High-Dose Aspirin Prevents Colon Cancer
But Risk Outweighs Benefit Seen With High-Dose, Long-Term Use
Aug. 23, 2005 -- Aspirin and ibuprofen can prevent colon cancer. But don't try this at home.
The common painkillers, a new study shows, only cut cancer risk when taken at high doses for more than 10 years. At those doses, the risk from taking the drugs outweighs the cancer-prevention benefit.
Andrew T. Chan, MD, MPH, of Massachusetts General Hospital, and colleagues report the findings in the Aug. 24/31 issue of The Journal of the American Medical Association.
"This is an exciting advance because it does suggest we can, down the road, develop cancer-preventing medicines," Chan tells WebMD. "We cannot at this point recommend aspirin as a preventive therapy for most people."
That's a pretty strong warning not to try this at home. But Eric J. Jacobs, PhD, senior epidemiologist for the American Cancer Society, makes it even clearer.
"Aspirin can cause very serious side effects, including potentially fatal gastrointestinal bleeding," Jacobs tells WebMD. "Use of aspirin at any dose to prevent cancer is not recommended by the American Cancer Society or by any other group."
Lots of Nurses, Lots of Aspirin and Ibuprofen
Earlier this year, a study showed that low-dose aspirin taken every other day has
in women. But previous, smaller studies showed that aspirin and NSAIDs -- the ibuprofen family of over-the-counter painkillers -- can have anticancer effects.
Might aspirin and NSAIDs prevent cancer if taken at high doses for a long time? To answer this question, Chan's team looked at data from the Nurses Health Study. Since 1980, this study has gathered 20 years of data on nearly 83,000 women.
Significant Cancer-Fighting Effects
The researches found that only high doses of aspirin or NSAIDs -- taken for at least 10 years -- have significant anticancer effects.
Nurses who took 14 regular-strength aspirin tablets every week for more than 10 years cut their colon cancer risk by 53%. Those who took more than 14 ibuprofen or other NSAID pills every week for 10 years cut their colon cancer risk by 54%.
But taking all those painkillers came at a cost. The women who took such high doses of aspirin, for example, upped their chances of life-threatening stomach or intestinal bleeding by 57%.
"The trade-off needs to be looked at more closely. But it would appear that if you treated 10,000 women with high-dose aspirin for over a year, you would prevent one or two cases of colorectal cancer at the expense of causing eight cases of gastrointestinal bleeding," Chan says.
The Drug-Free Way to Beat Colon Cancer
If you want to prevent colon cancer, you don't have to take a lot of aspirin. In fact, you don't have to take anything.
All you have to do is start getting colon cancer screening tests. Most people don't have to do this until they turn 50. However, people at particularly high risk of colon cancer should start earlier. This group includes people whose parent, sibling, or child has colon or rectal cancer or polyps; people with a family history of hereditary colon cancer syndromes; people who have had colon cancer or polyps; and people who have had chronic inflammatory bowel disease.
The American Cancer society recommends five forms of colon cancer screening. The first three generally are considered most effective:
- Get a colonoscopy every 10 years.
- Get a double contrast barium enema every five years.
- Get a yearly stool blood test and a flexible sigmoidoscopy every five years (this is preferred over the following two options).
- Get a flexible sigmoidoscopy every five years.
- Get a yearly stool blood test (FOBT) or fecal immunochemical test (FIT).