Tissue lipid peroxidation and antioxidant status in patients with adenocarcinoma of the breast

Background: Carcinoma of the breast, the third most common cancer worldwide, accounts for the highest morbidity and mortality. The increasing global incidence of breast cancer emphasizes the need to understand the various mechanisms involved in breast tumorigenesis. The present study was undertaken to evaluate the use of lipid peroxidation and antioxidants as biomarkers in human mammary tumors. Methods: The extent of lipid peroxidation as evidenced by the formation of thiobarbituric acid reactive substances (TBARS), lipid hydroperoxides (LOOH) and conjugated dienes (CD) as well as the status of the antioxidants superoxide dismutase (SOD), catalase (CAT), reduced glutathione (GSH), glutathione peroxidase (GPx) and glutathione- S-transferase (GST) in tumor tissues and adjacent normal tissues of 30 breast cancer patients was estimated. Results: Lipid peroxidation in breast cancer tissues was enhanced compared to the corresponding adjacent uninvolved tissues. This was accompanied by significant elevation in both enzymic and non-enzymic antioxidants. Conclusions: We suggest that upregulation of antioxidants induced by oxidative stress confers a selective growth advantage to tumor cells over their adjacent normal counterparts.