Possible clinical implications of prostate capsule thickness and glandular epithelial cell density in benign prostate hyperplasia.

PURPOSE: The negative correlation between BPH-size and incidence of prostate cancer (PCa) is well-documented in the literature, however the exact mechanism is not well-understood. The present study uses histo-anatomical imaging to study prostate volume in correlation to prostate capsule thickness, and glandular epithelial cell density within the peripheral zone (PZ). MATERIALS AND METHODS: Specimens were selected from radical prostatectomies ranging from 20 to 160 mL based on ease of anatomical reconstruction by the slides. A total of 60 patients were selected and underwent quantitative measurements of prostate capsule thickness and glandular epithelial density within the PZ using computer-based imaging software. Pearson's correlation and a stepwise multiple linear regression analysis was conducted to determine the relationship between these measured parameters and the clinical characteristic of these patients. RESULTS: Pearson's correlation analysis revealed a strongly significant, negative correlation between prostate volume and glandular epithelial cell density (r(58)=-0.554, p<0.001), and a strongly significant, positive correlation between prostate volume and average capsule thickness (r(58)=0.462, p<0.001). Results of multiple regression analysis showed that average glandular epithelial cell density added statistically to this prediction (p<0.05). CONCLUSIONS: The results suggest that growth of the transition zone in BPH causes increased fibrosis of the PZ, leading to atrophy and fibrosis of glandular cells. As 80% of PCa originates from the glandular epithelium within the PZ, this observed phenomenon may explain the inverse correlation between BPH and PCa that is well-documented in the literature.

Quantitative measurements of prostate capsule and gland density and their correlation to prostate size: possible clinical implications in prostate cancer.

PURPOSE: To study histo-anatomical imaging features and possible association between prostate volume, capsule thickness and glandular density within the peripheral zone (PZ) of prostates of different sizes. METHODS: Patients were selected who had undergone radical prostatectomy. Specimen selection was based on two factors: first, easy reconstruction of prostate anatomy by the histological slides; and second, based on prostate size. Specimens were chosen with small (< 35 cc) and also with large size (> 80 cc). A total of 20 patients were selected. None of these patients had undergone previous treatment. Computer-based imaging for quantitative measurements of capsule thickness and glandular density within the PZ were performed. Multiple regression analysis was performed to determine the relationship between these measured parameters and the clinical characteristics of these patients. RESULTS: Multiple regression analysis revealed a strong, positive association between prostate size and average capsule thickness; on the contrary, we found a negative correlation between prostate volume and average glandular density. Fibrotic thickness of the capsule was associated with gland atrophy and decreased gland density within the PZ. CONCLUSIONS: The results suggest that BPH may be associated with the development of fibrosis and gland atrophy within the peripheral zone. As 80% of prostate cancer originates from the glandular epithelium within the peripheral zone, this observed phenomenon may explain the inverse relationship between BPH and incidence of prostate cancer well documented in the literature.