Second-Line Hormonal Therapy for Men With Chemotherapy-Naïve, Castration-Resistant Prostate Cancer: American Society of Clinical Oncology Provisional Clinical Opinion

JMJD2A promotes the development of castration-resistant prostate cancer by activating androgen receptor enhancer and inhibiting the cGAS-STING pathway

Exploring targets for inhibiting androgen receptor (AR) activity is an effective strategy for suppressing the development of castration-resistant prostate cancer (CRPC). Upregulation of histone demethylase JMJD2A activity is an important factor in increasing AR expression in CRPC. Based on our research, we found that the binding affinity between JMJD2A and AR increases in CRPC, while the level of AR histone methylation decreases and the H3K27ac level increases in the AR enhancer region. Further investigations revealed that overexpression of the histone demethylase JMJD2A increased the binding affinity between JMJD2A and AR, decreased AR histone methylation levels, upregulated H3K27ac in the AR enhancer region, and increased AR activity. Conversely, knocking down JMJD2A effectively reversed these effects. Additionally, in CRPC, JMJD2A expression was upregulated, the tumor-intrinsic immune cGAS-STING signaling pathway was suppressed, the tumor microenvironment was altered, and AR expression was upregulated. However, both knocking down JMJD2A and inhibiting the cyclic GMP-AMP synthase/stimulator of interferon genes (cGAS-STING) signaling pathway reversed these effects. In summary, our study indicates that in CRPC, JMJD2A can directly bind to AR and activate residual AR enhancers through its demethylation activity, thereby promoting AR expression. Furthermore, upregulation of JMJD2A expression inhibits the innate immune cGAS-STING signaling pathway of the tumor, leading to a decrease in antitumor immune function, and further promoting AR expression.

Pembrolizumab for metastatic castration-resistant prostate cancer: trials and tribulations

INTRODUCTION

Immunotherapies have revolutionized the management of various malignancies but have only recently been evaluated systematically in prostate cancer. Pembrolizumab, a programmed-death 1 (PD-1) blocking antibody, has been utilized in a small subset of prostate cancer patients with mismatch repair deficiency/microsatellite instability, but has now been assessed in broader populations of metastatic prostate cancer patients.

AREAS COVERED

The results of four pembrolizumab-based phase III clinical trials for metastatic castration-resistant prostate cancer (mCRPC) and metastatic hormone-sensitive prostate cancer (mHSPC) patients, including KEYNOTE-641, KEYNOTE-921, KEYNOTE-991, and KEYLYNK-010 are summarized. Programmed death-ligand 1 (PD-L1) expression, the efficacy of pembrolizumab in prostate cancer patients with certain molecular defects, and emerging pembrolizumab-based therapeutic combinations are also reviewed.

EXPERT OPINION

Pembrolizumab has not benefitted unselected metastatic prostate cancer patients when combined with chemotherapy, next-generation hormonal agents (NHA), or poly(ADP-ribose) polymerase inhibitors (PARPi). PD-L1 positivity does not predict the response to pembrolizumab in this disease. A small number of responding patients can likely be explained by rare genetic and molecular defects, and more innovative combination strategies are needed to improve outcomes in prostate cancer patients who are not sensitive to pembrolizumab. Emphasis should be placed on developing additional or alternative immuno-oncology approaches beyond classical immune checkpoint inhibition.

FOXS1 promotes prostate cancer progression through the Hedgehog/Gli1 pathway

BACKGROUND

Prostate cancer (PCa) remains the most common malignant tumor in men, and the clinical treatment still faces many challenges. Several molecular biomarkers of PCa progression have been reported, however, whether FOXS1 can serve as a new biomarker in PCa remains unknown.

METHODS

FOXS1 and Gli1 expression was assessed by RT-qPCR and western blot. The binding and regulation roles between FOXS1 and Gli1 were confirmed by Co-IP and ubiquitination assays. Cell viability, proliferation, apoptosis, migration, invasion and EMT progress were assessed through CCK-8, colony formation, flow cytometry, wound-healing, transwell and western blot assays, respectively. In vivo nude mice tumorigenesis model was also conducted to verify PCa growth.

RESULTS

FOXS1 was upregulated in the PCa TCGA dataset and cells. High FOXS1 level was correlated with PCa patients' worse tumor stage and shorter survival. FOXS1 knockdown inhibited PCa cell proliferation, invasion, migration, EMT and tumor growth while increased cell apoptosis. Furthermore, FOXS1 knockdown decreased the inactivation of Hedgehog (Hh) pathway. FOXS1 bind to Gli1 and decreased the ubiquitination of Gli1, which resulted in the upregulation of Gli1. Besides, both Gil1 overexpression and Hh signal activation reversed the suppression function of FOXS1 silencing on PCa growth and metastasis.

CONCLUSION

FOXS1 bind and stabilized Gli1 by blocking Gli1 ubiquitination, thereby activating Hh signaling to promote PCa cell growth and metastasis.

Fatal fulminant hepatitis in a patient taking abiraterone acetate: a case report

Abiraterone acetate is a steroidal inhibitor of cytochrome P450 17A1 indicated in the treatment of metastatic prostate cancer. This report examines the case of a 66-year-old patient diagnosed with prostate adenocarcinoma that had metastasized to the bones and lymph nodes. Treatment with abiraterone acetate and corticosteroid co-administration as well as LH-RH analog hormone therapy was initiated. Four and a half months later, the patient consulted for deterioration of general condition. Biologically, he developed a fulminant hepatitis of which he eventually died. An infectious or metabolic origin was ruled out. Oncological cause by either disease progression or second neoplastic process was eliminated by means of imaging. Hepatic toxicity was imputed to the treatment with abiraterone acetate. This case suggests that fulminant hepatitis on abiraterone acetate may be underestimated, and underscores the importance of regular monitoring of liver tests on this therapy.

