Real-World Study of Enzalutamide and Abiraterone Acetate (With Prednisone) Tolerability

Inclusion Criteria: * Male 18 years of age or older * Have confirmed metastatic adenocarcinoma of the prostate * Are starting treatment with enzalutamide or abiraterone acetate (with prednisone) for metastatic castration-resistant prostate cancer (mCRPC) at the full recommended dose per each drug's respective prescribing information (PI) * Have an Eastern Cooperative Oncology Group Performance Status score of 0 or 1 * Sign written informed consent Exclusion Criteria: * Have a pre-existing central nervous system (CNS) condition (including, but not limited to, history of stroke or dementia) that, in the participating physician's judgment, would preclude participation in the study * Have known mental illness including, but not limited to, major depressive disorder, general anxiety disorder, or bipolar disorder that, in the participating physician's opinion, could significantly confound the patient-reported outcome (PRO) assessments * Have a history of or ongoing seizure disorder * Have severe hepatic impairment (Child-Pugh Class C) * Have an active infection (example, human immunodeficiency virus \[HIV\], viral hepatitis) or other medical condition that would contraindicate the use of prednisone/prednisolone (systemic glucocorticoid) * Have known alcohol or other substance abuse disorder * Are routinely taking medication-including, but not limited to, over-the-counter medications, supplements, medical marijuana or prescription pain medication-that is known to cause mental confusion or sedation or are using any of the medications * Are routinely taking systemic glucocorticoids (example, prednisone, prednisolone, dexamethasone) at a dosage higher than the equivalent of prednisone 10 milligram (mg) daily * Are currently using or have previously used chemotherapy for any cancer including mCRPC * Are concurrently using any first-generation androgen-receptor blocker (example, bicalutamide, flutamide, nilutamide) for mCRPC * Have previously taken enzalutamide or abiraterone acetate with prednisone * Are not capable of completing tests using a computerized system or completing a participant survey