Dr. Leif Ellisen is Breast Cancer Program Director and a senior Investigator at the Massachusetts General Hospital (MGH) Cancer Center, and Professor of Medicine at Harvard Medical School. He is also co-Leader of the Breast Cancer Program at the Dana-Farber Harvard Cancer Center. He received his undergraduate degree from Harvard University, MD and PhD degrees from Stanford University, and completed residency training, oncology fellowship training, and postdoctoral research training at Brigham and Women’s Hospital, the Dana-Farber Cancer Institute, and MGH, respectively. The Ellisen laboratory’s research is focused on the pathogenesis of breast and other cancers, with a particular focus on triple-negative breast cancer (TNBC), incorporating studies of tissue-specific development, transcription factor networks and DNA repair. The laboratory seeks to develop and apply a detailed molecular understanding of these factors in order to uncover new approaches for cancer prevention and treatment. For example, published work within the last five years identified for the first time a basal/luminal paracrine signaling program with relevance to breast cancer predisposition (Forster et al, Dev Cell 2014). Teams involving the Ellisen lab have recently discovered fundamental new genetic mechanisms in hormone receptor-positive breast cancer (Reinbay et al, Nature 2017; Matissek at al, Cancer Discovery 2018) and have revealed a new and therapeutically relevant signature of homologous recombination deficiency (Polak et al, Nature Genetics 2017). Work in the laboratory on a DNA damage response pathway led directly to a national clinical trial for TNBC at 10 major cancer centers (Isakoff et al, Journal of Clinical Oncology 2015), and to the discovery of a new oncogene controlling the tumor epigenome (Saladi et al, Cancer Cell 2017).

The Ellisen lab is uniquely positioned to work at the interface of basic tumor biology and therapeutic application. The lab’s work is strongly supported by a network of collaborators and by the extensive research and clinical infrastructure of the MGH Cancer Center and Harvard Medical School.