Patients receiving cancer treatment could increase their chance of survival by up to 20% and help stop their cancer from spreading by taking a low-dose of aspirin, new research suggests. In a systematic review of the available scientific literature a team from Cardiff University's School of Medicine found a significant reduction in mortality and cancer spread by patients who took a low-level dose of aspirin in addition to their cancer treatment (average study follow-up length over 5 years). 

"There is a growing body of evidence that taking aspirin is of significant benefit in reducing some cancers," said Professor Peter Elwood who led the research published in the journal PLOS ONE. 

"Whilst we know a low-dose of aspirin has been shown to reduce the incidence of cancer, its role in the treatment of cancer remains uncertain. As a result, we set out to conduct a systematic search of all the scientific literature."

The team's review looked at all of the available data including five randomised trials and forty two observational studies of colorectal, breast and prostate cancers. 

Professor Elwood said: "Our review, based on the available evidence, suggests that low-dose aspirin taken by patients with bowel, breast or prostate cancer, in addition to other treatments, is associated with a reduction in deaths of about 15-20%, together with a reduction in the spread of the cancer. 

"The results from six studies of other cancers also suggest a reduction, but the numbers of patients were too few to enable confident interpretation. A mutation - known as PIK3CA - was present in about 20% of patients, and appeared to explain much of the reduction in colon cancer mortality by aspirin.

"One of the concerns about taking aspirin remains the potential for intestinal bleeding. That's why we specifically looked at the available evidence of bleeding and we wrote to all authors asking for further data. In no study was serious or life-threatening bleeding reported."