Management of non-metastatic castrate-resistant prostate cancer: A systematic review

Targeting PI3K/Akt signaling in prostate cancer therapy

Urological cancers have obtained much attention in recent years due to their mortality and morbidity. The most common and malignant tumor of urological cancers is prostate cancer that imposes high socioeconomic costs on public life and androgen-deprivation therapy, surgery, and combination of chemotherapy and radiotherapy are employed in its treatment. PI3K/Akt signaling is an oncogenic pathway responsible for migration, proliferation and drug resistance in various cancers. In the present review, the role of PI3K/Akt signaling in prostate cancer progression is highlighted. The activation of PI3K/Akt signaling occurs in prostate cancer, while PTEN as inhibitor of PI3K/Akt shows down-regulation. Stimulation of PI3K/Akt signaling promotes survival of prostate tumor cells and prevents apoptosis. The cell cycle progression and proliferation rate of prostate tumor cells increase by PI3K/Akt signaling induction. PI3K/Akt signaling stimulates EMT and enhances metastasis of prostate tumor cells. Silencing PI3K/Akt signaling impairs growth and metastasis of prostate tumor cells. Activation of PI3K/Akt signaling mediates drug resistance and reduces radio-sensitivity of prostate tumor cells. Anti-tumor compounds suppress PI3K/Akt signaling in impairing prostate tumor progression. Furthermore, upstream regulators such as miRNAs, lncRNAs and circRNAs regulate PI3K/Akt signaling and it has clinical implications for prostate cancer patients.

How PET-CT is Changing the Management of Non-metastatic Castration-resistant Prostate Cancer?: Comment la TEP-TDM Peut Modifier la Prise en Charge du Cancer de la Prostate Non Métastatique Résistant à la Castration ?

INTRODUCTION

The aim of this narrative review conducted by the Prostate Cancer Committee of the French Association of Urology (CC-AFU) was to provide an update on the current evidence for the impact of PET/CT in the management of men with non-metastatic castration-resistant prostate cancer (nmCRPC).

MATERIAL AND METHODS

This review is based on data available in the literature on PET/CT imaging for staging nmCRPC patients. A PubMed search and narrative review of the data were performed in March 2022. Only articles in French or English were considered.

RESULTS

Current guidelines recommend bone scan and CT scan as standard imaging modalities for staging and follow-up of patients with nmCRPC. Nearly one-third of asymptomatic patients with presumed nmCRPC ultimately have metastatic disease on conventional imaging. Increasing reports have shown that conventional imaging has limited accuracy in detecting metastatic disease in nmCRPC patients, leading to the development of next-generation imaging techniques. In a retrospective study, 18F-choline PET/CT detected distant metastases in 27/58 high-risk nmCRPC patients with prior negative conventional imaging. The implementation of radiolabeled ligands of the prostate-specific membrane antigen (PSMA) PET/CT in staging strategy has resulted in metastasis detection in 45% to 98% of patients with presumptive nmCRPC on conventional imaging. Such an early diagnosis of metastatic CRPC may allow patients to be referred for metastasis-directed therapies (i.e. stereotactic body radiotherapy), aimed at prolonging the efficacy of systemic therapies and improving clinical outcomes. However, current data are not strong enough to recommend this strategy, which must be properly evaluated in clinical trials. Indeed, the use of molecular imaging may lead to inappropriate undertreatment if the second-generation androgen receptor inhibitors (darolutamide, enzalutamide, apalutamide), which prolong life, are not used in the subgroup of patients with high PSA velocity (PSA doubling time <10 months).

CONCLUSION

Implementation of PSMA-PET/CT in the staging strategy would result in a migration of disease stage to extra-pelvic, M1 disease in at least half of presumed nmCRPC patients. The unprecedented accuracy of PSMA-PET/CT may pave the way for a more personalized treatment strategy. However, no data yet support this strategy for all nmCRPC patients as no oncologic benefit of early detection of M1 disease or MDT has been demonstrated. © 2022 Elsevier Masson SAS. All rights reserved.

A meta-analysis on overall survival and safety outcomes in patients with nonmetastatic castration-resistant prostate cancer treated with novel hormonal agents

Several novel androgen receptor (AR)-inhibitors have been introduced for nonmetastatic castration-resistant prostate cancer (nmCRPC) treatment, with the improvement of survival outcomes which need to be balanced against the risk of adverse events. We performed a systematic review and meta-analysis of randomized controlled trials (RCTs) investigating enzalutamide, apalutamide and darolutamide in nmCRPC patients, to assess overall survival (OS), incidence and risk of adverse drug events, adverse-events-related death and adverse-events-related treatment discontinuation. We selected three RCTs (SPARTAN, PROSPER and ARAMIS). New hormonal agents administration resulted in better OS, despite the increased risk of several any grade and grade 3-4 adverse events. In the decision-making process, careful evaluation of expected adverse events, patients' comorbidities and maintenance of quality of life are mandatory.

