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 (  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.