Investigating Genomic Aberrations of the Androgen Receptor: Moving Closer to More Precise Prostate Cancer Care?

A New Old Target: Androgen Receptor Signaling and Advanced Prostate Cancer

Owing to the development of multiple novel therapies, there has been major progress in the treatment of advanced prostate cancer over the last two decades; however, the disease remains invariably fatal. Androgens and the androgen receptor (AR) play a critical role in prostate carcinogenesis, and targeting the AR signaling axis with abiraterone, enzalutamide, darolutamide, and apalutamide has improved outcomes for men with this lethal disease. Targeting the AR and elucidating mechanisms of resistance to these agents remains central to drug development efforts. This review provides an overview of the evolution and current approaches for targeting the AR in advanced prostate cancer. It describes the biology of AR signaling, explores AR-targeting resistance mechanisms, and discusses future perspectives and promising novel therapeutic strategies. Expected final online publication date for the Annual Review of Pharmacology and Toxicology, Volume 62 is January 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Abiraterone Rechallenge Based on Sequential Testing of Androgen Receptor Splice Variant 7 Expression in Circulating Tumor Cells: A Case Report

Serial analysis of circulating tumor cells (CTCs) such as androgen receptor splice variant 7 is useful in selecting treatments for castration-resistant prostate cancer (CRPC). We report a case who had been positive for androgen receptor splice variant 7 in CTCs before docetaxel, and was subsequently treated with abiraterone rechallenge because of the negative conversion of androgen receptor splice variant 7 following docetaxel. Although, the rechallenge of anti-androgen agent based on CTCs analysis is expected to be an effective approach, it is yet to be reported. Thus, we chose the candidate for abiraterone rechallenge based on serial CTCs analyses by the AdnaTest. As a result, the patient responded to abiraterone that he once had developed resistance to. Our findings reinforce the utility of AR-V7 as a biomarker in the setting of post-chemo androgen-targeted-therapy rechallenge.