A nationwide study of more than 35,000 men older than 50 has determined that taking vitamin E and selenium supplements has no effect on decreasing the occurrence of prostate cancer.
In fact, it showed just the opposite, that the vitamin E supplements contributed to a small, statistically insignificant increase in the occurrence of prostate cancer. And for the same range of men, the addition of selenium in their diets contributed to a small, statistically insignificant increase in the occurrence of adult-onset diabetes.
All men in the Selenium and Vitamin E Cancer Prevention Trial (Select) are asked to stop taking the supplements immediately.
Locally, the University of Colorado Cancer Center has roughly 930 men participating in the select study, the third-largest group of subjects in the country.
In a recorded telephone message at the CU Cancer Center’s office, participants are told they will receive a letter by Nov. 7 telling them what to do.
“We are going to stay on our contact schedule,” said Pam Rosse, the select-program manager for CU. “We will have everyone bring their supplements back in to be returned to the pharmacy.”
Rosse said the announcement Monday was made after a routine and ongoing review of statistical data.
The study began in 2001 and was scheduled to run until 2012.
“When the study was announced, people signed up much faster than expected. There also has been a relatively low dropout rate, so they’ve been collecting data much faster than they expected,” she said.
The participants were assigned to one of four groups: taking selenium along with vitamin E; selenium with a vitamin E placebo; vitamin E with a selenium placebo; and selenium and vitamin E placebos.
The process is called blinding or masking. Rosse said the men will be told in the near future which group they belonged to.
The $114 million study, funded by the National Cancer Institute, hoped to confirm or disprove a 1998 study in Finland that showed more than 29,000 male smokers who took vitamin E to prevent lung cancer had 32 percent fewer occurrences of prostate cancer.
Prostate cancer is second to skin cancer as the most prevalent form of cancer among males in the United States. This year, there will be an estimated 186,000 new cases of prostate cancer, causing 28,660 deaths, according to the NCI.
Mike McPhee: 303-954-1409 or mmcphee@denverpost.com
