Still, aspirin does raise a person's risk of bleeding and it's possible that
this risk, especially at high doses, outweighs the anti-cancer benefits,
according to a related editorial.
The results, which are published in the Annals of Internal Medicine, are
based on a study of more than 27,000 women who underwent colonoscopy between
1980 and 1998.
At enrollment, the participants reported no history of colon tumors or other
diseases. Aspirin use was assessed with biennial questionnaires.
During the study period, 1368 cases of colon cancer were diagnosed, lead
author Dr. Andrew T. Chan, from Massachusetts General Hospital in Boston, and
colleagues note.
Overall, women who used at least two standard aspirin tablets per week were
25 percent less likely to develop a tumor than were less frequent users.
Moreover, the tumor risk fell as aspirin use increased. Compared with non-use,
the use of more than 14 tablets per week decreased the risk by 51 percent. This
association held true for both short- (no more than 5 years) and long-term
aspirin users.
"Before aspirin can be recommended for chemoprevention in the general adult
population, these results suggest the need for a more thorough evaluation of the
risks and benefits of routine aspirin use at doses not previously considered,"
the authors state.
In a related editorial, Dr. Robert S. Sandler, from the University of North
Carolina in Chapel Hill, warns that "until we have different or better
information from randomized trials, aspirin use should be limited to persons at
higher risk for (tumors)" and to persons without diseases for which aspirin use
might be hazardous.
SOURCE: Annals of Internal Medicine, January 2004.
