Androgen Blockade Research Articles

Androgen blockage impairs proliferation and function of Sertoli cells via Wee1 and Lfng

BackgroundAndrogens are essential hormones for testicular development and the maintenance of male fertility. Environmental factors, stress, aging, and psychological conditions can disrupt androgen production, impacting the androgen signaling pathway and consequently spermatogenesis. Within the testes, testosterone is produced by Leydig cells and acts on Sertoli cells by activating the androgen receptor (AR), which then translocates to the nucleus to function as a transcription factor. Despite clinical correlations between low testosterone levels and diminished sperm quality, the precise mechanism remains unclear.MethodsThis study explores the hypothesis that reduced androgen levels impair Sertoli cell function by disrupting AR transcriptional regulation. Using an androgen blockade model with enzalutamide, we investigated the impact of low androgen levels on AR target genes in Sertoli cells through ChIP-seq and RNA-seq assays.ResultsOur results reveal that androgen blockage increases AR enrichment on the promoter region of Wee1, promoting Wee1 expression, while decreasing binding to the promoter region of Lfng, inhibiting its expression. Increased WEE1 protein inhibits Sertoli cell proliferation, whereas reduced LFNG affects Notch modification, leading to decreased production of glial cell line-derived neurotrophic factor (GDNF), a key growth factor for spermatogonial stem cell self-renewal.ConclusionsThese findings provide new insights into the molecular mechanisms by which low androgen levels interfere with Sertoli cell functions, offering novel perspectives for the clinical treatment of male reproductive disorders.

Effect of deep testosterone reduction on the prognosis of metastatic prostate cancer with high-volume disease

ObjectiveThis study aims to investigate the correlation between serum testosterone levels after one month of treatment and prognosis in patients with high-volume disease metastatic prostate cancer (mPCa) who are undergoing combined androgen blockade therapy (CAB).MethodsThe clinical data of 199 patients with high-volume disease mPCa, diagnosed through biopsy pathology and imaging, were retrospectively analyzed from January 2010 to October 2022 in the Department of Urology at the First Affiliated Hospital of Xinjiang Medical University. Among these patients, 111 cases had a deep reduction in serum testosterone (< 0.7 nmol/l) after one month of treatment, while 88 cases did not achieve a deep reduction (≥ 0.7 nmol/l). The study utilized the Kaplan–Meier method to plot survival curves and employed the multifactor COX regression model to analyze independent risk factors. The risk factors with a significance level of P < 0.05 in the multivariate analysis were included in the nomogram prediction model. The accuracy of the model was assessed using the ROC curve and the calibration curve, while the net benefit for patients was evaluated through the decision curve analysis (DCA).ResultsThe group that achieved deep testosterone reduction(DTR) had a higher proportion of PSA < 0.2 ng/ml and a greater PSA decline rate after six months of treatment (P < 0.05). The group that achieved DTR and the group that did not achieve DTR had a progression to castration resistant prostate cancer(CRPC) time of 17.93 ± 6.68 months and 13.43 ± 6.12 months, respectively (P < 0.001). The median progression-free survival time for the 2 groups were 18 months and 12 months, respectively (P < 0.001). The median overall survival times were 57 months and 32 months, respectively (P < 0.001). The median progression-free survival times were 18, 15, and 10 months for the group that achieved DTR within 1 month, the group that achieved DTR beyond 1 month but within 1 year, and the group that did not achieve DTR within 1 year, respectively (P < 0.001), and the median survival times were 57, 45, and 26 months, respectively (P < 0.001). COX multivariate analysis revealed that a testosterone level of ≥ 0.7 nmol/l at 1 month of treatment is an independent risk factor for the progression to CRPC and prognosis in patients with high-volume disease mPCa (P < 0.05). The risk of death in patients with a testosterone level of ≥ 0.7 nmol/l at 1 month of treatment was 2.087 times higher than that of patients with a level of < 0.7 nmol/l (P < 0.05). A nomogram prediction model was developed using independent risk factors, with the area under the ROC curve (AUC) for progression-free survival (PFS) at 12, 15, 18, and 21 months being 0.788, 0.772, 0.760, and 0.739, respectively. For 3 and 5 years, the AUCs for overall survival (OS) were 0.691 and 0.624. The calibration curve demonstrated good consistency between the model’s predicted values and the actual outcomes.ConclusionPatients with high-volume disease mPCa who receive CAB treatment may experience extended progression-free survival and overall survival if their serum testosterone levels are below 0.7 nmol/l after one month of treatment. The longer it takes to achieve DTR, the worse the patient’s prognosis may be. The nomogram prediction model developed in this study demonstrates good predictive ability in assessing the progression and prognosis of high-volume disease mPCa.

