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Wüstmann N, Seitzer K, Humberg V, Vieler J, Grundmann N, Steinestel J, Tiedje D, Duensing S, Krabbe LM, Bögemann M, Schrader AJ, Bernemann C, Schlack K. Co-expression and clinical utility of AR-FL and AR splice variants AR-V3, AR-V7 and AR-V9 in prostate cancer. Biomark Res 2023; 11:37. [PMID: 37016463 PMCID: PMC10074820 DOI: 10.1186/s40364-023-00481-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2022] [Accepted: 03/28/2023] [Indexed: 04/06/2023] Open
Abstract
BACKGROUND Androgen receptor (AR) splice variants (AR-Vs) have been discussed as a biomarker in prostate cancer (PC). However, some reports question the predictive property of AR-Vs. From a mechanistic perspective, the connection between AR full length (AR-FL) and AR-Vs is not fully understood. Here, we aimed to investigate the dependence of AR-FL and AR-V expression levels on AR gene activity. Additionally, we intended to comprehensively analyze presence of AR-FL and three clinically relevant AR-Vs (AR-V3, AR-V7 and AR-V9) in different stages of disease, especially with respect to clinical utility in PC patients undergoing AR targeted agent (ARTA) treatment. METHODS AR-FL and AR-V levels were analyzed in PC and non-PC cell lines upon artificial increase of AR pre-mRNA using either drug treatment or AR gene activation. Furthermore, expression of AR-FL and AR-Vs was determined in PC specimen at distinct stages of disease (primary (n = 10) and metastatic tissues (n = 20), liquid biopsy samples (n = 422), mCRPC liquid biopsy samples of n = 96 patients starting novel treatment). Finally, baseline AR-FL and AR-V status was correlated with clinical outcome in a defined cohort of n = 65 mCRPC patients undergoing ARTA treatment. RESULTS We revealed rising levels of AR-FL accompanied with appearance and increase of AR-Vs in dependence of elevated AR pre-mRNA levels. We also noticed increase in AR-FL and AR-V levels throughout disease progression. AR-V expression was always associated with high AR-FL levels without any sample being solely AR-V positive. In patients undergoing ARTA treatment, AR-FL did show prognostic, yet not predictive validity. Additionally, we observed a substantial clinical response to ARTA treatment even in AR-V positive patients. Accordingly, multivariate analysis did not demonstrate independent significance of AR-Vs in neither predictive nor prognostic clinical utility. CONCLUSION We demonstrate a correlation between AR-FL and AR-V expression during PC progression; with AR-V expression being a side-effect of elevated AR pre-mRNA levels. Clinically, AR-V positivity relies on high levels of AR-FL, making cells still vulnerable to ARTA treatment, as demonstrated by AR-FL and AR-V positive patients responding to ARTA treatment. Thus, AR-FL and AR-V might be considered as a prognostic, yet not predictive biomarker in mCRPC patients.
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Affiliation(s)
- Neele Wüstmann
- Department of Urology, University Hospital Muenster, Albert-Schweitzer Campus 1 A1, 48149, Muenster, Germany
| | - Konstantin Seitzer
- Department of Urology, University Hospital Muenster, Albert-Schweitzer Campus 1 A1, 48149, Muenster, Germany
| | - Verena Humberg
- Department of Urology, University Hospital Muenster, Albert-Schweitzer Campus 1 A1, 48149, Muenster, Germany
| | - Julia Vieler
- Department of Urology, University Hospital Muenster, Albert-Schweitzer Campus 1 A1, 48149, Muenster, Germany
| | - Norbert Grundmann
- Institute for Bioinformatics, University Hospital Muenster, Muenster, Germany
| | - Julie Steinestel
- Department of Urology, University Hospital Augsburg, Augsburg, Germany
| | - Dorothee Tiedje
- Department of Urology, University Hospital Muenster, Albert-Schweitzer Campus 1 A1, 48149, Muenster, Germany
| | - Stefan Duensing
- Molecular Urooncology, Department of Urology, University of Heidelberg School of Medicine, Heidelberg, Germany
| | - Laura-Maria Krabbe
- Department of Urology, University Hospital Muenster, Albert-Schweitzer Campus 1 A1, 48149, Muenster, Germany
| | - Martin Bögemann
- Department of Urology, University Hospital Muenster, Albert-Schweitzer Campus 1 A1, 48149, Muenster, Germany
| | - Andres Jan Schrader
- Department of Urology, University Hospital Muenster, Albert-Schweitzer Campus 1 A1, 48149, Muenster, Germany
| | - Christof Bernemann
- Department of Urology, University Hospital Muenster, Albert-Schweitzer Campus 1 A1, 48149, Muenster, Germany.
