Dr. Smith received her undergraduate degree from the Massachusetts Institute of Technology and earned her MD from Harvard Medical School's Harvard/MIT Division of Health Sciences and Technology and her PhD from Harvard University's Graduate School of Arts and Sciences. She completed her surgical residency at Brigham and Women's Hospital. She is a Professor of Surgery at Harvard Medical School and holds the MGH Trustees Chair in Breast Surgery. Dr. Smith has previously served as head of the MGH Breast Section, Director of the MGH Breast Program and Co-Director of the Women's Cancers Programs at MGH, BWH and DFCI.

Dr. Smith's research focuses on improving surgical techniques and surgical outcomes for women with breast cancer, including optimization of breast reconstruction and mastectomy techniques. Dr. Smith established MGH's nationally recognized nipple-sparing mastectomy program, where she conducts extensive studies that advance surgical and clinical practice in this area.  She led a series of multicenter, NIH-funded clinical trials of a novel fluorescence-guided intraoperative lumpectomy margin assessment tool that received FDA approval in 2024. She established and led the MGH-BWH Breast Surgery Fellowship and has been a research mentor for many fellows and students. She served as a Visiting Professor at Sun Yat-sen University in Guangzhou, China for 15 years, supporting the development of multidisciplinary breast cancer programs and clinical research initiatives.