First-line Androgen Deprivation Therapy Research Articles

Enzalutamide Maintenance Following Docetaxel in Metastatic Castration-Naive Prostate Cancer: A Pilot Feasibility Study

Purpose: To assess the feasibility and short-term efficacy of maintenance enzalutamide following first-line docetaxel plus androgen deprivation therapy (ADT) in patients with high-volume, metastatic castration-naive prostate cancer (mCNPC).Materials and Methods: The present study included 38 consecutive patients with mCNPC who did not have disease progression with ADT plus docetaxel between October 2022 and October 2023. Patients received a switch maintenance therapy with enzalutamide until progression, unacceptable toxicity, or patient withdrawal. Endpoints included time to prostate-specific antigen (PSA) progression and safety.Results: Among the 38 patients, the median age was 68 years, and the most frequently observed metastatic site was bone (n=36), followed by lymph nodes (n=28), lung (n=8), and liver (n=1). The median duration of firstline docetaxel was 2.8 months (range, 2.7–5.0 months). At the time of commencing maintenance enzalutamide, the median PSA was 3.2 ng/mL (range, 0.01–258 ng/mL). Maintenance enzalutamide was generally welltolerated. A total of 11 patients (28%) discontinued enzalutamide, and the main reasons included adverse events (prolonged fatigue of grade 1 or 2, n=6), disease progression (n=3) and financial burdens (n=2). Median time to PSA progression was not reached, and 93% were PSA progression-free at 12 months.Conclusions: Maintenance enzalutamide is a feasible treatment option with potential clinical benefit for patients with high-volume mCNPC who were progression-free after first-line ADT+docetaxel.

PD16-06 EXAMINING TESTOSTERONE RECOVERY IN ANDROGEN DEPRIVATION THERAPY FOR PROSTATE CANCER

You have accessJournal of UrologyCME1 Apr 2023PD16-06 EXAMINING TESTOSTERONE RECOVERY IN ANDROGEN DEPRIVATION THERAPY FOR PROSTATE CANCER Mark A. Preston, Jessica R. Marden, Noam Kirson, Esmond Nwokeji, Raj Gandhi, Allison Briggs, Katherine Gaburo, Sarah Hanson, and Alicia K. Morgans Mark A. PrestonMark A. Preston More articles by this author , Jessica R. MardenJessica R. Marden More articles by this author , Noam KirsonNoam Kirson More articles by this author , Esmond NwokejiEsmond Nwokeji More articles by this author , Raj GandhiRaj Gandhi More articles by this author , Allison BriggsAllison Briggs More articles by this author , Katherine GaburoKatherine Gaburo More articles by this author , Sarah HansonSarah Hanson More articles by this author , and Alicia K. MorgansAlicia K. Morgans More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003271.06AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Androgen deprivation therapy (ADT) used in prostate cancer (PC) can delay testosterone (T) recovery (TR) after treatment cessation. Data are lacking on the clinical impact of prolonged TR. This real-world study examined clinical events among PC patients with and without TR after discontinuing injectable ADT. METHODS: A retrospective longitudinal cohort study was conducted using electronic medical records (Optum’s de-identified Market Clarity Data, 2010–2021). Eligible patients had a PC diagnosis, initiated first-line ADT monotherapy, and had ≥1 serum T level within 1 year of ADT discontinuation. Patients were classified as having TR (serum T >280 ng/dL) or no TR within 1 year of ADT discontinuation. Clinical outcomes examined included myocardial infarction, cerebrovascular accident, diabetes, depression, hot flashes, sexual dysfunction, and bone complications. The proportion of patients with events at 12 months were reported. Multivariate Cox proportional hazards models estimated hazard ratios (HRs) for TR vs non-TR cohorts, adjusting for demographics and baseline clinical events. RESULTS: 1553 patients were identified in the TR (n=390) and non-TR (n=1163) cohorts. Median age at ADT initiation was 70.3 years with 94.8% receiving a luteinizing hormone-releasing hormone agonist. Baseline median serum T was 254.0 ng/dL among patients with available data. During the 1-year post-ADT discontinuation, median serum T levels were 330.5 ng/dL for TR and 32.7 for non-TR cohorts. At 12 months post-discontinuation, a higher proportion of TR vs non-TR patients had sexual dysfunction, while lower proportions had new onset diabetes and depression (Table 1). Adjusted Cox analyses showed TR patients had a lower risk of diabetes (HR=0.47 [95% CI 0.27–0.79], p=0.005) vs the non-TR cohort and trended toward lower risk of depression (HR=0.58 [0.33–1.02], p=0.059) but a higher risk of sexual dysfunction (HR=1.33 [0.99–1.78], p=0.060). CONCLUSIONS: Patients with recovered serum T within 1 year of ADT discontinuation were less likely to experience diabetes. Trends showed a lower rate of depression and sexual dysfunction as potentially correlated with time to TR. Sexual dysfunction may have been higher among TR patients due to greater levels of sexual interest post ADT. Source of Funding: Myovant Sciences, Inc. in collaboration with Pfizer, Inc © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e491 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Mark A. Preston More articles by this author Jessica R. Marden More articles by this author Noam Kirson More articles by this author Esmond Nwokeji More articles by this author Raj Gandhi More articles by this author Allison Briggs More articles by this author Katherine Gaburo More articles by this author Sarah Hanson More articles by this author Alicia K. Morgans More articles by this author Expand All Advertisement PDF downloadLoading ...