| | - Katrin Schlack
- Department of Urology, University Hospital Muenster, Albert-Schweitzer Campus 1 A1, 48149, Muenster, Germany
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Chung JS, Morgan TM, Hong SK. Clinical implications of genomic evaluations for prostate cancer risk stratification, screening, and treatment: a narrative review. Prostate Int 2020; 8:99-106. [PMID: 33102389 PMCID: PMC7557186 DOI: 10.1016/j.prnil.2020.09.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Accepted: 09/06/2020] [Indexed: 02/08/2023] Open
Abstract
New classification systems based on molecular features have been introduced to improve precision medicine for prostate cancer (PCa). This review covers the increasing risk of PCa and the differences in response to targeted therapy that are related to specific gene variations. We believe that genomic evaluations will be useful for guiding PCa risk stratification, screening, and treatment. We searched the PubMed and MEDLINE databases for articles related to genomic testing for PCa that were published in 2020 or earlier. There is increasing evidence that germline mutations in DNA repair genes, such as BRCA1/2 or ATM, are closely related to the development and aggressiveness of PCa. Targeted prostate-specific antigen screening based on the presence of germline alterations in DNA repair genes is recommend to achieve an early diagnosis of PCa. In cases of localized PCa, even if it has a favorable risk classification, patients under active surveillance with these gene alterations are likely to develop aggressive PCa. Thus, active treatment may be preferable to active surveillance for these patients. In cases of metastatic castration–resistant PCa, BRCA1/2 and DNA mismatch repair genes may be useful biomarkers for predicting the response to androgen receptor–targeting agents, poly (ADP-ribose) polymerase inhibitors, platinum chemotherapy, prostate-specific membrane antigen–targeted therapy, immunotherapy, and radium-223. Genomic evaluations may allow for risk stratification of patients with PCa based on their molecular features, which may help guide precision medicine for treating PCa.
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Affiliation(s)
- Jae-Seung Chung
- Department of Urology, Inje University Haeundae Paik Hospital, Busan, Korea
| | - Todd M Morgan
- Department of Urology, University of Michigan, Rogel Cancer Center, Ann Arbor, MI, USA
| | - Sung Kyu Hong
- Department of Urology, Seoul National University College of Medicine, Seoul, Korea.,Department of Urology, Seoul National University Bundang Hospital, Seongnam-si, Korea
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3
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Bernemann C, Krabbe LM. [AR-V7 as a predictive biomarker for prostate cancer-more than just prophecy]. Urologe A 2019; 59:80-83. [PMID: 31820021 DOI: 10.1007/s00120-019-01086-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Affiliation(s)
- C Bernemann
- Klinik für Urologie und Kinderurologie, Universitätsklinikum Münster, Albert-Schweitzer-Campus 1, 48149, Münster, Deutschland
| | - L-M Krabbe
- Klinik für Urologie und Kinderurologie, Universitätsklinikum Münster, Albert-Schweitzer-Campus 1, 48149, Münster, Deutschland.
