Taking a low-dose aspirin every day will reduce your chances of dying from cancer, scientists say today, confirming the over-the-counter pills as the most extraordinary drug yet discovered.
Daily aspirin has already been shown to cut the chances of heart attacks and stroke in people who are at risk. The study public today in the Lancet medical journal reveals that it also has a powerful preventive action against a range of cancers and possibly more of them than there is currently enough evidence to prove.
While the doctors who carried out the study say it is not for them to make recommendations, the lead author, 46-year-old Prof Peter Rothwell from Oxford University, says he has been taking aspirin for the last two years. The beneficial dose is 75mg - a quarter of a standard tablet, which is 300mg. Some pharmacies sell low-dose tablets, but at a higher price.
Rothwell and his colleagues have already shown that daily aspirin cuts death rates from colorectal cancer by more than a third. For the study published today, they examined all the data they could find from well-conducted trials that had assessed the use of aspirin against a control drug and had recorded deaths from cancer.
In eight trials involving more than 25,000 patients, they found there were 21% fewer deaths after five years among those who took a daily aspirin tablet, compared with those who did not. The effect was most noticeable in gastrointestinal cancers, where deaths dropped by 54%.
Patients in aspirin trials 20 years ago were still 20% less likely to die of a solid tumor and 35% less likely to die of gastrointestinal cancer.
They found that the effects of the aspirin seemed to kick in for pancreatic, brain, esophageal and lung cancer (generally not the sort triggered by smoking) after patients had been taking it for five years or more. For stomach and colorectal cancer, the effects were seen after 10 years and for prostate cancer after 15 years. After 20 years, the risk of death from prostate cancer was reduced by 10%, for lung cancer by 30%, for colorectal cancer by 40% and for esophageal cancer by 60%.
The scientists believe benefits may be even greater than they could establish.
The impact on pancreas, stomach and brain cancers was difficult to quantify exactly because of smaller numbers of deaths, they say. There could be an effect in breast and ovarian cancers, but there is not enough trial data to prove it.
Those in the trials took aspirin for only four to eight years. Rothwell believes that if people took aspirin for 20-30 years, from the age of around 45 or 50, they might substantially reduce the risk of cancer, which steadily increases as people age.
Rothwell and colleagues believe their findings should tip the balance of risk/benefit in favour of daily aspirin dosing. While millions of people started taking the tablets after evidence that it cut their chances of heart attacks and stroke, there has been something of a medical back-pedaling, because aspirin can cause stomach bleeding.
1. Over-the-counter pills refer to drugs that can be obtained（ ）.
2. Which of the following is NOT true?
3. The effect of a daily aspirin tablet was most noticeable in（ ）.
4. How many years did those patients take aspirins in the eight trials?
5. For colorectal cancer, the effects of the aspirin were seen after（ ）years.