Extra-Skeletal Osteosarcoma of the Prostate After Treated Prostatic Acinar Adenocarcinoma: A Case Report and Review of the Literature.

Extra-skeletal osteosarcoma is a rare form of malignant soft tissue sarcoma. Its occurrence in the prostate gland is particularly uncommon. In this case report, we present a patient diagnosed with osteosarcoma arising within the prostatic gland. A 58-year-old man was initially diagnosed with Gleason 8 prostate acinar adenocarcinoma following a transurethral resection (TUR) of the prostate. This diagnosis was accompanied by locoregional involvement and multiple bone metastases. The patient underwent a treatment regimen including complete androgen blockade, chemotherapy, greenlight laser prostate vaporization, and palliative radiotherapy. After treatment, he achieved a complete biochemical response, and his bone metastases remained stable. However, at 16 months post-diagnosis, clinical follow-up by means of radiological examinations revealed an increase in the size of the prostatic lesion, along with additional infiltration of the tumor into the rectum and bladder walls. Remarkably, a mesenchymal tumor proliferation with intratumor calcifications was observed. A subsequent TUR biopsy of the prostate showed a malignant tumor spindle and ovoid cell proliferation with high-grade nuclear atypia, necrosis, and islets of osteoid formation, leading to a final diagnosis of high-grade prostatic extra-skeletal osteosarcoma. Despite undergoing chemotherapy, the patient's condition progressed with the development of pulmonary and liver metastases, culminating in his demise.

A retrospective study of prognostic factors and prostate-specific antigen dynamics in Japanese patients with metastatic hormone-sensitive prostate cancer who received combined androgen blockade therapy with bicalutamide.

This retrospective observational study explored the therapeutic potential of combined androgen blockade (CAB) with bicalutamide (Bic-CAB) as an initial treatment for metastatic hormone-sensitive prostate cancer (mHSPC) in Japan. The electronic health records of 159 patients with mHSPC from three Japanese institutions who received initial treatment with Bic-CAB between 2007 and 2017 were analyzed. The time to prostate-specific antigen (PSA) progression, duration of Bic-CAB treatment, and overall survival (OS), with various definitions for PSA progression, were assessed. A multivariate Cox proportional hazards model was constructed using clinical parameters to predict time to the end of Bic-CAB treatment and OS. The median observation period was 46.4months, and the median age of patients at diagnosis was 71years. A total of 46.5% patients experienced PSA progression with a median survival duration of 29months (according to Prostate Cancer Clinical Trials Working Group 3 criteria), and 49.1% patients achieved a PSA nadir < 0.2ng/mL in a median time of 4.7months. When stratified by PSA nadir and PSA change, patients at low risk for disease progression with a small PSA change due to low initial PSA had a 5-year OS of 100% and a 10-year OS of 75%. The OS during the observation period was 72.9months. These findings highlight the potential effect of Bic-CAB in patients with mHSPC who were at low risk for disease progression. Initial treatment with Bic-CAB and adjusting treatment early based on PSA dynamics may be a reasonable treatment plan for these patients.

