Health and Prostate

At this time, there is not an approved chemoprevention agent for prostate cancer, though this is an active area of study. Finasteride is a 5a-reductase inhibitor approved for benign prostatic hyperplasia (BPH) and male pattern baldness. Prostate cancer has never been reported in men who have a deficiency in the enzyme 5a-reductase. In trials, finasteride has been shown to prevent prostate growth and may decrease prostate-specific antigen (PSA) levels. The Prostate Cancer Chemoprevention Trial (PCPT) is testing finasteride as a chemoprotective agent. PCPT has enrolled more than 18,000 men and assigned them to either finasteride 5 mg per day or placebo. The primary end point of this study is the number of biopsy-proven prostate cancers in finasteride patients versus in placebo patients, and the results are expected in 2004. Saw palmetto is an herbal therapy used to treat benign prostatic hyperplasia (BPH) symptoms and is thought to be a 5a-reductase inhibitor. Currently there are no published in vivo or outcomes studies regarding saw palmetto as a chemopreventative. One in vitro study showed that saw palmetto berry extract inhibited growth in some human prostatic cell lines. A recent study suggests that selenium may decrease the incidence of prostate cancer. The Nutritional Prevention of Cancer trial randomly assigned 927 men to selenium 200 mcg per day or placebo. Twenty-two men in the selenium group developed prostate cancer compared to 42 men in the placebo group. Favorable response was found in men with low baseline selenium levels (123.2 ng/mL) and a low baseline PSA (< 4 ng/mL). Although this is significant, there are limitations to these results, and further study is required with selenium in prostate cancer. The SELECT (Selenium and Vitamin E Cancer Prevention Trial) is now in progress and is expected to have more reliable data regarding selenium in prostate cancer prevention.