The old stand-by drug, aspirin, has been replaced in many medicine cabinets by other pain-killers and headache and fever reducers. Due to its effect on the lining of the stomach and the risk of bleeding and ulcers, aspirin is generally taken regularly only by those with a risk of heart disease.

But researchers have found evidence in test-tube experiments that aspirin has angiogenesis-blocking power, that is, it keeps cancers from creating the blood vessels they need to grow. They caution that these tests have not been done in humans yet and that no one should start taking aspirin to ward off cancer.

Aspirin May Be Newest Cancer Drug - WebMD