Relationship between changes in prostate-specific antigen and the percent of prostatic epithelium in men with benign prostatic hyperplasia

Objectives: Pretreatment knowledge of prostate gland histology would allow a more scientifically based selection of medical therapy for men with benign prostatic hyperplasia (BPH) and may increase the effectiveness of the pharmacologic agents available. Changes in prostate-specific antigen (PSA), or PSA velocity, may reflect prostatic epithelial growth in BPH. Our objective was to determine if PSA velocity prior to diagnosis correlated with the relative amount of epithelium in BPH tissue. Methods: We evaluated 39 men with BPH who had serial PSA determinations (mean, 5.4) on frozen sera from 2.3 to 25.1 years before diagnosis, and archival material from simple prostatectomy available for pathologic evaluation. We used an immunoenzymatic staining technique for PSA to bind prostatic epithelium selectively so that color differences in the stained tissue sections could be used to quantify stroma, epithelium, and glandular lumina. Results: The average percentage of epithelium (%E) was 1 2.4 and the average stroma-epithelial ratio (SER) was 6.6. The correlation of PSA velocity for the three visits nearest to prostatectomy (n = 32) versus %E and SER was significant (P = 0.003 for both). The PSA value nearest to prostatectomy (n = 39) was directly correlated with %E and SER (P = 0.0001 and P = 0.001, respectively). Conclusions: These data suggest that PSA and PSA velocity are directly related to the histologic makeup of the prostate in men with BPH. Thus, pretreatment evaluation of PSA could be useful as part of an evaluation to direct BPH therapy.