Radioiodine therapy for castration-resistant prostate cancer following prostate-specific membrane antigen promoter-mediated transfer of the human sodium iodide symporter

Radioiodine therapy, the most effective form of systemic radiotherapy available, is currently useful only for thyroid cancer because of the thyroid-specific expression of the human sodium iodide symporter （hNIS）. Here, we explore the efficacy of a novel form of gene therapy using prostate-specific membrane antigen （PSMA） promoter-mediated hNIS gene transfer followed by radioiodine administration for the treatment of castration-resistant prostate cancer （CRPC）. The androgen-dependent C33 LNCaP cell line and the androgen-independent C81 LNCaP cell line were transfected by adenovirus. PSMA promoter-hNIS （Ad.PSMApro-hNIS） or adenovirus.cytomegalovirus-hNIS containing the cytomegalovirus promoter （Ad.CMM-hNIS） or a control virus. The iodide uptake was measured in vitro. The in vivo iodide uptake by C81 cell xenografts in nude mice injected with an adenovirus carrying the hNIS gene linked to PSMA and the corresponding tumor volume fluctuation were assessed. Iodide accumulation was shown in different LNCaP cell lines after Ad.PSMApro-hNIS and Ad.CMV-hNIS infection, but not in different LNCaP cell lines after adenovirus.cytomegalovirus （Ad.CMV） infection. At each time point, higher iodide uptake was shown in the C81 cells infected with Ad.PSMApro-hNIS than in the C33 cells （P 〈 0.05）. An in vivo animal model showed a significant difference in 1311 radioiodine uptake in the tumors infected with Ad.PSMApro-hNIS, Ad.CMV-hNIS and control virus （P 〈 0.05） and a maximum reduction of tumor volume in mice infected with Ad.PSMApro-hNIS. These results show prostate-specific expression of the hNIS gene delivered by the PSMA promoter and effective radioiodine therapy of CRPC by the PSMA promoter-driven hNIS transfection.

Prognostic factors in Chinese patients with metastatic castration-resistant prostate cancer treated with docetaxel-based chemotherapy

This study aims to evaluate the potential value of patient characteristics in predicting overall survival （OS） in patients with metastatic castration-resistant prostate cancer （mCRPC） treated with docetaxel-based thermotherapy. A total of 115 patients with mCRPC undergoing a docetaxel q3w regimen were enrolled in this study. A survival analysis was performed using the Kaplan-Meier method. Cox proportional hazards models were used to evaluate the prognostic value of all covariates for OS. OS was also analysed after stratifying patients according to the results of multivariate analysis. The median OS for the entire cohort was 17.0 months. The multivariate analysis showed that the prostate-specific antigen doubling time （PSADT）, baseline haemoglobin （Hb） concentration, alkaline phosphatase （ALP） concentration, cycles of chemotherapy and time to castration resistance were independent prognostic factors of OS. According to the presence of PSADT 〈46.3 days and baseline ALP/〉 110 IU 1-1, all patients were divided into three risk groups： low-risk group （no risk factors）, intermediate-risk group （one risk factor） and high-risk group （two risk factors）. Median OSs for patients in low-, intermediate- and high-risk groups were 28.0 months （95% Ch 23.8-32.2）, 21.0 months （95% Ch 18.9-23.1） and 11.0 months （95% Ch 7.6-14.4）, respectively （P〈O.O01）. In conclusion, PSADT, baseline Hb concentration, ALP concentration, cycles of chemotherapy and time to castration resistance were independent prognostic factors of OS in Chinese patients with mCRPC treated with docetaxel. PSADT combined with the baseline ALP concentration could be a useful risk stratification parameter for evaluating survival outcomes.

