% vs. 28.9%). Patients with mHSPC who were ARPI-exposed had longer median survival than patients who were ARPI-naive (38.47 (95% CI = 32.84-NA) vs. 34.19 (95% CI = 33.33-38.83; P = .03)), with a higher proportion of patients surviving to 2-years. For nmCRPC, survival was similar between ARPI-exposed and ARPI-naive. In multivariable analyses, receiving ARPI for mCSPC was associated with younger patient age, more recent diagnoses, fewer comorbidities, a higher number of metastatic sites, referral to a medical oncologist as well as receiving surgery and radiation before ADT. Receiving ARPI for nmCRPC was associated with referral to a medical oncologist, younger age, and more recent diagnoses.

CONCLUSIONS

Outcome analyses in this population suggest a continued unmet clinical need and complex clinical management pathways. Given that treatment pathways have evolved considerably, continued follow-up to understand the impact of these advancements on patient outcomes are warranted.

EAU-EANM-ESTRO-ESUR-ISUP-SIOG Guidelines on Prostate Cancer. Part II-2024 Update: Treatment of Relapsing and Metastatic Prostate Cancer

BACKGROUND AND OBJECTIVE

The European Association of Urology (EAU)-European Association of Nuclear Medicine (EANM)-European Society for Radiotherapy and Oncology (ESTRO)-European Society of Urogenital Radiology (ESUR)-International Society of Urological Pathology (ISUP)-International Society of Geriatric Oncology (SIOG) guidelines on the treatment of relapsing, metastatic, and castration-resistant prostate cancer (PCa) have been updated. Here we provide a summary of the 2024 guidelines.

METHODS

The panel performed a literature review of new data, covering the time frame between 2020 and 2023. The guidelines were updated and a strength rating for each recommendation was added on the basis of a systematic review of the evidence.

KEY FINDINGS AND LIMITATIONS

Risk stratification for relapsing PCa after primary therapy may guide salvage therapy decisions. New treatment options, such as androgen receptor-targeted agents (ARTAs), ARTA + chemotherapy combinations, PARP inhibitors and their combinations, and prostate-specific membrane antigen-based therapy have become available for men with metastatic PCa.

CONCLUSIONS AND CLINICAL IMPLICATIONS

Evidence for relapsing, metastatic, and castration-resistant PCa is evolving rapidly. These guidelines reflect the multidisciplinary nature of PCa management. The full version is available online (http://uroweb.org/guideline/ prostate-cancer/).

PATIENT SUMMARY

This article summarises the 2024 guidelines for the treatment of relapsing, metastatic, and castration-resistant prostate cancer. These guidelines are based on evidence and guide doctors in discussing treatment decisions with their patients. The guidelines are updated every year.

Systemic therapy landscape of advanced prostate cancer

Prostate cancer is the most commonly diagnosed cancer in American men and 2nd leading cause of cancer-related deaths in the United States. Androgen deprivation therapy (ADT) is the backbone of treatment for advanced prostate cancer. Over the past several decades a number of new therapeutics, such as novel androgen receptor pathway inhibitors, targeted agents and radionuclide therapies, have been introduced for the treatment of prostate cancers. These agents have been demonstrated to improve clinical outcomes of prostate cancer patients in randomized clinical trials. In addition, new therapeutic strategies, such as early intensification of ADT, novel treatment combinations, and treatment sequencing, are expected to improve outcomes further. In this clinical review, we discuss the changing treatment landscape for advanced prostate cancer with a focus on new therapeutics.

A practical guide for the use of apalutamide for non-metastatic castration-resistant prostate cancer in Australia

Studies of patients with castrate-resistant prostate cancer at high risk of developing overt metastases but with no current evidence of evaluable disease on computed tomography or bone scan non-metastatic castrate-resistant prostrate cancer have demonstrated increased metastasis-free survival and overall survival following treatment with the next-generation oral anti-androgen apalutamide (in addition to therapies that aim to lower testosterone to castrate levels) or luteinizing hormone-releasing hormone antagonist or surgical castration. Patients receiving apalutamide can be managed by medical oncologists, radiation oncologists, or urologists, preferably as part of a multidisciplinary team. However, the importance of additional safety monitoring for significant adverse effects and drug interactions should not be underestimated. The toxicities of apalutamide are manageable with experience and should be managed proactively to minimize their impact on patients. Monitoring of patients for apalutamide-specific toxicities, including skin rash, hypothyroidism, and QT prolongation should be carried out regularly, particularly in the first few months following initiation. Monitoring should continue alongside monitoring for toxicities of androgen deprivation, including cardiovascular risk, hot flashes, weight gain, bone health, muscle wasting, and diabetic risk. This review is a practical guide to the use of apalutamide describing the management of patients including dosing and administration, toxicities, potential drug interactions, and safety monitoring requirements.

Role of enzalutamide in primary and recurrent non-metastatic hormone sensitive prostate cancer: a systematic review of prospective clinical trials

INTRODUCTION

Enzalutamide, a second-generation androgen receptor inhibitor, is indicated for the treatment of metastatic disease, as well as in the treatment of non-metastatic castration resistant prostate cancer (PCa). This systematic review aims to determine outcomes and toxicity in patients with non-metastatic castration sensitive prostate cancer (nmCSPC) treated with enzalutamide in the primary or salvage settings.

METHOD

We performed a systematic review focusing on the role of Enzalutamide in the treatment of nmCSPC, using the PubMed/Medline database. Articles focusing on androgen receptor inhibitors in nmCSPC were included, while articles discussing exclusively metastatic or castration-resistant PCa were excluded.

RESULTS

The initial search retrieved 401 articles, of which 15 underwent a thorough assessment for relevance. Ultimately, 12 studies with pertinent outcomes were meticulously examined. Among these, seven studies were dedicated to the investigation of enzalutamide in the primary setting, while the remaining five publications specifically addressed its use in salvage settings. Regardless of the treatment setting, our data revealed two distinct therapeutic strategies. The first advocates for the substitution of enzalutamide for androgen deprivation therapy (ADT), based on the premise of achieving equivalent, if not superior, oncological outcomes while minimizing treatment-related toxicity. The second, adopting a more conventional approach, entails augmenting the effectiveness of ADT by incorporating enzalutamide.

