About Leif Ellisen, MD, PhD

Dr. 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.

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Locations

Massachusetts General Hospital
55 Fruit St.
Boston, MA 02114
Phone: 617-726-2000

Medical Education

  • PhD, Stanford School of Medicine
  • MD, Stanford University School of Medicine
  • Residency, Brigham and Women's Hospital
  • Fellowship, Dana Farber Cancer Institute
  • Fellowship, Massachusetts General Hospital

Note: This provider may accept more insurance plans than shown; please call the practice to find out if your plan is accepted.


Research

In 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.

Publications

Reviews: Comments and Ratings

5.0out of 5(43 Ratings, 23 Comments)

January 2025

Dr. Ellisen is a true professional. He's extremely knowledgeable. He shares his knowledge. He's patient. He's kind. He listens. And I would give him a 10 in every way possible. I also am so impressed with the woman that checks everyone in at the front desk. She's been with Mass General for 27 years. Hopefully she gets some type of raise because ... Read More


December 2024

Dr. Ellisen is the absolute BEST. I am so happy that he is my doctor. He is patient and caring and so knowledgeable about breast cancer care.


November 2024

Fantastic


October 2024

He's outstanding and I'm fortunate to have him. He is easy to contact and responsive.


October 2024

Yes. Regarding Dr. Leif Ellisen, I am very pleased, extremely. He is excellent. I have gone to him for six years now and thankfully for a breast check due to, I'm sorry, some kind of, I have a lobular, I do apologize, I can't even talk today. Anyway, it's in my file and he's been seeing me and treating me wonderful. I didn't need any procedures. I ... Read More


October 2024

I cannot say enough good things about Dr. Ellisen's care and willingness to listen and take into account a different perspective. And making his recommendations clear and answering all questions.


October 2024

Thoughtful kind and took time to think through best next steps in care plan.


October 2024

Dr. Ellisen is always professional, kind, informative, and very, very easy to deal with and work with. He's a pleasure to have as a care provider.


October 2024

superior doc


September 2024

Dr. Ellisen is an outstanding physician. He is always so welcoming and approachable and remembers my history despite having hundreds of other patients. He explains complex information in a very accessible manner and I leave feeling more optimistic about my future health outlook.

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