Breast-Cancer Therapy — Looking Back to the Future

Adjuvant therapy for breast cancer — treatment after surgical removal of the tumor — is a major therapeutic advance that has had a considerable effect on prolonging disease-free and overall survival. Not all patients benefit from adjuvant therapy, however, and certain types of adjuvant therapy are not appropriate for some patients. For example, adjuvant treatment with tamoxifen, a selective estrogen-receptor modulator, has improved the 15-year survival rate among women with estrogen-receptor–positive breast cancer by 31%, but it does not benefit women with estrogen-receptor–negative disease.1 Trastuzumab, a monoclonal antibody against the human epidermal growth factor receptor type 2 (HER2), is associated . . .