In women, aspirin could reduce the risk of developing colon cancer by 20 percent, suggests research.
For the study, researchers looked at 39,876 women in the age group of 45 and older.
For the study, participants took a 100 mg dose pill of aspirin or a placebo every other day from when they were enrolled in the study until 2004.
The participants also completed questionnaires about their cancer status, how often they took their medication, any negative effects, any additional aspirin use and other risk factors.
After the study, researchers followed 33,682 participants, who were not given additional aspirin or placebos for this additional time frame, through March 2012.
After nearly two decades, women in the aspirin group had a 20 percent less chance of developing colon cancer than those who were taking placebos.
And women who continued taking aspirin after the end of the trial had the lowest colon cancer risk, CBS News reported.
The study is set to appear in the Annals of Internal Medicine.