The possibility of using aspirin to prevent cancer was a 'serendipitous finding'. Aspirin has long been regarded as a drug which prevents and helps treat strokes and heart attacks. The findings about aspirin helping protect patients against cancer were a byproduct of studies which were primarily designed to further define the role of aspirin in patients with strokes and heart attacks.
This kind of chance discovery, known as serendipitous finding, is common in biomedical research. Indeed penicillin too was discovered serendipitously. Serendipitous is derived from Serendip, the old Sanskrit name for Sri Lanka. In an 18th century play by Horace Walpole called The Three Princes of Serendip, the princes made remarkable discoveries that they were not seeking during their travel to Sri Lanka. Hence serendipity came to mean a chance discovery.
Results of a large meta-analysis (pooled studies of 25, 570 people who either took aspirin or a placebo) revealed that the aspirin group had 21 per cent less chance of dying of cancer when compared to the placebo cohort. The longer the duration of aspirin therapy, the greater the benefits. Pancreatic, brain, lung, stomach and prostate cancer were some of the cancers that were prevented. Peter Rothwell and colleagues at the John Radcliffe Hospital in Oxford carried out the study which was recently published in a major medical journal. However, further research and consensus among the scientific community are required to determine whether people should definitely take aspirin to prevent cancer. In addition, bleeding ulcers in the stomach, a clear life-threatening side-effect of aspirin, needs to be factored in and the risk-benefit ratio has to be calculated.
In the meantime, however, this same group headed by Peter Rothwell recently made another remarkable, less-known discovery. They published data which showed aspirin could be useful in the treatment (not just prevention) of cancer. They found aspirin reduced the risk of spread (metastasis) of cancer (for example, adenocarcinoma) by almost half in patients who remained on aspirin following their diagnosis. Indeed high-risk patients already taking aspirin for the prevention of cardiovascular diseases, a method commonly prescribed even in Nepal, should welcome the findings from these recent large scale- studies. However, it may be counterproductive to start in taking aspirin on your own without consulting a doctor.