There’s been some news about a study which suggests that aspirin might prevent cancers spreading to other parts of the body.
It’s been suspected for a while that aspirin might have anti-cancer effects. For example, there’s evidence it can prevent or slow the development of bowel polyps – the pre-malignant phase of colorectal cancer. There’s also some evidence of breast cancer risk reduction.
This study was in mice, not humans. And the cancer the mice were susceptible to was melanoma. The mice given aspirin were much less likely to develop melanoma metastases (cancer spread). The explanation is complex. Aspirin inhibits the action of platelets, the tiny cells in the bloodstream involved in blood clotting. It does this by interfering with a particular enzyme. It turns out that this enzyme also exists in immune system cells called T cells which are involved in cancer control. Aspirin in these mice appeared to be acting like immunotherapy by unleashing these T cells allowing them to attack and mop up melanoma cells which might have been released into the bloodstream.
It’s an exciting finding but….. and there’s always a but….. this was in mice and mice aren’t humans. And it was in melanoma which is known to be a cancer that’s particularly sensitive to the immune system. Whether this is generalisable to people and other cancer types remain to be seen.
Who benefits from low-dose aspirin?
The evidence is that taking low dose aspirin when you’re otherwise healthy has no benefits and only risk from bleeding and injury. A huge Australian study of many thousands of people with no heart disease or cancer who were given aspirin to prevent these diseases arising, found no effect.
The people who do benefit from low dose aspirin – and very significantly – are those who have had a heart disease event of some kind for instance a stroke, a short-lived stroke (used to be called a transient ischaemic attack), a heart attack, angina (chest pain on exertion), or have need a stent or cardiac procedure. The reason aspirin works in these situations is that the arteries have areas of damage on which blood clots can form therefore the anti-platelet effect of aspirin can stop or reduce the risk of that happening.
Aspirin is not a medication to start without first discussing with your GP.
