Should I Take Aspirin to Prevent Cancer?

Aspirin is a non-steroidal anti-inflammatory drug (NSAID) that is commonly used to reduce fevers and relieve mild to moderate pain deriving from muscle aches or strains, toothaches, headaches, and symptoms of the common cold. 

Research so far suggests that taking a small dose of daily aspirin over a period of years can reduce the risk of certain cancers, but further study is needed. Currently the U.S. Preventive Services Task Force (USPSTF) does not recommend that people in the general population take aspirin to prevent cancer. 

For certain high-risk populations of people, however, the data supporting the benefits of regular aspirin use is clearer. For example, aspirin does benefit people with an inherited high risk of cancer due to Lynch syndrome and some people who have already had cancer and want to reduce the risk of it coming back. 

Regular aspirin use comes with risks, such as increased risks of bleeding and digestive tract issues including irritation and ulcers, particularly in people who have conditions that make bleeding or gastrointestinal concerns more likely. Please consult a physician before taking aspirin regularly. 

Should I take aspirin to prevent colon cancer? 

The U.S. Preventive Services Task Force (USPSTF) previously recommended some adults take regular low-dose aspirin for prevention of colorectal cancer, but the panel of experts removed that recommendation in 2022 based on results of one study in elderly adults that cast doubts on the benefits of preventive aspirin use.  

The task force will continue to review new evidence regarding the use of aspirin to prevent colorectal cancer. For people who are at higher risk of bleeding or gastrointestinal tract concerns, the potential benefit of preventing cancer is likely outweighed by the risk.  

For higher risk populations, however, there is evidence suggesting regular aspirin use could be beneficial. 

People with previous polyps  

Multiple studies link aspirin with a reduced risk of colorectal polyps, which are abnormal growths. For instance, this randomized trial showed that three years of daily aspirin can reduce the risk of new polyps in people with a history of polyps. Polyps don’t always develop into cancer, but they are generally considered to be pre-cancerous. 

People with Lynch syndrome 

Patients with Lynch syndrome are at an extremely high risk of developing colorectal, ovarian, prostate, and pancreatic cancer. The CaPP2 and CaPP3 studies found that daily low-dose aspirin taken over the course of a few years substantially reduces the risk of colon cancer in these patients and can reduce the risk of other cancers associated with Lynch syndrome. 

Should I take aspirin to reduce my risk of other forms of cancer? 

There are multiple observational studies looking at associations between aspirin use and the risk of ovarian and liver cancer. Below are several examples of large cohort studies led by Harvard researchers showing associations of decreased risk of colorectal, ovarian, and liver cancers. 

Ovarian cancer 

A 2018 observational study by Harvard scientists used data from the Nurses’ Health Study and Nurses’ Health Study II, finding that low-dose aspirin users have a 23% lower risk of developing ovarian cancer than with non-users. However, long-term, high-quantity non-aspirin NA-NSAID users were at a 19% higher risk of developing ovarian cancer than non-users. 

Liver cancer 

A 2018 study involving Dana-Farber’s Jeffrey A. Meyerhardt, MD, MPH, found that regular aspirin use was associated with a statistically significant reduction (49%) in hepatocellular carcinoma, the most common type of liver cancer, risk compared to non-regular or no use. They found that the risk reduction was dependent on both dose and duration; in this case, a minimum of 5 years of regular aspirin use and consumption of at least 1.5 or more standard dose tablets a week. 

More research is needed 

Ultimately, more observations and testing in interventional studies are needed to determine whether these findings are accurate and to solidify recommendations for the use of aspirin to prevent cancer in the general population. 

Should I take aspirin to prevent cancer recurrence? 

Some studies have suggested that patients with cancer who take aspirin or other NSAIDs may have a lower risk of cancer recurrence. These studies have led to change in clinical guidelines for treatment, particularly for colorectal cancer.  

Please consult your care team before initiating regular use of aspirin or other NSAIDs. 

Recommendations about aspirin use for cancer survivors is different from recommendations for the general population because these groups face different risks and benefits. 

Colorectal cancer recurrence 

The current guidelines from the National Comprehensive Cancer Network (NCCN) recommend aspirin be added to treatment after surgery for patients with colorectal cancer who have mutations in PIK3 pathway genes. Approximately 30 to 40% of patients with colon cancer harbor mutations in these genes. 

• In 2024, an analysis of data from a randomized clinical trial led by Meyerhardt for patients with stage III colon cancer suggested that patients with PIK3CA-mutated colon cancer could benefit from adding an NSAID called celecoxib to treatment with chemotherapy after surgery. 

• In 2025, results from a randomized study of people with colorectal cancer with mutations in PI3K pathway genes showed a benefit with 3 years of 160mg daily of aspirin. 

Prostate cancer recurrence 

A 2019 study found that regular aspirin use was associated with a lower risk of lethal prostate cancer. Patients who started taking aspirin after a prostate cancer diagnosis had an improved survival over those who did not begin regular aspirin use.  

Research is still ongoing, however, with some studies suggesting that aspirin does not have a benefit and other suggesting a dose and duration dependency. Consult with your physician before initiating regular aspirin use.  

Breast cancer recurrence 

A study published in 2024 and led by Dana-Farber’s Wendy Chen, MD, and Ann  Partridge, MD, looked at the use of daily aspirin to improve survival after treatment for non-metastatic breast cancer. The researchers found no benefit of aspirin on breast cancer recurrence and survival.  

Potential harms of aspirin 

Taking a daily dose of aspirin can be beneficial, but the benefits still need to be carefully weighed against the hazards with the help of a physician. 

Aspirin intake can result in an increased risk of bleeding, including a hemorrhagic stroke, which can be caused by a burst blood vessel. Aspirin can also cause problems with your digestive tract, including stomach lining erosion, irritation (gastritis), or ulcers. 

Some people prefer to substitute baby aspirin for regular strength aspirin to reduce the chance for potential side effects. In terms of cancer prevention, the data are a bit mixed as to whether a higher dose is better for deterring the development of certain cancers. 

If you are on a regular aspirin regimen, make sure you tell your surgeon or dentist if you need to have dental work or a surgical procedure. If you don’t, you may have excessive bleeding during these procedures. Those who consume aspirin and alcohol regularly may have an increased risk of stomach bleeding. Be sure to speak to your doctor about how much alcohol is safe to drink. 

About the Medical Reviewer

Dr. Meyerhardt received his MD from Yale School of Medicine in 1997. He completed a residency in internal medicine at Beth Israel Deaconness Medical Center, in Boston, followed by a medical oncology fellowship at DFCI. He joined the Gastrointestinal Cancer Center at DFCI in 2002..