[Serum selenium contents in cancer patients]

The conclusions were confirmed by determining the serum Selenium levels in 2099 cancerous of non-cancerous patients as follows: 1) The mean serum Selenium levels of males is significantly higher than in females. 2) Serum Selenium levels tend to decrease with age. 3) The serum Selenium levels of cancerous patients is significantly lower than in non-cancerous patients. 4) No significant difference in the serum Selenium levels was observed between cancerous patients with and without metastasis. Most patients without metastasis are free from cancer after surgery, so the low serum Selenium level in cancerous patients may not be induced by the tumor but was present before the tumor.