I just had a very good question after I published my list of Twelve Tips to Reduce Your Risk of Colorectal Cancer.
Dear Dr. Petty,
“That’s a great list, but I am wondering why you haven’t included aspirin or other non-steroidal anti-inflammatory drugs (NSAIDs)? I thought that they had been shown to reduce the risk of colon cancer.”
This is an excellent question, and I deliberately omitted mention of anti-inflammatories because the research suggests that they may cause more harm than good.
There is a report in today’s edition of the Annals of Internal Medicine from the United States Preventive Services Task Force, a highly regarded and independent panel of experts in primary care and prevention, that confirms that screening for colorectal cancer is still important and everyone over 50 should have it. But they urge caution on taking preventive drugs, saying that on balance the health risks of aspirin outweigh the benefits when it comes to preventing colon cancer. This advice holds even for those people with a family history of the disease, as long as they have only an average risk of colon cancer. (20 per cent of people who get colorectal cancer also have a close relative with the disease, with proportionally more cases among African Americans than other races.)
They found good evidence that high doses of aspirin (i.e. 300 mg a day or more) and possibly ibuprofen protect against colorectal cancer but this comes with increased risk of intestinal bleeding, stroke and kidney failure.
In low doses - under 100 mg a day - the Task Force says that good evidence supports the notion that aspirin protects against heart disease. However, at this dosage it will have no preventive effect on colorectal cancer.
The US Preventive Services Task Force regularly reviews the available research evidence and issues advice based on what they regard the strength of the evidence to be. They use a grades to help guide practice. For example a grade A recommendation is equal to "strongly recommends", while a B is just "recommends", and C is "no recommendation for or against".
In this case the Task Force has issued a grade D "recommends against" to the routine use of aspirin and NSAIDs to prevent colorectal cancer.
So for now I recommend following the Twelve Tips that I published yesterday.
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