Post-Void Residual Urine Volume is Not a Good Predictor of the Need for Invasive Therapy Among Patients With Benign Prostatic Hyperplasia

Abstract

We assessed the value of baseline PVR as predictor of the need for invasive therapy during long-term followup of patients with clinical BPH treated initially with alpha1-blockers or WW. The records of a cohort of 942 patients with BPH treated with alpha(1)-blockers or WW were reviewed. Baseline I-PSS scores, PSA, prostate volume, uroflowmetry, pressure flow parameters and followup data were collected prospectively. Correlations between PVR and other baseline parameters were calculated. The 5-year cumulative risks of invasive therapy were calculated with the Kaplan-Meier method. After stratification of PVR by various cutoff levels (50, 100 and 300 ml), rate ratios between large and small PVRs were calculated using proportional hazards analyses. PVR has weak (-0.2<R <0.2) correlations with other baseline parameters. With increasing PVR cutoff levels, the 5-year cumulative risk of invasive therapy for the large PVR subgroup, increases from 45% to 64% and from 15% to 21% in the alpha1-blockers and WW group, respectively. Large PVR yields a significant 2-fold up to a 4-fold increased risk of invasive therapy compared to small PVR in both treatment groups. In multivariate models these significant risk differences largely disappear, although a statistically not significant higher risk remains for the large PVR (greater than 300 ml) patients. In general, baseline PVR has little prognostic value for the risk of BPH related invasive therapy in patients on alpha1-blocker and WW. Only patients with large PVR have a 2-fold increased risk of invasive therapy compared to patients with smaller PVR.