Any Correlation Between Prostate Volume and Incidence of Prostate Cancer: A Review of Reported Data for the Last Thirty Years

Abstract

Purpose: Prostate cancer (PCa) is the most common non-skin cancer in men worldwide and more than 80% of men with PCa also have histo-anatomical findings of benign prostate hyperplasia (BPH). It is well documented that BPH develops in the transition zone (TZ), whereas 80-85% of PCa originates in the peripheral zone (PZ) of the prostate. Possible causal links between both disease entities are controversially discussed in the current literature. Some studies have reported that larger prostates have a decreased incidence of PCa compared to smaller prostates. The purpose of this systematic review is to comprehensively summarize studies analyzing any association between prostate gland volume and incidence of PCa.

Methods: A thorough literature review was performed between 01.01.1990 through 02.28.2020 using PubMed and applying the "PRISMA" guidelines. Inclusion and exclusion criteria were defined.

Results: Our systematic review found 41 articles reporting an inverse (negative) relationship between prostate gland volume and incidence of prostate cancer. Sample sizes ranged from 114 to 6692 patients in these single institutional and multi-institutional studies. Thirty-nine (95%) of the 41 articles showed a statistically significant inverse relationship. In our search, no study was found showing a positive correlation between BPH size and the incidence of PCa.

Conclusion: To our knowledge, this is the first systematic review on the important clinical question of interaction between prostate size and the incidence of PCa. The results are demonstrating an inverse relationship, and therefore reveal strong evidence that large prostates may be protective of PCa when compared to smaller prostates.

Keywords: benign prostate hyperplasia; inverse relationship; prostate size.

Figure 1

PRISMA flowchart for literature search and selection of studies.

Figure 2

Forest plot for p-value of reviewed studies.

Figure 3

H&E-stained slides of different sized prostate specimens at 50× magnification: (A) Small Prostate Specimen (24 g). The external, posterior margin is inked and marked with an asterisk*. A decent number of hyperplastic glands (as indicated by arrows) are present and easily visible in the peripheral zone (PZ) close to the thin capsule (black line). Reproduced with permission from Dove Medical Press Limited, Guzman JA, Sharma P, Smith LA et al. Histological changes of the peripheral zone in small and large prostates and possible clinical implications. Res Rep Urol. 2019;11:77–81. (B) Large Prostate Specimen (100 g). The external, posterior margin is also inked and marked with an asterisk*. The arrow is indicating an atrophic gland within the extended fibrotic layer/ surgical capsule (black line). This capsule is much thicker in comparison to Figure 2A, and no hyperplastic glands are present. Reproduced with permission from Dove Medical Press Limited, Guzman JA, Sharma P, Smith LA et al. Histological changes of the peripheral zone in small and large prostates and possible clinical implications. Res Rep Urol. 2019;11:77–81.