IntroductionMetachronous metastatic prostate cancer (mmPCa) patients harbor different characteristics and outcomes, relative to DeNovo metastatic PCa patients. Onset of metastatic disease might be influenced by primary PCa characteristics such as Gleason score (GS) or cancer stage, as well as overall survival (OS) by timing of metastatic onset. Patients and MethodsWe relied on an institutional tertiary-care database to identify mmPCa patients. Kaplan Meier and Cox Regression models tested for onset of metastases and OS, stratified according to GS, pathological stage and time to mmPCa. ResultsOf 341 mmPCa patients, 8% harbored GS6 vs. 41% vs. 51% GS7 and GS8-10. Median time to onset of metastatic disease was 79 vs. 54 vs. 41 months for GS6 vs. GS7 vs. GS8-10 (p=0.01). Moreover, median time to onset of metastases was 64 vs. 44 months for pT1-2 vs. pT3-4 mmPCa patients undergoing radical prostatectomy (p=0.027). In multivariable Cox regression models, higher GS and pT-stage was associated with earlier onset of metastases. Additionally, significant OS differences could be observed for time interval of <24 vs. 24-60 vs. 60-120 vs. ≥120months between primary PCa diagnosis and onset of mmPCa. Specifically, median OS was 56 vs. 69 vs. 97 months vs. not reached (p<0.01) for these categories. In multivariable Cox regression, shorter time to metastatic onset was associated with shorter OS. ConclusionTiming of mmPCa is strongly influenced by grading and pT-stage in real-life setting. OS benefits can be observed with longer time interval between primary PCa diagnosis and onset of mmPCa. Micro Abstract: Onset of metastatic disease for prostate. Cancer (PCa) might be influenced by primary PCa characteristics such as Gleason score (GS) or cancer stage, as well as overall survival (OS) by timing of metastatic onset. We relied on an institutional tertiary-care database and found that timing of smPCa is strongly influenced by GS and pT-stage in real-life setting. OS benefits can be observed with longer time interval between primary PCa diagnosis and onset of smPCa.