Internal prostatic architecture on transrectal ultrasonography predicts future prostatic growth: Natural history of prostatic hyperplasia in a 15-year longitudinal community-based study

BACKGROUND From 1992 to 1993, we conducted a cross‐sectional community‐based study to clarify the prevalence of benign prostatic hyperplasia in Japanese men aged 40–79. Based on the results, we hypothesized that the internal prostatic architecture (IPA) on transrectal ultrasonography (TRUS) would predict future prostatic growth. We investigated the changes in prostate volume (PV) over time and validated our hypothesis on predictors for future prostatic growth. METHODS Of 319 participants in the initial study, the PV of 104 men was evaluated by TRUS with approximately a 15‐year follow‐up in the current study. We categorized prostates into three groups based on the IPA: group 1, invisible transition zone (TZ); group 2, visible TZ with an unclear border; and group 3, visible TZ with a clear border. RESULTS Overall PV significantly increased from 17.4 ml to 23.9 ml (P