Abstract
The selenium levels in the serum, malignant tissue, and normal tissue samples of gastrointestinal cancer patients as well as the daily urinary selenium output were measured in this study. Serum selenium levels of cancer patients were significantly lower than those of the control groups which consisted of surgical patients without cancer, age-matched non-hospitalized patients, and healthy young volunteers. Daily urinary outputs of selenium were not significantly different, however, between cancer patients and surgical patients without cancer. In patients with malignant diseases, the mean selenium concentration was higher in malignant tissues than in the normal adjacent tissues. Tissue selenium concentrations were reduced significantly in patients with malignant diseases compared with patients with benign ones. Serum selenium levels were lower in patients with regional or distant involvement; however, there was no correlation between tissue selenium concentration and the clinical stage of the tumor.