Prognostic significance of nadir PSA value and time to nadir PSA in patients with metastatic castration-naive prostate cancer receiving first-line hormonotherapy.

The current study aimed to evaluate the effect of the time duration to reach the lowest prostate-specific antigen (PSA) from the onset of first-line hormonal treatment (time to nadir PSA, TTNpsa) on survival in castration-naive metastatic prostate cancer (CN-MPC) patients. Eighty patients who had PSA response >80% with first-line hormonal therapy (luteinizing hormone-releasing hormone, LH-RH analog +/- bicalutamide) were included in this study. Under androgen deprivation therapy (ADT), a significant positive correlation was found between TTNpsa, nadir PSA (Npsa) duration, and progression-free survival (PFS) ( p < 0.001) and overall survival (OS) ( p < 0.001). There was no correlation between TTNpsa and Npsa duration. TTNpsa and Npsa durations were independently correlated with PFS and OS. In patients with TTNpsa value ≥19 weeks, the median PFS was 126 (95% CI, 68-184) weeks compared with TTNpsa <19-week group in which the median PFS was 44 (95% CI, 26-62) weeks ( p = 0.033). In patients with TTNpsa value ≥19 weeks, the median OS was 242 (95% CI, 169-315) weeks compared with TTNpsa <19-week group in which the OS was 156 (95% CI, 89-223) weeks ( p = 0.018). The median nadir PSA value was 1 ng/mL. The median PFS was significantly longer in the patient group with ≤1 ng/mL (137 weeks, 95% CI, 50-224) compared with the group with >1 ng/mL (41 weeks, 95% CI, 34-48) ( p < 0.001). The median OS was significantly longer in the patient group with nadir PSA ≤1 ng/mL (296 weeks, 95% CI, 220-272) compared to the group with >1 ng/mL (131 weeks, 95% CI, 84-178) ( p = 0.002). In patients with nadir PSA ≤1 ng/mL ( n = 40), there was no relationship between TTNpsa and Npsa duration with both PFS and OS. However, in patients with nadir PSA >1 ng/mL ( n = 40) subgroup, there was a significant positive correlation between TTNpsa and PFS, and OS ( p < 0.001, P = 0.016, respectively). In CN-MPC who received first-line ADT, especially in the group with the nadir PSA value >1 ng/mL, the duration of TTNpsa was positively correlated with PFS and OS.

Risk Factors for Prostate Cancer Resistance to First-Line Androgen Deprivation Therapy (ADT)

Introduction: Androgen deprivation therapy is the mainstay of systemic treatment for metastatic prostate. However, the majority of patients progress to CRPC. The aim of this study is to identify factors that predict castration resistance in men with locally advanced or metastatic prostate cancer treated with first line ADT. Methods: This is a retrospective and analytical study including 46 patients treated for advanced or metastatic prostate cancer with first-line ADT at the Military Hospital Mohammed 5 of Rabat (HMMV) between November 2013 and July 2018 (a period of 5 years). The elements analyzed were sociodemographic, clinical, patient history, biological and radiological data. Results: Predictive factors for castration resistance in our sample are: 1) A high-risk stage according to the LATITUDE criteria. 2) High initial PSA. 3) PSA nadir (PSAn) &gt; 1.17 ng/ml. 4) Elevated PAL at diagnosis &gt; 129 IU/L. 5) Short time to reach PSAn ≤ 9 months. Conclusion: The risk factors predictive of early resistance to first-line hormonal therapy in patients with metastatic prostate cancer in our series were similar to those described in the literature. We advocate early treatment with hormonal chemotherapy in any patient with metastatic prostate cancer who has any of the elements identified in our study.

