Cancer fears: what science says about aspirin’s potential benefits

For decades, aspirin has been a common medicine for pain relief, inflammation, and heart health.

Now, emerging research suggests aspirin may also play a role in reducing cancer spread in certain patients.

That possibility is drawing attention, but experts warn that the evidence is still developing, and the risks are real.

How aspirin may affect cancer spread

Professor Anna-Mart Engelbrecht says aspirin appears to interfere with how cancer cells move through the body.

She explains that platelets, blood cells responsible for clotting, can help cancer cells travel in the bloodstream and spread to other organs.

Aspirin blocks this platelet activity.

That may reduce the risk of metastasis, the process by which cancer spreads, and the main cause of cancer-related deaths.

Evidence strongest in specific cancer group

The most significant findings so far are linked to people with Lynch syndrome.

This is an inherited condition that increases the risk of cancers, especially colorectal and endometrial cancer.

In one clinical trial involving 861 patients with this genetic risk, participants took 600mg of aspirin daily for more than two years.

The result: a 50% reduction in colorectal cancer risk after long-term follow-up.

Researchers describe this as a “remarkable” reduction, but stress it applies specifically to this high-risk group.

Genetic testing key for some patients

Most people do not know if they have Lynch syndrome.

It requires genetic testing.

Experts say those with a family history of colorectal cancer may consider testing to better understand their risk.

But aspirin is not a one-size-fits-all cancer prevention strategy.

Ongoing global trials

Larger international trials are now underway, involving around 11,000 participants.

These studies are looking at aspirin’s effects across multiple cancers, including breast and prostate cancer.

Researchers are also trying to balance potential benefits with known risks, especially bleeding.

Serious risks cannot be ignored

Aspirin reduces blood clotting, which increases bleeding risk.

This is a major concern, particularly for cancer patients who may already be vulnerable.

High daily doses, such as 600mg used in trials, are considered significant.

Professor Engelbrecht warns that patients in studies are closely monitored.

She is clear: people should not start taking aspirin for cancer prevention without medical advice.

Other common drugs under investigation

Researchers are also exploring whether other widely used medicines could help fight cancer.

One example is metformin, a common diabetes drug.

Early observations suggest some patients on metformin respond better to cancer treatment.

This approach, known as drug repurposing, is gaining attention globally.

What it means for people worried about cancer

The research offers cautious hope.

Aspirin may reduce cancer spread in certain cases, especially in genetically high-risk groups.

But the evidence is not universal.

And the risks, particularly bleeding, are significant.

The message from experts is clear: do not self-medicate.

Any use of aspirin for cancer prevention should be guided by a doctor, based on individual risk and medical history.