Breast cancer is “not one disease, but 10 different diseases”, according to a “landmark” study that could revolutionise its treatment.
An international team of researchers that analysed breast cancers from 2,000 women said the classifications could help improve treatment by tailoring drugs for patients' exact type of breast cancer and also predict survival more accurately.
It will take at least three more years for the findings to be used in hospitals, the researchers said. In the study, published in the journal Nature, the team analysed genetics of frozen breast cancer samples from 2,000 women at hospitals in the UK and Canada.
They looked in huge detail at the genetics of the tumour cells — which genes had been mutated, which genes were working in overdrive, which were being shut down. They found that all the different ways the cells changed when they became cancerous could be grouped into 10 different categories, named IntClust one to 10. Each tumour within a particular group shares similar genes and different women with the same type have similar odds of survival.
“Breast cancer is not one disease, but 10 different diseases,” lead researcher Prof Carlos Caldas, was quoted as saying by the BBC News.
He added: "Our results will pave the way for doctors in the future to diagnose the type of breast cancer a woman has, the types of drugs that will work and those that won't, in a much more precise way than is currently possible." At the moment, breast cancers are classified by what they look like under the microscope and tests for "markers" on the tumours.
Dr Harpal Singh, of Cancer Research UK that funded the study, said: “The study will change the way we look at breast cancer, it will have an enormous impact in diagnosing and treating breast cancer."