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

Abstract

Objective: 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). Materials and Methods: 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). Results: 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. Conclusion: 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. Level of evidence: Not applicable

The Origin of BPH and Prostate Cancer in Different Prostate Zones and the Impact on the Incidence of Prostate Cancer: A Systematic Review and Update of the Literature for Urologists and Clinicians

“…56 These findings are not challenged in the recent literature, and no systematic reviews or meta-analyses has shown evidence to the contrary. 6,52,55, [57][58][59] This inverse relationship supports the hypothesis that BPH size may be protective against PCa. One potential explanation for this phenomenon could involve dynamic zonal changes in a growing prostate.…”

Computerized metric assessment of glandular tissue volume within the peripheral zone of the prostate using combined magnetic resonance imaging and histopathology: Possible pathophysiological implications on prostate cancer development

“…The selected anatomical slices were measured at the 4:00, 6:00, and 8:00 positions of the posterior prostate for a total of 12 measurements per specimen, thus allowing a representative analysis of the capsular thickness and glandular density of the peripheral zone (GDPZ). This procedure followed a recently published measurement technique of histopathology slides [ 6 ].…”

“…Due to their different embryological origin these zonal structures also vary in biological behavior and clinical significance: The TZ is the primary site of BPH development, whereas the PZ accounts as the origin for by far the majority of all PCa cases (80%–85%) [ 3 4 5 ]. Recent studies suggested that the expanding TZ in growing BPH causes secondary glandular and connective tissue atrophy of the PZ, and thus may inhibit the development of PCa within the PZ [ 5 6 ].…”