Chronic Prostate Inflammation is Associated with Severity and Progression of Benign Prostatic Hyperplasia, Lower Urinary Tract Symptoms and Risk of Acute Urinary Retention

PURPOSE: We evaluated associations between histological prostate inflammation, and the development and progression of benign prostatic hyperplasia/lower urinary tract symptoms in men randomized to placebo in the REDUCE (Reduction by Dutasteride of Prostate Cancer Events) study in a 4-year period. MATERIALS AND METHODS: The association of acute and chronic inflammation detected on baseline biopsies and benign prostatic hyperplasia related parameters, including I-PSS (International Prostate Symptom Score) and prostate volume, at multiple time points during 4 years in men randomized to placebo enrolled in the REDUCE prostate cancer prevention study was analyzed with the Student t-test. The association of inflammation with newly developed benign prostatic hyperplasia/lower urinary tract symptoms and benign prostatic hyperplasia progression in patients with existing benign prostatic hyperplasia/lower urinary tract symptoms was analyzed with univariable and multivariable Cox models. RESULTS: Acute and chronic inflammation was seen in baseline negative biopsies of 641 (15.6%) and 3,216 (78.3%) of the 4,109 men in the study. Chronic but not acute inflammation was associated with slightly higher baseline I-PSS (0.6 difference, p = 0.001) and larger prostate volume (3.2 cc difference, p <0.001), a difference noted throughout the study interval. The presence of acute and chronic inflammation was not associated with the incidence of benign prostatic hyperplasia/lower urinary tract symptoms in men without those conditions at baseline or the progression of symptomatic benign prostatic hyperplasia in men with benign prostatic hyperplasia/lower urinary tract symptoms at baseline. However, an association was observed with more severe inflammation. Chronic inflammation at baseline was associated with an increased risk of acute urinary retention (HR 1.6-1.8, p = 0.001). CONCLUSIONS: Our longitudinal evaluation of REDUCE patients randomized to placebo for 4 years confirmed that chronic inflammation is associated with severity and the progression of benign prostatic hyperplasia and benign prostatic hyperplasia/lower urinary tract symptom outcomes.