Purpose: We examined data from the Medical Therapy of Prostatic Symptoms trial to determine the relationship between baseline TPV and the effect of medical therapy in men with LUTS secondary to BPH.
Materials and methods: A total of 3,047 patients with LUTS were randomized to placebo, 4 to 8 mg doxazosin, 5 mg finasteride or the combination of doxazosin and finasteride. Average treatment duration was 4.5 years The primary outcome was time to overall clinical progression of BPH, defined as a confirmed 4 point or greater increase in AUA SS, acute urinary retention, incontinence, renal insufficiency or recurrent urinary tract infection. Secondary outcomes were the need for invasive therapy for BPH, and changes in AUA SS and the maximum urinary flow rate with time. TPV was measured by transrectal ultrasound at baseline and study end.
Results: In patients with a small prostate (baseline TPV less than 25 ml) combination therapy was no better than doxazosin alone for decreasing the risk of clinical progression of BPH and need for invasive therapy as well as improving AUA SS and the maximum urinary flow rate. However, in patients with moderate size (25 to less than 40 ml) or enlarged (40 ml or greater) glands combination therapy led to a clinical benefit in these outcomes that was superior to that of doxazosin or finasteride.
Conclusions: Combination therapy with doxazosin and finasteride led to a greater decrease in the risk of clinical progression of BPH than either drug alone in patients with LUTS with a baseline TPV of 25 ml or greater.