Cancer Chemoprevention Research and Programs

SELECT

The Selenium and Vitamin E Clinical Trial is an ongoing large trial across the country, in which daily supplements of selenium and/or vitamin E are being tested to reduce the risk of prostate cancer. Colorado is one of the largest of the clinical centers for this trial. (PI David Crawford, funded by NCI).

On Oct. 27, 2008, the study leadership at the National Cancer Institute and the Southwest Oncology Group decided that it has enough data to be able to tell participants to stop taking the study supplements. However, SELECT will continue, because there is valuable information gained from their continued participation in the study because more than 35,000 men are involved. It is one of the largest medical studies of men. Participants will receive a letter around Oct. 31, 2008, providing more information about how to continue.

The data shows it is unlikely that selenium or vitamin E will prevent prostate cancer. The data also suggests, but does not prove, that vitamin E may slightly increase the chance of getting prostate cancer, and that selenium may increase the chance of getting diabetes mellitus. The study leadership emphasizes that these findings are not proven, and they will learn more about the effects as they continue to monitor participants' health.

Why Participants Should Continue to Participate

Keep in mind that while SELECT's primary purpose was to see what effect, if any, taking these supplement has on prostate cancer, the study is also looking at relationships between the supplements and the incidence of:

• lung cancer
• colon cancer
• heart disease
• eye health
• diabetes

Even though participants will not continue taking the supplements, over the next three years participants will be followed for long-term outcomes of taking them during the previous five years. The study's results in 2011 will be more meaningful if participants agree to remain "blinded" for the duration of the trial.

For more information, please contact Pam Rosse , MS, RN, CNS, 303-724-1678. However, as there are 930 active SELECT participants in Colorado, she may not be able to answer your calls individually.

Polyp Prevention Trials

Colorado collaborates with other cancer centers in the conduct of trials to test the effects of various nutrients and medications on reduction of risk for colorectal cancer. We have conducted several such trials in past years, testing effects of aspirin, calcium, and folic acid. Studies are now underway to test the effects of daily selenium supplements on polyp formation. (PI Dennis Ahnen, funded by NCI)