Breast cancer is one of the most common malignancies in women with the highest mortality rate in women. Oxidative stress characteristics play a large role in the risk factor of tumors. In this study, we measure the oxidative stress indices of malondialdehyde(MDA), Total antioxidant capacity(TAC) in women with breast cancer compared to healthy subjects.This case-control study was performed on 30 women with a definitive diagnosis of breast cancer and 30 healthy women. The subjects were matched in terms of age and sex and then blood samples were taken from them and collected in vials EDTA .Oxidative stress was measured by spectrophotometry. MDA level was significantly higher in cases (2.48± 0.73 ) compared to controls (1.4± 0.63 (. In contrast, there were lower TAC levels in cases compared to controls and was statistically significant . The data showed that higher MDA levels in BC patients than in the control group. The results suggest that increased serum MDA and decreased TCA activity may be due to oxidative stress, which may play an important role in BC formation. پرونده مقاله