CONCLUSION

Enzalutamide has considerable potential as a therapeutic strategy for nmCSPC, either used alone or in combination with ADT in the primary or in the salvage settings. The use of enzalutamide instead of ADT is an appealing strategy. However, more trials will be required to further understand the efficacy and side-effect profile of enzalutamide monotherapy.

Plexin D1 emerges as a novel target in the development of neural lineage plasticity in treatment-resistant prostate cancer

Treatment-induced neuroendocrine prostate cancer (t-NEPC) often arises from adenocarcinoma via lineage plasticity in response to androgen receptor signaling inhibitors, such as enzalutamide. However, the specific regulators and targets involved in the transition to NEPC are not well understood. Plexin D1 (PLXND1) is a cellular receptor of the semaphorin (SEMA) family that plays important roles in modulating the cytoskeleton and cell adhesion. Here, we found that PLXND1 is highly expressed and positively correlated with neuroendocrine markers in patients with NEPC. High PLXND1 expression is associated with poorer prognosis in prostate cancer patients. Additionally, PLXND1 was upregulated and negatively regulated by androgen receptor signaling in enzalutamide-resistant cells. Knockdown or knockout of PLXND1 inhibit neural lineage pathways, suppressing NEPC cell proliferation, PDX tumor organoid viability, and xenograft tumor growth. Mechanistically, the chaperone protein HSP70 regulates PLXND1 protein stability through degradation, and inhibition of HSP70 decreases PLXND1 expression and NEPC organoid growth. In summary, our findings suggest that PLXND1 could be a new therapeutic target and molecular indicator for NEPC.

The Current Therapeutic Landscape for Metastatic Prostate Cancer

In 2024, there will be an estimated 1,466,718 cases of prostate cancer (PC) diagnosed globally, of which 299,010 cases are estimated to be from the US. The typical clinical approach for PC involves routine screening, diagnosis, and standard lines of treatment. However, not all patients respond to therapy and are subsequently diagnosed with treatment emergent neuroendocrine prostate cancer (NEPC). There are currently no approved treatments for this form of aggressive PC. In this review, a compilation of the clinical trials regimen to treat late-stage NEPC using novel targets and/or a combination approach is presented. The novel targets assessed include DLL3, EZH2, B7-H3, Aurora-kinase-A (AURKA), receptor tyrosine kinases, PD-L1, and PD-1. Among these, the trials administering drugs Alisertib or Cabozantinib, which target AURKA or receptor tyrosine kinases, respectively, appear to have promising results. The least effective trials appear to be ones that target the immune checkpoint pathways PD-1/PD-L1. Many promising clinical trials are currently in progress. Consequently, the landscape of successful treatment regimens for NEPC is extremely limited. These trial results and the literature on the topic emphasize the need for new preventative measures, diagnostics, disease specific biomarkers, and a thorough clinical understanding of NEPC.

A multidisciplinary approach to address unmet needs in the management of patients with non-metastatic castration-resistant prostate cancer

BACKGROUND

With the availability of second-generation androgen receptor inhibitors (SGARIs), the treatment landscape has changed dramatically for patients with nonmetastatic castration-resistant prostate cancer (nmCRPC). In clinical trials, the SGARIs (apalutamide, enzalutamide, darolutamide) increased metastasis-free survival (MFS), overall survival (OS), and patient quality of life compared to placebo. These drugs were subsequently integrated into nmCRPC clinical practice guidelines. With advances in radiographic imaging, disease assessment, and patient monitoring, nmCRPC strategies are evolving to address limitations related to tracking disease progression using prostate-specific antigen (PSA) kinetics.

METHODS

A panel of 10 multidisciplinary experts in prostate cancer conducted reviews and discussions of unmet needs in the management and monitoring of patients with nmCRPC in order to develop consensus recommendations.

RESULTS

Across the SGARI literature, patient MFS and OS are generally comparable for all treatments, but important distinctions exist regarding short- and long-term drug safety profiles and drug-drug interactions. With respect to disease monitoring, a substantial proportion of patients using SGARIs may experience disease progression without rising PSA levels, suggesting a need for enhanced radiographic imaging in addition to PSA monitoring. Recent data also indicate that novel prostate-specific membrane antigen positron emission tomography radiotracers provide enhanced accuracy for disease detection, as compared to conventional imaging.

CONCLUSIONS

Clinical decision-making in nmCRPC has become more complex, with new opportunities to apply precision medicine to patient care. Multidisciplinary teams can ensure that patients with nmCRPC receive optimal and individualized disease management.

Real-world effects of novel androgen receptor axis-targeted agents on oncological outcomes in non-metastatic castration-resistant prostate cancer: A multi-institutional retrospective study

Background

The benefits of novel androgen receptor axis-targeted agents (ARATs) on oncological outcomes in patients with non-metastatic castration-resistant prostate cancer (nmCRPC) in real-world settings are unclear.

Methods

This multi-institutional retrospective study included 178 patients with nmCRPC treated between September 2003 and August 2022. Patients were divided into two groups: those who were treated with any novel ARATs, including apalutamide, enzalutamide, darolutamide, and abiraterone acetate, during any line of nmCRPC treatment (novel ARATs group) and those who were not (control group). Multivariable Cox proportional hazards regression analyses were performed to evaluate the effects of novel ARATs on metastasis-free survival (MFS) and overall survival (OS).

Results

The median age and follow-up period after nmCRPC diagnosis were 76 years and 37 months, respectively. Of the 178 patients, 122 (69%) were treated with novel ARATs after nmCRPC diagnosis. The MFS and OS in the novel ARATs group were significantly longer than those in the control group (P < 0.001 and P = 0.020, respectively). In multivariable analyses, a prostate-specific antigen doubling time (PSADT) of <3 months and novel ARATs were independently and significantly associated with MFS and OS. The effects of novel ARATs on MFS were consistently observed across subgroups stratified by age (<75 years or ≥75 years), history of radical treatment (no or yes), biopsy Gleason score (<9 or ≥9), clinical stage (≤cT3 and cN0, or cT4 or cN1), and PSADT (≥3 months or <3 months).

