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Leif William Ellisen, MD, PhD

Program Director, Breast Medical Oncology

Clinical Director, Breast and Ovarian Cancer Genetics

Associate Physician, MGH Cancer Center

As Program Director for Breast Medical Oncology, Dr. Ellisen oversees an integrated and multidisciplinary unit focused on excellence in patient care and groundbreaking clinical and translational research.

  • Phone: 617-726-6500
Department of Medicine


  • Cancer Center
  • Cancer Risk Assessment
  • Breast Cancer
Clinical Interests
Cancer genetics
Breast cancer
Boston: Massachusetts General 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
Accepting New Patients

BiographyDr. Ellisen is Professor of Medicine at Harvard Medical School and Program Director for Breast Medical Oncology at the Mass General Cancer Center. 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 Mass General, respectively. Dr. Ellisen is widely published in the fields of cancer biology, treatment and genetics. As Director of Breast and Ovarian Cancer Genetics at Mass General, Dr. Ellisen's clinical practice is focused on cancer risk assessment, cancer prevention and early detection. Research in Dr. Ellisen's laboratory is in the vanguard of revolutionizing cancer treatment through personalized cancer therapies. Dr. Ellisen is best known for his work on triple-negative breast cancer (TNBC), one of the most aggressive forms of the disease.

ResearchIn the Ellisen Laboratory, scientists identify genetic abnormalities in tumor cells that are not present in normal tissues, study how the abnormalities influence the biology of cancer cells, and explore how their new discoveries can inform the selection of the most effective therapy for each patient. Key tumor cell pathways under investigation in the laboratory include p53, BRCA1/2, and mTOR. Dr. Ellisen is best known for his work on triple-negative breast cancer (TNBC), one of the most aggressive forms of the disease. His research has shown that a chemotherapy drug used to treat several other types of cancer - but rarely breast cancer - holds promise for TNBC patients. Dr. Ellisen now oversees clinical trials of this and many other promising new therapies in breast cancer.

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.

Screening for breast/ovarian cancer risk genes other than BRCA1/2 can change clinical recommendations

A study by researchers at three academic medical centers has shown that screening women with a suspected risk of hereditary breast or ovarian cancer for risk-associated genes other than BRCA1 and 2 provides information that can change clinical recommendations for patients and their family members.

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

Phone: 617-726-6500

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

Phone: 617-726-6500

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