The most commonly quoted study showed that selenium supplementation at 200mcg per day decreased your risk of developing prostate cancer to one third of that of men on placebo. This study was initially designed to look at skin cancers, but was extended to cover other cancers after no improvement was seen in that group. In the same study B-carotene increased the risk. The effect of vitamin E and beta carotene on the incidence of lung cancer and other cancers in male smokers. Most men with prostate cancer will not have symptoms in the early stages, when the cancer is still curable.
Some men have symptoms.
These symptoms are not specific for prostate cancer. The normal level is less than 4 nanograms per ml. When prostate cancer develops the level of PSA in the blood rises. PSA is the most accurate detector of any cancer test. Usually eight biopsies are taken.