Conclusion

Novel ARATs were significantly associated with improved oncological outcomes in patients with nmCRPC in a real-world setting, regardless of tumor aggressiveness.

Lysine methyltransferase SMYD2 enhances androgen receptor signaling to modulate CRPC cell resistance to enzalutamide

Androgen receptors (ARs) play key roles in prostate cancer (PCa) progression and castration-resistant prostate cancer (CRPC) resistance to drug therapy. SET and MYND domain containing protein 2 (SMYD2), a lysine methyltransferase, has been reported to promote tumors by transcriptionally methylating important oncogenes or tumor repressor genes. However, the role of SMYD2 in CRPC drug resistance remains unclear. In this study, we found that SMYD2 expression was significantly upregulated in PCa tissues and cell lines. High SMYD2 expression indicated poor CRPC-free survival and overall survival in patients. SMYD2 knockdown dramatically inhibited the proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT) potential of 22Rv1 and C4-2 cells. Conversely, ectopic overexpression of SMYD2 promoted these effects in 22Rv1 and C4-2 cells. Mechanistically, SMYD2 methylated and phosphorylated ARs to affect AR ubiquitination and proteasome degradation, which further alters the AR transcriptome in CRPC cells. Importantly, the SMYD2 inhibitor AZ505 had a synergistic therapeutic effect with enzalutamide in CRPC cells and mouse models; however, it could also re-sensitize resistant CRPC cells to enzalutamide. Our findings demonstrated that SMYD2 enhances the methylation and phosphorylation of ARs and affects AR ubiquitination and proteasome degradation to modulate CRPC cell resistance to enzalutamide, indicating that SMYD2 serves as a crucial oncogene in PCa and is an ideal therapeutic target for CRPC.

Contemporary Systemic Therapy Intensification for Prostate Cancer: A Review for General Practitioners in Oncology

Prostate cancer accounts for a significant proportion of cancer diagnoses in Canadian men. Over the past decade, the therapeutic landscape for the management of metastatic prostate cancer has undergone rapid changes. Novel strategies use hormonal agents, chemotherapy, homologous recombination repair inhibitors, and radioligand therapy or combination strategies in addition to androgen deprivation therapy. In this review, we summarize the available data addressing key therapeutic areas along the disease continuum and focus on practical aspects for general practitioners in oncology managing patients with metastatic prostate cancer.

Correlation between E-cadherin/β-catenin, Vimentin expression, clinicopathologic features and drug resistance prediction in naïve prostate cancer: A molecular and clinical study

Although epithelial-mesenchymal markers play an important role in prostate cancer (PC), further research is needed to better understand their utility in diagnosis, cancer progression prevention, and treatment resistance prediction. Our study included 111 PC patients who underwent transurethral resection, as well as 16 healthy controls. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was used to examine the expression of E-cadherin, β-catenin, and Vimentin. We found that E-cadherin and β-catenin were underexpressed in primary PC tissues. E-cadherin expression was found to be inversely associated with prostate-specific antigen progression (PSA-P; serum marker of progression; p = 0.01; |r| = 0.262). Furthermore, the underexpression of two markers, E-cadherin and β-catenin, was found to be associated with advanced tumor stage and grade (p < 0.05). On the other hand, Vimentin was overexpressed in PC patients with a fold change of 2.141, and it was associated with the diagnosis, prognosis, and prediction of treatment resistance to androgen deprivation therapy (p = 0.002), abiraterone-acid (p = 0.001), and taxanes (p = 0.029). Moreover, the current study highlighted that poor survival could be significantly found in patients who progressed after primary surgery, did not use drugs, and expressed these genes aberrantly. In Cox regression multivariate analysis (p < 0.05), a positive correlation between the Vimentin marker and coronary heart disease in PC patients was identified (p = 0.034). In summary, the present study highlights the diagnostic (p < 0.001), prognostic (p < 0.001), and therapeutic potential of Vimentin in primary PC (p < 0.05), as well as its implications for cardiovascular disease. Furthermore, we confirm the potential prognostic value of E-cadherin and β-catenin.

Survival outcome of chemotherapy-naïve castration-resistant prostate cancer treated with new-generation androgen receptor axis-targeted agents in real-world analysis

PURPOSE

The androgen receptor axis-targeted (ARAT) agents abiraterone and enzalutamide have been introduced against castration-resistant prostate cancer (CRPC). However, determining which of these agents should be used first is a clinical challenge. Therefore, in this study, we compared the efficacy of first-line abiraterone and enzalutamide treatments in chemotherapy-naïve patients with CRPC.

METHODS

A total of 242 chemotherapy-naïve CRPC cases treated with first-line ARAT were analyzed. Outcome measures were PSA response, PSA progression-free survival (PSA-PFS), time to treatment failure (TTF), cancer specific survival (CSS), and overall survival (OS).

RESULTS

Abiraterone (A) and enzalutamide (E) were administered to 61 and 181 patients, respectively. The median PSA response rate (- 65.4% [A] and - 78.8% [E], p = 0.0341), PSA decline ≥ 30% (55.7% [A] and 72.9% [E], p = 0.0183), PSA-PFS (median 4 months [A] and 8 months [E], p = 0.0126), TTF (median 6 months [A] and 14 months [E], p < 0.0001), CSS (median 45 months [A] and not reached [E], p < 0.0001), and OS (median 28 months [A] and 80 months [E], p < 0.001) were significantly better in the enzalutamide group. In the multivariate analyses for CSS and OS, ALP (p = 0.00376) and ARAT (p < 0.001) (CSS), evidence of metastasis (p = 0.0467), Hb (p = 0.00205), and ARAT (p = 0.00514) (OS) were significant factors, respectively.