Trigred motif 36 regulates neuroendocrine differentiation of prostate cancer via HK2 ubiquitination and GPx4 deficiency

Neuroendocrine prostate cancer (NEPC), the most lethal subtype of castration-resistant prostate cancer (PCa), may evolve from the neuroendocrine differentiation (NED) of PCa cells. However, the molecular mechanism that triggers NED is unknown. Trigred motif 36 (TRIM36), a member of the TRIM protein family, exhibits oncogenic or anti-oncogenic roles in various cancers. We have previously reported that TRIM36 is highly expressed to inhibit the invasion and proliferation of PCa. In the present study, we first found that TRIM36 was lowly expressed in NEPC and its overexpression suppressed the NED of PCa. Next, based on proteomic analysis, we found that TRIM36 inhibited the glycolysis pathway through suppressing hexokinase 2 (HK2), a crucial glycolytic enzyme catalyzing the conversion of glucose to glucose-6-phosphate. TRIM36 specifically bound to HK2 through lysine 48 (lys48)-mediated ubiquitination of HK2. Moreover, TRIM36-mediated ubiquitination degradation of HK2 downregulated the level of glutathione peroxidase 4 (GPx4), a process that contributed to ferroptosis. In conclusion, TRIM36 can inhibit glycolysis via lys48-mediated HK2 ubiquitination to reduce GPX4 expression and activate ferroptosis, thereby inhibiting the NED in PCa. Targeting TRIM36 might be a promising approach to retard NED and treat NEPC.

tRNA-Derived RNA Fragments Are Novel Biomarkers for Diagnosis, Prognosis, and Tumor Subtypes in Prostate Cancer

BACKGROUND

tRNA-derived RNA fragments (tRFs) are a novel class of small ncRNA that are derived from precursor or mature tRNAs. Recently, the general relevance of their roles and clinical values in tumorigenesis, metastasis, and recurrence have been increasingly highlighted. However, there has been no specific systematic study to elucidate any potential clinical significance for these tRFs in prostate adenocarcinoma (PRAD), one of the most common and malignant cancers that threatens male health worldwide. Here, we investigate the clinical value of 5'-tRFs in PRAD.

METHODS

Small RNA sequencing data were analyzed to discover new 5'-tRFs biomarkers for PRAD. Machine learning algorithms were used to identify 5'-tRF classifiers to distinguish PRAD tumors from normal tissues. LASSO and Cox regression analyses were used to construct 5'-tRF prognostic predictive models. NMF and consensus clustering analyses were performed on 5'-tRF profiles to identify molecular subtypes of PRAD.

RESULTS

The overall levels of 5'-tRFs were significantly upregulated in the PRAD tumor samples compared to their adjacent normal samples. tRF classifiers composed of 13 5'-tRFs achieved AUC values as high as 0.963, showing high sensitivity and specificity in distinguishing PRAD tumors from normal samples. Multiple 5'-tRFs were identified as being associated with the PRAD prognosis. The tRF score, defined by a set of eight 5'-tRFs, was highly predictive of survival in PRAD patients. The combination of tRF and Gleason scores showed a significantly better performance than the Gleason score alone, suggesting that 5'-tRFs can offer PRAD patients additional and improved prognostic information. Four molecular subtypes of the PRAD tumor were identified based on their 5'-tRF expression profiles. Genetically, these 5'-tRFs PRAD tumor subtypes exhibited distinct genomic landscapes in tumor cells. Clinically, they showed marked differences in survival and clinicopathological features.

CONCLUSIONS

5'-tRFs are potential clinical biomarkers for the diagnosis, prognosis, and classification of tumor subtypes on a molecular level. These can help clinicians formulate personalized treatment plans for PRAD patients and may have similar potential applications for other disease types.

Complexities of Prostate Cancer

Prostate cancer has a long disease history and a wide variety and uncertainty in individual patients' clinical progress. In recent years, we have seen a revolutionary advance in both prostate cancer patient care and in the research field. The power of deep sequencing has provided cistromic and transcriptomic knowledge of prostate cancer that has not discovered before. Our understanding of prostate cancer biology, from bedside and molecular imaging techniques, has also been greatly advanced. It is important that our current theragnostic schemes, including our diagnostic modalities, therapeutic responses, and the drugs available to target non-AR signaling should be improved. This review article discusses the current progress in the understanding of prostate cancer biology and the recent advances in diagnostic and therapeutic strategies.

GCN2 eIF2 kinase promotes prostate cancer by maintaining amino acid homeostasis

A stress adaptation pathway termed the integrated stress response has been suggested to be active in many cancers including prostate cancer (PCa). Here, we demonstrate that the eIF2 kinase GCN2 is required for sustained growth in androgen-sensitive and castration-resistant models of PCa both in vitro and in vivo, and is active in PCa patient samples. Using RNA-seq transcriptome analysis and a CRISPR-based phenotypic screen, GCN2 was shown to regulate expression of over 60 solute-carrier (SLC) genes, including those involved in amino acid transport and loss of GCN2 function reduces amino acid import and levels. Addition of essential amino acids or expression of 4F2 (SLC3A2) partially restored growth following loss of GCN2, suggesting that GCN2 targeting of SLC transporters is required for amino acid homeostasis needed to sustain tumor growth. A small molecule inhibitor of GCN2 showed robust in vivo efficacy in androgen-sensitive and castration-resistant mouse models of PCa, supporting its therapeutic potential for the treatment of PCa.

Functional impact of androgen‐targeted therapy on patients with castration‐resistant prostate cancer

Context

Second‐generation androgen receptor inhibitors (ARIs) extend metastasis‐free survival, prolong overall survival, and delay symptoms when added to androgen deprivation therapy for the treatment of castration‐sensitive or castration‐resistant prostate cancer (CRPC). However, ARIs may adversely impact physical and cognitive function, thereby decreasing quality of life and prognosis.

Objective

To evaluate the evidence regarding the potential effects of ARIs on physical and cognitive function and to contextualize how drug‐related adverse effects may influence treatment decisions in CRPC.

Evidence acquisition

We performed a literature search using MEDLINE from January 1998 to June 2020 using terms relating to prostate cancer, androgen deprivation, and physical and cognitive function. We selected 61 publications for analysis.

Evidence synthesis

Treatment‐induced deterioration in physical and cognitive function may impair the independence and well‐being of patients with CRPC. Patient‐reported outcomes from clinical trials of ARIs provide quantitative evidence of their impact on these domains, which appears to vary between ARIs, reflecting the different adverse event profiles of these agents. Thus, the risk of physical or cognitive dysfunction may be managed or mitigated by appropriate selection of treatment options. Studies in patients with CRPC have assessed the cognitive effects of ARIs with validated instruments, whereas quantitative analysis of the impact on physical function has been limited.

Conclusion

Several validated instruments utilized for the assessment of physical and cognitive function in clinical studies have been adapted for clinical practice; however, consensus on the standardization of these assessments is required. Future clinical studies employing validated tools may generate data on the impact of ARIs and guide treatment decisions for patients with CRPC.

Patient summary

We review the hormonal therapies used to treat men with prostate cancer and the effects they have on physical and cognitive function. We discuss how to measure these effects and how this may assist when choosing treatment.

Developing New Treatment Options for Castration-Resistant Prostate Cancer and Recurrent Disease

Prostate cancer (PCa) is a major diagnosed cancer among men globally, and about 20% of patients develop metastatic prostate cancer (mPCa) in the initial diagnosis. PCa is a typical androgen-dependent disease; thus, hormonal therapy is commonly used as a standard care for mPCa by inhibiting androgen receptor (AR) activities, or androgen metabolism. Inevitably, almost all PCa will acquire resistance and become castration-resistant PCa (CRPC) that is associated with AR gene mutations or amplification, the presence of AR variants, loss of AR expression toward neuroendocrine phenotype, or other hormonal receptors. Treating CRPC poses a great challenge to clinicians. Research efforts in the last decade have come up with several new anti-androgen agents to prolong overall survival of CRPC patients. In addition, many potential targeting agents have been at the stage of being able to translate many preclinical discoveries into clinical practices. At this juncture, it is important to highlight the emerging strategies including small-molecule inhibitors to AR variants, DNA repair enzymes, cell survival pathway, neuroendocrine differentiation pathway, radiotherapy, CRPC-specific theranostics and immune therapy that are underway or have recently been completed.

