Androgen receptor variant-driven prostate cancer II: advances in clinical investigation.

CTC AR-V7 detection using the AdnaTest mRNA or Epic nuclear protein assays represents the first analytically and prospective clinically validated liquid biopsy assays that may inform treatment decisions in men with mCRPC, particularly after failure of first-line AR-therapy. The importance of AR-variants is likely to increase with the earlier use of AR-targeting strategies in other settings, and novel interventions for these men are needed.