In what could prove to be a major breakthrough in treating breast cancer, Canadian scientists have found new breast cancer genes that has made it necessary to reclassify the disease into different categories.
Researchers at the BC Cancer Agency and University of British Columbia have reclassified the disease into 10 completely new categories based on the genetic fingerprint of a tumour.
Many of these genes could offer much-needed insight into breast cancer biology, allowing doctors to predict whether a tumour will respond to a particular treatment.
Whether the tumour is likely to spread to other parts of the body or if it is likely to return following treatment.
The study is the largest global study of breast cancer tissue ever performed and the culmination of decades of research into the disease.
In the future, this information could be used by doctors to better tailor treatment to the individual patient.
The team at the BC Cancer Agency, in collaboration with Cancer Research UK's Cambridge Research Institute and Manitoba Institute of Cell Biology at University of Manitoba, analyzed the DNA and RNA of 2,000 tumour samples taken from women diagnosed with breast cancer between five and 10 years ago.
The sheer number of tumours mapped allowed researchers to spot new patterns in the data.
The new discovery identified genes that were previously unknown to be linked to breast cancer and made it clear that breast cancer is an umbrella term for what really is a number of unique diseases.
Till now, breast cancer had been classified into four subgroups.
"This won't affect women diagnosed today. But in the future, patients will receive treatment targeted to the genetic fingerprint of their tumour," the Daily Express quoted Professor Carlos Caldas, senior group leader at the charity's Cambridge Research Institute, as saying.
"We've moved from knowing what a breast tumour looks like to pinpointing its molecular anatomy. Eventually we'll know which drugs it will respond to.
"The next stage is to discover how tumours in each subgroup behave - for example, do they grow or spread quickly?" Prof Caldas added.
The study has been recently published in the international journal Nature.