A Correlative Study of Biomarkers of Resistance in Patients With Castrate Resistant Prostate Cancer Treated With Abiraterone

Inclusion Criteria: * Signed written informed consent. Before any study procedures are performed, subjects (or their legally acceptable representatives) will have the details of the study described to them, and they will be given a written informed consent document to read. If subjects consent to participate in the study, they will indicate that consent by signing and dating the informed consent document in the presence of study personnel * Be suitable for receiving treatment with abiraterone acetate and prednisone * Patients must have histologically or cytologically confirmed adenocarcinoma of the prostate without neuroendocrine differentiation or small cell histology * Patients may not receive any other investigational agent or dose escalation of abiraterone acetate during study participation * Patient consents to comply to treatment with abiraterone acetate as directed by their physician Exclusion Criteria: * Taking a dose of abiraterone acetate other than 1g daily or lack of compliance to daily dosing of abiraterone acetate and prednisone * Patients receiving spironolactone or any other steroidogenic compounds in excess of the associated prednisone 5mg bid are excluded due to the potential for androgen receptor agonism