Around 29 million people in the US take a daily dose of aspirin as a preventative measure for cardiovascular disease. And while an age-related increased risk of bleeding has seen it fall out of favor with medical authorities, it's now shaping up as something that might be even more beneficial in triggering the immune system to help take down certain cancers.

There's been a growing body of research showing that regular, long-term low-dose aspirin use was associated with better outcomes of colorectal cancer (CRC). But scientists haven't been entirely sure just why the common over-the-counter medicine was having a distinctive and seemingly targeted effect on the growth and spread of CRC, and gathering long-term data on this area of aspirin use has been challenging.

That earlier Harvard-led study found that a regular aspirin regimen could prevent almost 11% of colorectal cancers and 8% of gastrointestinal cancers diagnosed in the US every year. Now, Italian researchers have looked at clinical and pathological records of all CRC patients operated on at Chirurgia Generale Unit in Padova, Italy, from 2015 to 2019. Of these 238 patients, 31 (13%) were considered aspirin users – those who took 100 mg of the nonsteroidal anti-inflammatory drug per day.