This new research fills in many of those gaps, opening the possibility of entirely new personalized treatments. It's part of a giant federal project to analyze the thousands of changes in the DNA of cell that lead to all kinds of cancer. It provides the strongest evidence breast cancer is not one disease but four major types and many subtypes.
This means some drugs already on the market to treat leukemia, melanoma, lung and other cancers might treat some breast cancer.
Doctors who treat women with breast cancer say patients need to know that while while these results are exciting, clinical trials are still needed - and those are likely.