Integrating Magnetic Resonance Chemical Shift Imaging for Localized Prostate Cancer Risk Stratification on the Basis of the Impact of Periprostatic Brown Adipocytes Within Tumor Microenvironment.

Background: We sought to characterize periprostatic adipose tissue (PPAT) with magnetic resonance imaging (MRI) featuring water-to-oil ratio (R) to detect brown adipocyte (BAT).

Patients And Methods: Between November 2021 and September 2023, 21 localized patients with prostate cancer were studied, categorized as low (n = 4), intermediate (n = 4), and high risk (n = 13). We utilized MRI to analyze the water-only signal and fat-only signal. R was used to predict the risk stratification. Tissue samples, including periprostate fat, were collected during surgery, processed, and stained with hemotoxylin and eosin (H&E) for microscopic analysis. Periprostate adipose cell supernatants were used to treat cancer cells (PC3 and LNCaP) in vitro.

Results: We found significantly higher periprostatic adipose tissue R in the high and intermediate risk groups compared with the low risk group (52.12 versus 30.48; p < 0.0001). The receiver operating characteristic curve for distinguishing advanced tumors using PPAT R in MRI imaging yielded an area under the curve of 0.64, which increased to 0.90 after incorporating initial PSA. Immunofluorescence, H&E staining, and immunohistochemistry revealed the presence of brown adipocytes, marked by uncoupling protein 1 expression, in periprostate tumor fat. Results indicate that BAT-related adipokines promote epithelial-mesenchymal transition and invasiveness in human prostate cancer cells.

Conclusions: In the study, the chemical shift image of MRI in 21 localized patients with prostate cancer revealed higher periprostatic adipose tissue water-to-oil ratio among patients with high-risk prostate cancer. Adipokines within the tumor-microenvironment attribute to the cancer aggressiveness, and targeting the fat fraction signal in MRI could improve the current risk stratification strategy.