A randomized phase II trial on the addition of dutasteride to combined androgen blockade therapy versus combined androgen blockade therapy alone in patients with advanced or metastatic salivary duct carcinoma – the DUCT study protocol

BackgroundSalivary duct carcinoma (SDC) is a rare and aggressive subtype of salivary gland cancer, frequently associated with incurable recurrences and distant metastases (R/M). Proliferation of SDC relies on androgen receptor (AR) signalling, prompting the use of combined androgen blockade (CAB, i.e., luteinizing hormone-releasing hormone agonist and/or AR antagonists) to R/M SDC patients. However, only a subset of patients benefits from such treatments. We have shown that response to CAB is associated with steroid 5α-reductase 1 (SRD5A1) mRNA expression. SRD5A1 catalyses the intracellular conversion of testosterone into the more potent AR-agonist dihydrotestosterone. This conversion can be inhibited by dutasteride, a potent SRD5A1-inhibitor, which is currently prescribed for benign prostatic hyperplasia. We hypothesize that repurposing dutasteride to target AR signalling in SDC could enhance therapeutic response and clinical outcome in SDC patients.MethodsThis prospective, open-label, randomized controlled phase II clinical trial, is designed to investigate whether dutasteride as an adjunct drug to CAB improves response rate and clinical outcome in patients with AR-positive R/M SDC. Patients are divided in two cohorts based on their prior systemic treatments. In cohort A, CAB-naïve patients (n = 74) will be randomly assigned to either a control arm (Arm 1) receiving CAB (goserelin 10.8 mg/3m and bicalutamide 50 mg/OD) or an experimental arm (Arm 2) where dutasteride (0.5 mg/OD) is added to the CAB regimen. In cohort B, patients with disease progression after adjuvant or first-line palliative CAB therapy (max. n = 24) will receive goserelin, bicalutamide, and dutasteride to assess whether the addition of dutasteride can overcome therapy resistance. The primary endpoints are the objective response rate and duration of response. Secondary endpoints are progression-free survival, overall survival, clinical benefit rate, quality of life, and safety. Translational research will be performed to explore molecular target expression differences and their correlation with clinical outcome.DiscussionThe DUCT study addresses an unmet medical need by investigating the repurposing of dutasteride to enhance treatment response and improve clinical outcome for patients with R/M SDC, especially those with limited alternative treatment options, such as HER2-negative cases. By repurposing a registered low-cost drug, this trial’s findings could be readily applied into clinical practice.Trial registrationClinicaltrials.gov Identifier: NCT05513365. Date of registration: August 24, 2022.Protocol versionCurrent protocol version 4.0, February 21, 2024.

Changes in the treatment landscape of metastatic hormone-sensitive prostate cancer: A multicenter study.

118 Background: A multicenter database was utilized to examine the current treatment landscape and clinical outcomes among patients with metastatic hormone-sensitive prostate cancer (mHSPC) following approval of upfront androgen receptor signaling inhibitors (ARSIs). Methods: We retrospectively analyzed patients with mHSPC who commenced treatment between February 2018 and June 2023. The Kaplan–Meier method was used to assess oncological outcomes, including time to castration-resistant prostate cancer (CRPC), progression-free survival 2 (PFS2, duration from initial treatment to tumor progression during second-line treatment), cancer-specific survival (CSS), and overall survival (OS). Cox regression analyses were performed to determine the impact of treatment choices on oncological outcomes. In addition, the incidence rate of adverse events was assessed. Results: In total, 829 patients were analyzed; 42.5% received ARSIs with androgen deprivation therapy (ADT), 44.0% received combined androgen blockade (CAB), and 13.5% received ADT alone. Analysis of annual treatment choice trends revealed an increasing preference for ARSIs with ADT. Kaplan–Meier curves and multivariate Cox regression analyses indicated higher rates of CRPC and shorter PFS2 in patients treated with CAB versus ARSIs with ADT. By contrast, CSS and OS were not significantly different between the ARSI with ADT group and the CAB group. Grade 3–4 adverse events occurred in 1.9% of patients receiving CAB and 6.0% of those receiving ARSIs with ADT. Conclusions: For patients with mHSPC, initial treatment with ARSIs in combination with ADT resulted in a longer time to CRPC and longer PFS2 compared to CAB. Although CAB and ADT alone were associated with fewer adverse events, ARSIs with ADT should be considered a first-line treatment option given its superior oncological outcomes.

