Aspirin linked to better survival rates for bladder and breast cancer

Taking aspirin at least three times a week is associated with increased survival rates from bladder and breast cancer, new research has shown.
 
However, the survival benefits decline over time, and the drug did not appear to affect survival rates in four other cancers – oesophageal, gastric, pancreatic and uterine – tracked in the large Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial study of nearly 140,000 Americans aged 65 and over.
 
One theory for the different survival rates put forward in the cohort study, published in JAMA Network Open, is that aspirin is known to block the COX-2 enzyme, which could play a role in the progression of breast and bladder cancer.
 
‘Although aspirin use at least three times [per] week was associated with the strongest risk reduction, any aspirin use was associated with increased bladder and breast cancer survival,’ the researchers wrote.
 
‘These results may indicate that for some cancer types, any aspirin use may be advantageous; however, greater benefit may be observed with increased frequency of use.
 
‘Although aspirin use may confer a cancer protective effect, it remains necessary to consider the harms, as well as the benefits, of long-term aspirin use.’
 
But despite its potential use post diagnosis, the researchers confirmed that aspirin was not associated with preventing the development of any of the six cancers in the cancer screening trial.
 
These findings are in line with a recent meta-analysis of 29 clinical trials testing whether aspirin could prevent cancer. It found that long-term aspirin use in people who did not have cancer ‘was not associated with a significant reduction in total cancer incidence, cancer mortality, or all-cause mortality’. It was, however, associated with a significant increase in the risk of bleeding.
 
In the US, daily aspirin is recommended for primary prevention of cardiovascular disease in people aged 50–59 at high risk of the disease. By contrast, Australia does not recommend this for cardiovascular disease, although the RACGP Red Book recommends aspirin as a preventive measure for people at high risk of colorectal cancer.
 
In the US, between a quarter and half of all adults report taking aspirin daily or every other day, with use increasing with age. These rates are much lower in Australia.
 
The widespread use of the medication for preventive purposes has been controversial since the 2018 publication of the Aspirin in Reducing Events in the Elderly (ASPREE) study, which found an increase in deaths from cancer in people aged over 65 who were not taking the drug before the study began.
 
In addition, low-dose aspirin use in people over 70 was linked to a higher risk of major haemorrhage, according to the ASPREE research.
 
‘The use of low-dose aspirin as a primary prevention strategy in older adults resulted in a significantly higher risk of major haemorrhage and did not result in a significantly lower risk of cardiovascular disease than placebo,’ the study found.
 
Professor Mark Nelson, a GP and Research Fellow at the University of Tasmania last year told newsGP that three major trials – ASPREE, ASCEND and ARRIVE – have ‘put the death knell in the use of aspirin for primary prevention’.
 
‘We regularly demonstrate bleeding risk without benefit, especially in the group that we’re dealing with – the aged – where the community level of gastrointestinal bleeding is relatively high compared to middle-aged populations,’ he said.
 
‘If somebody comes in and asks “Should I be taking aspirin?”, if they don’t have a clear clinical indication for its use, then the general recommendation should probably be no.’
 
Log in below to join the conversation.

aspirin cancer primary prevention