Benign prostatic hyperplasia and prostate cancer.

Benign prostatic hyperplasia refers to an anatomic diagnosis, yet in practice it is typically diagnosed clinically on the basis of lower urinary tract symptoms and prostatic enlargement detected on manual rectal examination or transrectal ultrasonography (1). Over the past decade, since benign prostatic hyperplasia (2) and prostate cancer (3) were reviewed in this Journal, there has been a proliferation of research in the basic biology, genetics, and epidemiology of both disorders, and a number of reviews have been published (4-8). During this same time period, considerable change has taken place in the screening and diagnosis of prostate cancer. In the United States and, to a lesser extent, in other countries, the widespread use of prostate-specific antigen (PSA) testing has dramatically influenced the detection, diagnosis, treatment, epidemiology, and natural history of clinically diagnosed prostate cancer and its relation to clinically diagnosed benign prostatic hyperplasia. In the following presentation, the published epidemiologic studies of benign prostatic hyperplasia and prostate cancer will be reviewed, recent findings on the biology of prostate growth will be summarized, how prostate size and urinary symptoms can increase the rate of detection of prostate cancer will be discussed, and, in conclusion, the implications of these findings for the design of future epidemiologic studies of prostate cancer will be presented. For a more comprehensive discussion of the epidemiology and natural history of benign prostatic hyperplasia and urinary symptoms the reader is referred to recent reviews (5-7).