Changes in the treatment landscape of metastatic hormone-sensitive prostate cancer following approval of upfront androgen receptor signaling inhibitors: A multicenter study.

A multicenter database was utilized to examine the current treatment landscape and clinical outcomes among patients with metastatic hormone-sensitive prostate cancer (mHSPC) following approval of upfront androgen receptor signaling inhibitors (ARSIs). We retrospectively analyzed patients with mHSPC who commenced treatment between February 2018 and June 2023. The Kaplan-Meier method was used to assess oncological outcomes, including time to castration-resistant prostate cancer (CRPC), progression-free survival 2 (PFS2, duration from initial treatment to tumor progression during second-line treatment), cancer-specific survival (CSS), and overall survival (OS). Cox regression analyses were performed to determine the impact of treatment choices on oncological outcomes. In addition, the incidence rate of adverse events was assessed. In total, 829 patients were analyzed; 42.5% received ARSIs with androgen deprivation therapy (ADT), 44.0% received combined androgen blockade (CAB), and 13.5% received ADT alone. Kaplan-Meier curves and multivariate Cox regression analyses indicated higher rates of CRPC and shorter PFS2 in patients treated with CAB versus ARSIs with ADT. By contrast, CSS and OS were not significantly different between the ARSI with ADT group and the CAB group. Grades 3-4 adverse events occurred in 1.9% of patients receiving CAB and 6.0% of those receiving ARSIs with ADT. Initial treatment with ARSIs in combination with ADT resulted in a longer time to CRPC and longer PFS2 compared to CAB. Although CAB and ADT alone were associated with fewer adverse events, ARSIs with ADT should be considered a first-line treatment option given its superior oncological outcomes.

Single-cell analysis of treatment-resistant prostate cancer: Implications of cell state changes for cell surface antigen–targeted therapies

Targeting cell surface molecules using radioligand and antibody-based therapies has yielded considerable success across cancers. However, it remains unclear how the expression of putative lineage markers, particularly cell surface molecules, varies in the process of lineage plasticity, wherein tumor cells alter their identity and acquire new oncogenic properties. A notable example of lineage plasticity is the transformation of prostate adenocarcinoma (PRAD) to neuroendocrine prostate cancer (NEPC)-a growing resistance mechanism that results in the loss of responsiveness to androgen blockade and portends dismal patient survival. To understand how lineage markers vary across the evolution of lineage plasticity in prostate cancer, we applied single-cell analyses to 21 human prostate tumor biopsies and two genetically engineered mouse models, together with tissue microarray analysis on 131 tumor samples. Not only did we observe a higher degree of phenotypic heterogeneity in castrate-resistant PRAD and NEPC than previously anticipated but also found that the expression of molecules targeted therapeutically, namely PSMA, STEAP1, STEAP2, TROP2, CEACAM5, and DLL3, varied within a subset of gene-regulatory networks (GRNs). We also noted that NEPC and small cell lung cancer subtypes shared a set of GRNs, indicative of conserved biologic pathways that may be exploited therapeutically across tumor types. While this extreme level of transcriptional heterogeneity, particularly in cell surface marker expression, may mitigate the durability of clinical responses to current and future antigen-directed therapies, its delineation may yield signatures for patient selection in clinical trials, potentially across distinct cancer types.

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

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

Health-related quality of life (HRQOL) results from PRESTO (AFT-19), a phase 3 randomized trial of intensification of androgen blockade in patients with high-risk biochemically relapsed castration sensitive prostate cancer.

Health-related quality of life (HRQOL) results from PRESTO (AFT-19), a phase 3 randomized trial of intensification of androgen blockade in patients with high-risk biochemically relapsed castration sensitive prostate cancer.

