BREAST CANCER: STEPS AND STUMBLES ON THE WAY TO PRECISION MEDICINE.

Treating breast cancer is both a success story and a lesson in the challenges of tailoring treatment to need. Beginning in the 1980s, multiple initiatives minimized surgical intervention and toxicity, integrated radiation therapy, and began to incorporate increasingly targeted medical therapy. Because of advances in treatment and screening, the U.S. mortality from breast cancer has dropped over 40%. However, these advances have come at a financial, physical, and social cost. It costs nearly $30 billion per year in the United States to achieve these improved outcomes in treating breast cancer, and we know that we overtreat many patients. Moreover, racial disparities in outcome persist, and many patients cannot access modern treatments. Ensuring that we give the right treatment to the right patient, and that we omit therapy when it is safe to do so, will require new strategies.