Prostate cancer is the second most common cause of cancer death in Western male populations. It is estimated that about 18 per cent of American men will develop prostate cancer during their lifetime. Some researchers believe that many more have the beginnings of prostate cancer, but die from other causes before the cancer becomes invasive and fatal. Research has shown that the hormone DHEA (dehydroepiandrosterone) inhibits the growth of both human and rat prostate cancer cells in vitro (in test tubes). Now a team of researchers from the National Cancer Institute, the New York University School of Medicine, and the ITT Research Institute reports that DHEA confers significant protection against prostate cancer progression when given to laboratory rats as part of their diet. Their experiment involved rats which were given carcinogenic chemicals to induce precancerous lesions in the prostate. One group of rats had 1000 or 2000 mg of DHEA added to each kilogram of feed starting one week before inducing the cancer. Other groups had 2000 mg of DHEA added per kilogram of diet one week before induction, 20 weeks after induction or 40 weeks after induction. The rats received the DHEA until the experiment was concluded 13 months after cancer induction. Control rats received no DHEA. The researchers found a very significant decrease in the progression to full prostate cancer among the rats given DHEA in their diets. This effect was evident whether the DHEA was given one week before or 20 or 40 weeks after cancer induction. They conclude that DHEA or a suitable derivative may be effective in preventing the development and progression of prostate cancer in humans, but caution that more work is required to ensure the DHEA's hormonal effects (conversion to testosterone and estrogenic activity) are not detrimental.
Rao, K.V.N., et al. Chemoprevention of rat prostate carcinogenesis by early and delayed administration of dehydroepiandrosterone. Cancer Research, Vol. 59, No. 13, July 1, 1999, pp. 3084-89