A Case of Metastatic Prostate Cancer with Neuroendocrine Differentiation with Long-Term Survival after Multidisciplinary Therapy

A 74-year-old man visited the urology clinic with the chief complaint of urinary retention in December 2014. Serum level of initial prostate specific antigen (PSA) was 50 ng/ml and he was diagnosed with Gleason Score 4＋4 prostate adenocarcinoma with regional lymphadenopathy (cT3aN1M0). PSA level had declined after the treatment with combined androgen blockade. In November 2018, he was diagnosed with castration resistant prostate cancer (CRPC) as local progression was detected by computed tomography (CT) while PSA level did not increase. Since local symptoms worsened, resulting in repeated hematuria after the treatment with enzalutamide, palliative radiation therapy to the prostate (45 Gy) was performed. Five months later, follow-up CT showed multiple metastasis in bilateral lung and left testicle. Serum level of neuron-specific enolase (NSE) was 24.4 ng/ml without an elevated in serum PSA level. He received rebiopsy of the prostate, but no malignant findings were observed. Consequently, bilateral orchiectomy was performed for diagnosis of left testicular tumor. Pathological examination revealed metastasis of neuroendocrine prostate cancer (NEPC). Chemotherapy using cisplatin and irinotecan was administered after orchiectomy. Complete response of lung lesions was achieved and serum level of NSE decreased within normal range. No recurrence has been confirmed for 4 years after the completion of chemotherapy.

Maximal androgen blockade therapy (MAB) for prostate cancer (PC) and risk of bone fractures: A systematic literature review and meta-analysis.

Maximal androgen blockade therapy (MAB) for prostate cancer (PC) and risk of bone fractures: A systematic literature review and meta-analysis.

EORTC 2238 "De-Escalate": a pragmatic trial to revisit intermittent androgen deprivation therapy in the era of new androgen receptor pathway inhibitors.

The landscape of treating metastatic prostate cancer has evolved with the addition of Androgen Receptor pathway inhibitor (ARPI) to Androgen Deprivation Therapy (ADT), significantly improving survival rates. However, prolonged use of these therapies introduces notable side effects, prompting a need to revisit intermittent treatment duration. The EORTC 2238 De-Escalate trial is a pragmatic trial seeking to reassess the role of intermittent therapy in patients undergoing maximal androgen blockade (MAB) for metastatic hormone naïve prostate cancer (mHNPC), i.e., the combination of ADT with an ARPI, with the aims of reducing side effects, enhancing Quality of Life (QoL) and optimizing resource usage, while maintaining oncological benefits.

Hormonal Therapy and Radiation Therapy in Prostate Cancer: 5-Year Outcomes From a Trial Evaluating Combined Androgen Blockade With 5-Alpha Reductase Inhibitors as an Alternative to Gonadotropin Releasing Hormone Agonists

BackgroundWe previously reported that for men undergoing combined androgen deprivation therapy (ADT) and radiation therapy (RT) for prostate cancer, substitution of LHRH-agonists with 5-α- reductase inhibitors (5-ARIs) led to improved preservation of 6-month hormonal quality of life (hQOL). With longer term follow-up, we evaluated disease control. MethodsIn this non-randomized trial, men with unfavorable intermediate or high-risk prostate cancer, aged ≥70 years or with Charlson Comorbidity Index ≥2, were treated with RT (78-79.2 Gy in 39-44 fractions) and either oral ADT (oADT; 5-ARI with antiandrogen) or standard of care ADT (SOC; leuprolide with antiandrogen) for up to 28 months. The primary endpoint was EPIC hQOL; secondary endpoints included biochemical control and survival as well as changes in cholesterol and hemoglobin levels. ResultsBetween 2011 and 2018, 70 men were enrolled (40 in oADT; 30 in SOC). Median follow-up was 65 months [IQR 36-94]. Five-year freedom from biochemical failure for oADT and SOC was 89% versus 86%, disease free survival was 62% versus 69%, cancer-specific survival was 100% versus 96%, and overall survival was 70% versus 81% (all P>.1). Testosterone (2 mo through 3 yr) and hemoglobin levels (2 mo through 2 yr) were higher, and cholesterol levels (1 yr) were lower in the oADT groups (all P < .05). ConclusionsIn this non-randomized study, men treated with combined RT and oADT had better preservation of hQOL and comparable 5-year disease outcomes to men treated with SOC. Eugonadal testosterone with this approach may yield measurable benefits in cholesterol and hemoglobin levels.

