Researchers at the University of Oxford found a link between high-dose aspirin users and a lower colon-cancer risk. But because long-term, high-dose aspirin usage can have adverse bleeding effects, the team also reviewed five trials involving 16,488 participants taking lower doses.
Nearly 20 years of follow-up showed that people assigned to low-dose aspirin regimens for six years were at one-quarter lower risk of colon cancer. Moreover, they were one-third less likely to die from the disease.
Longer periods of low-dose aspirin (75 milligram) use produced the same results as larger doses: a 70% reduced risk of colon cancer as well as lower rates of rectal cancer.
The study is particularly encouraging because the reduction in tumors was limited to the proximal colon, the portion farthest from the rectum. Researcher Peter M. Rothwell, MD, PhD, and colleagues commented, “The suggestion of a particular effect of aspirin on more aggressive and rapidly growing tumors might allow less frequent screening.”
More significantly, they also observed that “. . . the prevention of proximal colonic cancers by aspirin, which would not be identified by sigmoidoscopy screening and for which colonoscopy screening is only partly effective, is clearly important.”
Sources: Tufts University Health & Nutrition Letter, March 18, 2013 Study published in The Lancet