3 studies find aspirin reduces risk of cancer deaths, metastasis

Aspirin can reduce the risk for cancer-related mortality and can reduce or prevent the risk for distant metastasis, according to 3 new studies published online by The Lancet and The Lancet Oncology.

Aspirin was shown to reduce the risk for nonvascular death in all trials in The Lancetstudy authored by Peter M. Rothwell, FMedSci, and published online first on March 21.

Researchers in the United Kingdom reviewed 5 large, randomized trials of daily aspirin use versus control for the prevention of vascular events. Of 17,285 participants, 987 had a new solid cancer diagnosed during mean in-trial follow-up for 6.5 years. Those taking daily aspirin had a reduced risk of cancer with distant metastasis for all cancers.

In the study, aspirin also reduced death due to cancer in patients who developed adenocarcinoma, particularly in those without metastasis at diagnosis.

“That aspirin prevents distant metastasis could account for the early reduction in cancer deaths in trials of daily aspirin versus control. This finding suggests that aspirin might help in treatment of some cancers and provides proof of principle for pharmacological intervention, specifically to prevent distant metastasis,” the authors stated.

Rothwell and other researchers also reviewed the short-term effects of daily aspirin on cancer incidence and mortality. Those results also were published by The Lancet online on March 21. The researchers found that allocation to aspirin reduced cancer deaths (562 vs 644 deaths) in 51 randomized trials comparing daily aspirin use with no aspirin use for prevention of vascular events.

In the March 21 online edition of The Lancet Oncology, Rothwell and other researchers also reported evidence for benefits of long-term aspirin use for certain types of cancer. In case-control studies, regular use of aspirin was associated with reduced risk of colorectal cancer.

“Similarly consistent reductions were seen in risks of esophageal, gastric, biliary, and breast cancer,” the researchers stated.