Androgen receptor gene status in plasma DNA associates with worse outcome on enzalutamide or abiraterone for castration-resistant prostate cancer: a multi-institution correlative biomarker study
TL;DR: Plasma AR status assessment using ddPCR identifies CRPC with worse outcome to enzalutamide or abiraterone and Prospective evaluation of treatment decisions based on plasma AR is now required.
About: This article is published in Annals of Oncology.The article was published on 2017-07-01 and is currently open access. It has received 214 citations till now. The article focuses on the topics: Enzalutamide & Prostate cancer.
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TL;DR: This large analysis integrating mCRPC genomics with histology and clinical outcomes identifies RB1 genomic alteration as a potent predictor of poor outcome, and is a community resource for further interrogation of clinical and molecular associations.
Abstract: Heterogeneity in the genomic landscape of metastatic prostate cancer has become apparent through several comprehensive profiling efforts, but little is known about the impact of this heterogeneity on clinical outcome. Here, we report comprehensive genomic and transcriptomic analysis of 429 patients with metastatic castration-resistant prostate cancer (mCRPC) linked with longitudinal clinical outcomes, integrating findings from whole-exome, transcriptome, and histologic analysis. For 128 patients treated with a first-line next-generation androgen receptor signaling inhibitor (ARSI; abiraterone or enzalutamide), we examined the association of 18 recurrent DNA- and RNA-based genomic alterations, including androgen receptor (AR) variant expression, AR transcriptional output, and neuroendocrine expression signatures, with clinical outcomes. Of these, only RB1 alteration was significantly associated with poor survival, whereas alterations in RB1, AR, and TP53 were associated with shorter time on treatment with an ARSI. This large analysis integrating mCRPC genomics with histology and clinical outcomes identifies RB1 genomic alteration as a potent predictor of poor outcome, and is a community resource for further interrogation of clinical and molecular associations.
712 citations
Cites background or result from "Androgen receptor gene status in pl..."
...Among these are the presence of neuroendocrine or small-cell characteristics in tumors, sometimes referred to as aggressive variant prostate cancer or neuroendocrine prostate cancer (7–9), the detection of androgen receptor (AR) splice variant 7 in circulating tumor cells (10, 11), and the presence of genomic alterations in TP53, RB1, DNA repair genes, AR, and PI3K pathway genes in circulating tumor DNA (12, 13)....
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...We confirmed a high frequency of genomic alterations in AR, namely amplifications and mutations, consistent with prior reports (5, 12) (Fig....
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TL;DR: Interventions added to androgen-deprivation therapy in men with metastatic prostate cancer have recently been noted to increase survival.
Abstract: Metastatic Prostate Cancer Interventions added to androgen-deprivation therapy in men with metastatic prostate cancer have recently been noted to increase survival. Decisions about which treatments to use and in what order to maximize the benefit should be made on the basis of high-quality clinical trials.
359 citations
TL;DR: Although detection of AR amplifications did not outperform standard prognostic biomarkers, AR gene structural rearrangements truncating the ligand binding domain were identified in several patients with primary resistance and suggest that liquid biopsy analysis can guide the use of AR-targeted therapy in general practice.
Abstract: Primary resistance to androgen receptor (AR)-directed therapies in metastatic castration-resistant prostate cancer (mCRPC) is poorly understood. We randomized 202 patients with treatment-naive mCRPC to abiraterone or enzalutamide and performed whole-exome and deep targeted 72-gene sequencing of plasma cell-free DNA prior to therapy. For these agents, which have never been directly compared, time to progression was similar. Defects in BRCA2 and ATM were strongly associated with poor clinical outcomes independently of clinical prognostic factors and circulating tumor DNA abundance. Somatic alterations in TP53, previously linked to reduced tumor dependency on AR signaling, were also independently associated with rapid resistance. Although detection of AR amplifications did not outperform standard prognostic biomarkers, AR gene structural rearrangements truncating the ligand binding domain were identified in several patients with primary resistance. These findings establish genomic drivers of resistance to first-line AR-directed therapy in mCRPC and identify potential minimally invasive biomarkers.Significance: Leveraging plasma specimens collected in a large randomized phase II trial, we report the relative impact of common circulating tumor DNA alterations on patient response to the most widely used therapies for advanced prostate cancer. Our findings suggest that liquid biopsy analysis can guide the use of AR-targeted therapy in general practice. Cancer Discov; 8(4); 444-57. ©2018 AACR.See related commentary by Jayaram et al., p. 392This article is highlighted in the In This Issue feature, p. 371.
