From 2001 to 2019, she served as Clinical Director and Chief of the External Beam Radiotherapy – Manhattan Service in the Department of Radiation Oncology. She was also the department’s Acting Chair from 2005 to 2008. Over a 50-year career, Dr. McCormick held academic appointments at both MSK and Weill Cornell Medicine.
Dr. McCormick was a founding member of the National Comprehensive Cancer Network (NCCN) guidelines committee and helped shape clinical breast cancer research during its formative years. Her work on breast cancer treatment guidelines, including consensus statements from the American Society for Radiation Oncology (ASTRO) that are used worldwide, is widely cited.
Many of her most significant contributions date to her time leading the breast cancer steering committee of the Radiation Therapy Oncology Group (RTOG), before it was consolidated into NRG Oncology. She contributed to many influential trials in early-stage breast cancer, including a clinical trial that established an option to omit radiation for older patients with low-risk disease.
She is best known for leading a trial in low-grade ductal carcinoma in situ (DCIS) that compared wide local excision with and without radiation therapy. The study showed that radiation clearly reduced local recurrence, although the risk was low in both groups.