Selenium Supplementation may Reduce Colorectal Cancer, Particularly in Smokers.

A study conducted at a number of university medical centers, coordinated by the National Cancer Institute (NCI) and published in the Cancer Epidemiology, Biomarkers and Prevention (15, 2:315-20, 2006) investigated the potential interaction of smoking and serum selenium levels in advanced colorectal cancer. They found that higher serum levels of selenium may reduce the risk of advanced colorectal cancer, particularly in recent smokers.

Researchers studied the association between serum selenium and advanced colorectal adenoma in 758 cases and 767 sex- and race-matched controls, randomly selected from the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial. Cases had at least one verified advanced adenoma of the distal colon, while controls had a negative sigmoidoscopy. While there was a significant inverse association between serum selenium and advanced colorectal adenoma among recent smokers, there was no relationship between serum selenium and adenoma risk in nonsmokers and former smokers who quit smoking more than 10 years before. The study concluded selenium may reduce the risk of developing advanced colorectal adenoma, particularly in the high-risk group of recent smokers.