To evaluate the role of intravesical prostatic protrusion (IPP) as a predictive factor for adverse clinical outcomes in patients treated with dutasteride for lower urinary tract symptoms secondary to benign prostatic enlargement (BPE).
In total, 111 patients treated with dutasteride for symptomatic BPE were analyzed. Stepwise multivariate logistic regression was applied to evaluate predictors for acute urinary retention (AUR) or benign prostatic hyperplasia (BPH)-related surgery. We applied an IPP cut-off value of 10 mm. The clinical variables were assessed using univariate analysis.
Of 111 patients, 27 (24.3%) developed AUR or required surgical intervention. On multivariate analysis, IPP remained as the independent predictor for AUR and need for BPH-related surgery (odds ratio, 1.27; P < 0.001). Both international prostate symptom score and maximum urinary flow rate significantly improved in patients with low IPP (P = 0.03 and P < 0.001, respectively), but not in those with high IPP. No significant reduction was found in the degree of IPP despite the significant reduction in prostate volume after dutasteride treatment (P = 0.84 and P < 0.001, respectively). The 3-year cumulative incidence of AUR or BPH-related surgery in the low IPP group versus the high IPP group was 9.9% versus 71.5%, respectively (P < 0.001).
High IPP is associated with a higher risk of treatment resistance, AUR, or the need for prostatic surgery in patients receiving dutasteride treatment for symptomatic BPE. Dutasteride might not be effective for IPP reduction.