Androgen synthesis inhibitors in the treatment of castration-resistant prostate cancer

Suppression of gonadal testosterone synthesis represents the standard first line therapy for treatment of metastatic prostate cancer. However, in the majority of patients who develop castration-resistant prostate cancer （CRPC）, it is possible to detect persistent activation of the androgen receptor （AR） through androgens produced in the adrenal gland or within the tumor itself. Abiraterone acetate was developed as an irreversible inhibitor of the dual functional cytochrome P450 enzyme CYP17 with activity as a 17（^-hydroxylase and 17,20-1yase. CYP17 is necessary for production of nongonadal androgens from cholesterol. Regulatory approval of abiraterone in 2011, based on a phase III trial showing a significant improvement in overall survival （OS） with abiraterone and prednisone versus prednisone, represented proof of principle that targeting AR is essential for improving outcomes in men with CRPC. Inhibition of 17α-hydroxylase by abiraterone results in accumulation of upstream mineralocorticoids due to loss of cortisol-mediated suppression of pituitary adrenocorticotropic hormone （ACTH）, providing a rationale for development of CYP17 inhibitors with increased specificity for 17,20-1yase （orteronel, galeterone and VT-464） that can potentially be administered without exogenous corticosteroids. In this article, we review the development of abiraterone and other CYP17 inhibitors; recent studies with abiraterone that inform our understanding of clinical parameters such as drug effects on quality-of-life, potential early predictors of response, and optimal sequencing of abiraterone with respect to other agents; and results of translational studies providing insights into resistance mechanisms to CYP17 inhibitors leading to clinical trials with drug combinations designed to prolong abiraterone benefit or restore abiraterone activity.

Surface-enhanced Raman spectroscopy of serum predicts sensitivity to docetaxel-based chemotherapy in patients with metastatic castration-resistant prostate cancer

Docetaxel-based chemotherapy,as the first-line treatment for metastatic castration-resistant prostate cancer(mCRPC),has succeeded in helping quite a number of patients to improve quality of life and prolong survival time.However,almost half of mCRPC patients are not sensitive to docetaxel chemotherapy initially.This study aimed to establish models to predict sensitivity to docetaxel chemotherapy in patients with mCRPC by using serum surface-enhanced Raman spectroscopy(SERS).A total of 32 mCPRC patients who underwent docetaxel chemo-therapy at our center from July 2016 to March 2018 were included in this study.Patients were dichotomized in prostate-specific antigen(PSA)response group(n=17)versus PSA failure group(n=15)according to the response to docetaxel.In total 64 matched spectra from 32 mCRPC patients were obtained by using SERS of serum at baseline(q0)and after 1 cycle of docetaxel chemotherapy(ql).Comparing Raman peaks of serum samples at baseline(q0)be-tween two groups,significant differences revealed at the peaks of 638,810,890(p<0.05)and 1136cm^(-1)(p<0.01).The prediction models of peak 1363 cm^(-1)and principal component anal-ysis and linear discriminant analysis(PCA-LDA)based on Raman data were established,re-spectively.The sensitivity and specificity of the prediction models were 71%,80%and 69%,78%through the way of leave-one-out cross-validation.According to the results of five-cross-valida-tion,the PCA-LDA model revealed an accuracy of 0.73 and AUC of 0.83.

Comparative analysis of the effectiveness of abiraterone before and after docetaxel in patients with metastatic castration-resistant prostate cancer

AIM: To study the efficacy and safety of abiraterone in patients with and without prior chemotherapy.METHODS: The databases including Pub Med and abstracts presented at the American Society of Clinical Oncology meetings up to April 2014 were systematically searched. Eligible studies included randomized controlled trials(RCTs) in which abiraterone plus prednisone was compared to placebo plus prednisone in metastatic castration-resistant prostate cancer(CRPC) patients. The summary incidence, relative risk, hazard ratio and 95%CI were calculated using random or fixed-effects models. Heterogeneity test was performed to test between-study differences in efficacy and toxicity.RESULTS: A total of two phase III RCTs were included in our analysis, with metastatic CPRC patients before(n = 1088) and after chemotherapy(n = 1195). Prior chemotherapy did not significantly alter the effect of abiraterone on overall survival(P = 0.92) and prostatespecific antigen(PSA) progression-free survival(P = 0.13), but reduced its effect on radiographic-prog-ression-free survival(P = 0.04), objective response rate(P < 0.001), and PSA response rate(P < 0.001). Prior chemotherapy significantly increased the specific risk of fluid retention and edema(P < 0.001) and hypokalemia(P < 0.001), but decreased the risk of all-grade hypertension(P < 0.001) attributable to abiraterone. There was no significant difference of cardiac disorders associated with abiraterone between the two settings(P = 0.58). CONCLUSION: Prior chemotherapy may reduce the effectiveness of abiraterone in patients with metastatic CRPC.