Genomic profiling and clinical utility of circulating tumor DNA in metastatic prostate cancer: SCRUM-Japan MONSTAR SCREEN project

BackgroundCirculating tumor DNA (ctDNA) testing has emerged as a novel tool for cancer precision medicine. This study investigated the genomic profiling and clinical utility of ctDNA in metastatic prostate cancer.MethodsThis is a nation-wide prospective observational study. Patients treated with systemic treatment for metastatic castration-sensitive prostate cancer (mCSPC) and metastatic castration-resistant prostate cancer (mCRPC) were included. ctDNA was analyzed using FoundationOne Liquid®CDx at enrollment. In a subset of patients, ctDNA after disease progression and tissue prior to the initiation of treatment were examined using FoundationOne Liquid®CDx and FoundationOne®CDx, respectively.ResultsThe frequency of AR alterations and homologous recombination repair (HRR) defect was higher in mCRPC compared with mCSPC. Tumor mutational burden was correlated between tissue and ctDNA at pre-treatment, as well as ctDNA between at pre-treatment and at post-treatment. Patients with HRR defect were associated with shorter time to castration resistance in androgen deprivation therapy/combined androgen blockade, but not in androgen receptor pathway inhibitor, compared with patients without HRR defect in mCSPC. Time to treatment failure in patients with AR amplification or AR mutation was shorter compared with patients without AR alterations in mCRPC.ConclusionsThis study revealed valuable findings for the clinical care of metastatic prostate cancer. Especially, predictive factors such as HRR defect in mCSPC should be validated in the future.

Safety of Docetaxel in a Patient with Metastatic Castration-Resistant Prostate Cancer After Kidney Transplantation: A Case Report

There are limitations in treating advanced prostate cancer (PC), especially castration-resistant (CR) cases, in renal transplant recipients (RTRs). We describe the case of RTR with metastatic CRPC (mCRPC) treated with docetaxel. A 60-year-old man with end-stage renal disease due to autosomal-dominant polycystic kidney disease (ADPKD) underwent living-related kidney transplantation. A year later, he was diagnosed with PC (prostate-specific antigen level: 998 ng/mL). Prostate biopsy revealed prostatic adenocarcinoma with a Gleason score of 4 + 4 = 8. Radiographic examination revealed seminal vesicle invasion and multiple bone and lymph node metastases. Combined androgen blockade therapy was initiated; however, the patient was diagnosed with CRPC 6 months later. Triweekly docetaxel therapy was administered 28 months after diagnosis. The patient successfully completed 7 cycles of this therapy without major adverse events. However, after the 7th cycle, he developed a high fever caused by an infection of ADPKD-associated renal cysts. Therefore, docetaxel was discontinued, and enzalutamide was started, followed by abiraterone, but without any effect. We then introduced cabazitaxel but discontinued it because of hepatic dysfunction. Hence, the patient underwent a docetaxel rechallenge. He was administered the PEGylated form of the recombinant human granulocyte colony-stimulating factor for neutropenia prophylaxis. After 6 cycles of rechallenge docetaxel therapy, the patient accidentally fell, resulting in a cervical spine fracture and subsequent death due to respiratory failure. Docetaxel can be safely delivered to patients with CRPC after renal transplantation who are taking oral immunosuppressants. It can be a good treatment option for them.

