A US Task Force that regularly gives out advice based on reviews of research says 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, they say.
Writing in the March 6th edition of the Annals of Internal Medicine, the US Preventive Services Task Force, a highly regarded and independent panel of experts in primary care and prevention, confirms that screening for colorectal cancer is still important and everyone over 50 should have it, but they urge caution on taking preventive drugs.
They found good evidence that high doses of aspirin (ie 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.
"Individuals taking high doses of aspirin or NSAIDs (non-steroidal anti-inflammatory drugs) to prevent colorectal cancer should be aware of the potential harms and discuss them with their clinician," said Dr Ned Calonge, head of the Task Force and Chief Medical Officer and State Epidemiologist for Colorado.
People who take low doses to protect against other diseases such as those of the heart, should talk to their doctor about the benefits and risks, he added. It's probably OK for them to continue to do so, but they should still check with their doctor.
In low doses, that is under 100 mg a day, the Task Force says good evidence supports the notion that aspirin protects against heart disease. However, at this dosage it will have no preventive effect on colorectal cancer, they said.
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. 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.
Colorectal cancer is the third most common cancer for men and women in the US. And it comes second only to lung cancer as a leading cause of cancer-related deaths in America.
Approximately 56,000 Americans die from colorectal cancer every year, and 150,000 new cases are discovered. This equates to just under 6 per cent of the population developing the disease in their lifetime, with most cases occuring in the over 50s.
20 per cent of people who get colorectal cancer also have a blood relative with the disease, with proportionally more cases among African Americans than other races.
Click here for Annals of Internal Medicine.
Click here for more information about colorectal cancer (American Cancer Society).
Written by: Catharine Paddock
Writer: Medical News Today
Publication Date: 2007-03-06 12:00