[Dynamics of the course of neoplastic disease and status of antioxidant system]

The decreased ability to remove free radicals from organism is one of the factors which furthers the development of neoplastic process. Enzymes and substrates which can remove free radicals from organism from antioxidant barrier. The appreciation of some elements of antioxidant organism barrier in children with neoplastic disease was the study's purpose. We examined 100 children in the age from 6 months to 16 years (60 patients with malignant solid tumors and 40 healthy children as a control group). We investigated glutathione peroxidase, catalase and superoxide dismutase activities in erythrocytes. In these children we studied also catalase activity, ceruloplasmin concentration and antioxidant barrier level in plasma. We estimated antioxidant elements in patients with cancer before, during and after treatment and during remission and progression of the disease. The decrease of total antioxidant barrier was typical in introductory period of neoplastic disease. We observed the increase of superoxide dismutase and glutathione peroxidase in erythrocytes and catalase activity in plasma in children with clinical remission but we found the gradual decrease of ceruloplasmin level in plasma.