Abstract
<title>Abstract</title> <p>Background Despite the elevated risk of positive surgical margins (PSM) in certain transition zone (TZ) prostate cancers after laparoscopic radical prostatectomy (LRP), the underlying causes remain unclear. This study seeks to identify key determinants to inform personalized surgical strategies. Methods This retrospective study included 451 patients from three high-volume centers who underwent LRP after preoperative multiparametric magnetic resonance imaging between 2022 and 2023. Results TZ tumors exhibited elevated PSM rates compared to peripheral zone (PZ) tumors in both pT2 and pT3. In the pT3 cohort, clinical under-staging was more frequent among patients with PSM in TZ tumors (69% vs. 28% in PZ, P < 0.01). Despite comparable PSM rates between under-staged and correctly-staged TZ tumors, the under-staged PSM cases exhibited more favorable clinical characteristics. For pT2 TZ tumors, the elevated PSM rate was predominantly apex (36% vs. 21% in PZ, p = 0.03) and strongly associated with nerve-sparing surgery (NS). NS was performed more frequently (59% vs. 19% in PZ) and constituted the majority (86% vs. 29% in PZ) of TZ PSM cases. Furthermore, these PSM apex TZ tumors exhibited more adverse clinical features. Accordingly, a model to predict PSM risk in apex TZ tumors was established. Conclusions For pT3 TZ tumors, clinical under-staging is a critical factor leading to PSM. In pT2 disease, PSM prevention is paramount when operating on apex TZ tumors with adverse features, necessitating more stringent selection criteria for NS in these cases.</p>