Aspirin has the properties of preventing breast cancer

According to a new study  daily low dose of aspirin can block breast tumour growth and prevent deadly relapses.

Acetylsalicylic acid (or, aspirin) seems to do the job by producing conditions that inhibit the reproduction of cancer forming stem cells, say researchers from the Cancer Research Unit at Kansas Veteran Affairs Medical Center. Previous studies have already shown aspirin's beneficial effect on colon, gastrointestinal, prostate and other cancers. Source