The effectiveness of the TAX 327 nomogram in predicting overall survival in Chinese patients with metastatic castration-resistant prostate cancer

Based on the results of TAX 327, a nomogram was developed to predict the overall survival of metastatic castration-resistant prostate cancer （mCRPC） after first-line chemotherapy. The nomogram, however, has not been validated in an independent dataset, especially in a series out of clinical trials. Thus, the objective of the current study was to validate the TAX 327 nomogram in a community setting in China. A total of 146 patients with mCRPC who received first-line chemotherapy （docetaxel or mitoxantrone） were identified. Because clinical trials are limited in China's Mainland, those patients did not receive investigational treatment after the failure of first-line chemotherapy. The predicted overall survival rate was calculated from the TAX 327 nomogram. The validity of the model was assessed with discrimination, calibration and decision curve analysis. The median survival of the cohort was 21 months （docetaxel） and 19 months （mitoxantrone） at last follow-up. The predictive c-index of the TAX 327 nomogram was 0.66 （95% CI： 0.54-0.70）. The calibration plot demonstrated that the 2-year survival rate was underestimated by the nomogram. Decision curve analysis showed a net benefit of the nomogram at a threshold probability greater than 30%. In conclusion, the present validation study did not confirm the predictive value of the TAX 327 nomogram in a contemporary community series of men in China, and further studies with a large sample size to develop or validate nomograms for predicting survival and selecting therapies in advanced prostate cancer are necessary.

Practice patterns and outcomes of equivocal bone scans for patients with castration-resistant prostate cancer: Results from SEARCH

Objective:To review follow-up imaging after equivocal bone scans in men with castration resistant prostate cancer(CRPC)and examine the characteristics of equivocal bone scans that are associated with positive follow-up imaging.Methods:We identified 639 men from five Veterans Affairs Hospitals with a technetium-99m bone scan after CRPC diagnosis,of whom 99(15%)had equivocal scans.Men with equivocal scans were segregated into“high-risk”and“low-risk”subcategories based upon wording in the bone scan report.All follow-up imaging(bone scans,computed tomography[CT],magnetic resonance imaging[MRI],and X-rays)in the 3 months after the equivocal scan were reviewed.Variables were compared between patients with a positive vs.negative follow-up imaging after an equivocal bone scan.Results:Of 99 men with an equivocal bone scan,43(43%)received at least one follow-up imaging test,including 32/82(39%)with low-risk scans and 11/17(65%)with high-risk scans(p=0.052).Of follow-up tests,67%were negative,14%were equivocal,and 19%were positive.Among those who underwent follow-up imaging,3/32(9%)low-risk men had metastases vs.5/11(45%)high-risk men(p=0.015).Conclusion:While 19%of all men who received follow-up imaging had positive follow-up imaging,only 9%of those with a low-risk equivocal bone scan had metastases versus 45%of those with high-risk.These preliminary findings,if confirmed in larger studies,suggest follow-up imaging tests for low-risk equivocal scans can be delayed while high-risk equivocal scans should receive follow-up imaging.

