[Selenium content and glutathione peroxidase in erythrocytes from different populations in areas with high and low mortality of esophageal cancer].

The effects of selenium (Se) concentration and glutathione peroxidase (GSH-Px) activity in the development of esophageal cancer was studied. The results indicated that there were no significant differences in Se level (P greater than 0.2) and GSH-Px activity (P greater than 0.1) in the normal subjects from areas with high and low esophageal cancer mortality. In an area with high esophageal cancer mortality, the Se level and GSH-Px activity of the normal, mild hyperplasia, severe dysplasia and cancer groups decreased gradually. There was a significant difference in the erythrocyte Se concentration of the normal and severe dysplasia groups (P less than 0.03). Erythrocyte Se concentration and GSH-Px activity were significantly lower in the cancer group than in the normal group (P less than 0.001; P less than 0.03). The findings suggest that low erythrocyte Se level and GSH-Px activity were the results of carcinogenesis rather than a cause.