The Risk Factors Of Positive Surgical Margins After Radical Prostatectomy And Analysis Of The Influence Of Location Distribution On Clinical Cure

Objective:To study the risk factors of positive surgical margins(PSMs)especially apical PSMs after radical prostatectomy(RP),and further explore the influence of PSMs at different positions of prostate on postoperative clinical cure.Method:The Clinical data of patients underwent RP in the Second Affiliated Hospital of Nanchang University from June 2017 to December 2022 were retrospectively analyzed,According to the results of pathological reports,the patients were divided into negative surgical margin group and PSMs group,and subdivided into apex positive,basal positive,multiple positive according to the location of PSMs.Patients were divided into apical positive group and apical negative group according to whether the apical surgical margin was positive or not.Clinical cure was defined as serum Prostate specific antigen(PSA)decreased below 0.03ng/ml 6 months after RP,and patients were divided into clinical cure group and clinical cure failure group according to this standard.Non-parametric test and Chi-square test were used to compare the clinic and pathological features between groups,and the meaningful indicators of univariate analysis were incorporated into the multivariate logistic regression model to obtain the independent risk factors of PSMs,apical PSMs and clinical cure failure.Finally,the predictive factors were made into a column graph prediction model.Receiver operating characteristic(ROC)curve and calibration curve were used to test model differentiation and accuracy.Results:A total of 296 patients available for analysis,of which 98(33.1%)were PSMs,43(14.5%)were simple apical PSMs,13(4.4%)were simple basal PSMs,and42(14.2%)were multiple PSMs.The apical PSMs was in 24.0% of patients,Postoperative follow-up showed that 126 cases(42.6%)were cured clinically.Multivariate logistic analysis showed that long prostatic diameter(P=0.002),high Prostate specific antigen density(PSAD)(P<0.001)and p T3 b stage(P=0.001)were independent risk factors for PSMs.Long anteroposterior prostatic diameter(P<0.001),high preoperative serum PSA(P=0.003)and nerve invasion(P=0.037)were independent risk factors for apical PSMs.High preoperative PSAD(P=0.005),smoking(P=0.025),ISUP grade of postoperative pathological ≥4(P<0.001),simple apical PSMs(P<0.001)and multiple PSMs(P=0.039)were independent risk factors for clinical cure failure.The independent predictors of clinical cure failure were made into a column graph prediction model.The area under ROC curve of the prediction model based on the above risk factors was 0.801,the sensitivity was 0.618,and the specificity was 0.873.The calibration curve fit well with the ideal curve.Conclusion 1:Patients with longer anteroposteric diameter,higher PSAD and p T3 b stage have a higher probability of PSMs after RP.Apical PSMs were more likely in patients with longer anteroposteric prostatic diameter,higher preoperative serum PSA,and tumor invasion of nerves.Conclusion 2:High PSAD,smoking,ISUP grade of postoperative pathological ≥4,simple apical PSMs and multiple PSMs were independent risk factors for clinical cure failure.Apical PSMs had the highest effect on clinical cure failure.The visualization column graph model based on the above predictors had a better ability to predict clinical cured.However,further external verification is needed,and early intervention should be carried out for patients with high probability of clinical cure failure predicted by the prediction model.