Circulating tumor cell-based or tissue biopsy-based AR-V7 detection: which provides the greatest clinical utility?

Metastatic castration-resistant prostate cancer (mCRPC) is a condition characterized by cancer progression in the setting of low serum testosterone levels (1,2), and represents the lethal phase of the disease. Biologically, the development of castration-resistance occurs through a multitude of primarily androgen receptor (AR)-dependent mechanisms such as AR amplification, AR mutation, AR splice variant expression, and increase in synthesis of intratumoral and adrenal androgens through CYP17 and other pathways (3,4).