EFFECTS OF SURGICAL REMOVAL OF LUNG-CANCER ON TOTAL PLASMA ANTIOXIDANT CAPACITY IN LUNG-CANCER PATIENTS

Previous evidence suggests that malignant tumors cause an oxidative bu rden to human antioxidative defense systems. We followed the plasma to tal radical-trapping antioxidant parameters (TRAP) and their main anti oxidant components (alpha-tocopherol, uric acid, protein sulfhydryl gr oups, and unidentified antioxidant proportions) in 13 lung cancer pati ents and 7 control patients scheduled for thoracotomy. Plasma samples were collected 9 times during a 5 month follow-up period in the cancer patients. The objective of the study was to evaluate the effects of s urgical removal of lung cancer on human plasma total antioxidant capac ity. A significant reduction of plasma TRAP (period effect of ANOVA, p =0.0006) and its components appeared in both groups during the first postoperative day. This decrease was due to reduction of ascorbate(p=0 .002) alpha-tocopherol (p=0.0001) and urate (p=0.05) concentrations. A t 3 and 5 months after the surgical removal of the tumor there was an augmentation in plasma TRAP concentrations (p=0.02, 3 months;p=0.07,5 months). This was mainly due to the increases in plasma yet as unident ified antioxidant components (UNID) and protein SH-groups. The data in dicates that, first, thoracotomy itself causes a reduction in plasma T RAP during the early hours after operation, and secondly surgical remo val of lung cancer increases plasma TRAP concentrations compared to th e baseline values possibly reflecting the relief of oxidative stress c aused by malignant tumors.