The case for using aspirin to prevent cancer continues to build, particularly if people are at increased risk of the disease.
Three new studies, published in the medical journal The Lancet and in The Lancet Oncology, led by by Professor Peter Rothwell of the Nuffield Department of Clinical Neurosciences and colleagues at Oxford University also raise the possibility that a daily low dose of the drug could be effective, not just as a preventative measure, but as an additional treatment for those with cancer. It follows the finding that aspirin can reduce the chances of tumors spreading to other parts of the body.
Professor Rothwell says: ‘We are not at the stage of recommending aspirin use in everybody, but the guidelines on use of aspirin in the healthy middle-aged population certainly need to be updated in order to take into account the effects on the risk and outcome of cancer as well as on the risk of heart attacks and strokes.’
Previous studies by this team have established that aspirin reduces the long-term risk of dying from cancer, but that these effects don’t appear until about 8-10 years after starting taking a daily low dose of the drug. The short-term effects of aspirin were less certain.
‘What we have now shown is that aspirin also has short-term effects, which are manifest after only 2-3 years,’ says Professor Rothwell.
‘In particular, we show that aspirin reduces the likelihood that cancers will spread to distant organs by about 40-50%. This is important because it is this process of spread of cancer, or “metastasis”, which most commonly kills people with cancer.’
This reduction in the risk of a cancer spreading suggests that starting taking aspirin after being diagnosed could be beneficial – assuming that the cancer has not already spread.
Professor Rothwell says: ‘No drug has been shown before to prevent distant metastasis and so these findings should focus future research on this crucial aspect of treatment of patients with cancer that hasn’t already spread.
‘We argue in our papers that new trials are still required to confirm the benefit – but that such trials should be done urgently.’
Professor Rothwell explains which types of cancer see the biggest effect: “In terms of preventing spread of cancer, the data suggest that the effect is largest in adenocarcinomas. These include cancers of the gut, particularly colorectal cancer, some cancers of the lung and most cancers of the breast and prostate. In terms of preventing the longer-term development of new cancers, the largest reductions are seen in risk of colorectal cancer and oesophageal cancer, with smaller effects on several other common cancers.”