Radium-223 for patients with metastatic castration-resistant prostate cancer with asymptomatic bone metastases progressing on first-line abiraterone acetate or enzalutamide: A single-arm phase II trial

PurposeThe paper aims to evaluate the efficacy and safety of 223Ra in patients who progressed after first-line androgen deprivation therapy. Patients and methodsEXCAAPE (NCT03002220) was a multicentre, single-arm, open-label, non-controlled phase IIa trial in 52 patients with metastatic castration-resistant prostate cancer and asymptomatic bone metastases who have progressed on abiraterone acetate or enzalutamide, up to six doses of 223Ra (55 kBq/kg of body weight per month). The primary end-point was radiographic progression-free survival (rPFS). Secondary end-points included rPFS based on androgen receptor splice variant 7 (AR-V7) expression in circulating tumour cells (CTCs), overall survival, and safety. ResultsMedian rPFS was 5.5 months (95% CI 5.3–5.5). Median rPFS of patients with AR-V7(−) CTCs was longer than that of patients with AR-V7(+) CTCs (5.5 versus 2.2 months, respectively; P = 0.056). Median overall survival was 14.8 months (95% CI 11.2–not reached) and was significantly greater for AR-V7(−) patients than for AR-V7(+) patients (14.8 months versus 3.5 months, respectively; P < 0.01). 223Ra was well tolerated; anaemia and thrombocytopenia were the most common grade 3/4 adverse events (5.8% and 11.5%, respectively). Conclusions223Ra seems to be a reasonable treatment for patients with metastatic castration-resistant prostate cancer and asymptomatic bone metastases progressing on novel hormonal therapy and had an acceptable safety profile.

Cost-utility analysis of adding abiraterone acetate plus prednisone/prednisolone to long-term hormone therapy in newly diagnosed advanced prostate cancer in England: Lifetime decision model based on STAMPEDE trial data.

Adding abiraterone acetate (AA) plus prednisolone (P) to standard of care (SOC) improves survival in newly diagnosed advanced prostate cancer (PC) patients starting hormone therapy. Our objective was to determine the value for money to the English National Health Service (NHS) of adding AAP to SOC. We used a decision analytic model to evaluate cost-effectiveness of providing AAP in the English NHS. Between 2011-2014, the STAMPEDE trial recruited 1917 men with high-risk localised, locally advanced, recurrent or metastatic PC starting first-line androgen-deprivation therapy (ADT), and they were randomised to receive SOC plus AAP, or SOC alone. Lifetime costs and quality-adjusted life-years (QALYs) were estimated using STAMPEDE trial data supplemented with literature data where necessary, adjusting for baseline patient and disease characteristics. British National Formulary (BNF) prices (£98/day) were applied for AAP. Costs and outcomes were discounted at 3.5%/year. AAP was not cost-effective. The incremental cost-effectiveness ratio (ICER) was £149,748/QALY gained in the non-metastatic (M0) subgroup, with 2.4% probability of being cost-effective at NICE's £30,000/QALY threshold; and the metastatic (M1) subgroup had an ICER of £47,503/QALY gained, with 12.0% probability of being cost-effective. Scenario analysis suggested AAP could be cost-effective in M1 patients if priced below £62/day, or below £28/day in the M0 subgroup. AAP could dominate SOC in the M0 subgroup with price below £11/day. AAP is effective for non-metastatic and metastatic disease but is not cost-effective when using the BNF price. AAP currently only has UK approval for use in a subset of M1 patients. The actual price currently paid by the English NHS for abiraterone acetate is unknown. Broadening AAP's indication and having a daily cost below the thresholds described above is recommended, given AAP improves survival in both subgroups and its cost-saving potential in M0 subgroup.

Multigene Profiling of Circulating Tumor Cells (CTCs) for Prognostic Assessment in Treatment-Naïve Metastatic Hormone-Sensitive Prostate Cancer (mHSPC).

The substantial biological heterogeneity of metastatic prostate cancer has hindered the development of personalized therapeutic approaches. Therefore, it is difficult to predict the course of metastatic hormone-sensitive prostate cancer (mHSPC), with some men remaining on first-line androgen deprivation therapy (ADT) for several years while others progress more rapidly. Improving our ability to risk-stratify patients would allow for the optimization of systemic therapies and support the development of stratified prospective clinical trials focused on patients likely to have the greatest potential benefit. Here, we applied a liquid biopsy approach to identify clinically relevant, blood-based prognostic biomarkers in patients with mHSPC. Gene expression indicating the presence of CTCs was greater in CHAARTED high-volume (HV) patients (52% CTChigh) than in low-volume (LV) patients (23% CTChigh; * p = 0.03). HV disease (p = 0.005, q = 0.033) and CTC presence at baseline prior to treatment initiation (p = 0.008, q = 0.033) were found to be independently associated with the risk of nonresponse at 7 months. The pooled gene expression from CTCs of pre-ADT samples found AR, DSG2, KLK3, MDK, and PCA3 as genes predictive of nonresponse. These observations support the utility of liquid biomarker approaches to identify patients with poor initial response. This approach could facilitate more precise treatment intensification in the highest risk patients.