The prognostic factors of effective ketoconazole treatment for metastatic castration-resistant prostate cancer： who can benefit from ketoconazole therapy？

We investigated the prognostic value of some variables of effective ketoconazole treatment for metastatic castration-resistant prostate cancer （mCRPC）. In total, 163 patients with mCRPC were eligible, receiving ketoconazole 200-400 mg three times daily with replacement doses of prednisone. Progression-free survival （PFS） was calculated from the beginning of the ketoconazole therapy to the onset of disease progression. The prognostic value of different variables for PFS was assessed by Cox regression analysis. The median PFS was 2.6 months （0.5-8.6 months） for these patients. The serum testosterone level changed during therapy, which decreased when the prostate-specific antigen （PSA） declined; the serum testosterone level increased as the levels of PSA relapsed. The median PFS values for patients associated with different factors were the following： 1.4 and 3.5 months for a nadir PSA of ≥ 0.2 and 〈0.2 ng ml- 1, respectively （hazard rate （HR）=4.767, P〈0.001）; 3.1 and 1.6 months for a baseline testosterone of ≥0.1 and 〈0.1 ng m1-1, respectively （HR=2.865, P=0.012）; 2.8 and 1.9 months for a baseline haemoglobin of ≥ 120 and 〈120 g 1-1, respectively （HR= 1.605, P〈0.001）; and 3.0 and 1.9 months for a PSA doubling time （PSADT） of ≥ 2.0 and 〈2.0 months, respectively （HR= 1.454, P=-0.017）. A risk model was constructed according to the four factors that divided patients into three subgroups of low risk （0-1 factors）, moderate risk （2 factors） and high risk （3-4 factors） with PFS values of 3.6, 3.0 and 1.4 months, respectively （HR=1.619, P〈0.001）. A nadir PSA of ≥0.2 ng m1-1, a baseline testosterone of 〈0.1 ng m1-1, a baseline haemoglobin of 〈 120 g I- 1 and a PSADT of 〈2 months were associated with a poor PFS. This risk model could provide evidence to predict the survival benefit of ketoconazole therapy.

Nonmetastatic castration-resistant prostate cancer: Novel agents to treat a lethal disease

Nonmetastatic castration-resistant prostate cancer(nmCRPC)-defined as prostate-specific antigen(PSA)>2 ng/mL,testosterone castration levels<1.7 nm/L,and the absence of metastatic lesions on conventional imaging(computed tomography or bone scan)-has been defined as a lethal disease by the Prostate Cancer Work Group.One-third of patients with prostate cancer who receive androgen deprivation therapy for biochemical recurrence after local treatment will develop CRPC,with death occurring an average of 2.5 years after diagnosis of castration resistance.Most patients diagnosed with nmCRPC are asymptomatic or minimally symptomatic at diagnosis due to local treatment.In patients with short PSA doubling times(<10 mo)and high baseline PSA levels,there is a high risk of bone metastases followed by prostate cancer-related mortality.These patients also present significant morbidity that negatively impacts quality of life(QoL).Recently,the results of three randomized trials(PROSPER,SPARTAN,and ARAMIS)were published.Those trials evaluated the efficacy of three different androgen receptor inhibitors-enzalutamide,apalutamide,and darolutamide-in patients with nmCRPC.In all three trials,the study drugs improved both metastasis-free survival and overall survival compared to placebo,plus on-going androgen deprivation therapy without a negative impact on QoL.In patients with nmCRPC,the most important clinical objective is early detection and treatment to maintain a low tumor burden and to prolong the symptom-free interval.For patients with nmCRPC,these novel drugs offer new hope for better QoL and survival outcomes.

Androgen receptor mediated resistance in the progression of castration-resistant prostate cancer

The incidence of prostate cancer has increased year by year in the world.Despite improvements in diagnosis,surgical techniques,and drugs,survival rates of prostate cancer have improved little,and most prostate cancer-related deaths are as a result of castration resistant prostate cancer(CRPC),which progresses and metastasizes after surgical or medical castration.The pathogenesis of CRPC is still unclear.It has been found that the majority of CRPC patients have overexpression of androgen receptors(ARs),and there are many forms of changes in the signaling pathways that intersect with them during he process to CRPC.Micro ribonucleic acid(miRNA)plays an important role in regulating the expression and translation of prostate cancer target genes,and in the life cycle of cell cycle distribution and apoptosis.Relatedly,active changes in miRNA expression are also closely related to androgen.Therefore,the study of AR-related signaling pathways and AR and miRNA-related signaling pathways is of great significance in the treatment of CRPC.