CONCLUSION

This study showed that PSA response, PSA-PFS, TTF, CSS, and OS were better with first-line enzalutamide administration. Direct inhibition of androgen receptor signaling by enzalutamide is associated with better clinical outcomes.

Impact of PSMA PET on Prostate Cancer Management

OPINION STATEMENT

PSMA-PET has been a practice-changing imaging biomarker for the management of men with PCa. Research suggests improved accuracy over conventional imaging and other PET radiotracers in many contexts. With multiple approved PSMA-targeting radiotracers, PSMA PET will become even more available in clinical practice. Its increased use requires an understanding of the prospective data available and caution when extrapolating from prior trial data that utilized other imaging modalities. Future trials leveraging PSMA PET for treatment optimization and management decision-making will ultimately drive its clinical utility.

Cardiovascular risks of androgen receptor targeted agents in prostate cancer: a systematic review and meta-analysis

INTRODUCTION

Androgen receptor targeted agents (ARTA) have increasingly been incorporated into treatment regimens for various stages of prostate cancer. Patients are living longer with prostate cancer, and thus have a higher cumulative exposure to the treatment and its accompanying side effects, especially those of cardiovascular disease. We aim to assess the differences in the incidence of cardiac-related adverse events after treatment of prostate cancer with ARTA versus placebo.

METHODS

Three databases were thoroughly searched for relevant articles. The PICOS model was used to frame our clinical question, with which 2 independent authors went through several rounds of screening to select the final included studies. Meta-analysis was done using the Cochran-Mantel-Haenszel Method. Quality assessment was carried out with the Cochrane Risk of Bias tool RoB 2.

RESULTS

The use of ARTA in prostate cancer increases the incidence of cardiac-related adverse events (RR: 1.56, 95% CI: 1.29-1.90, p < 0.00001), such as hypertension (RR: 1.69, 95% CI: 1.46-1.97, p < 0.00001), ischaemic heart disease (RR: 1.84, 95% CI: 1.36-2.50, p < 0.0001), and arrhythmia (RR: 1.38, 95% CI: 1.11-1.71, p = 0.004), although this did not manifest in an increased incidence of cardiac arrests/deaths (RR: 1.28, 95% CI: 0.87-1.88, p = 0.21).

DISCUSSION

ARTA increases the risk of cardiac-related adverse events, hypertension, ischaemic heart disease and arrhythmia. Armed with this knowledge, we will be better poised to manage cardiac risks accordingly and involve a cardiologist as required when starting patients on ARTA.

Enzalutamide versus Abiraterone Plus Prednisolone for Nonmetastatic Castration-Resistant Prostate Cancer: A Sub-Analysis from the ENABLE Study for PCa

Enzalutamide (ENZ) and abiraterone plus prednisolone (ABI) can improve the survival of patients with castration-resistant prostate cancer (CRPC). However, the agent that is more effective against nonmetastatic CRPC remains unclear. To evaluate the agent that can be used as the first-line treatment for CRPC, an investigator-initiated, multicenter, randomized controlled trial (ENABLE Study for PCa) including both metastatic and nonmetastatic CRPC was conducted in Japan. The prostate-specific antigen (PSA) response rate, overall survival, some essential survival endpoints, and safety of patients with nonmetastatic CRPC were also analyzed. In this subanalysis, 15 and 26 patients in the ENZ and ABI arms, respectively, presented with nonmetastatic CRPC. There was no significant difference in terms of the PSA response rate between the ENZ and ABI arms (80% and 64%, respectively; p = 0.3048). The overall survival did not significantly differ between the two arms (HR: 0.68; 95% CI: 0.22-2.14, p = 0.5260). No significant differences were observed in terms of radiographic progression-free survival and cancer-specific survival between the ENZ and ABI arms (HR: 0.81; 95% CI: 0.35-1.84; p = 0.6056 and HR: 0.72; 95% CI: 0.19-2.73; p = 0.6443, respectively). Only four and six patients in the ENZ and ABI arms, respectively, had ≥grade 3 adverse events. ABI and ENZ had similar efficacy and safety profiles in patients with nonmetastatic CRPC.

Improving the identification of high-risk non-metastatic castration-resistant prostate cancer patients in clinical practice

Non-metastatic castration-resistant prostate cancer (nmCRPC) represents a challenging disease state in prostate cancer care. nmCRPC patients with a high risk of progression to metastatic disease who are identified by a prostate-specific antigen doubling time (PSADT) ≤10 months are eligible for treatment with the novel androgen receptor inhibitors (ARIs), shown to delay disease progression and extend survival. However, nmCRPC is often unexploited in clinical practice due to a lack of standardization in the methodology and in the tools used for its identification. In this article, a group of Urology and Oncology specialists with acknowledged expertise in prostate cancer reviews the state of the art in the management of high-risk nmCRPC patients, identifies gaps and unmet needs, and proposes strategies to optimize the identification of this patient subgroup in the clinical practice and improve their health outcomes.

Standardized PSMA-PET Imaging of Advanced Prostate Cancer

Imaging of advanced prostate cancer is a challenging task, as it requires longitudinal characterization of disease extent in a standardized way to enable appropriate treatment selection and evaluation of treatment efficacy. In the last years, prostate-specific membrane antigen (PSMA)-PET/CT has become the reference standard examination for patients with advanced prostate cancer. Together with the rise of PSMA-PET, standardized frameworks for the reporting of image findings have been proposed, eg, the Prostate Cancer Molecular Imaging Standardized Evaluation (PROMISE) and the structured reporting system for PSMA targeted PET imaging (PSMA-RADS) framework. Therefore, recent evidence on PSMA-PET derived tumor volume as useful a biomarker for outcome prognostication and related frameworks will be discussed in the article. The PROMISE framework recommends quantifying the tumor volume per-organ system, which accounts for the fact that the location of the metastases greatly influence its biological aggressiveness. In addition, changes in PSMA-PET derived tumor volume have been shown to be promising biomarkers for response assessment. Limitations of PSMA-PET will also be discussed because the tumor volume might not always be suited for response assessment. As a pitfall of PSMA-based systems, decreasing PSMA-expression might erroneously be interpreted as response to therapy. Also, especially for patients with limited disease, the tumor volume might not be ideal for response assessment. Therefore, various frameworks have been introduced to objectively measure response to therapy with PSMA-PET. Amongst these, the PSMA-PET progression (PPP) criteria and the response evaluation criteria in PSMA (RECIP) are optimized for earlier and later phenotypes of advanced prostate cancer, respectively. Variables needed to determine PPP or RECIP outcome on PSMA-PET are recorded under the umbrella of PROMISE recommendations. In this article, various reporting and response assessment frameworks are explained and discussed. Also, recent evidence for the relevance of PSMA-PET biomarkers for clinical management and outcome prognostication are shown.

