A match-pair analysis of continence in intermediate and high-risk prostate cancer patients after robot-assisted radical prostatectomy: the role of urine loss ratio and predictive analysis.

Background: We aimed to study the continence between intermediate and high-risk cancer patients and the influential factors to recover continence.

Materials and methods: In total, 655 patients underwent surgery by robot-assisted radical prostatectomy between 2010 and 2015. Of 655 patients, 294 were classified according to D'Amico risk groups as intermediate risk or high risk and completed the micturition protocol. Patients with intermediate risk were matched in a 1:1 ratio to patients with high risk for age and body mass index. Urine loss ratio (ULR) was defined as urine loss divided by micturition volumes. Immediate continence was defined with the best cut-off value of ULR.

Results: In total, 117 patients with intermediate risk were matched to those with high risk. The comparison did not show any statistically significant difference in the ULR value ( P  = 0.359) or continence rate ( P  = 0.449). Predictive analysis was performed for the 294 patients (intermediate and high risk), of which 9.5% were classified as incontinent (>1 pad/d). Immediate continence was defined as ULR < 0.049 in 232 (78.9%) patients. Age, preoperative hemoglobin, and duration of catheterization were found influent by univariate analysis. Only age [odds ratio (OR) = 1.072; 95% confidence interval (CI) = 1.020-1.127; P  = 0.006] and duration of catheterization (OR = 1.060; 95% CI = 1.003-1.120; P  = 0.040) were independent influential factors to predict immediate continence.

Conclusion: D'Amico intermediate- and high-risk groups do not differ in continence terms. The ULR value of < 0.049 identifies those patients who recover continence earlier. Age and duration of catheterization were influential factors in predicting immediate continence.