Many terms are used to describe benign prostate disease, and often interchangeably. Precision is important, however, because the conditions overlap only partially (Figure 50-1). Benign prostatic hyperplasia (BPH) is a histological condition characterized by benign proliferation of stromal and/or epithelial prostate tissue. Benign prostate enlargement (BPE) occurs in about half of men with BPH, and is quantified by milliliters of prostate tissue. Bladder outlet obstruction (BOO) occurs in only a subset of men with BPE. Older men often have voiding symptoms (urgency, frequency, nocturia, slow stream, hesitancy, incomplete emptying, postvoiding dribbling, and incontinence), which maybe related to BPH, BPE, BOO, age-related physiologic changes in the lower urinary tract, or comorbid conditions and medications. Therefore, voiding symptoms are best described by the nonspecific term lower urinary tract symptoms (LUTS).
Examples of incomplete concordance between benign prostatic hyperplasia, benign prostatic enlargement, and bladder outlet obstruction.
Early autopsy and epidemiological studies demonstrated a marked rise in prevalence of BPH and BPE with age, especially during the sixth and seventh decades, and a similar relationship between age and “clinical BPH” (LUTS and BPE on examination) (Figure 50-2). Overall, 28% to 35% of older men without previous prostate surgery have moderate to severe LUTS. More recent data from longitudinal epidemiological studies and placebo arms of treatment trials confirm that the incidence of benign prostate disease gradually and variably increases with age until the ninth decade (Figure 50-3). Only weak correlations exist between BPE, BOO, and LUTS, suggesting that their relationships are nonlinear and complex.
Autopsy evidence of prostate hyperplasia (percent of prostates, solid line with ▪), mean weight (mL) of all prostates (dashed line with ♦), mean weight of prostates with hyperplasia (dashed line with ▴), and percent of men with lower urinary tract symptoms (solid line with ○). Data from Berry SJ, Coffey DS, Walsh PC, Ewing LL. The development of human benign prostatic hyperplasia with age. J Urol. 132:474–479, 1984; Guess HA, Arrighi HM, Metter EJ, Fozard JK. Cumulative prevalence of prostatism matches the autopsy prevalence of benign prostatic hyperplasia. Prostate. 17:214–216, 1990.
Incidence per 1000 man-years of BPH, as defined by LUTS plus a clinical diagnosis of BPH, medical therapy for BPH, or surgical treatment for BPH during follow-up. Data from: Verhamme KMC, Dieleman JP, Bleumink GS, et al. Triumph Pan European Expert Panel. Incidence and prevalence of lower urinary tract symptoms suggestive of benign prostatic hyperplasia in primary care—the Triumph project. Eur Urol. 42:323–328, 2002.
Some data suggest that African-American men have a higher risk of benign prostate disease urinary retention, and BPE/BOO surgery, possibly because they have higher levels of 5α-reductase and larger prostate transitional zone volume (see ...