Abstract 5651: Personalized transcriptomic profiling for advanced prostate cancer: Guiding second-generation hormonal drug selection

Abstract Introduction: Second-generation hormonal drugs have demonstrated significant efficacy in extending the survival of patients with advanced prostate cancer. These drugs operate through two distinct molecular mechanisms: inhibition of androgen biosynthesis and blockade of the androgen receptor. However, due to concerns of side effects, concurrent usage of multiple drugs is not recommended. A notable challenge is the eventual development of drug resistance, rendering all second-generation hormonal therapies ineffective. Currently, there is a lack of guidelines for helping patients choose the most suitable drug. In the context of pharmacogenomics, genetic differences can influence drug susceptibility and efficacy, with variations in genomic sequences and regulatory mechanisms impacting drug response at the transcriptional and translational levels. Considered the rapid processing capabilities of Affymetrix transcriptomic microarrays, we hypothesized that distinct gene signatures in patients who respond well or poorly to second-generation hormonal drugs could be identified and could act as a companion diagnostic tool. Methods: We enrolled 180 advanced prostate cancer patients, who fulfilled Taiwan national health insurance criteria of using second-generation hormonal drugs, from seven medical centers or regional hospitals in Taiwan at 3 time points: prior to drug administration, 3 months after treatment started and drug resistance developed. The RNA expression data and clinical parameters were analyzed, and classification models were built using IPA and R. Good or poor responders were defined by 3-month prostate-specific antigen (PSA) lowered by 90 percent. Results:: Differential expression and enrichment analyses post-treatment highlighted the activation of NF-kappa B signaling and various immune cell pathways. Notably, pathways related to primary immunodeficiency and IL-17 became prominent following the development of drug resistance. At the initial stages, distinct alterations in cell cycle pathways, particularly G1/S and G2/M, were observed between good and poor responders. This was elucidated through principal component analysis and subsequent dbscan clustering. To further distinguish between these responder groups, we utilized an integrative approach for feature selection, combining support vector machine, random forest classifier, and lasso regression. Despite the innovative approach, the model's error rate stood at approximately 15%, attributed mainly to the limited number of cases. Conclusion: Our study highlights the potential of using transcriptomic analysis to predict responses to second-generation hormonal drugs in advanced prostate cancer, paving the way for personalized treatment strategies. However, the need for larger cohort studies is evident to refine these predictive models and enhance their accuracy. Citation Format: Li-Hsin Chang, Hao-Han Chang, Xin-Yi Lin, Shu-Chi Wang, Chih-Pin Chuu, Deng-Neng Chen, Shu-Pin Huang, Chia-Yang Li. Personalized transcriptomic profiling for advanced prostate cancer: Guiding second-generation hormonal drug selection [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5651.

Determination of enzalutamide long-term safety and efficacy for castration-resistant prostate cancer patients after combined anti-androgen blockade followed by alternative anti-androgen therapy: a multicenter prospective DELC study.

Alternative anti-androgen therapy has been widely used as a first-line treatment for castration-resistant prostate cancer, and it may affect treatment outcome of subsequent agents targeting the androgen receptor axis. We conducted the prospective observational DELC (Determination of Enzalutamide Long-term safety and efficacy for Castration-resistant prostate cancer patients after combined anti-androgen blockade followed by alternative anti-androgen therapy) study to evaluate the efficacy of enzalutamide in patients with castration-resistant prostate cancer who underwent prior combined androgen blockade with bicalutamide and then alternative anti-androgen therapy with flutamide. The DELC study enrolled 163 Japanese patients with castration-resistant prostate cancer who underwent alternative anti-androgen therapy with flutamide following failure of initial combined androgen blockade with bicalutamide in multiple institutions between January 2016 and March 2019. Primary endpoint was overall survival. Administration of enzalutamide was started at 160mg orally once daily in all patients. The rate of decline of prostate-specific antigen by 50% or more was 72.2%, and median overall survival was 42.05months. Multivariate analysis revealed that higher pretreatment serum levels of prostate-specific antigen (≥11.3ng/mL; P=0.004), neuron-specific enolase (P=0.014) and interleukin-6 (≥2.15pg/mL; P=0.004) were independent risk factors for overall survival. Fatigue (30.0%), constipation (19.6%) and appetite loss (17.8%) were the most common clinically relevant adverse events. The enzalutamide dose was not reduced in any patient under the age of 70, but adherence was decreased in those over 70. In the DELC study, the safety of enzalutamide was comparable to that in previous reports. Serum levels of neuron-specific enolase and interleukin-6 were suggested as prognostic factors for castration-resistant prostate cancer with potential clinical utility.

