Breast cancer and oxidative stress in chemotherapy

ABSTRACT

Objective: This revision characterizes the biomarkers used for analysis of the development of oxidative stress produced during breast cancer chemotherapy. Materials and methods: A search of articles indexed in digital databases (Lilacs, Bireme, PubMed, Scielo and digital libraries), along with publications printed as books, periodicals and articles not available online, in the period from 1979 to 2009. Conclusion: Reactive oxygen and nitrogen species are produced, principally, during aerobic metabolism; however, its synthesis can be exacerbated or antioxidant defense reduced or more usually, both conditions can occurr in many pathophysiologic situations, leading to a net reactive species yelded. This unbalance is defined as oxidative stress. Stress biomarkers can be defined as predictive indicators able to detect in vivo oxidative damage and can be subdivided into antioxidant and pro-oxidants. To verify the antioxidant system, it is possible to analyze the superoxide dismutase enzymes, catalase and glutathione, along with vitamins A, E, C and glutathione among others. The analysis of pro-oxidants can be made through the verification of protein nitration and oxidation, heat shock proteins, lipoperoxidation, formation of aldehydes for malondialdehyde tests, 4-hydroxynonenal, oxidized LDL and isoprostanes or for chemiluminescent techniques. Advances in cancer detection through the identification of potential biomarkers consist of a promising strategy for the prevention and early identification of this pathology.