The clinical significance of serum oxidative stress biomarkers in breast cancer females

Abstract

Background: This study was conducted to evaluate the role of some serum oxidative stress biomarkers for breast cancer diagnosis, incidence and monitoring the effects of surgery and chemotherapy. Methods: A total of 35 breast cancer patients (before surgery, after two weeks of surgery and after 6 cy­cles of chemotherapy) and 35 normal healthy controls were analyzed for serum oxidative stress markers including total antioxidant capacity (TAC), malondialdehyde (MDA), total, reduced (GSH) and oxidized (GSSG) glutathione and glutathione redox status (GSH/GSSG). Results: The serum levels of MDA and GSSG were significantly higher in breast cancer patients than controls. The serum levels of GSH, TAC and GSH/GSSG ratio were significantly lower in breast cancer patients than controls. After surgery, the serum levels of MDA and GSSG were significantly decreased, while the serum levels of GSH were significantly increased, compared with their levels before surgery. Six cycles of chemotherapy showed the non-significant effect on the serum levels of the assayed biomarkers. ROC curve analysis demonstrated that MDA and GSH were superior to the GSH/GSSG ratio, TAC and GSSG. Increased levels of MDA and GSSG and reduced levels of GSH, TAC and GSH/GSSG ratio were found to significantly increase the risk of breast cancer. Conclusions: All of the assayed biomarkers can be used for prediction of breast cancer with MDA and GSH being superior to the others. MDA, GSH and GSSG were able to monitor the effect of surgery. All of the assayed biomarkers were found to be associated with breast cancer risk. None of the assayed biomarkers was able to predict the effect of chemotherapy.