A Nomogram for Predicting Pelvic Lymph Node Metastasis in Prostate Cancer

Abstract

<i>Background</i>: Prostate cancer (PCa) is prone to lymph node metastasis. In this report, the authors described a model predictive of the probability of lymph node metastasis in prostate cancer patients. <i>Methods</i>: Two-hundred seventy-eight middle-high-risk PCa patients who received laparoscopic radical prostatectomy (LRP) combined with extended pelvic lymph node dissection (e-PLND) in our hospital were selected as the subjects and the authors performed a retrospective analysis. According to the postoperative pathological results, the patients were divided into a pelvic lymph node metastasis group (n=100) and a non-pelvic lymph node metastasis group (n=178). Univariable and multivariable logistic regression analyses were performed to identify independent risk factors for pelvic lymph node metastasis from PCa. Finally, a clinical prediction model nomogram was further established and verified, and a calibration plot was drawn to verify the accuracy of the model. <i>Results</i>: The TPSA level, FPSA level, PI-RADS score, biopsy ISUP classification and Gleason score of the two groups were statistically different (P<0.05), and there was no statistical difference between the age groups (P>0.05). Receiver operating characteristic curve (ROC) showed that the best diagnostic cut-off value of TPSA was 77.45 ng/ml (AUC=0.785, 95%CI: 0.729-0.842), and the best diagnostic cut-off value of FPSA was 0.085 ng/ml (AUC=0.282, 95%CI: 0.215-0.348). Univariable and multivariable logistic regression analyses showed that, TPSA level (OR=1.00, 95%Cl: 1.000-1.006, P<0.05), FPSA level (OR=0.00, 95%Cl: 0.000-0.089, P<0.01), PI-RADS score (OR=9.26, 95%CI: 5.278-16.248, P<0.01) and biopsy ISUP grade (OR=1.69, 95%CI: 1.163-2.450, P<0.01) were independent predictors of pelvic lymph node metastasis. <i>Conclusions</i>: The nomogram established in this study has a good predictive ability for pelvic lymph node metastasis in patients with PCa, and can provide a reference for the selection of clinical treatment options.