Radiotherapy of Oligoprogressive Lesions in Castration-Resistant Prostate Cancer: Impact on Second-Generation Hormone Therapy

Background: The therapeutic standard for oligoprogressive prostate cancer resistant to castration is second-generation hormone therapy. This systemic treatment is expensive. There are oligoprogressive lesions accessible to radiotherapy. Objectives: To study the impact of radiotherapy of oligoprogressive lesions on the implementation of second generation hormone therapy. Patients and Methods: A retrospective study from 2012 to 2020 was carried out. All patients with oligoprogressive prostate cancer who had received radiotherapy on one or more lesions in progression were collated. Survival was calculated using the Kaplan-Meier method. Results: 8 patients were treated with stereotactic and conformational radiotherapy between August 2012 and August 2020 in the context of oligoprogressive prostate cancer resistant to castration. The median age at diagnosis of oligoprogression was 73 years with a median PSA level of 3.11 ng/ml. Nine lesions were diagnosed with PET scan PSMA. All the lesions were treated by radiotherapy with different regimens. After a median follow-up of 12.5 months, 7 patients showed a biochemical response to treatment with a median decrease in PSA of 67%. The median survival without clinical or biochemical progression was 7 months. The median survival without the need for further systemic treatment was 9 months. During the follow-up period, six patients received second-generation hormone therapy to treat their relapse, and the other two showed no clinical or biochemical relapse. Conclusion: Radiotherapy may be an alternative to delay the introduction of difficult-to-access second-generation hormone therapy in developing countries. A prospective study could validate this therapeutic approach.

End points of clinical trials in metastatic castration-resistant prostate cancer:A systematic review

AIM： To review the defnition and performance of the commonly used end points in trials of systemic thera-pies in metastatic castration-resistant prostate cancer patients. METHODS： A literature search was undertaken on PubMed database to identify studies meeting estab-lished criteria, with the aim of selecting randomized clinical trials and study definition and performance of their end points. The end points were grouped into three categories： overall survival （OS）, time-to-event end points, and response end points. A special analysis was performed for secondary end points of the studies which documented a beneft in OS in the experimental arm. Finally, publishes analyses for surrogacy of the in-cluded end points were also reported. RESULTS： OS, time-to-event and response end points in 31 selected trials were analyzed. OS was the pri-mary end point in 14 trials, and the secondary end point in 17. A time-to-event end point was the primaryend point in 8 studies, and the secondary end point in 22; the most reported time-to-event end points were composite end points, and the events changed among trials. A response end point was the primary end point in 9 studies, in 3 it was prostate-specifc antigen （PSA）-related, in 3 pain-related and in 3 mixed. A response end point was the secondary end point in 19 studies： PSA response and radiologic response were the most frequently used secondary end points in 19 and 11 tri-als, respectively, while pain response was used in 5 studies.CONCLUSION： A homogeneous defnition of progres-sion in future trials is mandatory. Among response end points, pain-response and PSA-response appear to be the most reliable.

Prostate Cancer, Castration-Resistant Prostate Cancer (CRPC), Radium-223 Dichloride Injection for Bone Metastasized Prostate Cancer