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4
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Bernemann C, Krabbe LM, Schrader AJ. Considerations for AR-V7 testing in clinical routine practice. ANNALS OF TRANSLATIONAL MEDICINE 2019; 7:S378. [PMID: 32016096 DOI: 10.21037/atm.2019.12.136] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Christof Bernemann
- Department of Urology, University of Muenster Medical Center, Muenster, Germany
| | - Laura-Maria Krabbe
- Department of Urology, University of Muenster Medical Center, Muenster, Germany
| | - Andres Jan Schrader
- Department of Urology, University of Muenster Medical Center, Muenster, Germany
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5
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Analysis of AR/ARV7 Expression in Isolated Circulating Tumor Cells of Patients with Metastatic Castration-Resistant Prostate Cancer (SAKK 08/14 IMPROVE Trial). Cancers (Basel) 2019; 11:cancers11081099. [PMID: 31374981 PMCID: PMC6721786 DOI: 10.3390/cancers11081099] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Revised: 07/12/2019] [Accepted: 07/30/2019] [Indexed: 12/13/2022] Open
Abstract
Despite several treatment options and an initial high response rate to androgen deprivation therapy, the majority of prostate cancers will eventually become castration-resistant in the metastatic stage (mCRPC). Androgen receptor splice variant 7 (ARV7) is one of the best-characterized androgen receptor (AR) variants whose expression in circulating tumor cells (CTCs) has been associated with enzalutamide resistance. ARV7 expression analysis before and during enzalutamide treatment could identify patients requiring alternative systemic therapies. However, a robust test for the assessment of the ARV7 status in patient samples is still missing. Here, we implemented an RT-qPCR-based assay for detection of AR full length (ARFL)/ARV7 expression in CTCs for clinical use. Additionally, as a proof-of-principle, we validated a cohort of 95 mCRPC patients initiating first line treatment with enzalutamide or enzalutamide/metformin within a clinical trial. A total of 95 mCRPC patients were analyzed at baseline of whom 27.3% (26/95) had ARFL+ARV7+, 23.1% (22/95) had ARFL+ARV7−, 23.1% (22/95) had ARFL−ARV7−, and 1.1% (1/95) had ARFL−ARV7+ CTCs. In 11.6% (11/95), no CTCs could be isolated. A total of 25/95 patients had another CTC analysis at progressive disease, of whom 48% (12/25) were ARV7+. Of those, 50% (6/12) were ARV7− and 50% (6/12) were ARV7+ at baseline. Our results show that mRNA analysis of isolated CTCs in mCRPC is feasible and allows for longitudinal endocrine agent response monitoring and hence could contribute to treatment optimization in mCRPC.
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De Laere B, Oeyen S, Mayrhofer M, Whitington T, van Dam PJ, Van Oyen P, Ghysel C, Ampe J, Ost P, Demey W, Hoekx L, Schrijvers D, Brouwers B, Lybaert W, Everaert EG, De Maeseneer D, Strijbos M, Bols A, Fransis K, Beije N, de Kruijff IE, van Dam V, Brouwer A, Goossens D, Heyrman L, Van den Eynden GG, Rutten A, Del Favero J, Rantalainen M, Rajan P, Sleijfer S, Ullén A, Yachnin J, Grönberg H, Van Laere SJ, Lindberg J, Dirix LY. TP53 Outperforms Other Androgen Receptor Biomarkers to Predict Abiraterone or Enzalutamide Outcome in Metastatic Castration-Resistant Prostate Cancer. Clin Cancer Res 2019; 25:1766-1773. [PMID: 30209161 PMCID: PMC6330086 DOI: 10.1158/1078-0432.ccr-18-1943] [Citation(s) in RCA: 107] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Revised: 08/14/2018] [Accepted: 09/11/2018] [Indexed: 12/11/2022]
Abstract
PURPOSE To infer the prognostic value of simultaneous androgen receptor (AR) and TP53 profiling in liquid biopsies from patients with metastatic castration-resistant prostate cancer (mCRPC) starting a new line of AR signaling inhibitors (ARSi).Experimental Design: Between March 2014 and April 2017, we recruited patients with mCRPC (n = 168) prior to ARSi in a cohort study encompassing 10 European centers. Blood samples were collected for comprehensive profiling of CellSearch-enriched circulating tumor cells (CTC) and circulating tumor DNA (ctDNA). Targeted CTC RNA sequencing (RNA-seq) allowed the detection of eight AR splice variants (ARV). Low-pass whole-genome and targeted gene-body sequencing of AR and TP53 was applied to identify amplifications, loss of heterozygosity, mutations, and structural rearrangements in ctDNA. Clinical or radiologic progression-free survival (PFS) was estimated by Kaplan-Meier analysis, and independent associations were determined using multivariable Cox regression models. RESULTS Overall, no single AR perturbation remained associated with adverse prognosis after multivariable analysis. Instead, tumor burden estimates (CTC counts, ctDNA fraction, and visceral metastases) were significantly associated with PFS. TP53 inactivation harbored independent prognostic value [HR 1.88; 95% confidence interval (CI), 1.18-3.00; P = 0.008], and outperformed ARV expression and detection of genomic AR alterations. Using Cox coefficient analysis of clinical parameters and TP53 status, we identified three prognostic groups with differing PFS estimates (median, 14.7 vs. 7.51 vs. 2.62 months; P < 0.0001), which was validated in an independent mCRPC cohort (n = 202) starting first-line ARSi (median, 14.3 vs. 6.39 vs. 2.23 months; P < 0.0001). CONCLUSIONS In an all-comer cohort, tumor burden estimates and TP53 outperform any AR perturbation to infer prognosis.See related commentary by Rebello et al., p. 1699.