345 citations
Cites result from "Androgen receptor gene status in pl..."
...Nevertheless, AR amplifications were associated with shorter TTP in univariate analyses, with a hazard ratio similar to that identified in a recent study leveraging droplet digital PCR to examine plasma cfDNA AR amplification status in first-line mCRPC (4)....
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TL;DR: This work discusses advances in noncastrate disease states, identification of biomarkers for prognosis and treatment selection, and opportunities in locoregional therapy to delay androgen deprivation therapy.
Abstract: The therapeutic landscape of prostate cancer has been transformed over the last decade by new therapeutics, advanced functional imaging, next-generation sequencing, and better use of existing therapies in early-stage disease. Until 2004, progression on androgen deprivation therapy for metastatic disease was treated with the addition of secondary hormonal manipulation; in the last decade, six systemic agents have been approved for the treatment of castration-resistant prostate cancer. We review clinical trials and survival benefit for these therapies and assess how the understanding of the disease shifted as these therapies were developed. We also discuss advances in noncastrate disease states, identification of biomarkers for prognosis and treatment selection, and opportunities in locoregional therapy to delay androgen deprivation therapy.
340 citations
TL;DR: It is demonstrated that AR-V7 protein is rarely expressed in primary PC but is frequently detected following androgen deprivation therapy, with further significant increase in expression following abiraterone acetate or enzalutamide therapy, which provides impetus to develop therapies that abrogate AR-v7 signaling.
Abstract: BACKGROUND. Liquid biopsies have demonstrated that the constitutively active androgen receptor splice variant-7 (AR-V7) associates with reduced response and overall survival from endocrine therapies in castration-resistant prostate cancer (CRPC). However, these studies provide little information pertaining to AR-V7 expression in prostate cancer (PC) tissue. METHODS. Following generation and validation of a potentially novel AR-V7 antibody for IHC, AR-V7 protein expression was determined for 358 primary prostate samples and 293 metastatic biopsies. Associations with disease progression, fulllength androgen receptor (AR-FL) expression, response to therapy, and gene expression were determined. RESULTS. We demonstrated that AR-V7 protein is rarely expressed (<1%) in primary PC but is frequently detected (75% of cases) following androgen deprivation therapy, with further significant (P = 0 .020) increase in expression following abiraterone acetate or enzalutamide therapy. In CRPC, AR-V7 expression is predominantly (94 degrees/n of cases) nuclear and correlates with AR-FL expression (P <= 0.001) and AR copy number (P = 0.026). However, dissociation of expression was observed, suggesting that mRNA splicing remains crucial for AR-V7 generation. AR-V7 expression was heterogeneous between different metastases from a patient, although AR-V7 expression was similar within a metastasis. Moreover, AR-V7 expression correlated with a unique 59-gene signature in CRPC, including HOXB13, a critical coregulator of AR-V7 function. Finally, AR-V7-negative disease associated with better prostate-specific antigen (PSA) responses (100% vs. 54%, P = 0.03) and overall survival (74.3 vs. 25.2 months, hazard ratio 0.23 [0.07-0.79], P = 0.02) from endocrine therapies (pre-chemotherapy). CONCLUSION. This study provides impetus to develop therapies that abrogate AR-V7 signaling to improve our understanding of AR-V7 biology and to confirm the clinical significance of AR-V7.
247 citations
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TL;DR: Copyright (©) 1999–2012 R Foundation for Statistical Computing; permission is granted to make and distribute verbatim copies of this manual provided the copyright notice and permission notice are preserved on all copies.
Abstract: Copyright (©) 1999–2012 R Foundation for Statistical Computing. Permission is granted to make and distribute verbatim copies of this manual provided the copyright notice and this permission notice are preserved on all copies. Permission is granted to copy and distribute modified versions of this manual under the conditions for verbatim copying, provided that the entire resulting derived work is distributed under the terms of a permission notice identical to this one. Permission is granted to copy and distribute translations of this manual into another language, under the above conditions for modified versions, except that this permission notice may be stated in a translation approved by the R Core Team.