Novel Androgen Receptor Inhibitors in Non-Metastatic, Castration-Resistant Prostate Cancer: A Systematic Review and Network Meta-Analysis

Introduction

Enzalutamide, apalutamide, and darolutamide have all been approved by Food and Drug Administration to treat high-risk non-metastatic castration-resistant prostate cancer (nmCRPC) since 2018 based on interim results of several phase III clinical trials. Final analyses of long-term overall survival (OS) and adverse events (AEs) results of these trials have been successively published recently. To help clinical practice to precisely select optimal treatment for high-risk nmCRPC patients, we performed a network meta-analysis to indirectly compare the final long-term results among these medications.

Methods

PubMed, EMBASE, and Cochrane Libraries were searched for phase III clinical trial that reports OS and AEs results in nmCRPC patients published before January 30, 2021. Primary outcome was OS; secondary outcomes were Time to first chemotherapy, Subsequent antineoplastic therapy rate, and AEs. Firstly, class-level effect was assessed as the second-generation androgen receptor antagonists (SGARAs) were regarded as one whole class compared with placebo through traditional meta-analysis by using Revman 5.4, then a Bayesian network meta-analysis was conducted to give indirect comparison among SGARAs by using R 3.5.3 software. Subgroup analysis of OS was only conducted in the certain subgroups which were available in all included studies.

Results

Three eligible studies including 4,104 participants were finally selected. OS was significantly improved by the SGARAs as a class compared with placebo (HR, 0.74; 95% CI, 0.66–0.84). Darolutamide had the highest likelihood of providing best OS (p-score=0.802). SGARAs also significantly delayed the first time to chemotherapy (HR, 0.58; 95% CI, 0.50–0.66). Patients who received darolutamide experienced similar toxicity compared with placebo regarding AEs of grade 3 or higher (OR, 1.3; 95% CI, 1.0–1.7) and serious AEs (OR, 1.3; 95% CI, 0.99–1.6). When compared with darolutamide, enzalutamide caused significantly higher toxicity in terms of any AEs (OR, 2.3; 95% CI,1.5–3.7) and AEs of grade 3 or higher (OR, 1.6; 95% CI, 1.1–2.2), apalutamide caused significantly more AEs of grade 3 or higher (OR, 1.9; 95% CI, 1.4–2.7) and serious AEs (OR, 1.9; 95% CI, 1.3–2.8). Subgroup analysis showed that SGARAs as a group significantly improved OS in ECOG=1 population, although insignificant results were found in these patients from included studies.

Conclusions

SGARAs combined with ADT significantly improved OS when compared with ADT alone in high-risk nmCRPC patients. Darolutamide may not only provide best OS but also have the most favorable safety profile among the included SGARAs in high-risk nmCRPC patients.

Nomogram Incorporating Contrast-Enhanced Ultrasonography Predicting Time to the Development of Castration-Resistant Prostate Cancer

Background

It is valuable to predict the time to the development of castration-resistant prostate cancer (CRPC) in patients with advanced prostate cancer (PCa). This study aimed to build and validate a nomogram incorporating the clinicopathologic characteristics and the parameters of contrast-enhanced ultrasonography (CEUS) to predict the time to CRPC after androgen deprivation therapy (ADT).

Methods

Patients with PCa were divided into the training (n = 183) and validation cohorts (n = 37) for nomogram construction and validation. The clinicopathologic characteristics and CEUS parameters were analyzed to determine the independent prognosis factors and serve as the basis of the nomogram to estimate the risk of 1-, 2-, and 3-year progress to CRPC.

Results

T stage, distant metastasis, Gleason score, area under the curve (AUC), prostate-specific antigen (PSA) nadir, and time to PSA nadir were the independent predictors of CRPC (all P < 0.05). Three nomograms were built to predict the time to CRPC. Owing to the inclusion of CEUS parameter, the discrimination of the established nomogram (C-index: 0.825 and 0.797 for training and validation datasets) was improved compared with the traditional prediction model (C-index: 0.825 and 0.797), and when it excluded posttreatment PSA, it still obtained an acceptable discrimination (C-index: 0.825 and 0.797).

