Diagnostic significance and utility of circulating redox biomarkers in patients with gastric cancer - preliminary study.

Background: This study aimed to evaluate the redox status, antioxidant barrier, and oxidative damage to proteins, lipids, and DNA in patients with gastric cancer (GC). We are also the first to assess the diagnostic utility of redox parameters in patients with GC with respect to histopathological parameters.

Methods: Fifty patients with gastric cancer and 50 healthy controls matched for sex and age were included in the study. The antioxidant barrier, redox status, and oxidative damage products were measured in serum/plasma samples using colorimetric or spectrophotometric methods.

Results: The activity of superoxide dismutase - SOD ( < 0.05) was significantly higher, whereas the activities of catalase - CAT ( < 0.0001), glutathione peroxidase - GPx ( < 0.0001), glutathione reductase - GR ( < 0.0001), and reduced glutathione - GSH ( < 0.05) were considerably lower in GC patients than in the control group. The levels of total oxidant status - TOS ( < 0.0001), oxidative stress index - OSI ( < 0.0001), advanced oxidation protein products - AOPP ( < 0.0001), ischaemia modified albumin - IMA ( < 0.01), lipid hydroperoxides - LOOH ( < 0.0001), 8-IsoProstane - 8-Iso-P ( < 0.0001), and DNA/RNA ( < 0.0001) were significantly higher, and the levels of total antioxidant capacity - TAC ( < 0.0001) and total thiols ( < 0.0001) were considerably lower in patients compared to the healthy controls. Some redox parameters are characterized by high AUC values in patients with differentiated GC according to histopathological parameters.

Conclusions: Gastric cancer is strongly linked to a systemic redox imbalance and increased oxidative damage to proteins, lipids, and DNA. Redox biomarkers are potential diagnostic indicators of gastric cancer advancement.