Breast cancer is actually 10 different diseases

Classification As Per Genetic Study To Revolutionize Treatment By Tailoring Drugs For Exact Subtype

London: Breast cancer is “not one disease, but 10 different diseases”, according to a ‘landmark study’ that could revolutionize 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 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 professor 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 manner 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. Those with “oestrogen receptors” should respond to hormone therapies, while those with a “Her2 receptor” can be treated with Herceptin.

    The vast majority of breast cancers, over 70%, should respond to hormone therapies. However, their reaction to treatment varies wildly. “Some do well, some do horribly. Clearly we need better classification,” said Caldas.

    Dr Harpal Singh, of Cancer Research UK that funded the study, said, “This study will change the way we look at breast cancer, it will have an enormous impact in diagnosing and treating breast cancer.”

    He added the charity would begin using the new criteria in clinical trials it funded. Outside of trials for new cancer drugs, the new breast cancer rulebook could take some time to directly benefit patients.