Thiol-disulfide homeostasis in breast cancer patients.

The aim of our study is to assess thiol-disulfide homeostasis (TDH), which is a biomarker of systemic oxidative stress, in breast cancer patients.Thirty-seven breast cancer patients and 31 age-matched healthy volunteers were enrolled in this study. Serum native thiol, disulfide, and total thiol levels and disulfide/native thiol, disulfide/total thiol, and native thiol/total thiol ratios were analyzed using a novel colorimetric method.Serum native thiol level was statistically significantly lower in breast cancer patients (350.39 ± 7.15) than in healthy controls (380.60 ± 7.35) (P = 0.008). Serum disulfide level was statistically significantly higher in breast cancer patients (24.96 ± 0.85) than in healthy controls (19.25 ± 1.34) (P = 0.002).To our knowledge, this study is the first study in the literature that investigated TDH in breast cancer patients. We have concluded that an alteration in TDH due to oxidative stress is likely to have a role in the pathogenesis of breast cancer.