Evaluation of Response to Abiraterone/Prednisone by Race/Ethnicity and Other Factors in Metastatic Hormone Naive Prostate Cancer

All patients must have a histologically or cytologically proven diagnosis of adenocarcinoma of the prostate. All patients must have metastatic disease as evidenced by soft tissue and/or bony metastases prior to initiation of androgen deprivation therapy (ADT). NOTE: ADT does not include treatment with anti-androgens such as bicalutamide or flutamide or five alpha reductase inhibitors such as finasteride or dutasteride.

Patients must have radiographic assessments of all disease including bone scan (or PET scan) within 42 days prior to registration. All disease will be assessed and documented on the appropriate CRF.

Patients must have had no more than 42 days of prior castration (medical or surgical) for metastatic prostate cancer prior to starting abiraterone. The start date of medical castration is considered the day the patient first received an injection of a LHRH agonist/antagonist (or orchiectomy), not an oral antiandrogen. • If the method of castration was luteinizing hormone releasing hormone (LHRH) agonist or antagonist (i.e., leuprolide, goserelin or degarelix), the patient must be willing to continue the use of LHRH agonist/antagonist and add Abiraterone + Prednisone treatment. • If the patient was on an antiandrogen (e.g. bicalutamide, flutamide), the patient must be willing to switch over to Abiraterone + Prednisone treatment. There is no limit on how many days a patient may have been on an antiandrogen (e.g. bicalutamide, flutamide) or a five alpha reductase inhibitor (e.g. finasteride or dutasteride) prior to going on study and no washout is required.

Patients may have received prior ADT - neoadjuvant and/or adjuvant setting only - but it must not have lasted for more than 36 months. Single or combination therapy allowed. At least 6 months must have elapsed since completion of ADT in the neoadjuvant and/or adjuvant setting, and serum testosterone must be > 50 ng/dL (non-castrate levels) within 28 days prior to registration. NOTE: Serum testosterone assessment is required for eligibility for only those patients with prior treatment with neoadjuvant or adjuvant ADT.