Taking a daily low-dose aspirin pill can significantly reduce the risk of colorectal cancer returning in people with specific genetic mutations, a new study suggests.
The study followed nearly 3,000 colorectal cancer survivors in Sweden. About one-third had tumors with a specific genetic mutation in what’s called the PIK3 pathway. Researchers randomly assigned participants to take a 160 milligram daily aspirin pill or a placebo for three years after surgery to remove their tumors.
Participants with this genetic mutation who took daily aspirin were roughly half as likely to experience cancer recurrence by the end of the study period compared with those given a placebo, according to findings published in The New England Journal of Medicine.
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“Aspirin is being tested here in a completely new context: as a precision medicine treatment,” lead study author Anna Martling, MD, PhD, a professor of molecular medicine and surgery at the Karolinska Institute in Stockholm, said in a statement.
She went on to call the findings “a clear example of how we can use genetic information to personalize treatment and at the same time save both resources and suffering.”
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How Many Colorectal Cancer Survivors Could Benefit From Aspirin?
Whether aspirin can provide a protective benefit for certain colorectal cancer survivors may depend at least in part on how advanced the cancer is at the time of diagnosis.
The study focused on people with early-stage tumors contained in the colon or rectum (stage 1 cancer) or that had spread to nearby lymph nodes (stage 2 or 3) but not to distant organs (stage 4).
To know if a survivor might benefit from aspirin therapy would require genetic testing to see if they have the mutation, at a cost of about $1,000. This testing isn’t currently routine, says Richard Goldberg, MD, professor emeritus and director emeritus of the West Virginia University Cancer Center in Morgantown, but he believes it should become standard based on the new study results.
“My estimate is that as many as 5,000 U.S. lives could be saved annually by testing stage 1–3 patients for PI3K mutations and treating that subset of newly diagnosed patients starting at recovery from surgery,” says Dr. Goldberg, who coauthored an editorial in The New England Journal of Medicine accompanying the study.
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Annually, roughly 150,000 people receive a colorectal cancer diagnosis in the United States, and about 50,000 die from these malignancies, Goldberg says.
How Might Aspirin Prevent Cancer?
There are two possible ways that aspirin might help prevent cancer recurrence, according to the study authors: first, by reducing inflammation that fuels tumor growth, and second, by interfering with the formation of platelets in the blood that can protect tumors from immune system attacks.
It’s possible that daily low-dose aspirin could prevent colorectal cancer in people who have never had this disease. But potential side effects of aspirin therapy mean this strategy might not be as worthwhile for the general public as it is for certain cancer survivors trying to prevent recurrence, says Jeffrey Meyerhardt, MD, MPH, co-director of Colon and Rectal Cancer Center at the Dana-Farber Cancer Institute in Boston.
“On the prevention front, the risks of aspirin — including ulcers, bleeding, and allergic reaction — must be weighed against the possible benefits,” says Dr. Meyerhardt, referring to people who have never had cancer.
But the new study adds to the evidence suggesting aspirin therapy may still make sense for a lot of cancer survivors, says Meyerhardt, who coauthored the editorial with Goldberg.
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“Data consistently show aspirin to be beneficial for patients with tumors that have alterations in PIK3 pathways, so patients should discuss with their oncologist to have their tumor tested for such mutations,” Meyerhardt says.
