Parameters of oxidative metabolism in the blood of patients with pancreatic tumors of different histotypes.

Abstract

e16697 Background: High mortality rates in patients with pancreatic tumors and especially with neuroendocrine tumors necessitate the study of their molecular features. Our purpose was the comparative analysis of the intensity of lipid peroxidation and functioning of the enzymatic unit of the antioxidant system in the blood of patients with pancreatic tumors depending on the presence of a neuroendocrine component in them. Methods: The study included 42 patients with pancreatic cancer before the treatment and 22 donors. Parameters of lipid peroxidation (LPO) - the content of malondialdehyde (MDA) and diene conjugates, the activity of superoxide dismutase (SOD) and catalase were measured in the plasma and red blood cells, and the content of SOD1, SOD3 and catalase were measured in the blood plasma by ELISA. The results were analyzed depending on the histotype of removed tumors: pancreatic neuroendocrine tumors (n = 12), pancreatic adenocarcinoma (n = 9), pancreatic adenocarcinoma with a neuroendocrine component from 1% to 10-30% (n = 21). Results: The most pronounced changes in the blood oxidative status relative to the group of donors were observed in neuroendocrine cancer: an increase in plasma MDA levels by 30% (p = 0.006), diene conjugates in plasma and red blood cells by 2.6 and 2.9 times (p≤0.0003), a decrease in SOD and catalase activity in red blood cells by 39.7%, and 46.5% (p = 0.000000), reduced (by 20%, p = 0.047) plasma catalase activity and the minimal ratio of activity to content of both antioxidant enzymes (37.2% and 54.8% of donor levels, p < 0.0002). Conclusions: The LPO intensification most typical of neuroendocrine cancer is promoted by more significant inhibition of enzymes of the first-line antioxidant defense in red blood cells and decreased plasma catalase activity, compared to the values in adenocarcinoma.