Christine Brezden-Masley, MD PhD FRCPC is a senior practicing Medical Oncologist and the Medical Director of the Cancer Program at Sinai Health System in Toronto, Canada. She is also the Director of the Marvelle Koffler Breast Centre at Sinai Health and holds the Marvelle Koffler Chair in Breast Research. She obtained her PhD in Medical Biophysics at the Princess Margaret Hospital in Toronto and her Medical Degree from the University of Toronto. She is a Professor at the Temerty Faculty of Medicine, University of Toronto and an Associate Scientist at the Lunenfeld-Tanenbaum Research Institute, Toronto, Canada. 

She treats both breast and gastrointestinal (colorectal and gastric cancers) malignancies, which are her major areas of research interest. Her main area of clinical research is cardiotoxicity from cancer therapy and is the Past-President of the Canadian Cardio-Oncology Network (2017-2022). She also serves on the International Cardio-Oncology Society (ICOS) annual summit steering committees and co-chaired the 2022

Global Cardio-Oncology Summit in Toronto. She co-chairs the Junior Mentoring Program JuMP that fosters mentorship/sponsorship of junior medical oncology faculty across Canada and serves on the executive of WinC (Women in Cancer/All in Cancer).

She is an advocate for patients and serves as a board member of ReThink Breast Cancer and MyGutFeeling and also serves on the scientific committee for the Colorectal Cancer Resource & Action Network.