Patients with a wide range of cancers who take aspirin as part of their treatment could have their risk of death decrease by 20%, according to a major review of existing research.
Researchers at Cardiff University carried out a huge systematic review of 118 published observational studies in patients with 18 different cancers. Pooling the results, 250 000 patients with cancer who reported taking aspirin, which was associated with a reduction of about 20% in cancer deaths.
The review said the available body of evidence regarding its efficacy and safety “justifies its use” as a supplementary treatment in a wide range of cancers—and that patients should be made aware of this.
Lead author Professor Peter Elwood, Honorary Professor at Cardiff University who has studied the effects of aspirin for over five decades, said: “In recent years, my research team and I have been struck by the actions of aspirin on the biological mechanisms relevant to cancer—and these seem to be the same in many different cancers.
“We therefore wanted to review the scientific evidence available on the use of aspirin as an additional treatment for a wide range of cancers.
“Overall, we found that at any time after a diagnosis of cancer, about 20% more of the patients who took aspirin were alive, compared with patients not taking aspirin.”
The team took into consideration aspirin taking risks and wrote to an author on each of the papers asking about any stomach or other bleeding episodes.
A minority of patients had experienced a bleed, but no evidence of any excess deaths attributable to bleeding in the patients on aspirin was found, the review noted.
“Our research suggests that not only does aspirin help to cut risk of death, but it has also been shown to reduce the spread of cancer within the body—so-called metastatic spread,” said Prof Elwood.
“There is now a considerable body of evidence to suggest a significant reduction in mortality in patients with cancer who take aspirin—and that benefit appears to not be restricted to one or a few cancers.
“Aspirin therefore appears to deserve serious consideration as an adjuvant treatment of cancer and patients with cancer and their carers should be informed of the available evidence.
“However, we must also stress that aspirin is not a possible alternative to any other treatment.”
It started in 1974 when a research team led by Professor Elwood and Professor Archie Cochrane at the Medical Research Council’s Unit in Wales showed for the first time that taking an aspirin tablet a day reduced deaths from heart disease and stroke by about 24%.
In 1990, the finding gained global traction and was judged by the BMJ to have been one of the top 50 most important research studies published since 1945. A meta-analysis of 13 randomised controlled studies found a major adverse cardiovascular event risk reduction for statin users (12%), non-smokers (10%) and males (11%).
Prof Elwood said his original study stimulated a new phase of research work on aspirin. At the time of the report about 100 clinical research studies on aspirin were published each year—but now, in excess of 1 000 are reported each year. He said a number of new clinical trials had been set up to test aspirin treatment in several cancers and the results of these should offer further clear evidence.
“Further research into aspirin and cancer would clearly be of great value, and new studies should be encouraged, especially if focused on some of the less common cancers,” said Prof Elwood.
Source: Medical Xpress
Journal information: Peter C Elwood et al, Aspirin and cancer survival: a systematic review and meta-analyses of 118 observational studies of aspirin and 18 cancers, ecancermedicalscience (2021). DOI: 10.3332/ecancer.2021.1258
