Predictive factors for the effectiveness of novel androgen receptor axis‐targeted agents in patients with metastatic prostate cancer

Objective Novel androgen receptor axis‐targeted agents (ARATAs) have been developed for mCRPC and improved overall survival (OS). Here, we aimed to find predictors who will receive the greatest benefits from ARATAs. Methods We previously performed a multicenter study to identify prognostic factors for metastatic hormone‐sensitive prostate cancer (mHSPC, n = 148) and mCRPC (n = 99), and showed that the bone scan index (BSI) was one of the significant prognostic factors for 3‐year OS (PROSTAT‐BSI study). mHSPC progressed to mCRPC (n = 101), for which 69 patients were treated with (n = 39) or without ARATAs (n = 30, prior to the approval of ARATAs). The 69 patients were divided into two groups according to patient factors, and these cohorts were further divided into two subgroups by usage of ARATAs. OS was compared between subgroups in each group. Results The predictors were age (