Incidence of dural metastases in castrate-resistant prostate cancer

Purpose:

The natural history and clinical manifestations of dural metastases (DM) in castrate-resistant prostate cancer (CRPC) will change with advances in new hormonal therapy. Here, we characterised the incidence, clinical presentation, and outcomes of patients with DM in a contemporary patient cohort with CRPC.

Methods:

We retrospectively reviewed our CRPC database from 2012 to 2020. The primary outcome was the diagnosis of DM, defined as metastasis to the dura mater in the brain or spine. We describe the presenting symptoms, biochemistry, radiologic findings, and therapy sequence for all DM patients. Multivariable logistic regression was performed to identify predictors of DM.

Results:

Six of the 275 patients (2.2%) with CRPC developed DM. The average age of CRPC diagnosis for patients with DM was 65.6 years. Mean patient survival was 4.5 months after the diagnosis of DM. At the time of CRPC diagnosis, patients who developed DM were significantly younger, had lower baseline haemoglobin, higher lactate dehydrogenase (LDH), and elevated alkaline phosphatase (ALP) compared to those without DM. On multivariable analysis, younger age of CRPC diagnosis was found to be a predictor for DM.

Conclusion:

The presence of neurological symptoms in the context of younger age, anaemia, and elevated baseline LDH and ALP are associated with DM in CRPC.

Level of Evidence:

4

The central role of Sphingosine kinase 1 in the development of neuroendocrine prostate cancer (NEPC): A new targeted therapy of NEPC

Background

Neuroendocrine prostate cancer (NEPC) is often diagnosed as a sub‐type from the castration‐resistant prostate cancer (CRPC) recurred from the second generation of anti‐androgen treatment and is a rapidly progressive fatal disease. The molecular mechanisms underlying the trans‐differentiation from CRPC to NEPC are not fully characterized, which hampers the development of effective targeted therapy.

Methods

Bioinformatic analyses were conducted to determine the clinical correlation of sphingosine kinase 1 (SphK1) in CRPC progression. To investigate the transcriptional regulation SphK1 and neuroendocrine (NE) transcription factor genes, both chromosome immunoprecipitation and luciferase reporter gene assays were performed. To demonstrate the role of SphK1 in NEPC development, neurosphere assay was carried out along with several biomarkers determined by quantitative PCR and western blot. Furthermore, in vivo NEPC xenograft models and patient‐derived xenograft (PDX) model were employed to determine the effect of SphK1 inhibitors and target validation.

Results

Significant prevalence of SphK1 in NEPC development is observed from clinical datasets. SphK1 is transcriptionally repressed by androgen receptor‐RE1‐silencing transcription factor (REST) complex. Furthermore, sphingosine 1‐phosphate produced by SphK1 can modulate REST protein turnover via MAPK signaling pathway. Also, decreased REST protein levels enhance the expression of NE markers in CRPC, enabling the transition to NEPC. Finally, specific SphK1 inhibitors can effectively inhibit the growth of NEPC tumors and block the REST protein degradation in PDX.

Conclusions

SphK1 plays a central role in NEPC development, which offers a new target for this lethal cancer using clinically approved SphK1 inhibitors.

Recommendations on Weight Loss and Healthy Lifestyle in Prostate Cancer Clinical Guidelines: A Systematic Review

Obesity is associated with negative prostate cancer outcomes (e.g., specific mortality, all-cause mortality, biochemical recurrence, etc.), according to the current scientific literature. Nevertheless, recommendations on weight loss and healthy lifestyles are poorly covered by clinicians. We aimed at identifying these recommendations from clinical practice guidelines (CPGs) for prostate cancer. We systematically searched MEDLINE, EMBASE, Web of Science, Scopus, guideline databases and online sources for CPGs updated from January 2015 to August 2021. The searches were independently conducted by two researchers, without language restrictions. A total of 97 prostate cancer guidelines, including 84 (86.6%) CPGs and 13 (13.4%) consensus statements, were included. Recommendations on reaching and maintaining a healthy weight or healthy lifestyles were provided by 7 (7.2%) and 13 (13.4%) documents, respectively. No differences regarding recommendations were found by type of document, year of publication or country. Our results suggest that professional societies and governments should update prostate cancer guidelines to include these recommendations for improving prostate cancer prognosis.

CircRNA circ_0006156 inhibits the metastasis of prostate cancer by blocking the ubiquitination of S100A9

Circular RNAs (circRNAs) have been demonstrated to play vital roles in cancer development and progression. However, studies on the association between circRNAs and prostate cancer (PCa) are still lacking. CircRNA sequencing of two pairs of PCa tissues and adjacent normal tissues was conducted in the present study, and qRT-PCR was performed to verify the results. Functional experiments were performed to investigate cellular functions after specific changes. Mass spectrometry analysis after RNA pull-down experiments and Co-IP assays were further conducted. Downstream target proteins were predicted via online databases and detected in vitro by Western blot analysis and in vivo by immunohistochemistry. Hsa_circ_0006156 (subsequently named circ_0006156) expresses at low levels in both PCa tissues and cells, and it significantly inhibits the migration and invasion of PCa cells. Circ_0006156 binds to and blocks the ubiquitination of S100A9. Moreover, functional assays revealed that circ_0006156 represses the malignant progression of PCa by binding to S100A9. Finally, in vivo experiments showed that circ_0006156 suppresses PCa migration and invasion by increasing S100A9, revealing circ_0006156 as a potential novel effective target for PCa treatment.

Marginal improvement in survival among patients diagnosed with metastatic prostate cancer in the second-line antiandrogen therapy era

Since 2004, multiple blockbuster drugs have been approved for men with metastatic prostate cancer. Nevertheless, it has been reported that no improvement in survival was observed between 2004 and 2009. Herein, we have analyzed the SEER database to assess the survival outcome of metastatic prostate cancer patients since 2000. The results demonstrated that there was an improvement in both overall and prostate cancer-specific survival for 4 months among men diagnosed with metastatic prostate cancer from 2010 to 2016 when compared to those in the pre-2010 period. Interestingly, this survival benefit was limited to patients with bone and visceral metastasis (M1b and M1c stages). Collectively, our observation suggests that despite the new treatment agents such as second-line antiandrogen therapies introduced in the modern era, the improvement in survival of metastatic prostate cancer patients has been surprisingly small.

