Major cochrane review finds daily aspirin unreliable for bowel cancer prevention in average risk individuals

A major review of 124,000 people shows daily aspirin does not reliably prevent bowel cancer and carries immediate risks of serious internal bleeding.

By: AXL Media

Published: Mar 5, 2026, 3:25 AM EST

Source: The information in this article was sourced from Cochrane

Reevaluating the Role of NSAIDs in Oncology

For years, the medical community has debated whether common nonsteroidal anti-inflammatory drugs, or NSAIDs, could serve as a low cost preventative measure against colorectal cancer. This disease remains one of the most prevalent forms of cancer globally, typically managed through lifestyle modifications and regular diagnostic screenings. However, a new systematic review conducted by researchers at West China Hospital of Sichuan University has cast significant doubt on the efficacy of aspirin as a universal preventative tool. By analyzing data from 10 randomized controlled trials, the team sought to determine if routine aspirin use could effectively block the development of cancerous or precancerous growths in people at average risk.

Weak Evidence for Long Term Protection

The findings of the review suggest that for most individuals, aspirin offers no measurable reduction in bowel cancer risk during the first five to fifteen years of consistent use. Although some long term observational data hinted at a possible protective benefit after the fifteen year mark, the researchers labeled the confidence in this evidence as very low. These delayed effects are difficult to verify because participants in long term studies often change their medication habits or begin other treatments after the initial trials conclude. Consequently, the researchers found no high quality evidence to support the claim that aspirin serves as a reliable guard against the disease in the short or medium term.

Immediate Risks of Internal Hemorrhage

While the potential benefits of aspirin are slow to emerge and remain uncertain, the physical risks associated with the drug are immediate and well documented. The study found strong evidence that daily aspirin consumption significantly increases the risk of serious extracranial hemorrhage, which refers to bleeding outside the skull, such as in the gastrointestinal tract. Furthermore, regular use was linked to a higher likelihood of hemorrhagic stroke. Lead author Dr. Zhaolun Cai emphasized that these complications do not wait for years to develop, they represent an acute danger that begins as soon as the patient starts the regimen.