Objectives: Improper balance between the production of reactive oxygen metabolites (ROMs), and antioxidative defense system have been defined as oxidative stress in various pathologic conditions. Lipids, lipoproteins and antioxidative vitamins have been associated with the risk of breast cancer. The present case-control study was conducted to investigate the status of antioxidative vitamins (A, C and E), lipids (total cholesterol; TC and triglycerides; TG), lipoproteins (high-density lipoprotein cholesterol; HDL-C and low-density lipoprotein cholesterol; LDL-C) and retinol-binding protein (RBP) in breast cancer patients. The aim of the study was to find out oxidative stress in breast cancer.
Design and methods: Plasma lipids, lipoproteins and vitamins were estimated in 54 untreated breast cancer patients of different clinical stages and in 42 age- and sex-matched controls.
Results: Plasma TC (p < 0.05), and LDL-C and TG (p < 0.01) were found to be significantly elevated among breast cancer patients as compared to the controls. On the other hand, plasma HDL-C concentration (p < 0.001) and vitamin C and E (p < 0.01) were observed significantly decreased in breast cancer patients than in the controls. The maximum changes in plasma TC, and vitamin C and E concentrations were observed in breast cancer patients with stage IV when compared with controls.
Conclusion: The study suggests that higher levels of TC and TG may play important role in carcinogenesis. Furthermore, the elevated plasma LDL-C concentration, which is more susceptible to oxidation, may result in higher lipid peroxidation in breast cancer patients. However, decreased concentrations of HDL-C and vitamin C and E are not likely to be sufficient enough to counter higher ROMs production reported earlier in breast cancer patients that may cause oxidative stress leading to cellular and molecular damage thereby resulting in cell proliferation and malignant conversions.