Active surveillance in prostate cancer patients: Modeling upgrading and upsizing at 1 year rebiopsy.

90 Background: Prostate biopsy findings at diagnosis and follow-up are essential criteria in Active Surveillance (AS). In a previous work (Nicolai Eur Urol Suppl 2013) upgrading (UPG) and upsizing (UPS) at 1-yr rebiopsy resulted to be independent outcomes with different predictors. Aim of the present work is to validate these models on an independent population and to evaluate the probability of not-developing UPG, thus the chance of continuing...