Selenium, Vitamin E Dont Prevent Prostate Cancer

BOSTON—Secondary analyses of two randomized controlled trials and supportive epidemiologic and preclinical data indicated the potential of selenium and vitamin E for preventing prostate cancer. The randomized, placebo-controlled trial (Selenium and Vitamin E Cancer Prevention Trial [SELECT]) found selenium or vitamin E, alone or in combination do not prevent prostate cancer in a population of relatively healthy men (JAMA. 2009;301(1)) (DOI:10.1001/jama.2008.864).

A total of 35,533 men from 427 participating sites in the United States, Canada and Puerto Rico were randomly assigned to four groups (selenium, vitamin E, selenium + vitamin E and placebo) in a double blind fashion between Aug. 22, 2001, and June 24, 2004. Oral selenium (200 µg/d from L-selenomethionine) and matched vitamin E placebo, vitamin E (400 IU/d of all rac--tocopheryl acetate) and matched selenium placebo, selenium + vitamin E, or placebo + placebo for a planned follow-up of minimum of seven years and a maximum of 12 years.

As of Oct. 23, 2008, median overall follow-up was 5.46 years. Hazard ratios for prostate cancer were 1.13 (n=473) for vitamin E, 1.04 (n=432) for selenium, and 1.05 (n=437) for selenium + vitamin E vs 1.00 (n=416) for placebo. There were no significant differences (all P>0.15) in any other prespecified cancer end points. There were statistically nonsignificant increased risks of prostate cancer in the vitamin E group (P=0.06) and type 2 diabetes mellitus in the selenium group (relative risk, P=0.16) but not in the selenium + vitamin E group.