Chromogranin A predicts outcome in prostate cancer patients treated with abiraterone.

In this retrospective study, we evaluated the chromogranin A (CgA) baseline value as a predictor of clinical outcome in patients with metastatic castration-resistant prostate cancer (CRPC) treated with abiraterone 1000 mg per day, whose disease progressed after docetaxel chemotherapy. In the 48 evaluable patients, serum CgA level was normal when <120  ng/ml (group A, n=16), within three times the upper normal value (UNV) when between 120 and 360 (group B, n=16), more than three times the UNV when ≥360  ng/ml (group C, n=16). Decline in PSA level ≥50% or more (PSA RR) was observed in 26 of 48 (54%) patients.