Potential Targets Other Than PSMA for Prostate Cancer Theranostics: A Systematic Review

Background: Prostate-specific membrane antigen (PSMA) is not sufficiently overexpressed in a small proportion of prostate cancer (PCa) patients, who require other strategies for imaging and/or treatment. We reviewed potential targets other than PSMA for PCa theranostics in nuclear medicine that have already been tested in humans. Methods: We performed a systematic web search in the PubMed and Cochrane databases, with no time restrictions by pooling terms (“prostate cancer”, “prostatic neoplasms”) and (“radioligand”, “radiotracer”). Included articles were clinical studies. The results were synthetized by the target type. Results: We included 38 studies on six different targets: gastrin-releasing peptide receptors (GRPRs) (n = 23), androgen receptor (n = 11), somatostatin receptors (n = 6), urokinase plasminogen activator surface receptor (n = 4), fibroblast activation protein (n = 2 studies) and integrin receptors (n = 1). GRPRs, the most studied target, has a lower expression in high-grade PCa, CRPC and bone metastases. Its use might be of higher interest in treating earlier stages of PCa or low-grade PCa. Radiolabeled fibroblast activation protein inhibitors were the most recent and promising molecules, but specific studies reporting their interest in PCa are needed. Conclusion: Theranostics in nuclear medicine will continue to develop in the future, especially for PCa patients. Targets other than PSMA exist and deserve to be promoted.

Suppressing BCL-XL increased the high dose androgens therapeutic effect to better induce the Enzalutamide-resistant prostate cancer autophagic cell death

Most patients with advanced prostate cancer (PCa) initially respond well to androgen deprivation therapy (ADT) with antiandrogens, but most of them eventually become resistant to ADT. Here, we found that the antiandrogen Enzalutamide-resistant (EnzR) PCa cells can be suppressed by hyper-physiological doses of the androgen DHT. Mechanism dissection indicates that while androgens/androgen receptor (AR) can decrease BCL-2 expression to induce cell death, yet they can also simultaneously increase anti-apoptosis BCL-XL protein expression via decreasing its potential E3 ubiquitin ligase, PARK2, through transcriptionally increasing the miR-493-3p expression to target PARK2. Thus, targeting the high dose DHT/AR/miR-493-3p/PARK2/BCL-XL signaling with BCL-XL-shRNA can increase high-dose-DHT effect to better suppress EnzR cell growth via increasing the autophagic cell death. A preclinical study using in vivo mouse model also validated that suppressing BCL-XL led to enhance high dose DHT effect to induce PCa cell death. The success of human clinical trials in the future may help us to develop a novel therapy using high dose androgens to better suppress CRPC progression.

Development and validation of a six-RNA binding proteins prognostic signature and candidate drugs for prostate cancer

The dysregulation of RNA binding proteins (RBPs) regulates the progression of several cancers. However, information on the overall functions of RBPs in prostate cancer (PCa) remains largely understudied. Therefore, based on the TCGA dataset, this study identified 144 differentially expressed RBPs in tumors compared to normal tissues. Subsequently, through univariate, LASSO and multivariate Cox regression analysis, 6 RBP genes among them, MSI1, MBNL2, LENG9, REXO2, RNASE1, and PABPC1L were screened as prognostic hub genes and prognostic signature was further identified. Further analysis indicated that the high-risk group was significantly associated with poor RFS, which was validated in the MSKCC cohort. Besides, patients in the high-risk group were closely associated with dysregulation of DNA damage repair pathway, copy number alteration, tumor burden mutation, and low-response to cisplatin (P < 0.001), and bicalutamide (P < 0.001). Using the Connectivity Map, we finally predicted 3 drugs including, ribavirin, carmustine, and carbenoxolone. In summary, we identified six-RBP gene signature and 3 potential drugs against PCa, which might promote the individualized treatment strategies and further improve the quality of life among PCa patients.

Resetting the Bar of Castration Resistance - Understanding Androgen Dynamics in Therapy Resistance and Treatment Choice in Prostate Cancer

This review discusses impact of advancements in biologic understanding of prostate cancer (PCa) on definition and diagnosis of castration-resistant PCa (CRPC), predictive factors for progression to CRPC and treatment strategies. More sensitive assays confirm that bilateral orchiectomy reduces serum testosterone (T) closer to < 20 ng/dL than < 50 ng/dL, and evidence suggests that achieving T < 20 ng/dL improves outcomes and delays CRPC emergence. Regular T assessments will evaluate whether T is adequately suppressed in the setting of potential progression to CRPC, given that late dosing may result in T escape. More advanced imaging modalities and biomarker assays allow earlier detection of disease progression. Predictive factors for progression to CRPC include Gleason grade, extent of metastatic spread, germline hereditary factors such as gene mutations affecting androgen receptor amplification or DNA repair deficiency mutations, prostate-specific antigen kinetics, and biomarker analyses. Treatment options for CRPC have expanded beyond androgen deprivation therapy to include therapies that suppress T or inhibit its activity through varying mechanisms. Future directions include therapies with novel biological targets, drug combinations and personalized treatments. Advanced PCa management aims to delay progression to CRPC and prolong survival. With redefinition of castration and advancements in understanding of the biology of disease progression, diagnosis and treatment strategies should be re-evaluated. Definition of CRPC could be updated to reflect the T < 20 ng/dL requirement as this is a 'true' castrate level and may improve outcomes. It is important that androgen deprivation therapy as foundational therapy is continued even as new CRPC therapies are introduced.

Dual targeting of EZH2 and androgen receptor as a novel therapy for castration-resistant prostate cancer

Castration-resistant prostate cancer (CRPC) emerges after androgen withdrawal therapy and remains incurable due to the lack of effective treatment protocols. Treatment with enzalutamide, a second generation androgen receptor (AR) antagonist, offers an initial response followed by drug resistance and tumor relapse. Enhancer of zeste homolog 2 (EZH2), a member of PRC2 complex, is an important target that acts as a coactivator of AR-mediated gene suppression whose oncogenic activity increases during castration. We hypothesize that dual targeting of EZH2 and AR could be highly effective in CRPC treatment. The present study aimed to examine the effectiveness of combination using EZH2 inhibitor GSK126 with antiandrogen enzalutamide in the treatment of CRPC cells. Treatment of 22Rv1 and C42B CRPC cells with a combination of GSK126 and enzalutamide led to synergistic inhibition of cell proliferation, cell cycle arrest and marked increase in cell death. Mechanistically, this combination treatment significantly reduced expression of AR and AR-v7, decrease in PSA and Akt activity, diminution of EZH2 and other members of PCR2 complex including SUZ12 and EED, with simultaneous loss of H3K27 trimethylation and dissociation between AR and PRC2 complex members compared to individual treatment. This study provides preclinical proof-of-concept that combined treatment of EZH2 inhibitor with AR antagonist results in synergistic anticancer effects opening new possibilities for treatment of CRPC tumors.