272,030 citations
Oregon Health & Science University1, Duke University2, Memorial Sloan Kettering Cancer Center3, University of Paris-Sud4, University of Washington5, Guy's and St Thomas' NHS Foundation Trust6, Institute of Cancer Research7, University of California, Berkeley8, University Health Network9, Nippon Medical School10, Charité11, Astellas Pharma12, Université de Montréal13, Harvard University14, University of Alberta15, Cliniques Universitaires Saint-Luc16
TL;DR: Enzalutamide significantly decreased the risk of radiographic progression and death and delayed the initiation of chemotherapy in men with metastatic prostate cancer.
Abstract: BACKGROUND: Enzalutamide is an oral androgen-receptor inhibitor that prolongs survival in men with metastatic castration-resistant prostate cancer in whom the disease has progressed after chemotherapy. New treatment options are needed for patients with metastatic prostate cancer who have not received chemotherapy, in whom the disease has progressed despite androgen-deprivation therapy. METHODS: In this double-blind, phase 3 study, we randomly assigned 1717 patients to receive either enzalutamide (at a dose of 160 mg) or placebo once daily. The coprimary end points were radiographic progression-free survival and overall survival. RESULTS: The study was stopped after a planned interim analysis, conducted when 540 deaths had been reported, showed a benefit of the active treatment. The rate of radiographic progression-free survival at 12 months was 65% among patients treated with enzalutamide, as compared with 14% among patients receiving placebo (81% risk reduction; hazard ratio in the enzalutamide group, 0.19; 95% confidence interval [CI], 0.15 to 0.23; P<0.001). A total of 626 patients (72%) in the enzalutamide group, as compared with 532 patients (63%) in the placebo group, were alive at the data-cutoff date (29% reduction in the risk of death; hazard ratio, 0.71; 95% CI, 0.60 to 0.84; P<0.001). The benefit of enzalutamide was shown with respect to all secondary end points, including the time until the initiation of cytotoxic chemotherapy (hazard ratio, 0.35), the time until the first skeletal-related event (hazard ratio, 0.72), a complete or partial soft-tissue response (59% vs. 5%), the time until prostate-specific antigen (PSA) progression (hazard ratio, 0.17), and a rate of decline of at least 50% in PSA (78% vs. 3%) (P<0.001 for all comparisons). Fatigue and hypertension were the most common clinically relevant adverse events associated with enzalutamide treatment. CONCLUSIONS: Enzalutamide significantly decreased the risk of radiographic progression and death and delayed the initiation of chemotherapy in men with metastatic prostate cancer. (Funded by Medivation and Astellas Pharma; PREVAIL ClinicalTrials.gov number, NCT01212991.).
2,426 citations
"Androgen receptor gene status in pl..." refers background in this paper
...However, the duration of response is variable and overall survival (OS) in unselected patients is modest despite some patients having responses that last several years [1, 2]....
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University of California, San Francisco1, Harvard University2, Janssen Pharmaceutica3, University of Texas MD Anderson Cancer Center4, Université Paris-Saclay5, Autonomous University of Barcelona6, Radboud University Nijmegen7, Memorial Sloan Kettering Cancer Center8, Université de Montréal9, Katholieke Universiteit Leuven10, Hamilton Health Sciences11, VU University Amsterdam12, University of Colorado Boulder13, Duke University14, University of Washington15, National and Kapodistrian University of Athens16, University of California, Los Angeles17, University of Western Ontario18
TL;DR: Abiraterone improved radiographic progression-free survival, showed a trend toward improved overall survival, and significantly delayed clinical decline and initiation of chemotherapy in patients with metastatic castration-resistant prostate cancer.
