These findings support the need for large-scale trials. They cannot, however, serve as a basis for determining dietary selenium requirements at this time. This 9-year study is exactly what the authors of the book said needed to be done to validate the anticancer benefits of selenium. The fact that this positive and well recognized study was omitted seriously questions the credibility of this 512-page book. The authors omitted studies indicating that selenium may be effective as an adjunctive cancer therapy.
Tumors require new blood vessels to sustain their rapidly proliferating cancer cells.
Substances that inhibit the formation of new blood vessels are called antiangiogenesis agents, and these substances are being extensively studied as potential cancer therapies. Selenium's anti-angiogenesis property may be one reason why is has been shown to reduce cancer mortality rates in humans already diagnosed with cancer. In Germany, selenium is being used as an adjunctive cancer therapy. Side effects were not reported. Analysis of the immune system reveal a stimulation of B19 lymphocytes and natural killer cells.