Differential impact of tumor suppressor gene (TP53, PTEN, RB1) alterations and treatment outcomes in metastatic, hormone-sensitive prostate cancer

BackgroundAltered tumor suppressor genes (TSG-alt) in prostate cancer are associated with worse outcomes. The prognostic value of TSG-alt in metastatic, hormone-sensitive prostate cancer (M1-HSPC) is unknown. We evaluated the effects of TSG-alt on outcomes in M1-HSPC and their prognostic impact by first-line treatment.MethodsWe retrospectively identified patients with M1-HSPC at our institution treated with first-line androgen deprivation therapy plus docetaxel (ADT + D) or abiraterone acetate (ADT + A). TSG-alt was defined as any alteration in one or more TSG. The main outcomes were Kaplan–Meier-estimated progression-free survival (PFS) and overall survival, analyzed with the log-rank test. Clinical characteristics were compared with the χ2 test and Kruskal–Wallis rank sum test. Cox regression was used for univariate and multivariable analyses.ResultsWe identified 97 patients with M1-HSPC: 48 (49%) with ADT + A and 49 (51%) with ADT + D. Of 96 patients with data available, 33 (34%) had 1 TSG-alt, 16 (17%) had 2 TSG-alt, and 2 (2%) had 3 TSG-alt. The most common alterations were in TP53 (36%) and PTEN (31%); 6% had RB1 alterations. Median PFS was 13.1 (95% CI, 10.3–26.0) months for patients with normal TSGs (TSG-normal) vs. 7.8 (95% CI, 5.8–10.5) months for TSG-alt (P = 0.005). Median PFS was lower for patients with TSG-alt vs TSG-normal for those with ADT + A (TSG-alt: 8.0 [95% CI, 5.8–13.8] months vs. TSG-normal: 23.2 [95% CI, 13.1–not estimated] months), but not with ADT + D (TSG-alt: 7.8 [95% CI, 5.7–12.9] months vs. TSG-normal: 9.5 [95% CI, 4.8–24.7] months). On multivariable analysis, only TSG-alt predicted worse PFS (hazard ratio, 2.37; 95% CI, 1.42–3.96; P < 0.001).ConclusionsThe presence of TSG-alt outperforms clinical criteria for predicting early progression during first-line treatment of M1-HSPC. ADT + A was less effective in patients with than without TSG-alt. Confirmation of these findings may establish the need for inclusion of molecular stratification in treatment algorithms.

High Serum Alkaline Phosphatase Flare after First-Line Androgen Deprivation Therapy Predicts Poor Prognosis in Metastatic Prostate Cancer Patients Treated with Second-Generation Androgen Receptor Targeted Therapy.

Objectives To determine whether an alkaline phosphatase (ALP) flare after androgen deprivation therapy (ADT) is associated with the treatment response in castration-resistant prostate cancer (CRPC) and predicts the prognosis of metastatic prostate cancer (PCa) patients. Methods One hundred and nineteen patients diagnosed with metastatic PCa between 2008 and 2017 were retrospectively studied. The ALP flare ratio was calculated as the ratio of ALP levels 1 month after beginning ADT to ALP levels at diagnosis. The association of the ALP flare ratio with the prostate-specific antigen (PSA) response to CRPC treatment (second-generation androgen receptor targeted therapy (ART) or docetaxel), time to CRPC, and overall survival (OS) were investigated. Results The time to CRPC and OS was significantly longer in patients with an ALP flare ratio less than 1.33 compared to a ratio more than 1.33. No difference in PSA response was seen regarding the ALP flare ratio in both ART and docetaxel treatment. Second-generation ART-treated patients with a low ALP flare ratio showed longer OS than those with a higher ALP flare ratio (p=0.0367). However, no difference was seen between a high and low ALP flare ratio (p=0.8054) in docetaxel-treated patients. The ALP flare ratio was the most significant prognostic factor for OS (p < 0.0001). Conclusions A higher ALP flare ratio after first-line ADT was a significant prognostic factor in metastatic PCa, especially in patients treated with second-generation ART for CRPC. Chemotherapy for patients with a higher ALP flare ratio 1 month after induction of ADT may be a clinically relevant decision.

Role of the runt-related transcription factor (RUNX) family in prostate cancer.

Prostate cancer (PCa) is a very complex disease that is a major cause of death in men worldwide. Currently, PCa dependence on the androgen receptor (AR) has resulted in use of AR antagonists and antiandrogen therapies that reduce endogenous steroid hormone production. However, within two to three years of receiving first-line androgen deprivation therapy, the majority of patients diagnosed with PCa progress to castration-resistant prostate cancer (CRPC). There is an urgent need for therapies that are more durable than antagonism of the AR axis. Studies of runt-related transcription factors (RUNX) and their heterodimerization partner, core-binding factor subunit b (CBFβ), are revealing that the RUNX family are drivers of CRPC. In this review, we describe what is presently understood about RUNX members in PCa, including what regulates and is regulated by RUNX proteins, and the role of RUNX proteins in the tumor microenvironment and AR signaling. We discuss the implications for therapeutically targeting RUNX, the potential for RUNX as PCa biomarkers, and the current pressing questions in the field.

