Renal cell carcinoma affects RedOx homeostasis and selenium content

With early detection and improved diagnostics Renal cell carcinoma (RCC) incidence in Latvia has increased over the last 20 years. Although overall survival rates are improving, they remain relatively low compared to the rest of the world. The aim of this study was to evaluate RedOx homeostasis factors that play a role in increased mortality rates in our population. This prospective study conducted between April 2016 and July 2018 includes 72 Clear-cell RCC subjects who underwent nephrectomy and 30 healthy controls. Blood was collected for antioxidant and peroxidant analysis the day prior to surgery. Selenium (Se) deficiency was defined as level <85 μg/l. Data were analyzed using nonparametric tests. Statistical significance was defined as p<0.05. Se level was lower in the RCC group compared to the control group, 81.5 vs 100.8 (p=0.001, r=0.414). Total antioxidant status (TAS) and Glutathione peroxidase (GPx) levels were lower in RCC group: 1.81 vs 2.06 (p<0.001, r=0.651) and 7978.0 vs 9087.5 (p=0.002, r=0.386) respectively. No difference was observed in Superoxide dismutase (SOD) level between two groups, 1811.8 vs 1852.0 (p= 0.917, r=0.015). Lipid peroxidase derived Malondialdehyde/4-Hydroxynonenal (MDA/4-HNE) levels were higher in the RCC group vs controls, 4.92 vs 3.17 (p=0.001, r=0.510). Se level was higher is the Low grade (LG) RCC group compared to High grade (HG) group, 84.0 vs 68.0 (p=0.047, r=0.338). SOD level was lower in LG compared to HG group, 1741.0 vs 1927.0 (p=0.019, r=0.396). No difference was found in any of the RedOx analytes between different RCC stages. Se deficit was seen in 57.4% of RCC subjects compared to 23.3% of controls (p=0.002, OR 4.4, 95%CI 1.7 to 11.7). RedOx homeostasis is disrupted in RCC patients. It is affected by tumor aggressiveness but not the stage. Se deficiency may play a role in RCC pathogenesis.