Doctors' hopes for breast cancer prediction tests

A genetic test could help predict breast cancer many years before the disease is diagnosed, experts hope.

Ultimately the findings, by doctors at Imperial College London, could lead to a simple blood test to screen women.

The test looks for how genes are altered by environmental factors like alcohol and hormones - a process known as epigenetics.

Dr James Flanagan, who led the research, explains what it might mean for women at risk of breast cancer.