Meaningful Radiographic and Metabolic Response to Enzalutamide Plus Radium-223 Therapy in Metastatic Castration-Resistant Prostate Cancer With PSA-Discordant Progression: A Case Report.

Abstract

IntroductionThe combination of enzalutamide and radium-223 has demonstrated clinical efficacy in metastatic castration-resistant prostate cancer; however, real-world evidence remains limited, particularly with PSA-discordant progression.Case presentationA 74-year-old man with high-risk localized prostate cancer was treated with androgen deprivation therapy followed by definitive external beam radiotherapy. Eight months later, the disease progressed radiographically with extensive bone, nodal, and solitary liver metastases, while prostate-specific antigen levels remained persistently low, consistent with prostate-specific antigen-discordant progression. Bone turnover markers and disease activity markers were markedly elevated. Combination therapy with enzalutamide and radium-223 was initiated, and six cycles of radium-223 were completed. Following treatment, skeletal disease activity and bone turnover markers improved markedly. Apart from grade 3 anemia requiring transfusion, no severe adverse events occurred.ConclusionThis case suggests that enzalutamide combined with radium-223 may provide clinical benefit in metastatic castration-resistant prostate cancer with PSA-discordant progression.