Erythrocyte glutathione peroxidase in patients with colon cancer.

Erythrocyte activity of glutathione peroxidase (GSH-Px) was measured in 26 patients with colon cancer and in 26 sex, age, height and weight matched controls. The patient group had a lower mean GSH-Px activity than the control group (p < 0.001). No correlation was found between glutathione peroxidase activity and sex, age, height, or weight, or between glutathione peroxidase activity and duration of the disease. The inverse correlation between the activity of this enzyme and the extent of the disease may be caused by a decreased absorption of selenium from the diseased colon. The significance of decreased GSH-Px in patients with this disease is unknown, but the possibility exists that this may further increase their risk of developing colonic cancer.