Scientists have reclassified breast cancer tumours into 10 categories according to genetic features that correlate with survival, in the largest global study of breast cancer tissue ever performed.

It is hoped that eventually doctors will be able to use these subtypes to predict more accurately a woman’s likely survival and to better tailor treatment to individual patients. The first tests to identify which group a woman belongs to are expected to be available in the NHS in three to five years.

Scientists at Cancer Research UK in Cambridge and the BC Cancer Agency in Vancouver, British Columbia, analysed DNA and RNA samples taken from tumours in 2000 women who had been given a diagnosis of breast cancer between five and 10 years ago. They identified genetic markers, determined which genes were switched on and off, and ascertained numbers of copies of …