silodosin-mediated improvements in the signs and symptoms of BPh: does prostate size matter?

correspondence: steven A Kaplan institute for Bladder and Prostate health, Weill cornell Medical college, cornell University, F9 West, Box 261, 525 east 68th street, new York, nY 10065, UsA Tel +1 212 746 4811 Fax +1 212 746 5329 email [email protected] Objective: The uroselective α-blocker silodosin significantly improved International Prostate Symptom Score (IPSS) in two 12-week, double-blind (DB), placebo-controlled Phase III studies in men aged $ 50 years with symptoms of benign prostatic hyperplasia (BPH) and maintained symptom improvement during a 9-month open-label (OL) extension. This post-hoc analysis evaluated the effects of estimated prostate volume (EPV) on silodosin-mediated symptom improvement. Methods: Patients were stratified by EPV (,30 mL or $ 30 mL) calculated from prostatespecific antigen (PSA) concentrations using a published algorithm. Group comparisons were done by analysis of covariance with last observations carried forward. Results: Of 890 patients with PSA baseline data, 192 had EPV , 30 mL and 698 had EPV $ 30 mL. During DB treatment, silodosin was associated with significant symptom improvement (adjusted mean difference versus placebo) in men with EPV , 30 mL (−2.0; P = 0.038) and those with EPV $ 30 mL (−3.0; P , 0.0001). Among patients who received silodosin during DB treatment, changes from baseline in IPSS to the end of OL extension (mean ± standard deviation) were similar for EPV , 30 mL (n = 60, −7.0 ± 6.8) and EPV $ 30 mL (n = 242, −8.0 ± 7.1; P = 0.416). Also, among patients who received placebo as DB treatment, symptom improvement at the end of OL extension was similar for EPV , 30 mL (n = 62, −6.2 ± 8.1) and EPV $ 30 mL (n = 275, −6.7 ± 6.1; P = 0.339). Conclusion: Silodosin effectively relieved BPH-related symptoms for up to 12 months, irrespective of prostate size, including in patients with enlarged prostates.