Should obesity be associated with worse urinary continence outcomes after robotic-assisted radical prostatectomy? a propensity score matching analysis

To analyze the association between obesity and urinary incontinence rate in men submitted to robot-assisted radical prostatectomy (RARP) in a high-volume cancer center. We reported 1.077 men who underwent RARP as the primary treatment for localized prostate cancer from 2013 to 2017. Patients were classified as non-obese (normal BMI or overweight) or obese men (BMI ≥30kg/m2). They were grouped according to the age, PSA level, D'Amico risk group, Gleason score, ASA classification, pathological stage, prostate volume, salvage/adjuvant radiotherapy, perioperative complications, and follow-up time. Urinary continence was defined as the use of no pads. For the analysis of long-term urinary continence recovery, we conducted a 1:1 propensity-score matching to control confounders. Among the obese patients, mean BMI was 32.8kg/m2, ranging 30 - 45.7kg/m2. Only 2% was morbidly obese. Obese presented more comorbidities and larger prostates. Median follow-up time was 15 months for the obese. Complications classified as Clavien ≥3 were reported in 5.6% of the obese and in 4.4% of the non-obese men (p=0.423). Median time for continence recovery was 4 months in both groups. In this analysis, HR was 0.989 for urinary continence recovery in obese (95%CI=0.789 - 1.240; p=0.927). Obese can safely undergo RARP with similar continence outcomes comparing to the non-obese men when performed by surgeons with a standardized operative technique. Future studies should perform a subgroup analysis regarding the association of obesity with other comorbidities, intending to optimize patient counseling.