According to a long-running study, 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. 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. Patients who are being treated for cancer usually are told to avoid aspirin because it can act like a blood thinner. That could be a problem for women who are having radiation and chemotherapy, which also lower the number of blood cells. For proof, doctors would need to conduct a "gold standard" trial in which doctors randomly assign one group of patients to take a aspirin, then compare their progress with patients randomly assigned to a placebo. Until then, breast cancer survivors should be cautious about aspirin and consult their doctors before taking it.