Daily aspirin could help prevent hereditary form of bowel cancer

Scientists in the UK have found that a daily dose of aspirin may halve the chance of men with Lynch Syndrome developing colon cancer, one of the three most common cancers in developed countries. Lynch Syndrome is an inherited condition, which increases vulnerability to cancers of the colon, rectum, stomach, brain, liver, womb and elsewhere. Whilst the syndrome only accounts for five per cent of all colon cancer cases, the new findings are significant because men with the condition normally have about a 90 per cent chance of developing colon cancer before old age. In the UK, colon cancer kills over 16,000 people annually, which is almost half of all diagnosed cases. The scientists, from the University of Newcastle, hope that their findings may lead to new cancer treatments by helping researchers understand how aspirin combats the cancer, something that they are unsure of at this time. The results were presented recently at the joint ECCO-ESMO annual conference in Berlin.

The Newcastle study included 1,071 people with Lynch Syndrome from 16 countries. Participants either took a 600mg dose of aspirin daily, or a placebo. The investigators conducted follow-up tests after 10 years and found that neither treatment had an effect on whether patients developed the cancer or not after 29 months. However, after four years a trend seemed to have developed, only six people developed colon cancer in the aspirin group compared to 16 in the placebo group. 'We are delighted!' said Professor John Burn of Newcastle University's Institute of Human Genetics, adding: 'All the more so because we stopped giving the aspirin after four years, yet the effect is continuing.' Overall the researchers have estimated that aspirin reduced the chance of patients developing cancer by roughly 50 per cent.

'This doesn't mean that everyone should start taking aspirin if they're worried about bowel cancer. Aspirin can cause significant side-effects if not used as directed by a doctor,' warned Henry Scowcroft, of Cancer Research UK. In the Newcastle study 11 patients developed internal bleeding and stomach ulcers compared with nine on the placebo.

Although the findings will have no immediate impact on the general public, the researchers hope it may shed some light on the mechanisms involved when cancers develop. Previous studies found that patients with colon cancer who are being treated with chemotherapy and surgery may reduce their risk of dying by up to 30 per cent if they take aspirin as well. However, scientists are still unsure of exactly how aspirin fights cancer. Although there is some disagreement among cancer researchers, Burn believes that the drug may be affecting cancer stem cells. He hypothesises that the drug may speed up the process of cells destroying themselves when they pick up the 'genetic spelling mistakes' that can be cancerous, thereby offering some protection against cancer ever developing in the first place. He is now planning a follow-up study with about 10 times as many people to see whether a smaller dose of aspirin could provide the same protective benefits.