She has worked closely with colleague Charles Perou to harness the power of microarray technology for recognizing and tailoring treatment for molecular subtypes of breast cancer. Carey's study was described in a 2006 Journal of the American Medical Association article, which is one of the highest impact articles on breast cancer and health disparities published to date. She is the principal investigator of a large-scale multi-institutional trial to test new treatments for a basal subtype of breast cancer. From 1990 to 1997, she was a resident in the School of Medicine's Department of Internal Medicine and a fellow in Oncology. She was nominated by Saraswati Sukumar, the Barbara B. Rubenstein Professor of Oncology and co-director of the Breast Cancer Program, Sidney Kimmel Comprehensive Cancer Center, School of Medicine.