Antioxidants in female breast cancer patients.

Blood levels of selenium, zinc, copper, and vitamins E and C were measured in 48 cases and 50 controls from a hospital-based case-control study bearing on breast cancer risk factors in Montpellier (France). Cellular levels of selenium and vitamins E and C were also evaluated in most of the subjects. We found that the blood and cellular levels of these antioxidants were overall higher in cases than in controls, significantly for serum zinc, plasma, and leukocyte vitamin E. The statistical significance of the difference between case and control serum Cu crude levels disappeared after adjustment for metabolically related variables. The difference was borderline significant for leukocyte vitamin C. These results were slightly modified when vitamin pill users were excluded from case and control samples. The serum zinc odds ratios computed after adjustment for related variables were significantly elevated (2.53, confidence interval: 1.34-4.78, for the highest tertile) as were those computed previously for pooled plasma vitamin E levels in a joint study.