Aspirin reduces colon cancer
"We are on the brink of a breakthrough of enormous importance," said Professor Peter Elwood (Cardiff University), speaking at the Aspirin Foundation conference Aspirin, Salicylates and Cancer at the Royal Society of Medicine in London on November 23rd.
Reviewing the implications of the latest research on aspirin in the prevention of cancer, Professor Elwood and a panel of experts considered how the new evidence could support an application for regulatory approval for aspirin to prevent cancer.
In October, researchers at Oxford University reported for the first time that aspirin has a long term protective effect against colorectal cancer.1 Lead investigator Professor Peter Rothwell told the conference that observational studies have linked aspirin use with a reduced risk of colorectal cancer. But these studies fall short of conclusive proof and confirmation is needed from prospective randomised trials. His team analysed four large trials involving a total of 14,000 people to show for the first time that, 20 years after regular use for an average of 6 years, aspirin reduced the risk of developing colon cancer by 24 per cent and cut the risk of dying from colon cancer by 35 per cent. However, this protective effect did not become apparent for 10 years.
The conference debated how the new evidence could change the way we use aspirin in clinical practice. Professor Gordon McVie, Senior Consultant at the Instituto Europeo Di Oncologia, Italy, said there is already enough evidence to target the use of aspirin at people with an increased risk of developing colorectal cancer. Professor Sir John Burn, Professor of Clinical Genetics, University of Newcastle, presented a clinical trial showing that aspirin reduces the risk of developing cancer in people with Lynch Syndrome, a genetic disorder which greatly increases risk of colorectal cancer. Aspirin and NSAID are associated with a reduced risk of relapse in people with cancer of the breast or colon, said Professor Jack Cuzick, Cancer Research UK Centre for Epidemiology, Mathematics and Statistics, University of London. If we also take into account aspirin's effect on reducing cardiovascular risk, Professor Elwood said, the balance of benefit and risk becomes more favourable for other people.
Dion Morton, Professor of Colorectal Surgery at the University of Birmingham, described the potential impact of aspirin on the way we detect and treat colorectal cancer now. "We're at a tipping point with screening, which offers the opportunity to reduce the risk of colorectal cancer. Evidence strongly suggests that aspirin can make a substantial contribution to that."
The therapeutic properties of salicylates were first described in 1763 but the protective effect of aspirin against cancer was reported only 20 years ago. Now, with convincing evidence of long term reduction in the risk of colorectal cancer, the conference agreed that the next step in aspirin's therapeutic development is to form an expert group to steer aspirin through the process of regulatory approval.