Breast cancer survivors who took aspirin after completing treatment were half as likely to die or have their tumors spread around the body compared with survivors who didn't take aspirin, a long-running study of 4,164 nurses showed.
The study is the first to find that regular aspirin users had a lower risk of dying from breast cancer, according to the study, published online today in the Journal of Clinical Oncology
Aspirin may help control cancer by fighting inflammation, says study author Michelle Holmes of Harvard Medical School and Brigham and Women's Hospital
. Breast cancers produce more inflammatory chemicals than normal breast cells. Lab tests show that aspirin keeps breast tumor cells from growing and invading other tissue.
A study in August also found that aspirin offered a potential benefit against colon cancer.
Yet neither study proves that aspirin keeps cancers in check, Holmes says. That's because doctors in each study merely followed patients for several years, noting which patients developed cancer and, of those, which took aspirin. So it's possible that something other than aspirin controlled their tumors, Holmes says.