Normalized periprostatic fat MRI measurements can predict prostate cancer aggressiveness in men undergoing radical prostatectomy for clinically localised disease

Abstract

Periprostatic and pelvic fat have been shown to influence prostate cancer behaviour through the secretion of chemokines and growth factors, acting in a paracrine mode. We have measured periprostatic fat volume (PFV) with normalisation to prostate gland volume on pelvic magnetic resonance imaging (MRI) and have correlated this with grade (Gleason score; GS) and pathological staging (pT) of prostate cancer (PCa) following radical prostatectomy (RP). PFV was determined using a segmentation technique on contiguous T1-weighted axial MRI slices from the level of the prostate base to the apex. The abdominal fat area (AFA) and subcutaneous fat thickness (SFT) were measured using T1-weighted axial slices at the level of the umbilicus and the upper border of the symphysis pubis, respectively. PFV was normalised to prostate volume (PV) to account for variations in PV (NPFV = PFV/PV). Patients were stratified into three risk groups according to post-operative GS: ≤6, 7(3 + 4), and ≥7(4 + 3). NPFV was significantly different between the groups (p = 0.001) and positively correlated with post-operative GS (ρ = 0.294, p < 0.001). There was a difference in NPFV between those with upgrading of GS from 6 post prostatectomy (2.43 ± 0.98; n = 26) compared to those who continued to be low grade (1.99 ± 0.82; n = 17); however, this did not reach statistical significance (p = 0.11).

Periprostatic fat adipokine expression is correlated with prostate cancer aggressiveness in men undergoing radical prostatectomy for clinically localized disease

“…Recent studies , including our previous study , have confirmed the relationship between the adiposity of periprostatic fat and the aggressivity of PCa. The crosstalk between PPAT and PCa cells could modify the phenotype and characteristics of closely related adipocytes, which can become more metabolically active adipocytes called ‘cancer‐associated adipocytes’ .…”

“…This may suggest that both adiposity and adipokine activities of periprostatic fat have an impact on the aggressivity of PCa; however, at present, imaging is unable to assess adipokine activity of periprostatic fat. Interestingly, BMI, the marker of generalized obesity, has no relationship with NPFV nor with PCa aggressiveness, indicating that periprostatic fat adiposity is more important than BMI .…”

“…The full MRI protocol is detailed elsewhere . Periprostatic fat volume (PFV) was determined using a semi‐automated segmentation technique on contiguous T 1 ‐weighted axial MRI slices from the level of the prostate base to the apex.…”

“…Several studies have found an association between periprostatic fat adiposity and the aggressivity of prostate cancer (PCa) using several different imaging and measurement techniques . In a recent MRI study, we found normalized periprostatic fat volume (NPFV) to be a significant predictor of high grade localized PCa in men opting for radical prostatectomy (RP) ; however, imaging alone cannot discriminate between metabolically more active and less active periprostatic adipose tissue (PPAT).…”

Peri‐prostatic adipose tissue: the metabolic microenvironment of prostate cancer

“…In their study, there were significant associations between PPAT area and both clinical stage and Gleason score, but not for BMI. Recently, two clinical studies have also shown that PPAT measured by MRI is an independent predictor for aggressive PCa .…”