Serum selenium and glutathione peroxidase, and plasma lipid peroxides in uterine, ovarian or vulvar cancer, and their responses to antioxidants in patients with ovarian cancer.

The concentrations of serum selenium and plasma lipid peroxides, and the activity of serum glutathione peroxidase (GSH-Px) were measured before any therapy in patients suffering from uterine, ovarian or vulvar cancer, and in association with 1-day combination cytotoxic chemotherapy of ovarian cancer following 1-week supplementation with selenium (96 micrograms/day), vitamin E (300 mg/day), selenium and vitamin E, or placebo. Patients with gynaecological cancer (N = 44) had lower serum concentration of selenium (1.15 +/- 0.04 S.E. mumol/l; P less than 0.05) and serum activity of GSH-Px (404 +/- 13 units/l, P less than 0.01) than the control subjects (N = 56; 1.25 +/- 0.03 mumol/l and 444 +/- 8 units/l, respectively). In association with cytotoxic chemotherapy selenium alone (P less than 0.05), vitamin E alone (P less than 0.05) and both of them together (P less than 0.001) decreased the plasma concentration of lipid peroxides, and the combination of selenium and vitamin E also increased the activity of serum GSH-Px (P less than 0.01). During placebo, cytotoxic chemotherapy did not affect plasma lipid peroxides but it decreased (P less than 0.001) the activity of GSH-Px. Selenium inhibited this effect. Our data suggest that antioxidative mechanisms of patients with gynaecological cancer may be defective and that treatment with selenium and vitamin E results in changes of biochemical factors related to lipid peroxidation.