Benign prostatic hyperplasia (BPH) and benign prostatic hypertrophy are often incorrectly used interchangeably. BPH is a histological diagnosis defined as an increase in the total number of prostatic stromal cells and prostatic glandular epithelial cells within the transition zone. As a result of this hyperplasia, large, discrete, prostatic nodules can develop. Benign prostatic hypertrophy, on the other hand, is defined as an increase in the size of the individual prostatic cells resulting in a global enlargement of the prostate gland with no discrete nodularity. Through a combination of these two processes, benign prostatic enlargement (BPE) results. If BPE leads to obstruction of the bladder neck in the absence of prostate cancer, benign prostatic obstruction (BPO) results.
Lower urinary tract symptoms (LUTS) have been defined by an international consensus conference as a constellation of symptoms related to storage and/or voiding disturbances in aging men. LUTS can be subdivided into symptoms of urinary storage (e.g., urgency, frequency, and nocturia), urinary voiding (e.g., straining to void, urinary intermittency, dysuria, and hesitancy), and postvoiding symptoms (e.g., sensation of incomplete bladder emptying and postvoid urinary dribbling).
Descriptive terms for changes in prostate architecture are often misused.
BPO identifies the effect of prostatic tissue on urination.
LUTS is a catch-all term for voiding symptoms.
EPIDEMIOLOGY OF BENIGN PROSTATIC HYPERPLASIA AND LOWER URINARY TRACT SYMPTOMS
BPH increases in prevalence as individuals age. Nearly 70% of U.S. men between 60 and 69 years and nearly 80% of men age ≥70 years have some degree of BPH.1 An autopsy study found the prevalence of histologically confirmed BPH in prostates with gross enlargement of 14%, 37%, and 39%, respectively, in men 50 to 59, 60 to 69, and older than 70 years.2 The prevalence and severity of LUTS in men increase with advancing age; the prevalence is low in men less than 40 years of age, but approaches 80% in men over 80 years. The risk of surgery related to BPH also increases with age and is considerably greater for a man age 80 years than a man aged 40 years.3
PATHOPHYSIOLOGY OF BPH AND LUTS
The pathophysiology of BPH remains incompletely understood, but it is likely a multifactorial process that results in part from new epithelial gland formation and/or a loss of programmed cell death.4 Androgens are implicated in the proliferation of prostatic cells, as well as in the inhibition of cell death. Prepubertal testosterone deficiency prevents the development of BPH later in life; individuals who undergo surgical orchiectomy prior to puberty do not develop BPH.
LUTS also is a multifactorial process; the prostate plays an important but likely overemphasized role in its etiology. The severity of the voiding symptoms is poorly correlated with prostate size.5 The prostatic contribution to LUTS includes a static component consisting of the enlargement of the ...