Aspirin May Not Prevent Colon Cancer, Study Finds

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A new study published in the Cochrane Database of Systematic Reviews looked at the potential benefits and harms of taking daily aspirin to prevent colorectal cancer in the general population. The researchers found that while aspirin may slightly reduce colorectal cancer incidence after 15 years of use, the evidence is of very low certainty. In contrast, the study found a definite and significant increase in the risk of serious bleeding in the stomach and brain with long-term aspirin use. The researchers conclude that for people not at high risk for colorectal cancer or cardiovascular disease, the potential risks of daily aspirin likely outweigh the uncertain benefits.

Why it matters

Colorectal cancer is a major public health concern, with rising rates in recent years. Some healthcare providers have prescribed daily aspirin to certain at-risk individuals in an attempt to lower their cancer risk. However, this new research suggests that for the general population, the potential downsides of long-term aspirin use may not justify its use as a preventative measure against colon cancer.

The details

The study analyzed data from 10 randomized controlled trials involving nearly 125,000 participants who took aspirin daily. Researchers looked at the incidence of colorectal cancer, colorectal cancer deaths, and serious side effects like brain bleeding and hemorrhagic stroke. They found that in healthy people, taking aspirin for 5-15 years made little to no difference in colorectal cancer incidence. After 15 years, aspirin may slightly reduce cancer incidence, but the evidence is very low-certainty. For colorectal cancer deaths, the researchers found that 5-10 years of aspirin use may actually increase mortality risk, while 10-15 years showed no difference, and 15+ years may reduce mortality, though again the evidence is low-certainty. The clear and high-certainty risk is an increased chance of serious bleeding in the stomach and brain with long-term aspirin use.

• The study analyzed data from randomized controlled trials spanning 5 to 15 years of aspirin use.
• After 15 years of aspirin use, the researchers found a potential slight reduction in colorectal cancer incidence, but the evidence was of very low certainty.

What they’re saying

What’s next

The researchers recommend that instead of relying on aspirin, the most effective way to prevent colorectal cancer is through regular screening tests like colonoscopies, which can detect and remove precancerous polyps before they develop into cancer.