ABSTRACT
In the 19th century, the Scottish surgeon, Dr. Thomas Beatson, recognized that some, but not all, cases of advanced breast cancer would regress in response to “hormonal therapy,” which he administered in 1896 through surgical removal of the ovaries (1). Though it was not recognized at the time, Dr. Beatson had produced the first evidence that, despite arising from the same anatomic area and having similar histological appearance, not all breast cancers were biologically the same. In the decades that followed, we have made many advances in breast cancer therapy but we have made inadequate progress in determining which patients are most likely to benefit from which therapies, and in identifying patients at highest risk for recurrence.
