Personalized Medicine for Breast Cancer
This is part three in our special report series on breast cancer in honor of October’s Breast Cancer Awareness month. In this article, we hear from two award-winning scientists: James Hicks, PhD, of the Cold Spring Harbor Laboratory, and Peter Kuhn, PhD, of the University of Southern California. Both work with the Breast Cancer Research Foundation (BCRF) on the cutting edge of using personalized medicine to treat and diagnose breast cancer.
What is personalized medicine as it relates to breast-cancer treatment?
KUHN: The practice of medicine has always been personalized through the patient–physician interaction, but the technologies have not been able to provide truly biologically informed, complete knowledge of the disease at every point in time of its progression. It is the latter that we need to bring to breast-cancer care.
HICKS: In every clinical trial there are patients who respond well and those who do not. Personalized treatment results when you know ahead of time which patients will respond best to a particular treatment. The goal is to find characteristics that mark certain cases as potential responders to specific treatments. Breast cancer currently has two strong drivers: expression of the estrogen receptor in about 50 percent of cases, leading to treatments focused on that hormone, and overexpression of the HER2/neu protein in another 25 percent, which indicates treatment with drugs, such as Herceptin, that block that growth pathway. But neither treatment is 100 percent successful, and 25 percent of patients have “triple negative” disease, meaning they lack both biomarkers, so more work needs to be done.
We also know that cancers can change as they progress, so decisions made by testing a single surgical sample at the beginning of treatment may not be relevant a few months or years later. The breakthrough potential of the fluid biopsy is that through repeated tests, using a simple blood draw, we can follow the changes in a cancer in real time and adjust treatments to target the altered cells.
(Continues on next page...)