LONDON: A regular dose of aspirin can reduce the long-term risk of cancer in those who are overweight, according to an international study of people with a family history of the disease.
The study found that being overweight more than doubled the risk of bowel cancer in people with Lynch Syndrome, an inherited genetic disorder which affects genes responsible for detecting and repairing damage in the DNA.
Around half of these people develop cancer, mainly in the bowel and womb.
Over the course of a ten year study, researchers from Newcastle University and the University of Leeds in UK found this risk could be counteracted by taking a regular dose of aspirin.
"This is important for people with Lynch Syndrome but affects the rest of us too," said Professor Sir John Burn, professor of Clinical Genetics at Newcastle University, who led the international research collaboration.
"Lots of people struggle with their weight and this suggests the extra cancer risk can be cancelled by taking an aspirin," said Burn.
"This research adds to the growing body of evidence which links an increased inflammatory process to an increased risk of cancer. Obesity increases the inflammatory response.
"One explanation for our findings is that the aspirin may be suppressing that inflammation which opens up new avenues of research into the cause of cancer," Burn said.
The randomised controlled trial is part of a study involving scientists and clinicians from over 43 centres in 16 countries which followed nearly 1,000 patients with Lynch Syndrome, in some cases for over 10 years.
In the research, 937 people began either taking two aspirins (600 mg) every day for two years or a placebo. When they were followed up ten years later, 55 had developed bowel cancers and those who were obese were more than twice as likely to develop this cancer - in fact 2.75 times as likely.
Following up on patients who were taking two aspirins a day showed that their risk was the same whether they were obese or not.
"For those with Lynch Syndrome, we found that every unit of BMI above what is considered healthy increased the risk of bowel cancer by 7 per cent," said John Mathers, professor at Newcastle University, who led this part of the study.
"What is surprising is that even in people with a genetic predisposition for cancer, obesity is also a driver of the disease. Indeed, the obesity-associated risk was twice as great for people with Lynch Syndrome as for the general population," Mathers said.
"Our study suggests that the daily aspirin dose of 600 mg per day removed the majority of the increased risk associated with higher BMI," said Tim Bishop from the University of Leeds, who led on the statistics for the study.
The study was published in the Journal of Clinical Oncology.