A tried and trusted remedy for pain, fever and inflammation since the 19th Century, aspirin is gaining a modern day reputation for the prevention and treatment of cardiovascular disease and some cancers including bowel cancer.
While not quite a miracle drug - aspirin can cause serious side effects such as gastrointestinal bleeding - its effectiveness, versatility and low cost suggest it will remain one of the most widely used medications.
Aspirin is already recommended for secondary prevention of heart attacks and strokes in people with a history of these conditions.
For the bowel cancer community, aspirin also offers the hope of preventing new cancers and improving the prognosis for those already diagnosed.
National Health and Medical Research Council (NHMRC) Guidelines[i] support the use of low dose aspirin to prevent the development of new adenomas (bowel polyps) in people with a history of prior adenomas.
The recommendations are based on the findings of a growing number of studies in Australia and overseas. Collectively the evidence suggests aspirin can lead to a reduction of bowel cancer risk by about 40 per cent.
However more research is needed to establish an optimal dose and duration of use.
While aspirin is recommended for people at a higher risk of bowel cancer due to their personal or family history of bowel cancer, there is no similar recommendation for people at average risk of bowel cancer.
For many people, the risks of prolonged aspirin use may still outweigh the benefits. For example, while bowel cancer risk increases with age, so too does the potential for adverse effects from medications and interactions between medications in older people.
Aspirin may be of more use as an additional treatment for bowel cancer. It has been shown to increase survival in people already diagnosed with bowel cancer.[ii]
A recent study found a daily dose of aspirin taken for nine months after a bowel cancer diagnosis, reduced the risk of dying by 30 per cent.
Several mechanisms have been suggested to explain the anti-cancer effect of aspirin. Aspirin may:
- inhibit cell proliferation
- increase programmed cell death
- inhibit the growth of new blood vessels that support cancer growth, or
- enhance the immune system.