Assessing the Impact of Positive Surgical Margins on Mortality in Patients Who Underwent Robotic Radical Prostatectomy: 20 Years' Report from the EAU Robotic Urology Section Scientific Working Group

Abstract

Background: Positive surgical margins (PSMs) are frequent in patients undergoing radical prostatectomy (RP). The impact of PSMs on cancer-specific (CSM) and overall (OM) mortality has not yet been proved definitively.

Objective: To evaluate whether the presence and the features of PSMs were associated with CSM and OM in patients who underwent robotic-assisted RP.

Design, setting, and participants: A cohort of 8141 patients underwent robotic-assisted RP with >10 yr of follow-up.

Outcome measurements and statistical analysis: Cox multivariable analyses assessed the impact of margin status (positive vs negative) and PSM features (negative vs <3 mm vs >3 mm vs multifocal) on the risk of CSM, OM, and biochemical recurrence (BCR) after adjusting for potential confounders. We repeated our analyses after stratifying patients according to clinical (Cancer of the Prostate Risk Assessment [CAPRA] categories) and pathological characteristics (adverse: pT 3-4 and/or grade group [GG] 4-5 and/or pN1 and/or prostate-specific antigen [PSA] persistence).

Results and limitations: PSMs were found in 1348 patients (16%). Among these, 48 (3.6%) patients had multifocal PSMs. Overall, 1550 men experienced BCR and 898 men died, including 130 for prostate cancer. At Cox multivariable analyses, PSMs were associated with CSM in patients with adverse clinical (Intermediate risk: hazard ratio [HR]: 1.71, p = 0.048; high risk: HR: 2.20, p = 0.009) and pathological (HR: 1.79, p = 0.005) characteristics. Only multifocal PSMs were associated with CSM and OM in the whole population (HR for CSM: 4.68, p < 0.001; HR for OM: 1.82, p = 0.037) and in patients with adverse clinical (intermediate risk: HR for CSM: 7.26, p = 0.006; high risk: HR for CSM: 9.26, p < 0.001; HR for OM: 2.97, p = 0.006) and pathological (HR for CSM: 9.50, p < 0.001; HR for OM: 2.59, p = 0.001) characteristics. Potential limitations include a selection bias and a lack of information on the Gleason score at PSM location.

Conclusions: We did not find an association between unifocal PSMs and mortality. Conversely, our results underscore the importance of avoiding multifocal PSMs in patients with adverse clinical (intermediate- and high-risk CAPRA score) and pathological (GG ≥4, pT ≥3, pN1, or PSA persistence) characteristics, to enhance overall survival and reduce CSM.

Patient summary: In this study, we evaluated whether the presence and the characteristics of positive surgical margins were associated with mortality in patients who underwent robotic-assisted radical prostatectomy. We found that the presence of positive surgical margins, particularly multifocal margins, was associated with mortality only in patients with adverse clinical and pathological characteristics.

Keywords: Cancer-specific mortality; Long-term oncological outcomes; Positive surgical margins; Prostate cancer; Robotic surgery; Robotic-assisted radical prostatectomy.