July 24, 2001

Vitamin E and Selenium to be Tested
As Prevention Agents for Prostate Cancer

UCSD to Enroll Men in Largest-Ever National Prostate Cancer Prevention Trial

Healthy men age 55 and older are needed for the largest-ever national prostate cancer prevention study, launched today by the National Cancer Institute (NCI) and UCSD School of Medicine, which joins a network of research sites coordinated by the Southwest Oncology Group (SWOG).

The Selenium and Vitamin E Cancer Prevention Trial, or SELECT, seeks to learn if these two dietary supplements can protect against prostate cancer, the most common form of cancer, after skin cancer, in men. In recent years prostate cancer rates in the US have soared, accelerating even more rapidly than rates of breast cancer.

More than 400 sites in the United States, Puerto Rico, and Canada are participating in SELECT, which will take up to 12 years to complete. The San Diego site expects to be one of the largest, with enrollment of nearly 2,000 men out of the total of 32,400 men who will be involved at all sites.

“SELECT is the first study designed to look directly at the effects of vitamin E and selenium, both separately and together, in preventing prostate cancer,” said Robert Langer, M.D., MPH, professor of family and preventive medicine, a member of the UCSD Cancer Center, and principal investigator for SELECT in San Diego. “Previous research involving vitamin E and selenium suggested that these common nutrients might prevent prostate cancer, but we don’t know for sure. SELECT will provide the answer.”

"SELECT offers a special opportunity to link long-term prevention studies for men and women in San Diego County,” he added. “It will look at the possibility of preventing prostate cancer, the major cancer that strikes older men. Together with our ongoing Women's Health Initiative (WHI) study, which seeks ways to prevent breast cancer, SELECT will help us understand how to prevent the leading cancers in both sexes.”

The UCSD WHI center, also directed by Langer, is the largest in the west, with over 5600 women involved.

“We hope to have a similar role in SELECT, enrolling as many as 2000 men, including spouses of our WHI ladies. In the multi-cultural setting of San Diego, the combination of SELECT and the WHI offers the opportunity to look at how culture, family relationships, age and gender affect who does, and who doesn’t, get cancers, heart attacks and other major health problems such as Alzheimer's disease," said Langer.

During this year alone, prostate cancer will be diagnosed in about 198,100 Americans and more than 31,500 men are expected to die of the disease. In California, in 2001,17,500 new cases of prostate cancer are expected, with an additional estimate from the American Cancer Society that 2,800 Californians will die of the disease this year. Risk factors for prostate cancer include being over age 55, being black, or having a father or brother with prostate cancer.

“It is crucial that men of all races and ethnic backgrounds participate in SELECT,” said Leslie Ford, M.D., associate director for clinical research in NCI’s Division of Cancer Prevention. “And since African-American men have the highest incidence of prostate cancer in the world, we especially encourage them to consider joining this trial.” The disease also strikes black men at a younger age, so they will be eligible to enroll in the study at age 50, vs. age 55 for other racial and ethnic groups. There is no upper age limit for participation in SELECT.

“We are looking for quite a few good men to join SELECT,” said Charles A. Coltman, Jr., M.D., chairman of SWOG and director of the San Antonio Cancer Institute in San Antonio, Texas. “This study is important for the men who join, not only because they might prevent prostate cancer for themselves, but also because what we learn has the potential to benefit future generations of men.”

Selenium and vitamin E, both naturally occurring nutrients, are antioxidants. They are capable of neutralizing toxins known as “free radicals” that might otherwise damage the genetic material of cells and possibly lead to cancer. These nutrients were chosen for study because of the results of two other large cancer prevention trials.

In a study of selenium to prevent one type of non-melanoma skin cancer in 1,000 men and women, reported in 1996 *, investigators found that while the supplement did not reduce skin cancer, it did decrease the incidence of prostate cancer in men by more than 60 percent.

Another trial, published in 1998* *, in which beta carotene and vitamin E were tested to prevent lung cancer in 29,000 Finnish men who smoked, those who took vitamin E had 32 percent less prostate cancer. Neither beta carotene nor vitamin E prevented lung cancer. In fact, the men who smoked and took beta carotene were more apt to get lung cancer and die from it than men who didn’t take this supplement.

“SELECT is the critical next step for pursuing the promising leads we saw for the prevention of prostate cancer,” said Ford, who is responsible for all aspects of NCI’s involvement in SELECT. “The only way to determine the real value of these supplements for prostate cancer is to do a large clinical trial focused specifically on this disease.” Study investigators hope to recruit all the study participants during the first five years of the trial, so that each man can be followed for at least seven years.

San Diegans in the study will visit a clinical trial office in either La Jolla or Chula Vista once every six months. Upon enrollment, they will be assigned by chance to one of four groups. One group will take 200 micrograms of selenium daily plus an inactive capsule, or placebo, that looks like vitamin E. Another group will take 400 milligrams of vitamin E daily along with a placebo that looks like selenium. A third group will take both selenium and vitamin E. And a final group will be given two placebos.

Men who join SELECT will not need to change their diet in any way, but they must stop taking any supplements they buy themselves that contain selenium or vitamin E. If participants wish to take a multivitamin, SWOG will provide, without charge, a specially formulated one that does not contain selenium or vitamin E.

Men may be able to participate in SELECT if they:

For more information about the SELECT study:
Call the UCSD SELECT office at (858) 622-5774

For more information about prostate cancer:

Four pharmaceutical companies are providing selenium and vitamin E capsules and multivitamins for the study: Roche Vitamins Inc., Parsipanny, N.J.; Sabinsa Corporation, Piscataway, N.J.; Nutricia Manufacturing USA Inc., Greenville, S.C.; and BioAdvantex Pharma Inc., Mississauga, Ontario, Canada.

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Media Contact: Sue Pondrom
619-543-6163 or spondrom@ucsd.edu

*Clark LC, Combs GF Jr, Turnbull BW, et al. Effects of selenium supplementation for cancer prevention in patients with carcinoma of the skin. A randomized controlled trial. Nutritional Prevention of Cancer Study Group.JAMA 276:1957-1963, 1996.

** Heinonen OP, Albanes D, Huttunen JK, et al. Prostate cancer and supplementation with alpha-tocopherol and beta-carotene: incidence and mortality in a controlled trial.J Natl Cancer Inst 90:440-6, 1998.

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