Clinical efficacy of combination therapy with an alpha blocker and low-dose sildenafil on post-therapy lower urinary tract symptoms after low-dose-rate brachytherapy for prostate cancer.

Objective: To investigate the efficacy of tamsulosin monotherapy and tamsulosin with low-dose sildenafil combination therapy on lower urinary tract symptoms (LUTS) following low-dose-rate (LDR) brachytherapy in early prostate cancer patients.

Methods: From March 2008 to June 2014, of the 212 prostate cancer patients with a Gleason score ≤7 who received LDR brachytherapy, 80 patients with a prostate volume ≤35 g and progressed LUTS following implantation were selected. All 80 patients took tamsulosin 0.4-mg monotherapy until 1 month after implantation. Then, the patients were divided into two groups; 45 patients received tamsulosin 0.4-mg monotherapy, and 35 patients received tamsulosin 0.4-mg plus sildenafil 25-mg combination therapy due to erectile dysfunction. LUTS were compared between the two groups using the International Prostate Symptom Score (IPSS), the mean maximum flow rate (Q max) and the pre-implantation post-voiding residual (PVR) volume at 1 and 3 months after implantation.

Results: The pre-implantation total IPSS, Q max and PVR for the monotherapy and combination therapy groups were 14.0 ± 6.7, 14.3 ± 3.2 ml/s and 36.3 ± 16.7 ml and 15.3 ± 5.6, 13.7 ± 4.5 ml/s and 39.0 ± 23.4 ml, respectively. At 1 month post-implantation, both groups showed increases in total IPSS and PVR, but no statistically significant differences were observed (P = 0.078, P = 0.23). At 3 months post-implantation, the combination therapy group showed a greater decrease in total IPSS compared with the monotherapy group (P = 0.035), but there were no statistically significant differences in the Q max and PVR between the two groups.

Conclusions: Tamsulosin plus low-dose sildenafil combination therapy is a beneficial treatment for post-implantation progression of LUTS.