Available published studies evaluating the association between nerve-sparing robot-assisted radical prostatectomy (RARP) and risk of ipsilateral positive surgical margins were subject to selection bias. The aim of this study is to overcome these limitations by using multivariable regression analysis.
Patients undergoing RARP for prostate cancer at four institutions from 2013 to 2018 were included. A multilevel logistic random intercept model, including covariates on patient level and side-specific factors on prostate lobe level, was used to evaluate the association between nerve-sparing and risk of ipsilateral positive margins.
A total of 5,148 prostate lobes derived from 2,574 patients that underwent RARP were analyzed. Multivariable analysis showed nerve-sparing to be an independent predictor for ipsilateral positive margins (OR: 1.42, 95% CI: 1.14-1.82). Other significant predictors for positive margins were respectively PSAD (OR: 3.64, 95% CI 2.36-5.90) and side specific covariates including highest preoperative ISUP biopsy grade (ORs of 1.58 [95% CI 1.13-2.53], 1.62 [95% CI 1.13-2.69], 2.11 [95% CI 1.39- 3.59] and 4.43 [95% CI 3.17-10.12] for respectively ISUP grade 2, 3, 4 and 5), presence of extraprostatic extension on MRI (OR: 1.42, 95% CI 1.03-1.91) and percentage of positive cores on systematic biopsy (OR 3.82, 95% CI 2.50-5.86).
Nerve-sparing was associated with an increased risk of ipsilateral positive surgical margins. The increased risk of positive margins should be taken into account when counselling patients that opt for nerve-sparing RARP.
The Journal of urology. 2020 Jan 23 [Epub ahead of print]
T F W Soeterik, H H E van Melick, L M Dijksman, S Stomps, J A Witjes, J P A van Basten
Department of Value-Based Healthcare, Santeon, Utrecht, The Netherlands., Department of Urology, St. Antonius Hospital, Nieuwegein-Utrecht, The Netherlands., Department of Value-Based Healthcare, St. Antonius Hospital, Nieuwegein-Utrecht, The Netherlands., Department of Urology, Hospital Group Twente, Almelo-Hengelo, The Netherlands., Department of Urology, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands., Department of Urology, Canisius Wilhelmina Hospital, Nijmegen, The Netherlands.