## 4 Discussion
Additionally, [PERSON] hypothesized that avoiding BNP during LRP would reduce the PSM rate at the prostatic base [10]. A systematic review from 2017 found that the mean base PSM were 4.9% in men who had bladder neck sparing surgery and 1.85% in those who did not [5]. On the other hand, multiple authors maintain that BNP will not compromise oncological control of the disease. [PERSON] concluded in a systematic literature review that BNP was not linked to worse cancer control or a greater incidence of PSM [17]. Patients with or without BNP had comparable PSM results in one meta-analysis from 2016 [18]. Similar findings were observed in a prospectively planned trial involving 1057 males who underwent RARP [19]. The reported rate of PSM after RP exhibits considerable variability in the published literature (6-32%), which can be explained by the different frequency of extracapsular disease in the studies, the difference in surgical experience, and sizeable inter-observer variability in pathologic interpretation of PSM [17]. In our series, PSM were detected in 24.7% of prostatectomy specimens. This rate belongs to the PSM range of 16.6% to 39.4%, which has been reported in some similar studies [20,21]. Overall, the PSM rate in our study was relatively high, which is likely associated with a high frequency of extracapsular disease (52 of 170 patients, 30.6%). The PSM rate in our BNP group was 22.4%, and 27.1% in the non-BNP group. A statistically significant difference between those two groups, in regard to the occurrence of PSM, was not detected (\(p=0.477\)). The rate of PSM at the base of the prostate in the literature varies between 0% and 16.3% [22,23]. In a retrospective study involving 365 patients who underwent RRP with BNP, [PERSON] et al. reported a rate of PSM at the prostate base of 7% [24]. On the other hand, in a prospective study with 555 patients treated similarly, [PERSON] reported a base PSM rate of 2% [25]. In a study from 2009 involving 619 patients treated with RARP, [PERSON] et al. compared the rate of positive margins at the prostate base in the group of patients who underwent BNP and another group treated with the standard surgical technique. In the first group, the base PSM rate was 1.4%, while in the other, it was 2.2%. No statistically significant difference was noted (\(p=0.547\)) [26]. [PERSON] et al. reported similar results, with a base PSM rate of 1.1% in patients with BNP and 2.5% in patients without [25]. In our study, the overall rate of PSM at the prostate base was 7.6%. For patients who underwent BNP, the rate of PSM at the prostate base was 9.4%, compared to 5.9% of those who did not. We demonstrated that performing BNP during RP is not significantly associated with the incidence of PSM at the base of the prostate or any other localization (\(p=0.256\)). A more accurate patient risk assessment and personalized treatment strategies can be achieved by identifying preoperative predictors of PSM following RP. Preoperative PSA and bioptic Gleason score have been identified as preoperative risk factors for PSM after RP in one meta-analysis from 2021 [27]. On the other hand, multiple studies identified PSA and clinical T stage as independent preoperative factors affecting PSM status [7; 23]. In our univariate analysis, we confirmed these results while also recognizing the bioptic Gleason score as a predictor of PSM. However, multivariate analysis indicated that, from all preoperative parameters, only PSA was a statistically significant predictor of PSM (B = 0.057, \(p=0.025\), OR = 1.06, 95% CI 1.01-1.1). Understanding that tumors with higher preoperative PSA, bioptic Gleason score, and clinical T stage, are associated with significantly higher PSM rates can improve patient selection for BNP. PSM after RP can be correlated with a higher risk of BCR [28; 29; 30]. BCR related to PSM may imply local as well as potential distant relapse of the disease. At a median follow-up period of 79 months, [PERSON] et al. found that patients with PSM had a BCR-free survival rate of 79.9%.