SPOP mutations in prostate cancer: Clinical and genomic features.

151 Background: Point mutations in the gene encoding speckle-type pox virus and zinc finger protein (SPOP) are the most frequently identified mutations in prostate cancer, occurring at a frequency of 6-15% across localized and disseminated cancers. Recently, SPOP gene alterations have gained attention as they appear to define a novel subclass of prostate cancers. Previous studies show that patients with mutant SPOP (mtSPOP) had superior responses to androgen deprivation therapy (ADT) and exhibit more favorable responses to abiraterone compared to wild type SPOP (wtSPOP). Methods: We retrospectively identified 59 prostate cancer patients at a single institution (Johns Hopkins) with somatic SPOP mutations from genomic testing of primary tumors (n=45), metastatic lesions (n=12), or liquid biopsies (n=2). Patient records were reviewed to determine baseline characteristics, therapies received, and clinical outcomes. The primary outcomes included best PSA response and progression-free survival (PFS) on ADT in the hormone sensitive prostate cancer (HSPC) setting and on abiraterone and/or enzalutamide in the first-line castration resistant prostate cancer (CRPC) setting. PFS was defined as either PSA, radiographic, or clinical progression. Results: The median age at diagnosis was 64 years (range 46 to 85). 17/59 (28.8%) were Black. F133 was the most frequently mutated residue, occurring in 33 (55.9%) instances (Table). There were two patients who harbored two mutations in the SPOP gene. The most frequently co-occurring mutation was in APC (15/59 [25.4%] patients), resulting in Wnt pathway activation. Concurrent ERG fusions were not observed with this cohort (0/59 [0%] patients). 41/59 (69.4%) were diagnosed with Gleason 8-10 disease. 21/59 (35.5%) were diagnosed with de novo metastatic disease. 50/59 (84.7%) patients received ADT for recurrent or metastatic disease. Median PFS on ADT was 40.7 (95% CI 23.4-71.9) months. Of the 27/59 (45.8%) patients who progressed to CRPC, 20/59 (33.9%) patients received abiraterone and 13/59 (22.0%) received enzalutamide; 9/59 (15.3%) patients received both agents. Median PFS was 7.8 (95% CI 6.7-NR) months on abiraterone and 7.3 (95% CI 3.2-NR) months on enzalutamide. Other notable therapies received in the CRPC setting include docetaxel (5/59 [8.5%] patients), cabazitaxel (5/59 [8.5%] patients), and PARP inhibitor olaparib or rucaparib (4/59 [6.8%] patients). Conclusions: SPOP mutations define a unique subset of prostate cancers enriched for black patients, high Gleason scores, absence of ERG fusions, and Wnt pathway activation. Clinical outcomes to first-line ADT appear longer than expected for genomically-unselected patients. [Table: see text]

Risk of major adverse cardiovascular events among second-line hormonal therapy for metastatic castration-resistant prostate cancer: A real-world evidence study.

To evaluate the possible major adverse cardiovascular events (MACE) associated with second-line hormonal therapy in patients with metastatic castration-resistant prostate cancer (mCRPC). We performed a population-based real-world cohort study of 4962 prostate cancer patients between 2014 and 2017 utilizing the Chang Gung Research Database of Taiwan. The second-line hormonal therapies included enzalutamide and abiraterone acetate. The outcomes of interest were MACE, including acute coronary syndrome (ACS), ischemic stroke (IS), and heart failure (HF) events that resulted in hospitalization. Cox proportional-hazards models with inverse probability of treatment weighting (IPTW) with propensity scores were used. After IPTW, 288 patients were prescribed second-line hormonal therapy and 1575 received first-line androgen-deprivation therapy (ADT). Of all patients diagnosed with MACE, the event rates were 2.92% in the second-line hormonal group and 2.22% in the first-line ADT group. The mean follow-up period was 9.52 months for the second-line hormonal group. Patients who received second-line hormonal therapy exhibited a significantly increased risk for MACE (hazard ratio [HR]: 3.15; 95% confidence interval [CI]: 2.03-4.89), ACS (HR: 4.94; 95% CI: 2.36-10.33), and HF (HR: 2.83; 95% CI: 1.53-5.25), compared with the first-line ADT group, but a similar risk for IS was observed in both groups (HR: 1.70; 95% CI: 0.95-3.04). The real-world evidence study revealed increased risks for MACE in mCRPC patients receiving second-line hormonal therapy.

