Intra-operative frozen section analysis to increase the rate of nerve-sparing procedures without compromising cancer control: Results from a contemporary population of patients treated with robotic assisted radical prostatectomy

INTRODUCTION & OBJECTIVES: Effectiveness and clinical benefit of intra-operative frozen-section (IFS) analysis during radicalprostatectomy are still unclear. In this study we hypothesized that IFS is associated with an increased probability of nerve sparing (NS)procedures as well as improved functional outcomes, without compromising cancer control.MATERIAL & METHODS: We identified 1,830 consecutive prostate cancer patients treated with robot-assisted radical prostatectomy(RARP) between 2006 and 2014 at 2 tertiary care centres. Patients were divided in two groups according to IFS status [performed (IFS+)vs. not performed (IFS-)]. Additionally, patients were stratified according to D’Amico risk group classification. The main outcomes were: (i)receiving bilateral NS-RARP; (ii) biochemical recurrence (BCR), defined as postoperative PSA value ≥0.2 ng/mL and rising; (iii) urinarycontinence (UC) recovery, defined as being pad-free over a 24-hour period; (iv) erectile function (EF) recovery, defined as post-operativeInternational Index of Erectile Function (IIEF)-EF ≥22. EF recovery was evaluated only in patients with a preoperative IIEF-EF ≥22 withavailable data regarding postoperative IIEF-EF (n=624). Multivariable logistic regression analysis tested the association between IFS (IFS+vs. IFS-) and the probability of receiving bilateral NS-RARP. Covariates consisted of patient age, PSA density, and D’Amico risk groupcategory. Kaplan-Meier method was used to assess the differences between BCR, UC and EF recovery rates according to IFS (IFS+ vs.IFS-).RESULTS: Overall, IFS was performed in 918 (50%) patients. The rate of bilateral NS-RARP was significantly higher in IFS+ compared toIFS- patients (87% vs.72%; p<0.001). After stratification according to the D’Amico risk group, the rate of bilateral NS-RARP between IFS+vs IFS- individuals was 90% vs 88% for low risk, 89% vs 69% for intermediate risk, and 62% vs 32% for high risk patients, respectively (allp<0.001). At logistic regression analysis, IFS represented the most important predictor of bilateral NS procedure (OR: 6.2; 95% CI: 3.0-12.8; p<0.001). No significant difference in terms of BCR and UC recovery between the IFS+ and IFS- patients was observed, even afterrisk group stratification (all p>0.07). Conversely, the EF recovery rate at 2 years was 70% vs 61% in IFS+ compared to IFS- (p=0.04). Thestatistical significance of this finding was more pronounced when focusing only on intermediate-risk patients (67% vs 43%; p=0.001).CONCLUSIONS: Patients submitted to IFS had a 6-fold higher probability of receiving bilateral NS technique and had a significantly higherrate of EF recovery over time. Compared to standard technique, IFS analysis improves EF recovery without compromising cancer control,especially in intermediate-risk patients