Conclusions

The established nomogram including regular prognostic indicators and CEUS obtained an improved accuracy for the prediction of the time to CRPC. It was also applicable for early prediction of CRPC when it excluded posttreatment PSA, which might be helpful for individualized diagnosis and treatment.

Stereotactic Re-Irradiation for Local Recurrence after Radical Prostatectomy and Radiation Therapy: A Retrospective Multicenter Study

Prostate cancer recurrence in patients previously treated with radical prostatectomy and radiation therapy is challenging. Re-irradiation could be an option, but data regarding efficacy and safety are lacking. We retrospectively evaluated salvage re-irradiation for local recurrence after prostatectomy and external beam radiation therapy. We collected data from 48 patients who underwent salvage reirradiation with stereotactic radiation therapy for local prostate cancer recurrence in the prostatic bed at four French centers. Fifteen patients (31%) were on androgen deprivation therapy during stereotactic radiotherapy. Biochemical response and relapse-free survival were analyzed, and post-treatment toxicities were assessed according to the Common Terminology of Adverse Events criteria. Five patients had grade 3 late bladder toxicity (cystitis), three had grade 3 late incontinence, and one had grade 3 late chronic pain. At three months, 83% of patients had a positive biochemical response. The median follow-up was 22 months. At the end of the follow-up, 21 patients (43%) had a biochemical relapse. The median time to biologic relapse was 27 months. The biochemical relapse rates at 1 and 2 years were 80% and 52%, respectively. In conclusion, salvage re-irradiation for recurrent prostate cancer in the prostate bed may generate significant toxicity rates, and a prospective study with appropriate patient selection is needed to evaluate its effectiveness.

Treatment and trials in non-metastatic castration-resistant prostate cancer

Metastatic prostate cancer is associated with considerable morbidity and mortality. Standard treatment for non-metastatic prostate cancer, to prevent metastatic progression, is androgen deprivation therapy (ADT); however, many patients will eventually develop castration-resistant prostate cancer (CRPC), which can prove challenging to treat. Between the stages of non-metastatic androgen-sensitive disease and metastatic CRPC is an intermediate disease state that has been termed non-metastatic CRPC (nmCRPC), which is a heterogeneous, man-made disease stage that occurs after a patient who has no radiological evidence of metastasis shows evidence of cancer progression even after ADT. Awareness of nmCRPC has risen owing to an increased use of ADT and its eventual failure. Men with nmCRPC are at a high risk of progression to mCRPC, with historically few options to halt this process. However, in the past two decades, multiple therapies have been investigated for the treatment of nmCRPC, including endothelin receptor antagonists and bone-targeted therapies, but none has changed the standard of care. In the past decade, the efficacy of androgen receptor pathway-targeting modalities has been investigated. Three novel nonsteroidal antiandrogen agents for treating high-risk nmCRPC have been investigated; the PROSPER, SPARTAN and ARAMIS trials were phase III, randomized, placebo-controlled clinical trials that investigated the efficacy and safety of enzalutamide, apalutamide and darolutamide, respectively. All three therapeutics showed statistically significant improvements in metastasis-free survival, progression to antineoplastic therapy was lengthened and at final analysis, overall survival was significantly improved. The comparative efficacy and safety of all three agents has not yet been investigated in a comprehensive clinical trial, but approval of these medications by the FDA and other regulatory agencies means that providers now have three effective therapeutic options to augment ADT for patients with nmCRPC.

Hong Kong Urological Association-Hong Kong Society of Uro-Oncology consensus statements on the management of advanced prostate cancer-2019 Updates

BACKGROUND

To update the Hong Kong Urological Association-Hong Kong Society of Uro-Oncology consensus statements on the management of advanced prostate cancer, the same panelists as in the previous consensus panel held a series of meetings to discuss updated clinical evidence and experiences.

METHODS

The previous consensus statements were retained, deleted, or revised, and new statements were added. At the final meeting, all statements were reviewed and amended as appropriate, followed by panel voting.

RESULTS

There were significant changes and additions to the previous consensus statements, primarily driven by the advances in androgen receptor signaling inhibitors, treatment sequencing in metastatic castration-resistant prostate cancer, and increasing recognition of oligometastatic prostate cancer since the introduction of prostate-specific membrane antigen positron emission tomography. In this update, a total of 59 consensus statements were accepted and established.

CONCLUSIONS

The consensus panel updated consensus statements on the management of advanced prostate cancer, aiming to allow physicians in the region to keep abreast of the recent evidence on optimal clinical practices.