Prostate Cancer Central Nervous System Metastasis in a Contemporary Cohort.

Central nervous system (CNS) metastasis from prostate cancer (PCA) is a rare event, but one with significant prognostic impact for those affected. There are limited data on its impact in contemporary cohorts treated with modern agents. A retrospective institutional review was performed to characterize the occurrence/outcome of PCA CNS metastasis on all cases of PCA from 2011 to 2017. A manual chart review was performed to confirm PCA CNS metastases in all cases identified through a diagnostic code screening of the health data. A total of 6596 cases of PCA were identified, with 29 (20 dural and 9 intraparenchymal) confirmed cases of CNS metastases from PCA. The median survival from the time of diagnosis of CNS metastasis was 2.6 months (95% confidence interval, 2.04-10.78 months) and 5.41 months (95% confidence interval, 3.03 months to not reached) for dural and parenchymal metastases, respectively. Among those who developed CNS metastases, approximately 79% of patients had prior exposure to abiraterone and/or enzalutamide, of whom 50% had≥ 6 months of exposure. Four (0.07%) of the 5841 patients developed CNS metastases prior to the initiation of therapy or on androgen deprivation therapy alone. In contrast, 24 (8.6%) of the 279 patients with 2 or more lines of medical therapy developed CNS metastases. Our analysis highlights the continued poor prognosis of parenchymal and dural CNS metastases from PCA. CNS metastases in PCA remain a rare event with a 0.4% incidence in this series, but this incidence is considerably increased in patients who receive medical therapy beyond first-line androgen deprivation therapy.

Interleukin-10 Induces Expression of Neuroendocrine Markers and PDL1 in Prostate Cancer Cells.

Interleukin-10 (IL10) is best studied for its inhibitory action on immune cells and ability to suppress an antitumour immune response. But IL10 also exerts direct effects on nonimmune cells such as prostate cancer epithelial cells. Elevated serum levels of IL10 observed in prostate and other cancer patients are associated with poor prognosis. After first-line androgen-deprivation therapy, prostate cancer patients are treated with androgen receptor antagonists such as enzalutamide to inhibit androgen-dependent prostate cancer cell growth. However, development of resistance inevitably occurs and this is associated with tumour differentiation to more aggressive forms such as a neuroendocrine phenotype characterized by expression of neuron specific enolase and synaptophysin. We found that treatment of prostate cancer cell lines in vitro with IL10 or enzalutamide induced markers of neuroendocrine differentiation and inhibited androgen receptor reporter activity. Both also upregulated the levels of PDL1, which could promote tumour survival in vivo through its interaction with the immune cell inhibitory receptor PD1 to suppress antitumour immunity. These findings suggest that IL10's direct action on prostate cancer cells could contribute to prostate cancer progression independent of IL10's suppression of host immune cells.

AZGP1 Protein Expression in Hormone-Naïve Advanced Prostate Cancer Treated with Primary Androgen Deprivation Therapy.

Biomarkers for predicting the risk of castration-resistant prostate cancer (CRPC) in men treated with primary androgen deprivation therapy (ADT) are lacking. We investigated whether Zinc-alpha 2 glycoprotein (AZGP1) expression in the diagnostic biopsies of men with hormone-naïve prostate cancer (PCa) undergoing primary ADT was predictive of the development of CRPC and PCa-specific mortality. The study included 191 patients who commenced ADT from 2000 to 2011. The AZGP1 expression was evaluated using immunohistochemistry and scored as high or low expression. The risks of CRPC and PCa-specific mortality were analyzed using stratified cumulative incidences and a cause-specific COX regression analysis for competing risk assessment. The median follow-up time was 9.8 (IQR: 6.1–12.7) years. In total, 94 and 97 patients presented with low and high AZGP1 expression, respectively. A low AZGP1 expression was found to be associated with a shorter time to CRPC when compared to patients with a high AZGP1 expression (HR: 1.5; 95% CI: 1.0–2.1; p = 0.03). However, the multivariable analysis demonstrated no added benefit by adding the AZGP1 expression to prediction models for CRPC. No differences for PCa-specific mortality between the AZGP1 groups were observed. In conclusion, a low AZGP1 expression was associated with a shorter time to CRPC for PCa patients treated with first-line ADT but did not add any predictive information besides well-established clinicopathological variables.

