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Selenium, Vitamin E Don’t Prevent Prostate Cancer

CancerWise - April 2009

By Tomise Martin

An international study has found that two nutritional supplements, the chemical element selenium and vitamin E, do not prevent prostate cancer when taken alone or together.

Prostate cancer is the second leading cause of cancer death in the United States. The American Cancer Society estimates that more than 180,000 American men were diagnosed with prostate cancer in 2008, and nearly 29,000 died from the disease.

African-American men have a 60% higher incidence of prostate cancer and are twice as likely to die from the disease as Caucasian men in this country.

Supplements tested in major study

One of the largest prostate cancer prevention studies ever, the Selenium and Vitamin E Cancer Prevention Trial, or SELECT, opened in 2001. More than 35,500 healthy men from 427 sites in the United States, Canada and Puerto Rico participated.

They received one of four regimens:

  • Selenium and placebo
  • Vitamin E and placebo
  • Selenium and vitamin E
  • Two placebos

The supplements showed no benefit in preventing prostate cancer.

However, men who received:

  • Vitamin E had a slightly higher risk of prostate cancer
  • Selenium had a slightly higher risk of type 2 diabetes

But these trends may be due to chance and were not observed in the group taking both selenium and vitamin E, according to the study’s national coordinators Scott Lippman, M.D., chair of Thoracic/Head and Neck Medical Oncology at
M. D. Anderson, and Eric Klein, M.D., of the Cleveland Clinic.

Researchers examine long-term effects

The study supplements were discontinued last year upon the recommendation of an independent data and safety monitoring committee. Investigators will continue monitoring participants for three years to determine any possible long-term effects of the agents and to better understand prostate cancer.

M. D. Anderson resources:

© 2015 The University of Texas MD Anderson Cancer Center