Aspirin makers rejoice. Not only is taking a low dose of aspirin (for many people) a preventive measure for heart attacks, it now appears it may have a similar preventive effect for some kinds of cancer. A major study led by Professor Peter Rothwell of Oxford University (UK) and published in the medical journal The Lancet [Effect of daily aspirin on long-term risk of death due to cancer: analysis of individual patient data from randomised trials] examined the results of several aspirin-use studies (mostly aimed at using aspirin for cardiac conditions) covering more than 25,000 people. The researchers found that a low-dose of aspirin (75 milligrams or less) taken daily for at least five years can reduce the fatal incidence of colorectal cancer and possibly other cancers of the digestive tract by a very significant 20-30%.
Assuming that this study passes critical muster (it’s certain to draw an enormous amount of attention from the medical community), there is still the big question: How does aspirin affect cancer? What, if any, are the causal links, the chemical pathways? It’s a little like having a massive amount of circumstantial evidence but no smoking gun.
It’s almost a sure thing that this news will cause a rise in un-monitored use of aspirin in unwarranted situations. Doctors are already emphasizing the warning that regular use of aspirin can cause serious internal bleeding (ulcers in particular), and that the decision to take a daily dose of aspirin should involve weighing the benefits of limited but useful prevention of cancer and heart attacks against the danger of bleeding and other possible complications.
Professor Tom Meade of the London School of Hygiene and Tropical Medicine, and one of the contributors to the study commented:
‘These are very exciting and potentially important findings. They are likely to alter clinical and public health advice about low dose aspirin because the balance between benefit and bleeding has probably been altered towards using it’, although Professor Meade adds that this does not mean everyone should automatically take aspirin. Health professionals and others will now have to consider the practical implications.