PSA values as a surrogate of overall survival (OS) in metastatic castrate resistant prostate cancer (mCRPC) treated with second-line (2L) chemotherapy (CT).

e16104 Background: Numerous reports confirmed that mCRPC patients with ≥ 50% decline in PSA in first-line therapy increase the OS compared with those who did not. This was not demonstrated in second-line treatment setting. In order to evaluate the decrease of PSA as surrogate of OS in men with mCRPC in 2L treatment, we analyzed and compared the decrease in PSA> 30% and its relation to OS. Methods: 72 patients treated at our institution with mCRPC relapsed to Docetaxel were analized, from 2005 to 2013. The primary objective was to determine whether the decrease in PSA ≥ 30% in the first 3 months from first dose CT, correlates with an increase in the OS, and if there are differences between treatment regimens. Results: 25% of patients were treated with Docetaxel, 26% with Mitoxantrone and 49% with Abiraterone. The most common sites of metastasis were bone (85%), liver (3%) and lung (2%). We evaluated OS in all patients and found that in those with PSA decline> 30%, the OS was 10.3 vs 8.0 months in those tha...