Can Aspirin Help Reduce Your Cancer Risk?

Taking a low dose of daily aspirin is known to have some health benefits. For example, it can help reduce the risk of heart attacks and strokes for some people. In cancer, researchers are studying whether taking a daily aspirin can help prevent cancer and help keep it from coming back.

Many studies have found that some people who regularly take aspirin (acetylsalicylic acid or ASA) or other nonsteroidal anti-inflammatory drugs (NSAIDs) have a lower risk of developing colorectal cancer and polyps. Previous research has also suggested that taking aspirin may help prevent colorectal cancer from coming back. 

A new study looked at 626 people being treated for colorectal cancer who have a certain genetic mutation called PIK3CA. Patients were divided into 2 groups and were studied for 3 years. One group took a daily aspirin, while the other group took a placebo (a fake pill). Researchers found that the people taking a daily low dose of aspirin were 55% less likely to have their cancer come back than those who did not take daily aspirin.

The study findings were presented at the 2025 ASCO Gastrointestinal Cancers Symposium.

It’s important to remember that research on aspirin in cancer prevention is still ongoing. “The role of aspirin in helping to prevent cancer has been a major area of study over the years, though data from such research has sometimes been conflicting,” said Matthew B. Yurgelun, MD, FASCO, CGAF, an American Society of Clinical Oncology (ASCO) expert and medical oncologist at the Dana-Farber Cancer Institute.

Benefits vs. risks of taking aspirin

There are several reasons your doctor might recommend taking a low dose of aspirin every day. For example, a daily aspirin might be prescribed for people who are at a higher risk of having a heart attack or stroke. Aspirin can cause the blood to become thinner which makes it harder for blood clots to form.

For people who take a low-dose aspirin as prescribed to prevent heart problems, there may be an added benefit of reducing the risk of colorectal cancer.

But taking aspirin every day isn’t always safe. It can cause serious (and even life-threatening) problems in some people. If you’re thinking about starting a daily aspirin or other NSAID, it’s important to check with your doctor before taking any of them on a regular basis.

The possible dangerous effects of taking aspirin include:

• Increased risk of bleeding. This risk is higher for older adults and people taking other medications that might cause bleeding. These include NSAIDs like ibuprofen (Motrin or Advil) and naproxen (Aleve), and blood thinners like heparin or warfarin (Coumadin).
• Inflammation of the stomach and small intestine. This can lead to ulcers and bleeding. Drinking alcohol while taking daily aspirin may further increase the risk of stomach bleeding. 
• Allergic reaction. Some people may have an allergy to aspirin. Allergic reactions can be mild, but more severe reactions can potentially happen.

Here are some questions you might want to ask your doctor if you are considering taking a daily aspirin.

• What are the potential benefits of taking aspirin every day?
• What are the potential risks of doing so?
• Based on my health, would taking a daily aspirin be a good option for me?

Dr. Yurgelun is an Associate Editor on ASCO’s Patient Information Editorial Board.