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Affiliation(s)
- Bram De Laere
- Center for Oncological Research (CORE), University of Antwerp, Antwerp, Belgium.
| | - Steffi Oeyen
- Center for Oncological Research (CORE), University of Antwerp, Antwerp, Belgium
| | - Markus Mayrhofer
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
| | - Tom Whitington
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
| | - Pieter-Jan van Dam
- Center for Oncological Research (CORE), University of Antwerp, Antwerp, Belgium
- HistoGeneX NV, Wilrijk, Antwerp, Belgium
| | | | | | - Jozef Ampe
- Department of Urology, AZ Sint-Jan, Brugge, Belgium
| | - Piet Ost
- Department of Radiation Oncology, Ghent University Hospital, Ghent, Belgium
| | - Wim Demey
- Department of Oncology, AZ KLINA, Brasschaat, Belgium
| | - Lucien Hoekx
- Department of Urology, Antwerp University Hospital, Antwerp, Belgium
| | | | | | - Willem Lybaert
- Department of Oncology, AZ Nikolaas, Sint-Niklaas, Belgium
| | - Els G Everaert
- Department of Oncology, AZ Nikolaas, Sint-Niklaas, Belgium
| | | | | | - Alain Bols
- Department of Oncology, AZ Sint-Jan, Brugge, Belgium
| | - Karen Fransis
- Department of Urology, Antwerp University Hospital, Antwerp, Belgium
| | - Nick Beije
- Medical Oncology and Cancer Genomics Netherlands, Erasmus MC Cancer Institute, Erasmus University Medical Center, Rotterdam, the Netherlands
| | - Inge E de Kruijff
- Medical Oncology and Cancer Genomics Netherlands, Erasmus MC Cancer Institute, Erasmus University Medical Center, Rotterdam, the Netherlands
| | - Valerie van Dam
- Center for Oncological Research (CORE), University of Antwerp, Antwerp, Belgium
| | - Anja Brouwer
- Center for Oncological Research (CORE), University of Antwerp, Antwerp, Belgium
| | | | | | | | - Annemie Rutten
- Department of Oncology, GZA Hospitals Sint-Augustinus, Antwerp, Belgium
| | | | - Mattias Rantalainen
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
| | - Prabhakar Rajan
- Centre for Molecular Oncology, Barts Cancer Institute, Queen Mary University of London, London, United Kingdom
| | - Stefan Sleijfer
- Medical Oncology and Cancer Genomics Netherlands, Erasmus MC Cancer Institute, Erasmus University Medical Center, Rotterdam, the Netherlands
| | - Anders Ullén
- Department of Oncology-Pathology, Karolinska Institutet and University Hospital, Stockholm, Sweden
| | - Jeffrey Yachnin
- Department of Oncology-Pathology, Karolinska Institutet and University Hospital, Stockholm, Sweden
| | - Henrik Grönberg
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
| | - Steven J Van Laere
- Center for Oncological Research (CORE), University of Antwerp, Antwerp, Belgium
| | - Johan Lindberg
- Department of Medical Epidemiology and Biostatistics, Science for Life Laboratory, Karolinska Institutet, Stockholm, Sweden
| | - Luc Y Dirix
- Center for Oncological Research (CORE), University of Antwerp, Antwerp, Belgium
- Department of Oncology, GZA Hospitals Sint-Augustinus, Antwerp, Belgium
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7
