A study from Denmark found that taking one or two baby aspirins a day for at least five years was tied to a lower risk of colorectal cancer.
Earlier studies suggested that aspirin and non-steroidal anti-inflammatory drugs such as ibuprofen may help protect against colorectal cancer. However, it wasn’t clear how much had to be taken and for how long, to achieve those benefits.
Researchers used data from more than 113,000 individuals to sort out the relationship between aspirin and NSAIDs, duration of treatment and colorectal cancer rates.
According to the National Cancer Institute, the risk of developing colorectal cancer varies with age, race, ethnicity and lifestyle. More than 90% of cases are diagnosed in people older than 50.
The Centers for Disease Control and Prevention has an online risk calculator which indicates that in the U.S. for an average white or black woman in her late fifties. The 10-year risk of developing colorectal cancer is between 1 and 1.4 percent and her lifetime risk is between 5 and 5.4%. For an average black or white male of the same age, the corresponding risks would be about 1.4% and 5.8%.
The study found that taking low-dose aspirin continuously for at least five years appeared to reduce the risk of colorectal cancer by 27% and using non-aspirin NSAIDs for at least five years appeared to reduce it by 30%.
However, in contrast, merely having taken aspirin did not alter the colorectal cancer risk.
Unfortunately, aspirin and NSAIDs carry their own risks. Long-term use can cause gastrointestinal bleeding. Therefore, the potential reduction in colon cancer risk needs to be balanced against potential side effects.
The study had several limitations. Researchers only had data for users who obtained their aspirin or NSAIDs from doctors’ prescriptions. They didn’t include patients who made over-the –counter purchases of the medicines. Additionally, researchers are unable to rule out the possibility that other factors may have increased participants’ risk for colorectal cancer, such as obesity, dietary habits, alcohol use, and family history of colorectal cancer.
Researchers discourage self-medication with aspirin or non-aspirin NSAIDs due to the possibility of serious adverse events. The public should not take any medication regularly without consulting with a physician.