She specializes in the treatment of women's malignancies, with a particular emphasis on breast cancer, gynecologic malignancies, and the genetics of breast and ovarian cancer. Dr. Armstrong's clinical focus is on the development of new approaches to cancer treatment, particularly targeted biologic therapy and immunologic approaches. She is active in the American Society of Clinical Oncology, the Gynecologic Oncology Group, and the Society of Gynecologic Oncologists. Dr. Armstrong is on the advisory board of the Ovarian Cancer National Alliance and the National Ovarian Cancer Coalition. She also works as a scientific reviewer for the research programs of the Department of Defense and the National Cancer Institute.