Daily Aspirin May Reduce Risk of Colorectal Cancer
But risks rule it out as population-wide chemopreventive drug
FRIDAY, May 11 (HealthDay News) -- Taking at least 300 mg/day of aspirin for five years confers protection against colorectal cancer, but the risks of taking the drug outweigh the benefits in the population as a whole, according to a report published in the May 12 issue of The Lancet.
Enrico Flossmann, D.Phil., and Peter M. Rothwell, F.R.C.P., of Radcliffe Infirmary in Oxford, U.K., analyzed data from two large randomized trials with more than 20 years of follow-up. The first trial comprised 5,139 subjects, of whom two-thirds took 500 mg/day of aspirin for five years while the remaining third were control subjects. The second trial comprised 2,449 subjects, two-thirds of whom took 300 mg/day or 1,200 mg/day of aspirin for one to seven years, and one-third of whom took placebo.
While subjects in the aspirin groups had lower incidence of colorectal cancer in both trials, the effects were only observable after 10 years and was greatest 10 to 14 years after the trials began.
However, the risks outweigh the benefits for the general population. "With the concerns about the potential risks of long-term aspirin use and the availability of alternative prevention strategies (e.g., screening), these findings are not sufficient to warrant a recommendation for the general population to use aspirin for cancer prevention," writes Andrew Chan, M.D., of Massachusetts General Hospital in Boston, in an editorial.
Rothwell has received honoraria from several pharmaceutical companies but none in support of this work.