Genome-wide Expression Analysis Identifies the Association between SEC14L2 and Castration-resistant Prostate Cancer Survival

Background: Mechanism of castration-resistant prostate cancer (CRPC) is still unclear. Our objective is to investigate the association between genes expression and CRPC through the genome-wide approach and functional researches.

Methods: Differentially expressed genes (DEGs) between PCa and CRPC tissues were identified using expression profile obtained from Gene Expression Omnibus database (GEO). Survival analysis was performed using online database Gene Expression Profiling Interactive Analysis (GEPIA). Oncomine database was further used to explore the relationship between DEGs expression levels with clinical parameters. After in silico study, SEC14L2-knockdown CRPC cells and normal prostatic epithelial cells were used for in vitro study to verify its biological functions.

Results: A total of 3 consistently changed DEGs (SEC14L2, DMD, SEL1L) were identified correlating with CRPC after cross validation in three independent datasets. Low expression of SEC14L2 was associated with poorer disease-free survival and higher Gleason score than normal/high expression of SEC14L2. SEC14L2 knockdown promoted cell proliferation, migration, invasion as well as cell cycle progression in CRPC cells (all P<0.05) while no significant effects were observed in normal prostatic epithelial cells.

Conclusions: Low expression of SEC14L2 was significantly associated with CRPC, and correlated with PCa aggressiveness and poorer prognosis. SEC14L2 might be a potential biomarker or drug target for CRPC.

Imaging for Metastasis in Prostate Cancer: A Review of the Literature

Background: Initial staging and assessment of treatment activity in metastatic prostate cancer (PCa) patients is controversial. Indications for the various available imaging modalities are not well-established due to rapid advancements in imaging and treatment.

Methods: We conducted a critical literature review of the main imaging abnormalities that suggest a diagnosis of metastasis in localized and locally advanced PCa or in cases of biological relapse. We also assessed the role of the various imaging modalities available in routine clinical practice for the detection of metastases and response to treatment in metastatic PCa patients.

Results: In published clinical trials, the most commonly used imaging modalities for the detection and evaluation of therapeutic response are bone scan, abdominopelvic computed tomography (CT), and pelvic and bone magnetic resonance imaging (MRI). For the detection and follow-up of metastases during treatment, modern imaging techniques i.e., choline-positron emission tomography (PET), fluciclovine-PET, or Prostate-specific membrane antigen (PSMA)-PET provide better sensitivity and specificity. This is particularly the case of fluciclovine-PET and PSMA-PET in cases of biochemical recurrence with low values of prostate specific antigen.

Conclusions: In routine clinical practice, conventional imaging still have a role, and communication between imagers and clinicians should be encouraged. Present and future clinical trials should use modern imaging methods to clarify their usage.

NOTCH signaling pathway and non-coding RNAs in cancer

Malignant tumors, known as cancer, seriously threaten human life and health. Cancer has the characteristics of abnormal cell differentiation, proliferation, invasion and metastasis. As a result, cancer often accompanied by poor prognosis and a lower survival rate. Notch signaling pathway is a highly conserved system in many multicellular organisms, and which has been proved to play a biological role in many cancers. In recent years, increasing evidence has shown that non-coding RNA can not only activate or inhibit NOTCH pathway, but also regulate the occurrence and development of cancer through NOTCH pathway. Therefore, we focus on the cancer-NOTCH-non-coding RNA axis in this review, and provide new ideas for cancer therapy.

Perspectives on the current and emerging chemical androgen receptor antagonists for the treatment of prostate cancer

INTRODUCTION

 Prostate cancer is the most common cancer in men. Regardless of the initial treatment of localized disease, almost all patients develop castration resistant prostate cancer (CRPC). A better understanding of the molecular mechanisms behind castration resistance has led to the approval of novel oral androgen receptor (AR) antagonists, such as enzalutamide and apalutamide. Indeed, research has accelerated with numerous agents being studied for the management of CRPC. Areas covered: Herein, the authors present currently used and emerging AR antagonists for the treatment of CRPC. Emerging agents include darolutamide, EZN-4176, AZD-3514, and AZD-5312, apatorsen, galeterone, ODM-2014, TRC-253, BMS-641988, and proxalutamide. Expert opinion: Further understanding of the mechanisms leading to castration resistance in prostate cancer can reveal potential targets for the development of novel AR antagonists. Current novel agents are associated with modest clinical and survival benefit, while acquired resistance and safety issues are under continuous evaluation. The combination of AR antagonists used and ideal sequencing strategies are key tasks ahead, along with the investigation of molecular biomarkers for future personalized targeted therapies. In the future, the challenge will be to determine an AR antagonist with the best combination of outcome and tolerability.