Yonsei nomogram to predict lymph node invasion in Asian men with prostate cancer during robotic era

Abstract

OBJECTIVE: To develop a novel nomogram to predict lymph node invasion (LNI) in Asian men undergoing radical prostatectomy (RP) and pelvic LN dissection (PLND) for localised prostate cancer. PATIENTS AND METHODS: The patient cohort included 541 patients who underwent robot-assisted RP and PLND by a single surgeon between January 2008 and December 2011. Patients with dissection of <10 LNs, prostate-specific antigen (PSA) levels of >50 ng/mL, incomplete biopsy data, and treatment with neoadjuvant therapy were excluded. RESULTS: The median (interquartile range) number of LNs removed was 17 (14-22) and 45 patients (8.3%) had LN metastases. On multivariate logistic regression analysis, PSA level, clinical stage and Gleason score were independent predictors of LNI. The bootstrap corrected area under curve of the model incorporating PSA level, clinical stage, and biopsy Gleason score was 0.883. With a cutoff value of 4%, PLND could be omitted in 326 patients (60.2%), missing only two patients (4.4%) with LNI. The sensitivity, specificity, positive predictive value and negative predictive value were 95.6%, 65.3%, 20.0% and 99.4%, respectively. CONCLUSIONS: We report a nomogram to predict LNI in Asian men with prostate cancer. The model demonstrated high accuracy and could be used for counselling patients and the selection of candidates for PLND.