Aspirin ‘ineffective’ in cutting cancer risk in older adults: Study

A daily low dose of aspirin is ineffective in reducing the risk of cancer in healthy older adults, and ‘significantly’ increases the risk of cancer mortality, according to new research by Monash University.
 
The study, published in JAMA Oncology, shows low-dose aspirin treatment for a median of 4.7 years ‘had no effect on overall cancer incidence’, with researchers concluding that such a strategy is ‘not recommended’ in older adults.
 
Dr Michael Tam, a member of the RACGP Expert Committee – Quality Care, describes the Monash research as ‘a good study’ of high relevance to GPs.
 
‘It demonstrates an important finding that informs practice,’ he told newsGP.
 
The study followed more than 19,000 participants in Australia and the United States in the ASPREE (ASPirin in Reducing Events in the Elderly) project, a long-term, two-part study.
 
The first part of the study comprised a randomised, blinded, placebo-controlled clinical trial of 19,114 Australian and American adults from 2010 to 2017, in which participants were randomly allocated a daily 100 mg dose of aspirin, or a placebo.
 
The second part was the ASPREE-eXTension study, a follow-up observational phase from 2018 to 2024 in which participants ceased taking the aspirin or placebo.
 
Australian participants were all aged 70 or over, while the US participants were 65 years or older from minority groups.
 
The study’s first author, Associate Professor Suzanne Orchard, said there was ‘overall no change’ in cancer incidence among participants assigned the low-dose aspirin in the original trial compared to the placebo group, but cancer mortality ‘remained significantly elevated by 15%’.
 
‘However, the elevated cancer mortality risk seen with aspirin for participants in the original ASPREE trial period did not persist into the post-trial ASPREE-eXTension study, suggesting no lasting aspirin effect, although longer follow up of the cohort is warranted,’ she said.
 
‘From these findings, commencing a program of low-dose aspirin for a number of years for the prevention of cancer is not recommended in older adults.’
 
Prior studies, largely of middle-aged adults, report taking aspirin reduced the risk of cancer after 10 years, particularly for colorectal cancer. 
 
Dr Tam does not believe the Monash findings change that advice.
 
‘We have reasonable evidence to support the use of aspirin to prevent colorectal cancer, especially people at elevated risk,’ he said. ‘I don’t think this has changed.’
 
However, he said it is uncertain whether the beneficial effects of aspirin continued for older people.
 
‘There is the broader question that GPs often face: at what point medicines that are used for prevention should stop, and whether doing so would be harmful,’ he said.
 
‘This study supports the stopping of aspirin for this purpose.’
 
Log in below to join the conversation.
 

aspirin ASPREE bowel cancer colorectal cancer