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Mayrhofer M, De Laere B, Whitington T, Van Oyen P, Ghysel C, Ampe J, Ost P, Demey W, Hoekx L, Schrijvers D, Brouwers B, Lybaert W, Everaert E, De Maeseneer D, Strijbos M, Bols A, Fransis K, Oeyen S, van Dam PJ, Van den Eynden G, Rutten A, Aly M, Nordström T, Van Laere S, Rantalainen M, Rajan P, Egevad L, Ullén A, Yachnin J, Dirix L, Grönberg H, Lindberg J. Cell-free DNA profiling of metastatic prostate cancer reveals microsatellite instability, structural rearrangements and clonal hematopoiesis. Genome Med 2018; 10:85. [PMID: 30458854 PMCID: PMC6247769 DOI: 10.1186/s13073-018-0595-5] [Citation(s) in RCA: 87] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Accepted: 11/05/2018] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND There are multiple existing and emerging therapeutic avenues for metastatic prostate cancer, with a common denominator, which is the need for predictive biomarkers. Circulating tumor DNA (ctDNA) has the potential to cost-efficiently accelerate precision medicine trials to improve clinical efficacy and diminish costs and toxicity. However, comprehensive ctDNA profiling in metastatic prostate cancer to date has been limited. METHODS A combination of targeted and low-pass whole genome sequencing was performed on plasma cell-free DNA and matched white blood cell germline DNA in 364 blood samples from 217 metastatic prostate cancer patients. RESULTS ctDNA was detected in 85.9% of baseline samples, correlated to line of therapy and was mirrored by circulating tumor cell enumeration of synchronous blood samples. Comprehensive profiling of the androgen receptor (AR) revealed a continuous increase in the fraction of patients with intra-AR structural variation, from 15.4% during first-line metastatic castration-resistant prostate cancer therapy to 45.2% in fourth line, indicating a continuous evolution of AR during the course of the disease. Patients displayed frequent alterations in DNA repair deficiency genes (18.0%). Additionally, the microsatellite instability phenotype was identified in 3.81% of eligible samples (≥ 0.1 ctDNA fraction). Sequencing of non-repetitive intronic and exonic regions of PTEN, RB1, and TP53 detected biallelic inactivation in 47.5%, 20.3%, and 44.1% of samples with ≥ 0.2 ctDNA fraction, respectively. Only one patient carried a clonal high-impact variant without a detectable second hit. Intronic high-impact structural variation was twice as common as exonic mutations in PTEN and RB1. Finally, 14.6% of patients presented false positive variants due to clonal hematopoiesis, commonly ignored in commercially available assays. CONCLUSIONS ctDNA profiles appear to mirror the genomic landscape of metastatic prostate cancer tissue and may cost-efficiently provide somatic information in clinical trials designed to identify predictive biomarkers. However, intronic sequencing of the interrogated tumor suppressors challenges the ubiquitous focus on coding regions and is vital, together with profiling of synchronous white blood cells, to minimize erroneous assignments which in turn may confound results and impede true associations in clinical trials.
