Chemoprevention and Colorectal Cancer

Are there ways to prevent colorectal cancer? Good epidemiologic evidence would suggest that there is. While dietary fiber probably does not play a role, several other factors may.

SELENIUM:

In a prospective, randomized trial of selenium for skin cancer, the investigators found that 200 micrograms of selenium was not associated with any changes in skin cancer, but a 60% REDUCTION IN COLORECTAL CANCER! They also found a 50% reduction in all cancer deaths amongst those on selenium supplements. A much larger trial over a 12-year period is scheduled to be completed in 2013.

CALCIUM:

Patients taking 3.0 grams of calcium carbonate per day were found to have a 36% reduction in advanced pre-cancerous lesions (adenomas) of the colon during their 4-year study. A second study using 2.0 grams/day for 3 years found a similar reduction. The Women's Health Initiative is a much larger trial which is examining the effect of calcium and colon cancer risk and should be completed around 2010.

ASPIRIN:

Two trials recently published in the New England Journal of Medicine demonstrated the effect of aspirin on reducing the risk of advanced pre-cancerous lesions (adenomas) in the colon. Aspirin use (81 mg/day) over an approximately 3-year period was associated with up to a 42% reduction in advanced adenomas.