Positive surgical margins after robot-assisted radical prostatectomy Long-term oncologic consequences.

INTRODUCTION

We aimed to evaluate the prognostic significance of positive surgical margins (PSM) and associated clinicopathologic factors on long-term oncologic outcomes following robot-assisted radical prostatectomy (RARP).

METHODS

We analyzed a prospectively maintained registry of patients undergoing RARP between 2003 and 2022, stratified by surgical margin status (positive vs. negative [NSM]). Primary outcomes were overall survival (OS) and biochemical recurrence-free survival (BCRFS). Multivariable Cox regression adjusted for age, prostate-specific antigen (PSA), Gleason grade group (GGG), pathologic stage, nodal status, and adjuvant therapy. A prognostic nomogram for OS was developed in the PSM cohort.

RESULTS

Among 3969 patients, 459 (11.4%) had PSM, which was more common in the presence of adverse pathologic features. On unadjusted analysis, PSM was associated with worse OS (hazard ratio [HR] 1.39, 95% confidence interval [CI] 1.02-1.90, p=0.036) and BCRFS (HR 2.20, 95% CI 1.62-2.97, p<0.001). After adjustment, PSM was not independently associated with OS (adjusted [a]HR 1.16, p=0.377) or BCRFS (aHR 0.86, p=0.343). In the PSM cohort, ≥pT3a disease, node-positive status, and advanced pathologic stage were strong predictors of mortality (HRs 3.91, 3.86, and 3.62, respectively), while adjuvant radiation therapy was associated with improved survival (HR 0.46, p=0.025). The PSM-specific nomogram demonstrated time-dependent area under the curve (AUC) of 0.737 (3 years), 0.713 (5 years), 0.774 (10 years), and 0.932 (20 years).

CONCLUSIONS

PSMs are associated with worse unadjusted outcomes, largely driven by their association with high-risk pathologic features, but are not independently prognostic after accounting for tumor biology and disease stage. A PSM-specific nomogram may support individualized postoperative risk stratification and shared decision-making, pending external validation.