Selenium and Vitamin E Cancer Prevention Trial (SELECT) Home Page

The SELECT Data and Safety Monitoring Committee (DSMC) met in September 2008 to review the data to date. Thanks to each and every participant, enough data were available to make a decision about the effectiveness of the Study Supplements. The data showed that 200 mcg of selenium and 400 IUs daily of vitamin E do not prevent prostate cancer. Investigators from the study leadership and the National Cancer Institute agreed with the DSMC’s findings. Participants in SELECT should stop taking their Study Supplements.

SELECT is not over. There is valuable information to be gained by continuing participant follow-up. The data to date suggest, but do 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. We emphasize that these findings are not proven. We will learn more about the effects of the Study Supplements as we continue to monitor our participants’ health. Participant safety is our priority.

The study site staff will gather information on participants’ current health and medical information at study site visits. As one of the largest medical studies of men, SELECT will help answer many critical questions about men’s health and will assist scientists in the future.

Participants will receive a letter about this transition from the study leadership. The letter will be mailed to them by their local study site. Continue to check this website for periodic updates. If you are a participant in SELECT, you can contact your Study Site for more information. Contact information for your Study Site can be found in the list of SELECT Study Sites.

Thanks to all the participants on SELECT, we now know that selenium and vitamin E do not prevent prostate cancer. This important public health message is a result of over 35,000 men participating in SELECT. The SELECT National Participant Advisory Board and the leadership of SELECT appreciate each participant’s commitment. The best way for participants to maximize their contribution is to continue to participate in SELECT.

Frequently Asked Questions and Responses

1. Why did SELECT get these results, when previous studies suggested that selenium and vitamin E are helpful?
Answer: The incidence, or rate of occurrence, of prostate cancer in the other studies was not the primary focus or endpoint. Men in those studies were not screened with the blood test of PSA (prostate specific antigen) and DRE (digital rectal exam) regularly. SELECT is the only study where the question of whether either selenium or vitamin E would prevent prostate cancer was asked directly and where prostate cancer was the primary endpoint.

2. Should you avoid taking a multivitamin that contains either or both of these supplements?
Answer: No, as long as you take only one multivitamin a day.
3. Since vitamin E and selenium don’t work, is there anything else you can do to help reduce your risk of prostate cancer?
Answer: The Prostate Cancer Prevention Trial (PCPT) showed that taking the drug finasteride reduces the risk of prostate cancer by 25%. You should discuss with your doctor whether it makes sense for you to take finasteride. Finasteride may also be prescribed for men with lower urinary tract symptoms due to prostate enlargement (BPH).

4. Why do we still want to collect data from SELECT participants if we already know the results?
Answer: These supplements, selenium and vitamin E, may have biologic effects even after you stop taking them. We want to continue to collect data to learn of any long-term effects of these supplements on the risk of prostate cancer and other diseases including cardiovascular disease and other cancers.
5. Is there any value or harm if you eat foods high in selenium or vitamin E?

Answer: There are no proven benefits or harms if you eat foods high in selenium or vitamin E.

What is SELECT?
The Selenium and Vitamin E Cancer Prevention Trial (SELECT) is a research study to determine if selenium and vitamin E can help prevent prostate cancer. SELECT is funded by the National Cancer Institute and coordinated by the Southwest Oncology Group. Over 35,000 men, from a variety of ethnic groups, including 14% African American, 5% Hispanic, 1% Hispanic African American, and 1% Asian, from over 400 Study Sites in the United States, Puerto Rico, and Canada are participating in SELECT.

What more information about prostate cancer?
To find out more about prostate cancer risk factors, prevention, screening, diagnosis, treatment, or clinical trials, please click on the links provided or contact the National Cancer Institute's Cancer Information Service at 1-800-4-Cancer (1-800-422-6237) or TTY: 1-800-332-8615. In Canada, call the Canadian Cancer Society’s Cancer Information Service at 1-888-939-3333.