High GLUT1 membrane expression and low PSMA membrane expression in Ductal Adenocarcinoma and Intraductal Carcinoma of the prostate.

Background: Both Ductal Adenocarcinoma (DAC) and Intraductal Carcinoma (IDC) of the prostate are generally associated with aggressive clinical behavior and poor prognosis, which were linked with discordant FDG positivity and low Prostate-Specific Membrane Antigen (PSMA) expression. A recent study only cited a DAC patient with low Ga-PSMA-11 PET/CT uptake but high F-FDG PET/CT uptake, however, there is lack of directly compared articles nor large data sets. Hence, the objective of this study was to investigate the expression of PSMA and GLUT1 in DAC and IDC-P patients.

Methods: The study was conducted on 87 DAC or/and IDC-P patients without any treatment and 97 PAC patients with a Gleason score ≥8 of prostate biopsies and prostatectomy samples between August 2017 and August 2022. We performed immunohistochemical staining and scoring of various cancer component samples from the patients to reflect the protein expression levels of PSMA and GLUT1.

Results: PSMA expression in PAC was significantly higher than in DAC/IDC-P (141.2 vs 78.6, p < 0.001). There was no significant difference in PSMA expression between DAC/IDC-P and adjacent PAC (78.6 vs 93.4, p = 0.166). GLUT1 expression was higher in DAC/IDC-P than in adjacent PAC (68.6 vs 51.3, p = 0.007), but was still lower than that in pure PAC (68.6 vs 93.1, p = 0.0014). It is worth noting that GLUT1 membrane expression in DAC/IDC-P was significantly increased than in pure PAC (13.0 vs 6.6, p = 0.025), and in PAC adjacent to DAC/IDC-P (13.0 vs 2.0, p < 0.001).

Conclusions: In DAC/IDC-P tissues, PSMA expression is low, while GLUT1 expression, especially GLUT1 membrane expression is high. These findings imply that DAC/IDC-P may have higher glucose metabolic and raise interest in targeting membrane GLUT1 as a novel anticancer strategy for DAC/IDC-P and other prostate cancer with high glucose metabolism.