This study evaluated whether physical factors, including myosteatosis and sarcopenia, are prognostic factors in patients with androgen receptor signaling inhibitor-naïve, castration-resistant prostate cancer.<h4>Methods</h4>We retrospectively analyzed 117 androgen receptor signaling inhibitor-naïve patients with castration-resistant prostate cancer who received enzalutamide treatment at The University of Osaka Hospital between 2014 and 2024. This evidence concerns the gene AR and sarcopenia.