Association of prostate size with capsule thickness and glandular epithelial cell density: The possible clinical implications on prostate cancer development

Abstract

Benign prostatic hyperplasia (BPH) and prostate cancer (PCa) are the two most common urologic diseases in aging males. The negative association between prostate/BPH size and incidence of PCa is well documented in the literature. However, the exact mechanism is not well understood. This study aims to further investigate the possible effect of prostate volume on prostate capsule thickness and glandular cell density in the prostatic peripheral zone (PZ). A total of 100 patients were selected that had undergone radical prostatectomy with prostate sizes ranging from 20 to 160 mL. Quantitative measurements of capsule thickness and density of epithelial glands within the peripheral zone not affected by cancer were analysed and calculated on histo-anatomical slides using computer-based imaging software. Associations between the different variables were calculated using Spearman correlation with 95% confidence intervals (CIs). In the non-cancerous areas of the PZ, prostate volume and average capsule thickness are positively associated ( rs = +0.6526, 95% CI +0.5233 to +0.7526, p < 0.0001), while prostate volume and average glandular epithelial cell density of the PZ are negatively associated ( rs = −0.6011, 95% CI −0.7133 to −0.4589, p < 0.0001). These associations remain consistent on subgroup analysis. The findings of this study support the hypothesis that transition zone (TZ) growth in large BPH prostates may cause pressure on the outer PZ, leading to fibrosis and atrophy of the glandular tissue. This may provide a protective effect against PCa, as most PCa originates in the PZ of the prostate. Not applicable