LAUSR

318 Background: Metastases (M+) detection is a critical event in non-metastatic castration-resistant prostate cancer (nmCRPC), as it entails a change in PC management and is a potential surrogate for survival at this stage. PSA doubling time (PSA-DT) has been described as a prognostic factor to develop M+. However, there could be other relevant factors to raise suspicion of progression in nmCRPC patients. The “IDENTIFICA” study tries to describe disease characteristics and clinical drivers that make physicians suspect the presence of M+ in nmCRPC patients in clinical practice in Spain. Methods: Observational, transversal, multicenter study. nmCRPC patients with physician’s suspiction of M+ were selected. Imaging tests to rule out metastases were requested; clinical drivers were described, along with clinical data related to prostate cancer (PC). Results: 197 nmCRPC patients were recruited (Jan-Jun 2018). Median age was 81.3 years. Median time from the onset of androgen deprivation therapy (ADT) to CRPC was 5.1 years (IQR: 2.5-8.2). ADT was the first PC treatment for 64.4% of , while 41.2% went through a curative-intent treatment. Median PSA-DT at CRPC diagnosis was 7.5 months. Time from PC diagnosis to CRPC was influenced by Gleason score at diagnosis ( p=0.001), primary curative intent treatment ( p<0.001), and PSA-DT at CRPC diagnosis ( p=0.04). Most important clinical drivers leading physicians to request imaging were PSA value, PSA-DT and PC guidelines recommendations. M+ were detected in 23 patients (16.5%). In the multivariate analysis, there was a statistically significant relation between positive imaging and time on ADT (OR 1.16; 95% CI 1.018-1.325; p=0.026) and time on CRPC status (OR 1.55; 95% CI 1.038-2.302; p=0.032). In this interim analysis, PSA and PSA-DT seemed not to be statistically related to M+ appearance. Conclusions: PSA and PSA-DT seem to be the most influential drivers to request imaging tests during follow-up of nmCRPC patients. Time on ADT and time on CRPC status could be relevant factors for M+ detection and phycisians should be aware of them and not just PSA or PSADT to properly ask for imaging tests.