Optimal sequential therapy for metastatic castration-resistant prostate cancer after androgen receptor pathway inhibitors in the up-front era.

168 Background: The optimal sequential therapy for metastatic castration-resistant prostate cancer (mCRPC) following the use of up-front androgen receptor pathway inhibitors (ARPIs) for metastatic hormone-sensitive prostate cancer (mHSPC) is still unclear. Methods: A total of 220 patients who received systemic therapy for de novo mHSPC at Nagoya University Hospital and its affiliated institutions between 2014 and 2022 were included in the study. Patients who received up-front therapy with ARPI as first-line therapy for mHSPC, followed by ARPI as primary therapy for mCRPC were defined as the AA group, followed by docetaxel (DOC) as primary therapy for mCRPC were defined as the AD group. On the other hand, the vAA group was defined as patients who received androgen deprivation therapy alone or combined androgen blockade as “vintage” first-line therapy for mHSPC, followed by two consecutive ARPIs as sequential therapy for mCRPC, and the vAD group was defined as patients who received ARPI followed by DOC as sequential therapy for mCRPC. Patient characteristics and progression-free survival (PFS) of the second agent after the first ARPI were compared in each group. Results: We identified 14 patients in the AA group, 16 in the AD group, 84 in the vAA group, and 59 in the vAD group. There were no differences in patient background such as initial PSA, Gleason score, and metastatic burden between the groups, while patient age was lower in the AD and vAD groups compared to the AA and vAA groups. The PFS of the second agent in the AA group was significantly shorter than that in the vAA group (median, 6.8 vs. 1.9 months; hazard ratio [HR], 0.25; 95% confidence interval [CI], 0.25-0.87; p=0.017). In contrast, there was no significant difference in PFS of the second agent in the vAD and AD groups (median, 7.0 vs. 4.0 months; HR, 0.63; 95%CI, 0.29-1.34; p=0.235). Conclusions: The effect of each agent after ARPI therapy in the UP-FRONT era may be poorer than that in the VINTAGE era. In the setting after up-front ARPI, sequential therapy with DOC may be more appropriate than sequential therapy with ARPI.

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

To compare the effectiveness and safety of gonadotropin-releasing hormone (GnRH) antagonist monotherapy to combined androgen blockade (CAB) with a GnRH agonist and bicalutamide in patients with advanced hormone-sensitive prostate cancer (HSPC). The study was conducted as KYUCOG-1401 trial (UMIN000014243) and enrolled 200 patients who were randomly assigned to either group A (GnRH antagonist monotherapy followed by the addition of bicalutamide) or group B (CAB by a GnRH agonist and bicalutamide). The primary endpoint was PSA progression-free survival. The secondary endpoints were the time to CAB treatment failure, radiographic progression-free survival, overall survival, changes in serum parameters, including PSA, hormones, and bone and lipid metabolic markers, and adverse events. PSA progression-free survival was significantly longer in group B (hazard ratio [HR], 95% confidence interval [CI]; 1.40, 1.01-1.95, p = 0.041). The time to CAB treatment failure was slightly longer in group A (HR, 95% CI; 0.80, 0.59-1.08, p = 0.146). No significant differences were observed in radiographic progression-free survival or overall survival. The percentage of patients with serum testosterone that did not reach the castration level was higher at 60 weeks (p = 0.046) in group A. No significant differences were noted in the serum levels of bone metabolic or lipid markers between the two groups. An injection site reaction was more frequent in group A. The present results support the potential of CAB using a GnRH agonist and bicalutamide as a more effective treatment for advanced HSPC than GnRH antagonist monotherapy.