GPs urged to use aspirin in patients at colorectal Ca risk
GPs should consider prescribing a daily dose of aspirin to patients at risk of colorectal cancer, new research suggests.
A study published in the latest issue of The Lancet found long-term use of 300mg or more of aspirin a day for five years was effective at preventing colorectal cancer, writes Cato Pedder.But an accompanying commentary warned against rushing to increase aspirin use and insisted it was not yet proven that the benefits outweighed the risks.The study determined the long-term effect of aspirin by following up patients from two large randomised trials performed in the late 1970s and early 1980s involving 7,588 patients. It found use of aspirin for five years reduced the subsequent incidence of colorectal cancer by 37% overall, and by 74% 10-15 years after treatment was started.Professor Peter Rothwell, leader of the study, said aspirin cut the incidence of colorectal cancer by so much that those at risk of the disease, including those with a family history or colorectal polyps, should consider taking it daily. GPs might now decide to use aspirin in preference to newer, more expensive antiplatelet drugs in patients with vascular disease because of the added protective benefits, he added.Professor Rothwell, professor of clinical neurology at the University of Oxford, said: 'The main group at risk of colorectal cancer is those with a family history of the disease; they are two to four times more likely to get it. So to have their risk reduced by a half to three-quarters would be worthwhile.'But in the accompanying commentary Dr Andrew Chan, a gastroenterologist in the Massachusetts General Hospital, US, said: 'With the concerns about the potential risks of long-term aspirin use and the availability of alternative prevention strategies, for example screening, these findings are not sufficient to warrant a recommendation for the general population to use aspirin for cancer prevention.'But Professor Rothwell said Dr Chan was talking from a US perspective where screening for colorectal cancer was much more widespread than in Europe. He claimed the study was a significant step forward in preventing cancer. 'Now we have proven aspirin can prevent at least one cancer, it might be worth looking in more detail at other cancers,' he said.
How aspirin cuts cancer risk• Long-term use of 300mg or more of aspirin a day for five years can prevent colorectal cancer• Effect is only seen after latency of 10 years• Protective benefits of aspirin are not related to age, sex, race or country in which study was carried out• Aspirin equally effective in individuals with and without family history of colorectal cancer