This is a pilot study of abiraterone acetate in African American/Black patients with castration-resistant prostate cancer. The primary objective is to determine the correlation between germline polymorphisms and antitumor activity (as defined by a decline in PSA of ≥ 30%) in African American patients with castration-resistant prostate cancer treated with abiraterone acetate. Patients will receive abiraterone acetate until the time of disease progression, in the absence of prohibitive toxicities. Patients will be followed for disease progression and survival.