Abiraterone and Prednisone without Hormone Therapy in Treating Patients with Metastatic Prostate Cancer

Inclusion Criteria

• The patient must be able to provide study-specific informed consent prior to study entry
• Eastern Cooperative Oncology Group (ECOG) performance status 0-2
• Pathologically proven diagnosis of prostate adenocarcinoma
• Patients must have metastatic disease
• Patients may have metastatic castration-resistant prostate cancer (mCRPC) or may have metastatic castration-sensitive disease
• Patients must be maintained on a GnRH analogue (agonist [leuprolide, goserelin, triptorelin, histerelin, deslorin] or antagonist [degarelix])
• The patient and the investigator have decided that the next line of cancer therapy will be abiraterone plus prednisone and the initial dose of abiraterone will be 1000 mg daily. Or patients may already be on abiraterone with prednisone at a dose of 1000 mg daily along with a GnRH analogue
• Total testosterone level of < 50 ng/dl
• Total bilirubin < 2.0 x upper limit of normal (ULN)
• Aspartate aminotransferase (AST) =< 3 x ULN
• Alanine aminotransferase (ALT) =< 3 x ULN
• Absolute neutrophil count > 1.5 K/mm^3
• Platelets > 100 K/mm^3
• Hemoglobin >= 9.0 g/dL
• Calculated creatinine clearance >=30 mL/min

Exclusion Criteria

• History of bilateral orchiectomy
• History of hypopituitarism
• For patient not yet started on abiraterone with prednisone, uncontrolled hypertension (systolic blood pressure > 170 mm Hg or diastolic blood pressure > 100 mm Hg)
• Patients must not have New York Heart Association class III or IV heart failure at the time of screening. Patients must not have any unstable angina, myocardial infarction, or serious uncontrolled cardiac arrhythmia within 6 months prior to registration
• Any other serious illness or medical condition that the principal investigator feels would make the patient a poor candidate for this study