Largest Study of Vitamin E and Selenium in Prostate Cancer Launched

The National Cancer Institute (NCI) and the CommunityCancer Research Consortium (part of the Southwest Oncology Group [SWOG]) havelaunched a major study examining the roles of vitamin E and selenium in theprevention of prostate cancer. The Selenium and Vitamin E Cancer PreventionTrial, or SELECT, is expected to involve more than 32,000 men and will be thelargest study of its kind. It is expected to require 12 years to complete.

"SELECT is the first study designed to look directly at the effects ofvitamin E and selenium, both separately and together, in preventingprostate cancer," said Patrick Flynn, MD, an oncologist/hematologist inprivate practice and principal investigator for the Metro-MN Community ClinicalOncology Program in Minneapolis, one of the sites for SELECT. "Previousresearch involving vitamin E and selenium suggested that these nutrients mightprevent prostate cancer, but we don’t know for sure. When SELECT is finished,we will know whether these supplements can prevent prostate cancer."

The new study is being conducted at more than 400 locations in the UnitedStates, Canada, and Puerto Rico. Although investigators will primarily studyhealthy men who are 55 years of age or older, African-Americans as young as age50 will be enrolled in light of the higher incidence and earlier onset ofdisease in this population.

A Few Good Men

"It is crucial that men of all races and ethnic backgrounds participatein SELECT," said Leslie Ford, md, associate director for clinical researchin NCI’s Division of Cancer Prevention. "And since African-American menhave the highest incidence of prostate cancer in the world, we especiallyencourage them to consider joining this trial."

Clinical Trial History

In a study of selenium to prevent nonmelanoma skin cancer in 1,000 men andwomen, reported in 1996, investigators found that while the supplement did notreduce skin cancer, it did decrease the incidence of prostate cancer in men bymore than 60%.

In another trial, published in 1998, in which beta-carotene and vitamin Ewere tested to prevent lung cancer in 29,000 Finnish men who smoked, those whotook vitamin E had 32% less prostate cancer. Neither beta-carotene nor vitamin Eprevented lung cancer. In fact, men who smoked and took beta-carotene were moreapt to develop lung cancer and die from it than men who didn’t take thesupplement.

"SELECT is the critical next step for pursuing the promising leads wesaw for the prevention of prostate cancer," said Dr. Ford, who isresponsible for all aspects of NCI’s involvement in SELECT. "The only wayto determine the real value of these supplements for prostate cancer is to do alarge clinical trial focused specifically on this disease." Studyinvestigators hope to recruit all the study participants during the first 5years of the trial, so that each man can be followed for at least 7 years.

Men in the study will visit one of the designated study sites once every 6months. Upon enrollment, they will be randomized into one of four groups: Onegroup will take 200 µg of selenium daily plus a placebo capsule that looks likevitamin E; another group will take 400 µg of vitamin E daily along with aplacebo that looks like selenium; a third group will take both selenium andvitamin E; and a final group will be given two placebos.

Men who join SELECT will not need to change their diet, but they must stoptaking other supplements containing selenium or vitamin E. If participants wishto take a multivitamin, SWOG will provide, without charge, a speciallyformulated one that does not contain selenium or vitamin E.

References:

For More Information

Men interested in joining the study can call the Community Cancer Research Consortium screening number at 952-993-1536 for more information and the sites involved in SELECT locally. Information about the study or prostate cancer generally can also be found through the following resources:
· In the United States (including Puerto Rico), call the NCI’s Cancer Information Service at 1-800-4-CANCER (1-800-422-6237) for information in English or Spanish. The number for callers with TTY equipment is 1-800-332-8615.
· In Canada, call the Canadian Cancer Society’s Cancer Information Service at 1-888-939-3333 for information in English or French.
· Visit NCI’s website at http://cancer.gov/select, or visit SWOG’s website at http://swog.org and choose SELECT.