Doctors now know that breast cancer is not one disease, but actually an amalgam of 10.
The major international study, published in Nature on Wednesday, classified the disease into 10 subtypes, in addition to finding several new genes that drive breast cancer.
Reuters reports that the findings mean that doctors will be able to better tailor treatment for patients in the future, in addition to highlighting new targets for new kinds of drugs.
Scientists at Cancer Research UK (CRUK) led the study told Reuters the findings also mean that breast cancer ought to be considered not as one disease, but an "umbrella term" for 10 diseases.
Co-leader of the study Carlos Caldas also told the news organization that science has gone from knowing what a breast tumor looks like underneath the microscope to "pinpointing its molecular anatomy."
According to Time, the research team looked at 997 breast tumors from nearly 2,000 women from the U.K. and Canada who were diagnosed between five and 10 years ago. At the end of the study, researchers had determined the "genetic fingerprints" of 10 different classifications of tumors, and then re-tested those classifications to confirm the findings.
Those classifications, wrote the L.A. Times, range "from very treatable to extremely aggressive" – information that will be useful to scientists trying to determine what treatment to prescribe.
"This is going to have a huge impact on the way we think about breast cancer," Raju Kucherlapati, a genetics professor at Harvard Medical School, told the Times. "Together with data coming out in the next few months, I think the whole landscape of research, discovery and treatment is going to change."
CRUK's chief executive Harpal Kumar echoed Kucherlapati, telling Reuters the findings change "the way we think about breast cancer – no longer as one disease, but actually as 10 quite distinct diseases depending on which genes are really switched on and which ones aren't."
The American Cancer Society estimates that in 2012, the U.S. will see 229,060 new cases of breast cancer and 39,920 deaths from the disease. Of those new cases and deaths, approximately 226,870 and 39,510, respectively, will be female.
In Los Angeles County, nearly 114 out of every 100,000 women have invasive breast cancer, according to a 2010 report by the L.A. County Department of Public Health.
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