Benign prostate hyperplasia as a potential protective factor against prostate cancer: Insights from a magnetic resonance imaging study of compositional characteristics

Abstract

Purpose The structural relationship between benign prostate hyperplasia (BPH) and prostate cancer (Pca) is controversial. The purpose of our study was to examine the association between quantitative prostate compositional metrics by magnetic resonance imaging (MRI) and Pca. Methods We identified 405 patients who underwent prostate MRI and biopsy and/or prostatectomy from January 2019 to January 2021 at our institution. Segmentation volumetric methods were used to assess central gland (CG) and peripheral zone (PZ) volume. PZ mean thickness and mean apparent diffusion coefficient (ADC), marker of underlying histologic components, were measured. Multivariable logistic regression was performed with outcomes of ≥Grade Group (GG) 2 Pca and for multifocal disease. Results On multivariable analysis, higher CG volumes were at lower odds of ≥GG2 disease (n = 227) (OR: 0.97, 95% CI 0.96–0.98, p < 0.0001), taking into account PZ volume (p = 0.18) and thickness (p = 0.70). For every one cc increase in CG volume, there was an approximately 3% decrease in odds of ≥GG2 disease. Similar findings were noted for multifocal disease (n = 180) (OR: 0.97, 95% CI 0.96–0.98, p < 0.0001). Notably, ADC of the normal PZ was not significantly associated with CG volume (p = 0.21) nor a predictor of disease (p = 0.49). Conclusions Increasing central gland volume, driven by BPH, is associated with lower odds of significant Pca, including multifocal disease, while PZ anatomic and histologic surrogate changes were noncontributory. Findings support BPH impediment of global tumor growth predicted by theoretical mechanobiological model. This potential stabilizing factor should be further studied for risk stratification and in consideration for BPH therapy.

Impact of the bladder detrusor muscular ring on lower urinary tract symptoms due to benign prostatic hyperplasia: A quantitative MRI analysis

“…Radiologist with 15 years prostate MRI experience, blinded to IPSS scores and clinical information, measured the following parameters using Dynacad software(InVivo) (Figure 1 and Figures –): (a) manual segmentation central gland (CG) volume 14,15 ; (b) manually segmented peripheral zone volume; (c) IPP volume via manual segmentation of central gland volume interior to the outer bladder circumference on sagittal T2W images from lateral to lateral in entirety; (d) central gland mean ADC by manual segmentation of the entire central gland via 3D region‐of‐interest (ROI) software on axial ADC images. PI‐RADS 3 or above lesions were not contoured into the 3D ADC; (e) LH volume via segmentation on axial T2W images with borders as previously defined 16 ; (f) intrapelvic volume via segmentation on wide field of view axial T2W whole pelvis from superior acetabulum to pubic symphysis with lateral obturator muscle boundaries, posterior with iliococcygeus muscle and anterior with rectus wall; (g) DMR surrounding the bladder outlet area internal to the low signal intensity wall via multiplanar reformations based on orthogonal planes manually adjusted perpendicular to the course of the bladder wall at the neck; (h) DMR surrounding the bladder outlet diameter as a straightforward and more routinely available alternative to area, measured from the anterior to the posterior bladder neck detrusor muscular low signal intensity wall on the mid sagittal T2W urethral plane; (i) prostate urethra angle on mid sagittal T2W urethral plane 17 ; (j) peripheral zone background score with ordinal score of 1–4 as described in recent literature 11 …”