LncRNA BRCAT54 is downregulated and inhibits cancer cell proliferation by downregulating miR-130b-3p through methylation in prostate cancer

BRCAT54 and miR-130b-3p are two recently characterized critical players in cancer biology, while their functions in prostate cancer (PC) are unknown. From preliminary sequencing analysis, we observed altered expression of BRCAT54 and miR-130b-3p in PC and an inverse correlation between them. This study was conducted to explore their involvement in PC. A total of 64 PC patients were enrolled to collect paired PC and nontumor tissues. The expression of BRCAT54 and miR-130b-3p were determined by RT-qPCR. Overexpression of BRCAT54 and miR-130b-3p was achieved in PC cells to explore their roles in regulating the expression of each other. Methylation-specific PCR (MSP) was conducted to explore the role of BRCAT54 in regulating promoter methylation of miR-130b-3p. BrdU assay was used to evaluate the role of BRCAT54 and miR-130b-3p in regulating PC cell proliferation. The results showed that PC tissues exhibited downregulation of BRCAT54 and upreglation of miR-130b-3p compared to that in nontumor tissues. They were inversely correlated across PC tissue samples. Overexpression of BRCAT54 decreased RNA accumulation of miR-130b-3p in PC cells. In addition, overexpression of BRCAT54 increased promoter methylation of miR-130b-3p. Moreover, BRCAT54 suppressed the role of miR-130b-3p in promoting PC cell proliferation. In conclusion, BRCAT54 is downregulated in PC and it may inhibit cancer cell proliferation by downregulating miR-130b-3p through methylation.

Perspectives on prostate cancer: advances and pending challenges for a multidisciplinary oncological approach in South America

Prostate cancer is one of the tumors with the highest incidence and mortality among men worldwide, and this situation is no different in South America. However, epidemiological data are highly variable for each country and even more so than in North America. These data may be influenced by the very low rate of early detection of disease, availability of diagnostic methods, proper data collection, and limited access to specialized multidisciplinary treatment. For many South American countries, academic referral centers can only offer state-of-the-art diagnostics and multidisciplinary cancer treatment for patients who live in or can travel to large cities, so most patients are cared for by non-expert urologists with limited resources, which can have a negative impact on their prognosis and worsen oncologic outcomes. We aimed to show the clinical management of prostate cancer patients, the current advances in management, limitations present in South America, and how a multidisciplinary approach in referral cancer centers conformed of specialized urologists, medical oncologists, and mental health professionals can maximize patient outcomes.

Adverse events and costs among non-metastatic castration-resistant prostate cancer patients

BACKGROUND

Limited real-world evidence exists on the economic burden of adverse events (AEs) to the healthcare system among patients with non-metastatic castration-resistant prostate cancer (nmCRPC) treated with second-generation androgen receptor antagonists (ARAs). Current data is needed to understand real-world clinical event rates among ARAs and the cost of these events.

OBJECTIVES

Describe the incidence of non-central nervous system (CNS)-related AEs and CNS-related AEs among nmCRPC patients treated in the United States with second-generation ARAs (apalutamide and enzalutamide) and evaluate healthcare resource utilization (HCRU) and costs for these patients.

METHODS AND STUDY DESIGN

This was a retrospective observational cohort study using claims data from Optum Clinformatics Data Mart to identify adult males with prostate cancer, castration, no metastases, and >1 claim for apalutamide or enzalutamide. The study was conducted from January 2017 to March 2020, with a patient index identification period from January 2018 to December 2019. AEs were classified as CNS-related or non-CNS-related.

RESULTS

Of 605 patients (156 apalutamide and 449 enzalutamide), most were ≥65 years (94%) and had ≥1 non-CNS-related AE (55%). Many had ≥1 CNS-related AE (32%). Pain (12%) and arthralgia (11%) were the most frequently reported non-CNS-related AEs. Fatigue/asthenia (14%) and dizziness (7%) were the most frequently reported CNS-related AEs. Among patients with versus without non-CNS-related AEs, 34% versus 8% had emergency room (ER) events, and 25% versus 2% had inpatient events. Among patients with versus without CNS-related AEs, 41% versus 14% had ER events, and 38% versus 4% had inpatient events. Adjusted per-patient per-year cost (in 2020 USD) differences were significant between patients with and without non-CNS-related AEs ($30,765, p = 0.0018) and between patients with and without CNS-related AEs ($40,689, p = 0.0017).

CONCLUSION

There is significant HCRU and cost burden among nmCRPC patients treated with ARAs developing AEs, highlighting the need for treatments with improved tolerability. Additional studies are warranted to include recently approved agents.

Management and health-related quality of life among patients with prostate cancer in a Kenyan tertiary health facility

INTRODUCTION

Advances made in the screening, diagnosis and management of prostate cancer have improved the survival rates of the patients. However, many of these treatments including surgery, radiotherapy, and pharmacotherapy, have an impact on the subsequent health-related quality of life (HRQoL) of these patients. Since it is an important prognostic factor of survival, failure to evaluate the HRQoL and its predictors in these patients typically results in long-term deficits in their overall well-being, that is, their physical, social, emotional, and mental health. The objective of this study was to evaluate the management and HRQoL among patients with prostate cancer at Kenyatta National Hospital.

