TY - JOUR
T1 - Clinical Utility of Circulating Tumour Cell Androgen Receptor Splice Variant-7 Status in Metastatic Castration-resistant Prostate Cancer
AU - Sharp, Adam
AU - Welti, Jon C.
AU - Lambros, Maryou B.K.
AU - Dolling, David
AU - Rodrigues, Daniel Nava
AU - Pope, Lorna
AU - Aversa, Caterina
AU - Figueiredo, Ines
AU - Fraser, Jennifer
AU - Ahmad, Zai
AU - Lu, Changxue
AU - Rescigno, Pasquale
AU - Kolinsky, Michael
AU - Bertan, Claudia
AU - Seed, George
AU - Riisnaes, Ruth
AU - Miranda, Susana
AU - Crespo, Mateus
AU - Pereira, Rita
AU - Ferreira, Ana
AU - Fowler, Gemma
AU - Ebbs, Berni
AU - Flohr, Penny
AU - Neeb, Antje
AU - Bianchini, Diletta
AU - Petremolo, Antonella
AU - Sumanasuriya, Semini
AU - Paschalis, Alec
AU - Mateo, Joaquin
AU - Tunariu, Nina
AU - Yuan, Wei
AU - Carreira, Suzanne
AU - Plymate, Stephen R.
AU - Luo, Jun
AU - de Bono, Johann S.
N1 - Publisher Copyright:
© 2019 The Author(s)
PY - 2019/11
Y1 - 2019/11
N2 - Background: Detection of androgen receptor splice variant-7 (AR-V7) mRNA in circulating tumour cells (CTCs) is associated with worse outcome in metastatic castration-resistant prostate cancer (mCRPC). However, studies rarely report comparisons with CTC counts and biopsy AR-V7 protein expression. Objective: To determine the reproducibility of AdnaTest CTC AR-V7 testing, and associations with clinical characteristics, CellSearch CTC counts, tumour biopsy AR-V7 protein expression and overall survival (OS). Design, setting, and participants: CTC AR-V7 status was determined for 227 peripheral blood samples, from 181 mCRPC patients with CTC counts (202 samples; 136 patients) and matched mCRPC biopsies (65 samples; 58 patients). Outcome measurements and statistical analysis: CTC AR-V7 status was associated with clinical characteristics, CTC counts, and tissue biopsy AR-V7 protein expression. The association of CTC AR-V7 status and other baseline variables with OS was determined. Results and limitations: Of the samples, 35% were CTC+/AR-V7+. CTC+/AR-V7+ samples had higher CellSearch CTC counts (median CTC; interquartile range [IQR]: 60, 19–184 vs 9, 2–64; Mann-Whitney test p < 0.001) and biopsy AR-V7 protein expression (median H-score, IQR: 100, 63–148 vs 15, 0–113; Mann-Whitney test p = 0.004) than CTC+/AR-V7− samples. However, both CTC− (63%) and CTC+/AR-V7− (62%) patients had detectable AR-V7 protein in contemporaneous biopsies. After accounting for baseline characteristics, there was shorter OS in CTC+/AR-V7+ patients than in CTC− patients (hazard ratio [HR] 2.13; 95% confidence interval [CI] 1.23–3.71; p = 0.02); surprisingly, there was no evidence that CTC+/AR-V7+ patients had worse OS than CTC+/AR-V7− patients (HR 1.26; 95% CI 0.73–2.17; p = 0.4). A limitation of this study was the heterogeneity of treatment received. Conclusions: Studies reporting the prognostic relevance of CTC AR-V7 status must account for CTC counts. Discordant CTC AR-V7 results and AR-V7 protein expression in matched, same-patient biopsies are reported. Patient summary: Liquid biopsies that determine circulating tumour cell androgen receptor splice variant-7 status have the potential to impact treatment decisions in metastatic castration-resistant prostate cancer patients. Robust clinical qualification of these assays is required before their routine use.
AB - Background: Detection of androgen receptor splice variant-7 (AR-V7) mRNA in circulating tumour cells (CTCs) is associated with worse outcome in metastatic castration-resistant prostate cancer (mCRPC). However, studies rarely report comparisons with CTC counts and biopsy AR-V7 protein expression. Objective: To determine the reproducibility of AdnaTest CTC AR-V7 testing, and associations with clinical characteristics, CellSearch CTC counts, tumour biopsy AR-V7 protein expression and overall survival (OS). Design, setting, and participants: CTC AR-V7 status was determined for 227 peripheral blood samples, from 181 mCRPC patients with CTC counts (202 samples; 136 patients) and matched mCRPC biopsies (65 samples; 58 patients). Outcome measurements and statistical analysis: CTC AR-V7 status was associated with clinical characteristics, CTC counts, and tissue biopsy AR-V7 protein expression. The association of CTC AR-V7 status and other baseline variables with OS was determined. Results and limitations: Of the samples, 35% were CTC+/AR-V7+. CTC+/AR-V7+ samples had higher CellSearch CTC counts (median CTC; interquartile range [IQR]: 60, 19–184 vs 9, 2–64; Mann-Whitney test p < 0.001) and biopsy AR-V7 protein expression (median H-score, IQR: 100, 63–148 vs 15, 0–113; Mann-Whitney test p = 0.004) than CTC+/AR-V7− samples. However, both CTC− (63%) and CTC+/AR-V7− (62%) patients had detectable AR-V7 protein in contemporaneous biopsies. After accounting for baseline characteristics, there was shorter OS in CTC+/AR-V7+ patients than in CTC− patients (hazard ratio [HR] 2.13; 95% confidence interval [CI] 1.23–3.71; p = 0.02); surprisingly, there was no evidence that CTC+/AR-V7+ patients had worse OS than CTC+/AR-V7− patients (HR 1.26; 95% CI 0.73–2.17; p = 0.4). A limitation of this study was the heterogeneity of treatment received. Conclusions: Studies reporting the prognostic relevance of CTC AR-V7 status must account for CTC counts. Discordant CTC AR-V7 results and AR-V7 protein expression in matched, same-patient biopsies are reported. Patient summary: Liquid biopsies that determine circulating tumour cell androgen receptor splice variant-7 status have the potential to impact treatment decisions in metastatic castration-resistant prostate cancer patients. Robust clinical qualification of these assays is required before their routine use.
KW - Androgen receptor
KW - Androgen receptor splice variant-7
KW - Biomarker
KW - Liquid biopsy
KW - Metastatic castration-resistant prostate cancer
KW - Prognostic
UR - http://www.scopus.com/inward/record.url?scp=85064743531&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85064743531&partnerID=8YFLogxK
U2 - 10.1016/j.eururo.2019.04.006
DO - 10.1016/j.eururo.2019.04.006
M3 - Article
C2 - 31036442
AN - SCOPUS:85064743531
SN - 0302-2838
VL - 76
SP - 676
EP - 685
JO - European Urology
JF - European Urology
IS - 5
ER -