Racial differences in cellular composition of benign prostatic hyperplasia

BACKGROUND. The present study was designed to compare the cellular composition of benign prostatic hyperplasia (BPH) in Caucasian-American (CA), African-American (AA), and Japanese (JP) men. METHODS. Biopsy specimens of the prostate were obtained from 15 men of each racial group with a prostate-specific antigen (PSA) of 4.1-10.0 ng/mL. The stained cores were quantitatively analyzed for the percentage of the area with different cellular composition (stroma (S), epithelium (E), epithelial lumen (L), and glandular component (E + L = G)), using computer-assisted color imaging. RESULTS. The mean percent area density of S, E, and L in the prostate of CA men was 84.2, 12.1, and 3.8%, respectively; for AA, 84.4, 12.4, and 3.2%; for JP, 77.4, 15.2, and 7.5%. The S/E ratio is significantly lower in JP than in CA men. The S/G ratio is significantly lower in JP than in CA and AA men. Overall, JP contained more glandular lumen and less stromal component than that of CA and AA. CA and AA showed no significant difference in cellular composition. CONCLUSIONS. The present study demonstrated the differences in cellular composition of BPH among the three races. This cellular composition divergence may account for previously observed racial differences in PSA, PSA density, and the incidence of clinical BPH.