METHODS

This was a descriptive cross-sectional study. The sample size of 62 patients who met the eligibility criteria was selected through simple random sampling on the respective clinic days of the cancer treatment centre and urology clinic. Data was collected through a pre-tested structured questionnaire and HRQoL tools which are EORTC-QLQ-C30 and EORTC-QLQ-PR25 and analysed using STATA version 13 software. Descriptive analysis was used to summarise the continuous and categorical variables. Spearman's rho (rs) correlation was used to determine the predictors of HRQoL based on the strength and significance of association at 0.05 level of significance.

RESULTS

The mean age of the participants was 70.5 (±7.35) years. The majority (52, 83.9%) of the patients had a prostate specific antigen (PSA) above 20 ng/ml. Twenty-one (33.9%) were graded as Gleason group 5 and 41 (66.1%) had stage IV disease at diagnosis. Fifty (80.9%) participants were on hormonal therapy, with most of them being on combined androgen blockade. The overall HRQoL was 65.1. Fatigue, one of the major complaints among these patients, was negatively associated with physical functioning (p = 0.0005), role functioning (p = 0.0026), social functioning (p = 0.0001), financial difficulties (p = 0.0077) and quality of life (p = 0.0050).

CONCLUSION

Fatigue was the most common predictor of poor HRQoL in several scales of measurement. For those on management, frequent assessment of HRQoL should be carried out and interventions instituted immediately.

Understanding the role of Pax5 in development of taxane-resistant neuroendocrine like prostate cancers

Resistance to the current Androgen Receptor Signaling Inhibitor (ARSI) therapies has led to higher incidences of therapy-induced neuroendocrine-like prostate cancer (t-NEPC). This highly aggressive subtype with predominant small cell-like characteristics is resistant to taxane chemotherapies and has a dismal overall survival. t-NEPCs are mostly treated with platinum-based drugs with a combination of etoposide or taxane and have less selectivity and high systemic toxicity, which often limit their clinical potential. During t-NEPC transformation, adenocarcinomas lose their luminal features and adopt neuro-basal characteristics. Whether the adaptive neuronal characteristics of t-NEPC are responsible for such taxane resistance remains unknown. Pathway analysis from patient gene-expression databases indicates that t-NEPC upregulates various neuronal pathways associated with enhanced cellular networks. To identify transcription factor(s) (TF) that could be important for promoting the gene expression for neuronal characters in t-NEPC, we performed ATAC-Seq, acetylated-histone ChIP-seq, and RNA-seq in our NE-like cell line models and analyzed the promoters of transcriptionally active and significantly enriched neuroendocrine-like (NE-like) cancer-specific genes. Our results indicate that Pax5 could be an important transcription factor for neuronal gene expression and specific to t-NEPC. Pathway analysis revealed that Pax5 expression is involved in axonal guidance, neurotransmitter regulation, and neuronal adhesion, which are critical for strong cellular communications. Further results suggest that depletion of Pax5 disrupts cellular interaction in NE-like cells and reduces surface growth factor receptor activation, thereby, sensitizing them to taxane therapies. Moreover, t-NEPC specific hydroxymethylation of Pax5 promoter CpG islands favors Pbx1 binding to induce Pax5 expression. Based on our study, we concluded that continuous exposure to ARSI therapies leads to epigenetic modifications and Pax5 activation in t-NEPC, which promotes the expression of genes necessary to adopt taxane-resistant NE-like cancer. Thus, targeting the Pax5 axis can be beneficial for reverting their taxane sensitivity.

Role of apalutamide in the treatment landscape for patients with advanced prostate cancer: an expert opinion statement of European clinical practice

BACKGROUND

Patients with advanced prostate cancer have a poor prognosis, and well-tolerated new treatment strategies are required to improve survival outcomes. Apalutamide is a novel androgen signalling inhibitor developed to be used in combination with continuous androgen deprivation therapy (ADT) for the treatment of patients with advanced prostate cancer. Based on evidence from two phase 3 pivotal clinical trials in non-metastatic castration-resistant (nmCRPC; SPARTAN) and metastatic hormone-sensitive prostate cancer (mHSPC; TITAN), ADT plus apalutamide significantly extends overall survival compared with the standard of care.

AIMS

To provide practical recommendations to guide optimal use in the real-world setting as the use of apalutamide in clinical practice increases.

METHODS

Expert opinion from a group of European physicians is presented here to educate on the use of apalutamide in combination with ADT in patients with mHSPC and patients with nmCRPC who are at risk of developing metastatic disease, focusing on practical considerations such as patient selection, monitoring, and management of side effects.

RESULTS

In clinical practice, apalutamide in combination with ADT can be used in a broad patient population including patients with high and low volume/risk mHSPC, patients with de novo metastatic disease or metastases following treatment for localised disease, as well as older patients. Apalutamide in combination with ADT is well tolerated, with manageable side effects which do not impact health-related quality of life compared to ADT alone.

CONCLUSIONS

Real-world experience with apalutamide supports the efficacy and safety findings reported by the SPARTAN and TITAN clinical trials.

Racial and Ethnic Disparities in Use of Novel Hormonal Therapy Agents in Patients With Prostate Cancer

Importance

Novel hormonal therapy (NHT) agents have been shown to prolong overall survival in numerous randomized clinical trials for patients with advanced prostate cancer (PCa). There is a paucity of data regarding the pattern of use of these agents in patients from different racial and ethnic groups.

Objective

To assess racial and ethnic disparities in the use of NHT in patients with advanced PCa.

Design, Setting, and Participants

This cohort study comprised all men diagnosed with de novo advanced PCa (distant metastatic [M1], regional [N1M0], and high-risk localized [N0M0] per Systemic Therapy in Advancing or Metastatic Prostate Cancer: Evaluation of Drug Efficacy [STAMPEDE] trial criteria) with Medicare Part A, B, and D coverage between January 1, 2011, and December 31, 2017, in a Surveillance, Epidemiology, and End Results (SEER)-Medicare linked database including prescription drug records. Data analysis took place from January through May 2023.