Treatment with abiraterone and enzalutamide does not overcome poor outcome from metastatic castration-resistant prostate cancer in men with the germline homozygous HSD3B1 c.1245C genotype

In men with castration-sensitive prostate cancer (CSPC), the HSD3B1 c.1245A>C variant has been reported to be associated with shorter responses to first-line androgen-deprivation therapy (ADT). Here, we evaluated the association between the inherited HSD3B1 c.1245A>C variant and outcomes from metastatic castration-resistant prostate cancer (mCRPC) after first-line treatment with abiraterone (Abi) or enzalutamide (Enza). Patients with mCRPC (n= 266) were enrolled from two centers at the time of starting first-line Abi/Enza. Outcomes after Abi/Enza included best prostate-specific antigen (PSA) response, treatment duration, and overall survival (OS). Outcomes after first-line ADT were determined retrospectively, and included treatment duration and OS. As was prespecified, we compared patients with the homozygous variant HSD3B1 genotype (CCgenotype) versus the combined group with the heterozygous (AC) and homozygous wild-type (AA) genotypes. Among the 266 patients, 22 (8.3%) were homozygous for the HSD3B1 variant (CC). The CC genotype had no association with PSA response rate; the median Abi/Enza treatment duration was 7.1 months for the CC group and 10.3 months for the AA/AC group (log rank P= 0.34). Patients with the CC genotype had significantly worse OS, with median survival at 23.6 months for the CC group and 30.7 months for the AA/AC group (log rank P= 0.02). In multivariable analysis adjusting for age, Gleason score, PSA, prior chemotherapy, and M1 disease, the association between the CC genotype and OS remained significant (hazard ratio 1.78, 95% confidence interval 1.03-3.07, P= 0.04). Poor outcome after first-line ADT in the CC group was also observed when evaluating retrospective ADT duration data for the same combined cohort. In this large two-center study evaluating the HSD3B1 c.1245 genotype and outcomes after first-line Abi/Enza, homozygous variant (CC) HSD3B1 genotype was associated with worse outcomes. Novel therapeutic strategies are needed to enable treatment selection based on this genetic marker.

Genomic and clinical characterization of pulmonary-only metastatic prostate cancer: A unique molecular subtype.

Isolated pulmonary involvement is uncommon in metastatic hormone-sensitive prostate cancer (mHSPC). To characterize outcomes and molecular alterations of this unique patient subset, we conducted a retrospective review of patients with hormone-naïve prostate cancer presenting with lung-only metastases. This was a retrospective single-institution study. Medical records of 25 patients presenting with pulmonary-only metastases before receiving androgen deprivation therapy (ADT) were analyzed. Germline and/or somatic genomic results, where available (n = 16), were documented. Tumor tissue was analyzed using clinical-grade next-generation DNA sequencing assays. Clinical endpoints included complete prostate-specific antigen (PSA) response to ADT (<0.1 ng/mL), median overall survival (OS) from time of ADT initiation, median PSA progression-free survival (PSA-PFS), and failure-free survival (FFS) at 4 years. Baseline characteristics were notable for 48% of men (12 of 25) having first or second-degree relatives with prostate cancer, compared with 20% expected. Complete PSA responses to ADT were noted in 52% of men, with a median PSA-PFS of 66 months, a 4-year FFS rate of 72%, and a median OS that was not reached after 190 months. In evaluable patients, molecular drivers were enriched for mismatch repair mutations (4 of 16, 25%) and homologous-recombination deficiency mutations (4 of 16, 25%). These results are limited by the small sample size and retrospective nature of this analysis. This exploratory study represents one of the largest cohorts of lung-only mHSPC patients to-date. The prevalence of actionable DNA-repair gene alterations was higher than anticipated (any DNA-repair mutation: 8 of 16, 50%). Compared to historical data, these patients appear to have exceptional and durable responses to first-line ADT. This study suggests that pulmonary-tropic mHSPC biology may be fundamentally different from nonpulmonary mHSPC.

First Line Androgen Deprivation Therapy vs. Chemotherapy for Patients With Androgen Receptor Positive Recurrent or Metastatic Salivary Gland Carcinoma-A Retrospective Study.

Objectives: There is a lack of effective therapy for recurrent or metastatic salivary gland carcinoma. Androgen deprivation therapy has demonstrated efficacy in cases of salivary duct carcinoma (SDC) and high-grade adenocarcinoma not otherwise specified (NOS) that express androgen receptor.Materials and Methods: We conducted a single institution retrospective cohort study examining patients treated for recurrent/metastatic SDC or high-grade adenocarcinoma NOS of the salivary gland. Survival analyses were performed to assess for efficacy of first-line androgen deprivation therapy (ADT) vs. first-line conventional cytotoxic chemotherapy. Efficacy of salvage ADT was also assessed.Results: Fifty-eight patients were reviewed. Thirty-five patients had recurrent/metastatic disease of which 28 had SDC (80%) and 7 had high-grade adenocarcinoma NOS (20%). Median overall survival for first-line ADT was 25 months compared to 25 months for first-line chemotherapy [RR 0.54 (0.23–1.28, p = 0.16)]. Patients treated with first-line ADT had a response rate of 45% (9/20) and patients treated with first-line chemotherapy had a response rate of 14% (2/14). Six patients received salvage ADT with 1 patient demonstrating complete response and 3 with stable disease as best response (clinical benefit rate 67%).Conclusion: Overall survival for first line ADT and first line cytotoxic chemotherapy was comparable but response rates to first-line ADT were higher than those with first-line chemotherapy. Salvage ADT is active in recurrent/metastatic salivary gland carcinoma.