Purpose: The purpose of this paper is to discuss the most important facts about prostate cancer, its treatments and efficacy, the type of prostate cancer that does not improve with hormonal therapy (Castration-Resistant Prostate Cancer-CRPC), and the recently approved Radium-223 dichloride targeted therapy for CRPC that has metastasized to bones. Prostate cancer is the third most common malignancy diagnosed worldwide and the most common malignant disease in men. Also, the incidence of prostate cancer varies between regions. So it’s important to have a proper understanding of all above points to prevent the further development and spread of cancer and improve the cure rate. Design: The paper begins by discussing what prostate cancer is, the risk factors, clinical manifestations, and the treatments for prostate cancer. It covers the clinical manifestations, pathology, screening (cancer biomarker Prostate Specific Antigen, Digital Rectal Examination—DRE, prostate biopsy, and imaging) and treatments for prostate cancer. The paper then delves into the main treatment methods for prostate cancer, including how Castration-Resistant Prostate Cancer (CRPC) differs from normal prostate cancer after hormone suppression therapy. Additionally, it discusses the effectiveness of the recently introduced Radium-223 dichloride injection as a radiation-targeted therapy for treating CRPC that has metastasized to bones. This section covers the properties of radium-223 dichloride injection, its pharmacokinetics, pharmacodynamics, absorption and volume of distribution, half-life, metabolism, route of elimination, clearance, toxicity, adverse effects, and mechanism of action at the tumor site. It also discusses preclinical studies related to radium-223 dichloride injection and its effectiveness in treating CRPC patients with bone metastasis. Conclusion: Prostate cancer is a common cancer that can be treated with surgery or hormonal therapy. However, if the cancer progresses despite hormonal therapy, Radium-223 dichloride injection can be used as a radiation target therapy to treat patients with CRPC and symptomatic bone metastases. This treatment kills tumor cells in bones and reduces associated pain with minimal damage to surrounding normal tissue. However, the metastatic disease cannot be cured and can only offer palliation for the patient. Suggestions: Based on the facts, Radium-223 target therapy is effective in treating and providing palliation for cancers. It is suggested to further develop the usage of radiation target therapy and to test the safety and efficacy of more than 6 injections of Radium-223 dichloride and its combination with currently used chemotherapy drugs for bone metastasized CRPC. This paper aims to contribute to future research designs related to cancer therapies using radiation and to design new studies and practical implementations, especially regarding the usage of radium-223 dichloride.

Comprehensive treatment for metastatic castration-resistant prostate cancer with neuroendocrine differentiation:a case report

Retrospective analysis of the progression of a case of metastatic castration-resistant prostate cancer with neuroendocrine differentiation:the patient was a 65 year old man with prostate adenocarcinoma on prostate biopsy,Gleason 4+4 score=8,70%,ISUP4 group,localized invasion of nerves.Progressed to metastatic castration-resistant prostate cancer after 8 months of novel endocrine therapy,persistent elevated PSA after endocrine therapy,chemotherapy,and radiation,abdominal metastasis,brain metastasis,gastric metastasis,and staging as neuroendocrine differentiation after second prostate biopsy,which is a highly malignant subtype and has been concerned as a mechanism of resistance to targeted therapies.We discuss how to choose a more optimal treatment plan and outline the patient's diagnostic and therapeutic course.We provide a reflection for the clinical study of metastatic castration-resistant prostate cancer with neuroendocrine type.

Abrogation of Hn RNP L enhances anti-PD-1 therapy efficacy via diminishing PD-L1 and promoting CD8^(+) T cell-mediated ferroptosis in castration-resistant prostate cancer

Owing to incurable castration-resistant prostate cancer(CRPC)ultimately developing after treating with androgen deprivation therapy(ADT),it is vital to devise new therapeutic strategies to treat CRPC.Treatments that target programmed cell death protein 1(PD-1)and programmed death ligand-1(PD-L1)have been approved for human cancers with clinical benefit.However,many patients,especially prostate cancer,fail to respond to anti-PD-1/PD-L1 treatment,so it is an urgent need to seek a support strategy for improving the traditional PD-1/PD-L1 targeting immunotherapy.In the present study,analyzing the data from our prostate cancer tissue microarray,we found that PD-L1 expression was positively correlated with the expression of heterogeneous nuclear ribonucleoprotein L(Hn RNP L).Hence,we further investigated the potential role of Hn RNP L on the PD-L1 expression,the sensitivity of cancer cells to T-cell killing and the synergistic effect with anti-PD-1 therapy in CRPC.Indeed,Hn RNP L knockdown effectively decreased PD-L1 expression and recovered the sensitivity of cancer cells to T-cell killing in vitro and in vivo,on the contrary,Hn RNP L overexpression led to the opposite effect in CRPC cells.In addition,consistent with the previous study,we revealed that ferroptosis played a critical role in T-cell-induced cancer cell death,and Hn RNP L promoted the cancer immune escape partly through targeting YY1/PD-L1 axis and inhibiting ferroptosis in CRPC cells.Furthermore,Hn RNP L knockdown enhanced antitumor immunity by recruiting infiltrating CD8^(+)T cells and synergized with anti-PD-1 therapy in CRPC tumors.This study provided biological evidence that Hn RNP L knockdown might be a novel therapeutic agent in PD-L1/PD-1 blockade strategy that enhanced anti-tumor immune response in CRPC.