The prognostic value and potential mechanism of Matrix Metalloproteinases among Prostate Cancer

Background: Matrix Metalloproteinases (MMPs) play an indispensable role in the initial alteration and development of PCa. We tried to generate an MMP-related prognostic signature (MMPS) in prostate cancer (PCa). Methods: TCGA-PRAD, MSKCC/GSE21032, GSE116918, GSE70769 cohorts were enrolled to assess the prognostic value of MMPs. The least absolute shrinkage and selection operator (LASSO) Cox regression was employed to generate the MMPS signature. The log-rank test and Kaplan-Meier (K-M) survival curve were applied to show the difference RFS, The receiver operating characteristic (ROC) curve and area under the ROC curve (AUC) was plotted to predict the accuracy of signature. CIBERSORT was conducted to analyze the different immune infiltration in MMPS-H and MMPS-L groups. Potential signaling pathways activated in the MMPS-H groups by Metascape. Results: MMP1, MMP7, MMP11, MMP24 and MMP26 were selected by LASSO regression and established the MMPS predict signature. The MMPS showed the high prognostic value in TCGA-PRAD training cohort (AUC=0.714) and validation cohorts (GSE116918: AUC=0.976, GSE70769: AUC=0.738, MSKCC: AUC=0.793). Pid integrin1 pathway, G2M checkpoint, and response to growth factor signaling pathways were activated in MMPS-H group, patients with the high MMPS risk score and low M2 macrophage showed the worst recurrence-free survival (RFS). Conclusion: MMPs involved and played an essential role in the tumorigenesis and biochemical recurrence in PCa patients. The MMPS signature could accurately predict the recurrence of PCa patients and validated in several cohorts.

Comparative study of surgical orchidectomy and medical castration in treatment efficacy, adverse effects and cost based on a large prospective metastatic prostate cancer registry

INTRODUCTION

Androgen deprivation therapy (ADT) remains the mainstay of treatment for metastatic prostate cancer (mPCa) but is associated with significant morbidities. Comparisons of medical castration (MC) and surgical orchidectomy (SO) have yielded varied results. We aimed to evaluate the oncological outcomes, adverse effect (AE) profiles and costs of MC and SO in patients with mPCa.

METHODS AND MATERIALS

We reviewed 523 patients who presented with de novo mPCa from a prospectively maintained prostate cancer database over 15 years (2001-2015). All patients received ADT (either MC or SO) within 3 months of diagnosis. The data were analyzed with chi-square, binary and logistics regression models.

RESULTS

One hundred and fifty one (28.9%) patients received SO while 372 (71.1%) patients had MC. The median age of presentation was 73 [67 -79] years old. The median prostate-specific antigen (PSA) was 280ng/ml [82.4-958]. Three hundred and thirty one patients (66.3%) had high volume bone metastasis and 57 patients (10.9%) had visceral metastasis. Clinical demographics and clinicopathological were similar across both groups. Similar oncological outcomes were observed in both groups. The proportion of PSA response (PSA <1ng/ml) was 65.6% for SO and 67.2% for MC (P = 0.212). Both therapies achieve >95% of effective androgen suppression (testosterone <50ng/dL). Time to castrate-resistance was similar (18 vs 16 months, P = 0.097), with comparative overall survival (42 vs. 38.5 months, P = 0.058) and prostate cancer mortality (80.1 vs. 75.9%, P = 0.328). Similarly, no difference was observed for the 4 AE profiles between SO and MC respectively; change in Haemoglobin (-0.75 vs. -1.0g/dL, P = 0.302), newly diagnosed Diabetes mellitus (4.6 vs. 2.9%, P = 0.281), control measured by HbA1c (0.2 vs. 0.25%, P = 0.769), coronary artery disease events (9.9 vs. 12.9%, P = 0.376) and skeletal-related fractures (9.3 vs. 7.3%, P = 0.476). After adjusting for varying governmental subsidies and inflation rates, the median cost of SO was $5275, compared to MC of $9185.80.

CONCLUSION

Both SO and MC have similar oncological outcomes and AE profiles. However, SO remains a much more cost-effective form of ADT for the long-term treatment of mPCa patients.

Targeting the PI3K/AKT Pathway Overcomes Enzalutamide Resistance by Inhibiting Induction of the Glucocorticoid Receptor

The PI3K-AKT pathway has pleiotropic effects and its inhibition has long been of interest in the management of prostate cancer, where a compensatory increase in PI3K signaling has been reported following androgen receptor (AR) blockade. Prostate cancer cells can also bypass AR blockade through induction of other hormone receptors, in particular the glucocorticoid receptor (GR). Here we demonstrate that AKT inhibition significantly decreases cell proliferation through both cytostatic and cytotoxic effects. The cytotoxic effect is enhanced by AR inhibition and is most pronounced in models that induce compensatory GR expression. AKT inhibition increases canonical AR activity and remodels the chromatin landscape, decreasing enhancer interaction at the GR gene (NR3C1) locus. Importantly, it blocks induction of GR expression and activity following AR blockade. This is confirmed in multiple in vivo models, where AKT inhibition of established xenografts leads to increased canonical AR activity, decreased GR expression, and marked antitumor activity. Overall, our results demonstrate that inhibition of the PI3K/AKT pathway can block GR activity and overcome GR-mediated resistance to AR-targeted therapy. Ipatasertib is currently in clinical development, and GR induction may be a biomarker to identify responsive patients or a responsive disease state.

Characterization of the prognostic values and response to immunotherapy/chemotherapy of Krüppel-like factors in prostate cancer

At present, the overall genetic and epigenetic effects of Krüppel‐like factors (KLFs) on prostate cancer (PCa) remain unclear. Therefore, we systematically investigated the molecular differences in KLFs of transcription expression, promoter methylation and genetic alteration. Univariate and multivariate Cox proportional hazard regression was used to analyse the effect on RFS and establish the prognostic signature in the TCGA cohort, MSKCC and GSE116918 cohorts employed to validate the signature. Biological pathway enrichment and the potential response to immunotherapy and chemotherapy were inferred. The transcription levels of most KLFs are associated with the clinical outcome of PCa. Gleason score (P = .009), pathology T stage (P = .006), KLF3 (P = .034), KLF5 (P = .002) and KLF7 (P = .035) were independent prognostic factors. A prognostic signature was established in the TCGA cohort (P < .001) and validated in the MSKCC (P < .001) and GSE116918 cohorts (P = .006). Demethylation of KLF5 by 5‐azacytidine led to increased protein levels, whereas knockdown of KLF5 promoted cell proliferation. Patients in KLF‐F were more likely to respond to immunotherapy (P < .001) and bicalutamide (P < .001). In summary, we found that the KLFs and clinical feature‐based signatures may improve prognosis prediction in PCa and further promote patient stratification and disease management.

