In a recent clinical trial, a low dose of aspirin reduced the risk of colon and rectal cancer recurrence by half in patients whose tumors carried a specific genetic mutation.
Just 160 milligrams of aspirin daily—about half a pill of a standard adult tablet—reduced cancer recurrence by around 60 percent in a certain patient subgroup.
These patients carried mutations in the PI3K gene, which affects about a third of all colorectal cancer patients.
“Aspirin is a drug that is readily available globally and extremely inexpensive compared to many modern cancer drugs, which is very positive,” lead study author Dr. Anna Martling, a professor at the Karolinska Institutet in Stockholm, Sweden, said in a statement.
Randomized Controlled Trial
The study, recently published in the New England Journal of Medicine, followed more than 600 colorectal cancer patients with a genetic change in the PI3K pathway from 33 hospitals across Sweden, Denmark, Finland, and Norway.
The findings showed that patients who took aspirin were less likely to see their cancer grow or come back over three years compared to those who took a placebo.
All participants had undergone surgery for stage 2 or stage 3 colon or rectal cancer. Patients were randomly assigned to take either 160 milligrams of aspirin or a placebo daily for three years. The study did not include colorectal cancer patients who did not carry the PI3K gene mutation.
Depending on where the gene mutation in the PI3K gene occurred, benefits from aspirin supplementation differed.
In the group with the PI3K mutation in exon 9 or 20, the risk of cancer returning was cut by 51 percent. For patients with PI3K gene mutations in other sections of the gene, aspirin reduced the recurrence risk by 58 percent.
Overall, patients who took aspirin were about 55 percent less likely to have their cancer return—less than half the recurrence rate seen in the placebo group.
The treatment could help more than one-third of colorectal cancer patients—a significant portion of the more than 100,000 Americans diagnosed with the disease annually, Martling said.
The exact mechanism by which aspirin reduces cancer recurrence in these patients is still unknown; however, one potential reason is that aspirin affects tumor-driving pathways involving PI3K.
Aspirin blocks a tumor-promoting protein called COX-2 while PI3K raises COX-2 levels. In patients with mutations in this pathway, aspirin can provide targeted inhibition of processes that encourage cancer.
Other parallel mechanisms include aspirin’s ability to reduce inflammation and inhibit platelet function, both of which drive tumor growth.
Treatment Guidelines Already Changing
The researchers say the study findings could change how doctors treat many colorectal cancer patients right away.
The study has already “changed our guidelines [at our cancer center] to indicate genetic testing for this mutation in a population we previously weren’t doing genetic testing on,” Dr. David Bajor, assistant professor of medicine and member at Case Comprehensive Cancer Center, and not involved in the study, told The Epoch Times.
He explained that previously, doctors had only tested patients with stage 4 disease for PIK3CA mutations, but now it is recommended to test patients with stages 2 and 3 as well.
“This research highlights the importance of precision medicine and the use of advanced diagnostics,” Martling said. “These tools can enable tailored treatments and the repurposing of existing drugs for new applications.”
Safety Profile and Risks
The findings indicate that side effects from daily low-dose aspirin were rare; however, there was one case each of severe gastrointestinal bleeding, brain bleeding, and an allergic reaction in the study groups.
Dr. Jason Korenblit, a board-certified specialist in gastroenterology and hepatology and an expert on JustAnswer, who was not involved in the study, said that even low-dose aspirin has risks. These include gastrointestinal bleeding, peptic ulcers, hemorrhagic stroke, as well as the risk of adverse interactions with other medications.
“Patients with a history of ulcers, bleeding disorders, anticoagulant use, or those at high risk for bleeding,” such as older people and those with kidney disease, “are at greater risk,” he said, adding that aspirin can irritate the stomach lining. “Those with concurrent NSAID [non-steroidal anti-inflammatory drugs] use, H. pylori infection, or other risk factors may [also] have higher risk.”
Researchers plan to continue analyzing the data, including looking at how factors such as gender and socioeconomic status might influence the outcomes.
Dr. Raj Dasgupta, a board-certified physician specializing in pulmonary, critical care, and sleep medicine, and not involved in the study, warned against cancer patients self-medicating with aspirin.
“The benefit showed up mostly in patients whose tumors had specific PI3K pathway mutations,” he said. “Which means it won’t necessarily help everyone the same way.”
For that reason, Dasgupta added, he wouldn’t recommend self-medicating.
“If someone is interested, the best step is to bring it up with their oncologist, who can look at their genetic profile and overall health to see if aspirin even makes sense.”
