Risk Factors Analysis And Nomogram Construction Of Pelvic Lymph Node-positive In Patients With Prostate Cancer

Objective(s): To study the risk factors of positive pelvic lymph nodes after radical prostatectomy combined with pelvic lymph node dissection in patients with prostate cancer,and construct a nomogram to predict the risk of positive pelvic lymph nodes in patients with prostate cancer,to select potential patients with positive pelvic lymph nodes and guide the selection of surgical methods.Methods: Clinical data of prostate cancer patients who underwent radical prostatectomy combined with pelvic lymph node dissection in our hospital from January 2016 to June 2021 were retrospectively collected.All patients were pathologically diagnosed with prostate cancer after undergoing ultrasound-guided prostate biopsy,and without distant metastasis.Age,clinical T stage,PI-RADS score,prostate volume(g),total prostate-specific antigen(tPSA),free prostate-specific antigen(fPSA),prostate-specific antigen density(PSAD),primary Gleason score(PGleason score),secondary Gleason score,percentage of positive biopsy cores,nerve or vascular invasion,number of pelvic lymph nodes dissected and number of positive pelvic lymph nodes were obtained.SPSS26.0 software was used for statistical analysis of the collected clinical data.Measurement data conforming to normal distribution were expressed as mean standard deviation(),while measurement data conforming to skewed distribution were expressed as median(lower quartile-upper quartile).The statistical data were expressed as percentage(%).Clinical data with statistical significance will be analyzed by binary Logistics regression.R4.2.2 software was used to construct a nomogram of positive risk of pelvic lymph nodes in prostate cancer patients based on the results of binary Logistics regression,and receiver operating characteristic curve(ROC curve)and calibration curve was drawn to verify the efficacy of the prediction model,P<0.05 was considered to be statistically significant between the two groups.Results: A total of 52 patients had complete clinical data,among which 13 patients showed positive pelvic lymph nodes(lymph node-positive group),and the remaining39 patients showed no positive pelvic lymph nodes(lymph node-negative group).Statistical analysis showed that tPSA,fPSA,PSAD,PGleason score,SGleason score,percentage of positive biopsy cores,PI-RADS score,nerve or vascular invasion and clinical T stage were all P<0.05.Binary Logistic regression analysis showed that percentage of positive biopsy cores,SGleason score and PI-RADS score were independent risk factors for positive pelvic lymph nodes of prostate cancer.The ROC curve and calibration curve were constructed based on percentage of positive biopsy cores,SGleason score and PI-RADS score.The area under the curve was 0.928,the Yoden index was 0.846,the sensitivity and specificity were 100.0% and 84.6%respectively,and the average absolute error of the calibration curve was 0.088.Conclusion(s): 1.tPSA,fPSA,PSAD,PGleason score,SGleason score,percentage of positive biopsy cores,PI-RADS score,nerve or vascular invasion,and clinical T stage are correlated with positive pelvic lymph nodes in prostate cancer.The percentage of positive biopsy cores,SGleason score,and PI-RADS score were independent risk factors for positive pelvic lymph nodes in patients with prostate cancer,and the percentage of positive biopsy cores was the strongest predictor of positive pelvic lymph nodes in patients with prostate cancer.2.The nomogram constructed according to the clinical data of patients undergoing single-center radical prostatectomy combined with pelvic lymph node dissection has a good ability to predict the positive risk of pelvic lymph nodes for prostate cancer,which can provide a reference for the selection of surgical methods.