Increased Risk of Hypertension with Enzalutamide in Prostate Cancer: A Meta-Analysis

Hypertension is associated with enzalutamide in the treatment of prostate cancer. We performed a meta-analysis of randomized clinical trials to determine the risk of hypertension. Databases including Pubmed and Google scholar were searched to identify randomized clinical trials with enzalutamide. A total of seven studies including 7347 patients were selected. The overall incidences of all-grade and high-grade hypertension were 11.9% (95%% CI: 8.8-16.0%) and 4.9% (95%% CI: 3.5-6.8%) respectively, with a relative risk of 2.82 (95%% CI: 2.34-3.38, p < 0.001) for all-grade and 2.27 (95%% CI: 1.73-2.96, p < 0.001) for high-grade. There was a significant risk of developing hypertension with enzalutamide.

Emerging therapeutic agents for genitourinary cancers

The treatment of genitourinary malignancies has dramatically evolved over recent years. Renal cell carcinoma, urothelial carcinoma of the bladder, and prostate adenocarcinoma are the most commonly encountered genitourinary malignancies and represent a heterogeneous population of cancers, in both histology and approach to treatment. However, all three cancers have undergone paradigm shifts in their respective therapeutic landscapes due to a greater understanding of their underlying molecular mechanisms and oncogenic drivers. The advance that has gained the most recent traction has been the advent of immunotherapies, particularly immune checkpoint inhibitors. Immunotherapy has increased overall survival and even provided durable responses in the metastatic setting in some patients. The early success of immune checkpoint inhibitors has led to further drug development with the emergence of novel agents which modulate the immune system within the tumor microenvironment. Notwithstanding immunotherapy, investigators are also developing novel agents tailored to a variety of targets including small-molecule tyrosine kinase inhibitors, mTOR inhibitors, and novel fusion proteins to name a few. Erdafitinib has become the first targeted therapy approved for metastatic bladder cancer. Moreover, the combination therapy of immune checkpoint inhibitors with targeted agents such as pembrolizumab or avelumab with axitinib has demonstrated both safety and efficacy and just received FDA approval for their use. We are in an era of rapid progression in drug development with multiple exciting trials and ongoing pre-clinical studies. We highlight many of the promising new emerging therapies that will likely continue to improve outcomes in patients with genitourinary malignancies.

The role of ketoconazole in current prostate cancer care

Ketoconazole is a nonselective steroid 17α-hydroxylase/17,20 lyase (CYP17A1) inhibitor that has been used, off-label, as a second-line therapy for castration-resistant prostate cancer (CRPC). The drug has shown clinical efficacy without survival benefit. Despite not improving survival, ketoconazole has beneficial characteristics, such as its low cost, a relatively favourable toxicity profile compared with chemotherapy, and its efficacy both before and after chemotherapy. The approval of several new, highly effective treatments, including abiraterone acetate, enzalutamide, and apalutamide, warrants re-evaluation of the role of ketoconazole and other classic agents in achieving the optimal timing and sequencing of available agents to prolong survival and maintain patients' quality of life. In the current CRPC treatment landscape, we believe that ketoconazole can be considered in patients with nonmetastatic CRPC and in those with metastatic CRPC who do not respond to, tolerate, or have access to chemotherapy and other standard therapeutic options.

Sequencing strategies in the new treatment landscape of prostate cancer

Over the last 10 years, a number of new agents approved for the treatment of metastatic castration-resistant prostate cancer have led to a significant improvement in overall survival. The addition of new agents to androgen deprivation therapy has also allowed a paradigmatic change in the treatment of metastatic hormone-sensitive prostate cancer by improving overall survival in comparison with androgen deprivation therapy alone. Furthermore, recent data concerning the efficacy of three different androgen receptor-targeting agents in patients with nonmetastatic castration-resistant prostate cancer have opened up new scenarios for future patients' management. Defining the best sequencing strategies for men with prostate cancer is a currently unmet medical need, and choosing treatment is often challenging for clinicians because of the lack of direct comparisons of the available agents. The aim of this paper is to provide a comprehensive review of the literature concerning current sequencing strategies for prostate cancer patients.

The establishment of immune infiltration based novel recurrence predicting nomogram in prostate cancer

Prostate cancer (PCa), a severe health burden for males, accounts for the second frequent cancer and fifth tumor specific death cancer around the world. Several studies on tumor-infiltrating immune cells (TIICs) have shown inconsistent and controversial results to PCa. We downloaded a gene expression matrix and clinical information from TCGA, and CIBERSORT was used to identify the proportion of TIICs. Wilcoxon's Sign Rank Test evaluated different gene expression levels in PCa and normal tissues. Kaplan-Meier curves were used to evaluate the associations of TIICs and recurrence-free survival (RFS). Finally, based on the preset P-value of .05, the distribution of TIICs in 73 PCa tissues and 11 normal tissues was illustrated. Activated CD4⁺ T cells and M0 macrophages account for a high proportion in PCa tissues, while neutrophils and monocytes were found at a high density in normal tissues. Further results showed that the density of plasma cells, Treg cells and resting mast cells were associated with advanced PCa. Additionally, M2 macrophages affected the RFS of PCa patients, and AR was also involved. In the current study, we first evaluated the immune infiltration among PCa and revealed that M2 macrophages could predict the prognosis of PCa patients. Meanwhile, based on the LASSO regression analysis, we established a novel nomogram to assess the recurrence risk of PCa based on immune cell proportions and clinical features.

Efficacy of Androgen Deprivation Therapy in Patients with Metastatic Castration-Resistant Prostate Cancer Receiving Docetaxel-Based Chemotherapy

PURPOSE

The purpose of this study was to determine the comparative effectiveness of androgen deprivation therapy (ADT) combined with docetaxel (DTX)-based chemotherapy in Korean and Japanese castration-resistant prostate cancer (CRPC) patient cohorts.

MATERIALS AND METHODS

Metastatic CRPC patients who underwent more than three DTX-based chemotherapy cycles in Korea and Japan between 2002 and 2017 were retrospectively analyzed and divided into the DTX-only (DTX, n=30) and combination (DTX+ADT, n=46) groups. Progression-free survival (PFS) was calculated as the time from the start of chemotherapy to the occurrence of either disease progression (prostate-specific antigen [PSA] progression or radiographic progression) or death. The primary end point was PFS and the secondary end point was overall survival (OS).

