Women at high risk of developing breast cancer should be given preventative drugs, according to an international panel of cancer experts.
Writing in the Lancet Oncology, they said drugs such as tamoxifen could reduce the chances of developing breast cancer.
Such a policy would be similar to prescribing statins to patients at risk of heart disease, they suggest.
However, tamoxifen has been linked with womb cancer, blood clots and stroke.
In the UK, 46,000 women are diagnosed with breast cancer each year.
Two drugs, tamoxifen and raloxifene, have been approved in the US for the prevention of breast cancer. However, they are not available as a preventative measure in the UK.
Professor Jack Cuzick, who chaired the panel and is an epidemiologist at Queen Mary, University of London, told the BBC: "The two drugs should be approved in the UK. The evidence for them is overwhelming."