Predictors of biochemical recurrence after robot-assisted radical prostatectomy: single-centre analysis

Abstract

Introduction: We evaluated risk factors for biochemical recurrence (BCR) after robot-assisted radical prostatectomy (RARP) based on our department database.

Material and methods: Patients who underwent RARP between 2018 and 2020 were identified and included in our retrospective study. Patients who received neoadjuvant treatment, patients with positive lymph nodes, salvage prostatectomies, and patients with missing data were excluded. BCR was defined as PSA ≥0.2 ng/ml. Parameters that were investigated were the International Society of Urological Pathologists (ISUP) score, stage, and positive surgical margins (PSM) as they were reported in the pathology report. A subgroup analysis based on the tumour stage was performed.

Results: A total of 414 patients were included in the analysis. Seventy-seven of them experienced BCR. Based on multivariable analysis, ISUP grade was a strong predictor for BCR with odds ratio (OR): 2.86 (CI: 1.49-5.65; p = 0.002), OR: 5.90 (CI: 1.81-18.6; p = 0.003), OR: 4.63 (CI: 1.79-11.9; p = 0.001) for ISUP grade 3, 4, 5, respectively. Regarding tumour stage, pT2 and pT3a did not show any significant difference in predicting BCR (p = 0.11), whereas pT3b stage was a predictor for BCR with OR: 6.2 (CI: 2.25-17.7; p < 0.001). In the subgroup analysis for 206 patients with pT2 disease, ISUP group and PSM were predictors for BCR. On the other hand, when patients with pT3 disease were inspected, the only parameter that was predictive of BCR was pT3b disease (OR: 4.68, CI: 1.71-13.6; p = 0.003). ISUP grade, the extent of T3 disease, and the extent and ISUP grade of surgical margins were not predictors of BCR.

Conclusions: The most important risk factors for BCR after RARP are ISUP grade and tumour stage. In pT2 disease, PSM is a significant predictor of BCR, along with high ISUP grade. The substage pT3b can be considered a predictor of BCR in pT3 cases.

Keywords: PSM; positive margin; prostatectomy; radical prostatectomy; recurrence; surgical margin.