Download Patient information – aspirin and cancer

Aspirin and cancer patient information leaflet 2012
What is aspirin?
Aspirin (acetylsalicylic acid) has been used for many years as a painkiller. It has an antiinflammatory action, and is used to relieve headache, menstrual pain and muscle aches.
More recently it has been given to patients with known cardiovascular disease risk factors to
reduce their chance of stroke and heart attack.
What effect does it have on cancer?
Taking a small daily dose of aspirin has been linked to a reduced risk of cancer. A number of
studies have suggested aspirin may protect against cancer. Latest work in The Lancet that
looks at 51 studies involving over 77,000 participants suggests aspirin not only reduces a
person's risk of developing cancer but could also help stop cancers spreading around the
body. Cancer death rates were also significantly lower among people taking aspirin.
How long do you need to take aspirin to see this benefit?
The Lancet study showed that the effect of aspirin on cancer increases with time. For the
first 3 years of following patients up aspirin has no effect. However beyond 3 years of followup a consistent decrease in cancer incidence is shown, averaging about 25% less cases in
patients taking aspirin.
How does it work?
For cardiovascular disease it works by helping to prevent blood clots forming in the blood
vessels, by stopping cells in the blood known as platelets from sticking together and clogging
an artery. Aspirin’s effects on cancer cell growth and spread is much less well understood.
Why low-dose aspirin?
UK experts recommend 75mg for heart disease prevention. This is a lot less than the dose
for pain relief. This is because taking aspirin every day raises the risk of side effects like
internal bleeds.
What are the risks?
Low-dose aspirin treatment is linked with a very small increase in the risk major bleeding in
the stomach and brain. Studies suggest that 769 people would need to be treated with lowdose aspirin for one extra person to be harmed with major bleeding.
Who should take it daily?
Anyone considering taking aspirin is advised to talk to their doctor first.
In the general population the risk of bowel cancer is 1 in 14 for men and 1 in 19 for women.
Experts say there is still not enough evidence to recommend that fit and healthy people take
aspirin as a precaution against cancer. However, where there is a significant family history of
bowel cancer, and the risk of cancer is likely to be significantly higher than this, it is possible
that the advantages of taking aspirin outweigh the disadvantages.
Experts also state it is worth exploring whether some cancer patients, such as those with
bowel cancer, might benefit from daily aspirin. This is because there is evidence that aspirin
can reduce the risk of some tumours spreading to other parts of the body. However,
potential benefits need to be weighed up against the increased risk of bleeding for each
individual.
References
Rothwell PM, Price JF, Fowkes FGR, et al. Short-term effects of daily aspirin on cancer incidence, mortality,
and non-vascular death: analysis of the time course of risks and benefits in 51 randomised controlled
trials. Lancet Oncol. 2012; 13: 518-27.
Clinical Genetics, University Hospitals of Leicester
Written: 19/06/12, to be reviewed: 19/06/13