Selenium-Prostate Cancer Risk Link Questioned

SEATTLEA multi-center study, including the University of Washington and Bostons Tufts University, found serum selenium levels did not correlate with risk of cancer, except in people with high intakes of vitamin E, multivitamin users or smokers. Published in the January issue of the American Journal of Clinical Nutrition (85, 1:209-217, 2007), the results were from a nested case-control study performed within the screening arm of the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial.

Researchers compared serum selenium levels in prospectively collected samples to those in 724 incident prostate cancer case subjects and 879 control subjects; they frequency-matched for age, time (since initial screen) and year of blood draw. The men were followed for up to eight years.

Results showed serum selenium was not associated with prostate cancer risk; however, higher serum selenium was associated with lower risks in men reporting a higher-than-median vitamin E intake, as well as in multivitamin usersor for the highest, compared with the lowest, quartile of selenium. Also, in smokers, high serum selenium concentrations were related to decreased risk of prostate cancer.

They concluded greater pre-diagnostic serum selenium concentrations were not associated with prostate cancer risk in this large cohort, although greater concentrations were associated with reduced prostate cancer risks in men who reported a high intake of vitamin E, in multivitamin users and in smokers.