Research has shown that a regular dose of aspirin reduces the long-term risk of cancer in those who are overweight in an international study of people with a family history of the disease due to Lynch syndrome. The study was published in the Journal of Clinical Oncology (2015; doi:10.1200/JCO.2014.58.9952).
The research team, from Newcastle University and the University of Leeds in the United Kingdom, found that being overweight more than doubles 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. Approximately half of these people develop cancer, mainly colorectal and uterine cancers.
However, over the course of a 10-year study, the team 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. Lots of people struggle with their weight and this suggests the extra cancer risk can be cancelled by taking an aspirin,” said study leader Professor Sir John Burn, MD, professor of Clinical Genetics at Newcastle University.
“This research adds to the growing body of evidence [that] 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.”
The randomized controlled trial is part of the CAPP 2 study involving scientists and clinicians from more than 43 centers in 16 countries that followed nearly 1,000 patients with Lynch syndrome, in some cases for more than 10 years.
A total of 937 people began taking two aspirins (600 mg) every day for 2 years or taking a placebo. At 10-year follow-up, 55 participants had developed colorectal cancers and those who were obese were more than twice as likely to develop this cancer, in fact, 2.75 times as likely. Patients who took two aspirins a day had the same risk regardless of whether they were obese.
The trial was overseen by Newcastle Hospitals NHS Foundation Trust and funded by the UK Medical Research Council, Cancer Research UK, the European Union, and Bayer Pharma.
“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%,” said co-author Professor John Mathers, PhD, professor of Human Nutrition at Newcastle University. “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.
“The lesson for all of us is that everyone should try to maintain a healthy weight and for those already obese the best thing is to lose weight. However, for many patients this can be very difficult so a simple aspirin may be able to help this group.”
The international team is now preparing a large-scale follow-up trial and wants to recruit 3,000 people across the world to test the effect of different doses of aspirin. The trial will compare two aspirin a day with a range of lower doses to see if the protection offered is the same. Information on the next trial can be found at www.capp3.org.