A major Swedish-led trial has found that a daily low dose of aspirin can cut the risk of colorectal cancer returning by more than half in patients with specific genetic mutations.
Researchers tested more than 3,500 patients across Sweden, Norway, Denmark and Finland, identifying 1,103 with mutations in the PI3K pathway. Those given 160mg of aspirin daily after surgery were 55% less likely to see their cancer return within three years compared with patients on a placebo.
Lead researcher Prof Anna Martling of the Karolinska Institute called the results “a huge effect,” stressing the importance of genetic testing so eligible patients can benefit. Aspirin appears to work by reducing inflammation, disrupting the PI3K pathway and limiting blood platelets that shield tumour cells from the immune system.
While aspirin is cheap and widely available, long-term use carries risks, including bleeding and allergic reactions. Four severe adverse events were reported during the trial, with one possible aspirin-related fatality.
Experts say larger trials are needed, but the findings could change clinical practice and offer a simple, affordable tool to prevent colorectal cancer returning in high-risk groups.
