A recent report that an individual’s genetic make-up could determine whether aspirin had a positive or negative effect on colorectal (bowel) cancer, is inconclusive said a leading cancer researcher and oncologist, Professor Peter Gibbs.
The JAMA paper, which was based on an analysis of 17,000 people from ten different studies, found that aspirin and NSAIDs (Non Steroidal Anti-Inflammatory Drugs) reduced the overall risk of colorectal cancer, however in 4% of participants with a rare genetic variation, the authors reported an increased risk of developing bowel cancer.
Prof Gibbs, an investigator on the cancer aspect of the ASPREE trial, said while the U.S. paper was interesting, the preliminary finding required further investigation before it could be considered valid.
“We don’t know the dose of aspirin, the duration of use, or the number of participants with and without the genetic variation, who took aspirin,” said Prof Gibbs, Joint Head of Division of Personalised Medicine at the Walter & Eliza Hall Institute for Medical Research in Melbourne.
“There may have been other influencing factors not measured in the analysis, and because the participants were all of European descent, they are not representative of the wider population.
“Age must be taken into consideration in any aspirin study. Some participants in this paper were on average up to 22 years younger than the average age of participants in the ASPREE trial. We know that the risk of developing cancer increases with age, as does the potential to experience side effects of aspirin – older people are under-represented in this report.”
Prof Gibbs said the overall balance of potential benefit versus the potential risk of aspirin needed to be known before healthy older adults could be advised whether to take aspirin to prevent cancer.
“This knowledge will come from the ASPREE trial,” he said.
In 2010, ASPREE established the ASPREE Healthy Ageing Biobank, a resource for possible genetic-focussed research in older people. More than 12,000 ASPREE participants donated blood samples to the Biobank when they enrolled in the trial, with many now volunteering an additional three year follow-up sample.
Prof Gibbs said that the discovery and validation of genetic patterns and markers from a high quality randomised clinical trial, such as ASPREE, could help doctors to accurately target therapies to prevent or treat diseases such as cancer in older people.
Results from the principal ASPREE trial should be available in 2018.
The report was published in JAMA (The Journal of American Medical Association).
Nan H, Hutter CM, Lin Y, et al. Association of Aspirin and NSAID Use With Risk of Colorectal Cancer According to Genetic Variants. JAMA. 2015;313(11):1133-1142. doi:10.1001/jama.2015.1815.
Updated 21.03.2021