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Affiliation(s)
- Markus Mayrhofer
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
| | - Bram De Laere
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
- Centre for Oncological Research, University of Antwerp, Antwerp, Belgium
| | - Tom Whitington
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
| | | | | | - Jozef Ampe
- Department of Urology, AZ Sint-Jan, Brugge, Belgium
| | - Piet Ost
- Department of Radiation Oncology, Ghent University Hospital, Ghent, Belgium
| | - Wim Demey
- Department of Oncology, AZ KLINA, Brasschaat, Belgium
| | - Lucien Hoekx
- Department of Urology, Antwerp University Hospital, Antwerp, Belgium
| | | | | | - Willem Lybaert
- Department of Oncology, AZ Nikolaas, Sint-Niklaas, Belgium
| | - Els Everaert
- Department of Oncology, AZ Nikolaas, Sint-Niklaas, Belgium
| | | | | | - Alain Bols
- Department of Oncology, AZ Sint-Jan, Brugge, Belgium
| | - Karen Fransis
- Department of Urology, Antwerp University Hospital, Antwerp, Belgium
| | - Steffi Oeyen
- Centre for Oncological Research, University of Antwerp, Antwerp, Belgium
| | - Pieter-Jan van Dam
- Centre for Oncological Research, University of Antwerp, Antwerp, Belgium
| | | | - Annemie Rutten
- Department of Oncology, GZA Hospitals Sint-Augustinus, Antwerp, Belgium
| | - Markus Aly
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
| | - Tobias Nordström
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
| | - Steven Van Laere
- Centre for Oncological Research, University of Antwerp, Antwerp, Belgium
| | - Mattias Rantalainen
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
| | - Prabhakar Rajan
- Centre for Molecular Oncology, Barts Cancer Institute, Cancer Research UK Barts Centre, Queen Mary University of London, London, UK
| | - Lars Egevad
- Department of Oncology-Pathology, Karolinska Institutet and University Hospital, Stockholm, Sweden
| | - Anders Ullén
- Department of Oncology-Pathology, Karolinska Institutet and University Hospital, Stockholm, Sweden
| | - Jeffrey Yachnin
- Department of Oncology-Pathology, Karolinska Institutet and University Hospital, Stockholm, Sweden
| | - Luc Dirix
- Centre for Oncological Research, University of Antwerp, Antwerp, Belgium
- Department of Oncology, GZA Hospitals Sint-Augustinus, Antwerp, Belgium
| | - Henrik Grönberg
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
| | - Johan Lindberg
- Department of Medical Epidemiology and Biostatistics, Science for Life Laboratory, Karolinska Institutet, Stockholm, Sweden.
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8
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Bernemann C, Steinestel J, Humberg V, Bögemann M, Schrader AJ, Lennerz JK. Performance comparison of two androgen receptor splice variant 7 (AR-V7) detection methods. BJU Int 2018; 122:219-226. [PMID: 29359890 DOI: 10.1111/bju.14146] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
OBJECTIVES To compare the performance of two established androgen receptor splice variant 7 (AR-V7) mRNA detection systems, as paradoxical responses to next-generation androgen-deprivation therapy in AR-V7 mRNA-positive circulating tumour cells (CTC) of patients with castration-resistant prostate cancer (CRPC) could be related to false-positive classification using detection systems with different sensitivities. MATERIALS AND METHODS We compared the performance of two established mRNA-based AR-V7 detection technologies using either SYBR Green or TaqMan chemistries. We assessed in vitro performance using eight genitourinary cancer cell lines and serial dilutions in three AR-V7-positive prostate cancer cell lines, as well as in 32 blood samples from patients with CRPC. RESULTS Both assays performed identically in the cell lines and serial dilutions showed identical diagnostic thresholds. Performance comparison in 32 clinical patient samples showed perfect concordance between the assays. In particular, both assays determined AR-V7 mRNA-positive CTCs in three patients with unexpected responses to next-generation anti-androgen therapy. Thus, technical differences between the assays can be excluded as the underlying reason for the unexpected responses to next-generation anti-androgen therapy in a subset of AR-V7 patients. CONCLUSIONS Irrespective of the method used, patients with AR-V7 mRNA-positive CRPC should not be systematically precluded from an otherwise safe treatment option.
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Affiliation(s)
| | - Julie Steinestel
- Urology, University of Muenster Medical Center, Muenster, Germany
| | - Verena Humberg
- Urology, University of Muenster Medical Center, Muenster, Germany
| | - Martin Bögemann
- Urology, University of Muenster Medical Center, Muenster, Germany
| | | | - Jochen K Lennerz
- Massachusetts General Hospital/Harvard Medical School, Boston, MA, USA
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