Exposures

Race and ethnicity (Black [non-Hispanic], Hispanic, White, or other [Alaska Native, American Indian, Asian, Pacific Islander, or not otherwise specified and unknown]) abstracted from the SEER data fields.

Main Outcomes and Measures

The primary outcome was receipt of an NHT agent (abiraterone, enzalutamide, apalutamide, or darolutamide) using a time-to-event approach.

Results

The study included 3748 men (median age, 75 years [IQR, 70-81 years]). A total of 312 (8%) were Black; 263 (7%), Hispanic; 2923 (78%), White; and 250 (7%) other race and ethnicity. The majority of patients had M1 disease (2135 [57%]) followed by high-risk N0M0 (1095 [29%]) and N1M0 (518 [14%]) disease. Overall, 1358 patients (36%) received at least 1 administration of NHT. White patients had the highest 2-year NHT utilization rate (27%; 95% CI, 25%-28%) followed by Hispanic patients (25%; 95% CI, 20%-31%) and patients with other race or ethnicity (23%; 95% CI, 18%-29%), with Black patients having the lowest rate (20%; 95% CI, 16%-25%). Black patients had significantly lower use of NHT compared with White patients, which persisted at 5 years (37% [95% CI, 31%-43%] vs 44% [95% CI, 42%-46%]; P = .02) and beyond. However, there was no significant difference between White patients and Hispanic patients or patients with other race or ethnicity in NHT utilization (eg, 5 years: Hispanic patients, 38% [95% CI, 32%-46%]; patients with other race and ethnicity: 41% [95% CI, 35%-49%]). Trends of lower utilization among Black patients persisted in the patients with M1 disease (eg, vs White patients at 5 years: 51% [95% CI, 44%-59%] vs 55% [95% CI, 53%-58%]). After adjusting for patient, disease, and sociodemographic factors in multivariable analysis, Black patients continued to have a significantly lower likelihood of NHT initiation (adjusted subdistribution hazard ratio, 0.76; 95% CI, 0.61-0.94, P = .01).

Conclusions and Relevance

In this cohort study of Medicare beneficiaries with advanced PCa, receipt of NHT agents was not uniform by race, with decreased use observed in Black patients compared with the other racial and ethnic groups, likely due to multifactorial obstacles. Future studies are needed to identify strategies to address the disparities in the use of these survival-prolonging therapies in Black patients.

Novel Approaches in the Systemic Management of High-Risk Prostate Cancer

Locally advanced prostate cancer comprises approximately 20% of new prostate cancer diagnoses. For these patients, international guidelines recommend treatment with radiotherapy (RT) to the prostate in combination with long-term (2-3 years) androgen deprivation therapy (ADT), or radical prostatectomy in combination with extended pelvic lymph node dissection (PLND) as another treatment option for selected patients as part of multimodal therapy. Improvements in overall survival with docetaxel or an androgen receptor signaling inhibitor have been achieved in patients with metastatic castration sensitive or castration resistant prostate cancer. However, the role of systemic therapy combinations for high risk and/or unfavorable prostate cancer is unclear. In this context, the aim of this review is to assess the current evidence for systemic treatment combinations as part of primary definitive therapy in patients with high-risk localized prostate cancer.

Treatment Landscape for Metastatic Castrate-Sensitive Prostate Cancer: A Review

With the advent of new therapeutic modalities, management of metastatic castrate-sensitive prostate cancer (mCSPC) has been in flux. From androgen-deprivation therapy to docetaxel to androgen receptor-signaling inhibitors, each agent has heralded a new treatment paradigm. As such, the optimal first-line therapy for mCSPC remains incompletely defined. This review provides a narrative of recent advances to systemic therapy within the mCSPC treatment space, particularly with regard to expansion to triplet therapy.

Updates in the Treatment of Non-Metastatic Castrate-Resistant Prostate Cancer: The Benefit of Second-Generation Androgen Receptor Antagonists

OBJECTIVE

To review pharmacology, efficacy, safety, and considerations for use, of second-generation androgen receptor (AR) antagonists in treatment of nonmetastatic castrate-resistant prostate cancer (M0CRPC).

DATA SOURCES

Conducted search in PubMed and Google scholar (January, 1, 2002-December 31, 2022), using relevant terms.

STUDY SELECTION AND DATA EXTRACTION

Relevant English-language studies, conducted in humans evaluating second-generation AR antagonists for M0CRPC, and additional articles and package inserts were considered.

DATA SYNTHESIS

Apalutamide, darolutamide, and enzalutamide are effective in delaying the time to development of metastatic prostate cancer in men with M0CRPC with a rapid prostate-specific antigen (PSA) doubling time (<10 months). No head-to-head, randomized, clinical trials have been conducted. The most common adverse effects include fatigue and hypertension, and quality of life is maintained in most patients. Cost is similar among the agents (~$15,000/month). Drug-drug interactions vary among these agents and should be considered, when selecting therapy as well as likely adherence. Darolutamide is administered twice daily with the others once daily.

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE

Second-generation AR antagonists are effective in reducing time to development of metastatic disease and prolonging overall survival in patients with M0CRPC and a PSA doubling time of <10 months. Recent imaging advances may alter how we evaluate outcomes.

CONCLUSIONS

Second-generation AR antagonists improve disease control and overall survival. Generally, they are well tolerated and QOL is maintained. Selection of the best agent is based on the adverse effect profile, potential for drug- and disease-interactions, administration, cost, and patient preference.

External validation of a risk model predicting failure of salvage focal ablation for prostate cancer

OBJECTIVES

To externally validate a published model predicting failure within 2 years after salvage focal ablation in men with localised radiorecurrent prostate cancer using a prospective, UK multicentre dataset.

