Physician Photo

Leif William Ellisen, MD, PhD

Associate Physician, MGH Cancer Center

Clinical Director, Breast and Ovarian Cancer Genetics

Co-Executive Director, MGH Cancer Center Translational Research Laboratory

  • Phone: 617-726-6500
Department of Medicine


  • Cancer Center
  • Cancer Risk Assessment
  • Breast Cancer
Clinical Interests
Cancer genetics
Breast cancer
Boston: Massachusetts General Hospital
Concord: Emerson Hospital
Medical Education
MD, PhD, Stanford University School of Medicine
Residency, Brigham and Women's Hospital
Fellowship, Dana Farber Cancer Institute
Board Certifications
Medical Oncology, American Board of Internal Medicine
Foreign Languages
Patient Age Group
Accepting New Patients


Dr. Ellisen is a practicing oncologist and researcher at the Massachusetts General Hospital Cancer Center, an Associate Professor of Medicine at Harvard Medical School, and co-Executive Director of the Cancer Center's Translational Research Laboratory (TRL). 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 Mass General, respectively. Dr. Ellisen is widely published in the field of cancer biology and cancer genetics. His basic research efforts focus on chemosensitivity in breast and other cancers. His work in the TRL focuses on the clinical application of tumor genetic testing to advance the goal of personalized medicine. He serves on numerous grant review committees and editorial boards, and his work on personalized cancer medicine has been featured in the news media including the Wall Street Journal and the ABC Evening News.

ResearchOur research group is broadly interested in how genetic abnormalities within cancer cells influence their biology, and how that biology can in turn be exploited to therapeutic advantage. We address these questions through basic research studies of key tumor cell signaling pathways including p53, mTOR, and BRCA1/2. This work is complemented by genetic analysis of patient tumor samples conducted through our companion laboratory, the Mass General Cancer Center's Translational Research Laboratory (TRL). Finally, our discoveries in both the basic laboratory and the TRL are being applied in ongoing clinical trials which seek to identify predictive markers for response to specific therapeutic agents. Our ability to work at the interface of basic tumor biology and therapeutic application is strongly supported by the research and clinical infrastructure of the Cancer Center.

Translational Research Lab (TRL)

The Massachusetts General Hospital Cancer Center is committed to advancing oncology care by tailoring treatment options to the individual cancer patient. The basic mission of the Translational Research Laboratory (TRL) is to provide rapid personalized genomic testing as an important component of routine care, thereby minimizing generalizations made in treatment decisions.

Massachusetts General Hospital
55 Fruit Street
Boston, MA 02114-2696

Phone: 617-726-6500

Mass General Cancer Center at Emerson Hospital
133 Old Rd to Nine Acre Corner
Concord, MA 01742

Phone: 978-287-3436
Fax: 978-287-3642