• Posted January 29, 2025

Daily Aspirin Reduces Colon Cancer Risk: Study

Daily low-dose aspirin can help prevent cancers from returning in about a third of colon cancer patients, a new study says.

Taking 160 milligrams of aspirin a day cuts the risk of cancer recurrence in half among colon cancer patients with a mutation in their PI3K genes, researchers reported at the 2025 American Society of Clinical Oncology Gastrointestinal Cancers Symposium in San Francisco.

These PI3K mutations are found in about 30% of all colon cancers, researchers said in background notes. They can make cancers more aggressive and harder to treat.

The results of this study could immediately change treatment for those colon cancer patients, researchers said.

“Aspirin has been shown to effectively reduce recurrence rates and improve disease-free survival in more than one-third of these patients,” lead researcher Dr. Anna Martling, a professor of surgery at the Karolinska Institute in Sweden, said in a news release.

For the study, researchers recruited more than 600 patients in Sweden, Denmark, Finland and Norway who had moderate to advanced colon cancer or rectal cancer.

The patients were randomly assigned to take either daily aspirin or a placebo for three years.

Patients taking daily aspirin had a 51% lower risk of cancer recurrence if they had a mutation in their PIK3CA mutation, compared to placebo, researchers found. Recurrence was 7.7% for people taking aspirin versus 14.1% for those on placebo.

Likewise, patients with other PI3K mutations had a 58% lower risk of cancer recurrence if they took aspirin -– 7.7% for those patients versus 16.8% for those given placebo tablets.

Overall, patients who took aspirin were 55% less likely to have their cancer recur than those on placebo, researchers said.

In addition, side effects related to aspirin use were rare, researchers said. There was one case of severe gastrointestinal (GI) bleeding, one case of brain bleeding and one allergic reaction.

“The old adage ‘take two aspirin and call me in the morning’ may now find a new meaning,” said Dr. Pamela Kunz, chief of GI medical oncology at the Yale School of Medicine, who was not involved in the study. 

“A simple intervention of low-dose aspirin reduces the risk of colorectal cancer recurrence for patients with genetic changes in the PI3K signaling pathway, occurring in one-third of patients with colorectal cancer,” Kunz added in a news release.

Findings presented at medical meetings should be considered preliminary until published in a peer-reviewed journal. The conference took place Jan. 23-25.

More information

The American Cancer Society has more about colon cancer.

SOURCE: American Society of Clinical Oncology, news release, Jan. 25, 2025