Effect of Low-dose 500 mg Abiraterone Acetate in Treatment of Metastatic Prostate Cancer Patients

Inclusion Criteria

• •1. Histologically confirmed adenocarcinoma prostate
• •2. Age \>21 years
• •3. Diagnosis of metastatic castration-resistant prostate cancer (mCRPC) (chemotherapy naïve and chemotherapy pre-treated patients) or metastatic hormone-sensitive prostate cancer (mHSPC)
• •4. For mCRPC patients, evidence of castration resistance is defined as disease progression despite a testosterone level \<50ng/dL (or surgical castration)
• •5. Progressive disease was defined as either
• •1. PSA progression according to Prostate Cancer Working Group (PCWG2) criteria15: PSA evidence for progressive prostate cancer consists of a minimum PSA level of at least 2 ng/ml, which has subsequently risen on at least 2 successive occasions, at least 1 week apart
• •2. Radiographic progression according to RECIST 1.1 guidelines or
• •3. 2 or more new lesions on bone scan
• •6. Newly initiated on abiraterone acetate therapy
• •7. Eastern Cooperative Oncology Group (ECOG) performance status grade of 0, 1 or 2.
• •8. Adequate hematologic, hepatic, and renal function would include:
• •* hemoglobin ≥9.0 g/dL independent of transfusions
• •* neutrophils ≥1.5 x 109/L
• •* platelets ≥100 x 109/L
• •* total bilirubin ≤1.5× upper limit of normal (ULN) \[except for subjects with documented Gilbert's disease in which case total bilirubin not to exceed 10× ULN\]
• •* alanine (ALT) and aspartate (AST) aminotransferase ≤2.5X ULN
• •* serum creatinine \<1.5× ULN or calculated creatinine clearance ≥30 mL/min
• •* serum potassium ≥3.5 mmol/L
• •9. Ability to provide informed consent