Plasma total antioxidant status in breast cancer women in relation to lymph node involvement and HER-2/neu expression

Background Oxidants can act at several stages of malignant transformation. To protect against toxic effects of oxidants and to modulate physiological effects of their action organisms have developed antioxidant defence systems. Plasma total antioxidant activity (TAS) measures peroxyl-scavenging capacity of the extracellular antioxidant system. Aim The goal of this pilot study was to evaluate the plasma total antioxidant status in breast cancer women in relation to lymph node metastases and HER-2/neu expression. Materials/Methods Newly diagnosed consecutive breast cancer patients (n=26) were recruited before any treatment and matched with controls (n=24) randomly selected from benign breast disease patients. Cancer progress was established according to lymph node involvement: No or N+. HER-2/neu was considered as either negative (0 or 1+) or positive (2+ or 3+). The plasma total antioxidant status (TAS) was measured by colorimetric test (RANDOX). HER-2/neu oncogene expression was determined in breast cancer tissue using the immunohistochemical method (Hercep Test). Results The study demonstrated a significant decrease in the mean TAS level (mmol/L) in the breast cancer group (1.42 +/- 0.22) in comparison to the control group (1.56 +/- 0.18; P<0.01). The mean TAS concentration was found not to differ significantly between breast cancer subgroups in relation to the progress of the disease. Although the mean TAS concentration was not significantly different in regard to the HER-2/neu expression, there was a tendency observed towards higher TAS in the HER-2/neu negative subgroup (1.46 +/- 0.20) than in the HER-2/neu positive one (1.41 +/- 0.25). Conclusions The results of the study suggest increased consumption of plasma antioxidants in response to enhanced oxidants production in breast cancer patients. Changes in TAS level do not seem to correspond with the progress of the malignancy but might be related to HER-2/neu expression.