A Novel Tool for Predicting Extracapsular Extension During Graded Partial Nerve Sparing in Radical Prostatectomy

OBJECTIVES: To create a statistical tool for the estimation of extra-capsular extension (ECE) level of prostate cancer and determine the nerve sparing (NS) approach that can be safely performed during radical prostatectomy (RP).
PATIENTS AND METHODS: A total of 11,794 lobes, from 6,360 patients who underwent robot-assisted RP between 2008 and 2016 were evaluated. Clinicopathological features were included in a statistical algorithm for the prediction of the maximum ECE width. Five multivariable logistic models were estimated for: presence of ECE and ECE width greater than 1, 2, 3, and 4mm. A five-zone decision rule based on a lower and upper threshold is proposed. Using a graphical interface, surgeons can view a patient's pre-treatment characteristics and a curve showing the estimated probabilities for ECE amount and the areas identified by the decision rule.
RESULTS: Out of 6,360 patients, 1,803 (28.4%) were affected by non-organ-confined disease. ECE was present in 1,351 lobes (11.4%) and extended beyond the capsule for more than 1, 2, 3, and 4mm in 498 (4.2%), 261 (2.2%), 148 (1.3%), 99 (0.8%) cases, respectively. ECE width was up to 15 mm (IR 1.00 - 2.00). The 5 logistic models showed good predictive performance; the area under the ROC curve was: 0.81 for ECE, and 0.84, 0.85, 0.88, and 0.90 for ECE width greater than 1, 2, 3, and 4mm, respectively.
CONCLUSION: This novel tool predict with a good accuracy the presence and amount of ECE. Furthermore, the graphical interface available at www.prece.it can supports surgeons in patient counselling and preoperative planning. This article is protected by copyright. All rights reserved.