Understanding prostate-specific antigen dynamics in monitoring metastatic castration-resistant prostate cancer： implications for clinical practice

Availability of novel hormonal therapies as well as docetaxel and cabazitaxel treatment for metastatic castration-resistant prostate cancer （CRPC） has changed the outlook for this group of patients with improvements in progression-free survival and overall survival. Physicians often diagnose the progression of prostate cancer using serum prostate-specific antigen （PSA）. However, serum PSA is not always correlated with the clinical status in CRPC. To evaluate the PSA dynamics with greater precision, understanding of the control of PSA and of the mechanisms of development of CRPC is needed. Moreover, it is necessary to use new hormonal therapies with an appropriate timing to optimally improve the prognosis and the QOL of the patients. In the present review, we ascertain the PSA dynamics and the mechanisms of the development of CRPC to assist in optimal utilization of the new treatments for mCRPC.

Prior switching to a second-line nonsteroidal antiandrogen does not impact the therapeutic efficacy of abiraterone acetate in patients with metastatic castration-resistant prostate cancer： a real-world retrospective study

Even in the era of novel targeted agents, switching to a second-line nonsteroidal antiandrogen （NSAA） is still widely used in treating metastatic castration-resistant prostate cancer （mCRPC）, especially in undeveloped countries. However, whether prior treatment with a second-line NSAA would impact the efficacy of abiraterone acetate （Abi） remains uncertain, in the current study, 87 mCRPC patients treated with Abi were analyzed. Among them, 21 were treated with a second-line NSAA （from bicalutamide to flutamide） before receiving abiraterone, while the remaining 66 received Abi directly. Therapeutic efficacy of Abi was compared between those with and without prior second-line NSAA using Kaplan-Meier curves, log-rank test, and Cox regression models. The therapeutic efficacy of Abi was similar between those with or without the prior switching treatment of flutamide, in terms of either prostate-specific antigen progression-free survival （PSA-PFS, 5.5 vs 5.6 months, P = 0.967）, radiographic progression-free survival （rPFS, 12.8 vs 13.4 months, P = 0.508）, overall survival （OS, not reached vs 30.6 months, P = 0.606）, or PSA-response rate （71.4% [15121] vs 60.6% [40166], P = 0.370）. This is the first time that the impact of prior switching of treatment to a second-line NSAA on the efficacy of Abi in mCRPC patients has been addressed. Our data support that, use of prior sequential bicalutamide and flutamide does not seem to preclude response to abiraterone, although larger cohort studies and, ideally, a randomized controlled trial are needed. These findings will facilitate doctors＇ decision-making in the treatment of mCRPC patients, especially for those with previous experience of switching NSAA second-line treatments in the clinic.

