A new Swedish trial shows that taking a low daily dose of aspirin after surgery can halve the risk of colorectal cancer returning in patients with certain genetic mutations.
Researchers at the Karolinska Institute tested more than 3,500 patients who had colorectal tumours removed across Sweden, Norway, Denmark, and Finland. Genetic analysis revealed that 37% had mutations in the PI3K pathway, which makes tumours more responsive to aspirin’s effects. Patients taking 160mg of aspirin daily for three years were 55% less likely to experience a recurrence compared with those on a placebo.
Aspirin appears to work by reducing inflammation, interfering with the PI3K pathway, and limiting platelet activity, which can protect tumour cells from the immune system.
Prof Anna Martling, who led the trial, emphasized the importance of genetic testing for colorectal cancer patients to identify those who could benefit. “It’s a widely available drug that is extremely inexpensive,” she said.
However, aspirin is not without risks. In the trial, a few patients experienced severe side effects, including gastrointestinal bleeding, allergic reactions, and one possible aspirin-related death.
Experts say these findings could transform clinical practice by offering an inexpensive, effective way to prevent cancer recurrence in genetically susceptible patients. Further large-scale studies are needed to confirm the long-term benefits and safety.
