Predictive factors of de novo overactive bladder in clinically localized prostate cancer patients after robot-assisted radical prostatectomy.

OBJECTIVES: To assess the postoperative status of clinically localized prostate cancer patients who underwent robot-assisted radical prostatectomy (RARP) with a focus on de novo overactive bladder (OAB). METHODS: The present study included 156 patients who did not have preoperative OAB and underwent RARP between December 2015 and April 2020 at our institution. Patients were divided into the de novo OAB group and non-OAB group based on the findings of overactive bladder symptoms score (OABSS) 6 months after RARP, and comparative assessments were performed between the two groups. RESULTS: Six months after RARP, de novo OAB was detected in 38 (24.4%) out of 156 patients. Body mass index (BMI) and the proportion of patients with hypertension were significantly higher in the de novo OAB group than in the non-OAB group. No significant differences were observed in the other characteristics examined. Furthermore, the preoperative findings of uroflowmetry and a urodynamic study did not significantly differ between the two groups. Despite the lack of significant differences in preoperative OABSS, total international prostate symptom score, the voiding symptom score, storage symptom score, and quality of life score between the two groups, all of these findings 6 months after RARP were significantly worse in the de novo OAB group than in the non-OAB group. Among the several factors examined, only BMI was independently associated with the development of de novo OAB 6 months after RARP. CONCLUSIONS: Patients with a high BMI may develop de novo OAB after RARP, resulting in the significant deterioration of lower urinary tract symptoms.