Investigators from the Selenium and Vitamin E Cancer Prevention Trial (SELECT) contacted participants in November 2008 to tell them to stop taking the selenium and vitamin E pills supplied as part of the study. The study did not meet its goal of reducing the risk of prostate cancer by 25 percent. Participants had been taking the supplements for an average of five years.

The SELECT trial was started in 2001 to determine whether selenium or vitamin E alone or combined together could reduce the risk of prostate cancer. The University of Iowa was one of 400 sites that enrolled a total of 35,000 participants over three years. Participants are black men 50 years and older and white men 55 years and older at the time of enrollment. Men were randomly separated into four groups receiving different pills: two placebo pills; selenium and placebo; vitamin E and placebo; or vitamin E and selenium.

The data collected up to September 2008 hints, but does not prove, that vitamin E may slightly raise the chance of developing prostate cancer. It is also possible that selenium may increase the chance of developing adult onset diabetes. These findings were seen during a first look at the data, have not been proven by the data collected so far, and could be due to chance.

The study is not over. Participants are being asked to continue in the study for the next three years. They will be followed closely by study staff to note any effects from the supplements that may not show up for some time. This follow up period will allow staff to collect additional data that will hopefully clarify the initial findings noted above.

For more information about prostate cancer or any cancer concern, contact

Holden Comprehensive Cancer Center/Cancer Information Service
Phone: 800-237-1225
cancer-information@uiowa.edu
Walk-in: 200 Hawkins Drive, 4802 JPP
Iowa City, Iowa 52242