Abstract 436: Prediction of aggressive disease in metastatic castration-resistant prostate cancer: The role of very small nuclear circulating tumor cells

Abstract Background: Circulating tumor cells (CTCs) have arisen as a contemporary noninvasive prognostic biomarker for prostate cancer (PC). Previously, a subgroup of PC CTCs, with particularly small nuclei (&amp;lt;8.54 μm), were found to be correlated with poor prognosis and the emergence of visceral metastases (VM). This subgroup was named very-small nuclear CTCs (vsnCTCs). We proposed vsnCTCs as a biomarker of aggressive disease in metastatic castration-resistant PC (mCRPC). Previous Studies also showed that the disruption of emerin, a linker of nucleoskeleton and cytoskeleton complex proteins, increases the cancer cells' capacity of migration and invasion. We hypothesize that emerin mislocalization is potentially associated with vsnCTC formation and may be a critical step for metastasis. Methods: 35 blood samples were obtained from PC patients who failed first-line androgen deprivation therapy (ADT) and starting 2nd line treatment with abiraterone, enzalutamide, or taxane-based chemotherapy. Using our NanoVelcro CTC assay, we captured, subclassified, and enumerated the CTCs from patient samples with high-resolution imaging. Survival analyses were performed to exam the correlation between vsnCTC presence and patients’ prognosis. Concurrently, emerin staining was performed and the distribution and expression levels of emerin were analyzed in selected vsnCTC samples. Results: The presence of one or more vsnCTCs strongly correlated with inferior overall survival (OS), progression free survival (PFS), and time to VM (TTVM). We also observed lower emerin content in vsnCTCs compared to WBC, and more prominent emerin mislocalization in vsnCTCs compared to CTCs with larger nuclei. Conclusion: Our study strongly demonstrated the importance of morphologic characterization of CTCs and suggested that vsnCTC is a blood-borne biomarker for prediction of aggressive disease. Additionally, emerin mislocalization in vsnCTCs could be a potential biological pathway behind this morphologic phenomenon. Citation Format: Pin-Jung Chen, Yu Jen Jan, Pai-Chi Teng, Jie-Fu Chen, Shirley Cheng, Nu Yao, Mariana Reis-Sobreiro, Amber Lozano, Amy Gomez, Hsian-Rong Tseng, Michael Freeman, Edwin Posadas. Prediction of aggressive disease in metastatic castration-resistant prostate cancer: The role of very small nuclear circulating tumor cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 436.

Inhibition of EGFR signaling with Spautin-1 represents a novel therapeutics for prostate cancer

BackgroundProstate cancer (PCa) remains a challenge worldwide. Due to the development of castration-resistance, traditional first-line androgen deprivation therapy (ADT) became powerlessness. Epidermal growth factor receptor (EGFR) is a well characterized therapeutic target to treat colorectal carcinoma and non-small cell lung cancer. Increasing studies have unraveled the significance of EGFR and its downstream signaling in the progression of castration-resistant PCa.MethodMTS, colony formation and Edu staining assays were used to analyze the cell proliferation of PCa cells. Flow cytometry was used to analyze PCa cell cycle distribution and cell apoptosis. Western blot was used to measure the expression of key proteins associated with cell cycle progression, apoptosis and EGFR signaling pathways. Transfection of exogenous small interfering RNA (siRNA) or plasmid was used to intervene specific gene expression. Nude mouse model was employed to test the in vivo effect of Spautin-1.ResultsThe current study reveals that Spautin-1, a known inhibitor of ubiquitin-specific peptidase 10 (USP10) and USP13, inhibits EGFR phosphorylation and the activation of its downstream signaling. Inhibition of EGFR signaling induced by Spautin-1 leads to cell cycle arrest and apoptosis of PCa in a USP10/USP13 independent manner. The application of Spautin-1 reduces the expression of glucose transporter 1 (Glut1) and dramatically induces cell death under glucose deprivation condition. In vivo experiments show a potent anti-tumor effect of Spautin-1 alone and in combination with Enzalutamide.ConclusionThis study demonstrates the therapeutic potential of EGFR signaling inhibition by the use of Spautin-1 for PCa treatment.