Background: Oncometabolites provide a new approach towards the diagnostics and prognosis of the clinical progress of prostate cancer (PCa). This study is about the diagnostic and predictive value of a panel of urinary oncometabolites (ethanolamine, kynurenine, β-alanine, α-alanine, leucine, isoleucine, γ-aminobutyric acid, and sarcosine) and correlation with prostate-specific antigen (PSA) and Gleason score in patients diagnosed with prostate cancer.
Methods: The participants in this cross-sectional study were divided into PCa group (101 patients who matched the including criteria, average age 71) and control group (52 individuals, with no evidence of malignancy, without oncological and other chronic diseases, and without prostate gland pathology, average age 40). The criteria to be included in the PCa group were as follows: i) being diagnosed with prostate cancer, based on digital rectal examination (DRE), prostate ultrasound investigation, or biopsy; ii) not being subjected to a surgical or any other treatment; iii) not having any other concomitant oncological diseases, renal failure, diabetes mellitus. The urinary concentration of the selected metabolites was established through high-performance liquid chromatography with tandem mass spectrometry detection (HPLC-MS/MS).
Results: The comparison of both groups established a significantly different elevated concentration of ethanolamine, sarcosine and kynurenine, and a significantly different decreased concentration of β-alanine and isoleucine in PCa group. No changes of the values were detected in the PCa group with PSA levels below and above 10 ng/mL and Gleason score below and above 6 (p > 0.05). To test whether combination of several variables is more powerful in discriminating between PCa and control group multiple logistic regression analysis was performed. A model including ethanolamine, sarcosine, kynurenine, β-alanine, and isoleucine demonstrated negative predictive power (NPP) 76.2% and positive predictive power (PPP) 81.8%.
Discussion: Urinary concentrations of ethanolamine, sarcosine, kynurenine, β-alanine, and isoleucine in PCa group differ significantly from that of control group. New expanded population studies are needed to discuss our results.
Keywords: Prostate cancer; biomarkers; liquid chromatography with tandem mass spectrometry; oncometabolites.