RESULTS

In the DTX and DTX+ADT groups, the median PFS was 6.0 and 11.0 months (log-rank p=0.053). The multivariate Cox regression analysis revealed that the significant predicting factors of PFS were ADT administration (hazard ratio [HR], 0.478; 95% confidence interval [CI], 0.284-0.804; p=0.005) and number of DTX-based chemotherapy cycles (HR, 0.934; 95% CI, 0.899-0.970; p<0.001). In the DTX and DTX+ADT groups, the median OS was 16.0 and 19.5 months (log-rank p=0.825). Through multiple Cox regression analysis, we found that the significant predicting factors of OS were the PSA nadir level (HR, 1.001; 95% CI, 1.000-1.002; p<0.001) and number of DTX-based chemotherapy cycles (HR, 0.932; 95% CI, 0.876-0.991; p=0.024).

CONCLUSIONS

Concurrent DTX-based chemotherapy and ADT may be beneficial compared with DTX-based chemotherapy alone in chemotherapy-naïve metastatic CRPC patients in terms of the PFS, but not the OS.

Cancer Drug Use in the Last Month of Life in Men With Castration-Resistant Prostate Cancer

PURPOSE

Several new drug therapies have been approved in CRPC in the past decade. However, little is known about their potential overuse at the end of life. Cancer therapy use at the end of life has been considered an indicator of overtreatment. The study objective was to describe CRPC drug use in the last month of life of CRPC patients in Quebec.

PATIENTS AND METHODS

Using administrative databases from the province of Quebec in Canada, we identified patients who received medical or surgical castration treatment, received one or more CRPC drugs (chemotherapy, abiraterone, or bone-targeted therapy), and died between 2001 and 2013. CRPC drug use in the last month of life was the primary outcome.

RESULTS

The cohort consisted of 1,148 patients with CRPC. A total of 316 men (27.5%) received a CRPC drug in the last month of life. For those who received chemotherapy, abiraterone, and bone-targeted therapy, 10.2%, 27.8%, and 31.8% received them in the last month of life, respectively. In multivariable analyses, age older than 75 years (odds ratio [OR], 0.75; 95% CI, 0.57 to 0.99), and prostate cancer diagnosis received less than 24 months earlier (OR, 0.43; 95% CI, 0.26 to 0.72) were associated with less CRPC drug use. Relative to dying between 2005 and 2011, dying between 2012 and 2013 (OR 1.60; 95% CI, 1.18 to 2.18) was associated with greater CRPC drug use.

CONCLUSION

More than one quarter of patients received CRPC drug therapies in the last month of life. Persistent chemotherapy, abiraterone, bone-targeted therapies, and medical castration drugs in the last month of life may be an indicator of inappropriate and expensive end-of-life care.

The Current Landscape of Treatment in Non-Metastatic Castration-Resistant Prostate Cancer

Non-metastatic castration-resistant prostate cancer (nmCRPC) is a heterogeneous disease with variable potential in developing into overt metastases. It is an area of increased unmet need in advanced prostate cancer and for which there had been no great treatments until recent US Food and Drug Administration (FDA) approval of 2 novel anti-androgens apalutamide and enzalutamide, which were both approved given benefit in metastasis-free survival. Early data on the use of darolutamide, another novel anti-androgen, are also explored. This review discusses the pivotal trials that led to the approval of apalutamide and enzalutamide in the nmCRPC setting and discusses the key promises and challenges with the use of these agents.

Phase III Trial of PROSTVAC in Asymptomatic or Minimally Symptomatic Metastatic Castration-Resistant Prostate Cancer

PURPOSE

PROSTVAC, a viral vector–based immunotherapy, prolonged median overall survival (OS) by 8.5 months versus placebo in metastatic castration-resistant prostate cancer in a phase II study. This phase III study further investigated those findings.

PATIENTS AND METHODS

Patients were randomly assigned to PROSTVAC (Arm V; n = 432), PROSTVAC plus granulocyte-macrophage colony-stimulating factor (Arm VG; n = 432), or placebo (Arm P; n = 433), stratified by prostate-specific antigen (less than 50 ng/mL v 50 ng/mL or more) and lactate dehydrogenase (less than 200 v 200 U/L or more). Primary end point was OS. Secondary end points were patients alive without events (AWE)—namely, radiographic progression, pain progression, chemotherapy initiation, or death—at 6 months and safety. The study design was a superiority trial of PROSTVAC (Arm V or Arm VG) versus Arm P. Three interim analyses were planned.

RESULTS

At the third interim analysis, criteria for futility were met and the trial was stopped early. Neither active treatment had an effect on median OS (Arm V, 34.4 months; hazard ratio, 1.01; 95% CI, 0.84 to 1.20; P = .47; Arm VG, 33.2 months; hazard ratio, 1.02; 95% CI, 0.86 to 1.22; P = .59; Arm P, 34.3 months). Likewise, AWE at 6 months was similar (Arm V, 29.4%; odds ratio, 0.96; 95% CI, 0.71 to 1.29; Arm VG, 28.0%; odds ratio, 0.89; 95% CI, 0.66 to 1.20; placebo, 30.3%). Adverse events were similar for the treatment and placebo groups, with the most common being injection site reactions (62% to 72%) and fatigue (21% to 24%). Arrhythmias were the most common cardiac-related events (1.4% to 3.5%). There were no reports of either myocarditis or pericarditis. Serious treatment-related events occurred in less than 1% of all patients.

CONCLUSION

Whereas PROSTVAC was safe and well tolerated, it had no effect on OS or AWE in metastatic castration-resistant prostate cancer. Combination therapy is currently being explored in clinical trials.

Programmed death ligand 1 expression in prostate cancer cells is associated with deep changes of the tumor inflammatory infiltrate composition

BACKGROUND

The main aim of this study was to investigate the putative correlation between the composition of intratumoral inflammatory infiltrate and the expression of programmed death ligand 1 (PD-L1) by prostate cancer cells. In addition, we evaluated the correlation between the expression of PD-L1 and PTX3.

METHODS

We enrolled 100 patients from which we collected one surgical sample each. Paraffin serial sections were obtained to perform histological classifications and tissues microarray construction. Serial tissues microarray paraffin sections were also used for PD-L1 analysis and intratumoral inflammatory infiltrate characterization (CD4, CD8, CD57, CD3, PD1, PSGL-1, TIGIT, CD20, CD38, CD68, CD163, and PTX3) by immunohistochemistry .

RESULTS

Our result showed a significant increase of the number of both PD-L1 and PTX3 positive cells in prostate tumors respect to benign lesions. Inflammatory infiltrate of PD-L1 positive prostate cancer lesions was characterized by a decrease of both PD1 positive lymphocytes and tumor-infiltrated macrophages, mainly M2 subpopulation. Also, PTX3 expression showed an inverse correlation with the number of PD-L1 positive prostate cancer cells.

CONCLUSIONS

If confirmed, our data could be useful to predict the variations of the inflammatory population related to PD-L1 expression in prostate cancer. This can lay the foundation to establish therapeutic protocols able to inhibit the PD-L1 activity and, at the same time, to reactivate the antitumor inflammatory process.

