Is one single prostate biopsy helpful for choosing a medical treatment of benign prostatic hyperplasia? A quantitative computerized morphometric study.

OBJECTIVES

Individual differences in proportion of stroma, epithelium, and luminal space components prostatic hyperplasia (BPH) may explain the differences in clinical outcome of the patients treated with alpha-reductase inhibitors or alpha-blocking agents and other alternative treatments. Knowledge of the individual proportions of these elements may orient the clinician toward different therapeutic approaches. To determine whether a single prostate biopsy is representative of the whole adenoma, using quantitative morphometry, we have compared the percentage of smooth muscle cells and glandular cells in one prostate needle biopsy and in the corresponding prostate adenoma removed by open surgery.

METHODS

Quantification was made using a computerized image analysis system and immunohistochemical staining (actin antiactin for the smooth muscle cells and anti-prostate-specific antigen (PSA) for the epithelial cells) in 14 patients who underwent retropubic prostatectomy.

RESULTS

Mean percentage of smooth muscle fibers, glandular epithelium, and glandular lumina in the prostate biopsy were, respectively, 34% (range, 20% to 42%, SD 5.9), 29% (range, 13% to 42%, SD 7.2), and 20% (range, 13% to 30%, SD 4.8). In the corresponding prostate adenoma, they were, respectively, 38% (range, 28% to 45%, SD 4.7), 32% (range, 25% to 40%, SD 4.5), and 19% (range, 13% to 34%, SD 6.1). The mean percentages of epithelial or glandular cells in the prostate biopsy and the corresponding adenoma were not statistically different (P > 0.05), whereas those for the smooth muscle cell percentage were different (P = 0.02). However, a statistically significant correlation between the whole adenoma and the needle biopsy sample was found in the percentage of smooth muscle cells (P = 0.028). Analyzing the morphometric data in conjunction with the serum PSA level and the volume of the adenoma, we found a statistically significant positive correlation between the volume of the adenoma and the ratio (percentage of epithelial cells/serum PSA level) (P = 0.009, r = 0.67).

CONCLUSIONS

Major differences are found in the primary tissue composition of different hyperplastic prostates. Computerized histologic quantification of the different components of BPH in the entire adenoma and a needle biopsy demonstrate that a single prostate biopsy is representative of the entire prostate adenoma. Morphometric data from a single biopsy of the prostate adenoma in combination with the serum PSA level and the volume of the prostate adenoma could therefore help to orient medical treatment of BPH by patient selection based on the knowledge of the distribution of the various components of BPH.