Development and comparison of a Chinese nomogram adding multi-parametric MRI information for predicting extracapsular extension of prostate cancer

// Yuke Chen 1,2,* , Wei Yu 1,2,* , Yu Fan 1,2 , Liqun Zhou 1,2 , Yang Yang 1 , Huihui Wang 3 , Yuan Jiang 3 , Xiaoying Wang 3 , Shiliang Wu 1,2 and Jie Jin 1,2 1 Department of Urology, Peking University First Hospital, Xicheng, Beijing, China 2 Institute of Urology, Peking University, National Urological Cancer Center, Beijing, China 3 Department of Radiology, Peking University First Hospital, Xicheng, Beijing, China * These authors have contributed equally to this work Correspondence to: Shiliang Wu, email: // Jie Jin, email: // Keywords : prostate cancer, radical prostatectomy, extracapsular extension, nomogram, multi-parametric magnetic resonance imaging Received : March 28, 2016 Accepted : July 10, 2016 Published : August 23, 2016 Abstract Purpose: To improve the performation of a nomogram for predicting side-specific extracapsular extension (SS-ECE). Results: One hundred and ninety-six patients (55.5%) had ECE on final pathology. Bilateral and unilateral ECE rate was 13.9% (49/353) and 41.6% (147/353), respectively. The mean age was 65.9 years and the mean serum prostate specific antigen (PSA) was 15.0 ng/ml. Based on multivariate logistic regression analysis, clinical stage (cStage), PSA, Gleason sum, percentage of positive cores, and ECE risk score were significant predictors of ECE. The current nomogram had higher predictive accuracy (0.851) and superior calibration. According to the decision curve analysis (DCA) results, the updated nomogram demonstrated a high net benefit across a wide range of threshold probabilities. Materials and Methods: We studied 353 patients with cStage T1c-T3 prostate cancer underwent radical prostatectomy. The candidate predictors associated with ECE were cStage, PSA, Gleason sum, percentage of positive cores, maximum cancer percentage and ECE risk score from multi-parametric magnetic resonance imaging (MP-MRI). The receiver operating characteristic (ROC) analysis was performed and an updated nomogram was constructed. The DCA was performed to test the predictive ability of the nomogram. In addition, the validation and calibration of the Memorial Sloan-Kettering cancer center (MSKCC) nomograms were performed in the current subjects. Conclusions: Predictors, including cStage, PSA, Gleason sum, percentage of positive cores, maximum cancer percentage, and ECE risk score, were combined to construct a SS-ECE prediction nomogram. And the current nomogram might help urologists in decision-making process of preserving or resecting neurovascular bundles preoperatively.