Modification of American Joint Committee on cancer prognostic groups for renal cell carcinoma

Background

To compare the predictive value of the current AJCC stage grouping for renal cell carcinoma (RCC) to our modifications.

Patients and methods

A total of 2120 patients with RCC from Fudan University Shanghai Cancer Center (FUSCC) database and 74 506 counterparts from SEER database were included. Cox regression was used to calculate the relative impacts between prognostic groups. The predictive accuracy of overall survival (OS) was assessed using the concordance index (C‐index), which was compared by likelihood ratio test.

Results

In FUSCC cohort, the 5‐year‐OS rate for T3N0M0 patients was higher than T1‐3N1M0 (72.7% vs 38.1%). The 5‐year‐OS rate for T4N0M0 was 36.2%, which was close to T1‐3N1M0 but not to T4N1M0 (0%) and TanyNanyM1 (12.6%). The elements of AJCC groups were regrouped according to the ranks of hazard ratios. The modified stages II (T3N0M0), III (T1‐3N1M0, T4N0M0), and IV (T4N1M0, TanyNanyM1) exhibited greater survival stratification than AJCC groups. The modifications were validated in SEER cohort and yielded similar survival outcomes. The predictive accuracy of OS in modified prognostic groups was significantly higher than AJCC groups in stages II‐IV subgroups in both FUSCC (C‐index: 0.801 vs 0.779, P < 0.001) and SEER cohort (C‐index: 0.770 vs 0.764, P < 0.001).

Conclusions

The modified AJCC prognostic groups for RCC provided significantly improved survival prediction compared with the 8th AJCC edition. A precise risk stratification of modified stages II‐IV disease provides an important basis for risk‐equivalent treatment recommendation.

Role of the androgen signaling axis in genitourinary malignancies

As we learn more about the molecular biology of genitourinary malignancies, novel therapeutic strategies can be developed. This is especially crucial for prostate, renal, and bladder cancer, where mortality rates remain high especially in advanced disease states. The androgen signaling axis and the androgen receptor (AR) are areas that are actively being explored for their role in these diseases. Although long been associated with prostate cancer development and progression, the role of AR in renal cell carcinoma (RCC) and bladder cancer is becoming recognized as well. This review will highlight the current research into the role of the androgen signaling axis in genitourinary malignancies and how this pathway is being used to expand our therapeutic armamentarium.

Effectiveness and tolerability of targeted drugs for the treatment of metastatic castration-resistant prostate cancer: a network meta-analysis of randomized controlled trials

PURPOSE

Castration-resistant prostate cancer (CRPC) refers to prostate cancer that has progressed after initial androgen deprivation therapy (ADT). Over the years, treatment strategies for metastatic CRPC (mCRPC) have undergone considerable changes. We performed a network meta-analysis to assess the effectiveness and tolerability of targeted agents for mCRPC.

METHODS

We search databases including MEDLINE, EMBASE, and the Cochrane Library through Sep 5, 2017. The major effectiveness outcomes were progression-free survival (PFS) and overall survival (OS). The tolerability outcome was severe adverse events (AEs) of grade ≥ 3.

RESULTS

Twenty-six articles assessing a total of 20,314 patients were included in this study. A random-effect analysis showed that targeted agents could significant prolong PFS in mCRPC patients (I² = 94.3%; hazard ratio (HR): 0.74; 95% confidence interval (CI): 0.65-0.84; p < 0.001). In addition, the surface under the cumulative ranking curve (SUCRA) ranking from the network analysis showed that enzalutamide was the most effective in improving the PFS of mCRPC patients (100%), followed by abiraterone (90.1%) and tasquinimod (84.2%). Additionally, targeted agents could clearly prolong OS in mCRPC patients (I² = 71.6%; HR: 0.91; 95% CI: 0.85-0.97; p < 0.001). Furthermore, based on SUCRA ranking, enzalutamide was the most effective in improving the OS of mCRPC patients (97.2%), followed by abiraterone (91.1%) and zibotentan (65.8%). Intetumumab was associated with the lowest incidence of severe AEs (94.9%), followed by atrasentan (85.1%) and placebo (79.3%).

CONCLUSION

In patients with mCRPC, enzalutamide, abiraterone and tasquinimod can prolong PFS, and enzalutamide and abiraterone can prolong OS. Additionally, enzalutamide and abiraterone can improve both PFS and OS with a low risk of causing severe AEs.

Baseline prostate-specific antigen levels following treatment with abiraterone acetate as a prognostic factor in castration-resistant prostate cancer

The aim of the present study was to investigate the prognostic factors associated with progression-free survival (PFS) and overall survival (OS) times in patients with castration-resistant prostate cancer (CRPC) who received treatment with abiraterone acetate (AA) in routine clinical settings. A total of 93 patients treated with AA between September 2014 and February 2017 were selected and their medical records were analyzed retrospectively. The median PFS time of docetaxel (DTX)-naïve patients was 171 days, and that of post-DTX patients was 56 days. The OS time of DTX-naïve patients did not reach the median. The median OS time of post-DTX patients was 761 days. Multivariate analyses identified baseline prostate-specific antigen (PSA) level prior to treatment with AA and the PSA response rate as independent prognostic factors for PFS time, and baseline PSA prior to treatment with AA as the only independent prognostic factor for OS time. The results of the present study indicate that the baseline PSA level prior to treatment with AA is a notable prognostic factor in patients with CRPC.

Androgen deprivation therapy for the treatment of prostate cancer: a focus on pharmacokinetics

INTRODUCTION

Medical therapy has undergone many changes as our understanding of prostate cancer cell biology has improved. Androgen deprivation therapy (ADT) remains the mainstay of therapy for metastatic disease. Metastatic castrate-resistant prostate cancer (CRPC) is an important concern since we are unable to stop progression with currently available agents. Areas covered: Pharmacologic ADT is the most commonly used treatment for metastatic prostate cancer. Multiple agents are available for both first-line and second-line use: antiandrogens, estrogens, luteinizing hormone-releasing hormone agonists/antagonists, and CYP17 inhibitors. With adoption of these drugs, it is important to consider their pharmacokinetic and pharmacodynamic properties. Many undergo metabolism through cytochrome P450. Levels may be altered with co-administration of drugs acting as enzyme inhibitors or inducers. Understanding mechanism of action, metabolism, and excretion of these drugs allows clinicians to provide the best therapeutic care while minimizing adverse events. Expert opinion: Many men with metastatic prostate cancer will progress to castration resistance. An understanding of resistance mechanisms at the cellular level has revealed new drug targets with hopes of halting or reversing progression of metastatic disease. Second-line agents, traditionally reserved for CRPC, are being studied in metastatic castrate-sensitive prostate cancer, and may offer practice-changing evidence supporting their use.