Targeting castration-resistant prostate cancer with a novel RORγ antagonist elaiophylin

Prostate cancer(PCa)patients who progress to metastatic castration-resistant PCa(mCRPC)mostly have poor outcomes due to the lack of effective therapies.Our recent study established the orphan nuclear receptor RORγas a novel therapeutic target for CRPC.Here,we reveal that elaiophylin(Elai),an antibiotic from Actinomycete streptomyces,is a novel RORy antagonist and showed potent antitumor activity against CRPC in vitro and in vivo.We demonstrated that Elai selectively binded to RORy protein and potently blocked RORγtranscriptional regulation activities.Structure-activity relationship studies showed that Elai occupied the binding pocket with several key interactions.Furthermore,Elai markedly reduced the recruitment of RORγto its genomic DNA response element(RORE),suppressed the expression of RORγtarget genes AR and AR variants,and significantly inhibited PCa cell growth.Importantly,Elai strongly suppressed tumor growth in both cell line based and patient-derived PCa xenograft models.Taken together,these results suggest that Elai is novel therapeutic RORγinhibitor that can be used as a drug candidate for the treatment of human CRPC.

Prognostic value of ECOG performance status and Gleason score in the survival of castration-resistant prostate cancer:a systematic review

Eastern Cooperative Oncology Group(ECOG)performance status and Gleason score are commonly investigated factors for overall survival(OS)in men with castration-resistant prostate cancer(CRPC).However,there is a lack of consistency regarding their prognostic or predictive value for OS.Therefore,we performed this meta-analysis to assess the associations of ECOG performance status and Gleason score with OS in CRPC patients and compare the two markers in patients under different treatment regimens or with different chemotherapy histories.A systematic literature review of monotherapy studies in CRPC patients was conducted in the PubMed database until May 2019.The data from 8247 patients in 34 studies,including clinical trials and real-world data,were included in our meta-analysis.Of these,twenty studies reported multivariate results and were included in our main analysis.CRPC patients with higher ECOG performance statuses(≥2)had a significantly increased mortality risk than those with lower ECOG performance statuses(<2),hazard ratio(HR):2.10,95%confidence interval(CI):1.68-2.62,and P<0.001.The synthesized HR of OS stratified by Gleason score was 1.01,with a 95%CI of 0.62-1.67(Gleason score≥8 vs<8).Subgroup analysis showed that there was no significant difference in pooled HRs for patients administered taxane chemotherapy(docetaxel and cabazitaxel)and androgen-targeting therapy(abiraterone acetate and enzalutamide)or for patients with different chemotherapy histories.ECOG performance status was identified as a significant prognostic factor in CRPC patients,while Gleason score showed a weak prognostic value for OS based on the available data in our meta-analysis.

Indirect comparison between abiraterone acetate and enzalutamide for the treatment of metastatic castration-resistant prostate cancer： a systematic review

This study was designed to evaluate the efficacy, tolerability, and sequential administration of abiraterone acetate （AA） and enzalutamide （Enz） for metastatic castration-resistant prostate cancer （mCRPC）. A literature search was performed with PubMed, Embase, and Web of Science databases to identify relevant studies. Reviewed literature included published phase III trials of AA or Enz in mCRPC and studies regarding their sequential administration. Given the difference in control arms in AA （active comparator） and Enz （true placebo） randomized phase III studies, indirect comparisons between AA and Enz in mCRPC showed no statistically significant difference in overall survival in prechemotherapy and postchemotherapy settings （HR. 0.90, 95% CI, 0.73-1.11; HR： 0.85, 95% CI, 0.68-1.07）. Compared with AA, Enz may better outperform control arms in treating mCRPC both before and after chemotherapy regarding secondary endpoints based on indirect comparisons： time to prostate-specific antigen （PSA） progression （HR. 0.34, 95% CI, 0.28-0.42; HR： 0.40, 95% CI, 0.30-0.53）, radiographic progression-free survival （HR： 0.37, 95% CI, 0.28-0.48; HR： 0.61, 95% CI, 0.50-0.74）, and PSA response rate （OR： 18.29, 95% CI, 11.20-29.88; OR： 10.69, 95% CI, 3.92-29.20）. With regard to the effectiveness of Enz following AA or AA following Enz, recent retrospective case series reported overall survival and secondary endpoints for patients with mCRPC progression after chemotherapy. However, confirmatory head-to-head trials are necessary to determine the optimal sequencing of these agents.