RESUMO
BACKGROUND: Oxidative stress has a potential role in carcinogenesis. Anti-oxidant enzymes have a neutralizing effect on both cancer initiation and progression. We aimed to assess the oxidant and anti-oxidant levels of pediatric cancer patients and to compare the levels in healthy controls. MATERIALS AND METHODS: The study involved 105 pediatric cancer patients (40 undergoing chemotherapy, 65 survivors) and 40 healthy children. The serum total oxidant status (TOS) and total anti-oxidant status (TAS) were measured. RESULTS: The oxidative stress index was significantly lower in pediatric cancer patients compared to the levels in the controls (0.20 ± 0.07 vs. 0.26 ± 0.10; P = 0.001). The mean serum TAS level was significantly higher in patient groups compared to the level in the control (1.87 ± 0.48 vs. 1.63 ± 0.32 mmol/L, P = 0.001). The TAS level of children with cancer in survivors was also found to be significantly higher compared to the levels in the control group (1.85 ± 0.45 vs. 1.63 ± 0.32 mmol/L, P = 0.005). Radiotherapy, surgery, relapsed disease, presence of metastases, and receiving enteral nutritional support caused no change in the TAS/TOS level. CONCLUSION: It has been revealed for the first time that the serum total anti-oxidant level was high in children undergoing chemotherapy and the survivor group as well. Moreover, the oxidative stress index was low in children with cancer. Longitudinal prospective studies are needed to reveal the alterations in oxidant status among children with cancer.