PATIENTS AND METHODS

Patients with biopsy-confirmed ≤T3bN0M0 cancer after previous external beam radiotherapy or brachytherapy were included from the FOcal RECurrent Assessment and Salvage Treatment (FORECAST) trial (NCT01883128; 2014-2018; six centres), and from the high-intensity focussed ultrasound (HIFU) Evaluation and Assessment of Treatment (HEAT) and International Cryotherapy Evaluation (ICE) UK-based registries (2006-2022; nine centres). Eligible patients underwent either salvage focal HIFU or cryotherapy, with the choice based predominantly on anatomical factors. Per the original multivariable Cox regression model, the predicted outcome was a composite failure outcome. Model performance was assessed at 2 years post-salvage with discrimination (concordance index [C-index]), calibration (calibration curve and slope), and decision curve analysis. For the latter, two clinically-reasonable risk threshold ranges of 0.14-0.52 and 0.26-0.36 were considered, corresponding to previously published pooled 2-year recurrence-free survival rates for salvage local treatments.

RESULTS

A total of 168 patients were included, of whom 84/168 (50%) experienced the primary outcome in all follow-ups, and 72/168 (43%) within 2 years. The C-index was 0.65 (95% confidence interval 0.58-0.71). On graphical inspection, there was close agreement between predicted and observed failure. The calibration slope was 1.01. In decision curve analysis, there was incremental net benefit vs a 'treat all' strategy at risk thresholds of ≥0.23. The net benefit was therefore higher across the majority of the 0.14-0.52 risk threshold range, and all of the 0.26-0.36 range.

CONCLUSION

In external validation using prospective, multicentre data, this model demonstrated modest discrimination but good calibration and clinical utility for predicting failure of salvage focal ablation within 2 years. This model could be reasonably used to improve selection of appropriate treatment candidates for salvage focal ablation, and its use should be considered when discussing salvage options with patients. Further validation in larger, international cohorts with longer follow-up is recommended.

Natural killer cell activity in metastatic castration resistant prostate cancer patients treated with enzalutamide

Metastatic castration resistant prostate cancer (mCRPC) is still the lethal stage for the whole spectrum of prostate cancer disease. Even though different treatment options have been introduced in the last decade with a significant survival improvement for this population, a lack of more reliable prognostic and predictive markers is still one of the main clinical challenges in management of mCRPC. The aim of this study was to investigate the correlation between Natural Killer cell activity (NKA) and both treatment effect and outcomes in patients with mCRPC treated with enzalutamide. A total of 87 patients with mCRPC treated with enzalutamide as the first line treatment were enrolled. NKA was estimated at baseline and prior to each treatment cycle. Endpoints included both treatment effect with biochemical response (BR), biochemical progression (BP) and radiological progression (RP), as well as outcome data with overall survival (OS), radiologic progression free survival (rPFS), and time to next treatment (TTT). At the time of BR, interferon-gamma (IFNγ) decreased significantly compared to levels detected at baseline (z-score = 2.33, p = 0.019). Regarding outcome data, the whole cohort was divided into four groups according to the change of IFNγ level during the first 3 cycles of enzalutamide treatment. In group 1 (n = 42) the IFNγ level remained within a normal range (≥ 250 pg/mL),while in group 2 (n = 7) it increased from an abnormal (< 250 pg/mL) to a normal level. In group 3 (n = 13) it dropped to an abnormal level, and it remained at an abnormal level during treatment in group 4 (n = 17). Patients in group 2 showed the worst prognosis with shorter both rPFS and TTT (HR 4.30, p = 0.037; and HR 6.82, p = 0.011, respectively). In this study inverse correlations between NKA and both treatment response and outcomes was observed in mCRPC patients receiving enzalutamide, suggesting an unfavourable role of NK cells in the late stage of PCa.

Risk of Short-Term Prostate-Specific Antigen Recurrence and Failure in Patients With Prostate Cancer: A Secondary Analysis of a Randomized Clinical Trial

Importance

A shorter time interval to prostate-specific antigen (PSA) failure is associated with worse clinical outcomes; however, specific factors defining this state remain unknown.

Objective

To evaluate the factors of a short time interval to PSA failure in order to identify patients for treatment escalation randomized clinical trials.

Design, Setting, and Participants

This secondary analysis of a randomized clinical trial was a secondary analysis of the Dana-Farber Cancer Institute 05-043 trial and included 350 patients with nonmetastatic unfavorable risk prostate cancer (PC).

Interventions

Patients were randomized 1:1 to receive androgen deprivation therapy (ADT) and radiation therapy (RT) plus docetaxel vs ADT and RT.

Main Outcomes and Measures

Cumulative incidence rates curves of PSA failure, defined as PSA nadir plus 2 ng/mL or initiation of salvage therapies, and the Fine and Gray competing risks regression was used to assess the prognostic association between these factors and time to PSA failure.

Results

The study included 350 males who primarily had a good performance status (330 [94.3%] with Eastern Cooperative Oncology Group score of 0), median (range) age of 66 (43-86) years, with 167 (46.6%) having Gleason scores of 8 to 10, and 195 (55.2%) presenting with a baseline PSA of more than 10 ng/mL. After a median (IQR) follow-up of 10.2 (8.0-11.4) years, having a PSA level of 10 ng/mL to 20 ng/mL (subdistribution hazard ratio [sHR], 1.98; 95% CI, 1.28-3.07; P = .002) and a Gleason score of 8 to 10 (sHR, 2.55; 95% CI, 1.63-3.99; P < .001) were associated with a shorter time to PSA failure, and older age (sHR, 0.82; 95% CI, 0.72-0.93; P = .002) was associated with reduced risk for PSA failure after adjusting for other baseline clinical factors. The high-risk category, defined by these 3 factors, was associated with a shorter time to PSA failure (sHR, 2.69; 95% CI, 1.84-3.93; P < .001).

Conclusions and Relevance

In this secondary analysis of a randomized clinical trial of males with unfavorable risk PC, young age, PSA of 10 ng/mL or more, and a Gleason score of 8 to 10 estimated a shorter time to PSA failure. A subgroup of males at very high-risk for early PSA failure, as defined by our study, may benefit from treatment escalation with androgen receptor signaling inhibitors or cytotoxic chemotherapy and should be the subject of a prospective randomized clinical trial.

Trial Registration

NCT00116142.