Evaluation of plasma non-enzymatic antioxidants in breast cancer etiology.

Objective: Oxidative stress has emerged as a major etiological factor for breast cancer. Diet derived antioxidants play an important role against oxidative stress and the aim of the present study was to examine roles of non-enzymatic antioxidants in breast cancer in India.

Methods: Plasma non-enzymatic antioxidants; beta-carotene, vitamin A, vitamin E and vitamin C were analyzed spectrophotometrically from 70 healthy female controls, 30 patients with benign breast diseases (BBD) and 125 untreated breast cancer patients (BCPT).

Results: Plasma vitamin C levels were significantly lower in patients with BBD as compared to the controls (p= 0.043). Plasma beta-carotene, vitamin E and vitamin C levels were significantly lower in BCPT as compared to the controls (p= 0.0001, p= 0.040 and p= 0.0001, respectively). Plasma vitamin A levels were significantly higher in patients with BBD and BCPT as compared to the controls (p= 0.0001 and p= 0.0001; respectively) and in BCPT as compared to patients with BBD (p= 0.030). ROC curve analysis revealed that plasma beta-carotene and vitamin A could significantly discriminate between controls and patients with BBD (p= 0.016 and p= 0.000; respectively). Plasma beta-carotene, vitamin A, vitamin E and vitamin C could significantly discriminate between controls and BCPT (p= 0.000, p= 0.000, p= 0.001and p= 0.001, respectively). Plasma vitamin E levels could significantly discriminate between patients with BBD and BCPT (p= 0.055). Odds ratio analysis revealed that, increasing levels of plasma beta-carotene, vitamin E and vitamin C were significantly associated with decreased risk of breast cancer (p= 0.0001, p= 0.003, and p= 0.0001; respectively), whereas, increased risk was linked to plasma vitamin A (p= 0.001).

Conclusions: The trends of the current study provide interesting clues to the etiology of breast cancer and suggest significance of interplay of non-enzymatic antioxidants in breast cancer. Further in-depth study is warranted to elucidate role of these antioxidants as a preventive measure.