Benign prostatic hyperplasia (BPH) and prostate cancer (PCa) are two significant urologic diseases affecting ageing men. BPH is histologically evident in over half of men above 50, while PCa is a highly lethal cancer prevalent in men in the United States. Both conditions involve the proliferation of prostatic tissue and often coexist. Recent clinical studies have shown a negative association between BPH size and PCa incidence, although the underlying causes remain unclear. BPH growth occurs exclusively in the transition zone (TZ), while 80–85% of PCa originates in the peripheral zone (PZ). This study aims to use automated imaging techniques to analyse histo-anatomical features in a large sample of prostates of varying sizes. Findings indicate that prostate volume ranges from 20 to 160mL, with a mean of 54.1mL, and capsule thickness ranges from 1.42 to 10.88mm, with a mean of 6.61mm. Epithelial cell density varies from 0.005 to 0.239, with a mean of 0.07. Non-linear relationships between prostate volume and capsule thickness, as well as glandular epithelial cell density, were observed. Prostate volume and capsule thickness are positively associated, while prostate volume and epithelial cell density are negatively associated. Prostate zones have different embryologic origins and are susceptible to distinct pathologies. BPH only occurs in the TZ, while PCa primarily arises in the PZ. Large BPH prostates develop a fibrotic layer inwardly from the anatomical capsule, causing thickening. This fibrotic layer, known as the surgical capsule, facilitates the enucleation of the BPH component during surgery. The study hypothesises that as the TZ expands, it compresses the PZ, leading to glandular atrophy and fibrosis in the PZ, potentially reducing PCa development. Supporting studies include a meta-analysis showing a negative correlation between prostate size and PCa incidence, clinical studies indicating more aggressive PCa in smaller prostates, and mathematical models demonstrating mechanical stress effects on the PZ in large prostates. Additionally, multiparametric MRI studies confirm a compression effect on the PZ in large prostates. The study acknowledges limitations, such as focusing on non-cancerous BPH areas and challenges in reconstructing prostate anatomy from pathology slides. Despite these, the findings support the hypothesis that larger BPH prostates may protect against PCa. This research encourages further investigation into the relationship between BPH size and PCa, which could impact future diagnostic and treatment strategies for both diseases.
Association of prostate size with capsule thickness and glandular epithelial cell density
Reviewed by Asif H Ansari
Association of prostate size with capsule thickness and glandular epithelial cell density: The possible clinical implications on prostate cancer development.
