Long-Term Outcomes And Predictive Factors In Patients (Pts) With Metastatic Castration-Resistant Prostate Cancer (Mcrpc) Showing Abiraterone Withdrawal Syndrome (Aws) After Docetaxel (Doc) Treatment.

324 Background: AWS has been rarely described as a possible PSA reduction, with or without radiological responses, observed after abiraterone acetate (AA) suspension due to disease progression. According to this possibility, all pts progressing under AA were usually monitored for at least 4 wks to evaluate if they developed AWS; if PSA decreased, the subsequent treatment was delayed until the occurrence of biochemical and/or radiological progression. The present study is aimed to assess long-term outcomes and predictive factors in DOC pre-treated mCRPC pts experiencing AWS. Methods: We evaluated a consecutive series of 73 pre-treated mCRPC pts, who received AA in our Hospital after DOC failure: all pts were treated with AA 1,000 mg po + prednisone 10 mg po daily; the treatment continued until progression disease (PD) which required to be confirmed by imaging. For each pt we have recorded the pre and post-AA clinical history, the treatment details and outcomes. All pts stopped AA due to progressive disease...