Abstract: A b s t r ac t Background Abiraterone acetate, an androgen biosynthesis inhibitor, improves overall survival in patients with metastatic castration-resistant prostate cancer after chemotherapy. We evaluated this agent in patients who had not received previous chemotherapy. Methods In this double-blind study, we randomly assigned 1088 patients to receive abiraterone acetate (1000 mg) plus prednisone (5 mg twice daily) or placebo plus prednisone. The coprimary end points were radiographic progression-free survival and overall survival. Results The study was unblinded after a planned interim analysis that was performed after 43% of the expected deaths had occurred. The median radiographic progressionfree survival was 16.5 months with abiraterone–prednisone and 8.3 months with prednisone alone (hazard ratio for abiraterone–prednisone vs. prednisone alone, 0.53; 95% confidence interval [CI], 0.45 to 0.62; P<0.001). Over a median follow-up period of 22.2 months, overall survival was improved with abiraterone–prednisone (median not reached, vs. 27.2 months for prednisone alone; hazard ratio, 0.75; 95% CI, 0.61 to 0.93; P = 0.01) but did not cross the efficacy boundary. Abiraterone–predni sone showed superiority over prednisone alone with respect to time to initiation of cytotoxic chemotherapy, opiate use for cancer-related pain, prostate-specific antigen progression, and decline in performance status. Grade 3 or 4 mineralocorticoid-related adverse events and abnormalities on liver-function testing were more common with abiraterone–prednisone. Conclusions Abiraterone improved radiographic progression-free survival, showed a trend toward improved overall survival, and significantly delayed clinical decline and initiation of chemotherapy in patients with metastatic castration-resistant prostate cancer. (Funded by Janssen Research and Development, formerly Cougar Biotechnology; ClinicalTrials.gov number, NCT00887198.)
2,315 citations
"Androgen receptor gene status in pl..." refers background in this paper
...However, the duration of response is variable and overall survival (OS) in unselected patients is modest despite some patients having responses that last several years [1, 2]....
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TL;DR: In this article, the androgen-receptor splice variant 7 (AR-V7) was found to be associated with resistance to enzalutamide and abiraterone.
Abstract: Background The androgen-receptor isoform encoded by splice variant 7 lacks the ligand-binding domain, which is the target of enzalutamide and abiraterone, but remains constitutively active as a transcription factor. We hypothesized that detection of androgen-receptor splice variant 7 messenger RNA (AR-V7) in circulating tumor cells from men with advanced prostate cancer would be associated with resistance to enzalutamide and abiraterone. Methods We used a quantitative reverse-transcriptase–polymerase-chain-reaction assay to evaluate AR-V7 in circulating tumor cells from prospectively enrolled patients with metastatic castration-resistant prostate cancer who were initiating treatment with either enzalutamide or abiraterone. We examined associations between AR-V7 status (positive vs. negative) and prostate-specific antigen (PSA) response rates (the primary end point), freedom from PSA progression (PSA progression–free survival), clinical or radiographic progression–free survival, and overall survival. Resul...
2,221 citations
"Androgen receptor gene status in pl..." refers background or methods in this paper
...Data emerging after the trial was designed and initiated [7, 19, 20] led the PREMIERE Trial Management Group to additionally prioritize two alternative biomarkers for evaluation, namely AR-V7 detected in CTCs as described previously [19] and plasma AR....
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...Detection of AR splice variants in CTCs is also associated with shorter PFS and OS with enzalutamide or abiraterone [19, 29]....
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TL;DR: A high-throughput droplet digital PCR system that enables processing of ∼2 million PCR reactions using conventional TaqMan assays with a 96-well plate workflow is described that will allow researchers to explore complex genetic landscapes, discover and validate new disease associations, and define a new era of molecular diagnostics.
Abstract: Digital PCR enables the absolute quantitation of nucleic acids in a sample. The lack of scalable and practical technologies for digital PCR implementation has hampered the widespread adoption of this inherently powerful technique. Here we describe a high-throughput droplet digital PCR (ddPCR) system that enables processing of ∼2 million PCR reactions using conventional TaqMan assays with a 96-well plate workflow. Three applications demonstrate that the massive partitioning afforded by our ddPCR system provides orders of magnitude more precision and sensitivity than real-time PCR. First, we show the accurate measurement of germline copy number variation. Second, for rare alleles, we show sensitive detection of mutant DNA in a 100 000-fold excess of wildtype background. Third, we demonstrate absolute quantitation of circulating fetal and maternal DNA from cell-free plasma. We anticipate this ddPCR system will allow researchers to explore complex genetic landscapes, discover and validate new disease associat...
2,203 citations
"Androgen receptor gene status in pl..." refers background in this paper
...Greater sensitivity is obtained with higher input DNA [28] although the clinical relevance of rarer mutations is uncertain....
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